+};
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
-@@ -806,6 +806,10 @@ config I2C_RK3X
+@@ -806,6 +806,11 @@ config I2C_RK3X
This driver can also be built as a module. If so, the module will
be called i2c-rk3x.
+config I2C_RALINK
+ tristate "Ralink I2C Controller"
++ depends on RALINK && !SOC_MT7621
+ select OF_I2C
+
config HAVE_S3C2410_I2C
obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o
--- /dev/null
+++ b/drivers/i2c/busses/i2c-ralink.c
-@@ -0,0 +1,327 @@
+@@ -0,0 +1,435 @@
+/*
+ * drivers/i2c/busses/i2c-ralink.c
+ *
+ * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
++ * Copyright (C) 2016 Michael Lee <igvtee@gmail.com>
+ *
+ * Improve driver for i2cdetect from i2c-tools to detect i2c devices on the bus.
+ * (C) 2014 Sittisak <sittisaks@hotmail.com>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/err.h>
-+
-+#include <asm/mach-ralink/ralink_regs.h>
++#include <linux/clk.h>
+
+#define REG_CONFIG_REG 0x00
+#define REG_CLKDIV_REG 0x04
+#define REG_STATUS_REG 0x18
+#define REG_STARTXFR_REG 0x1C
+#define REG_BYTECNT_REG 0x20
-+#define REG_SM0CFG2 0x28
-+#define REG_SM0CTL0 0x40
+
++/* REG_CONFIG_REG */
++#define I2C_ADDRLEN_OFFSET 5
++#define I2C_DEVADLEN_OFFSET 2
++#define I2C_ADDRLEN_MASK 0x3
++#define I2C_ADDR_DIS BIT(1)
++#define I2C_DEVADDR_DIS BIT(0)
++#define I2C_ADDRLEN_8 (7 << I2C_ADDRLEN_OFFSET)
++#define I2C_DEVADLEN_7 (6 << I2C_DEVADLEN_OFFSET)
++#define I2C_CONF_DEFAULT (I2C_ADDRLEN_8 | I2C_DEVADLEN_7)
++
++/* REG_CLKDIV_REG */
++#define I2C_CLKDIV_MASK 0xffff
++
++/* REG_DEVADDR_REG */
++#define I2C_DEVADDR_MASK 0x7f
++
++/* REG_ADDR_REG */
++#define I2C_ADDR_MASK 0xff
++
++/* REG_STATUS_REG */
+#define I2C_STARTERR BIT(4)
+#define I2C_ACKERR BIT(3)
+#define I2C_DATARDY BIT(2)
+#define I2C_SDOEMPTY BIT(1)
+#define I2C_BUSY BIT(0)
+
-+#define I2C_DEVADLEN_7 (6 << 2)
-+#define I2C_ADDRDIS BIT(1)
++/* REG_STARTXFR_REG */
++#define NOSTOP_CMD BIT(2)
++#define NODATA_CMD BIT(1)
++#define READ_CMD BIT(0)
+
-+#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).
-+
-+#define READ_CMD 0x01
-+#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)
++/* REG_BYTECNT_REG */
++#define BYTECNT_MAX 64
++#define SET_BYTECNT(x) (x - 1)
+
+/* timeout waiting for I2C devices to respond (clock streching) */
-+#define RT_I2C_TIMEOUT (msecs_to_jiffies(1000))
-+
-+enum {
-+ I2C_TYPE_RALINK,
-+ I2C_TYPE_MEDIATEK,
++#define TIMEOUT_MS 1000
++#define DELAY_INTERVAL_US 100
++
++struct rt_i2c {
++ void __iomem *base;
++ struct clk *clk;
++ struct device *dev;
++ struct i2c_adapter adap;
++ u32 cur_clk;
++ u32 clk_div;
++ u32 flags;
+};
+
-+static void __iomem *membase;
-+static struct i2c_adapter *adapter;
-+static int hw_type;
-+
-+static void rt_i2c_w32(u32 val, unsigned reg)
++static void rt_i2c_w32(struct rt_i2c *i2c, u32 val, unsigned reg)
+{
-+ iowrite32(val, membase + reg);
++ iowrite32(val, i2c->base + reg);
+}
+
-+static u32 rt_i2c_r32(unsigned reg)
++static u32 rt_i2c_r32(struct rt_i2c *i2c, unsigned reg)
+{
-+ return ioread32(membase + reg);
++ return ioread32(i2c->base + reg);
+}
+
-+static inline int rt_i2c_get_ack(void)
++static int poll_down_timeout(void __iomem *addr, u32 mask)
+{
-+ return (rt_i2c_r32(REG_STATUS_REG) & I2C_ACKERR) ? -EIO : 0;
-+}
-+
-+static inline int rt_i2c_wait_rx_done(void)
-+{
-+ unsigned long timeout;
-+
-+ timeout = jiffies + RT_I2C_TIMEOUT;
++ unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
+
+ do {
-+ if (time_after(jiffies, timeout))
-+ return (-ETIMEDOUT);
++ if (!(readl_relaxed(addr) & mask))
++ return 0;
+
-+ } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
++ usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
++ } while (time_before(jiffies, timeout));
+
-+ return 0;
++ return (readl_relaxed(addr) & mask) ? -EAGAIN : 0;
+}
+
-+static inline int rt_i2c_wait_idle(void)
++static int rt_i2c_wait_idle(struct rt_i2c *i2c)
+{
-+ unsigned long timeout;
++ int ret;
+
-+ timeout = jiffies + RT_I2C_TIMEOUT;
++ ret = poll_down_timeout(i2c->base + REG_STATUS_REG, I2C_BUSY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "idle err(%d)\n", ret);
+
-+ do {
-+ if (time_after(jiffies, timeout)) {
-+ printk("i2c-read line busy\n");
-+ return 1;
-+ }
-+ } while (rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
-+
-+ return 0;
++ return ret;
+}
+
-+static inline int rt_i2c_wait_tx_done(void)
++static int poll_up_timeout(void __iomem *addr, u32 mask)
+{
-+ unsigned long timeout;
-+
-+ timeout = jiffies + RT_I2C_TIMEOUT;
++ unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
++ u32 status;
+
+ do {
-+ if (time_after(jiffies, timeout))
-+ return (-ETIMEDOUT);
++ status = readl_relaxed(addr);
+
-+ } while (!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
++ /* check error status */
++ if (status & I2C_STARTERR)
++ return -EAGAIN;
++ else if (status & I2C_ACKERR)
++ return -ENXIO;
++ else if (status & mask)
++ return 0;
+
-+ return 0;
++ usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
++ } while (time_before(jiffies, timeout));
++
++ return -ETIMEDOUT;
+}
+
-+static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
++static int rt_i2c_wait_rx_done(struct rt_i2c *i2c)
+{
-+ int i = 0, j = 0, pos = 0;
-+ int nblock = msg->len / READ_BLOCK;
-+ int rem = msg->len % READ_BLOCK;
-+ int ret = 0;
-+
-+ if (msg->flags & I2C_M_TEN) {
-+ printk("10 bits addr not supported\n");
-+ return -EINVAL;
-+ }
-+
-+ if (msg->flags & I2C_M_RD) {
-+ for (i = 0; i < nblock; i++) {
-+ 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++) {
-+ if (rt_i2c_wait_rx_done() < 0)
-+ ret = rt_i2c_wait_rx_done();
-+ if (rt_i2c_get_ack() < 0)
-+ ret = rt_i2c_get_ack();
-+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
-+ }
-+ }
-+
-+ 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);
-+ }
-+ for (i = 0; i < rem; i++) {
-+ if (rt_i2c_wait_rx_done() < 0)
-+ ret = rt_i2c_wait_rx_done();
-+ if (rt_i2c_get_ack() < 0)
-+ ret = rt_i2c_get_ack();
++ int ret;
+
-+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
-+ }
-+ } else {
-+ 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);
-+ rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
-+
-+ if (rt_i2c_wait_tx_done() < 0)
-+ ret = rt_i2c_wait_tx_done();
-+ if (rt_i2c_get_ack() < 0)
-+ ret = rt_i2c_get_ack();
-+ }
-+ }
++ ret = poll_up_timeout(i2c->base + REG_STATUS_REG, I2C_DATARDY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "rx err(%d)\n", ret);
+
+ return ret;
+}
+
-+static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
++static int rt_i2c_wait_tx_done(struct rt_i2c *i2c)
+{
-+ int i = 0;
-+ int ret = 0;
++ int ret;
+
-+ if (rt_i2c_wait_idle())
-+ return -ETIMEDOUT;
++ ret = poll_up_timeout(i2c->base + REG_STATUS_REG, I2C_SDOEMPTY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "tx err(%d)\n", ret);
+
-+ device_reset(a->dev.parent);
++ return ret;
++}
+
-+ rt_i2c_w32(m->addr, REG_DEVADDR_REG);
-+ rt_i2c_w32(I2C_DEVADLEN_7 | I2C_ADDRDIS, REG_CONFIG_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);
-+ }
++static void rt_i2c_reset(struct rt_i2c *i2c)
++{
++ device_reset(i2c->adap.dev.parent);
++ barrier();
++ rt_i2c_w32(i2c, i2c->clk_div, REG_CLKDIV_REG);
++}
++
++static void rt_i2c_dump_reg(struct rt_i2c *i2c)
++{
