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Message-Id: <20191120073622.37938-3-tali.perry1@gmail.com>
Date: Wed, 20 Nov 2019 09:36:22 +0200
From: Tali Perry <tali.perry1@...il.com>
To: robh+dt@...nel.org, mark.rutland@....com, yuenn@...gle.com,
venture@...gle.com, benjaminfair@...gle.com,
avifishman70@...il.com, joel@....id.au, tmaimon77@...il.com,
wsa@...-dreams.de, syniurge@...il.com
Cc: linux-i2c@...r.kernel.org, openbmc@...ts.ozlabs.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Tali Perry <tali.perry1@...il.com>
Subject: [PATCH v6 2/2] i2c: npcm: Add Nuvoton NPCM I2C controller driver
Add Nuvoton NPCM BMC i2c controller driver.
Signed-off-by: Tali Perry <tali.perry1@...il.com>
---
drivers/i2c/busses/Kconfig | 11 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-npcm7xx.c | 2486 ++++++++++++++++++++++++++++++
3 files changed, 2498 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 146ce40d8e0a..9091b93aaf90 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -786,6 +786,17 @@ config I2C_NOMADIK
I2C interface from ST-Ericsson's Nomadik and Ux500 architectures,
as well as the STA2X11 PCIe I/O HUB.
+config I2C_NPCM7XX
+ tristate "Nuvoton I2C Controller"
+ depends on ARCH_NPCM7XX
+ select I2C_SLAVE
+ help
+ If you say yes to this option, support will be included for the
+ Nuvoton I2C controller.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-npcm7xx.
+
config I2C_OCORES
tristate "OpenCores I2C Controller"
help
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3ab8aebc39c9..4af59a806f3c 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_MXS) += i2c-mxs.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
+obj-$(CONFIG_I2C_NPCM7XX) += i2c-npcm7xx.o
obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
obj-$(CONFIG_I2C_OMAP) += i2c-omap.o
obj-$(CONFIG_I2C_OWL) += i2c-owl.o
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
new file mode 100644
index 000000000000..3418ee049294
--- /dev/null
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -0,0 +1,2486 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NPCM7xx SMB Controller driver
+ *
+ * Copyright (C) 2018 Nuvoton Technologies tali.perry@...oton.com
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk/nuvoton.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/jiffies.h>
+
+#define I2C_VERSION "0.1.0"
+
+enum smb_mode {
+ SMB_SLAVE = 1,
+ SMB_MASTER
+};
+
+/*
+ * External SMB Interface driver xfer indication values, which indicate status
+ * of the bus.
+ */
+enum smb_state_ind {
+ SMB_NO_STATUS_IND = 0,
+ SMB_SLAVE_RCV_IND = 1,
+ SMB_SLAVE_XMIT_IND = 2,
+ SMB_SLAVE_XMIT_MISSING_DATA_IND = 3,
+ SMB_SLAVE_RESTART_IND = 4,
+ SMB_SLAVE_DONE_IND = 5,
+ SMB_MASTER_DONE_IND = 6,
+ SMB_NACK_IND = 8,
+ SMB_BUS_ERR_IND = 9,
+ SMB_WAKE_UP_IND = 10,
+ SMB_BLOCK_BYTES_ERR_IND = 12,
+ SMB_SLAVE_RCV_MISSING_DATA_IND = 14,
+};
+
+// SMBus Operation type values
+enum smb_oper {
+ SMB_NO_OPER = 0,
+ SMB_WRITE_OPER = 1,
+ SMB_READ_OPER = 2
+};
+
+// SMBus Bank (FIFO mode)
+enum smb_bank {
+ SMB_BANK_0 = 0,
+ SMB_BANK_1 = 1
+};
+
+// Internal SMB states values (for the SMB module state machine).
+enum smb_state {
+ SMB_DISABLE = 0,
+ SMB_IDLE,
+ SMB_MASTER_START,
+ SMB_SLAVE_MATCH,
+ SMB_OPER_STARTED,
+ SMB_STOP_PENDING
+};
+
+// Module supports setting multiple own slave addresses
+enum smb_addr {
+ SMB_SLAVE_ADDR1 = 0,
+ SMB_SLAVE_ADDR2,
+ SMB_SLAVE_ADDR3,
+ SMB_SLAVE_ADDR4,
+ SMB_SLAVE_ADDR5,
+ SMB_SLAVE_ADDR6,
+ SMB_SLAVE_ADDR7,
+ SMB_SLAVE_ADDR8,
+ SMB_SLAVE_ADDR9,
+ SMB_SLAVE_ADDR10,
+ SMB_GC_ADDR,
+ SMB_ARP_ADDR
+};
+
+// global regs
+static struct regmap *gcr_regmap;
+static struct regmap *clk_regmap;
+
+#define NPCM_I2CSEGCTL 0xE4
+#define I2CSEGCTL_VAL 0x0333F000
+
+// Common regs
+#define NPCM_SMBSDA 0x000
+#define NPCM_SMBST 0x002
+#define NPCM_SMBCST 0x004
+#define NPCM_SMBCTL1 0x006
+#define NPCM_SMBADDR1 0x008
+#define NPCM_SMBCTL2 0x00A
+#define NPCM_SMBADDR2 0x00C
+#define NPCM_SMBCTL3 0x00E
+#define NPCM_SMBCST2 0x018
+#define NPCM_SMBCST3 0x019
+#define SMB_VER 0x01F
+
+// BANK 0 regs
+#define NPCM_SMBADDR3 0x010
+#define NPCM_SMBADDR7 0x011
+#define NPCM_SMBADDR4 0x012
+#define NPCM_SMBADDR8 0x013
+#define NPCM_SMBADDR5 0x014
+#define NPCM_SMBADDR9 0x015
+#define NPCM_SMBADDR6 0x016
+#define NPCM_SMBADDR10 0x017
+
+// SMBADDR array: because the addr regs are sprinkled all over the address space
+const int NPCM_SMBADDR[10] = {NPCM_SMBADDR1, NPCM_SMBADDR2, NPCM_SMBADDR3,
+ NPCM_SMBADDR4, NPCM_SMBADDR5, NPCM_SMBADDR6,
+ NPCM_SMBADDR7, NPCM_SMBADDR8, NPCM_SMBADDR9,
+ NPCM_SMBADDR10};
+
+#define NPCM_SMBCTL4 0x01A
+#define NPCM_SMBCTL5 0x01B
+#define NPCM_SMBSCLLT 0x01C // SCL Low Time
+#define NPCM_SMBFIF_CTL 0x01D // FIFO Control
+#define NPCM_SMBSCLHT 0x01E // SCL High Time
+
+// BANK 1 regs
+#define NPCM_SMBFIF_CTS 0x010 // Both FIFOs Control and status
+#define NPCM_SMBTXF_CTL 0x012 // Tx-FIFO Control
+#define NPCM_SMBT_OUT 0x014 // Bus T.O.
+#define NPCM_SMBPEC 0x016 // PEC Data
+#define NPCM_SMBTXF_STS 0x01A // Tx-FIFO Status
+#define NPCM_SMBRXF_STS 0x01C // Rx-FIFO Status
+#define NPCM_SMBRXF_CTL 0x01E // Rx-FIFO Control
+
+// NPCM_SMBST reg fields
+#define NPCM_SMBST_XMIT BIT(0)
+#define NPCM_SMBST_MASTER BIT(1)
+#define NPCM_SMBST_NMATCH BIT(2)
+#define NPCM_SMBST_STASTR BIT(3)
+#define NPCM_SMBST_NEGACK BIT(4)
+#define NPCM_SMBST_BER BIT(5)
+#define NPCM_SMBST_SDAST BIT(6)
+#define NPCM_SMBST_SLVSTP BIT(7)
+
+// NPCM_SMBCST reg fields
+#define NPCM_SMBCST_BUSY BIT(0)
+#define NPCM_SMBCST_BB BIT(1)
+#define NPCM_SMBCST_MATCH BIT(2)
+#define NPCM_SMBCST_GCMATCH BIT(3)
+#define NPCM_SMBCST_TSDA BIT(4)
+#define NPCM_SMBCST_TGSCL BIT(5)
+#define NPCM_SMBCST_MATCHAF BIT(6)
+#define NPCM_SMBCST_ARPMATCH BIT(7)
+
+// NPCM_SMBCTL1 reg fields
+#define NPCM_SMBCTL1_START BIT(0)
+#define NPCM_SMBCTL1_STOP BIT(1)
+#define NPCM_SMBCTL1_INTEN BIT(2)
+#define NPCM_SMBCTL1_EOBINTE BIT(3)
+#define NPCM_SMBCTL1_ACK BIT(4)
+#define NPCM_SMBCTL1_GCMEN BIT(5)
+#define NPCM_SMBCTL1_NMINTE BIT(6)
+#define NPCM_SMBCTL1_STASTRE BIT(7)
+
+// RW1S fields (inside a RW reg):
+#define NPCM_SMBCTL1_RWS_FIELDS (NPCM_SMBCTL1_START | NPCM_SMBCTL1_STOP | \
+ NPCM_SMBCTL1_ACK)
+// NPCM_SMBADDR reg fields
+#define NPCM_SMBADDR_A GENMASK(6, 0)
+#define NPCM_SMBADDR_SAEN BIT(7)
+
+// NPCM_SMBCTL2 reg fields
+#define SMBCTL2_ENABLE BIT(0)
+#define SMBCTL2_SCLFRQ6_0 GENMASK(7, 1)
+
+// NPCM_SMBCTL3 reg fields
+#define SMBCTL3_SCLFRQ8_7 GENMASK(1, 0)
+#define SMBCTL3_ARPMEN BIT(2)
+#define SMBCTL3_IDL_START BIT(3)
+#define SMBCTL3_400K_MODE BIT(4)
+#define SMBCTL3_BNK_SEL BIT(5)
+#define SMBCTL3_SDA_LVL BIT(6)
+#define SMBCTL3_SCL_LVL BIT(7)
