Re: [PATCH 3/3] i2c: nomadik: Add Device Tree support to the Nomadik I2C driver

[Lee Jones <lee.jones@linaro.org>]

Author: Lee Jones <lee.jones@linaro.org>
Date:   Mon Aug 6 11:09:57 2012 +0100

    i2c: nomadik: Add Device Tree support to the Nomadik I2C driver
    
    Here we apply the bindings required for successful Device Tree
    probing of the i2c-nomadik driver.
    
    Cc: linux-i2c@vger.kernel.org
    Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 61b00ed..5d1a970 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -25,6 +25,7 @@
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
 #include <linux/platform_data/i2c-nomadik.h>
+#include <linux/of.h>
 
 #define DRIVER_NAME "nmk-i2c"
 
@@ -920,18 +921,42 @@ static struct nmk_i2c_controller u8500_i2c = {
        .sm             = I2C_FREQ_MODE_FAST,
 };
 
+static void nmk_i2c_of_probe(struct device_node *np,
+                       struct nmk_i2c_controller *pdata)
+{
+       of_property_read_u32(np, "clock-frequency", &pdata->clk_freq);
+
+       /* This driver only supports 'standard' and 'fast' modes of operation. */
+       if (pdata->clk_freq <= 100000)
+               pdata->sm = I2C_FREQ_MODE_STANDARD;
+       else
+               pdata->sm = I2C_FREQ_MODE_FAST;
+}
+
 static atomic_t adapter_id = ATOMIC_INIT(0);
 
 static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
 {
        int ret = 0;
        struct nmk_i2c_controller *pdata = adev->dev.platform_data;
+       struct device_node *np = adev->dev.of_node;
        struct nmk_i2c_dev      *dev;
        struct i2c_adapter *adap;
 
-       if (!pdata)
-               /* No i2c configuration found, using the default. */
-               pdata = &u8500_i2c;
+       if (!pdata) {
+               if (np) {
+                       pdata = devm_kzalloc(&adev->dev, sizeof(*pdata), GFP_KERNEL);
+                       if (!pdata) {
+                               ret = -ENOMEM;
+                               goto err_no_mem;
+                       }
+                       /* Provide the default configuration as a base. */
+                       memcpy(pdata, &u8500_i2c, sizeof(struct nmk_i2c_controller));
+                       nmk_i2c_of_probe(np, pdata);
+               } else
+                       /* No i2c configuration found, using the default. */
+                       pdata = &u8500_i2c;
+       }
 
        dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
        if (!dev) {
diff --git a/include/linux/platform_data/i2c-nomadik.h b/include/linux/platform_data/i2c-nomadik.h
index c2303c3..3a8be9c 100644
--- a/include/linux/platform_data/i2c-nomadik.h
+++ b/include/linux/platform_data/i2c-nomadik.h
@@ -28,7 +28,7 @@ enum i2c_freq_mode {
  * @sm:                speed mode
  */
 struct nmk_i2c_controller {
-       unsigned long   clk_freq;
+       u32             clk_freq;
        unsigned short  slsu;
        unsigned char   tft;
        unsigned char   rft;