[PATCH] i2c: add Rockchip i2c controller support
Sascha Hauer
sha at pengutronix.de
Wed Jan 5 03:20:31 PST 2022
On Mon, Jan 03, 2022 at 01:00:15PM +0100, Ahmad Fatoum wrote:
> For addressing the PMIC on Rockchip platforms, add an i2c controller
> driver. Tested with rk3399 and rk808.
>
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
> drivers/i2c/busses/Kconfig | 8 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-rockchip.c | 472 ++++++++++++++++++++++++++++++
> 3 files changed, 481 insertions(+)
> create mode 100644 drivers/i2c/busses/i2c-rockchip.c
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index c1e76a04096e..a551df537a69 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -62,4 +62,12 @@ config I2C_STM32
> depends on HAVE_CLK
> depends on ARCH_STM32MP || COMPILE_TEST
>
> +config I2C_RK3X
> + tristate "Rockchip RK3xxx I2C adapter"
> + depends on HAVE_CLK
> + depends on ARCH_ROCKCHIP || COMPILE_TEST
> + help
> + Say Y here to include support for the I2C adapter in Rockchip RK3xxx
> + SoCs.
> +
> endmenu
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 34a12fcbea96..d6273f3d8679 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
> obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
> obj-$(CONFIG_I2C_DESIGNWARE) += i2c-designware.o
> obj-$(CONFIG_I2C_STM32) += i2c-stm32.o
> +obj-$(CONFIG_I2C_RK3X) += i2c-rockchip.o
> diff --git a/drivers/i2c/busses/i2c-rockchip.c b/drivers/i2c/busses/i2c-rockchip.c
> new file mode 100644
> index 000000000000..ba7397b19967
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-rockchip.c
> @@ -0,0 +1,472 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * (C) Copyright 2015 Google, Inc
> + *
> + * (C) Copyright 2008-2014 Rockchip Electronics
> + * Peter, Software Engineering, <superpeter.cai at gmail.com>.
> + */
> +
> +#include <common.h>
> +#include <i2c/i2c.h>
> +#include <linux/iopoll.h>
> +#include <errno.h>
> +#include <linux/err.h>
> +#include <driver.h>
> +#include <io.h>
> +#include <linux/clk.h>
> +#include <mfd/syscon.h>
> +#include <regmap.h>
> +#include <linux/sizes.h>
> +
> +struct i2c_regs {
> + u32 con;
> + u32 clkdiv;
> + u32 mrxaddr;
> + u32 mrxraddr;
> + u32 mtxcnt;
> + u32 mrxcnt;
> + u32 ien;
> + u32 ipd;
> + u32 fcnt;
> + u32 reserved0[0x37];
> + u32 txdata[8];
> + u32 reserved1[0x38];
> + u32 rxdata[8];
> +};
> +
> +/* Control register */
> +#define I2C_CON_EN (1 << 0)
> +#define I2C_CON_MOD(mod) ((mod) << 1)
> +#define I2C_MODE_TX 0x00
> +#define I2C_MODE_TRX 0x01
> +#define I2C_MODE_RX 0x02
> +#define I2C_MODE_RRX 0x03
> +#define I2C_CON_MASK (3 << 1)
> +
> +#define I2C_CON_START (1 << 3)
> +#define I2C_CON_STOP (1 << 4)
> +#define I2C_CON_LASTACK (1 << 5)
> +#define I2C_CON_ACTACK (1 << 6)
> +
> +/* Clock dividor register */
s/dividor/divider/
> +#define I2C_CLKDIV_VAL(divl, divh) \
> + (((divl) & 0xffff) | (((divh) << 16) & 0xffff0000))
> +
> +/* the slave address accessed for master rx mode */
> +#define I2C_MRXADDR_SET(vld, addr) (((vld) << 24) | (addr))
> +
> +/* the slave register address accessed for master rx mode */
> +#define I2C_MRXRADDR_SET(vld, raddr) (((vld) << 24) | (raddr))
> +
> +/* interrupt enable register */