+
+// NPCM_SMBCST2 reg fields
+#define NPCM_SMBCST2_MATCHA1F BIT(0)
+#define NPCM_SMBCST2_MATCHA2F BIT(1)
+#define NPCM_SMBCST2_MATCHA3F BIT(2)
+#define NPCM_SMBCST2_MATCHA4F BIT(3)
+#define NPCM_SMBCST2_MATCHA5F BIT(4)
+#define NPCM_SMBCST2_MATCHA6F BIT(5)
+#define NPCM_SMBCST2_MATCHA7F BIT(5)
+#define NPCM_SMBCST2_INTSTS BIT(7)
+
+// NPCM_SMBCST3 reg fields
+#define NPCM_SMBCST3_MATCHA8F BIT(0)
+#define NPCM_SMBCST3_MATCHA9F BIT(1)
+#define NPCM_SMBCST3_MATCHA10F BIT(2)
+#define NPCM_SMBCST3_EO_BUSY BIT(7)
+
+// NPCM_SMBCTL4 reg fields
+#define SMBCTL4_HLDT GENMASK(5, 0)
+#define SMBCTL4_LVL_WE BIT(7)
+
+// NPCM_SMBCTL5 reg fields
+#define SMBCTL5_DBNCT GENMASK(3, 0)
+
+// NPCM_SMBFIF_CTS reg fields
+#define NPCM_SMBFIF_CTS_RXF_TXE BIT(1)
+#define NPCM_SMBFIF_CTS_RFTE_IE BIT(3)
+#define NPCM_SMBFIF_CTS_CLR_FIFO BIT(6)
+#define NPCM_SMBFIF_CTS_SLVRSTR BIT(7)
+
+// NPCM_SMBTXF_CTL reg fields
+#define NPCM_SMBTXF_CTL_TX_THR GENMASK(4, 0)
+#define NPCM_SMBTXF_CTL_THR_TXIE BIT(6)
+
+// NPCM_SMBT_OUT reg fields
+#define NPCM_SMBT_OUT_TO_CKDIV GENMASK(5, 0)
+#define NPCM_SMBT_OUT_T_OUTIE BIT(6)
+#define NPCM_SMBT_OUT_T_OUTST BIT(7)
+
+// NPCM_SMBTXF_STS reg fields
+#define NPCM_SMBTXF_STS_TX_BYTES GENMASK(4, 0)
+#define NPCM_SMBTXF_STS_TX_THST BIT(6)
+
+// NPCM_SMBRXF_STS reg fields
+#define NPCM_SMBRXF_STS_RX_BYTES GENMASK(4, 0)
+#define NPCM_SMBRXF_STS_RX_THST BIT(6)
+
+// NPCM_SMBFIF_CTL reg fields
+#define NPCM_SMBFIF_CTL_FIFO_EN BIT(4)
+
+// NPCM_SMBRXF_CTL reg fields
+#define NPCM_SMBRXF_CTL_RX_THR GENMASK(4, 0)
+#define NPCM_SMBRXF_CTL_LAST_PEC BIT(5)
+#define NPCM_SMBRXF_CTL_THR_RXIE BIT(6)
+
+#define SMBUS_FIFO_SIZE 16
+
+// SMB_VER reg fields
+#define SMB_VER_VERSION GENMASK(6, 0)
+#define SMB_VER_FIFO_EN BIT(7)
+
+// stall/stuck timeout
+const unsigned int DEFAULT_STALL_COUNT = 25;
+
+// retries in a loop for master abort
+const unsigned int RETRIES_NUM = 10000;
+
+// SMBus spec. values in KHZ
+const unsigned int SMBUS_FREQ_MIN = 10;
+const unsigned int SMBUS_FREQ_MAX = 1000;
+const unsigned int SMBUS_FREQ_100KHZ = 100;
+const unsigned int SMBUS_FREQ_400KHZ = 400;
+const unsigned int SMBUS_FREQ_1MHZ = 1000;
+
+// SCLFRQ min/max field values
+const unsigned int SCLFRQ_MIN = 10;
+const unsigned int SCLFRQ_MAX = 511;
+
+// SCLFRQ field position
+#define SCLFRQ_0_TO_6 GENMASK(6, 0)
+#define SCLFRQ_7_TO_8 GENMASK(8, 7)
+
+const unsigned int SMB_NUM_OF_ADDR = 10;
+
+#define NPCM_I2C_EVENT_START BIT(0)
+#define NPCM_I2C_EVENT_STOP BIT(1)
+#define NPCM_I2C_EVENT_ABORT BIT(2)
+#define NPCM_I2C_EVENT_WRITE BIT(3)
+
+#define NPCM_I2C_EVENT_READ BIT(4)
+#define NPCM_I2C_EVENT_BER BIT(5)
+#define NPCM_I2C_EVENT_NACK BIT(6)
+#define NPCM_I2C_EVENT_TO BIT(7)
+
+#define NPCM_I2C_EVENT_EOB BIT(8)
+#define NPCM_I2C_EVENT_STALL BIT(9)
+#define NPCM_I2C_EVENT_CB BIT(10)
+#define NPCM_I2C_EVENT_DONE BIT(11)
+
+#define NPCM_I2C_EVENT_READ1 BIT(12)
+#define NPCM_I2C_EVENT_READ2 BIT(13)
+#define NPCM_I2C_EVENT_READ3 BIT(14)
+#define NPCM_I2C_EVENT_READ4 BIT(15)
+
+#define NPCM_I2C_EVENT_NMATCH_SLV BIT(16)
+#define NPCM_I2C_EVENT_NMATCH_MSTR BIT(17)
+#define NPCM_I2C_EVENT_BER_SLV BIT(18)
+
+#define NPCM_I2C_EVENT_LOG(event) (bus->event_log |= event)
+
+// Status of one SMBus module
+struct npcm_i2c {
+ struct i2c_adapter adap;
+ struct device *dev;
+ unsigned char __iomem *reg;
+ spinlock_t lock; /* IRQ synchronization */
+ struct completion cmd_complete;
+ int irq;
+ int cmd_err;
+ struct i2c_msg *msgs;
+ int msgs_num;
+ int num;
+ u32 apb_clk;
+ struct i2c_bus_recovery_info rinfo;
+ enum smb_state state;
+ enum smb_oper operation;
+ enum smb_mode master_or_slave;
+ enum smb_state_ind stop_ind;
+ u8 dest_addr;
+ u8 *rd_buf;
+ u16 rd_size;
+ u16 rd_ind;
+ u8 *wr_buf;
+ u16 wr_size;
+ u16 wr_ind;
+ bool fifo_use;
+
+ // PEC bit mask per slave address.
+ // 1: use PEC for this address,
+ // 0: do not use PEC for this address
+ u16 PEC_mask;
+ bool PEC_use;
+ bool read_block_use;
+ u8 int_cnt;
+ u32 event_log;
+ u32 event_log_prev;
+ u32 clk_period_us;
+ unsigned long int_time_stamp;
+ unsigned long bus_freq; // in kHz
+ u32 xmits;
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ u8 own_slave_addr;
+ struct i2c_client *slave;
+
+ // currently I2C slave IF only supports single byte operations.
+ // in order to utilyze the npcm HW FIFO, the driver will ask for 16bytes
+ // at a time, pack them in buffer, and then transmit them all together
+ // to the FIFO and onward to the bus .
+ // NACK on read will be once reached to bus->adap->quirks->max_read_len
+ // sending a NACK whever the backend requests for it is not supported.
+
+ // This module can be master and slave at the same time. separate ptrs
+ // and counters:
+ int slv_rd_size;
+ int slv_rd_ind;
+ int slv_wr_size;
+ int slv_wr_ind;
+ u8 slv_rd_buf[SMBUS_FIFO_SIZE];
+ u8 slv_wr_buf[SMBUS_FIFO_SIZE];
+#endif
+};
+
+static inline void npcm_smb_select_bank(struct npcm_i2c *bus,
+ enum smb_bank bank)
+{
+ if (bank == SMB_BANK_0)
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL3) & ~SMBCTL3_BNK_SEL,
+ bus->reg + NPCM_SMBCTL3);
+ else
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL3) | SMBCTL3_BNK_SEL,
+ bus->reg + NPCM_SMBCTL3);
+}
+
+static void npcm_smb_init_params(struct npcm_i2c *bus)
+{
+ bus->stop_ind = SMB_NO_STATUS_IND;
+ bus->rd_size = 0;
+ bus->wr_size = 0;
+ bus->rd_ind = 0;
+ bus->wr_ind = 0;
+ bus->int_cnt = 0;
+ bus->event_log_prev = bus->event_log;
+ bus->event_log = 0;
+ bus->read_block_use = false;
+ bus->int_time_stamp = 0;
+ bus->PEC_use = false;
+ bus->PEC_mask = 0;
+ if (bus->slave)
+ bus->master_or_slave = SMB_SLAVE;
+}
+
+static inline void npcm_smb_wr_byte(struct npcm_i2c *bus, u8 data)
+{
+ iowrite8(data, bus->reg + NPCM_SMBSDA);
+}
+
+static inline void npcm_smb_rd_byte(struct npcm_i2c *bus, u8 *data)
+{
+ *data = ioread8(bus->reg + NPCM_SMBSDA);
+}
+
+static inline u16 npcm_smb_get_index(struct npcm_i2c *bus)
+{
+ u16 index = 0;
+
+ if (bus->operation == SMB_READ_OPER)
+ index = bus->rd_ind;
+ else if (bus->operation == SMB_WRITE_OPER)
+ index = bus->wr_ind;
+
+ return index;
+}
+
+// quick protocol (just address):
+static inline bool npcm_smb_is_quick(struct npcm_i2c *bus)
+{
+ if (bus->wr_size == 0 && bus->rd_size == 0)
+ return true;
+ return false;
+}
+
+static void npcm_smb_disable(struct npcm_i2c *bus)
+{
+ int i;
+
+ // select bank 0 for SMB addresses
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ // Slave addresses removal
+ for (i = SMB_SLAVE_ADDR1; i < SMB_NUM_OF_ADDR; i++)
+ iowrite8(0, bus->reg + NPCM_SMBADDR[i]);
+
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ // Disable module.