++ dev_dbg(i2c->dev, "conf %08x, clkdiv %08x, devaddr %08x, " \
++ "addr %08x, dataout %08x, datain %08x, " \
++ "status %08x, startxfr %08x, bytecnt %08x\n",
++ rt_i2c_r32(i2c, REG_CONFIG_REG),
++ rt_i2c_r32(i2c, REG_CLKDIV_REG),
++ rt_i2c_r32(i2c, REG_DEVADDR_REG),
++ rt_i2c_r32(i2c, REG_ADDR_REG),
++ rt_i2c_r32(i2c, REG_DATAOUT_REG),
++ rt_i2c_r32(i2c, REG_DATAIN_REG),
++ rt_i2c_r32(i2c, REG_STATUS_REG),
++ rt_i2c_r32(i2c, REG_STARTXFR_REG),
++ rt_i2c_r32(i2c, REG_BYTECNT_REG));
++}
+
-+ for (i = 0; i < n && !ret; i++) {
-+ ret = rt_i2c_handle_msg(a, &m[i]);
++static int rt_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
++ int num)
++{
++ struct rt_i2c *i2c;
++ struct i2c_msg *pmsg;
++ unsigned char addr;
++ int i, j, ret;
++ u32 cmd;
++
++ i2c = i2c_get_adapdata(adap);
++
++ for (i = 0; i < num; i++) {
++ pmsg = &msgs[i];
++ if (i == (num - 1))
++ cmd = 0;
++ else
++ cmd = NOSTOP_CMD;
++
++ dev_dbg(i2c->dev, "addr: 0x%x, len: %d, flags: 0x%x, stop: %d\n",
++ pmsg->addr, pmsg->len, pmsg->flags,
++ (cmd == 0)? 1 : 0);
++
++ /* wait hardware idle */
++ if ((ret = rt_i2c_wait_idle(i2c)))
++ goto err_timeout;
++
++ if (pmsg->flags & I2C_M_TEN) {
++ rt_i2c_w32(i2c, I2C_CONF_DEFAULT, REG_CONFIG_REG);
++ /* 10 bits address */
++ addr = 0x78 | ((pmsg->addr >> 8) & 0x03);
++ rt_i2c_w32(i2c, addr & I2C_DEVADDR_MASK,
++ REG_DEVADDR_REG);
++ rt_i2c_w32(i2c, pmsg->addr & I2C_ADDR_MASK,
++ REG_ADDR_REG);
++ } else {
++ rt_i2c_w32(i2c, I2C_CONF_DEFAULT | I2C_ADDR_DIS,
++ REG_CONFIG_REG);
++ /* 7 bits address */
++ rt_i2c_w32(i2c, pmsg->addr & I2C_DEVADDR_MASK,
++ REG_DEVADDR_REG);
++ }
+
-+ if (ret < 0) {
-+ return ret;
++ /* buffer length */
++ if (pmsg->len == 0)
++ cmd |= NODATA_CMD;
++ else
++ rt_i2c_w32(i2c, SET_BYTECNT(pmsg->len),
++ REG_BYTECNT_REG);
++
++ j = 0;
++ if (pmsg->flags & I2C_M_RD) {
++ cmd |= READ_CMD;
++ /* start transfer */
++ barrier();
++ rt_i2c_w32(i2c, cmd, REG_STARTXFR_REG);
++ do {
++ /* wait */
++ if ((ret = rt_i2c_wait_rx_done(i2c)))
++ goto err_timeout;
++ /* read data */
++ if (pmsg->len)
++ pmsg->buf[j] = rt_i2c_r32(i2c,
++ REG_DATAIN_REG);
++ j++;
++ } while (j < pmsg->len);
++ } else {
++ do {
++ /* write data */
++ if (pmsg->len)
++ rt_i2c_w32(i2c, pmsg->buf[j],
++ REG_DATAOUT_REG);
++ /* start transfer */
++ if (j == 0) {
++ barrier();
++ rt_i2c_w32(i2c, cmd, REG_STARTXFR_REG);
++ }
++ /* wait */
++ if ((ret = rt_i2c_wait_tx_done(i2c)))
++ goto err_timeout;
++ j++;
++ } while (j < pmsg->len);
+ }
+ }
++ /* the return value is number of executed messages */
++ ret = i;
++
++ return ret;
+
-+ return n;
++err_timeout:
++ rt_i2c_dump_reg(i2c);
++ rt_i2c_reset(i2c);
++ return ret;
+}
+
+static u32 rt_i2c_func(struct i2c_adapter *a)
+};
+
+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 },
++ { .compatible = "ralink,rt2880-i2c" },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
+
++static struct i2c_adapter_quirks rt_i2c_quirks = {
++ .max_write_len = BYTECNT_MAX,
++ .max_read_len = BYTECNT_MAX,
++};
++
++static int rt_i2c_init(struct rt_i2c *i2c)
++{
++ u32 reg;
++
++ /* i2c_sclk = periph_clk / ((2 * clk_div) + 5) */
++ i2c->clk_div = (clk_get_rate(i2c->clk) - (5 * i2c->cur_clk)) /
++ (2 * i2c->cur_clk);
++ if (i2c->clk_div < 8)
++ i2c->clk_div = 8;
++ if (i2c->clk_div > I2C_CLKDIV_MASK)
++ i2c->clk_div = I2C_CLKDIV_MASK;
++
++ /* check support combinde/repeated start message */
++ rt_i2c_w32(i2c, NOSTOP_CMD, REG_STARTXFR_REG);
++ reg = rt_i2c_r32(i2c, REG_STARTXFR_REG) & NOSTOP_CMD;
++
++ rt_i2c_reset(i2c);
++
++ return reg;
++}
++
+static int rt_i2c_probe(struct platform_device *pdev)
+{
