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Message-Id: <20240912-test-v1-15-458fa57c8ccf@analog.com>
Date: Thu, 12 Sep 2024 19:25:00 +0100
From: Arturs Artamonovs via B4 Relay <devnull+arturs.artamonovs.analog.com@...nel.org>
To: Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>, Greg Malysa <greg.malysa@...esys.com>,
Philipp Zabel <p.zabel@...gutronix.de>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Utsav Agarwal <Utsav.Agarwal@...log.com>,
Michael Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>, Linus Walleij <linus.walleij@...aro.org>,
Bartosz Golaszewski <brgl@...ev.pl>, Thomas Gleixner <tglx@...utronix.de>,
Andi Shyti <andi.shyti@...nel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Jiri Slaby <jirislaby@...nel.org>, Arnd Bergmann <arnd@...db.de>,
Olof Johansson <olof@...om.net>, soc@...nel.org
Cc: linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
devicetree@...r.kernel.org, linux-clk@...r.kernel.org,
linux-gpio@...r.kernel.org, linux-i2c@...r.kernel.org,
linux-serial@...r.kernel.org,
Arturs Artamonovs <arturs.artamonovs@...log.com>, adsp-linux@...log.com,
Arturs Artamonovs <Arturs.Artamonovs@...log.com>,
Nathan Barrett-Morrison <nathan.morrison@...esys.com>
Subject: [PATCH 15/21] i2c: Add driver for ADI ADSP-SC5xx platforms
From: Arturs Artamonovs <arturs.artamonovs@...log.com>
Add support for I2C on SC5xx
Signed-off-by: Arturs Artamonovs <Arturs.Artamonovs@...log.com>
Co-developed-by: Nathan Barrett-Morrison <nathan.morrison@...esys.com>
Signed-off-by: Nathan Barrett-Morrison <nathan.morrison@...esys.com>
Co-developed-by: Greg Malysa <greg.malysa@...esys.com>
Signed-off-by: Greg Malysa <greg.malysa@...esys.com>
---
drivers/i2c/busses/Kconfig | 17 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-adi-twi.c | 940 +++++++++++++++++++++++++++++++++++++++
3 files changed, 958 insertions(+)
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index a22f9125322a723b31925fd86b26ef0b8d3b8a19..f672a2c715ca15ece74ee694596318976da88dfd 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -518,6 +518,23 @@ config I2C_BRCMSTB
If you do not need I2C interface, say N.
+config I2C_ADI_TWI
+ tristate "ADI TWI I2C support"
+ depends on ARCH_SC59X_64 || ARCH_SC59X
+ help
+ This is the I2C bus driver for ADI on-chip TWI interface.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-adi-twi.
+
+config I2C_ADI_TWI_CLK_KHZ
+ int "ADI TWI I2C clock (kHz)"
+ depends on I2C_ADI_TWI
+ range 21 400
+ default 50
+ help
+ The unit of the TWI clock is kHz.
+
config I2C_CADENCE
tristate "Cadence I2C Controller"
depends on ARCH_ZYNQ || ARM64 || XTENSA || RISCV || COMPILE_TEST
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 78d0561339e5beadcb810196be1139a4248469b4..421d637cfbc91af5a69895e76a255b2ef47f4081 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
obj-$(CONFIG_I2C_AXXIA) += i2c-axxia.o
obj-$(CONFIG_I2C_BCM2835) += i2c-bcm2835.o
obj-$(CONFIG_I2C_BCM_IPROC) += i2c-bcm-iproc.o
+obj-$(CONFIG_I2C_ADI_TWI) += i2c-adi-twi.o
obj-$(CONFIG_I2C_CADENCE) += i2c-cadence.o
obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o
obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
diff --git a/drivers/i2c/busses/i2c-adi-twi.c b/drivers/i2c/busses/i2c-adi-twi.c
new file mode 100644
index 0000000000000000000000000000000000000000..4af3991f5fc8709df196f58816ed7a96fd1dac2d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-adi-twi.c
@@ -0,0 +1,940 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ADI On-Chip Two Wire Interface Driver
+ *
+ * Copyright 2022-2024 - Analog Devices Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/of_device.h>
+#include <linux/clk.h>
+
+
+/* TWI_PRESCALE Masks */
+#define TWI_ENA 0x0080 /* TWI Enable */
+
+/* TWI_MASTER_CTL Masks */
+#define MEN 0x0001 /* Master Mode Enable */
+#define MDIR 0x0004 /* Master Transmit Direction (RX/TX*) */
