Release 4.16 drivers/i2c/busses/i2c-zx2967.c

Directory: drivers/i2c/busses
/*
 * Copyright (C) 2017 Sanechips Technology Co., Ltd.
 * Copyright 2017 Linaro Ltd.
 *
 * Author: Baoyou Xie <baoyou.xie@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.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_LOW_MASK		GENMASK(6, 0)

#define I2C_ADDR_LOW_SHIFT		0

#define I2C_ADDR_HI_MASK		GENMASK(2, 0)

#define I2C_ADDR_HI_SHIFT		7


#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_SR_EDEVICE			BIT(1)

#define I2C_SR_EDATA			BIT(2)


#define I2C_FIFO_MAX			16


#define I2C_TIMEOUT			msecs_to_jiffies(1000)


#define DEV(i2c)			((i2c)->adap.dev.parent)


struct zx2967_i2c {
	
struct i2c_adapter	adap;
	
struct clk		*clk;
	
struct completion	complete;
	
u32			clk_freq;
	
void __iomem		*reg_base;
	
size_t			residue;
	
int			irq;
	
int			msg_rd;
	
u8			*cur_trans;
	
u8			access_cnt;
	
bool			is_suspended;
	
int			error;
};



static void zx2967_i2c_writel(struct zx2967_i2c *i2c,
			      u32 val, unsigned long reg)
{
	writel_relaxed(val, i2c->reg_base + reg);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 29 100.00% 1 100.00%
Total 29 100.00% 1 100.00%



static u32 zx2967_i2c_readl(struct zx2967_i2c *i2c, unsigned long reg)
{
	return readl_relaxed(i2c->reg_base + reg);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 25 100.00% 1 100.00%
Total 25 100.00% 1 100.00%



static void zx2967_i2c_writesb(struct zx2967_i2c *i2c,
			       void *data, unsigned long reg, int len)
{
	writesb(i2c->reg_base + reg, data, len);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 35 100.00% 1 100.00%
Total 35 100.00% 1 100.00%



static void zx2967_i2c_readsb(struct zx2967_i2c *i2c,
			      void *data, unsigned long reg, int len)
{
	readsb(i2c->reg_base + reg, data, len);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 35 100.00% 1 100.00%
Total 35 100.00% 1 100.00%



static void zx2967_i2c_start_ctrl(struct zx2967_i2c *i2c)
{
	u32 status;
	u32 ctl;

	status = zx2967_i2c_readl(i2c, REG_STAT);
	status |= I2C_IRQ_ACK_CLEAR;
	zx2967_i2c_writel(i2c, status, REG_STAT);

	ctl = zx2967_i2c_readl(i2c, REG_CMD);
	if (i2c->msg_rd)
		ctl |= I2C_RW_READ;
	else
		ctl &= ~I2C_RW_READ;
	ctl &= ~I2C_CMB_RW_EN;
	ctl |= I2C_START;
	zx2967_i2c_writel(i2c, ctl, REG_CMD);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 82 100.00% 1 100.00%
Total 82 100.00% 1 100.00%



static void zx2967_i2c_flush_fifos(struct zx2967_i2c *i2c)
{
	u32 offset;
	u32 val;

	if (i2c->msg_rd) {
		offset = REG_RDCONF;
		val = I2C_RFIFO_RESET;
	} else {
		offset = REG_WRCONF;
		val = I2C_WFIFO_RESET;
	}

	val |= zx2967_i2c_readl(i2c, offset);
	zx2967_i2c_writel(i2c, val, offset);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 62 100.00% 1 100.00%
Total 62 100.00% 1 100.00%



static int zx2967_i2c_empty_rx_fifo(struct zx2967_i2c *i2c, u32 size)
{
	u8 val[I2C_FIFO_MAX] = {0};
	int i;

	if (size > I2C_FIFO_MAX) {
		dev_err(DEV(i2c), "fifo size %d over the max value %d\n",
			size, I2C_FIFO_MAX);
		return -EINVAL;
	}

	zx2967_i2c_readsb(i2c, val, REG_DATA, size);
	for (i = 0; i < size; i++) {
		*i2c->cur_trans++ = val[i];
		i2c->residue--;
	}

	barrier();

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 101 100.00% 1 100.00%
Total 101 100.00% 1 100.00%



static int zx2967_i2c_fill_tx_fifo(struct zx2967_i2c *i2c)
{
	size_t residue = i2c->residue;
	u8 *buf = i2c->cur_trans;

	if (residue == 0) {
		dev_err(DEV(i2c), "residue is %d\n", (int)residue);
		return -EINVAL;
	}

	if (residue <= I2C_FIFO_MAX) {
		zx2967_i2c_writesb(i2c, buf, REG_DATA, residue);