-+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ struct resource *res;
++ struct rt_i2c *i2c;
++ struct i2c_adapter *adap;
+ const struct of_device_id *match;
-+ int ret;
++ int ret, restart;
+
+ match = of_match_device(i2c_rt_dt_ids, &pdev->dev);
-+ hw_type = (int) match->data;
+
++ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no memory resource found\n");
+ return -ENODEV;
+ }
+
-+ adapter = devm_kzalloc(&pdev->dev, sizeof(struct i2c_adapter), GFP_KERNEL);
-+ if (!adapter) {
++ i2c = devm_kzalloc(&pdev->dev, sizeof(struct rt_i2c), GFP_KERNEL);
++ if (!i2c) {
+ dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
+ return -ENOMEM;
+ }
+
-+ membase = devm_ioremap_resource(&pdev->dev, res);
-+ if (IS_ERR(membase))
-+ return PTR_ERR(membase);
-+
-+ strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
-+ adapter->owner = THIS_MODULE;
-+ adapter->nr = pdev->id;
-+ adapter->timeout = HZ;
-+ adapter->algo = &rt_i2c_algo;
-+ adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-+ adapter->dev.parent = &pdev->dev;
-+ adapter->dev.of_node = pdev->dev.of_node;
-+
-+ ret = i2c_add_numbered_adapter(adapter);
-+ if (ret)
-+ return ret;
++ i2c->base = devm_ioremap_resource(&pdev->dev, res);
++ if (IS_ERR(i2c->base))
++ return PTR_ERR(i2c->base);
+
-+ platform_set_drvdata(pdev, adapter);
++ i2c->clk = devm_clk_get(&pdev->dev, NULL);
++ if (IS_ERR(i2c->clk)) {
++ dev_err(&pdev->dev, "no clock defined\n");
++ return -ENODEV;
++ }
++ clk_prepare_enable(i2c->clk);
++ i2c->dev = &pdev->dev;
++
++ if (of_property_read_u32(pdev->dev.of_node,
++ "clock-frequency", &i2c->cur_clk))
++ i2c->cur_clk = 100000;
++
++ adap = &i2c->adap;
++ adap->owner = THIS_MODULE;
++ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
++ adap->algo = &rt_i2c_algo;
++ adap->retries = 3;
++ adap->dev.parent = &pdev->dev;
++ i2c_set_adapdata(adap, i2c);
++ adap->dev.of_node = pdev->dev.of_node;
++ strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
++ adap->quirks = &rt_i2c_quirks;
++
++ platform_set_drvdata(pdev, i2c);
++
++ restart = rt_i2c_init(i2c);
++
++ ret = i2c_add_adapter(adap);
++ if (ret < 0) {
++ dev_err(&pdev->dev, "failed to add adapter\n");
++ clk_disable_unprepare(i2c->clk);
++ return ret;
++ }
+
-+ dev_info(&pdev->dev, "loaded\n");
++ dev_info(&pdev->dev, "clock %uKHz, re-start %ssupport\n",
++ i2c->cur_clk/1000, restart ? "" : "not ");
+
-+ return 0;
++ return ret;
+}
+
+static int rt_i2c_remove(struct platform_device *pdev)
+{
-+ platform_set_drvdata(pdev, NULL);
++ struct rt_i2c *i2c = platform_get_drvdata(pdev);
++
++ i2c_del_adapter(&i2c->adap);
++ clk_disable_unprepare(i2c->clk);
+
+ return 0;
+}
+{
+ platform_driver_unregister(&rt_i2c_driver);
+}
-+
-+module_exit (i2c_rt_exit);
++module_exit(i2c_rt_exit);
+
+MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
+MODULE_DESCRIPTION("Ralink I2c host driver");
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
-@@ -810,6 +810,10 @@ config I2C_RALINK
- tristate "Ralink I2C Controller"
+@@ -811,6 +811,11 @@ config I2C_RALINK
+ depends on RALINK && !SOC_MT7621
select OF_I2C
+config I2C_MT7621
-+ tristate "MT7621 I2C Controller"
++ tristate "MT7621/MT7628 I2C Controller"
++ depends on RALINK && (SOC_MT7620 || SOC_MT7621)
+ select OF_I2C
+
config HAVE_S3C2410_I2C
obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mt7621.c
-@@ -0,0 +1,303 @@
+@@ -0,0 +1,433 @@
+/*
+ * drivers/i2c/busses/i2c-mt7621.c
+ *
+ * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
++ * Copyright (C) 2016 Michael Lee <igvtee@gmail.com>
+ *
+ * Improve driver for i2cdetect from i2c-tools to detect i2c devices on the bus.