+#define FAST 0x0008 /* Use Fast Mode Timing Specs */
+#define STOP 0x0010 /* Issue Stop Condition */
+#define RSTART 0x0020 /* Repeat Start or Stop* At End Of Transfer */
+#define SDAOVR 0x4000 /* Serial Data Override */
+#define SCLOVR 0x8000 /* Serial Clock Override */
+
+/* TWI_MASTER_STAT Masks */
+#define LOSTARB 0x0002 /* Lost Arbitration Indicator (Xfer Aborted) */
+#define ANAK 0x0004 /* Address Not Acknowledged */
+#define DNAK 0x0008 /* Data Not Acknowledged */
+#define BUFRDERR 0x0010 /* Buffer Read Error */
+#define BUFWRERR 0x0020 /* Buffer Write Error */
+#define SDASEN 0x0040 /* Serial Data Sense */
+#define BUSBUSY 0x0100 /* Bus Busy Indicator */
+
+/* TWI_INT_SRC and TWI_INT_ENABLE Masks */
+#define MCOMP 0x0010 /* Master Transfer Complete */
+#define MERR 0x0020 /* Master Transfer Error */
+#define XMTSERV 0x0040 /* Transmit FIFO Service */
+#define RCVSERV 0x0080 /* Receive FIFO Service */
+
+/* TWI_FIFO_STAT Masks */
+#define XMTSTAT 0x0003 /* Transmit FIFO Status */
+#define XMT_FULL 0x0003 /* Transmit FIFO Full (2 Bytes To Write) */
+#define RCVSTAT 0x000C /* Receive FIFO Status */
+
+/* SMBus mode*/
+#define TWI_I2C_MODE_STANDARD 1
+#define TWI_I2C_MODE_STANDARDSUB 2
+#define TWI_I2C_MODE_COMBINED 3
+#define TWI_I2C_MODE_REPEAT 4
+
+/*
+ * ADI twi registers layout
+ */
+struct adi_twi_regs {
+ u16 clkdiv;
+ u16 dummy1;
+ u16 control;
+ u16 dummy2;
+ u16 slave_ctl;
+ u16 dummy3;
+ u16 slave_stat;
+ u16 dummy4;
+ u16 slave_addr;
+ u16 dummy5;
+ u16 master_ctl;
+ u16 dummy6;
+ u16 master_stat;
+ u16 dummy7;
+ u16 master_addr;
+ u16 dummy8;
+ u16 int_stat;
+ u16 dummy9;
+ u16 int_mask;
+ u16 dummy10;
+ u16 fifo_ctl;
+ u16 dummy11;
+ u16 fifo_stat;
+ u16 dummy12;
+ u32 __pad[20];
+ u16 xmt_data8;
+ u16 dummy13;
+ u16 xmt_data16;
+ u16 dummy14;
+ u16 rcv_data8;
+ u16 dummy15;
+ u16 rcv_data16;
+ u16 dummy16;
+};
+
+struct adi_twi_iface {
+ int irq;
+ spinlock_t lock;
+ char read_write;
+ u8 command;
+ u8 *transPtr;
+ int readNum;
+ int writeNum;
+ int cur_mode;
+ int manual_stop;
+ int result;
+ unsigned int twi_clk;
+ struct i2c_adapter adap;
+ struct completion complete;
+ struct i2c_msg *pmsg;
+ int msg_num;
+ int cur_msg;
+ u16 saved_clkdiv;
+ u16 saved_control;
+ struct adi_twi_regs __iomem *regs_base;
+ struct clk *sclk;
+};
+
+static void adi_twi_handle_interrupt(struct adi_twi_iface *iface,
+ unsigned short twi_int_status,
+ bool polling)
+{
+ u16 writeValue;
+ unsigned short mast_stat = ioread16(&iface->regs_base->master_stat);
+
+ if (twi_int_status & XMTSERV) {
+ if (iface->writeNum <= 0) {
+ /* start receive immediately after complete sending in
+ * combine mode.
+ */
+ if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
+ writeValue = ioread16(&iface->regs_base->master_ctl) | MDIR;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else if (iface->manual_stop) {
+ writeValue = ioread16(&iface->regs_base->master_ctl) | STOP;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
+ iface->cur_msg + 1 < iface->msg_num) {
+
+ if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD) {
+ writeValue = ioread16(&iface->regs_base->master_ctl)
+ | MDIR;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else {
+ writeValue = ioread16(&iface->regs_base->master_ctl)
+ & ~MDIR;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ }
+
+ }
+ }
+ /* Transmit next data */
+ while (iface->writeNum > 0 &&
+ (ioread16(&iface->regs_base->fifo_stat) & XMTSTAT) != XMT_FULL) {
+ iowrite16(*(iface->transPtr++), &iface->regs_base->xmt_data8);
+ iface->writeNum--;
+ }
+ }
+ if (twi_int_status & RCVSERV) {
+ while (iface->readNum > 0 &&
+ (ioread16(&iface->regs_base->fifo_stat) & RCVSTAT)) {
+ /* Receive next data */
+ *(iface->transPtr) = ioread16(&iface->regs_base->rcv_data8);
+ if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
+ /* Change combine mode into sub mode after
+ * read first data.