		/* Again update before writing to FIFO to make sure isr sees. */
		i2c->residue = 0;
		i2c->cur_trans = NULL;
	} else {
		zx2967_i2c_writesb(i2c, buf, REG_DATA, I2C_FIFO_MAX);
		i2c->residue -= I2C_FIFO_MAX;
		i2c->cur_trans += I2C_FIFO_MAX;
	}

	barrier();

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 117 100.00% 1 100.00%
Total 117 100.00% 1 100.00%



static int zx2967_i2c_reset_hardware(struct zx2967_i2c *i2c)
{
	u32 val;
	u32 clk_div;

	val = I2C_MASTER | I2C_IRQ_MSK_ENABLE;
	zx2967_i2c_writel(i2c, val, REG_CMD);

	clk_div = clk_get_rate(i2c->clk) / i2c->clk_freq - 1;
	zx2967_i2c_writel(i2c, clk_div, REG_CLK_DIV_FS);
	zx2967_i2c_writel(i2c, clk_div, REG_CLK_DIV_HS);

	zx2967_i2c_writel(i2c, I2C_FIFO_MAX - 1, REG_WRCONF);
	zx2967_i2c_writel(i2c, I2C_FIFO_MAX - 1, REG_RDCONF);
	zx2967_i2c_writel(i2c, 1, REG_RDCONF);

	zx2967_i2c_flush_fifos(i2c);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 104 100.00% 1 100.00%
Total 104 100.00% 1 100.00%



static void zx2967_i2c_isr_clr(struct zx2967_i2c *i2c)
{
	u32 status;

	status = zx2967_i2c_readl(i2c, REG_STAT);
	status |= I2C_IRQ_ACK_CLEAR;
	zx2967_i2c_writel(i2c, status, REG_STAT);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%



static irqreturn_t zx2967_i2c_isr(int irq, void *dev_id)
{
	u32 status;
	struct zx2967_i2c *i2c = (struct zx2967_i2c *)dev_id;

	status = zx2967_i2c_readl(i2c, REG_STAT) & I2C_INT_MASK;
	zx2967_i2c_isr_clr(i2c);

	if (status & I2C_SR_EDEVICE)
		i2c->error = -ENXIO;
	else if (status & I2C_SR_EDATA)
		i2c->error = -EIO;
	else if (status & I2C_TRANS_DONE)
		i2c->error = 0;
	else
		goto done;

	complete(&i2c->complete);
done:
	return IRQ_HANDLED;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 101 100.00% 1 100.00%
Total 101 100.00% 1 100.00%



static void zx2967_set_addr(struct zx2967_i2c *i2c, u16 addr)
{
	u16 val;

	val = (addr >> I2C_ADDR_LOW_SHIFT) & I2C_ADDR_LOW_MASK;
	zx2967_i2c_writel(i2c, val, REG_DEVADDR_L);

	val = (addr >> I2C_ADDR_HI_SHIFT) & I2C_ADDR_HI_MASK;
	zx2967_i2c_writel(i2c, val, REG_DEVADDR_H);
	if (val)
		val = zx2967_i2c_readl(i2c, REG_CMD) | I2C_ADDR_MODE_TEN;
	else
		val = zx2967_i2c_readl(i2c, REG_CMD) & ~I2C_ADDR_MODE_TEN;
	zx2967_i2c_writel(i2c, val, REG_CMD);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 92 100.00% 1 100.00%
Total 92 100.00% 1 100.00%



static int zx2967_i2c_xfer_bytes(struct zx2967_i2c *i2c, u32 bytes)
{
	unsigned long time_left;
	int rd = i2c->msg_rd;
	int ret;

	reinit_completion(&i2c->complete);

	if (rd) {
		zx2967_i2c_writel(i2c, bytes - 1, REG_RDCONF);
	} else {
		ret = zx2967_i2c_fill_tx_fifo(i2c);
		if (ret)
			return ret;
	}

	zx2967_i2c_start_ctrl(i2c);

	time_left = wait_for_completion_timeout(&i2c->complete,
						I2C_TIMEOUT);
	if (time_left == 0)
		return -ETIMEDOUT;

	if (i2c->error)
		return i2c->error;

	return rd ? zx2967_i2c_empty_rx_fifo(i2c, bytes) : 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 120 100.00% 1 100.00%
Total 120 100.00% 1 100.00%



static int zx2967_i2c_xfer_msg(struct zx2967_i2c *i2c,
			       struct i2c_msg *msg)
{
	int ret;
	int i;

	if (msg->len == 0)
		return -EINVAL;

