u-boot/drivers/i2c/rk_i2c.c

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/*
* (C) Copyright 2015 Google, Inc
*
* (C) Copyright 2008-2014 Rockchip Electronics
* Peter, Software Engineering, <superpeter.cai@gmail.com>.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <i2c.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/i2c.h>
#include <asm/arch/periph.h>
#include <dm/pinctrl.h>
#include <linux/sizes.h>
DECLARE_GLOBAL_DATA_PTR;
/* i2c timerout */
#define I2C_TIMEOUT_MS 100
#define I2C_RETRY_COUNT 3
/* rk i2c fifo max transfer bytes */
#define RK_I2C_FIFO_SIZE 32
struct rk_i2c {
struct clk clk;
struct i2c_regs *regs;
unsigned int speed;
};
static inline void rk_i2c_get_div(int div, int *divh, int *divl)
{
*divl = div / 2;
if (div % 2 == 0)
*divh = div / 2;
else
*divh = DIV_ROUND_UP(div, 2);
}
/*
* SCL Divisor = 8 * (CLKDIVL+1 + CLKDIVH+1)
* SCL = PCLK / SCLK Divisor
* i2c_rate = PCLK
*/
static void rk_i2c_set_clk(struct rk_i2c *i2c, uint32_t scl_rate)
{
uint32_t i2c_rate;
int div, divl, divh;
/* First get i2c rate from pclk */
i2c_rate = clk_get_rate(&i2c->clk);
div = DIV_ROUND_UP(i2c_rate, scl_rate * 8) - 2;
divh = 0;
divl = 0;
if (div >= 0)
rk_i2c_get_div(div, &divh, &divl);
writel(I2C_CLKDIV_VAL(divl, divh), &i2c->regs->clkdiv);
debug("rk_i2c_set_clk: i2c rate = %d, scl rate = %d\n", i2c_rate,
scl_rate);
debug("set i2c clk div = %d, divh = %d, divl = %d\n", div, divh, divl);
debug("set clk(I2C_CLKDIV: 0x%08x)\n", readl(&i2c->regs->clkdiv));
}
static void rk_i2c_show_regs(struct i2c_regs *regs)
{
#ifdef DEBUG
uint i;
debug("i2c_con: 0x%08x\n", readl(&regs->con));
debug("i2c_clkdiv: 0x%08x\n", readl(&regs->clkdiv));
debug("i2c_mrxaddr: 0x%08x\n", readl(&regs->mrxaddr));
debug("i2c_mrxraddR: 0x%08x\n", readl(&regs->mrxraddr));
debug("i2c_mtxcnt: 0x%08x\n", readl(&regs->mtxcnt));
debug("i2c_mrxcnt: 0x%08x\n", readl(&regs->mrxcnt));
debug("i2c_ien: 0x%08x\n", readl(&regs->ien));
debug("i2c_ipd: 0x%08x\n", readl(&regs->ipd));
debug("i2c_fcnt: 0x%08x\n", readl(&regs->fcnt));
for (i = 0; i < 8; i++)
debug("i2c_txdata%d: 0x%08x\n", i, readl(&regs->txdata[i]));
for (i = 0; i < 8; i++)
debug("i2c_rxdata%d: 0x%08x\n", i, readl(&regs->rxdata[i]));
#endif
}
static int rk_i2c_send_start_bit(struct rk_i2c *i2c)
{
struct i2c_regs *regs = i2c->regs;
ulong start;
debug("I2c Send Start bit.\n");
writel(I2C_IPD_ALL_CLEAN, &regs->ipd);
writel(I2C_CON_EN | I2C_CON_START, &regs->con);
writel(I2C_STARTIEN, &regs->ien);
start = get_timer(0);
while (1) {
if (readl(&regs->ipd) & I2C_STARTIPD) {
writel(I2C_STARTIPD, &regs->ipd);
break;
}
if (get_timer(start) > I2C_TIMEOUT_MS) {
debug("I2C Send Start Bit Timeout\n");
rk_i2c_show_regs(regs);
return -ETIMEDOUT;
}
udelay(1);
}
return 0;
}
static int rk_i2c_send_stop_bit(struct rk_i2c *i2c)
{
struct i2c_regs *regs = i2c->regs;
ulong start;
debug("I2c Send Stop bit.\n");
writel(I2C_IPD_ALL_CLEAN, &regs->ipd);
writel(I2C_CON_EN | I2C_CON_STOP, &regs->con);
writel(I2C_CON_STOP, &regs->ien);