+ */
+ iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
+ /* Get read number from first byte in block
+ * combine mode.
+ */
+ if (iface->readNum == 1 && iface->manual_stop)
+ iface->readNum = *iface->transPtr + 1;
+ }
+ iface->transPtr++;
+ iface->readNum--;
+ }
+
+ if (iface->readNum == 0) {
+ if (iface->manual_stop) {
+ /* Temporary workaround to avoid possible bus stall -
+ * Flush FIFO before issuing the STOP condition
+ */
+ ioread16(&iface->regs_base->rcv_data16);
+ writeValue = ioread16(&iface->regs_base->master_ctl) | STOP;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
+ iface->cur_msg + 1 < iface->msg_num) {
+ if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD) {
+ writeValue = ioread16(&iface->regs_base->master_ctl) |
+ MDIR;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else {
+ writeValue = ioread16(&iface->regs_base->master_ctl) &
+ ~MDIR;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ }
+ }
+ }
+ }
+ if (twi_int_status & MERR) {
+ iowrite16(0, &iface->regs_base->int_mask);
+ iowrite16(0x3e, &iface->regs_base->master_stat);
+ iowrite16(0, &iface->regs_base->master_ctl);
+ iface->result = -EIO;
+
+ if (mast_stat & LOSTARB)
+ dev_dbg(&iface->adap.dev, "Lost Arbitration\n");
+ if (mast_stat & ANAK)
+ dev_dbg(&iface->adap.dev, "Address Not Acknowledged\n");
+ if (mast_stat & DNAK)
+ dev_dbg(&iface->adap.dev, "Data Not Acknowledged\n");
+ if (mast_stat & BUFRDERR)
+ dev_dbg(&iface->adap.dev, "Buffer Read Error\n");
+ if (mast_stat & BUFWRERR)
+ dev_dbg(&iface->adap.dev, "Buffer Write Error\n");
+
+ /* Faulty slave devices, may drive SDA low after a transfer
+ * finishes. To release the bus this code generates up to 9
+ * extra clocks until SDA is released.
+ */
+
+ if (ioread16(&iface->regs_base->master_stat) & SDASEN) {
+ int cnt = 9;
+
+ do {
+ iowrite16(SCLOVR, &iface->regs_base->master_ctl);
+ udelay(6);
+ iowrite16(0, &iface->regs_base->master_ctl);
+ udelay(6);
+ } while ((ioread16(&iface->regs_base->master_stat) & SDASEN) && cnt--);
+
+ iowrite16(SDAOVR | SCLOVR, &iface->regs_base->master_ctl);
+ udelay(6);
+ iowrite16(SDAOVR, &iface->regs_base->master_ctl);
+ udelay(6);
+ iowrite16(0, &iface->regs_base->master_ctl);
+ }
+
+ /* If it is a quick transfer, only address without data,
+ * not an err, return 1.
+ */
+ if (iface->cur_mode == TWI_I2C_MODE_STANDARD &&
+ iface->transPtr == NULL &&
+ (twi_int_status & MCOMP) && (mast_stat & DNAK))
+ iface->result = 1;
+
+ if (!polling)
+ complete(&iface->complete);
+ return;
+ }
+ if (twi_int_status & MCOMP) {
+ if (twi_int_status & (XMTSERV | RCVSERV) &&
+ (ioread16(&iface->regs_base->master_ctl) & MEN) == 0 &&
+ (iface->cur_mode == TWI_I2C_MODE_REPEAT ||
+ iface->cur_mode == TWI_I2C_MODE_COMBINED)) {
+ iface->result = -1;
+ iowrite16(0, &iface->regs_base->int_mask);
+ iowrite16(0, &iface->regs_base->master_ctl);
+ } else if (iface->cur_mode == TWI_I2C_MODE_COMBINED) {
+ if (iface->readNum == 0) {
+ /* set the read number to 1 and ask for manual
+ * stop in block combine mode
+ */
+ iface->readNum = 1;
+ iface->manual_stop = 1;
+ writeValue = ioread16(&iface->regs_base->master_ctl) | (0xff << 6);
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else {
+ /* set the readd number in other
+ * combine mode.