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL2) & ~SMBCTL2_ENABLE,
+ bus->reg + NPCM_SMBCTL2);
+
+ bus->state = SMB_DISABLE;
+}
+
+static void npcm_smb_enable(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL2) | SMBCTL2_ENABLE),
+ bus->reg + NPCM_SMBCTL2);
+
+ bus->state = SMB_IDLE;
+}
+
+static bool npcm_smb_wait_for_bus_free(struct npcm_i2c *bus, bool may_sleep)
+{
+ int cnt = 0;
+ int max_count = 2; /* wait for 2 ms */
+
+ if (may_sleep)
+ might_sleep();
+ else
+ max_count = max_count * 100; /* since each delay is 10 us */
+
+ while (ioread8(bus->reg + NPCM_SMBCST) & NPCM_SMBCST_BUSY) {
+ if (cnt < max_count) {
+ if (may_sleep)
+ msleep_interruptible(1);
+ else
+ udelay(10);
+ cnt++;
+
+ } else {
+ bus->cmd_err = -EAGAIN;
+ return false;
+ }
+ }
+ return true;
+}
+
+// enable\disable end of busy (EOB) interrupt
+static inline void npcm_smb_eob_int(struct npcm_i2c *bus, bool enable)
+{
+ // Clear EO_BUSY pending bit:
+ iowrite8(ioread8(bus->reg + NPCM_SMBCST3) | NPCM_SMBCST3_EO_BUSY,
+ bus->reg + NPCM_SMBCST3);
+
+ if (enable) {
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) |
+ NPCM_SMBCTL1_EOBINTE) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ } else {
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_EOBINTE & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ }
+}
+
+static inline bool npcm_smb_tx_fifo_empty(struct npcm_i2c *bus)
+{
+ u8 tx_fifo_sts = ioread8(bus->reg + NPCM_SMBTXF_STS);
+
+ // check if TX FIFO is not empty
+ if ((tx_fifo_sts & NPCM_SMBTXF_STS_TX_BYTES) == 0)
+ return false;
+
+ // check if TX FIFO status bit is set:
+ return (bool)FIELD_GET(NPCM_SMBTXF_STS_TX_THST, tx_fifo_sts);
+}
+
+static inline bool npcm_smb_rx_fifo_full(struct npcm_i2c *bus)
+{
+ u8 rx_fifo_sts = ioread8(bus->reg + NPCM_SMBRXF_STS);
+
+ // check if RX FIFO is not empty:
+ if ((rx_fifo_sts & NPCM_SMBRXF_STS_RX_BYTES) == 0)
+ return false;
+
+ // check if rx fifo full status is set:
+ return (bool)FIELD_GET(NPCM_SMBRXF_STS_RX_THST, rx_fifo_sts);
+}
+
+static inline void npcm_smb_clear_fifo_int(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_SMBFIF_CTS) &
+ NPCM_SMBFIF_CTS_SLVRSTR) |
+ NPCM_SMBFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_SMBFIF_CTS);
+}
+
+static inline void npcm_smb_clear_tx_fifo(struct npcm_i2c *bus)
+{
+ iowrite8(ioread8(bus->reg + NPCM_SMBTXF_STS) | NPCM_SMBTXF_STS_TX_THST,
+ bus->reg + NPCM_SMBTXF_STS);
+}
+
+static inline void npcm_smb_clear_rx_fifo(struct npcm_i2c *bus)
+{
+ iowrite8(ioread8(bus->reg + NPCM_SMBRXF_STS) | NPCM_SMBRXF_STS_RX_THST,
+ bus->reg + NPCM_SMBRXF_STS);
+}
+
+static void npcm_smb_int_enable(struct npcm_i2c *bus, bool enable)
+{
+ if (enable)
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) |
+ NPCM_SMBCTL1_INTEN) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_INTEN) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static inline void npcm_smb_master_start(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_START);
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_START) &
+ ~(NPCM_SMBCTL1_STOP | NPCM_SMBCTL1_ACK),
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static inline void npcm_smb_master_stop(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STOP);
+
+ // override HW issue: SMBus may fail to supply stop condition in Master
+ // Write operation.
+ // Need to delay at least 5 us from the last int, before issueing a stop
+ udelay(10);
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_STOP) &
+ ~(NPCM_SMBCTL1_START | NPCM_SMBCTL1_ACK),
+ bus->reg + NPCM_SMBCTL1);
+
+ if (bus->fifo_use) {
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ if (bus->operation == SMB_READ_OPER)
+ npcm_smb_clear_rx_fifo(bus);
+ else
+ npcm_smb_clear_tx_fifo(bus);
+
+ npcm_smb_clear_fifo_int(bus);
+
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ }
+}
+
+static inline void npcm_smb_stall_after_start(struct npcm_i2c *bus, bool stall)
+{
+ if (stall)
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) |
+ NPCM_SMBCTL1_STASTRE) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_STASTRE) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static inline void npcm_smb_nack(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_ACK) &
+ ~(NPCM_SMBCTL1_STOP | NPCM_SMBCTL1_START),
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static int npcm_smb_slave_enable_l(struct npcm_i2c *bus,
+ enum smb_addr addr_type, u8 addr,
+ bool enable);
+
+static void npcm_smb_reset(struct npcm_i2c *bus)
+{
+ // Save NPCM_SMBCTL1 relevant bits. It is being cleared when the
+ // module is disabled
+ u8 smbctl1;
+
+ smbctl1 = ioread8(bus->reg + NPCM_SMBCTL1);
+
+ // Disable the SMB module
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL2) & ~SMBCTL2_ENABLE),
+ bus->reg + NPCM_SMBCTL2);
+
+ // Enable the SMB module
+ npcm_smb_enable(bus);
+
+ // Restore NPCM_SMBCTL1 status
+ iowrite8(smbctl1 & ~NPCM_SMBCTL1_RWS_FIELDS, bus->reg + NPCM_SMBCTL1);
+
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST);
+
+ iowrite8(0xFF, bus->reg + NPCM_SMBST);
+
+ // Clear EOB bit
+ iowrite8(NPCM_SMBCST3_EO_BUSY, bus->reg + NPCM_SMBCST3);
+
+ // Clear all fifo bits:
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, bus->reg + NPCM_SMBFIF_CTS);
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ npcm_smb_slave_enable_l(bus, SMB_SLAVE_ADDR1, bus->slave->addr,
+ true);
+ }
+#endif
+
+ bus->state = SMB_IDLE;
+}
+
+static inline bool npcm_smb_is_master(struct npcm_i2c *bus)
+{
+ return (bool)FIELD_GET(NPCM_SMBST_MASTER,
+ ioread8(bus->reg + NPCM_SMBST));
+}
+
+static void npcm_smb_callback(struct npcm_i2c *bus,
+ enum smb_state_ind op_status, u16 info)
+{
+ struct i2c_msg *msgs = bus->msgs;
+ int msgs_num = bus->msgs_num;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_CB);
+
+ if (!msgs)
+ return;
+
+ if (completion_done(&bus->cmd_complete) == true)
+ return;
+
+ switch (op_status) {
+ case SMB_MASTER_DONE_IND:
+ bus->cmd_err = bus->msgs_num;
+ // fall through:
+ case SMB_BLOCK_BYTES_ERR_IND:
+ // Master transaction finished and all transmit bytes were sent
+ if (bus->msgs) {
+ if (msgs[0].flags & I2C_M_RD)
+ msgs[0].len = info;
+ else if (msgs_num == 2 &&
+ msgs[1].flags & I2C_M_RD)
+ msgs[1].len = info;
+ }
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_DONE);
+
+ if (completion_done(&bus->cmd_complete) == false)
+ complete(&bus->cmd_complete);
+ break;
+
+ case SMB_NACK_IND:
+ // MASTER transmit got a NACK before tx all bytes
+ // info: number of transmitted bytes
+ bus->cmd_err = -ENXIO;
+ if (bus->master_or_slave == SMB_MASTER)
+ complete(&bus->cmd_complete);
+
+ break;
+ case SMB_BUS_ERR_IND:
+ // Bus error
+ bus->cmd_err = -EAGAIN;
+ if (bus->master_or_slave == SMB_MASTER)
+ complete(&bus->cmd_complete);
+
+ break;
+ case SMB_WAKE_UP_IND:
+ // SMBus wake up
+ break;
+ default:
+ break;
+ }
+
+ bus->operation = SMB_NO_OPER;
+ if (bus->slave)
+ bus->master_or_slave = SMB_SLAVE;
+}
+
+static u32 npcm_smb_get_fifo_fullness(struct npcm_i2c *bus)
+{
+ if (bus->operation == SMB_WRITE_OPER)
+ return FIELD_GET(NPCM_SMBTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_SMBTXF_STS));
+ else if (bus->operation == SMB_READ_OPER)
+ return FIELD_GET(NPCM_SMBRXF_STS_RX_BYTES,
+ ioread8(bus->reg + NPCM_SMBRXF_STS));
+ return 0;
+}
+
+static void npcm_smb_write_to_fifo_master(struct npcm_i2c *bus,
+ u16 max_bytes_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ if (max_bytes_to_send == 0)
+ return;
+ while ((max_bytes_to_send--) && (SMBUS_FIFO_SIZE -
+ npcm_smb_get_fifo_fullness(bus))) {
+ if (bus->wr_ind < bus->wr_size)
+ npcm_smb_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
+ else
+ npcm_smb_wr_byte(bus, 0xFF);
+ }
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void npcm_smb_write_to_fifo_slave(struct npcm_i2c *bus,
+ u16 max_bytes_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ npcm_smb_clear_fifo_int(bus);
+ npcm_smb_clear_tx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+
+ if (max_bytes_to_send == 0)
+ return;
+
+ while ((max_bytes_to_send--) && (SMBUS_FIFO_SIZE -
+ npcm_smb_get_fifo_fullness(bus))) {
+ if (bus->slv_wr_size > 0) {
+ npcm_smb_wr_byte(bus,
+ bus->slv_wr_buf[bus->slv_wr_ind %
+ SMBUS_FIFO_SIZE]);
+ bus->slv_wr_ind = (bus->slv_wr_ind + 1) %
+ SMBUS_FIFO_SIZE;
+ bus->slv_wr_size--; // size indicates the # of bytes in
+ // the SW FIFO, not HW.
+ } else {
+ break;
+ }
+ }
+}
+#endif
+
+// configure the FIFO before using it. If nread is -1 RX FIFO will not be
+// configured. same for nwrite
+static void npcm_smb_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
+{
+ u8 rxf_ctl = 0;
+
+ if (!bus->fifo_use)
+ return;
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ npcm_smb_clear_tx_fifo(bus);
+ npcm_smb_clear_rx_fifo(bus);
+
+ // configure RX FIFO
+ if (nread > 0) {
+ rxf_ctl = min_t(u16, (u16)nread, (u16)SMBUS_FIFO_SIZE);
+
+ // set LAST bit. if LAST is set enxt FIFO packet is nacked
+ // regular read of less then buffer size:
+ if (nread <= SMBUS_FIFO_SIZE)
+ rxf_ctl |= NPCM_SMBRXF_CTL_LAST_PEC;
+ // if we are about to read the first byte in blk rd mode,
+ // don't NACK it. BTW, if slave return zero size HW can't NACK
+ // it immidiattly, it will read extra byte and then NACK.
+ if (bus->rd_ind == 0 && bus->read_block_use) {
+ // set fifo to read one byte, no last:
+ rxf_ctl = 1;
+ }
+
+ // set fifo size:
+ iowrite8(rxf_ctl, bus->reg + NPCM_SMBRXF_CTL);
+ }
+
+ // configure TX FIFO
+ if (nwrite > 0) {
+ if (nwrite > SMBUS_FIFO_SIZE)
+ // data to send is more then FIFO size.