start = get_timer(0);
while (1) {
if (readl(&regs->ipd) & I2C_STOPIPD) {
writel(I2C_STOPIPD, &regs->ipd);
break;
}
if (get_timer(start) > I2C_TIMEOUT_MS) {
debug("I2C Send Start Bit Timeout\n");
rk_i2c_show_regs(regs);
return -ETIMEDOUT;
}
udelay(1);
}
return 0;
}
static inline void rk_i2c_disable(struct rk_i2c *i2c)
{
writel(0, &i2c->regs->con);
}
static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
uchar *buf, uint b_len)
{
struct i2c_regs *regs = i2c->regs;
uchar *pbuf = buf;
uint bytes_remain_len = b_len;
uint bytes_xferred = 0;
uint words_xferred = 0;
ulong start;
uint con = 0;
uint rxdata;
uint i, j;
int err;
bool snd_chunk = false;
debug("rk_i2c_read: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
chip, reg, r_len, b_len);
err = rk_i2c_send_start_bit(i2c);
if (err)
return err;
writel(I2C_MRXADDR_SET(1, chip << 1 | 1), &regs->mrxaddr);
if (r_len == 0) {
writel(0, &regs->mrxraddr);
} else if (r_len < 4) {
writel(I2C_MRXRADDR_SET(r_len, reg), &regs->mrxraddr);
} else {
debug("I2C Read: addr len %d not supported\n", r_len);
return -EIO;
}
while (bytes_remain_len) {
if (bytes_remain_len > RK_I2C_FIFO_SIZE) {
con = I2C_CON_EN;
bytes_xferred = 32;
} else {
/*
* The hw can read up to 32 bytes at a time. If we need
* more than one chunk, send an ACK after the last byte.
*/
con = I2C_CON_EN | I2C_CON_LASTACK;
bytes_xferred = bytes_remain_len;
}
words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
/*
* make sure we are in plain RX mode if we read a second chunk
*/
if (snd_chunk)
con |= I2C_CON_MOD(I2C_MODE_RX);
else
con |= I2C_CON_MOD(I2C_MODE_TRX);
writel(con, &regs->con);
writel(bytes_xferred, &regs->mrxcnt);
writel(I2C_MBRFIEN | I2C_NAKRCVIEN, &regs->ien);
start = get_timer(0);
while (1) {
if (readl(&regs->ipd) & I2C_NAKRCVIPD) {
writel(I2C_NAKRCVIPD, &regs->ipd);
err = -EREMOTEIO;
}
if (readl(&regs->ipd) & I2C_MBRFIPD) {
writel(I2C_MBRFIPD, &regs->ipd);
break;
}
if (get_timer(start) > I2C_TIMEOUT_MS) {
debug("I2C Read Data Timeout\n");
err = -ETIMEDOUT;
rk_i2c_show_regs(regs);
goto i2c_exit;
}
udelay(1);
}
for (i = 0; i < words_xferred; i++) {
rxdata = readl(&regs->rxdata[i]);
debug("I2c Read RXDATA[%d] = 0x%x\n", i, rxdata);
for (j = 0; j < 4; j++) {
if ((i * 4 + j) == bytes_xferred)
break;
*pbuf++ = (rxdata >> (j * 8)) & 0xff;
}
}
bytes_remain_len -= bytes_xferred;
snd_chunk = true;
debug("I2C Read bytes_remain_len %d\n", bytes_remain_len);
}
i2c_exit:
rk_i2c_send_stop_bit(i2c);
rk_i2c_disable(i2c);
return err;
}
static int rk_i2c_write(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len,
uchar *buf, uint b_len)
{
struct i2c_regs *regs = i2c->regs;
int err;
uchar *pbuf = buf;
uint bytes_remain_len = b_len + r_len + 1;
uint bytes_xferred = 0;
uint words_xferred = 0;
ulong start;
uint txdata;
uint i, j;
debug("rk_i2c_write: chip = %d, reg = %d, r_len = %d, b_len = %d\n",
chip, reg, r_len, b_len);
err = rk_i2c_send_start_bit(i2c);
if (err)
return err;
while (bytes_remain_len) {
if (bytes_remain_len > RK_I2C_FIFO_SIZE)
