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Message-Id: <20200301223201.185450-3-tali.perry1@gmail.com>
Date: Mon, 2 Mar 2020 00:32:00 +0200
From: Tali Perry <tali.perry1@...il.com>
To: brendanhiggins@...gle.com, avifishman70@...il.com,
tmaimon77@...il.com, kfting@...oton.com, venture@...gle.com,
yuenn@...gle.com, benjaminfair@...gle.com, robh+dt@...nel.org,
wsa@...-dreams.de, andriy.shevchenko@...ux.intel.com
Cc: linux-arm-kernel@...ts.infradead.org, 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 v8 2/3] i2c: npcm7xx: 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 | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-npcm7xx.c | 1888 ++++++++++++++++++++++++++++++
3 files changed, 1898 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 146ce40d8e0a..833349971260 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -786,6 +786,15 @@ 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 || COMPILE_TEST
+ help
+ If you say yes to this option, support will be included for the
+ Nuvoton I2C controller, which is available on the NPCM7xx BMC
+ controller.
+ Driver can also support slave mode (select I2C_SLAVE).
+
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..cef5288f0394
--- /dev/null
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -0,0 +1,1888 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NPCM7xx I2C Controller driver
+ *
+ * Copyright (C) 2020 Nuvoton Technologies tali.perry@...oton.com
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.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>
+
+enum i2c_mode {
+ I2C_MASTER,
+ I2C_SLAVE
+};
+
+/*
+ * External I2C Interface driver xfer indication values, which indicate status
+ * of the bus.
+ */
+enum i2c_state_ind {
+ I2C_NO_STATUS_IND = 0,
+ I2C_SLAVE_RCV_IND = 1,
+ I2C_SLAVE_XMIT_IND = 2,
+ I2C_SLAVE_XMIT_MISSING_DATA_IND = 3,
+ I2C_SLAVE_RESTART_IND = 4,
+ I2C_SLAVE_DONE_IND = 5,
+ I2C_MASTER_DONE_IND = 6,
+ I2C_NACK_IND = 8,
+ I2C_BUS_ERR_IND = 9,
+ I2C_WAKE_UP_IND = 10,
+ I2C_BLOCK_BYTES_ERR_IND = 12,
+ I2C_SLAVE_RCV_MISSING_DATA_IND = 14,
+};
+
+// I2Cus Operation type values
+enum i2c_oper {
+ I2C_NO_OPER = 0,
+ I2C_WRITE_OPER = 1,
+ I2C_READ_OPER = 2
+};
+
+// I2Cus Bank (FIFO mode)
+enum i2c_bank {
+ I2C_BANK_0 = 0,
+ I2C_BANK_1 = 1
+};
+
+// Internal I2C states values (for the I2C module state machine).
+enum i2c_state {
+ I2C_DISABLE = 0,
+ I2C_IDLE,
+ I2C_MASTER_START,
+ I2C_SLAVE_MATCH,
+ I2C_OPER_STARTED,
+ I2C_STOP_PENDING
+};
+
+// init register and default value required to enable module
+#define NPCM_I2CSEGCTL 0xE4
+#define I2CSEGCTL_VAL 0x0333F000
+
+// Common regs
+#define NPCM_I2CSDA 0x00
+#define NPCM_I2CST 0x02
+#define NPCM_I2CCST 0x04
+#define NPCM_I2CCTL1 0x06
+#define NPCM_I2CADDR1 0x08
+#define NPCM_I2CCTL2 0x0A
+#define NPCM_I2CADDR2 0x0C
+#define NPCM_I2CCTL3 0x0E
+#define NPCM_I2CCST2 0x18
+#define NPCM_I2CCST3 0x19
+#define I2C_VER 0x1F
+
+// BANK 0 regs
+#define NPCM_I2CADDR3 0x10
+#define NPCM_I2CADDR7 0x11
+#define NPCM_I2CADDR4 0x12
+#define NPCM_I2CADDR8 0x13
+#define NPCM_I2CADDR5 0x14
+#define NPCM_I2CADDR9 0x15
+#define NPCM_I2CADDR6 0x16
+#define NPCM_I2CADDR10 0x17
+
+#define NPCM_I2CCTL4 0x1A
+#define NPCM_I2CCTL5 0x1B
+#define NPCM_I2CSCLLT 0x1C // SCL Low Time
+#define NPCM_I2CFIF_CTL 0x1D // FIFO Control
+#define NPCM_I2CSCLHT 0x1E // SCL High Time
+
+// BANK 1 regs
+#define NPCM_I2CFIF_CTS 0x10 // Both FIFOs Control and status
+#define NPCM_I2CTXF_CTL 0x12 // Tx-FIFO Control
+#define NPCM_I2CT_OUT 0x14 // Bus T.O.