+ // Configure the FIFO int to be after of FIFO is cleared
+ iowrite8(SMBUS_FIFO_SIZE, bus->reg + NPCM_SMBTXF_CTL);
+ else
+ iowrite8(nwrite, bus->reg + NPCM_SMBTXF_CTL);
+
+ npcm_smb_clear_tx_fifo(bus);
+ }
+}
+
+static void npcm_smb_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
+{
+ u8 data;
+
+ while (bytes_in_fifo--) {
+ npcm_smb_rd_byte(bus, &data);
+
+ if (bus->master_or_slave == SMB_MASTER) {
+ if (bus->rd_ind < bus->rd_size)
+ bus->rd_buf[bus->rd_ind++] = data;
+ } else { // SMB_SLAVE:
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ bus->slv_rd_buf[bus->slv_rd_ind %
+ SMBUS_FIFO_SIZE] = data;
+ bus->slv_rd_ind++;
+ if (bus->slv_rd_ind == 1 && bus->read_block_use)
+ // 1st byte is length in block protocol
+ bus->slv_rd_size = data +
+ (u8)bus->PEC_use +
+ (u8)bus->read_block_use;
+ }
+#endif
+ }
+ }
+}
+
+static int npcm_smb_master_abort(struct npcm_i2c *bus)
+{
+ int ret = 0;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_ABORT);
+
+ // Only current master is allowed to issue Stop Condition
+ if (npcm_smb_is_master(bus)) {
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_SMBST_BER | NPCM_SMBST_NEGACK | NPCM_SMBST_STASTR,
+ bus->reg + NPCM_SMBST);
+ }
+
+ return ret;
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id);
+
+static int npcm_smb_slave_enable_l(struct npcm_i2c *bus,
+ enum smb_addr addr_type, u8 addr,
+ bool enable)
+{
+ u8 slave_addr_reg = FIELD_PREP(NPCM_SMBADDR_A, addr) |
+ FIELD_PREP(NPCM_SMBADDR_SAEN, enable);
+
+ if (addr_type == SMB_GC_ADDR) {
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_GCMEN) |
+ FIELD_PREP(NPCM_SMBCTL1_GCMEN, enable),
+ bus->reg + NPCM_SMBCTL1);
+ return 0;
+ }
+ if (addr_type == SMB_ARP_ADDR) {
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL3) &
+ ~SMBCTL3_ARPMEN) |
+ FIELD_PREP(SMBCTL3_ARPMEN, enable),
+ bus->reg + NPCM_SMBCTL3);
+ return 0;
+ }
+ if (addr_type >= SMB_ARP_ADDR)
+ return -EFAULT;
+
+ // select bank 0 for address 3 to 10
+ if (addr_type > SMB_SLAVE_ADDR2)
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ // Set and enable the address
+ iowrite8(slave_addr_reg, bus->reg + NPCM_SMBADDR[(int)addr_type]);
+
+ // enable interrupt on slave match:
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) &
+ ~NPCM_SMBCTL1_RWS_FIELDS, bus->reg + NPCM_SMBCTL1);
+
+ if (addr_type > SMB_SLAVE_ADDR2)
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ return 0;
+}
+
+static u8 npcm_smb_get_slave_addr(struct npcm_i2c *bus,
+ enum smb_addr addr_type)
+{
+ u8 slave_add;
+
+ // select bank 0 for address 3 to 10
+ if (addr_type > SMB_SLAVE_ADDR2)
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ slave_add = ioread8(bus->reg + NPCM_SMBADDR[(int)addr_type]);
+
+ if (addr_type > SMB_SLAVE_ADDR2)
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ return slave_add;
+}
+
+static int npcm_smb_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add)
+{
+ int i;
+
+ slave_add |= 0x80; //Set the enable bit
+
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ for (i = SMB_SLAVE_ADDR1; i < SMB_NUM_OF_ADDR; i++) {
+ if (ioread8(bus->reg + NPCM_SMBADDR[i]) == slave_add)
+ iowrite8(0, bus->reg + NPCM_SMBADDR[i]);
+ }
+
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ return 0;
+}
+
+static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
+{
+ u8 value = 0;
+ int ret = bus->slv_wr_ind;
+ int i;
+
+ // fill a cyclic buffer
+ for (i = 0; i < SMBUS_FIFO_SIZE; i++) {
+ if (bus->slv_wr_size >= SMBUS_FIFO_SIZE)
+ break;
+ i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value);
+ bus->slv_wr_buf[(bus->slv_wr_ind + bus->slv_wr_size) %
+ SMBUS_FIFO_SIZE] = value;
+ bus->slv_wr_size++;
+ i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value);
+ }
+ return SMBUS_FIFO_SIZE - ret;
+}
+
+static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus)
+{
+ int i;
+
+ for (i = 0; i < bus->slv_rd_ind; i++)
+ i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_RECEIVED,
+ &bus->slv_rd_buf[i]);
+
+ // once we send bytes up, need to reset the counter of the wr buf
+ // got data from master (new offset in device), ignore wr fifo:
+ if (bus->slv_rd_ind) {
+ bus->slv_wr_size = 0;
+ bus->slv_wr_ind = 0;
+ }
+
+ bus->slv_rd_ind = 0;
+ bus->slv_rd_size = bus->adap.quirks->max_read_len;
+
+ npcm_smb_clear_fifo_int(bus);
+ npcm_smb_clear_rx_fifo(bus);
+}
+
+static bool npcm_smb_slave_receive(struct npcm_i2c *bus, u16 nread,
+ u8 *read_data)
+{
+ bus->state = SMB_OPER_STARTED;
+ bus->operation = SMB_READ_OPER;
+ bus->slv_rd_size = nread;
+ bus->slv_rd_ind = 0;
+
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ iowrite8(SMBUS_FIFO_SIZE, bus->reg + NPCM_SMBRXF_CTL);
+
+ npcm_smb_clear_tx_fifo(bus);
+ npcm_smb_clear_rx_fifo(bus);
+
+ return true;
+}
+
+static bool npcm_smb_slave_xmit(struct npcm_i2c *bus, u16 nwrite,
+ u8 *write_data)
+{
+ if (nwrite == 0)
+ return false;
+
+ bus->state = SMB_OPER_STARTED;
+ bus->operation = SMB_WRITE_OPER;
+
+ // get the next buffer
+ npcm_i2c_slave_get_wr_buf(bus);
+
+ if (nwrite > 0)
+ npcm_smb_write_to_fifo_slave(bus, nwrite);
+
+ return true;
+}
+
+// currently slave IF only supports single byte operations.
+// in order to utilyze the npcm HW FIFO, the driver will ask for 16 bytes
+// at a time, pack them in buffer, and then transmit them all together
+// to the FIFO and onward to the bus.
+// NACK on read will be once reached to bus->adap->quirks->max_read_len.
+// sending a NACK wherever the backend requests for it is not supported.
+// the next two functions allow reading to local buffer before writing it all
+// to the HW FIFO.
+// ret val: number of bytes read form the IF:
+
+static int npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus)
+{
+ int left_in_fifo = FIELD_GET(NPCM_SMBTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_SMBTXF_STS));
+
+ if (left_in_fifo >= SMBUS_FIFO_SIZE)
+ return left_in_fifo;
+
+ if (bus->slv_wr_size >= SMBUS_FIFO_SIZE)
+ return left_in_fifo; // fifo already full
+
+ // update the wr fifo ind, back to the untransmitted bytes:
+ bus->slv_wr_ind = bus->slv_wr_ind - left_in_fifo;
+ bus->slv_wr_size = bus->slv_wr_size + left_in_fifo;
+
+ if (bus->slv_wr_ind < 0)
+ bus->slv_wr_ind += SMBUS_FIFO_SIZE;
+
+ return left_in_fifo;
+}
+
+static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus)
+{
+ if (FIELD_GET(NPCM_SMBST_XMIT, ioread8(bus->reg + NPCM_SMBST))) {
+ // Slave got an address match with direction bit 1 so
+ // it should transmit data
+ // Write till the master will NACK
+ bus->operation = SMB_WRITE_OPER;
+ npcm_smb_slave_xmit(bus,
+ bus->adap.quirks->max_write_len,
+ bus->slv_wr_buf);
+ } else {
+ // Slave got an address match with direction bit 0
+ // so it should receive data.
+ // this module does not support saying no to bytes.
+ // it will always ACK.
+ bus->operation = SMB_READ_OPER;
+ npcm_smb_read_from_fifo(bus, npcm_smb_get_fifo_fullness(bus));
+ bus->stop_ind = SMB_SLAVE_RCV_IND;
+ npcm_i2c_slave_send_rd_buf(bus);
+ npcm_smb_slave_receive(bus,
+ bus->adap.quirks->max_read_len,
+ bus->slv_rd_buf);
+ }
+}
+
+static irqreturn_t npcm_smb_int_slave_handler(struct npcm_i2c *bus)
+{
+ irqreturn_t ret = IRQ_NONE;
+ u8 smbst = ioread8(bus->reg + NPCM_SMBST);
+ // Slave: A NACK has occurred
+ if (FIELD_GET(NPCM_SMBST_NEGACK, smbst)) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK);
+ bus->stop_ind = SMB_NACK_IND;
+ npcm_i2c_slave_wr_buf_sync(bus);
+ if (bus->fifo_use)
+ // clear the FIFO
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+
+ // In slave write, NACK is OK, otherwise it is a problem
+ bus->stop_ind = SMB_NO_STATUS_IND;
+ bus->operation = SMB_NO_OPER;
+ bus->own_slave_addr = 0xFF;
+
+ // Slave has to wait for SMB_STOP to decide this is the end
+ // of the transaction.
+ // Therefore transaction is not yet considered as done
+ iowrite8(NPCM_SMBST_NEGACK, bus->reg + NPCM_SMBST);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // Slave mode: a Bus Error (BER) has been identified
+ if (FIELD_GET(NPCM_SMBST_BER, smbst)) {
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_BER_SLV);
+ bus->stop_ind = SMB_BUS_ERR_IND;
+
+ // wait for bus busy before clear fifo
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO, bus->reg + NPCM_SMBFIF_CTS);
+
+ bus->state = SMB_IDLE;
+
+ // in BER case we might get 2 interrupts: one for slave one for
+ // master ( for a channel which is master\slave switching)
+ if (completion_done(&bus->cmd_complete) == false) {
+ bus->cmd_err = -EIO;
+ complete(&bus->cmd_complete);
+ }
+ bus->own_slave_addr = 0xFF;
+ iowrite8(NPCM_SMBST_BER, bus->reg + NPCM_SMBST);
+ ret = IRQ_HANDLED;
+ }
+
+ // A Slave Stop Condition has been identified
+ if (FIELD_GET(NPCM_SMBST_SLVSTP, smbst)) {
+ int bytes_in_fifo = npcm_smb_get_fifo_fullness(bus);
+
+ bus->stop_ind = SMB_SLAVE_DONE_IND;
+
+ if (bus->operation == SMB_READ_OPER) {
+ npcm_smb_read_from_fifo(bus, bytes_in_fifo);
+
+ // Slave done transmitting or receiving
+ // if the buffer is empty nothing will be sent
+ }
+
+ // Slave done transmitting or receiving
+ // if the buffer is empty nothing will be sent
+ npcm_i2c_slave_send_rd_buf(bus);
+
+ bus->stop_ind = SMB_NO_STATUS_IND;
+
+ // Note, just because we got here, it doesn't mean we through
+ // away the wr buffer.
+ // we keep it until the next received offset.