bytes_xferred = RK_I2C_FIFO_SIZE;
else
bytes_xferred = bytes_remain_len;
words_xferred = DIV_ROUND_UP(bytes_xferred, 4);
for (i = 0; i < words_xferred; i++) {
txdata = 0;
for (j = 0; j < 4; j++) {
if ((i * 4 + j) == bytes_xferred)
break;
if (i == 0 && j == 0 && pbuf == buf) {
txdata |= (chip << 1);
} else if (i == 0 && j <= r_len && pbuf == buf) {
txdata |= (reg &
(0xff << ((j - 1) * 8))) << 8;
} else {
txdata |= (*pbuf++)<<(j * 8);
}
}
writel(txdata, &regs->txdata[i]);
debug("I2c Write TXDATA[%d] = 0x%08x\n", i, txdata);
}
writel(I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TX), &regs->con);
writel(bytes_xferred, &regs->mtxcnt);
writel(I2C_MBTFIEN | I2C_NAKRCVIEN, &regs->ien);
start = get_timer(0);
while (1) {
if (readl(&regs->ipd) & I2C_NAKRCVIPD) {
writel(I2C_NAKRCVIPD, &regs->ipd);
err = -EREMOTEIO;
}
if (readl(&regs->ipd) & I2C_MBTFIPD) {
writel(I2C_MBTFIPD, &regs->ipd);
break;
}
if (get_timer(start) > I2C_TIMEOUT_MS) {
debug("I2C Write Data Timeout\n");
err = -ETIMEDOUT;
rk_i2c_show_regs(regs);
goto i2c_exit;
}
udelay(1);
}
bytes_remain_len -= bytes_xferred;
debug("I2C Write bytes_remain_len %d\n", bytes_remain_len);
}
i2c_exit:
rk_i2c_send_stop_bit(i2c);
rk_i2c_disable(i2c);
return err;
}
static int rockchip_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
int nmsgs)
{
struct rk_i2c *i2c = dev_get_priv(bus);
int ret;
debug("i2c_xfer: %d messages\n", nmsgs);
for (; nmsgs > 0; nmsgs--, msg++) {
debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
if (msg->flags & I2C_M_RD) {
ret = rk_i2c_read(i2c, msg->addr, 0, 0, msg->buf,
msg->len);
} else {
ret = rk_i2c_write(i2c, msg->addr, 0, 0, msg->buf,
msg->len);
}
if (ret) {
debug("i2c_write: error sending\n");
return -EREMOTEIO;
}
}
return 0;
}
int rockchip_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
{
struct rk_i2c *i2c = dev_get_priv(bus);
rk_i2c_set_clk(i2c, speed);
return 0;
}
static int rockchip_i2c_ofdata_to_platdata(struct udevice *bus)
{
struct rk_i2c *priv = dev_get_priv(bus);
int ret;
ret = clk_get_by_index(bus, 0, &priv->clk);
if (ret < 0) {
debug("%s: Could not get clock for %s: %d\n", __func__,
bus->name, ret);
return ret;
}
return 0;
}
static int rockchip_i2c_probe(struct udevice *bus)
{
struct rk_i2c *priv = dev_get_priv(bus);
priv->regs = dev_read_addr_ptr(bus);
return 0;
}
static const struct dm_i2c_ops rockchip_i2c_ops = {
.xfer = rockchip_i2c_xfer,
.set_bus_speed = rockchip_i2c_set_bus_speed,
};
static const struct udevice_id rockchip_i2c_ids[] = {
{ .compatible = "rockchip,rk3066-i2c" },
{ .compatible = "rockchip,rk3188-i2c" },
{ .compatible = "rockchip,rk3288-i2c" },
{ .compatible = "rockchip,rk3328-i2c" },
{ .compatible = "rockchip,rk3399-i2c" },
{ }
};
U_BOOT_DRIVER(i2c_rockchip) = {
.name = "i2c_rockchip",
.id = UCLASS_I2C,
.of_match = rockchip_i2c_ids,
.ofdata_to_platdata = rockchip_i2c_ofdata_to_platdata,
.probe = rockchip_i2c_probe,
.priv_auto_alloc_size = sizeof(struct rk_i2c),
.ops = &rockchip_i2c_ops,
};