+#define NPCM_I2CPEC 0x16 // PEC Data
+#define NPCM_I2CTXF_STS 0x1A // Tx-FIFO Status
+#define NPCM_I2CRXF_STS 0x1C // Rx-FIFO Status
+#define NPCM_I2CRXF_CTL 0x1E // Rx-FIFO Control
+
+// NPCM_I2CST reg fields
+#define NPCM_I2CST_XMIT BIT(0)
+#define NPCM_I2CST_MASTER BIT(1)
+#define NPCM_I2CST_NMATCH BIT(2)
+#define NPCM_I2CST_STASTR BIT(3)
+#define NPCM_I2CST_NEGACK BIT(4)
+#define NPCM_I2CST_BER BIT(5)
+#define NPCM_I2CST_SDAST BIT(6)
+#define NPCM_I2CST_SLVSTP BIT(7)
+
+// NPCM_I2CCST reg fields
+#define NPCM_I2CCST_BUSY BIT(0)
+#define NPCM_I2CCST_BB BIT(1)
+#define NPCM_I2CCST_MATCH BIT(2)
+#define NPCM_I2CCST_GCMATCH BIT(3)
+#define NPCM_I2CCST_TSDA BIT(4)
+#define NPCM_I2CCST_TGSCL BIT(5)
+#define NPCM_I2CCST_MATCHAF BIT(6)
+#define NPCM_I2CCST_ARPMATCH BIT(7)
+
+// NPCM_I2CCTL1 reg fields
+#define NPCM_I2CCTL1_START BIT(0)
+#define NPCM_I2CCTL1_STOP BIT(1)
+#define NPCM_I2CCTL1_INTEN BIT(2)
+#define NPCM_I2CCTL1_EOBINTE BIT(3)
+#define NPCM_I2CCTL1_ACK BIT(4)
+#define NPCM_I2CCTL1_GCMEN BIT(5)
+#define NPCM_I2CCTL1_NMINTE BIT(6)
+#define NPCM_I2CCTL1_STASTRE BIT(7)
+
+// RW1S fields (inside a RW reg):
+#define NPCM_I2CCTL1_RWS_FIELDS (NPCM_I2CCTL1_START | NPCM_I2CCTL1_STOP | \
+ NPCM_I2CCTL1_ACK)
+
+// npcm_i2caddr reg fields
+#define NPCM_I2CADDR_A GENMASK(6, 0)
+#define NPCM_I2CADDR_SAEN BIT(7)
+
+// NPCM_I2CCTL2 reg fields
+#define I2CCTL2_ENABLE BIT(0)
+#define I2CCTL2_SCLFRQ6_0 GENMASK(7, 1)
+
+// NPCM_I2CCTL3 reg fields
+#define I2CCTL3_SCLFRQ8_7 GENMASK(1, 0)
+#define I2CCTL3_ARPMEN BIT(2)
+#define I2CCTL3_IDL_START BIT(3)
+#define I2CCTL3_400K_MODE BIT(4)
+#define I2CCTL3_BNK_SEL BIT(5)
+#define I2CCTL3_SDA_LVL BIT(6)
+#define I2CCTL3_SCL_LVL BIT(7)
+
+// NPCM_I2CCST2 reg fields
+#define NPCM_I2CCST2_MATCHA1F BIT(0)
+#define NPCM_I2CCST2_MATCHA2F BIT(1)
+#define NPCM_I2CCST2_MATCHA3F BIT(2)
+#define NPCM_I2CCST2_MATCHA4F BIT(3)
+#define NPCM_I2CCST2_MATCHA5F BIT(4)
+#define NPCM_I2CCST2_MATCHA6F BIT(5)
+#define NPCM_I2CCST2_MATCHA7F BIT(5)
+#define NPCM_I2CCST2_INTSTS BIT(7)
+
+// NPCM_I2CCST3 reg fields
+#define NPCM_I2CCST3_MATCHA8F BIT(0)
+#define NPCM_I2CCST3_MATCHA9F BIT(1)
+#define NPCM_I2CCST3_MATCHA10F BIT(2)
+#define NPCM_I2CCST3_EO_BUSY BIT(7)
+
+// NPCM_I2CCTL4 reg fields
+#define I2CCTL4_HLDT GENMASK(5, 0)
+#define I2CCTL4_LVL_WE BIT(7)
+
+// NPCM_I2CCTL5 reg fields
+#define I2CCTL5_DBNCT GENMASK(3, 0)
+
+// NPCM_I2CFIF_CTS reg fields
+#define NPCM_I2CFIF_CTS_RXF_TXE BIT(1)
+#define NPCM_I2CFIF_CTS_RFTE_IE BIT(3)
+#define NPCM_I2CFIF_CTS_CLR_FIFO BIT(6)
+#define NPCM_I2CFIF_CTS_SLVRSTR BIT(7)
+
+// NPCM_I2CTXF_CTL reg fields
+#define NPCM_I2CTXF_CTL_TX_THR GENMASK(4, 0)
+#define NPCM_I2CTXF_CTL_THR_TXIE BIT(6)
+
+// NPCM_I2CT_OUT reg fields
+#define NPCM_I2CT_OUT_TO_CKDIV GENMASK(5, 0)
+#define NPCM_I2CT_OUT_T_OUTIE BIT(6)
+#define NPCM_I2CT_OUT_T_OUTST BIT(7)
+
+// NPCM_I2CTXF_STS reg fields
+#define NPCM_I2CTXF_STS_TX_BYTES GENMASK(4, 0)
+#define NPCM_I2CTXF_STS_TX_THST BIT(6)
+
+// NPCM_I2CRXF_STS reg fields
+#define NPCM_I2CRXF_STS_RX_BYTES GENMASK(4, 0)
+#define NPCM_I2CRXF_STS_RX_THST BIT(6)
+
+// NPCM_I2CFIF_CTL reg fields
+#define NPCM_I2CFIF_CTL_FIFO_EN BIT(4)
+
+// NPCM_I2CRXF_CTL reg fields
+#define NPCM_I2CRXF_CTL_RX_THR GENMASK(4, 0)
+#define NPCM_I2CRXF_CTL_LAST_PEC BIT(5)
+#define NPCM_I2CRXF_CTL_THR_RXIE BIT(6)
+
+#define I2C_HW_FIFO_SIZE 16
+
+// I2C_VER reg fields
+#define I2C_VER_VERSION GENMASK(6, 0)
+#define I2C_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;
+
+// clk settings. values in KHZ.