+ bus->operation = SMB_NO_OPER;
+ bus->int_cnt = 0;
+ bus->event_log_prev = bus->event_log;
+ bus->event_log = 0;
+ bus->own_slave_addr = 0xFF;
+
+ i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0);
+
+ iowrite8(NPCM_SMBST_SLVSTP, bus->reg + NPCM_SMBST);
+
+ if (bus->fifo_use) {
+ npcm_smb_clear_fifo_int(bus);
+ npcm_smb_clear_rx_fifo(bus);
+ npcm_smb_clear_tx_fifo(bus);
+
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+ }
+
+ bus->state = SMB_IDLE;
+ ret = IRQ_HANDLED;
+ }
+
+ // restart condition occurred and Rx-FIFO was not empty
+ if (bus->fifo_use && FIELD_GET(NPCM_SMBFIF_CTS_SLVRSTR,
+ ioread8(bus->reg + NPCM_SMBFIF_CTS))) {
+ bus->stop_ind = SMB_SLAVE_RESTART_IND;
+
+ bus->master_or_slave = SMB_SLAVE;
+
+ if (bus->operation == SMB_READ_OPER)
+ npcm_smb_read_from_fifo(bus,
+ npcm_smb_get_fifo_fullness(bus)
+ );
+
+ bus->operation = SMB_WRITE_OPER;
+
+ iowrite8(0, bus->reg + NPCM_SMBRXF_CTL);
+
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO | NPCM_SMBFIF_CTS_SLVRSTR |
+ NPCM_SMBFIF_CTS_RXF_TXE, bus->reg + NPCM_SMBFIF_CTS);
+
+ npcm_i2c_slave_rd_wr(bus);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // A Slave Address Match has been identified
+ if (FIELD_GET(NPCM_SMBST_NMATCH, smbst)) {
+ u8 info = 0;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_SLV);
+ // Address match automatically implies slave mode
+ bus->master_or_slave = SMB_SLAVE;
+
+ npcm_smb_clear_fifo_int(bus);
+ npcm_smb_clear_rx_fifo(bus);
+ npcm_smb_clear_tx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ iowrite8(SMBUS_FIFO_SIZE, bus->reg + NPCM_SMBRXF_CTL);
+
+ if (FIELD_GET(NPCM_SMBST_XMIT, smbst)) {
+ bus->operation = SMB_WRITE_OPER;
+ } else {
+ i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_REQUESTED,
+ &info);
+ bus->operation = SMB_READ_OPER;
+ }
+
+ if (bus->own_slave_addr == 0xFF) { // unknown address
+ // Check which type of address match
+ if (FIELD_GET(NPCM_SMBCST_MATCH,
+ ioread8(bus->reg + NPCM_SMBCST))) {
+ u16 addr;
+ enum smb_addr eaddr;
+
+ addr = ((ioread8(bus->reg + NPCM_SMBCST3) &
+ 0x7) << 7) |
+ (ioread8(bus->reg + NPCM_SMBCST2) &
+ 0x7F);
+
+ info = ffs(addr);
+ eaddr = (enum smb_addr)info;
+
+ addr = FIELD_GET(NPCM_SMBADDR_A,
+ npcm_smb_get_slave_addr(bus,
+ eaddr)
+ );
+ bus->own_slave_addr = addr;
+
+ if (bus->PEC_mask & BIT(info))
+ bus->PEC_use = true;
+ else
+ bus->PEC_use = false;
+ } else {
+ if (FIELD_GET(NPCM_SMBCST_GCMATCH,
+ ioread8(bus->reg + NPCM_SMBCST)))
+ bus->own_slave_addr = 0;
+ if (FIELD_GET(NPCM_SMBCST_ARPMATCH,
+ ioread8(bus->reg + NPCM_SMBCST)))
+ bus->own_slave_addr = 0x61;
+ }
+ } else {
+ // Slave match can happen in two options:
+ // 1. Start, SA, read (slave read without further ado)
+ // 2. Start, SA, read, data, restart, SA, read, ...
+ // (slave read in fragmented mode)
+ // 3. Start, SA, write, data, restart, SA, read, ..
+ // (regular write-read mode)
+ if ((bus->state == SMB_OPER_STARTED &&
+ bus->operation == SMB_READ_OPER &&
+ bus->stop_ind == SMB_SLAVE_XMIT_IND) ||
+ bus->stop_ind == SMB_SLAVE_RCV_IND) {
+ // slave transmit after slave receive w/o Slave
+ // Stop implies repeated start
+ bus->stop_ind = SMB_SLAVE_RESTART_IND;
+ }
+ }
+
+ if (FIELD_GET(NPCM_SMBST_XMIT, smbst))
+ bus->stop_ind = SMB_SLAVE_XMIT_IND;
+ else
+ bus->stop_ind = SMB_SLAVE_RCV_IND;
+
+ bus->state = SMB_SLAVE_MATCH;
+
+ npcm_i2c_slave_rd_wr(bus);
+
+ iowrite8(NPCM_SMBST_NMATCH, bus->reg + NPCM_SMBST);
+ ret = IRQ_HANDLED;
+ }
+
+ // Slave SDA status is set - transmit or receive, slave
+ if (FIELD_GET(NPCM_SMBST_SDAST, smbst) ||
+ (bus->fifo_use &&
+ (npcm_smb_tx_fifo_empty(bus) || npcm_smb_rx_fifo_full(bus)))) {
+ npcm_i2c_slave_rd_wr(bus);
+
+ iowrite8(NPCM_SMBST_SDAST, bus->reg + NPCM_SMBST);
+
+ ret = IRQ_HANDLED;
+ } //SDAST
+
+ return ret;
+}
+
+static int npcm_i2c_reg_slave(struct i2c_client *client)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = i2c_get_adapdata(client->adapter);
+
+ bus->slave = client;
+
+ if (!bus->slave)
+ return -EINVAL;
+
+ if (client->flags & I2C_CLIENT_TEN)
+ return -EAFNOSUPPORT;
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+
+ npcm_smb_init_params(bus);
+ bus->slv_rd_size = 0;
+ bus->slv_wr_size = 0;
+ bus->slv_rd_ind = 0;
+ bus->slv_wr_ind = 0;
+ if (client->flags & I2C_CLIENT_PEC)
+ bus->PEC_use = true;
+
+ dev_info(bus->dev, "I2C%d register slave SA=0x%x, PEC=%d\n", bus->num,
+ client->addr, bus->PEC_use);
+
+ npcm_smb_slave_enable_l(bus, SMB_SLAVE_ADDR1, client->addr, true);
+
+ npcm_smb_clear_fifo_int(bus);
+ npcm_smb_clear_rx_fifo(bus);
+ npcm_smb_clear_tx_fifo(bus);
+
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+
+ return 0;
+}
+
+static int npcm_i2c_unreg_slave(struct i2c_client *client)
+{
+ struct npcm_i2c *bus = client->adapter->algo_data;
+ unsigned long lock_flags;
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ if (!bus->slave) {
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ return -EINVAL;
+ }
+
+ npcm_smb_remove_slave_addr(bus, client->addr);
+
+ bus->slave = NULL;
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+
+ return 0;
+}
+#endif // CONFIG_I2C_SLAVE
+
+static void npcm_smb_master_fifo_read(struct npcm_i2c *bus)
+{
+ int rcount;
+ int fifo_bytes;
+ enum smb_state_ind ind = SMB_MASTER_DONE_IND;
+
+ fifo_bytes = npcm_smb_get_fifo_fullness(bus);
+
+ rcount = bus->rd_size - bus->rd_ind;
+
+ // In order not to change the RX_TRH during transaction (we found that
+ // this might be problematic if it takes too much time to read the FIFO)
+ // we read the data in the following way. If the number of bytes to
+ // read == FIFO Size + C (where C < FIFO Size)then first read C bytes
+ // and in the next int we read rest of the data.
+ if (rcount < (2 * SMBUS_FIFO_SIZE) && rcount > SMBUS_FIFO_SIZE)
+ fifo_bytes = (u8)(rcount - SMBUS_FIFO_SIZE);
+
+ if ((rcount - fifo_bytes) <= 0) {
+ // last bytes are about to be read - end of transaction.
+ // Stop should be set before reading last byte.
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ4);
+
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = ind;
+
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+ npcm_smb_read_from_fifo(bus, fifo_bytes);
+ } else {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ3);
+ npcm_smb_read_from_fifo(bus, fifo_bytes);
+ rcount = bus->rd_size - bus->rd_ind;
+ npcm_smb_set_fifo(bus, rcount, -1);
+ }
+}
+
+static void npcm_smb_int_master_handler_write(struct npcm_i2c *bus)
+{
+ u16 wcount;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_WRITE);
+ if (bus->fifo_use)
+ npcm_smb_clear_tx_fifo(bus); // clear the TX fifo status bit
+
+ // Master write operation - last byte handling
+ if (bus->wr_ind == bus->wr_size) {
+ if (bus->fifo_use && npcm_smb_get_fifo_fullness(bus) > 0)
+ // No more bytes to send (to add to the FIFO),
+ // however the FIFO is not empty yet. It is
+ // still in the middle of tx. Currently there's nothing
+ // to do except for waiting to the end of the tx.
+ // We will get an int when the FIFO will get empty.
+ return;
+
+ if (bus->rd_size == 0) {
+ // all bytes have been written, in a pure wr operation
+ npcm_smb_eob_int(bus, true);
+
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = SMB_MASTER_DONE_IND;
+
+ npcm_smb_master_stop(bus);
+ // Clear SDA Status bit (by writing dummy byte)
+ npcm_smb_wr_byte(bus, 0xFF);
+
+ } else {
+ // last write-byte written on previous int - need to
+ // restart & send slave address
+ npcm_smb_set_fifo(bus, bus->rd_size, -1);
+
+ // Generate repeated start upon next write to SDA
+ npcm_smb_master_start(bus);
+
+ if (bus->rd_size == 1)
+ // Receiving one byte only - stall after
+ // successful completion of send
+ // address byte. If we NACK here,
+ // and slave doesn't ACK the address, we
+ // might unintentionally NACK the next
+ // multi-byte read
+ npcm_smb_stall_after_start(bus, true);
+
+ // Next int will occur on read
+ bus->operation = SMB_READ_OPER;
+
+ // send the slave address in read direction
+ npcm_smb_wr_byte(bus, bus->dest_addr | 0x1);
+ }
+ } else {
+ // write next byte not last byte and not slave address
+ if (!bus->fifo_use || bus->wr_size == 1) {
+ npcm_smb_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
+ } else {
+ wcount = bus->wr_size - bus->wr_ind;
+ npcm_smb_set_fifo(bus, -1, wcount);
+ npcm_smb_write_to_fifo_master(bus, wcount);
+ }
+ }
+}
+
+static void npcm_smb_int_master_handler_read(struct npcm_i2c *bus)
+{
+ u16 block_extra_bytes_size;
+ u8 data;
+
+ // Master read operation (pure read or following a write operation).
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ);
+
+ // added bytes to the packet:
+ block_extra_bytes_size = (u8)bus->read_block_use + (u8)bus->PEC_use;
+
+ // Perform master read, distinguishing between last byte and the rest of
+ // the bytes. The last byte should be read when the clock is stopped
+ if (bus->rd_ind == 0) { //first byte handling:
+ // in block protocol first byte is the size
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ1);
+ if (bus->read_block_use) {
+ // first byte in block protocol is the size:
+ npcm_smb_rd_byte(bus, &data);
+
+ // if slave returned illegal size. read up to 32 bytes.