> +#define I2C_BTFIEN (1 << 0)
> +#define I2C_BRFIEN (1 << 1)
> +#define I2C_MBTFIEN (1 << 2)
> +#define I2C_MBRFIEN (1 << 3)
> +#define I2C_STARTIEN (1 << 4)
> +#define I2C_STOPIEN (1 << 5)
> +#define I2C_NAKRCVIEN (1 << 6)
> +
> +/* interrupt pending register */
> +#define I2C_BTFIPD (1 << 0)
> +#define I2C_BRFIPD (1 << 1)
> +#define I2C_MBTFIPD (1 << 2)
> +#define I2C_MBRFIPD (1 << 3)
> +#define I2C_STARTIPD (1 << 4)
> +#define I2C_STOPIPD (1 << 5)
> +#define I2C_NAKRCVIPD (1 << 6)
> +#define I2C_IPD_ALL_CLEAN 0x7f
> +
> +/* i2c timerout */
s/timerout/timeout/
> +#define I2C_TIMEOUT (100 * MSECOND)
> +#define I2C_RETRY_COUNT 3
unused
> +
> +/* rk i2c fifo max transfer bytes */
> +#define RK_I2C_FIFO_SIZE 32
> +
> +struct rk_i2c {
> + struct i2c_adapter adapter;
> + struct clk *clk;
> + struct i2c_regs *regs;
> + unsigned int speed;
> +};
> +
> +static inline struct rk_i2c *to_rk_i2c(struct i2c_adapter *adapter)
> +{
> + return container_of(adapter, struct rk_i2c, adapter);
> +}
> +
> +static inline void rk_i2c_get_div(int div, int *divh, int *divl)
> +{
> + *divl = div / 2;
> + if (div % 2 == 0)
> + *divh = div / 2;
Why special case this? DIV_ROUND_UP(div, 2) should work for even numbers
as well.
> + 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)
> +{
> + struct device_d *dev = i2c->adapter.dev.parent;
> + 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);
> +
> + dev_dbg(dev, "rk_i2c_set_clk: i2c rate = %d, scl rate = %d\n", i2c_rate,
> + scl_rate);
> + dev_dbg(dev, "set i2c clk div = %d, divh = %d, divl = %d\n", div, divh, divl);
> + dev_dbg(dev, "set clk(I2C_CLKDIV: 0x%08x)\n", readl(&i2c->regs->clkdiv));
> +}
> +
> +static void rk_i2c_show_regs(struct rk_i2c *i2c)
> +{
> + struct device_d *dev = &i2c->adapter.dev;
> + struct i2c_regs *regs = i2c->regs;
> + int i;
> +
> + dev_dbg(dev, "i2c_con: 0x%08x\n", readl(®s->con));
> + dev_dbg(dev, "i2c_clkdiv: 0x%08x\n", readl(®s->clkdiv));
> + dev_dbg(dev, "i2c_mrxaddr: 0x%08x\n", readl(®s->mrxaddr));
> + dev_dbg(dev, "i2c_mrxraddR: 0x%08x\n", readl(®s->mrxraddr));
> + dev_dbg(dev, "i2c_mtxcnt: 0x%08x\n", readl(®s->mtxcnt));
> + dev_dbg(dev, "i2c_mrxcnt: 0x%08x\n", readl(®s->mrxcnt));
> + dev_dbg(dev, "i2c_ien: 0x%08x\n", readl(®s->ien));
> + dev_dbg(dev, "i2c_ipd: 0x%08x\n", readl(®s->ipd));
> + dev_dbg(dev, "i2c_fcnt: 0x%08x\n", readl(®s->fcnt));
> +
> + for (i = 0; i < 8; i++)
> + dev_dbg(dev, "i2c_txdata%d: 0x%08x\n", i, readl(®s->txdata[i]));
> + for (i = 0; i < 8; i++)
> + dev_dbg(dev, "i2c_rxdata%d: 0x%08x\n", i, readl(®s->rxdata[i]));
> +}
> +
> +static int rk_i2c_send_start_bit(struct rk_i2c *i2c)
> +{
> + struct device_d *dev = &i2c->adapter.dev;
> + struct i2c_regs *regs = i2c->regs;
> + u64 start;
> +
> + dev_dbg(dev, "I2c Send Start bit.\n");
> + writel(I2C_IPD_ALL_CLEAN, ®s->ipd);
> +
> + writel(I2C_CON_EN | I2C_CON_START, ®s->con);
> + writel(I2C_STARTIEN, ®s->ien);
> +
> + for (start = get_time_ns(); !is_timeout(start, I2C_TIMEOUT);) {
> + if (readl(®s->ipd) & I2C_STARTIPD) {
> + writel(I2C_STARTIPD, ®s->ipd);
> + return 0;
> + }
> + udelay(1);
Unnecessary udelay()
> + }
> +
> + dev_dbg(dev, "I2C Send Start Bit Timeout\n");
> + rk_i2c_show_regs(i2c);