+// The HW has different configuration modes per range
+// each range handled separetly
+const unsigned int I2C_FREQ_MIN = 10;
+const unsigned int I2C_FREQ_MAX = 1000;
+const unsigned int I2C_FREQ_100KHZ = 100;
+const unsigned int I2C_FREQ_400KHZ = 400;
+const unsigned int I2C_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 I2C_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 I2C 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 i2c_state state;
+ enum i2c_oper operation;
+ enum i2c_mode master_or_slave;
+ enum i2c_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;
+
+};
+
+static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
+ enum i2c_bank bank)
+{
+ if (bank == I2C_BANK_0)
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL3) & ~I2CCTL3_BNK_SEL,
+ bus->reg + NPCM_I2CCTL3);
+ else
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL3) | I2CCTL3_BNK_SEL,
+ bus->reg + NPCM_I2CCTL3);
+}
+
+static void npcm_i2c_init_params(struct npcm_i2c *bus)
+{
+ bus->stop_ind = I2C_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 = I2C_SLAVE;
+}
+
+static inline void npcm_i2c_wr_byte(struct npcm_i2c *bus, u8 data)
+{
+ iowrite8(data, bus->reg + NPCM_I2CSDA);
+}
+
+static inline void npcm_i2c_rd_byte(struct npcm_i2c *bus, u8 *data)
+{
+ *data = ioread8(bus->reg + NPCM_I2CSDA);
+}
+
+static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
+{
+ u16 index = 0;
+
+ if (bus->operation == I2C_READ_OPER)
+ index = bus->rd_ind;
+ else if (bus->operation == I2C_WRITE_OPER)
+ index = bus->wr_ind;
+
+ return index;
+}
+
+// quick protocol (just address):
+static inline bool npcm_i2c_is_quick(struct npcm_i2c *bus)
+{
+ if (bus->wr_size == 0 && bus->rd_size == 0)
+ return true;
+ return false;
+}
+
+static void npcm_i2c_disable(struct npcm_i2c *bus)
+{
+ int i;
+
+ // select bank 0 for I2C addresses
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ // Slave addresses removal
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OF_ADDR; i++)
+ iowrite8(0, bus->reg + npcm_i2caddr[i]);
+
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ // Disable module.
