+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2017 Sanechips Technology Co., Ltd.
- * Copyright 2017 Linaro Ltd.
- *
- * Author: Baoyou Xie <baoyou.xie@linaro.org>
- */
-
-#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;
- int error;
-};
-
-static void zx2967_i2c_writel(struct zx2967_i2c *i2c,
- u32 val, unsigned long reg)
-{
- writel_relaxed(val, i2c->reg_base + reg);
-}
-
-static u32 zx2967_i2c_readl(struct zx2967_i2c *i2c, unsigned long reg)
-{
- return readl_relaxed(i2c->reg_base + reg);
-}
-
-static void zx2967_i2c_writesb(struct zx2967_i2c *i2c,
- void *data, unsigned long reg, int len)
-{
- writesb(i2c->reg_base + reg, data, len);
-}
-
-static void zx2967_i2c_readsb(struct zx2967_i2c *i2c,
- void *data, unsigned long reg, int len)
-{
- readsb(i2c->reg_base + reg, data, len);
-}
-
-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);
-}
-
-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);
-}
-
-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;
-}
-
-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;
-}
-
-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;
-}
-
-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);
-}
-
-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;
-}
-
-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);
-}
-
-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;
-}
-
-static int zx2967_i2c_xfer_msg(struct zx2967_i2c *i2c,
- struct i2c_msg *msg)
-{
- int ret;
- int i;
-
- 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;
-}
-
-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;
-
- 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;
-}
-
-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;
- }
-}
-
-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;
-}
-
-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;
-}
-
-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);
-}
-
-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;
-}
-
-static int __maybe_unused zx2967_i2c_suspend(struct device *dev)
-{
- struct zx2967_i2c *i2c = dev_get_drvdata(dev);
-
- i2c_mark_adapter_suspended(&i2c->adap);
- clk_disable_unprepare(i2c->clk);
-
- return 0;
-}
-
-static int __maybe_unused zx2967_i2c_resume(struct device *dev)
-{
- struct zx2967_i2c *i2c = dev_get_drvdata(dev);
-
- clk_prepare_enable(i2c->clk);
- i2c_mark_adapter_resumed(&i2c->adap);
-
- return 0;
-}
-
-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 i2c_adapter_quirks zx2967_i2c_quirks = {
- .flags = I2C_AQ_NO_ZERO_LEN,
-};
-
-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 clk *clk;
- int ret;
-
- i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
- if (!i2c)
- return -ENOMEM;
-
- reg_base = devm_platform_ioremap_resource(pdev, 0);
- 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.quirks = &zx2967_i2c_quirks;
- 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;
-}
-
-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;
-}
-
-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");
projects / platform / kernel / linux-rpi.git / commitdiff