+ */
+ writeValue = (ioread16(&iface->regs_base->master_ctl)
+ & (~(0xff << 6))) | (iface->readNum << 6);
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ }
+ /* remove restart bit and enable master receive */
+ writeValue = ioread16(&iface->regs_base->master_ctl) & ~RSTART;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ } else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
+ iface->cur_msg + 1 < iface->msg_num) {
+ iface->cur_msg++;
+ iface->transPtr = iface->pmsg[iface->cur_msg].buf;
+ iface->writeNum = iface->readNum =
+ iface->pmsg[iface->cur_msg].len;
+ /* Set Transmit device address */
+ iowrite16(iface->pmsg[iface->cur_msg].addr, &iface->regs_base->master_addr);
+ if (iface->pmsg[iface->cur_msg].flags & I2C_M_RD)
+ iface->read_write = I2C_SMBUS_READ;
+ else {
+ iface->read_write = I2C_SMBUS_WRITE;
+ /* Transmit first data */
+ if (iface->writeNum > 0) {
+ iowrite16(*(iface->transPtr++),
+ &iface->regs_base->xmt_data8);
+ iface->writeNum--;
+ }
+ }
+
+ if (iface->pmsg[iface->cur_msg].len <= 255) {
+ writeValue = (ioread16(&iface->regs_base->master_ctl)
+ & (~(0xff << 6)))
+ | (iface->pmsg[iface->cur_msg].len << 6);
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ iface->manual_stop = 0;
+ } else {
+ writeValue = (ioread16(&iface->regs_base->master_ctl)
+ | (0xff << 6));
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ iface->manual_stop = 1;
+ }
+
+ /* remove restart bit before last message */
+ if (iface->cur_msg + 1 == iface->msg_num) {
+ writeValue = ioread16(&iface->regs_base->master_ctl) & ~RSTART;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ }
+
+ } else {
+ iface->result = 1;
+ iowrite16(0, &iface->regs_base->int_mask);
+ iowrite16(0, &iface->regs_base->master_ctl);
+ }
+ if (!polling)
+ complete(&iface->complete);
+ }
+}
+
+/* Interrupt handler */
+static irqreturn_t adi_twi_handle_all_interrupts(struct adi_twi_iface *iface,
+ bool polling)
+{
+ irqreturn_t handled = IRQ_NONE;
+ unsigned short twi_int_status;
+
+ while (1) {
+ twi_int_status = ioread16(&iface->regs_base->int_stat);
+ if (!twi_int_status)
+ return handled;
+ /* Clear interrupt status */
+ iowrite16(twi_int_status, &iface->regs_base->int_stat);
+ adi_twi_handle_interrupt(iface, twi_int_status, polling);
+ handled = IRQ_HANDLED;
+ }
+}
+
+static irqreturn_t adi_twi_interrupt_entry(int irq, void *dev_id)
+{
+ struct adi_twi_iface *iface = dev_id;
+ unsigned long flags;
+ irqreturn_t handled;
+
+ spin_lock_irqsave(&iface->lock, flags);
+ handled = adi_twi_handle_all_interrupts(iface, false);
+ spin_unlock_irqrestore(&iface->lock, flags);
+ return handled;
+}
+
+/*
+ * One i2c master transfer
+ */
+static int adi_twi_do_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num, bool polling)
+{
+ struct adi_twi_iface *iface = adap->algo_data;
+ struct i2c_msg *pmsg;
+ int rc = 0;
+ u16 writeValue;
+
+ if (!(ioread16(&iface->regs_base->control) & TWI_ENA))
+ return -ENXIO;
+
+ if (ioread16(&iface->regs_base->master_stat) & BUSBUSY)
+ return -EAGAIN;
+
+ iface->pmsg = msgs;
+ iface->msg_num = num;
+ iface->cur_msg = 0;
+
+ pmsg = &msgs[0];
+ if (pmsg->flags & I2C_M_TEN) {
+ dev_err(&adap->dev, "10 bits addr not supported!\n");
+ return -EINVAL;
+ }
+
+ if (iface->msg_num > 1)
+ iface->cur_mode = TWI_I2C_MODE_REPEAT;
+ iface->manual_stop = 0;
+ iface->transPtr = pmsg->buf;
+ iface->writeNum = iface->readNum = pmsg->len;
+ iface->result = 0;
+ if (!polling)
+ init_completion(&(iface->complete));
+ /* Set Transmit device address */
+ iowrite16(pmsg->addr, &iface->regs_base->master_addr);
+
+ /* FIFO Initiation. Data in FIFO should be
+ * discarded before start a new operation.