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL2) & ~I2CCTL2_ENABLE,
+ bus->reg + NPCM_I2CCTL2);
+
+ bus->state = I2C_DISABLE;
+}
+
+static void npcm_i2c_enable(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL2) | I2CCTL2_ENABLE),
+ bus->reg + NPCM_I2CCTL2);
+
+ bus->state = I2C_IDLE;
+}
+
+static bool npcm_i2c_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_I2CCST) & NPCM_I2CCST_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_i2c_eob_int(struct npcm_i2c *bus, bool enable)
+{
+ // Clear EO_BUSY pending bit:
+ iowrite8(ioread8(bus->reg + NPCM_I2CCST3) | NPCM_I2CCST3_EO_BUSY,
+ bus->reg + NPCM_I2CCST3);
+
+ if (enable) {
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
+ NPCM_I2CCTL1_EOBINTE) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ } else {
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_EOBINTE & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ }
+}
+
+static inline bool npcm_i2c_tx_fifo_empty(struct npcm_i2c *bus)
+{
+ u8 tx_fifo_sts = ioread8(bus->reg + NPCM_I2CTXF_STS);
+
+ // check if TX FIFO is not empty
+ if ((tx_fifo_sts & NPCM_I2CTXF_STS_TX_BYTES) == 0)
+ return false;
+
+ // check if TX FIFO status bit is set:
+ return (bool)FIELD_GET(NPCM_I2CTXF_STS_TX_THST, tx_fifo_sts);
+}
+
+static inline bool npcm_i2c_rx_fifo_full(struct npcm_i2c *bus)
+{
+ u8 rx_fifo_sts = ioread8(bus->reg + NPCM_I2CRXF_STS);
+
+ // check if RX FIFO is not empty:
+ if ((rx_fifo_sts & NPCM_I2CRXF_STS_RX_BYTES) == 0)
+ return false;
+
+ // check if rx fifo full status is set:
+ return (bool)FIELD_GET(NPCM_I2CRXF_STS_RX_THST, rx_fifo_sts);
+}
+
+static inline void npcm_i2c_clear_fifo_int(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_I2CFIF_CTS) &
+ NPCM_I2CFIF_CTS_SLVRSTR) |
+ NPCM_I2CFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_I2CFIF_CTS);
+}
+
+static inline void npcm_i2c_clear_tx_fifo(struct npcm_i2c *bus)
+{
+ iowrite8(ioread8(bus->reg + NPCM_I2CTXF_STS) | NPCM_I2CTXF_STS_TX_THST,
+ bus->reg + NPCM_I2CTXF_STS);
+}
+
+static inline void npcm_i2c_clear_rx_fifo(struct npcm_i2c *bus)
+{
+ iowrite8(ioread8(bus->reg + NPCM_I2CRXF_STS) | NPCM_I2CRXF_STS_RX_THST,
+ bus->reg + NPCM_I2CRXF_STS);
+}
+
+static void npcm_i2c_int_enable(struct npcm_i2c *bus, bool enable)
+{
+ if (enable)
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
+ NPCM_I2CCTL1_INTEN) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_INTEN) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static inline void npcm_i2c_master_start(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_START);
+
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_START) &
+ ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK),
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static inline void npcm_i2c_master_stop(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STOP);
+
+ // override HW issue: I2Cus 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_I2CCTL1) | NPCM_I2CCTL1_STOP) &
+ ~(NPCM_I2CCTL1_START | NPCM_I2CCTL1_ACK),
+ bus->reg + NPCM_I2CCTL1);
+
+ if (bus->fifo_use) {
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ if (bus->operation == I2C_READ_OPER)
+ npcm_i2c_clear_rx_fifo(bus);
+ else
+ npcm_i2c_clear_tx_fifo(bus);
+
+ npcm_i2c_clear_fifo_int(bus);
+
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ }
+}
+
+static inline void npcm_i2c_stall_after_start(struct npcm_i2c *bus, bool stall)
+{
+ if (stall)
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
+ NPCM_I2CCTL1_STASTRE) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_STASTRE) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static inline void npcm_i2c_nack(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_ACK) &
+ ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_START),
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static int npcm_i2c_slave_enable_l(struct npcm_i2c *bus,
+ enum i2c_addr addr_type, u8 addr,
+ bool enable);
+
+static void npcm_i2c_reset(struct npcm_i2c *bus)
+{
+ // Save NPCM_I2CCTL1 relevant bits. It is being cleared when the
+ // module is disabled
+ u8 i2cctl1;
+
+ i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
+
+ // Disable the I2C module
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL2) & ~I2CCTL2_ENABLE),
+ bus->reg + NPCM_I2CCTL2);
+
+ // Enable the I2C module
+ npcm_i2c_enable(bus);
+
+ // Restore NPCM_I2CCTL1 status
+ iowrite8(i2cctl1 & ~NPCM_I2CCTL1_RWS_FIELDS, bus->reg + NPCM_I2CCTL1);
+
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+
+ iowrite8(0xFF, bus->reg + NPCM_I2CST);
+
+ // Clear EOB bit
+ iowrite8(NPCM_I2CCST3_EO_BUSY, bus->reg + NPCM_I2CCST3);
+
+ // Clear all fifo bits:
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
+
+ bus->state = I2C_IDLE;
+}
+
