[PATCH v2 3/3] i2c: zx2967: add i2c controller driver for ZTE's zx2967 family
Shawn Guo
shawnguo at kernel.org
Wed Jan 25 01:38:55 PST 2017
On Mon, Jan 23, 2017 at 01:03:26PM +0800, Baoyou Xie wrote:
> This patch adds i2c controller driver for ZTE's zx2967 family.
>
> Signed-off-by: Baoyou Xie <baoyou.xie at linaro.org>
> ---
> drivers/i2c/busses/Kconfig | 9 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-zx2967.c | 690 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 700 insertions(+)
> create mode 100644 drivers/i2c/busses/i2c-zx2967.c
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index e4a603e..9609f45 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -1246,4 +1246,13 @@ config I2C_OPAL
> This driver can also be built as a module. If so, the module will be
> called as i2c-opal.
>
> +config I2C_ZX2967
> + tristate "ZTE zx2967 I2C support"
> + depends on ARCH_ZX
> + default y
> + help
> + Selecting this option will add ZX2967 I2C driver.
> + This driver can also be built as a module. If so, the module will be
> + called zx2967_i2c.
Called zx2967_i2c? Is it the .ko filename or the name we see in lsmod
command output? From what I have seen, neither of the names is
zx2967_i2c.
Also, I see the following failure in module installation.
$ insmod i2c-zx2967.ko
i2c_zx2967: Unknown symbol __clk_get_enable_count (err 0)
Error: could not insert module i2c-zx2967.ko: Unknown symbol in module
> +
> endmenu
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index beb4809..16b2901 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -101,6 +101,7 @@ obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
> obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
> obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o
> obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o
> +obj-$(CONFIG_I2C_ZX2967) += i2c-zx2967.o
>
> # External I2C/SMBus adapter drivers
> obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o
> diff --git a/drivers/i2c/busses/i2c-zx2967.c b/drivers/i2c/busses/i2c-zx2967.c
> new file mode 100644
> index 0000000..d38b7b7
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-zx2967.c
> @@ -0,0 +1,690 @@
> +/*
> + * ZTE's zx2967 family i2c bus controller driver
> + *
> + * Copyright (C) 2017 ZTE Ltd.
> + *
> + * Author: Baoyou Xie <baoyou.xie at linaro.org>
> + *
> + * License terms: GNU General Public License (GPL) version 2
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
clk-provider.h is only meant to be included by clock driver, not client
device drivers.
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/platform_device.h>
> +
> +#define REG_CMD 0x04
> +#define REG_DEVADDR_H 0x0C
> +#define REG_DEVADDR_L 0x10
> +#define REG_CLK_DIV_FS 0x14
> +#define REG_CLK_DIV_HS 0x18
> +#define REG_WRCONF 0x1C
> +#define REG_RDCONF 0x20
> +#define REG_DATA 0x24
> +#define REG_STAT 0x28
> +
> +#define I2C_STOP 0
> +#define I2C_MASTER BIT(0)
> +#define I2C_ADDR_MODE_TEN BIT(1)
> +#define I2C_IRQ_MSK_ENABLE BIT(3)
> +#define I2C_RW_READ BIT(4)
> +#define I2C_CMB_RW_EN BIT(5)
> +#define I2C_START BIT(6)
> +#define I2C_ADDR_MODE_TEN BIT(1)
> +
> +#define I2C_WFIFO_RESET BIT(7)
> +#define I2C_RFIFO_RESET BIT(7)
> +
> +#define I2C_IRQ_ACK_CLEAR BIT(7)
> +#define I2C_INT_MASK GENMASK(6, 0)
> +
> +#define I2C_TRANS_DONE BIT(0)
> +#define I2C_ERROR_DEVICE BIT(1)
> +#define I2C_ERROR_DATA BIT(2)
> +#define I2C_ERROR_MASK GENMASK(2, 1)
> +
> +#define I2C_SR_BUSY BIT(6)
> +
> +#define I2C_SR_EDEVICE BIT(1)
> +#define I2C_SR_EDATA BIT(2)
> +
> +#define I2C_FIFO_MAX 16
> +
> +#define I2C_TIMEOUT msecs_to_jiffies(1000)
> +
> +struct zx2967_i2c_info {
> + spinlock_t lock;
> + struct device *dev;
> + struct i2c_adapter adap;
> + struct clk *clk;
> + struct completion complete;
> + u32 clk_freq;
> + struct pinctrl *pin_ctrl;
> + void __iomem *reg_base;
> + size_t residue;
> + int id;
I don't see how this field is being used.