+ */
+ iowrite16(0x3, &iface->regs_base->fifo_ctl);
+ iowrite16(0, &iface->regs_base->fifo_ctl);
+
+ if (pmsg->flags & I2C_M_RD)
+ iface->read_write = I2C_SMBUS_READ;
+ else {
+ iface->read_write = I2C_SMBUS_WRITE;
+ /* Transmit first data */
+ if (iface->writeNum > 0) {
+ iowrite16(*(iface->transPtr++), &iface->regs_base->xmt_data8);
+ iface->writeNum--;
+ }
+ }
+
+ /* clear int stat */
+ iowrite16(MERR | MCOMP | XMTSERV | RCVSERV, &iface->regs_base->int_stat);
+
+ /* Interrupt mask . Enable XMT, RCV interrupt */
+ iowrite16(MCOMP | MERR | RCVSERV | XMTSERV, &iface->regs_base->int_mask);
+
+ if (pmsg->len <= 255)
+ iowrite16(pmsg->len << 6, &iface->regs_base->master_ctl);
+ else {
+ iowrite16(0xff << 6, &iface->regs_base->master_ctl);
+ iface->manual_stop = 1;
+ }
+
+ /* Master enable */
+ writeValue = ioread16(&iface->regs_base->master_ctl) |
+ MEN |
+ ((iface->msg_num > 1) ? RSTART : 0) |
+ ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
+ ((iface->twi_clk > 100) ? FAST : 0);
+
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+
+ if (polling) {
+ int timeout = 50000;
+
+ for (;;) {
+ irqreturn_t handled = adi_twi_handle_all_interrupts(
+ iface, true);
+ if (handled == IRQ_HANDLED && iface->result)
+ break;
+ if (--timeout == 0) {
+ iface->result = -1;
+ dev_err(&adap->dev, "master polling timeout");
+ break;
+ }
+ }
+ } else { /* interrupt driven */
+ while (!iface->result) {
+ if (!wait_for_completion_timeout(&iface->complete,
+ adap->timeout)) {
+ iface->result = -1;
+ dev_err(&adap->dev, "master transfer timeout");
+ }
+ }
+ }
+
+ if (iface->result == 1)
+ rc = iface->cur_msg + 1;
+ else
+ rc = iface->result;
+
+ return rc;
+}
+
+/*
+ * Generic i2c master transfer entrypoint
+ */
+static int adi_twi_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ return adi_twi_do_master_xfer(adap, msgs, num, false);
+}
+
+static int adi_twi_master_xfer_atomic(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ return adi_twi_do_master_xfer(adap, msgs, num, true);
+}
+
+/*
+ * One I2C SMBus transfer
+ */
+static int adi_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data,
+ bool polling)
+{
+ struct adi_twi_iface *iface = adap->algo_data;
+ int rc = 0;
+ u16 writeValue;
+
+ if (!(ioread16(&iface->regs_base->control) & TWI_ENA))
+ return -ENXIO;
+
+ if (ioread16(&iface->regs_base->master_stat) & BUSBUSY)
+ return -EAGAIN;
+
+ iface->writeNum = 0;
+ iface->readNum = 0;
+
+ /* Prepare datas & select mode */
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ iface->transPtr = NULL;
+ iface->cur_mode = TWI_I2C_MODE_STANDARD;
+ break;
+ case I2C_SMBUS_BYTE:
+ if (data == NULL)
+ iface->transPtr = NULL;
+ else {
+ if (read_write == I2C_SMBUS_READ)
+ iface->readNum = 1;
+ else
+ iface->writeNum = 1;
+ iface->transPtr = &data->byte;
+ }
+ iface->cur_mode = TWI_I2C_MODE_STANDARD;
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ if (read_write == I2C_SMBUS_READ) {
+ iface->readNum = 1;
+ iface->cur_mode = TWI_I2C_MODE_COMBINED;
+ } else {
+ iface->writeNum = 1;
+ iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
+ }
+ iface->transPtr = &data->byte;
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ if (read_write == I2C_SMBUS_READ) {
+ iface->readNum = 2;
+ iface->cur_mode = TWI_I2C_MODE_COMBINED;
+ } else {
+ iface->writeNum = 2;
+ iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
+ }
+ iface->transPtr = (u8 *)&data->word;
+ break;
+ case I2C_SMBUS_PROC_CALL:
+ iface->writeNum = 2;
+ iface->readNum = 2;
+ iface->cur_mode = TWI_I2C_MODE_COMBINED;
+ iface->transPtr = (u8 *)&data->word;
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ if (read_write == I2C_SMBUS_READ) {
+ iface->readNum = 0;
+ iface->cur_mode = TWI_I2C_MODE_COMBINED;
+ } else {
+ iface->writeNum = data->block[0] + 1;
+ iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
+ }
+ iface->transPtr = data->block;
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ if (read_write == I2C_SMBUS_READ) {
+ iface->readNum = data->block[0];
+ iface->cur_mode = TWI_I2C_MODE_COMBINED;
+ } else {
+ iface->writeNum = data->block[0];
+ iface->cur_mode = TWI_I2C_MODE_STANDARDSUB;
+ }
+ iface->transPtr = (u8 *)&data->block[1];
+ break;
+ default:
+ return -1;
+ }
+
+ iface->result = 0;
+ iface->manual_stop = 0;
+ iface->read_write = read_write;
+ iface->command = command;
+ if (!polling)
+ init_completion(&(iface->complete));
+
+ /* FIFO Initiation. Data in FIFO should be discarded before
+ * start a new operation.