+static inline bool npcm_i2c_is_master(struct npcm_i2c *bus)
+{
+ return (bool)FIELD_GET(NPCM_I2CST_MASTER,
+ ioread8(bus->reg + NPCM_I2CST));
+}
+
+static void npcm_i2c_callback(struct npcm_i2c *bus,
+ enum i2c_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 I2C_MASTER_DONE_IND:
+ bus->cmd_err = bus->msgs_num;
+ // fall through:
+ case I2C_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 I2C_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 == I2C_MASTER)
+ complete(&bus->cmd_complete);
+
+ break;
+ case I2C_BUS_ERR_IND:
+ // Bus error
+ bus->cmd_err = -EAGAIN;
+ if (bus->master_or_slave == I2C_MASTER)
+ complete(&bus->cmd_complete);
+
+ break;
+ case I2C_WAKE_UP_IND:
+ // I2Cus wake up
+ break;
+ default:
+ break;
+ }
+
+ bus->operation = I2C_NO_OPER;
+ if (bus->slave)
+ bus->master_or_slave = I2C_SLAVE;
+}
+
+static u32 npcm_i2c_get_fifo_fullness(struct npcm_i2c *bus)
+{
+ if (bus->operation == I2C_WRITE_OPER)
+ return FIELD_GET(NPCM_I2CTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_I2CTXF_STS));
+ else if (bus->operation == I2C_READ_OPER)
+ return FIELD_GET(NPCM_I2CRXF_STS_RX_BYTES,
+ ioread8(bus->reg + NPCM_I2CRXF_STS));
+ return 0;
+}
+
+static void npcm_i2c_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--) && (I2C_HW_FIFO_SIZE -
+ npcm_i2c_get_fifo_fullness(bus))) {
+ if (bus->wr_ind < bus->wr_size)
+ npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
+ else
+ npcm_i2c_wr_byte(bus, 0xFF);
+ }
+}
+
+// configure the FIFO before using it. If nread is -1 RX FIFO will not be
+// configured. same for nwrite
+static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
+{
+ u8 rxf_ctl = 0;
+
+ if (!bus->fifo_use)
+ return;
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+
+ // configure RX FIFO
+ if (nread > 0) {
+ rxf_ctl = min_t(u16, (u16)nread, (u16)I2C_HW_FIFO_SIZE);
+
+ // set LAST bit. if LAST is set enxt FIFO packet is nacked
+ // regular read of less then buffer size:
+ if (nread <= I2C_HW_FIFO_SIZE)
+ rxf_ctl |= NPCM_I2CRXF_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_I2CRXF_CTL);
+ }
+
+ // configure TX FIFO
+ if (nwrite > 0) {
+ if (nwrite > I2C_HW_FIFO_SIZE)
+ // data to send is more then FIFO size.
+ // Configure the FIFO int to be after of FIFO is cleared
+ iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CTXF_CTL);
+ else
+ iowrite8(nwrite, bus->reg + NPCM_I2CTXF_CTL);
+
+ npcm_i2c_clear_tx_fifo(bus);
+ }
+}
+
+static void npcm_i2c_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
+{
+ u8 data;
+
+ while (bytes_in_fifo--) {
+ npcm_i2c_rd_byte(bus, &data);
+
+ if (bus->master_or_slave == I2C_MASTER) {
+ if (bus->rd_ind < bus->rd_size)
+ bus->rd_buf[bus->rd_ind++] = data;
+ } else { // I2C_SLAVE:
+ }
+ }
+}
+
+static int npcm_i2c_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_i2c_is_master(bus)) {
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR,
+ bus->reg + NPCM_I2CST);
+ }
+
+ return ret;
+}
+
+static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
+{
+ int rcount;
+ int fifo_bytes;
+ enum i2c_state_ind ind = I2C_MASTER_DONE_IND;
+
+ fifo_bytes = npcm_i2c_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 * I2C_HW_FIFO_SIZE) && rcount > I2C_HW_FIFO_SIZE)
+ fifo_bytes = (u8)(rcount - I2C_HW_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 = I2C_STOP_PENDING;
+ bus->stop_ind = ind;
+
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+ npcm_i2c_read_from_fifo(bus, fifo_bytes);
+ } else {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ3);
+ npcm_i2c_read_from_fifo(bus, fifo_bytes);
+ rcount = bus->rd_size - bus->rd_ind;
+ npcm_i2c_set_fifo(bus, rcount, -1);
+ }
+}
+
+static void npcm_i2c_int_master_handler_write(struct npcm_i2c *bus)
+{
+ u16 wcount;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_WRITE);
+ if (bus->fifo_use)
+ npcm_i2c_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_i2c_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_i2c_eob_int(bus, true);
+
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = I2C_MASTER_DONE_IND;
+
+ npcm_i2c_master_stop(bus);
+ // Clear SDA Status bit (by writing dummy byte)
+ npcm_i2c_wr_byte(bus, 0xFF);
+
+ } else {
+ // last write-byte written on previous int - need to
+ // restart & send slave address
+ npcm_i2c_set_fifo(bus, bus->rd_size, -1);
+
+ // Generate repeated start upon next write to SDA
+ npcm_i2c_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_i2c_stall_after_start(bus, true);
+
+ // Next int will occur on read
+ bus->operation = I2C_READ_OPER;
+
+ // send the slave address in read direction
+ npcm_i2c_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_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
+ } else {
+ wcount = bus->wr_size - bus->wr_ind;
