Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck...

[linux-drm-fsl-dcu.git] / drivers / i2c / busses / i2c-rcar.c

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index d2fe11da5e82a43cdc80c9fc9446aeb1e7c7fa0b..2c2fd7c2b116624f737352fb6ea5dee55ff3cad3 100644 (file)
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -33,6 +33,7 @@
 #include <linux/i2c/i2c-rcar.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
@@ -102,8 +103,8 @@ enum {
 #define ID_NACK                (1 << 4)
 
 enum rcar_i2c_type {
-       I2C_RCAR_H1,
-       I2C_RCAR_H2,
+       I2C_RCAR_GEN1,
+       I2C_RCAR_GEN2,
 };
 
 struct rcar_i2c_priv {
@@ -226,22 +227,23 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
                                    u32 bus_speed,
                                    struct device *dev)
 {
-       struct clk *clkp = clk_get(NULL, "peripheral_clk");
+       struct clk *clkp = clk_get(dev, NULL);
        u32 scgd, cdf;
        u32 round, ick;
        u32 scl;
        u32 cdf_width;
+       unsigned long rate;
 
-       if (!clkp) {
-               dev_err(dev, "there is no peripheral_clk\n");
-               return -EIO;
+       if (IS_ERR(clkp)) {
+               dev_err(dev, "couldn't get clock\n");
+               return PTR_ERR(clkp);
        }
 
        switch (priv->devtype) {
-       case I2C_RCAR_H1:
+       case I2C_RCAR_GEN1:
                cdf_width = 2;
                break;
-       case I2C_RCAR_H2:
+       case I2C_RCAR_GEN2:
                cdf_width = 3;
                break;
        default:
@@ -264,15 +266,14 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
         * clkp : peripheral_clk
         * F[]  : integer up-valuation
         */
-       for (cdf = 0; cdf < (1 << cdf_width); cdf++) {
-               ick = clk_get_rate(clkp) / (1 + cdf);
-               if (ick < 20000000)
-                       goto ick_find;
+       rate = clk_get_rate(clkp);
+       cdf = rate / 20000000;
+       if (cdf >= 1 << cdf_width) {
+               dev_err(dev, "Input clock %lu too high\n", rate);
+               return -EIO;
        }
-       dev_err(dev, "there is no best CDF\n");
-       return -EIO;
+       ick = rate / (cdf + 1);
 
-ick_find:
        /*
         * it is impossible to calculate large scale
         * number on u32. separate it
@@ -290,6 +291,12 @@ ick_find:
         *
         * Calculation result (= SCL) should be less than
         * bus_speed for hardware safety
+        *
+        * We could use something along the lines of
+        *      div = ick / (bus_speed + 1) + 1;
+        *      scgd = (div - 20 - round + 7) / 8;
+        *      scl = ick / (20 + (scgd * 8) + round);
+        * (not fully verified) but that would get pretty involved
         */
        for (scgd = 0; scgd < 0x40; scgd++) {
                scl = ick / (20 + (scgd * 8) + round);
@@ -306,7 +313,7 @@ scgd_find:
        /*
         * keep icccr value
         */
-       priv->icccr = (scgd << (cdf_width) | cdf);
+       priv->icccr = scgd << cdf_width | cdf;
 
        return 0;
 }
@@ -632,6 +639,15 @@ static const struct i2c_algorithm rcar_i2c_algo = {
        .functionality  = rcar_i2c_func,
 };
 
+static const struct of_device_id rcar_i2c_dt_ids[] = {
+       { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 },
+       { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
+       { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
+       { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
+       {},
+};
+MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
+
 static int rcar_i2c_probe(struct platform_device *pdev)
 {
        struct i2c_rcar_platform_data *pdata = dev_get_platdata(&pdev->dev);
@@ -649,10 +665,15 @@ static int rcar_i2c_probe(struct platform_device *pdev)
        }
 
        bus_speed = 100000; /* default 100 kHz */
-       if (pdata && pdata->bus_speed)
+       ret = of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed);
+       if (ret < 0 && pdata && pdata->bus_speed)
                bus_speed = pdata->bus_speed;
 
-       priv->devtype = platform_get_device_id(pdev)->driver_data;
+       if (pdev->dev.of_node)
+               priv->devtype = (long)of_match_device(rcar_i2c_dt_ids,
+                                                     dev)->data;
+       else
+               priv->devtype = platform_get_device_id(pdev)->driver_data;
 
        ret = rcar_i2c_clock_calculate(priv, bus_speed, dev);
        if (ret < 0)
@@ -673,6 +694,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
        adap->class             = I2C_CLASS_HWMON | I2C_CLASS_SPD;
        adap->retries           = 3;
        adap->dev.parent        = dev;
+       adap->dev.of_node       = dev->of_node;
        i2c_set_adapdata(adap, priv);
        strlcpy(adap->name, pdev->name, sizeof(adap->name));
 
@@ -709,9 +731,9 @@ static int rcar_i2c_remove(struct platform_device *pdev)
 }
 
 static struct platform_device_id rcar_i2c_id_table[] = {
-       { "i2c-rcar",           I2C_RCAR_H1 },
-       { "i2c-rcar_h1",        I2C_RCAR_H1 },
-       { "i2c-rcar_h2",        I2C_RCAR_H2 },
+       { "i2c-rcar",           I2C_RCAR_GEN1 },
+       { "i2c-rcar_gen1",      I2C_RCAR_GEN1 },
+       { "i2c-rcar_gen2",      I2C_RCAR_GEN2 },
        {},
 };
 MODULE_DEVICE_TABLE(platform, rcar_i2c_id_table);
@@ -720,6 +742,7 @@ static struct platform_driver rcar_i2c_driver = {
        .driver = {
                .name   = "i2c-rcar",
                .owner  = THIS_MODULE,
+               .of_match_table = rcar_i2c_dt_ids,
        },
        .probe          = rcar_i2c_probe,
        .remove         = rcar_i2c_remove,