+ */
+ iowrite16(0x3, &iface->regs_base->fifo_ctl);
+ iowrite16(0, &iface->regs_base->fifo_ctl);
+
+ /* clear int stat */
+ iowrite16(MERR | MCOMP | XMTSERV | RCVSERV, &iface->regs_base->int_stat);
+
+ /* Set Transmit device address */
+ iowrite16(addr, &iface->regs_base->master_addr);
+
+ switch (iface->cur_mode) {
+ case TWI_I2C_MODE_STANDARDSUB:
+ iowrite16(iface->command, &iface->regs_base->xmt_data8);
+
+ writeValue = MCOMP | MERR;
+ if (iface->read_write == I2C_SMBUS_READ)
+ writeValue |= RCVSERV;
+ else
+ writeValue |= XMTSERV;
+
+ iowrite16(writeValue, &iface->regs_base->int_mask);
+
+ if (iface->writeNum + 1 <= 255)
+ iowrite16((iface->writeNum + 1) << 6, &iface->regs_base->master_ctl);
+ else {
+ iowrite16(0xff << 6, &iface->regs_base->master_ctl);
+ iface->manual_stop = 1;
+ }
+ /* Master enable */
+ writeValue = ioread16(&iface->regs_base->master_ctl) | MEN;
+ if (iface->twi_clk > 100)
+ writeValue |= FAST;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ break;
+ case TWI_I2C_MODE_COMBINED:
+ iowrite16(iface->command, &iface->regs_base->xmt_data8);
+ iowrite16(MCOMP | MERR | RCVSERV | XMTSERV, &iface->regs_base->int_mask);
+
+ if (iface->writeNum > 0)
+ iowrite16((iface->writeNum + 1) << 6, &iface->regs_base->master_ctl);
+ else
+ iowrite16(0x1 << 6, &iface->regs_base->master_ctl);
+ /* Master enable */
+ writeValue = ioread16(&iface->regs_base->master_ctl) | MEN | RSTART;
+ if (iface->twi_clk > 100)
+ writeValue |= FAST;
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ break;
+ default:
+ iowrite16(0, &iface->regs_base->master_ctl);
+ if (size != I2C_SMBUS_QUICK) {
+ /* Don't access xmit data register when this is a
+ * read operation.
