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path: root/drivers/i2c/busses/i2c-rcar.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c65
1 files changed, 44 insertions, 21 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index d2fe11da5e82..2c2fd7c2b116 100644
--- 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,