ramips: add mt7621/3/8 support to the I2C driver

Signed-off-by: John Crispin <blogic@openwrt.org>

Backport of r46959

git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@47095 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 66 insertions, 38 deletions

diff --git a/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch b/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch
index 3064b17da5..5618652dff 100644
--- a/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch
+++ b/target/linux/ramips/patches-3.18/0052-i2c-MIPS-adds-ralink-I2C-driver.patch
@@ -68,7 +68,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
  obj-$(CONFIG_I2C_RK3X)		+= i2c-rk3x.o
 --- /dev/null
 +++ b/drivers/i2c/busses/i2c-ralink.c
-@@ -0,0 +1,299 @@
+@@ -0,0 +1,327 @@
 +/*
 + * drivers/i2c/busses/i2c-ralink.c
 + *
@@ -97,6 +97,7 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +#include <linux/init.h>
 +#include <linux/errno.h>
 +#include <linux/platform_device.h>
++#include <linux/of_platform.h>
 +#include <linux/i2c.h>
 +#include <linux/io.h>
 +#include <linux/err.h>
@@ -112,6 +113,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +#define REG_STATUS_REG		0x18
 +#define REG_STARTXFR_REG	0x1C
 +#define REG_BYTECNT_REG		0x20
++#define REG_SM0CFG2		0x28
++#define REG_SM0CTL0		0x40
 +
 +#define I2C_STARTERR		BIT(4)
 +#define I2C_ACKERR		BIT(3)
@@ -122,8 +125,6 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +#define I2C_DEVADLEN_7		(6 << 2)
 +#define I2C_ADDRDIS		BIT(1)
 +
-+#define I2C_RETRY		0x1000
-+
 +#define CLKDIV_VALUE		200 // clock rate is 40M, 40M / (200*2) = 100k (standard i2c bus rate).
 +//#define CLKDIV_VALUE		50 // clock rate is 40M, 40M / (50*2) = 400k (fast i2c bus rate).
 +
@@ -131,8 +132,23 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +#define WRITE_CMD		0x00
 +#define READ_BLOCK              64
 +
++#define SM0CTL0_OD		BIT(31)
++#define SM0CTL0_VTRIG		BIT(28)
++#define SM0CTL0_OUTHI		BIT(6)
++#define SM0CTL0_STRETCH		BIT(1)
++#define SM0CTL0_DEFAULT		(SM0CTL0_OD | SM0CTL0_VTRIG | SM0CTL0_OUTHI | SM0CTL0_STRETCH)
++
++/* timeout waiting for I2C devices to respond (clock streching) */
++#define RT_I2C_TIMEOUT (msecs_to_jiffies(1000))
++
++enum {
++	I2C_TYPE_RALINK,
++	I2C_TYPE_MEDIATEK,
++};
++
 +static void __iomem *membase;
 +static struct i2c_adapter *adapter;
++static int hw_type;
 +
 +static void rt_i2c_w32(u32 val, unsigned reg)
 +{
@@ -151,38 +167,48 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +
 +static inline int rt_i2c_wait_rx_done(void)
 +{
-+	int retries = I2C_RETRY;
++	unsigned long timeout;
++
++	timeout = jiffies + RT_I2C_TIMEOUT;
 +
 +	do {
-+		if (!retries--)
-+			break;
-+	} while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
++		if (time_after(jiffies, timeout))
++			return (-ETIMEDOUT);
++
++	} while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
 +
-+	return (retries < 0) ? -ETIMEDOUT : 0;
++	return 0;
 +}
 +
 +static inline int rt_i2c_wait_idle(void)
 +{
-+	int retries = I2C_RETRY;
++	unsigned long timeout;
++
++	timeout = jiffies + RT_I2C_TIMEOUT;
 +
 +	do {
-+		if (!retries--)
-+			break;
-+	} while(rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
++		if (time_after(jiffies, timeout)) {
++			printk("i2c-read line busy\n");
++			return 1;
++		}
++	} while (rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
 +
-+	return (retries < 0);
++	return 0;
 +}
 +
 +static inline int rt_i2c_wait_tx_done(void)
 +{
-+	int retries = I2C_RETRY;
++	unsigned long timeout;