+ npcm_i2c_set_fifo(bus, -1, wcount);
+ npcm_i2c_write_to_fifo_master(bus, wcount);
+ }
+ }
+}
+
+static void npcm_i2c_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_i2c_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_I2CFIF_CTS_RXF_TXE |
+ ioread8(bus->reg + NPCM_I2CFIF_CTS),
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ npcm_i2c_set_fifo(bus, (bus->rd_size - 1), -1);
+ npcm_i2c_stall_after_start(bus, false);
+ } else {
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_master_fifo_read(bus);
+ }
+ } else {
+ if (bus->rd_size == block_extra_bytes_size &&
+ bus->read_block_use) {
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = I2C_BLOCK_BYTES_ERR_IND;
+ bus->cmd_err = -EIO;
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+ npcm_i2c_read_from_fifo(bus,
+ npcm_i2c_get_fifo_fullness(bus)
+ );
+ } else {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ2);
+ npcm_i2c_master_fifo_read(bus);
+ }
+ }
+}
+
+static irqreturn_t npcm_i2c_int_master_handler(struct npcm_i2c *bus)
+{
+ irqreturn_t ret = IRQ_NONE;
+ u8 fif_cts;
+
+ if (FIELD_GET(NPCM_I2CST_NMATCH, ioread8(bus->reg + NPCM_I2CST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_MSTR);
+ iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
+ npcm_i2c_nack(bus);
+ bus->stop_ind = I2C_BUS_ERR_IND;
+ npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus));
+
+ return IRQ_HANDLED;
+ }
+ // A NACK has occurred
+ if (FIELD_GET(NPCM_I2CST_NEGACK, ioread8(bus->reg + NPCM_I2CST))) {
+ 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 == I2C_WRITE_OPER)
+ bus->wr_ind -= npcm_i2c_get_fifo_fullness(bus);
+
+ // clear the FIFO
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ // In master write operation, NACK is a problem
+ // number of bytes sent to master less than required
+ bus->stop_ind = I2C_NACK_IND;
+ // Only current master is allowed to issue Stop Condition
+ if (npcm_i2c_is_master(bus)) {
+ // stopping in the middle, not waiting for ints anymore
+ npcm_i2c_eob_int(bus, false);
+
+ npcm_i2c_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_I2CST_BER | NPCM_I2CST_NEGACK |
+ NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
+
+ npcm_i2c_wait_for_bus_free(bus, false);
+ }
+ bus->state = I2C_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_i2c_callback(bus, bus->stop_ind, bus->wr_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Master mode: a Bus Error has been identified
+ if (FIELD_GET(NPCM_I2CST_BER, ioread8(bus->reg + NPCM_I2CST))) {
+ // 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 = I2C_BUS_ERR_IND;
+ if (npcm_i2c_is_master(bus)) {
+ npcm_i2c_master_abort(bus);
+ } else {
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_I2CST_BER | NPCM_I2CST_NEGACK |
+ NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
+
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+
+ bus->cmd_err = -EAGAIN;
+ npcm_i2c_callback(bus, bus->stop_ind,
+ npcm_i2c_get_index(bus));
+ }
+ bus->state = I2C_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_I2CCTL1_EOBINTE,
+ ioread8(bus->reg + NPCM_I2CCTL1)) == 1) &&
+ (FIELD_GET(NPCM_I2CCST3_EO_BUSY,
+ ioread8(bus->reg + NPCM_I2CCST3)))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_EOB);
+ npcm_i2c_eob_int(bus, false);
+ bus->state = I2C_IDLE;
+ npcm_i2c_callback(bus, bus->stop_ind, bus->rd_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Address sent and requested stall occurred (Master mode)
+ if (FIELD_GET(NPCM_I2CST_STASTR, ioread8(bus->reg + NPCM_I2CST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STALL);
+
+ if (npcm_i2c_is_quick(bus)) {
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = I2C_MASTER_DONE_IND;
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_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_i2c_nack(bus);
+ }
+
+ // Reset stall-after-address-byte
+ npcm_i2c_stall_after_start(bus, false);
+
+ // Clear stall only after setting STOP
+ iowrite8(NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // SDA status is set - TX or RX, master
+ if (FIELD_GET(NPCM_I2CST_SDAST, ioread8(bus->reg + NPCM_I2CST)) ||
+ (bus->fifo_use &&
+ (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
+ // Status Bit is cleared by writing to or reading from SDA
+ // (depending on current direction)
+
+ // Send address:
+ if (bus->state == I2C_IDLE) {
+ if (npcm_i2c_is_master(bus)) {
+ bus->stop_ind = I2C_WAKE_UP_IND;
+
+ // test stall on start
+ if (npcm_i2c_is_quick(bus) ||
+ bus->read_block_use)
+ // Need to stall after successful
+ // completion of sending address byte
+ npcm_i2c_stall_after_start(bus, true);
+ else
+ npcm_i2c_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_i2c_stall_after_start(bus, true);
+
+ // Initiate I2Cus master transaction
+ // Generate a Start condition on the I2Cus