> + int irq;
> + int msg_rd;
> + u8 *buf;
> + u8 access_cnt;
> + bool is_suspended;
> +};
> +
> +static void zx2967_i2c_writel(struct zx2967_i2c_info *zx_i2c,
> + u32 val, unsigned long reg)
> +{
> + writel_relaxed(val, zx_i2c->reg_base + reg);
> +}
> +
> +static u32 zx2967_i2c_readl(struct zx2967_i2c_info *zx_i2c, unsigned long reg)
> +{
> + return readl_relaxed(zx_i2c->reg_base + reg);
> +}
> +
> +static void zx2967_i2c_writesb(struct zx2967_i2c_info *zx_i2c,
> + void *data, unsigned long reg, int len)
> +{
> + writesb(zx_i2c->reg_base + reg, data, len);
> +}
> +
> +static void zx2967_i2c_readsb(struct zx2967_i2c_info *zx_i2c,
> + void *data, unsigned long reg, int len)
> +{
> + readsb(zx_i2c->reg_base + reg, data, len);
> +}
> +
> +static void zx2967_i2c_start_ctrl(struct zx2967_i2c_info *zx_i2c)
> +{
> + u32 status;
> + u32 ctl;
> +
> + status = zx2967_i2c_readl(zx_i2c, REG_STAT);
> + status |= I2C_IRQ_ACK_CLEAR;
> + zx2967_i2c_writel(zx_i2c, status, REG_STAT);
> +
> + ctl = zx2967_i2c_readl(zx_i2c, REG_CMD);
> + if (zx_i2c->msg_rd)
> + ctl |= I2C_RW_READ;
> + else
> + ctl &= ~I2C_RW_READ;
> + ctl &= ~I2C_CMB_RW_EN;
> + ctl |= I2C_START;
> + zx2967_i2c_writel(zx_i2c, ctl, REG_CMD);
> +}
> +
> +static int zx2967_i2c_flush_fifos(struct zx2967_i2c_info *zx_i2c)
> +{
> + u32 val;
> + u32 offset;
> +
> + if (zx_i2c->msg_rd) {
> + offset = REG_RDCONF;
> + val = I2C_RFIFO_RESET;
> + } else {
> + offset = REG_WRCONF;
> + val = I2C_WFIFO_RESET;
> + }
> +
> + val |= zx2967_i2c_readl(zx_i2c, offset);
> + zx2967_i2c_writel(zx_i2c, val, offset);
> +
> + return 0;
> +}
> +
> +static int zx2967_i2c_empty_rx_fifo(struct zx2967_i2c_info *zx_i2c, u32 size)
> +{
> + u8 val[I2C_FIFO_MAX] = {0};
We need only one space between 'u8' and 'val'.