+ if (data >= I2C_SMBUS_BLOCK_MAX)
+ data = I2C_SMBUS_BLOCK_MAX;
+
+ // is data is 0 -> not supported. read at least one byte
+ if (data == 0)
+ data = 1;
+
+ bus->rd_size = data + block_extra_bytes_size;
+
+ bus->rd_buf[bus->rd_ind++] = data;
+
+ // clear RX FIFO interrupt status:
+ if (bus->fifo_use) {
+ iowrite8(NPCM_SMBFIF_CTS_RXF_TXE |
+ ioread8(bus->reg + NPCM_SMBFIF_CTS),
+ bus->reg + NPCM_SMBFIF_CTS);
+ }
+
+ npcm_smb_set_fifo(bus, (bus->rd_size - 1), -1);
+ npcm_smb_stall_after_start(bus, false);
+ } else {
+ npcm_smb_clear_tx_fifo(bus);
+ npcm_smb_master_fifo_read(bus);
+ }
+ } else {
+ if (bus->rd_size == block_extra_bytes_size &&
+ bus->read_block_use) {
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = SMB_BLOCK_BYTES_ERR_IND;
+ bus->cmd_err = -EIO;
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+ npcm_smb_read_from_fifo(bus,
+ npcm_smb_get_fifo_fullness(bus)
+ );
+ } else {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ2);
+ npcm_smb_master_fifo_read(bus);
+ }
+ }
+}
+
+static irqreturn_t npcm_smb_int_master_handler(struct npcm_i2c *bus)
+{
+ irqreturn_t ret = IRQ_NONE;
+ u8 fif_cts;
+
+ if (FIELD_GET(NPCM_SMBST_NMATCH, ioread8(bus->reg + NPCM_SMBST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_MSTR);
+ iowrite8(NPCM_SMBST_NMATCH, bus->reg + NPCM_SMBST);
+ npcm_smb_nack(bus);
+ bus->stop_ind = SMB_BUS_ERR_IND;
+ npcm_smb_callback(bus, bus->stop_ind, npcm_smb_get_index(bus));
+
+ return IRQ_HANDLED;
+ }
+ // A NACK has occurred
+ if (FIELD_GET(NPCM_SMBST_NEGACK, ioread8(bus->reg + NPCM_SMBST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK);
+ if (bus->fifo_use) {
+ // if there are still untransmitted bytes in TX FIFO
+ // reduce them from wr_ind
+ if (bus->operation == SMB_WRITE_OPER)
+ bus->wr_ind -= npcm_smb_get_fifo_fullness(bus);
+
+ // clear the FIFO
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+ }
+
+ // In master write operation, NACK is a problem
+ // number of bytes sent to master less than required
+ bus->stop_ind = SMB_NACK_IND;
+ // Only current master is allowed to issue Stop Condition
+ if (npcm_smb_is_master(bus)) {
+ // stopping in the middle, not waiting for ints anymore
+ npcm_smb_eob_int(bus, false);
+
+ npcm_smb_master_stop(bus);
+
+ // Clear NEGACK, STASTR and BER bits
+ // In Master mode, NEGACK should be cleared only after
+ // generating STOP.
+ // In such case, the bus is released from stall only
+ // after the software clears NEGACK bit.
+ // Then a Stop condition is sent.
+ iowrite8(NPCM_SMBST_BER | NPCM_SMBST_NEGACK |
+ NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST);
+
+ npcm_smb_wait_for_bus_free(bus, false);
+ }
+ bus->state = SMB_IDLE;
+
+ // In Master mode, NACK should be cleared only after
+ // generating STOP.
+ // In such case, the bus is released from stall only after the
+ // software clears NACK bit.
+ // Then a Stop condition is sent.
+ npcm_smb_callback(bus, bus->stop_ind, bus->wr_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Master mode: a Bus Error has been identified
+ if (FIELD_GET(NPCM_SMBST_BER, ioread8(bus->reg + NPCM_SMBST))) {
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_BER);
+ bus->stop_ind = SMB_BUS_ERR_IND;
+ if (npcm_smb_is_master(bus)) {
+ npcm_smb_master_abort(bus);
+ } else {
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_SMBST_BER | NPCM_SMBST_NEGACK |
+ NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST);
+
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST);
+
+ bus->cmd_err = -EAGAIN;
+ npcm_smb_callback(bus, bus->stop_ind,
+ npcm_smb_get_index(bus));
+ }
+ bus->state = SMB_IDLE;
+ ret = IRQ_HANDLED;
+ return ret;
+ }
+
+ // A Master End of Busy (meaning Stop Condition happened)
+ // End of Busy int is on and End of Busy is set
+ if ((FIELD_GET(NPCM_SMBCTL1_EOBINTE,
+ ioread8(bus->reg + NPCM_SMBCTL1)) == 1) &&
+ (FIELD_GET(NPCM_SMBCST3_EO_BUSY,
+ ioread8(bus->reg + NPCM_SMBCST3)))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_EOB);
+ npcm_smb_eob_int(bus, false);
+ bus->state = SMB_IDLE;
+ npcm_smb_callback(bus, bus->stop_ind, bus->rd_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Address sent and requested stall occurred (Master mode)
+ if (FIELD_GET(NPCM_SMBST_STASTR, ioread8(bus->reg + NPCM_SMBST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STALL);
+
+ if (npcm_smb_is_quick(bus)) {
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = SMB_MASTER_DONE_IND;
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+
+ } else if ((bus->rd_size == 1) && !bus->read_block_use) {
+ // Receiving one byte only - set NACK after ensuring
+ // slave ACKed the address byte
+ npcm_smb_nack(bus);
+ }
+
+ // Reset stall-after-address-byte
+ npcm_smb_stall_after_start(bus, false);
+
+ // Clear stall only after setting STOP
+ iowrite8(NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // SDA status is set - TX or RX, master
+ if (FIELD_GET(NPCM_SMBST_SDAST, ioread8(bus->reg + NPCM_SMBST)) ||
+ (bus->fifo_use &&
+ (npcm_smb_tx_fifo_empty(bus) || npcm_smb_rx_fifo_full(bus)))) {
+ // Status Bit is cleared by writing to or reading from SDA
+ // (depending on current direction)
+
+ // Send address:
+ if (bus->state == SMB_IDLE) {
+ if (npcm_smb_is_master(bus)) {
+ bus->stop_ind = SMB_WAKE_UP_IND;
+
+ // test stall on start
+ if (npcm_smb_is_quick(bus) ||
+ bus->read_block_use)
+ // Need to stall after successful
+ // completion of sending address byte
+ npcm_smb_stall_after_start(bus, true);
+ else
+ npcm_smb_stall_after_start(bus, false);
+
+ // Receiving one byte only - stall after
+ // successful completion of sending address byte
+ // If we NACK here, and slave doesn't ACK the
+ // address, we might unintentionally NACK
+ // the next multi-byte read
+ if (bus->wr_size == 0 && bus->rd_size == 1)
+ npcm_smb_stall_after_start(bus, true);
+
+ // Initiate SMBus master transaction
+ // Generate a Start condition on the SMBus
+
+ // select bank 1 for FIFO regs
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ fif_cts = ioread8(bus->reg + NPCM_SMBFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((fif_cts & ~NPCM_SMBFIF_CTS_SLVRSTR)
+ | NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+
+ // and enable it
+ iowrite8((fif_cts & ~NPCM_SMBFIF_CTS_SLVRSTR)
+ | NPCM_SMBFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_SMBFIF_CTS);
+
+ // Configure the FIFO threshold
+ // according to the needed # of bytes to read.
+ // Note: due to HW limitation can't config the
+ // rx fifo before
+ // got and ACK on the restart. LAST bit will not
+ // be reset unless RX completed.
+ // It will stay set on the next tx.
+ if (bus->wr_size)
+ npcm_smb_set_fifo(bus, -1,
+ bus->wr_size);
+ else
+ npcm_smb_set_fifo(bus, bus->rd_size,
+ -1);
+
+ bus->state = SMB_OPER_STARTED;
+
+ if (npcm_smb_is_quick(bus) || bus->wr_size)
+ npcm_smb_wr_byte(bus, bus->dest_addr);
+ else
+ npcm_smb_wr_byte(bus, bus->dest_addr |
+ 0x01);
+ }
+
+ return IRQ_HANDLED;
+ // SDA status is set - transmit or receive: Handle master mode
+ } else {
+ if ((NPCM_SMBST_XMIT &
+ ioread8(bus->reg + NPCM_SMBST)) == 0) {
+ bus->operation = SMB_READ_OPER;
+ npcm_smb_int_master_handler_read(bus);
+ } else {
+ bus->operation = SMB_WRITE_OPER;
+ npcm_smb_int_master_handler_write(bus);
+ }
+ }
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static int npcm_smb_get_SCL(struct i2c_adapter *_adap)
+{
+ unsigned int ret = 0;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ u32 offset = 0;
+
+ offset = 0;
+ ret = FIELD_GET(SMBCTL3_SCL_LVL, ioread32(bus->reg + NPCM_SMBCTL3));
+
+ pr_debug("i2c%d get SCL 0x%08X\n", bus->num, ret);
+
+ return (ret >> (offset)) & 0x01;
+}
+
+static int npcm_smb_get_SDA(struct i2c_adapter *_adap)
+{
+ unsigned int ret = 0;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ u32 offset = 0;
+
+ offset = 0;
+ ret = FIELD_GET(SMBCTL3_SDA_LVL, ioread32(bus->reg + NPCM_SMBCTL3));
+
+ pr_debug("i2c%d get SDA 0x%08X\n", bus->num, ret);
+
+ return (ret >> (offset)) & 0x01;
+}
+
+// recovery using TGCLK functionality of the module
+static int npcm_smb_recovery_tgclk(struct i2c_adapter *_adap)
+{
+ int iter = 27; // Allow 3 bytes to be sent by the Slave
+ int retries = 0;
+ bool done = false;
+ int status = -(ENOTRECOVERABLE);
+ u8 fif_cts;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+
+ dev_dbg(bus->dev, "TGCLK recovery bus%d\n", bus->num);
+
+ if ((npcm_smb_get_SDA(_adap) == 1) && (npcm_smb_get_SCL(_adap) == 1)) {
+ dev_dbg(bus->dev, "TGCLK recovery bus%d: skipped bus not stuck",
+ bus->num);
+ npcm_smb_reset(bus);
+ return status;
+ }
+
+ // Disable int
+ npcm_smb_int_enable(bus, false);
+
+ npcm_smb_disable(bus);
+ npcm_smb_enable(bus);
+ iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST);
+ npcm_smb_clear_tx_fifo(bus);
+ npcm_smb_clear_rx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_SMBRXF_CTL);
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ npcm_smb_stall_after_start(bus, false);
+
+ // select bank 1 for FIFO regs
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ fif_cts = ioread8(bus->reg + NPCM_SMBFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((fif_cts & ~NPCM_SMBFIF_CTS_SLVRSTR) |
+ NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+
+ npcm_smb_set_fifo(bus, -1, 0);
+
+ // Check If the SDA line is active (low)
+ if (npcm_smb_get_SDA(_adap) == 0) {
+ // Repeat the following sequence until SDA is released
+ do {
+ // Issue a single SCL cycle
+ iowrite8(NPCM_SMBCST_TGSCL, bus->reg + NPCM_SMBCST);
+ retries = 10;
+ while (retries != 0 &&
+ FIELD_GET(NPCM_SMBCST_TGSCL,
+ ioread8(bus->reg + NPCM_SMBCST))) {
+ udelay(20);
+ retries--;
+ }
+
+ // tgclk failed to toggle
+ if (retries == 0)
+ dev_dbg(bus->dev, "\t toggle timeout\n");
+ // If SDA line is inactive (high), stop
+ if (npcm_smb_get_SDA(_adap))
+ done = true;
+ } while ((!done) && (--iter != 0));
+
+ // If SDA line is released: send start-addr-stop, to re-sync.