	zx2967_i2c_flush_fifos(i2c);

	i2c->cur_trans = msg->buf;
	i2c->residue = msg->len;
	i2c->access_cnt = msg->len / I2C_FIFO_MAX;
	i2c->msg_rd = msg->flags & I2C_M_RD;

	for (i = 0; i < i2c->access_cnt; i++) {
		ret = zx2967_i2c_xfer_bytes(i2c, I2C_FIFO_MAX);
		if (ret)
			return ret;
	}

	if (i2c->residue > 0) {
		ret = zx2967_i2c_xfer_bytes(i2c, i2c->residue);
		if (ret)
			return ret;
	}

	i2c->residue = 0;
	i2c->access_cnt = 0;

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 151 100.00% 1 100.00%
Total 151 100.00% 1 100.00%



static int zx2967_i2c_xfer(struct i2c_adapter *adap,
			   struct i2c_msg *msgs, int num)
{
	struct zx2967_i2c *i2c = i2c_get_adapdata(adap);
	int ret;
	int i;

	if (i2c->is_suspended)
		return -EBUSY;

	zx2967_set_addr(i2c, msgs->addr);

	for (i = 0; i < num; i++) {
		ret = zx2967_i2c_xfer_msg(i2c, &msgs[i]);
		if (ret)
			return ret;
	}

	return num;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 92 100.00% 1 100.00%
Total 92 100.00% 1 100.00%


static void

zx2967_smbus_xfer_prepare(struct zx2967_i2c *i2c, u16 addr,
			  char read_write, u8 command, int size,
			  union i2c_smbus_data *data)
{
	u32 val;

	val = zx2967_i2c_readl(i2c, REG_RDCONF);
	val |= I2C_RFIFO_RESET;
	zx2967_i2c_writel(i2c, val, REG_RDCONF);
	zx2967_set_addr(i2c, addr);
	val = zx2967_i2c_readl(i2c, REG_CMD);
	val &= ~I2C_RW_READ;
	zx2967_i2c_writel(i2c, val, REG_CMD);

	switch (size) {
	case I2C_SMBUS_BYTE:
		zx2967_i2c_writel(i2c, command, REG_DATA);
		break;
	case I2C_SMBUS_BYTE_DATA:
		zx2967_i2c_writel(i2c, command, REG_DATA);
		if (read_write == I2C_SMBUS_WRITE)
			zx2967_i2c_writel(i2c, data->byte, REG_DATA);
		break;
	case I2C_SMBUS_WORD_DATA:
		zx2967_i2c_writel(i2c, command, REG_DATA);
		if (read_write == I2C_SMBUS_WRITE) {
			zx2967_i2c_writel(i2c, (data->word >> 8), REG_DATA);
			zx2967_i2c_writel(i2c, (data->word & 0xff),
					  REG_DATA);
		}
		break;
	}
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 183 100.00% 1 100.00%
Total 183 100.00% 1 100.00%



static int zx2967_smbus_xfer_read(struct zx2967_i2c *i2c, int size,
				  union i2c_smbus_data *data)
{
	unsigned long time_left;
	u8 buf[2];
	u32 val;

	reinit_completion(&i2c->complete);

	val = zx2967_i2c_readl(i2c, REG_CMD);
	val |= I2C_CMB_RW_EN;
	zx2967_i2c_writel(i2c, val, REG_CMD);

	val = zx2967_i2c_readl(i2c, REG_CMD);
	val |= I2C_START;
	zx2967_i2c_writel(i2c, val, REG_CMD);

	time_left = wait_for_completion_timeout(&i2c->complete,
						I2C_TIMEOUT);
	if (time_left == 0)
		return -ETIMEDOUT;

	if (i2c->error)
		return i2c->error;

	switch (size) {
	case I2C_SMBUS_BYTE:
	case I2C_SMBUS_BYTE_DATA:
		val = zx2967_i2c_readl(i2c, REG_DATA);
		data->byte = val;
		break;
	case I2C_SMBUS_WORD_DATA:
	case I2C_SMBUS_PROC_CALL:
		buf[0] = zx2967_i2c_readl(i2c, REG_DATA);
		buf[1] = zx2967_i2c_readl(i2c, REG_DATA);
		data->word = (buf[0] << 8) | buf[1];
		break;
	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 202 100.00% 1 100.00%
Total 202 100.00% 1 100.00%



static int zx2967_smbus_xfer_write(struct zx2967_i2c *i2c)
{
	unsigned long time_left;
	u32 val;

	reinit_completion(&i2c->complete);
	val = zx2967_i2c_readl(i2c, REG_CMD);
	val |= I2C_START;
	zx2967_i2c_writel(i2c, val, REG_CMD);

	time_left = wait_for_completion_timeout(&i2c->complete,
						I2C_TIMEOUT);
	if (time_left == 0)
		return -ETIMEDOUT;

	if (i2c->error)
		return i2c->error;