> + int i;
> +
> + if (size > I2C_FIFO_MAX) {
> + dev_err(zx_i2c->dev, "fifo size %d over the max value %d\n",
> + size, I2C_FIFO_MAX);
> + return -EINVAL;
> + }
> +
> + zx2967_i2c_readsb(zx_i2c, val, REG_DATA, size);
> + for (i = 0; i < size; i++) {
> + *(zx_i2c->buf++) = val[i];
> + zx_i2c->residue--;
> + if (zx_i2c->residue <= 0)
> + break;
> + }
> +
> + barrier();
> +
> + return 0;
> +}
> +
> +static int zx2967_i2c_fill_tx_fifo(struct zx2967_i2c_info *zx_i2c)
> +{
> + u8 *buf = zx_i2c->buf;
> + size_t residue = zx_i2c->residue;
> +
> + if (residue == 0) {
> + dev_err(zx_i2c->dev, "residue is %d\n", (int)residue);
> + return -EINVAL;
> + }
> +
> + if (residue <= I2C_FIFO_MAX) {
> + zx2967_i2c_writesb(zx_i2c, buf, REG_DATA, residue);
> +
> + /* Again update before writing to FIFO to make sure isr sees. */
> + zx_i2c->residue = 0;
> + zx_i2c->buf = NULL;
> + } else {
> + zx2967_i2c_writesb(zx_i2c, buf, REG_DATA, I2C_FIFO_MAX);
> + zx_i2c->residue -= I2C_FIFO_MAX;
> + zx_i2c->buf += I2C_FIFO_MAX;
> + }
> +
> + barrier();
> +
> + return 0;
> +}
> +
> +static int zx2967_i2c_reset_hardware(struct zx2967_i2c_info *zx_i2c)
> +{
> + u32 val;
> + u32 clk_div;
> + u32 status;
> +
> + val = I2C_MASTER | I2C_IRQ_MSK_ENABLE;
> + zx2967_i2c_writel(zx_i2c, val, REG_CMD);
> +
> + clk_div = clk_get_rate(zx_i2c->clk) / zx_i2c->clk_freq - 1;
> + zx2967_i2c_writel(zx_i2c, clk_div, REG_CLK_DIV_FS);
> + zx2967_i2c_writel(zx_i2c, clk_div, REG_CLK_DIV_HS);
> +
> + zx2967_i2c_writel(zx_i2c, I2C_FIFO_MAX - 1, REG_WRCONF);
> + zx2967_i2c_writel(zx_i2c, I2C_FIFO_MAX - 1, REG_RDCONF);
> + zx2967_i2c_writel(zx_i2c, 1, REG_RDCONF);
> +
> + if (zx2967_i2c_flush_fifos(zx_i2c))
zx2967_i2c_flush_fifos() seems to always return 0.
> + return -ETIMEDOUT;
> +
> + status = zx2967_i2c_readl(zx_i2c, REG_STAT);
> + if (status & (I2C_SR_BUSY))
The parentheses is not necessary.
> + return -EBUSY;
> + if (status & (I2C_SR_EDEVICE | I2C_SR_EDATA))
> + return -EIO;
> +
> + enable_irq(zx_i2c->irq);
> +
> + return 0;
> +}
> +
> +static void zx2967_i2c_isr_clr(struct zx2967_i2c_info *zx_i2c)
> +{
> + u32 status;
> +
> + status = zx2967_i2c_readl(zx_i2c, REG_STAT);
> + status |= I2C_IRQ_ACK_CLEAR;
> + zx2967_i2c_writel(zx_i2c, status, REG_STAT);
> +}
> +
> +static irqreturn_t zx2967_i2c_isr(int irq, void *dev_id)
> +{
> + u32 status;
> + struct zx2967_i2c_info *zx_i2c = (struct zx2967_i2c_info *)dev_id;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&zx_i2c->lock, flags);
> +
> + status = zx2967_i2c_readl(zx_i2c, REG_STAT) & I2C_INT_MASK;
> + zx2967_i2c_isr_clr(zx_i2c);
> +
> + if (status & I2C_ERROR_MASK) {
> + spin_unlock_irqrestore(&zx_i2c->lock, flags);
> + return IRQ_HANDLED;
> + }
> +
> + if (status & I2C_TRANS_DONE)
> + complete(&zx_i2c->complete);
> +
> + spin_unlock_irqrestore(&zx_i2c->lock, flags);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void zx2967_enable_tenbit(struct zx2967_i2c_info *zx_i2c, __u16 addr)
> +{
> + u16 val = (addr >> 7) & 0x7;
> +
> + if (val > 0) {
> + zx2967_i2c_writel(zx_i2c, val, REG_DEVADDR_H);
> + val = (zx2967_i2c_readl(zx_i2c, REG_CMD)) | I2C_ADDR_MODE_TEN;
> + zx2967_i2c_writel(zx_i2c, val, REG_CMD);
> + }
> +}
> +
> +static int
> +zx2967_i2c_xfer_read_bytes(struct zx2967_i2c_info *zx_i2c, u32 bytes)
> +{
> + unsigned long time_left;
> +
> + reinit_completion(&zx_i2c->complete);
> + zx2967_i2c_writel(zx_i2c, bytes - 1, REG_RDCONF);
> + zx2967_i2c_start_ctrl(zx_i2c);
> +
> + time_left = wait_for_completion_timeout(&zx_i2c->complete,
> + I2C_TIMEOUT);
> + if (time_left == 0) {
> + dev_err(zx_i2c->dev, "read i2c transfer timed out\n");
> + disable_irq(zx_i2c->irq);
> + zx2967_i2c_reset_hardware(zx_i2c);
> + return -EIO;
> + }
> +
> + zx2967_i2c_empty_rx_fifo(zx_i2c, bytes);
The function could return error.