> + return -ETIMEDOUT;
> +}
> +
> +static int rk_i2c_send_stop_bit(struct rk_i2c *i2c)
> +{
> + struct device_d *dev = &i2c->adapter.dev;
> + struct i2c_regs *regs = i2c->regs;
> + u64 start;
> +
> + dev_dbg(dev, "I2c Send Stop bit.\n");
> + writel(I2C_IPD_ALL_CLEAN, ®s->ipd);
> +
> + writel(I2C_CON_EN | I2C_CON_STOP, ®s->con);
> + writel(I2C_CON_STOP, ®s->ien);
> +
> + for (start = get_time_ns(); !is_timeout(start, I2C_TIMEOUT);) {
> + if (readl(®s->ipd) & I2C_STOPIPD) {
> + writel(I2C_STOPIPD, ®s->ipd);
> + return 0;
> + }
> + udelay(1);
ditto
> + }
> +
> + dev_dbg(dev, "I2C Send Start Bit Timeout\n");
> + rk_i2c_show_regs(i2c);
> + return -ETIMEDOUT;
> +}
> +
> +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 device_d *dev = &i2c->adapter.dev;
> + struct i2c_regs *regs = i2c->regs;
> + uchar *pbuf = buf;
> + uint bytes_remain_len = b_len;
> + uint bytes_xferred = 0;
> + uint words_xferred = 0;
> + u64 start;
> + uint con = 0;
> + uint rxdata;
> + uint i, j;
> + int err;
> + bool snd_chunk = false;
> +
> + dev_dbg(dev, "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), ®s->mrxaddr);
> + if (r_len == 0) {
> + writel(0, ®s->mrxraddr);
> + } else if (r_len < 4) {
> + writel(I2C_MRXRADDR_SET(r_len, reg), ®s->mrxraddr);
> + } else {
> + dev_dbg(dev, "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;
bytes_xferred = RK_I2C_FIFO_SIZE
> + } 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, ®s->con);
> + writel(bytes_xferred, ®s->mrxcnt);
> + writel(I2C_MBRFIEN | I2C_NAKRCVIEN, ®s->ien);
> +
> + err = -ETIMEDOUT;
> + for (start = get_time_ns(); !is_timeout(start, I2C_TIMEOUT);) {
> + if (readl(®s->ipd) & I2C_NAKRCVIPD) {
> + writel(I2C_NAKRCVIPD, ®s->ipd);
> + err = -EREMOTEIO;
Does it make sense to stay in the loop here?
> + }
> + if (readl(®s->ipd) & I2C_MBRFIPD) {
> + writel(I2C_MBRFIPD, ®s->ipd);
> + err = 0;
> + break;
> + }
> + udelay(1);
Unnecessary udelay().
> + }
> +
> + if (err) {
> + dev_dbg(dev, "I2C Read Data Timeout\n");
> + rk_i2c_show_regs(i2c);
> + goto i2c_exit;
> + }
It's easier to follow when you just exit the loop with
if (is_timeout()) {
err = -ETIMEDOUT;
goto i2c_exit;
}
> +
> + for (i = 0; i < words_xferred; i++) {
> + rxdata = readl(®s->rxdata[i]);
> + dev_dbg(dev, "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;
> + dev_dbg(dev, "I2C Read bytes_remain_len %d\n", bytes_remain_len);
> + }
> +
> +i2c_exit:
> + 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 device_d *dev = &i2c->adapter.dev;
> + 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;
> + u64 start;
> + uint txdata;
> + uint i, j;
> +
> + dev_dbg(dev, "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, ®s->txdata[i]);
> + dev_dbg(dev, "I2c Write TXDATA[%d] = 0x%08x\n", i, txdata);
> + }
> +
> + writel(I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TX), ®s->con);
> + writel(bytes_xferred, ®s->mtxcnt);
> + writel(I2C_MBTFIEN | I2C_NAKRCVIEN, ®s->ien);
> +
> + err = -ETIMEDOUT;
> + for (start = get_time_ns(); !is_timeout(start, I2C_TIMEOUT);) {
> + if (readl(®s->ipd) & I2C_NAKRCVIPD) {
> + writel(I2C_NAKRCVIPD, ®s->ipd);
> + err = -EREMOTEIO;
> + }
Same as above, need to stay in the loop here?