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 84 100.00% 1 100.00%
Total 84 100.00% 1 100.00%



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 *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(i2c, addr, read_write,
					  command, size, data);
		break;
	default:
		return -EOPNOTSUPP;
	}

	if (read_write == I2C_SMBUS_READ)
		return zx2967_smbus_xfer_read(i2c, size, data);

	return zx2967_smbus_xfer_write(i2c);
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 113 100.00% 1 100.00%
Total 113 100.00% 1 100.00%



static u32 zx2967_i2c_func(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C |
	       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_SMBUS_I2C_BLOCK;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 28 100.00% 1 100.00%
Total 28 100.00% 1 100.00%



static int __maybe_unused zx2967_i2c_suspend(struct device *dev)
{
	struct zx2967_i2c *i2c = dev_get_drvdata(dev);

	i2c->is_suspended = true;
	clk_disable_unprepare(i2c->clk);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 38 100.00% 1 100.00%
Total 38 100.00% 1 100.00%



static int __maybe_unused zx2967_i2c_resume(struct device *dev)
{
	struct zx2967_i2c *i2c = dev_get_drvdata(dev);

	i2c->is_suspended = false;
	clk_prepare_enable(i2c->clk);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 38 100.00% 1 100.00%
Total 38 100.00% 1 100.00%

static SIMPLE_DEV_PM_OPS(zx2967_i2c_dev_pm_ops,
			 zx2967_i2c_suspend, zx2967_i2c_resume);


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 *i2c;
	void __iomem *reg_base;
	struct resource *res;
	struct clk *clk;
	int ret;

	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
	if (!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 = device_property_read_u32(&pdev->dev, "clock-frequency",
				       &i2c->clk_freq);
	if (ret) {
		dev_err(&pdev->dev, "missing clock-frequency");
		return ret;
	}

	ret = platform_get_irq(pdev, 0);
	if (ret < 0)
		return ret;

	i2c->irq = ret;
	i2c->reg_base = reg_base;
	i2c->clk = clk;

	init_completion(&i2c->complete);
	platform_set_drvdata(pdev, i2c);

	ret = zx2967_i2c_reset_hardware(i2c);
	if (ret) {
		dev_err(&pdev->dev, "failed to initialize i2c controller\n");
		goto err_clk_unprepare;
	}

	ret = devm_request_irq(&pdev->dev, i2c->irq,
			zx2967_i2c_isr, 0, dev_name(&pdev->dev), i2c);
	if (ret) {
		dev_err(&pdev->dev, "failed to request irq %i\n", i2c->irq);
		goto err_clk_unprepare;
	}

	i2c_set_adapdata(&i2c->adap, i2c);
	strlcpy(i2c->adap.name, "zx2967 i2c adapter",
		sizeof(i2c->adap.name));
	i2c->adap.algo = &zx2967_i2c_algo;
	i2c->adap.nr = pdev->id;
	i2c->adap.dev.parent = &pdev->dev;
	i2c->adap.dev.of_node = pdev->dev.of_node;

	ret = i2c_add_numbered_adapter(&i2c->adap);
	if (ret)
		goto err_clk_unprepare;

	return 0;

err_clk_unprepare:
	clk_disable_unprepare(i2c->clk);
	return ret;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 432 100.00% 1 100.00%
Total 432 100.00% 1 100.00%



static int zx2967_i2c_remove(struct platform_device *pdev)
{
	struct zx2967_i2c *i2c = platform_get_drvdata(pdev);

	i2c_del_adapter(&i2c->adap);
	clk_disable_unprepare(i2c->clk);

	return 0;
}

Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 39 100.00% 1 100.00%
Total 39 100.00% 1 100.00%


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@linaro.org>");
MODULE_DESCRIPTION("ZTE ZX2967 I2C Bus Controller driver");
MODULE_LICENSE("GPL v2");
Overall Contributors
Person Tokens Prop Commits CommitProp
Baoyou Xie 2644 99.96% 1 50.00%
Wolfram Sang 1 0.04% 1 50.00%
Total 2645 100.00% 2 100.00%
Directory: drivers/i2c/busses

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.
Person	Tokens	Prop	Commits	CommitProp
Baoyou Xie	29	100.00%	1	100.00%
Total	29	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.16 drivers/i2c/busses/i2c-zx2967.c

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Contributors

Overall Contributors