> + return 0;
> +}
> +
> +static int zx2967_i2c_xfer_read(struct zx2967_i2c_info *zx_i2c)
> +{
> + int ret;
> + int i;
> +
> + for (i = 0; i < zx_i2c->access_cnt; i++) {
> + ret = zx2967_i2c_xfer_read_bytes(zx_i2c, I2C_FIFO_MAX);
> + if (ret)
> + return ret;
> + }
> +
> + if (zx_i2c->residue > 0) {
> + ret = zx2967_i2c_xfer_read_bytes(zx_i2c, I2C_FIFO_MAX);
> + if (ret)
> + return ret;
> + }
> +
> + zx_i2c->residue = 0;
> + zx_i2c->access_cnt = 0;
> + return 0;
> +}
> +
> +static int
> +zx2967_i2c_xfer_write_bytes(struct zx2967_i2c_info *zx_i2c, u32 bytes)
> +{
> + unsigned long time_left;
> +
> + reinit_completion(&zx_i2c->complete);
> + zx2967_i2c_fill_tx_fifo(zx_i2c);
It could return error.
> + zx2967_i2c_start_ctrl(zx_i2c);
> +
> + time_left = wait_for_completion_timeout(&zx_i2c->complete,
> + I2C_TIMEOUT);
> + if (time_left == 0) {
> + dev_err(zx_i2c->dev, "write i2c transfer timed out\n");
> + disable_irq(zx_i2c->irq);
> + zx2967_i2c_reset_hardware(zx_i2c);
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static int zx2967_i2c_xfer_write(struct zx2967_i2c_info *zx_i2c)
> +{
> + int ret;
> + int i;
> +
> + for (i = 0; i < zx_i2c->access_cnt; i++) {
> + ret = zx2967_i2c_xfer_write_bytes(zx_i2c, I2C_FIFO_MAX);
> + if (ret)
> + return ret;
> + }
> +
> + if (zx_i2c->residue > 0) {
> + ret = zx2967_i2c_xfer_write_bytes(zx_i2c, I2C_FIFO_MAX);
> + if (ret)
> + return ret;
> + }
> +
> + zx_i2c->residue = 0;
> + zx_i2c->access_cnt = 0;
> + return 0;
> +}
> +
> +static int zx2967_i2c_xfer_msg(struct zx2967_i2c_info *zx_i2c,
> + struct i2c_msg *msg)
> +{
> + if (msg->len == 0)
> + return -EINVAL;
> +
> + zx2967_i2c_flush_fifos(zx_i2c);
> +
> + zx_i2c->buf = msg->buf;
> + zx_i2c->residue = msg->len;
> + zx_i2c->access_cnt = msg->len / I2C_FIFO_MAX;
> + zx_i2c->msg_rd = (msg->flags & I2C_M_RD);
> +
> + if (zx_i2c->msg_rd)
> + return zx2967_i2c_xfer_read(zx_i2c);
> +
> + return zx2967_i2c_xfer_write(zx_i2c);
> +}
> +
> +static int zx2967_i2c_xfer(struct i2c_adapter *adap,
> + struct i2c_msg *msgs, int num)
> +{
> + struct zx2967_i2c_info *zx_i2c = i2c_get_adapdata(adap);
> + int ret;
> + int i;
> +
> + if (zx_i2c->is_suspended)
> + return -EBUSY;
> +
> + zx2967_i2c_writel(zx_i2c, (msgs->addr & 0x7f), REG_DEVADDR_L);
> + zx2967_i2c_writel(zx_i2c, (msgs->addr >> 7) & 0x7, REG_DEVADDR_H);
> + if (zx2967_i2c_readl(zx_i2c, REG_DEVADDR_H) > 0)
> + zx2967_enable_tenbit(zx_i2c, msgs->addr);
> +
> + for (i = 0; i < num; i++) {
> + ret = zx2967_i2c_xfer_msg(zx_i2c, &msgs[i]);
> + if (num > 1)
> + usleep_range(1000, 2000);
> + if (ret)
> + return ret;
The 'ret' check should probably be put before usleep_range check?