+ * (C) 2014 Sittisak <sittisaks@hotmail.com>
+#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>
++#include <linux/clk.h>
++
++#define REG_SM0CFG0 0x08
++#define REG_SM0DOUT 0x10
++#define REG_SM0DIN 0x14
++#define REG_SM0ST 0x18
++#define REG_SM0AUTO 0x1C
++#define REG_SM0CFG1 0x20
++#define REG_SM0CFG2 0x28
++#define REG_SM0CTL0 0x40
++#define REG_SM0CTL1 0x44
++#define REG_SM0D0 0x50
++#define REG_SM0D1 0x54
++#define REG_PINTEN 0x5C
++#define REG_PINTST 0x60
++#define REG_PINTCL 0x64
++
++/* REG_SM0CFG0 */
++#define I2C_DEVADDR_MASK 0x7f
++
++/* REG_SM0ST */
++#define I2C_DATARDY BIT(2)
++#define I2C_SDOEMPTY BIT(1)
++#define I2C_BUSY BIT(0)
++
++/* REG_SM0AUTO */
++#define READ_CMD BIT(0)
++
++/* REG_SM0CFG1 */
++#define BYTECNT_MAX 64
++#define SET_BYTECNT(x) (x - 1)
++
++/* REG_SM0CFG2 */
++#define AUTOMODE_EN BIT(0)
++
++/* REG_SM0CTL0 */
++#define ODRAIN_HIGH_SM0 BIT(31)
++#define VSYNC_SHIFT 28
++#define VSYNC_MASK 0x3
++#define VSYNC_PULSE (0x1 << VSYNC_SHIFT)
++#define VSYNC_RISING (0x2 << VSYNC_SHIFT)
++#define CLK_DIV_SHIFT 16
++#define CLK_DIV_MASK 0xfff
++#define DEG_CNT_SHIFT 8
++#define DEG_CNT_MASK 0xff
++#define WAIT_HIGH BIT(6)
++#define DEG_EN BIT(5)
++#define CS_STATUA BIT(4)
++#define SCL_STATUS BIT(3)
++#define SDA_STATUS BIT(2)
++#define SM0_EN BIT(1)
++#define SCL_STRECH BIT(0)
++
++/* REG_SM0CTL1 */
++#define ACK_SHIFT 16
++#define ACK_MASK 0xff
++#define PGLEN_SHIFT 8
++#define PGLEN_MASK 0x7
++#define SM0_MODE_SHIFT 4
++#define SM0_MODE_MASK 0x7
++#define SM0_MODE_START 0x1
++#define SM0_MODE_WRITE 0x2
++#define SM0_MODE_STOP 0x3
++#define SM0_MODE_READ_NACK 0x4
++#define SM0_MODE_READ_ACK 0x5
++#define SM0_TRI_BUSY BIT(0)
++
++/* timeout waiting for I2C devices to respond (clock streching) */
++#define TIMEOUT_MS 1000
++#define DELAY_INTERVAL_US 100
++
++struct mtk_i2c {
++ void __iomem *base;
++ struct clk *clk;
++ struct device *dev;
++ struct i2c_adapter adap;
++ u32 cur_clk;
++ u32 clk_div;
++ u32 flags;
++};
+
-+#include <asm/mach-ralink/ralink_regs.h>
-+
-+#define REG_CONFIG_REG 0x00
-+#define REG_CLKDIV_REG 0x04
-+#define REG_DEVADDR_REG 0x08
-+#define REG_ADDR_REG 0x0C
-+#define REG_DATAOUT_REG 0x10
-+#define REG_DATAIN_REG 0x14
-+#define REG_STATUS_REG 0x18
-+#define REG_STARTXFR_REG 0x1C
-+#define REG_BYTECNT_REG 0x20
-+#define REG_SM0_IS_AUTOMODE 0x28
-+#define REG_SM0CTL0 0x40
-+
-+
-+#define I2C_STARTERR 0x10
-+#define I2C_ACKERR 0x08
-+#define I2C_DATARDY 0x04
-+#define I2C_SDOEMPTY 0x02
-+#define I2C_BUSY 0x01
-+
-+/* I2C_CFG register bit field */
-+#define I2C_CFG_ADDRLEN_8 (7<<5) /* 8 bits */
-+#define I2C_CFG_DEVADLEN_7 (6<<2)
-+#define I2C_CFG_ADDRDIS BIT(1)
-+#define I2C_CFG_DEVADDIS BIT(0)
-+
-+#define I2C_CFG_DEFAULT (I2C_CFG_ADDRLEN_8 | \
-+ I2C_CFG_DEVADLEN_7 | \
-+ I2C_CFG_ADDRDIS)
-+
-+#define I2C_RETRY 0x1000
-+
-+#define CLKDIV_VALUE 333
-+#define i2c_busy_loop (CLKDIV_VALUE*30)
-+
-+#define READ_CMD 0x01
-+#define WRITE_CMD 0x00
-+#define READ_BLOCK 16
-+
-+#define SM0_ODRAIN BIT(31)
-+#define SM0_VSYNC_MODE BIT(28)
-+#define SM0_CLK_DIV (CLKDIV_VALUE << 16)
-+#define SM0_WAIT_LEVEL BIT(6)
-+#define SM0_EN BIT(1)
-+
-+#define SM0_CFG_DEFUALT (SM0_ODRAIN | SM0_VSYNC_MODE | \
-+ SM0_CLK_DIV | SM0_WAIT_LEVEL | \
-+ SM0_EN)
-+/***********************************************************/
-+
-+static void __iomem *membase;
-+static struct i2c_adapter *adapter;
-+
-+static void rt_i2c_w32(u32 val, unsigned reg)
++static void mtk_i2c_w32(struct mtk_i2c *i2c, u32 val, unsigned reg)
+{
-+ iowrite32(val, membase + reg);
++ iowrite32(val, i2c->base + reg);
+}
+
-+static u32 rt_i2c_r32(unsigned reg)
++static u32 mtk_i2c_r32(struct mtk_i2c *i2c, unsigned reg)
+{
-+ return ioread32(membase + reg);
++ return ioread32(i2c->base + reg);
+}
+
-+static void mt7621_i2c_reset(struct i2c_adapter *a)