+
+ // select bank 1 for FIFO regs
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR)
+ | NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ // and enable it
+ iowrite8((fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR)
+ | NPCM_I2CFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_I2CFIF_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_i2c_set_fifo(bus, -1,
+ bus->wr_size);
+ else
+ npcm_i2c_set_fifo(bus, bus->rd_size,
+ -1);
+
+ bus->state = I2C_OPER_STARTED;
+
+ if (npcm_i2c_is_quick(bus) || bus->wr_size)
+ npcm_i2c_wr_byte(bus, bus->dest_addr);
+ else
+ npcm_i2c_wr_byte(bus, bus->dest_addr |
+ 0x01);
+ }
+
+ return IRQ_HANDLED;
+ // SDA status is set - transmit or receive: Handle master mode
+ } else {
+ if ((NPCM_I2CST_XMIT &
+ ioread8(bus->reg + NPCM_I2CST)) == 0) {
+ bus->operation = I2C_READ_OPER;
+ npcm_i2c_int_master_handler_read(bus);
+ } else {
+ bus->operation = I2C_WRITE_OPER;
+ npcm_i2c_int_master_handler_write(bus);
+ }
+ }
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static int npcm_i2c_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(I2CCTL3_SCL_LVL, ioread32(bus->reg + NPCM_I2CCTL3));
+
+ pr_debug("i2c%d get SCL 0x%08X\n", bus->num, ret);
+
+ return (ret >> (offset)) & 0x01;
+}
+
+static int npcm_i2c_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(I2CCTL3_SDA_LVL, ioread32(bus->reg + NPCM_I2CCTL3));
+
+ 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_i2c_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);
+
+ if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1)) {
+ dev_dbg(bus->dev, "TGCLK recovery bus%d: skipped bus not stuck",
+ bus->num);
+ npcm_i2c_reset(bus);
+ return status;
+ }
+
+ // Disable int
+ npcm_i2c_int_enable(bus, false);
+
+ npcm_i2c_disable(bus);
+ npcm_i2c_enable(bus);
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ npcm_i2c_stall_after_start(bus, false);
+
+ // select bank 1 for FIFO regs
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR) |
+ NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ npcm_i2c_set_fifo(bus, -1, 0);
+
+ // Check If the SDA line is active (low)
+ if (npcm_i2c_get_SDA(_adap) == 0) {
+ // Repeat the following sequence until SDA is released
+ do {
+ // Issue a single SCL cycle
+ iowrite8(NPCM_I2CCST_TGSCL, bus->reg + NPCM_I2CCST);
+ retries = 10;
+ while (retries != 0 &&
+ FIELD_GET(NPCM_I2CCST_TGSCL,
+ ioread8(bus->reg + NPCM_I2CCST))) {
+ udelay(20);
+ retries--;
+ }
+
+ // tgclk failed to toggle
+ if (retries == 0)
+ dev_err(bus->dev, "recovery toggle timeout");
+ // If SDA line is inactive (high), stop
+ if (npcm_i2c_get_SDA(_adap))
+ done = true;
+ } while ((!done) && (--iter != 0));
+
+ // If SDA line is released: send start-addr-stop, to re-sync.
+ if (done) {
+ npcm_i2c_master_start(bus);
+
+ // Wait until START condition is sent, or RETRIES_NUM
+ retries = RETRIES_NUM;
+ while (retries && !npcm_i2c_is_master(bus)) {
+ udelay(20);
+ retries--;
+ }
+
+ // If START condition was sent
+ if (retries > 0) {
+ // Send an address byte in write direction:
+ npcm_i2c_wr_byte(bus, bus->dest_addr);
+ udelay(200);
+ npcm_i2c_master_stop(bus);
+ udelay(200);
+ status = 0;
+ }
+ }
+ }
+
+ // if bus is still stuck: total reset: set SCL low for 35ms:
+ if (unlikely(npcm_i2c_get_SDA(_adap) == 0)) {
+ // Generate a START, to synchronize Master and Slave
+ npcm_i2c_master_start(bus);
+
+ // Wait until START condition is sent, or RETRIES_NUM
+ retries = RETRIES_NUM;
+ while (retries && !npcm_i2c_is_master(bus))
+ retries--;
+
+ // set SCL low for a long time (note: this is unlikely)
+ usleep_range(25000, 35000);
+ npcm_i2c_master_stop(bus);
+ udelay(200);
+ status = 0;
+ }
+
+ dev_dbg(bus->dev, "recovery done, iter = %d, done = %d, retries = %d\n",
+ 27 - iter, done, retries);
+ // Enable I2C int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_NMINTE) &
+ ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ npcm_i2c_reset(bus);
+ npcm_i2c_int_enable(bus, true);
+ return status;
+}
+
+// recovery using bit banging functionality of the module
+static int npcm_i2c_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_i2c_recovery_tgclk;
+ rinfo->prepare_recovery = NULL;
+ rinfo->unprepare_recovery = NULL;
+ rinfo->set_scl = NULL;
+ rinfo->set_sda = NULL;
+
+ dev_dbg(bus->dev, "init i2c recovery using TGCLK\n");
+
+ rinfo->get_scl = npcm_i2c_get_SCL;
+ rinfo->get_sda = npcm_i2c_get_SDA;
+
+ _adap->bus_recovery_info = rinfo;
+
+ return 0;
+}
+
+static bool npcm_i2c_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 <= I2C_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 == I2C_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 == I2C_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(I2CCTL2_SCLFRQ6_0, sclfrq & 0x7F),
