diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 65 |
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, |