+ */
+ if (iface->read_write != I2C_SMBUS_READ) {
+ if (iface->writeNum > 0) {
+ iowrite16(*(iface->transPtr++),
+ &iface->regs_base->xmt_data8);
+ if (iface->writeNum <= 255)
+ iowrite16(iface->writeNum << 6,
+ &iface->regs_base->master_ctl);
+ else {
+ iowrite16(0xff << 6, &iface->regs_base->master_ctl);
+ iface->manual_stop = 1;
+ }
+ iface->writeNum--;
+ } else {
+ iowrite16(iface->command, &iface->regs_base->xmt_data8);
+ iowrite16(1 << 6, &iface->regs_base->master_ctl);
+ }
+ } else {
+ if (iface->readNum > 0 && iface->readNum <= 255)
+ iowrite16(iface->readNum << 6,
+ &iface->regs_base->master_ctl);
+ else if (iface->readNum > 255) {
+ iowrite16(0xff << 6, &iface->regs_base->master_ctl);
+ iface->manual_stop = 1;
+ } else
+ break;
+ }
+ }
+ writeValue = MCOMP | MERR;
+ if (iface->read_write == I2C_SMBUS_READ)
+ writeValue |= RCVSERV;
+ else
+ writeValue |= XMTSERV;
+ iowrite16(writeValue, &iface->regs_base->int_mask);
+
+ /* Master enable */
+ writeValue = ioread16(&iface->regs_base->master_ctl) | MEN |
+ ((iface->read_write == I2C_SMBUS_READ) ? MDIR : 0) |
+ ((iface->twi_clk > 100) ? FAST : 0);
+ iowrite16(writeValue, &iface->regs_base->master_ctl);
+ break;
+ }
+
+ if (polling) {
+ int timeout = 50000;
+
+ for (;;) {
+ irqreturn_t handled = adi_twi_handle_all_interrupts(
+ iface, true);
+ if (handled == IRQ_HANDLED && iface->result)
+ break;
+ if (--timeout == 0) {
+ iface->result = -1;
+ dev_err(&adap->dev, "smbus polling timeout");
+ break;
+ }
+ }
+ } else { /* interrupt driven */
+ while (!iface->result) {
+ if (!wait_for_completion_timeout(&iface->complete,
+ adap->timeout)) {
+ iface->result = -1;
+ dev_err(&adap->dev, "smbus transfer timeout");
+ }
+ }
+ }
+
+ rc = (iface->result >= 0) ? 0 : -1;
+
+ return rc;
+}
+
+/*
+ * Generic I2C SMBus transfer entrypoint
+ */
+static int adi_twi_smbus_xfer(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data)
+{
+ return adi_twi_do_smbus_xfer(adap, addr, flags,
+ read_write, command, size, data, false);
+}
+
+static int adi_twi_smbus_xfer_atomic(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data)
+{
+ return adi_twi_do_smbus_xfer(adap, addr, flags,
+ read_write, command, size, data, true);
+}
+
+/*
+ * Return what the adapter supports
+ */
+static u32 adi_twi_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
+ I2C_FUNC_I2C | I2C_FUNC_SMBUS_I2C_BLOCK;
+}
+
+static const struct i2c_algorithm adi_twi_algorithm = {
+ .master_xfer = adi_twi_master_xfer,
+ .master_xfer_atomic = adi_twi_master_xfer_atomic,
+ .smbus_xfer = adi_twi_smbus_xfer,
+ .smbus_xfer_atomic = adi_twi_smbus_xfer_atomic,
+ .functionality = adi_twi_functionality,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int i2c_adi_twi_suspend(struct device *dev)
+{
+ struct adi_twi_iface *iface = dev_get_drvdata(dev);
+
+ iface->saved_clkdiv = ioread16(&iface->regs_base->clkdiv);
+ iface->saved_control = ioread16(&iface->regs_base->control);
+
+ free_irq(iface->irq, iface);
+
+ /* Disable TWI */
+ iowrite16(iface->saved_control & ~TWI_ENA, &iface->regs_base->control);
+
+ return 0;
+}
+
+static int i2c_adi_twi_resume(struct device *dev)
+{
+ struct adi_twi_iface *iface = dev_get_drvdata(dev);
+
+ int rc = request_irq(iface->irq, adi_twi_interrupt_entry,
+ 0, to_platform_device(dev)->name, iface);
+ if (rc) {
+ dev_err(dev, "Can't get IRQ %d !\n", iface->irq);
+ return -ENODEV;
+ }
+
+ /* Resume TWI interface clock as specified */
+ iowrite16(iface->saved_clkdiv, &iface->regs_base->clkdiv);
+
+ /* Resume TWI */
+ iowrite16(iface->saved_control, &iface->regs_base->control);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(i2c_adi_twi_pm,
+ i2c_adi_twi_suspend, i2c_adi_twi_resume);
+#define I2C_ADI_TWI_PM_OPS (&i2c_adi_twi_pm)
+#else
+#define I2C_ADI_TWI_PM_OPS NULL
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id adi_twi_of_match[] = {
+ {
+ .compatible = "adi,twi",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, adi_twi_of_match);