> + }
> +
> + return num;
> +}
> +
> +static void
> +zx2967_smbus_xfer_prepare(struct zx2967_i2c_info *zx_i2c, u16 addr,
> + char read_write, u8 command, int size,
> + union i2c_smbus_data *data)
> +{
> + u32 val;
> +
> + val = zx2967_i2c_readl(zx_i2c, REG_RDCONF);
> + val |= I2C_RFIFO_RESET;
> + zx2967_i2c_writel(zx_i2c, val, REG_RDCONF);
> + zx2967_i2c_writel(zx_i2c, (addr & 0x7f), REG_DEVADDR_L);
> +
> + zx2967_enable_tenbit(zx_i2c, addr);
> + val = zx2967_i2c_readl(zx_i2c, REG_CMD);
> + val &= ~I2C_RW_READ;
> + zx2967_i2c_writel(zx_i2c, val, REG_CMD);
> +
> + switch (size) {
> + case I2C_SMBUS_BYTE:
> + zx2967_i2c_writel(zx_i2c, command, REG_DATA);
> + break;
> + case I2C_SMBUS_BYTE_DATA:
> + zx2967_i2c_writel(zx_i2c, command, REG_DATA);
> + if (read_write == I2C_SMBUS_WRITE)
> + zx2967_i2c_writel(zx_i2c, data->byte, REG_DATA);
> + break;
> + case I2C_SMBUS_WORD_DATA:
> + zx2967_i2c_writel(zx_i2c, command, REG_DATA);
> + if (read_write == I2C_SMBUS_WRITE) {
> + zx2967_i2c_writel(zx_i2c, (data->word >> 8), REG_DATA);
> + zx2967_i2c_writel(zx_i2c, (data->word & 0xff),
> + REG_DATA);
> + }
> + break;
> + }
> +}
> +
> +static int zx2967_smbus_xfer_read(struct zx2967_i2c_info *zx_i2c, int size,
> + union i2c_smbus_data *data)
> +{
> + unsigned long time_left;
> + u8 buf[2];
> + u32 val;
> +
> + reinit_completion(&zx_i2c->complete);
> +
> + val = zx2967_i2c_readl(zx_i2c, REG_CMD);
> + val |= I2C_CMB_RW_EN;
> + zx2967_i2c_writel(zx_i2c, val, REG_CMD);
> +
> + val = zx2967_i2c_readl(zx_i2c, REG_CMD);
> + val |= I2C_START;
> + zx2967_i2c_writel(zx_i2c, val, REG_CMD);
> +
> + time_left = wait_for_completion_timeout(&zx_i2c->complete,
> + I2C_TIMEOUT);
> + if (time_left == 0) {
> + dev_err(zx_i2c->dev, "i2c read transfer timed out\n");
> + disable_irq(zx_i2c->irq);
> + zx2967_i2c_reset_hardware(zx_i2c);
> + return -EIO;
> + }
> +
> + usleep_range(1000, 2000);
> + switch (size) {
> + case I2C_SMBUS_BYTE:
> + case I2C_SMBUS_BYTE_DATA:
> + val = zx2967_i2c_readl(zx_i2c, REG_DATA);
> + data->byte = val;
> + break;
> + case I2C_SMBUS_WORD_DATA:
> + case I2C_SMBUS_PROC_CALL:
> + buf[0] = zx2967_i2c_readl(zx_i2c, REG_DATA);
> + buf[1] = zx2967_i2c_readl(zx_i2c, REG_DATA);
> + data->word = (buf[0] << 8) | buf[1];
> + break;
> + default:
> + dev_warn(zx_i2c->dev, "Unsupported transaction %d\n", size);
> + return -EOPNOTSUPP;
> + }
> +
> + return 0;
> +}
> +
> +static int zx2967_smbus_xfer_write(struct zx2967_i2c_info *zx_i2c)
> +{
> + unsigned long time_left;
> + u32 val;
> +
> + reinit_completion(&zx_i2c->complete);
> + val = zx2967_i2c_readl(zx_i2c, REG_CMD);
> + val |= I2C_START;
> + zx2967_i2c_writel(zx_i2c, val, REG_CMD);
> +
> + time_left = wait_for_completion_timeout(&zx_i2c->complete,
> + I2C_TIMEOUT);
> + if (time_left == 0) {
> + dev_err(zx_i2c->dev, "i2c write transfer timed out\n");
> + disable_irq(zx_i2c->irq);
> + zx2967_i2c_reset_hardware(zx_i2c);
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static int zx2967_smbus_xfer(struct i2c_adapter *adap, u16 addr,
> + unsigned short flags, char read_write,
> + u8 command, int size, union i2c_smbus_data *data)
> +{