++static int poll_down_timeout(void __iomem *addr, u32 mask)
+{
-+ device_reset(a->dev.parent);
++ unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
++
++ do {
++ if (!(readl_relaxed(addr) & mask))
++ return 0;
++
++ usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
++ } while (time_before(jiffies, timeout));
++
++ return (readl_relaxed(addr) & mask) ? -EAGAIN : 0;
+}
-+static void mt7621_i2c_enable(struct i2c_msg *msg)
++
++static int mtk_i2c_wait_idle(struct mtk_i2c *i2c)
+{
-+ rt_i2c_w32(msg->addr,REG_DEVADDR_REG);
-+ rt_i2c_w32(0,REG_ADDR_REG);
++ int ret;
++
++ ret = poll_down_timeout(i2c->base + REG_SM0ST, I2C_BUSY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "idle err(%d)\n", ret);
++
++ return ret;
+}
+
-+static void i2c_master_init(struct i2c_adapter *a)
++static int poll_up_timeout(void __iomem *addr, u32 mask)
+{
-+ mt7621_i2c_reset(a);
-+ rt_i2c_w32(I2C_CFG_DEFAULT,REG_CONFIG_REG);
-+ rt_i2c_w32(SM0_CFG_DEFUALT,REG_SM0CTL0);
-+ rt_i2c_w32(1,REG_SM0_IS_AUTOMODE);//auto mode
-+}
++ unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
++ u32 status;
+
++ do {
++ status = readl_relaxed(addr);
++ if (status & mask)
++ return 0;
++ usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
++ } while (time_before(jiffies, timeout));
+
-+static inline int rt_i2c_wait_rx_done(void)
-+{
-+ int i=0;
-+ while((!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY)) && (i<i2c_busy_loop))
-+ i++;
-+ if(i>=i2c_busy_loop){
-+ pr_err("err,wait for idle timeout");
-+ return -ETIMEDOUT;
-+ }
-+ return 0;
++ return -ETIMEDOUT;
+}
+
-+static inline int rt_i2c_wait_idle(void)
++static int mtk_i2c_wait_rx_done(struct mtk_i2c *i2c)
+{
-+ int i=0;
-+ while((rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY) && (i<i2c_busy_loop))
-+ i++;
-+ if(i>=i2c_busy_loop){
-+ pr_err("err,wait for idle timeout");
-+ return -ETIMEDOUT;
-+ }
-+ return 0;
++ int ret;
++
++ ret = poll_up_timeout(i2c->base + REG_SM0ST, I2C_DATARDY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "rx err(%d)\n", ret);
++
++ return ret;
+}
+
-+static inline int rt_i2c_wait_tx_done(void)
++static int mtk_i2c_wait_tx_done(struct mtk_i2c *i2c)
+{
-+ int i=0;
-+ while((!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY)) && (i<i2c_busy_loop))
-+ i++;
-+ if(i>=i2c_busy_loop){
-+ pr_err("err,wait for idle timeout");
-+ return -ETIMEDOUT;
-+ }
-+ return 0;
++ int ret;
++
++ ret = poll_up_timeout(i2c->base + REG_SM0ST, I2C_SDOEMPTY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "tx err(%d)\n", ret);
++
++ return ret;
+}
+
-+static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
++static void mtk_i2c_reset(struct mtk_i2c *i2c)
+{
-+ int i = 0, j = 0, pos = 0;
-+ int nblock = msg->len / READ_BLOCK;
-+ int rem = msg->len % READ_BLOCK;
++ u32 reg;
++ device_reset(i2c->adap.dev.parent);
++ barrier();
+
-+ if (msg->flags & I2C_M_TEN) {
-+ printk("10 bits addr not supported\n");
-+ return -EINVAL;
-+ }
++ /* ctrl0 */
++ reg = ODRAIN_HIGH_SM0 | VSYNC_PULSE | (i2c->clk_div << CLK_DIV_SHIFT) |
++ WAIT_HIGH | SM0_EN;
++ mtk_i2c_w32(i2c, reg, REG_SM0CTL0);
+
-+ if (msg->flags & I2C_M_RD) {
-+ for (i = 0; i < nblock; i++) {
-+ if (rt_i2c_wait_idle())
-+ goto err_timeout;
-+ rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
-+ rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
-+ for (j = 0; j < READ_BLOCK; j++) {
-+ if (rt_i2c_wait_rx_done())
-+ goto err_timeout;
-+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
-+ }
-+ }
++ /* auto mode */
++ mtk_i2c_w32(i2c, AUTOMODE_EN, REG_SM0CFG2);
++}
++
++static void mtk_i2c_dump_reg(struct mtk_i2c *i2c)
++{
++ dev_dbg(i2c->dev, "cfg0 %08x, dout %08x, din %08x, " \
++ "status %08x, auto %08x, cfg1 %08x, " \
++ "cfg2 %08x, ctl0 %08x, ctl1 %08x\n",
++ mtk_i2c_r32(i2c, REG_SM0CFG0),
++ mtk_i2c_r32(i2c, REG_SM0DOUT),
++ mtk_i2c_r32(i2c, REG_SM0DIN),