+ if (done) {
+ npcm_smb_master_start(bus);
+
+ // Wait until START condition is sent, or RETRIES_NUM
+ retries = RETRIES_NUM;
+ while (retries && !npcm_smb_is_master(bus)) {
+ udelay(20);
+ retries--;
+ }
+
+ // If START condition was sent
+ if (retries > 0) {
+ // Send an address byte in write direction:
+ npcm_smb_wr_byte(bus, bus->dest_addr);
+ udelay(200);
+ npcm_smb_master_stop(bus);
+ udelay(200);
+ status = 0;
+ }
+ }
+ }
+
+ // if bus is still stuck: total reset: set SCL low for 35ms:
+ if (unlikely(npcm_smb_get_SDA(_adap) == 0)) {
+ // Generate a START, to synchronize Master and Slave
+ npcm_smb_master_start(bus);
+
+ // Wait until START condition is sent, or RETRIES_NUM
+ retries = RETRIES_NUM;
+ while (retries && !npcm_smb_is_master(bus))
+ retries--;
+
+ // set SCL low for a long time (note: this is unlikely)
+ usleep_range(25000, 35000);
+ npcm_smb_master_stop(bus);
+ udelay(200);
+ status = 0;
+ }
+
+ dev_dbg(bus->dev, "TGCLK done, iter = %d, done = %d, retries = %d\n",
+ 27 - iter, done, retries);
+ // Enable SMB int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) &
+ ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ npcm_smb_reset(bus);
+ npcm_smb_int_enable(bus, true);
+ return status;
+}
+
+// recovery using bit banging functionality of the module
+static int npcm_smb_recovery_init(struct i2c_adapter *_adap)
+{
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ struct i2c_bus_recovery_info *rinfo = &bus->rinfo;
+
+ rinfo->recover_bus = npcm_smb_recovery_tgclk;
+ rinfo->prepare_recovery = NULL;
+ rinfo->unprepare_recovery = NULL;
+ rinfo->set_scl = NULL;
+ rinfo->set_sda = NULL;
+
+ dev_dbg(bus->dev, "i2c gpio recovery using TGCLK\n");
+
+ rinfo->get_scl = npcm_smb_get_SCL;
+ rinfo->get_sda = npcm_smb_get_SDA;
+
+ _adap->bus_recovery_info = rinfo;
+
+ return 0;
+}
+
+static bool npcm_smb_init_clk(struct npcm_i2c *bus, u32 bus_freq)
+{
+ u32 k1 = 0;
+ u32 k2 = 0;
+ u8 dbnct = 0;
+ u32 sclfrq = 0;
+ u8 hldt = 7;
+ bool fast_mode = false;
+ u32 src_clk_freq; // in KHz
+
+ src_clk_freq = bus->apb_clk / 1000;
+ bus->bus_freq = bus_freq;
+
+ if (bus_freq <= SMBUS_FREQ_100KHZ) {
+ sclfrq = src_clk_freq / (bus_freq * 4);
+
+ if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
+ return false;
+
+ if (src_clk_freq >= 40000)
+ hldt = 17;
+ else if (src_clk_freq >= 12500)
+ hldt = 15;
+ else
+ hldt = 7;
+ }
+
+ else if (bus_freq == SMBUS_FREQ_400KHZ) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if (src_clk_freq < 7500)
+ // 400KHZ cannot be supported for core clock < 7.5 MHZ
+ return false;
+
+ else if (src_clk_freq >= 50000) {
+ k1 = 80;
+ k2 = 48;
+ hldt = 12;
+ dbnct = 7;
+ }
+
+ // Master or Slave with frequency > 25 MHZ
+ else if (src_clk_freq > 25000) {
+ hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 300,
+ 1000000) + 7;
+
+ k1 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 1600,
+ 1000000);
+ k2 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 900,
+ 1000000);
+ k1 = round_up(k1, 2);
+ k2 = round_up(k2 + 1, 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return false;
+ }
+ }
+
+ else if (bus_freq == SMBUS_FREQ_1MHZ) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if (src_clk_freq < 24000)
+ // 1MHZ cannot be supported for master core clock < 15 MHZ
+ // or slave core clock < 24 MHZ
+ return false;
+
+ k1 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 620,
+ 1000000)), 2);
+ k2 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 380,
+ 1000000) + 1), 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return false;
+
+ // Master or Slave with frequency > 40 MHZ
+ if (src_clk_freq > 40000) {
+ // Set HLDT:
+ // SDA hold time: (HLDT-7) * T(CLK) >= 120
+ // HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7
+ hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 120,
+ 1000000) + 7;
+ } else {
+ hldt = 7;
+ dbnct = 2;
+ }
+ }
+
+ // Frequency larger than 1 MHZ
+ else
+ return false;
+
+ // After clock parameters calculation update reg (ENABLE should be 0):
+ iowrite8(FIELD_PREP(SMBCTL2_SCLFRQ6_0, sclfrq & 0x7F),
+ bus->reg + NPCM_SMBCTL2);
+
+ // force to bank 0, set SCL and fast mode
+ iowrite8(FIELD_PREP(SMBCTL3_400K_MODE, fast_mode) |
+ FIELD_PREP(SMBCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
+ bus->reg + NPCM_SMBCTL3);
+
+ // Select Bank 0 to access NPCM_SMBCTL4/NPCM_SMBCTL5
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ if (bus_freq >= SMBUS_FREQ_400KHZ) {
+ // Set SCL Low/High Time:
+ // k1 = 2 * SCLLT7-0 -> Low Time = k1 / 2
+ // k2 = 2 * SCLLT7-0 -> High Time = k2 / 2
+ iowrite8((u8)k1 / 2, bus->reg + NPCM_SMBSCLLT);
+ iowrite8((u8)k2 / 2, bus->reg + NPCM_SMBSCLHT);
+
+ iowrite8(dbnct, bus->reg + NPCM_SMBCTL5);
+ }
+
+ iowrite8(hldt, bus->reg + NPCM_SMBCTL4);
+
+ // Return to Bank 1, and stay there by default:
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ return true;
+}
+
+static bool npcm_smb_init_module(struct npcm_i2c *bus, enum smb_mode mode,
+ u32 bus_freq)
+{
+ // Check whether module already enabled or frequency is out of bounds
+ if ((bus->state != SMB_DISABLE && bus->state != SMB_IDLE) ||
+ bus_freq < SMBUS_FREQ_MIN || bus_freq > SMBUS_FREQ_MAX)
+ return false;
+
+ npcm_smb_disable(bus);
+
+ // Configure FIFO mode :
+ if (FIELD_GET(SMB_VER_FIFO_EN, ioread8(bus->reg + SMB_VER))) {
+ bus->fifo_use = true;
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+ iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTL) |
+ NPCM_SMBFIF_CTL_FIFO_EN, bus->reg + NPCM_SMBFIF_CTL);
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ } else {
+ bus->fifo_use = false;
+ }
+
+ // Configure SMB module clock frequency
+ if (!npcm_smb_init_clk(bus, bus_freq)) {
+ dev_err(bus->dev, "npcm_smb_init_clk failed\n");
+ return false;
+ }
+
+ // Enable module (before configuring CTL1)
+ npcm_smb_enable(bus);
+ bus->state = SMB_IDLE;
+
+ // Enable SMB int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) &
+ ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+
+ npcm_smb_int_enable(bus, true);
+
+ npcm_smb_reset(bus);
+
+ return true;
+}
+
+static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
+{
+ u32 clk_freq;
+ int ret;
+
+ // Initialize the internal data structures
+ bus->state = SMB_DISABLE;
+ bus->master_or_slave = SMB_SLAVE;
+ bus->int_time_stamp = 0;
+ bus->slave = NULL;
+ bus->xmits = 0;
+
+ ret = of_property_read_u32(pdev->dev.of_node,
+ "bus-frequency", &clk_freq);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Could not read bus-frequency property\n");
+ clk_freq = 100000;
+ }
+
+ ret = npcm_smb_init_module(bus, SMB_MASTER, clk_freq / 1000);
+ if (!ret) {
+ dev_err(&pdev->dev,
+ "npcm_smb_init_module() failed\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
+{
+ irqreturn_t ret;
+ struct npcm_i2c *bus = dev_id;
+
+ bus->int_cnt++;
+
+ if (npcm_smb_is_master(bus))
+ bus->master_or_slave = SMB_MASTER;
+
+ if (bus->master_or_slave == SMB_MASTER) {
+ bus->int_time_stamp = jiffies;
+ ret = npcm_smb_int_master_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ bus->master_or_slave = SMB_SLAVE;
+ ret = npcm_smb_int_slave_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+#endif
+ return IRQ_HANDLED;
+}
+
+static bool npcm_smb_master_start_xmit(struct npcm_i2c *bus,
+ u8 slave_addr, u16 nwrite, u16 nread,
+ u8 *write_data, u8 *read_data,
+ bool use_PEC, bool use_read_block)
+{
+ if (bus->state != SMB_IDLE) {
+ bus->cmd_err = -(EBUSY);
+ return false;
+ }
+
+ bus->xmits++;
+
+ bus->dest_addr = (u8)(slave_addr << 1);// Translate 7bit to 8bit format
+ bus->wr_buf = write_data;
+ bus->wr_size = nwrite;
+ bus->wr_ind = 0;
+ bus->rd_buf = read_data;
+ bus->rd_size = nread;
+ bus->rd_ind = 0;
+ bus->PEC_use = 0;
+
+ // for write, PEC is appended to buffer from i2c IF. PEC flag is ignored
+ if (nread)
+ bus->PEC_use = use_PEC;
+ bus->read_block_use = use_read_block;
+ if (nread && !nwrite)
+ bus->operation = SMB_READ_OPER;
+ else
+ bus->operation = SMB_WRITE_OPER;
+
+ bus->int_cnt = 0;
+ bus->event_log = 0;
+
+ if (bus->fifo_use) {
+ u8 smbfif_cts;
+ // select bank 1 for FIFO regs
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ smbfif_cts = ioread8(bus->reg + NPCM_SMBFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((smbfif_cts & (~NPCM_SMBFIF_CTS_SLVRSTR)) |
+ NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+ }
+
+ bus->state = SMB_IDLE;
+
+ npcm_smb_stall_after_start(bus, true);
+ npcm_smb_master_start(bus);
+
+ return true;
+}
+
+static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct npcm_i2c *bus = container_of(adap, struct npcm_i2c, adap);
+ struct i2c_msg *msg0, *msg1;
+ unsigned long time_left, flags;
+ u16 nwrite, nread;
+ u8 *write_data, *read_data;
+ u8 slave_addr;
+ int timeout;
+ int ret = 0;
+ bool read_block = false;
+ bool read_PEC = false;
+ u8 bus_busy;
+ unsigned long timeout_usec;
+
+ if (unlikely(bus->state == SMB_DISABLE)) {
+ dev_err(bus->dev, "I2C%d module is disabled", bus->num);
+ return -EINVAL;
+ }
+
+ if (num > 2 || num < 1) {
+ dev_err(bus->dev, "I2C cmd not supported num of msgs=%d", num);
+ return -EINVAL;
+ }
+
+ msg0 = &msgs[0];
+ slave_addr = msg0->addr;
+ if (msg0->flags & I2C_M_RD) { // read
+ if (num == 2) {
+ dev_err(bus->dev, "num=2 but 1st msg rd instead of wr");
+ return -EINVAL;
+ }
+ nwrite = 0;
+ write_data = NULL;
+ read_data = msg0->buf;
+ if (msg0->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ read_block = true;
+ if (msg0->flags & I2C_CLIENT_PEC)
+ read_PEC = true;
+ } else {
+ nread = msg0->len;
+ }
+ } else { // write
+ nwrite = msg0->len;
+ write_data = msg0->buf;
+ nread = 0;
+ read_data = NULL;
+ if (num == 2) {
+ msg1 = &msgs[1];
+ read_data = msg1->buf;
+ if (slave_addr != msg1->addr) {
+ dev_err(bus->dev,
+ "SA==%02x but msg1->addr==%02x\n",
+ slave_addr, msg1->addr);
+ return -EINVAL;
+ }
+ if ((msg1->flags & I2C_M_RD) == 0) {
+ dev_err(bus->dev,
+ "num = 2 but both msg are write.\n");
+ return -EINVAL;
+ }
+ if (msg1->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ read_block = true;
+ if (msg1->flags & I2C_CLIENT_PEC)
+ read_PEC = true;
+ } else {
+ nread = msg1->len;
+ read_block = false;
+ }
+ }
+ }
+
+ /* Adaptive TimeOut: astimated time in usec + 100% margin */
+ timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite);
+ timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec));
+ if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
+ dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
+ return -EINVAL;
+ }
+
+ time_left = jiffies +
+ msecs_to_jiffies(DEFAULT_STALL_COUNT) + 1;
+ do {
+ /* we must clear slave address immediately when the bus is not
+ * busy, so we spinlock it, but we don't keep the lock for the
+ * entire while since it is too long.