> + struct zx2967_i2c_info *zx_i2c = i2c_get_adapdata(adap);
> +
> + if (size == I2C_SMBUS_QUICK)
> + read_write = I2C_SMBUS_WRITE;
> +
> + switch (size) {
> + case I2C_SMBUS_QUICK:
> + case I2C_SMBUS_BYTE:
> + case I2C_SMBUS_BYTE_DATA:
> + case I2C_SMBUS_WORD_DATA:
> + zx2967_smbus_xfer_prepare(zx_i2c, addr, read_write,
> + command, size, data);
> + break;
> + default:
> + dev_warn(&adap->dev, "Unsupported transaction %d\n", size);
> + return -EOPNOTSUPP;
> + }
> +
> + if (read_write == I2C_SMBUS_READ)
> + return zx2967_smbus_xfer_read(zx_i2c, size, data);
> +
> + return zx2967_smbus_xfer_write(zx_i2c);
> +}
> +
> +#define ZX2967_I2C_FUNCS (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)
Have a newline here.
> +static u32 zx2967_i2c_func(struct i2c_adapter *adap)
> +{
> + return ZX2967_I2C_FUNCS;
> +}
> +
> +static int __maybe_unused zx2967_i2c_suspend(struct device *dev)
> +{
> + struct zx2967_i2c_info *zx_i2c = dev_get_drvdata(dev);
> +
> + zx_i2c->is_suspended = true;
> + if (__clk_get_enable_count(zx_i2c->clk) == 1)
> + clk_disable_unprepare(zx_i2c->clk);
clk_prepare_enable() and clk_disable_unprepare() should always be called
in a balanced way. In that case, you shouldn't need to check enable
count.
> +
> + return 0;
> +}
> +
> +static int __maybe_unused zx2967_i2c_resume(struct device *dev)
> +{
> + struct zx2967_i2c_info *zx_i2c = dev_get_drvdata(dev);
> +
> + zx_i2c->is_suspended = false;
> + clk_prepare_enable(zx_i2c->clk);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static const struct dev_pm_ops zx2967_i2c_dev_pm_ops = {
> + .suspend = zx2967_i2c_suspend,
> + .resume = zx2967_i2c_resume,
> +};
> +#define ZX2967_I2C_DEV_PM_OPS (&zx2967_i2c_dev_pm_ops)
> +#else
> +#define ZX2967_I2C_DEV_PM_OPS NULL
> +#endif
> +
> +static const struct i2c_algorithm zx2967_i2c_algo = {
> + .master_xfer = zx2967_i2c_xfer,
> + .smbus_xfer = zx2967_smbus_xfer,
> + .functionality = zx2967_i2c_func,
> +};
> +
> +static const struct of_device_id zx2967_i2c_of_match[] = {
> + { .compatible = "zte,zx296718-i2c", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, zx2967_i2c_of_match);
> +
> +static int zx2967_i2c_probe(struct platform_device *pdev)
> +{
> + struct zx2967_i2c_info *zx_i2c;
> + void __iomem *reg_base;
> + struct resource *res;
> + struct clk *clk;
> + int ret;
> +
> + zx_i2c = devm_kzalloc(&pdev->dev, sizeof(*zx_i2c), GFP_KERNEL);
> + if (!zx_i2c)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + reg_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(reg_base))
> + return PTR_ERR(reg_base);
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err(&pdev->dev, "missing controller clock");
> + return PTR_ERR(clk);
> + }
> +
> + ret = clk_prepare_enable(clk);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to enable i2c_clk\n");
> + return ret;
> + }
> +
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + return ret;
> + zx_i2c->irq = ret;
> +
> + device_property_read_u32(&pdev->dev, "clock-frequency",
> + &zx_i2c->clk_freq);
Since you list it in bindings doc as a required property, shouldn't you
check the return of the call to make sure the property is found
successfully?