++ mtk_i2c_r32(i2c, REG_SM0ST),
++ mtk_i2c_r32(i2c, REG_SM0AUTO),
++ mtk_i2c_r32(i2c, REG_SM0CFG1),
++ mtk_i2c_r32(i2c, REG_SM0CFG2),
++ mtk_i2c_r32(i2c, REG_SM0CTL0),
++ mtk_i2c_r32(i2c, REG_SM0CTL1));
++}
+
-+ if (rt_i2c_wait_idle())
-+ goto err_timeout;
-+ rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
-+ rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
-+
-+ for (i = 0; i < rem; i++) {
-+ if (rt_i2c_wait_rx_done())
-+ goto err_timeout;
-+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
++static int mtk_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
++ int num)
++{
++ struct mtk_i2c *i2c;
++ struct i2c_msg *pmsg;
++ int i, j, ret;
++ u32 cmd;
++
++ i2c = i2c_get_adapdata(adap);
++
++ for (i = 0; i < num; i++) {
++ pmsg = &msgs[i];
++ cmd = 0;
++
++ dev_dbg(i2c->dev, "addr: 0x%x, len: %d, flags: 0x%x\n",
++ pmsg->addr, pmsg->len, pmsg->flags);
++
++ /* wait hardware idle */
++ if ((ret = mtk_i2c_wait_idle(i2c)))
++ goto err_timeout;
++
++ if (pmsg->flags & I2C_M_TEN) {
++ dev_dbg(i2c->dev, "10 bits addr not supported\n");
++ return -EINVAL;
++ } else {
++ /* 7 bits address */
++ mtk_i2c_w32(i2c, pmsg->addr & I2C_DEVADDR_MASK,
++ REG_SM0CFG0);
+ }
-+ } else {
-+ if (rt_i2c_wait_idle())
-+ goto err_timeout;
-+ 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);
-+ if(i == 0)
-+ rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
-+
-+ if (rt_i2c_wait_tx_done())
-+ goto err_timeout;
++
++ /* buffer length */
++ if (pmsg->len == 0) {
++ dev_dbg(i2c->dev, "length is 0\n");
++ return -EINVAL;
++ } else
++ mtk_i2c_w32(i2c, SET_BYTECNT(pmsg->len),
++ REG_SM0CFG1);
++
++ j = 0;
++ if (pmsg->flags & I2C_M_RD) {
++ cmd |= READ_CMD;
++ /* start transfer */
++ barrier();
++ mtk_i2c_w32(i2c, cmd, REG_SM0AUTO);
++ do {
++ /* wait */
++ if ((ret = mtk_i2c_wait_rx_done(i2c)))
++ goto err_timeout;
++ /* read data */
++ if (pmsg->len)
++ pmsg->buf[j] = mtk_i2c_r32(i2c,
++ REG_SM0DIN);
++ j++;
++ } while (j < pmsg->len);
++ } else {
++ do {
++ /* write data */
++ if (pmsg->len)
++ mtk_i2c_w32(i2c, pmsg->buf[j],
++ REG_SM0DOUT);
++ /* start transfer */
++ if (j == 0) {
++ barrier();
++ mtk_i2c_w32(i2c, cmd, REG_SM0AUTO);
++ }
++ /* wait */
++ if ((ret = mtk_i2c_wait_tx_done(i2c)))
++ goto err_timeout;
++ j++;
++ } while (j < pmsg->len);
+ }
+ }
++ /* the return value is number of executed messages */
++ ret = i;
+
-+ return 0;
-+err_timeout:
-+ return -ETIMEDOUT;
-+}
++ return ret;
+
-+static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
-+{
-+ int i = 0;
-+ int ret = 0;
-+ i2c_master_init(a);
-+ mt7621_i2c_enable(m);
-+
-+ for (i = 0; i != n && ret==0; i++) {
-+ ret = rt_i2c_handle_msg(a, &m[i]);
-+ if (ret)
-+ return ret;
-+ }
-+ return i;
++err_timeout:
++ mtk_i2c_dump_reg(i2c);
++ mtk_i2c_reset(i2c);
++ return ret;
+}
+
-+static u32 rt_i2c_func(struct i2c_adapter *a)
++static u32 mtk_i2c_func(struct i2c_adapter *a)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
-+static const struct i2c_algorithm rt_i2c_algo = {
-+ .master_xfer = rt_i2c_master_xfer,
-+ .functionality = rt_i2c_func,
++static const struct i2c_algorithm mtk_i2c_algo = {
++ .master_xfer = mtk_i2c_master_xfer,
++ .functionality = mtk_i2c_func,
+};
+
-+static int rt_i2c_probe(struct platform_device *pdev)
++static const struct of_device_id i2c_mtk_dt_ids[] = {
++ { .compatible = "mediatek,mt7621-i2c" },
++ { /* sentinel */ }
++};
++
++MODULE_DEVICE_TABLE(of, i2c_mtk_dt_ids);
++
++static struct i2c_adapter_quirks mtk_i2c_quirks = {
++ .max_write_len = BYTECNT_MAX,
++ .max_read_len = BYTECNT_MAX,
++};
++
++static void mtk_i2c_init(struct mtk_i2c *i2c)
++{
++ i2c->clk_div = clk_get_rate(i2c->clk) / i2c->cur_clk;
++ if (i2c->clk_div > CLK_DIV_MASK)
++ i2c->clk_div = CLK_DIV_MASK;
++
++ mtk_i2c_reset(i2c);
++}
++
++static int mtk_i2c_probe(struct platform_device *pdev)