+#endif
+
+static int i2c_adi_twi_probe(struct platform_device *pdev)
+{
+ struct adi_twi_iface *iface;
+ struct i2c_adapter *p_adap;
+ struct resource *res;
+ const struct of_device_id *match;
+ struct device_node *node = pdev->dev.of_node;
+ int rc;
+ unsigned int clkhilow;
+ u16 writeValue;
+
+ iface = devm_kzalloc(&pdev->dev, sizeof(*iface), GFP_KERNEL);
+ if (!iface)
+ return -ENOMEM;
+
+ spin_lock_init(&(iface->lock));
+
+ match = of_match_device(of_match_ptr(adi_twi_of_match), &pdev->dev);
+ if (match) {
+ if (of_property_read_u32(node, "clock-khz",
+ &iface->twi_clk))
+ iface->twi_clk = 50;
+ } else
+ iface->twi_clk = CONFIG_I2C_ADI_TWI_CLK_KHZ;
+
+ iface->sclk = devm_clk_get(&pdev->dev, "sclk0");
+ if (IS_ERR(iface->sclk)) {
+ if (PTR_ERR(iface->sclk) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "Missing i2c clock\n");
+ return PTR_ERR(iface->sclk);
+ }
+
+ /* Find and map our resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL) {
+ dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
+ return -ENOENT;
+ }
+
+ iface->regs_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(iface->regs_base)) {
+ dev_err(&pdev->dev, "Cannot map IO\n");
+ return PTR_ERR(iface->regs_base);
+ }
+
+ iface->irq = platform_get_irq(pdev, 0);
+ if (iface->irq < 0) {
+ dev_err(&pdev->dev, "No IRQ specified\n");
+ return -ENOENT;
+ }
+
+ p_adap = &iface->adap;
+ p_adap->nr = pdev->id;
+ strscpy(p_adap->name, pdev->name, sizeof(p_adap->name));
+ p_adap->algo = &adi_twi_algorithm;
+ p_adap->algo_data = iface;
+ p_adap->class = I2C_CLASS_DEPRECATED;
+ p_adap->dev.parent = &pdev->dev;
+ p_adap->dev.of_node = node;
+ p_adap->timeout = 5 * HZ;
+ p_adap->retries = 3;
+
+ rc = devm_request_irq(&pdev->dev, iface->irq, adi_twi_interrupt_entry,
+ 0, pdev->name, iface);
+ if (rc) {
+ dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
+ rc = -ENODEV;
+ goto out_error;
+ }
+
+ /* Set TWI internal clock as 10MHz */
+ clk_prepare_enable(iface->sclk);
+ if (rc) {
+ dev_err(&pdev->dev, "Could not enable sclk\n");
+ goto out_error;
+ }
+
+ writeValue = ((clk_get_rate(iface->sclk) / 1000 / 1000 + 5) / 10) & 0x7F;
+ iowrite16(writeValue, &iface->regs_base->control);
+
+ /*
+ * We will not end up with a CLKDIV=0 because no one will specify
+ * 20kHz SCL or less in Kconfig now. (5 * 1000 / 20 = 250)
+ */
+ clkhilow = ((10 * 1000 / iface->twi_clk) + 1) / 2;
+
+ /* Set Twi interface clock as specified */
+ writeValue = (clkhilow << 8) | clkhilow;
+ iowrite16(writeValue, &iface->regs_base->clkdiv);
+
+ /* Enable TWI */
+ writeValue = ioread16(&iface->regs_base->control) | TWI_ENA;
+ iowrite16(writeValue, &iface->regs_base->control);
+
+ rc = i2c_add_numbered_adapter(p_adap);
+ if (rc < 0)
+ goto disable_clk;
+
+ platform_set_drvdata(pdev, iface);
+
+ dev_info(&pdev->dev, "ADI on-chip I2C TWI Controller, regs_base@%p\n",
+ iface->regs_base);
+
+ return 0;
+
+disable_clk:
+ clk_disable_unprepare(iface->sclk);
+
+out_error:
+ return rc;
+}
+
+static void i2c_adi_twi_remove(struct platform_device *pdev)
+{
+ struct adi_twi_iface *iface = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(iface->sclk);
+ i2c_del_adapter(&(iface->adap));
+}
+
+static struct platform_driver i2c_adi_twi_driver = {
+ .probe = i2c_adi_twi_probe,
+ .remove = i2c_adi_twi_remove,
+ .driver = {
+ .name = "i2c-adi-twi",
+ .pm = I2C_ADI_TWI_PM_OPS,
+ .of_match_table = of_match_ptr(adi_twi_of_match),
+ },
+};
+
+static int __init i2c_adi_twi_init(void)
+{
+ return platform_driver_register(&i2c_adi_twi_driver);
+}
+
+static void __exit i2c_adi_twi_exit(void)
+{
+ platform_driver_unregister(&i2c_adi_twi_driver);
+}
+
+subsys_initcall(i2c_adi_twi_init);
+module_exit(i2c_adi_twi_exit);
+
+MODULE_AUTHOR("Bryan Wu, Sonic Zhang");
+MODULE_DESCRIPTION("ADI on-chip I2C TWI Controller Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-adi-twi");
\ No newline at end of file
--
2.25.1
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