++
++	timeout = jiffies + RT_I2C_TIMEOUT;
 +
 +	do {
-+		if (!retries--)
-+			break;
-+	} while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
++		if (time_after(jiffies, timeout))
++			return (-ETIMEDOUT);
++
++	} while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
 +
-+	return (retries < 0) ? -ETIMEDOUT : 0;
++	return 0;
 +}
 +
 +static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
@@ -199,10 +225,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +
 +	if (msg->flags & I2C_M_RD) {
 +		for (i = 0; i < nblock; i++) {
-+	                if (rt_i2c_wait_idle()) {
-+		            printk("i2c-read line busy\n");
++	                if (rt_i2c_wait_idle())
 +				return -ETIMEDOUT;
-+			}
 +			rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
 +			rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
 +			for (j = 0; j < READ_BLOCK; j++) {
@@ -214,10 +238,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +			}
 +		}
 +
-+		if (rt_i2c_wait_idle()) {
-+			printk("i2c-read line busy\n");
++		if (rt_i2c_wait_idle())
 +			return -ETIMEDOUT;
-+		}
 +		if (rem) {
 +			rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
 +			rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
@@ -231,10 +253,8 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +			msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
 +		}
 +	} else {
-+		if (rt_i2c_wait_idle()) {
-+			printk("i2c-write line busy\n");
++		if (rt_i2c_wait_idle())
 +			return -ETIMEDOUT;
-+		}
 +		rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
 +		for (i = 0; i < msg->len; i++) {
 +			rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
@@ -255,16 +275,19 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +	int i = 0;
 +	int ret = 0;
 +
-+	if (rt_i2c_wait_idle()) {
-+		printk("i2c-master_xfer line busy\n");
++	if (rt_i2c_wait_idle())
 +		return -ETIMEDOUT;
-+	}
 +
 +	device_reset(a->dev.parent);
 +
 +	rt_i2c_w32(m->addr, REG_DEVADDR_REG);
 +	rt_i2c_w32(I2C_DEVADLEN_7 | I2C_ADDRDIS, REG_CONFIG_REG);
-+	rt_i2c_w32(CLKDIV_VALUE, REG_CLKDIV_REG);
++	if (hw_type == I2C_TYPE_RALINK) {
++		rt_i2c_w32(CLKDIV_VALUE, REG_CLKDIV_REG);
++	} else {
++		rt_i2c_w32((CLKDIV_VALUE << 16) | SM0CTL0_DEFAULT, REG_SM0CTL0);
++		rt_i2c_w32(1, REG_SM0CFG2);
++	}
 +
 +	for (i = 0; i < n && !ret; i++) {
 +		ret = rt_i2c_handle_msg(a, &m[i]);
@@ -287,11 +310,23 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +	.functionality	= rt_i2c_func,
 +};
 +
++static const struct of_device_id i2c_rt_dt_ids[] = {
++	{ .compatible = "ralink,rt2880-i2c", .data = (void *) I2C_TYPE_RALINK },
++	{ .compatible = "mediatek,mt7628-i2c", .data = (void *) I2C_TYPE_MEDIATEK },
++	{ /* sentinel */ }
++};
++
++MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
++
 +static int rt_i2c_probe(struct platform_device *pdev)
 +{
 +	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++	const struct of_device_id *match;
 +	int ret;
 +
++	match = of_match_device(i2c_rt_dt_ids, &pdev->dev);
++	hw_type = (int) match->data;
++
 +	if (!res) {
 +		dev_err(&pdev->dev, "no memory resource found\n");
 +		return -ENODEV;
@@ -334,13 +369,6 @@ Signed-off-by: John Crispin <blogic@openwrt.org>
 +	return 0;
 +}
 +
-+static const struct of_device_id i2c_rt_dt_ids[] = {
-+	{ .compatible = "ralink,rt2880-i2c", },
-+	{ /* sentinel */ }
-+};
-+
-+MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
-+
 +static struct platform_driver rt_i2c_driver = {
 +	.probe		= rt_i2c_probe,
 +	.remove		= rt_i2c_remove,