+{
-+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ struct resource *res;
++ struct mtk_i2c *i2c;
++ struct i2c_adapter *adap;
++ const struct of_device_id *match;
+ int ret;
+
-+ adapter = devm_kzalloc(&pdev->dev,sizeof(struct i2c_adapter), GFP_KERNEL);
-+ if (!adapter) {
++ match = of_match_device(i2c_mtk_dt_ids, &pdev->dev);
++
++ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ if (!res) {
++ dev_err(&pdev->dev, "no memory resource found\n");
++ return -ENODEV;
++ }
++
++ i2c = devm_kzalloc(&pdev->dev, sizeof(struct mtk_i2c), GFP_KERNEL);
++ if (!i2c) {
+ dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
+ return -ENOMEM;
+ }
-+ membase = devm_ioremap_resource(&pdev->dev, res);
-+ if (IS_ERR(membase))
-+ return PTR_ERR(membase);
-+
-+ strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
-+
-+ adapter->owner = THIS_MODULE;
-+ adapter->nr = pdev->id;
-+ adapter->timeout = HZ;
-+ adapter->algo = &rt_i2c_algo;
-+ adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-+ adapter->dev.parent = &pdev->dev;
-+ adapter->dev.of_node = pdev->dev.of_node;
-+
-+ platform_set_drvdata(pdev, adapter);
-+
-+ ret = i2c_add_numbered_adapter(adapter);
-+ if (ret)
++
++ i2c->base = devm_ioremap_resource(&pdev->dev, res);
++ if (IS_ERR(i2c->base))
++ return PTR_ERR(i2c->base);
++
++ i2c->clk = devm_clk_get(&pdev->dev, NULL);
++ if (IS_ERR(i2c->clk)) {
++ dev_err(&pdev->dev, "no clock defined\n");
++ return -ENODEV;
++ }
++ clk_prepare_enable(i2c->clk);
++ i2c->dev = &pdev->dev;
++
++ if (of_property_read_u32(pdev->dev.of_node,
++ "clock-frequency", &i2c->cur_clk))
++ i2c->cur_clk = 100000;
++
++ adap = &i2c->adap;
++ adap->owner = THIS_MODULE;
++ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
++ adap->algo = &mtk_i2c_algo;
++ adap->retries = 3;
++ adap->dev.parent = &pdev->dev;
++ i2c_set_adapdata(adap, i2c);
++ adap->dev.of_node = pdev->dev.of_node;
++ strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
++ adap->quirks = &mtk_i2c_quirks;
++
++ platform_set_drvdata(pdev, i2c);
++
++ mtk_i2c_init(i2c);
++
++ ret = i2c_add_adapter(adap);
++ if (ret < 0) {
++ dev_err(&pdev->dev, "failed to add adapter\n");
++ clk_disable_unprepare(i2c->clk);
+ return ret;
++ }
+
-+ dev_info(&pdev->dev,"loaded");
++ dev_info(&pdev->dev, "clock %uKHz, re-start not support\n",
++ i2c->cur_clk/1000);
+
-+ return 0;
++ return ret;
+}
+
-+static int rt_i2c_remove(struct platform_device *pdev)
++static int mtk_i2c_remove(struct platform_device *pdev)
+{
-+ platform_set_drvdata(pdev, NULL);
-+ return 0;
-+}
++ struct mtk_i2c *i2c = platform_get_drvdata(pdev);
+
-+static const struct of_device_id i2c_rt_dt_ids[] = {
-+ { .compatible = "ralink,i2c-mt7621", },
-+ { /* sentinel */ }
-+};
++ i2c_del_adapter(&i2c->adap);
++ clk_disable_unprepare(i2c->clk);
+
-+MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
++ return 0;
++}
+
-+static struct platform_driver rt_i2c_driver = {
-+ .probe = rt_i2c_probe,
-+ .remove = rt_i2c_remove,
++static struct platform_driver mtk_i2c_driver = {
++ .probe = mtk_i2c_probe,
++ .remove = mtk_i2c_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "i2c-mt7621",
-+ .of_match_table = i2c_rt_dt_ids,
++ .of_match_table = i2c_mtk_dt_ids,
+ },
+};
+
-+static int __init i2c_rt_init (void)
++static int __init i2c_mtk_init (void)
+{
-+ return platform_driver_register(&rt_i2c_driver);
++ return platform_driver_register(&mtk_i2c_driver);
+}
++subsys_initcall(i2c_mtk_init);
+
-+static void __exit i2c_rt_exit (void)
++static void __exit i2c_mtk_exit (void)
+{
-+ platform_driver_unregister(&rt_i2c_driver);
++ platform_driver_unregister(&mtk_i2c_driver);
+}
-+module_init (i2c_rt_init);
-+module_exit (i2c_rt_exit);
++module_exit(i2c_mtk_exit);
+
+MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
+MODULE_DESCRIPTION("MT7621 I2c host driver");