+ */
+ spin_lock_irqsave(&bus->lock, flags);
+ bus_busy = ioread8(bus->reg + NPCM_SMBCST) & NPCM_SMBCST_BB;
+ if (!bus_busy && bus->slave)
+ iowrite8((bus->slave->addr & 0x7F),
+ bus->reg + NPCM_SMBADDR1);
+ spin_unlock_irqrestore(&bus->lock, flags);
+
+ if (!bus_busy)
+ break;
+ } while (time_is_after_jiffies(time_left));
+
+ if (bus_busy) {
+ iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST);
+ npcm_smb_reset(bus);
+ i2c_recover_bus(adap);
+ return -EAGAIN;
+ }
+
+ npcm_smb_init_params(bus);
+ bus->dest_addr = slave_addr;
+ bus->msgs = msgs;
+ bus->msgs_num = num;
+ bus->read_block_use = read_block;
+
+ reinit_completion(&bus->cmd_complete);
+
+ if (!npcm_smb_master_start_xmit(bus, slave_addr, nwrite, nread,
+ write_data, read_data, read_PEC,
+ read_block))
+ ret = -(EBUSY);
+
+ if (ret != -(EBUSY)) {
+ time_left = wait_for_completion_timeout(&bus->cmd_complete,
+ timeout);
+
+ if (time_left == 0) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_TO);
+ if (bus->master_or_slave == SMB_MASTER) {
+ dev_dbg(bus->dev,
+ "i2c%d TO = %d\n", bus->num, timeout);
+ i2c_recover_bus(adap);
+ bus->cmd_err = -EIO;
+ bus->state = SMB_IDLE;
+ }
+ }
+ }
+ ret = bus->cmd_err;
+
+ // if there was BER, check if need to recover the bus:
+ if (bus->cmd_err == -EAGAIN)
+ i2c_recover_bus(adap);
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ // reenable slave if it was enabled
+ if (bus->slave)
+ iowrite8((bus->slave->addr & 0x7F) | NPCM_SMBADDR_SAEN,
+ bus->reg + NPCM_SMBADDR1);
+#endif
+
+ // If nothing went wrong, return number of messages x-ferred.
+ if (ret >= 0)
+ return num;
+
+ // print errors apart from NACK
+ if (bus->cmd_err == -ENXIO)
+ dev_dbg(bus->dev, "cmd failed cmd_err = %d\n", ret);
+ return ret;
+}
+
+static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA |
+ I2C_FUNC_SLAVE | I2C_FUNC_SMBUS_PEC;
+}
+
+static const struct i2c_adapter_quirks npcm_i2c_quirks = {
+ .max_read_len = 32768,
+ .max_write_len = 32768,
+ .max_num_msgs = 2,
+ .flags = I2C_AQ_COMB_WRITE_THEN_READ
+};
+
+static const struct i2c_algorithm npcm_i2c_algo = {
+ .master_xfer = npcm_i2c_master_xfer,
+ .functionality = npcm_i2c_functionality,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_slave = npcm_i2c_reg_slave,
+ .unreg_slave = npcm_i2c_unreg_slave,
+#endif
+};
+
+static int npcm_i2c_probe_bus(struct platform_device *pdev)
+{
+ struct npcm_i2c *bus;
+ struct i2c_adapter *adap;
+ struct resource *res;
+ struct clk *i2c_clk;
+ int ret;
+ int num;
+
+ bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+ if (!bus)
+ return -ENOMEM;
+
+#ifdef CONFIG_OF
+ num = of_alias_get_id(pdev->dev.of_node, "i2c");
+ bus->num = num;
+ i2c_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c_clk)) {
+ dev_err(bus->dev, " I2C probe failed: can't read clk\n");
+ return -EPROBE_DEFER;
+ }
+ bus->apb_clk = clk_get_rate(i2c_clk);
+ dev_dbg(bus->dev, "I2C APB clock is %d\n", bus->apb_clk);
+#endif // CONFIG_OF
+
+ gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
+ if (IS_ERR(gcr_regmap)) {
+ dev_err(bus->dev, "%s: failed to find nuvoton,npcm750-gcr\n",
+ __func__);
+ return IS_ERR(gcr_regmap);
+ }
+ regmap_write(gcr_regmap, NPCM_I2CSEGCTL, I2CSEGCTL_VAL);
+ dev_dbg(bus->dev, "I2C%d: gcr mapped\n", bus->num);
+
+ clk_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-clk");
+ if (IS_ERR(clk_regmap)) {
+ dev_err(bus->dev, "%s: failed to find nuvoton,npcm750-clk\n",
+ __func__);
+ return IS_ERR(clk_regmap);
+ }
+ dev_dbg(bus->dev, "I2C%d: clk mapped\n", bus->num);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dev_dbg(bus->dev, "resource: %pR\n", res);
+ bus->reg = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR((bus)->reg))
+ return PTR_ERR((bus)->reg);
+ dev_dbg(bus->dev, "base = %p\n", bus->reg);
+
+ // Initialize the I2C adapter
+ spin_lock_init(&bus->lock);
+ init_completion(&bus->cmd_complete);
+
+ adap = &bus->adap;
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLIENT_SLAVE;
+ adap->retries = 3;
+ adap->timeout = HZ;
+ adap->algo = &npcm_i2c_algo;
+ adap->quirks = &npcm_i2c_quirks;
+ adap->algo_data = bus;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+ adap->nr = pdev->id;
+
+ bus->dev = &pdev->dev;
+ bus->slave = NULL;
+
+ bus->irq = platform_get_irq(pdev, 0);
+ if (bus->irq < 0) {
+ dev_err(bus->dev, "I2C platform_get_irq error\n");
+ return -ENODEV;
+ }
+ dev_dbg(bus->dev, "irq = %d\n", bus->irq);
+
+ ret = devm_request_irq(&pdev->dev, bus->irq, npcm_i2c_bus_irq, 0,
+ dev_name(&pdev->dev), (void *)bus);
+
+ if (ret) {
+ dev_err(&pdev->dev, "I2C%d: request_irq fail\n", bus->num);
+ return ret;
+ }
+
+ ret = __npcm_i2c_init(bus, pdev);
+ if (ret < 0)
+ return ret;
+
+ ret = npcm_smb_recovery_init(adap);
+ if (ret)
+ return ret;
+
+ i2c_set_adapdata(adap, bus);
+
+ snprintf(bus->adap.name, sizeof(bus->adap.name), "Nuvoton i2c");
+
+ ret = i2c_add_numbered_adapter(&bus->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "I2C%d: i2c_add_numbered_adapter fail\n",
+ bus->num);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, bus);
+
+ pr_info("npcm7xx I2C bus is %d registered\n", bus->adap.nr);
+
+ return 0;
+}
+
+static int npcm_i2c_remove_bus(struct platform_device *pdev)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = platform_get_drvdata(pdev);
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ npcm_smb_disable(bus);
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ i2c_del_adapter(&bus->adap);
+
+ return 0;
+}
+
+static const struct of_device_id npcm_i2c_bus_of_table[] = {
+ { .compatible = "nuvoton,npcm750-i2c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
+
+static struct platform_driver npcm_i2c_bus_driver = {
+ .probe = npcm_i2c_probe_bus,
+ .remove = npcm_i2c_remove_bus,
+ .driver = {
+ .name = "nuvoton-i2c",
+ .of_match_table = npcm_i2c_bus_of_table,
+ }
+};
+module_platform_driver(npcm_i2c_bus_driver);
+
+MODULE_AUTHOR("Avi Fishman <avi.fishman@...il.com>");
+MODULE_AUTHOR("Tali Perry <tali.perry@...oton.com>");
+MODULE_AUTHOR("Tyrone Ting <kfting@...oton.com>");
+MODULE_DESCRIPTION("Nuvoton I2C Bus Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(I2C_VERSION);
--
2.22.0
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