+ bus->reg + NPCM_I2CCTL2);
+
+ // force to bank 0, set SCL and fast mode
+ iowrite8(FIELD_PREP(I2CCTL3_400K_MODE, fast_mode) |
+ FIELD_PREP(I2CCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
+ bus->reg + NPCM_I2CCTL3);
+
+ // Select Bank 0 to access NPCM_I2CCTL4/NPCM_I2CCTL5
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ if (bus_freq >= I2C_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_I2CSCLLT);
+ iowrite8((u8)k2 / 2, bus->reg + NPCM_I2CSCLHT);
+
+ iowrite8(dbnct, bus->reg + NPCM_I2CCTL5);
+ }
+
+ iowrite8(hldt, bus->reg + NPCM_I2CCTL4);
+
+ // Return to Bank 1, and stay there by default:
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ return true;
+}
+
+static bool npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode,
+ u32 bus_freq)
+{
+ // Check whether module already enabled or frequency is out of bounds
+ if ((bus->state != I2C_DISABLE && bus->state != I2C_IDLE) ||
+ bus_freq < I2C_FREQ_MIN || bus_freq > I2C_FREQ_MAX)
+ return false;
+
+ npcm_i2c_disable(bus);
+
+ // Configure FIFO mode :
+ if (FIELD_GET(I2C_VER_FIFO_EN, ioread8(bus->reg + I2C_VER))) {
+ bus->fifo_use = true;
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+ iowrite8(ioread8(bus->reg + NPCM_I2CFIF_CTL) |
+ NPCM_I2CFIF_CTL_FIFO_EN, bus->reg + NPCM_I2CFIF_CTL);
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ } else {
+ bus->fifo_use = false;
+ }
+
+ // Configure I2C module clock frequency
+ if (!npcm_i2c_init_clk(bus, bus_freq)) {
+ dev_err(bus->dev, "npcm_i2c_init_clk failed\n");
+ return false;
+ }
+
+ // Enable module (before configuring CTL1)
+ npcm_i2c_enable(bus);
+ bus->state = I2C_IDLE;
+
+ // Enable I2C int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_NMINTE) &
+ ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+
+ npcm_i2c_int_enable(bus, true);
+
+ npcm_i2c_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 = I2C_DISABLE;
+ bus->master_or_slave = I2C_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_i2c_init_module(bus, I2C_MASTER, clk_freq / 1000);
+ if (!ret) {
+ dev_err(&pdev->dev, "npcm_i2c_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_i2c_is_master(bus))
+ bus->master_or_slave = I2C_MASTER;
+
+ if (bus->master_or_slave == I2C_MASTER) {
+ bus->int_time_stamp = jiffies;
+ ret = npcm_i2c_int_master_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+ return IRQ_HANDLED;
+}
+
+static bool npcm_i2c_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 != I2C_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 = I2C_READ_OPER;
+ else
+ bus->operation = I2C_WRITE_OPER;
+
+ bus->int_cnt = 0;
+ bus->event_log = 0;
+
+ if (bus->fifo_use) {
+ u8 i2cfif_cts;
+ // select bank 1 for FIFO regs
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ i2cfif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((i2cfif_cts & (~NPCM_I2CFIF_CTS_SLVRSTR)) |
+ NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ bus->state = I2C_IDLE;
+
+ npcm_i2c_stall_after_start(bus, true);
+ npcm_i2c_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 == I2C_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_I2CCST) & NPCM_I2CCST_BB;
+ if (!bus_busy && bus->slave)
+ iowrite8((bus->slave->addr & 0x7F),
+ bus->reg + NPCM_I2CADDR1);
+ spin_unlock_irqrestore(&bus->lock, flags);
+
+ if (!bus_busy)
+ break;
+ } while (time_is_after_jiffies(time_left));
+
+ if (bus_busy) {
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+ npcm_i2c_reset(bus);
+ i2c_recover_bus(adap);
+ return -EAGAIN;
+ }
+
+ npcm_i2c_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_i2c_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 == I2C_MASTER) {
+ dev_dbg(bus->dev,
+ "i2c%d TO = %d\n", bus->num, timeout);
+ i2c_recover_bus(adap);
+ bus->cmd_err = -EIO;
+ bus->state = I2C_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 nothing went wrong, return number of messages x-ferred.
+ if (ret >= 0)
+ return num;
+
+ 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_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,
+};
+
+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;
+ static struct regmap *gcr_regmap;
+ static struct regmap *clk_regmap;
+ int ret;
+ int num;
+
+ bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+ if (!bus)
+ return -ENOMEM;
+
+ bus->dev = &pdev->dev;
+
+#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);
+
+ // 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->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_i2c_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 %d is 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_i2c_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("0.1.1");
+
--
2.22.0
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