> + if (readl(®s->ipd) & I2C_MBTFIPD) {
> + writel(I2C_MBTFIPD, ®s->ipd);
> + err = 0;
> + break;
> + }
> + udelay(1);
Drop the udelay()
> + }
> +
> + if (err) {
> + dev_dbg(dev, "I2C Write Data Timeout\n");
> + rk_i2c_show_regs(i2c);
> + goto i2c_exit;
> + }
Test for timeout in the loop.
> +
> + bytes_remain_len -= bytes_xferred;
> + dev_dbg(dev, "I2C Write bytes_remain_len %d\n", bytes_remain_len);
> + }
> +
> +i2c_exit:
> + rk_i2c_disable(i2c);
> +
> + return err;
> +}
> +
> +static int rockchip_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msg,
> + int nmsgs)
> +{
> + struct rk_i2c *i2c = to_rk_i2c(adapter);
> + struct device_d *dev = &adapter->dev;
> + int ret;
> +
> + dev_dbg(dev, "i2c_xfer: %d messages\n", nmsgs);
> + for (; nmsgs > 0; nmsgs--, msg++) {
> + dev_dbg(dev, "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) {
> + dev_dbg(dev, "i2c_write: error sending\n");
> + return -EREMOTEIO;
Print the error code? Forward the error?
> + }
> + }
> +
> + rk_i2c_send_stop_bit(i2c);
> + rk_i2c_disable(i2c);
> +
> + return 0;
> +}
> +
> +static int rk_i2c_probe(struct device_d *dev)
> +{
> + struct device_node *np = dev->device_node;
> + struct resource *iores;
> + struct rk_i2c *i2c;
> + unsigned bitrate;
> +
> + iores = dev_request_mem_resource(dev, 0);
> + if (IS_ERR(iores))
> + return PTR_ERR(iores);
> +
> + i2c = kzalloc(sizeof(struct rk_i2c), GFP_KERNEL);
> + if (!i2c)
> + return -ENOMEM;
> +
> + dev->priv = i2c;
> + i2c->regs = IOMEM(iores->start);
> +
> + /* Only one clock to use for bus clock and peripheral clock */
> + i2c->clk = clk_get(dev, NULL);
> + if (IS_ERR(i2c->clk))
> + return dev_err_probe(dev, PTR_ERR(i2c->clk), "Can't get bus clk\n");
> +
> + /* Setup i2c_fsl driver structure */
copy/paste, it's not i2c_fsl
> + i2c->adapter.master_xfer = rockchip_i2c_xfer;
> + i2c->adapter.nr = dev->id;
> + i2c->adapter.dev.parent = dev;
> + i2c->adapter.dev.device_node = np;
> +
> + /* Set up clock divider */
> + bitrate = 100000;
> + of_property_read_u32(np, "clock-frequency", &bitrate);
> +
> + rk_i2c_set_clk(i2c, bitrate);
> +
> + return i2c_add_numbered_adapter(&i2c->adapter);
> +}
> +
> +static const struct of_device_id rk_i2c_match[] = {
> + { .compatible = "rockchip,rv1108-i2c" },
> + { .compatible = "rockchip,rk3228-i2c" },
> + { .compatible = "rockchip,rk3288-i2c" },
> + { .compatible = "rockchip,rk3399-i2c" },
> + {},
> +};
> +
> +static struct driver_d rk_i2c_driver = {
> + .name = "rk3x-i2c",
> + .of_compatible = rk_i2c_match,
> + .probe = rk_i2c_probe,
> +};
> +coredevice_platform_driver(rk_i2c_driver);
> --
> 2.30.2
>
>
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