> + zx_i2c->reg_base = reg_base;
> + zx_i2c->clk = clk;
> + zx_i2c->id = pdev->id;
> + zx_i2c->dev = &pdev->dev;
> +
> + zx_i2c->pin_ctrl = devm_pinctrl_get_select(&pdev->dev, "pinctrl-0");
> + if (IS_ERR(zx_i2c->pin_ctrl))
> + dev_info(&pdev->dev, "pinctrl-0 pin is not specified in dts\n");
It seems that I did not make my comment clear on the previous version.
I was trying to say you do not need to explicitly call pinctrl function,
if what you need is just to request 'default' pin state. Take a look at
commit ab78029ecc34 ("drivers/pinctrl: grab default handles from device
core"), and you will know what I'm saying.
Shawn
> +
> + spin_lock_init(&zx_i2c->lock);
> + init_completion(&zx_i2c->complete);
> + platform_set_drvdata(pdev, zx_i2c);
> +
> + ret = zx2967_i2c_reset_hardware(zx_i2c);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to initialize i2c controller\n");
> + goto err_clk_unprepare;
> + }
> +
> + ret = devm_request_irq(&pdev->dev, zx_i2c->irq,
> + zx2967_i2c_isr, 0, dev_name(&pdev->dev), zx_i2c);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to request irq %i\n", zx_i2c->irq);
> + goto err_clk_unprepare;
> + }
> +
> + i2c_set_adapdata(&zx_i2c->adap, zx_i2c);
> + zx_i2c->adap.owner = THIS_MODULE;
> + zx_i2c->adap.class = I2C_CLASS_DEPRECATED;
> + strlcpy(zx_i2c->adap.name, "zx2967 i2c adapter",
> + sizeof(zx_i2c->adap.name));
> + zx_i2c->adap.algo = &zx2967_i2c_algo;
> + zx_i2c->adap.dev.parent = &pdev->dev;
> + zx_i2c->adap.nr = pdev->id;
> + zx_i2c->adap.dev.of_node = pdev->dev.of_node;
> +
> + ret = i2c_add_numbered_adapter(&zx_i2c->adap);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to add zx2967 i2c adapter\n");
> + goto err_clk_unprepare;
> + }
> +
> + return 0;
> +
> +err_clk_unprepare:
> + clk_disable_unprepare(zx_i2c->clk);
> + return ret;
> +}
> +
> +static int zx2967_i2c_remove(struct platform_device *pdev)
> +{
> + struct zx2967_i2c_info *zx_i2c = platform_get_drvdata(pdev);
> +
> + i2c_del_adapter(&zx_i2c->adap);
> + clk_disable_unprepare(zx_i2c->clk);
> +
> + return 0;
> +}
> +
> +static struct platform_driver zx2967_i2c_driver = {
> + .probe = zx2967_i2c_probe,
> + .remove = zx2967_i2c_remove,
> + .driver = {
> + .name = "zx2967_i2c",
> + .of_match_table = zx2967_i2c_of_match,
> + .pm = ZX2967_I2C_DEV_PM_OPS,
> + },
> +};
> +module_platform_driver(zx2967_i2c_driver);
> +
> +MODULE_AUTHOR("Baoyou Xie <baoyou.xie at linaro.org>");
> +MODULE_DESCRIPTION("ZTE zx2967 I2C Bus Controller driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>
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