media: i2c: ov5670: Use common clock framework

Add support for probing the main system clock using the common clock
framework and its OF bindings.

Maintain ACPI compatibility by falling back to parse 'clock-frequency'.

Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Tested-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
index 07a396c..52b799a 100644 (file)
--- a/drivers/media/i2c/ov5670.c
+++ b/drivers/media/i2c/ov5670.c
@@ -2,6 +2,7 @@
 // Copyright (c) 2017 Intel Corporation.
 
 #include <linux/acpi.h>
+#include <linux/clk.h>
 #include <linux/i2c.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
@@ -12,6 +13,8 @@
 #include <media/v4l2-event.h>
 #include <media/v4l2-fwnode.h>
 
+#define OV5670_XVCLK_FREQ              19200000
+
 #define OV5670_REG_CHIP_ID             0x300a
 #define OV5670_CHIP_ID                 0x005670
 
@@ -1830,6 +1833,9 @@ struct ov5670 {
        /* Current mode */
        const struct ov5670_mode *cur_mode;
 
+       /* xvclk input clock */
+       struct clk *xvclk;
+
        /* To serialize asynchronus callbacks */
        struct mutex mutex;
 
@@ -2478,10 +2484,6 @@ static int ov5670_probe(struct i2c_client *client)
        bool full_power;
        int ret;
 
-       device_property_read_u32(&client->dev, "clock-frequency", &input_clk);
-       if (input_clk != 19200000)
-               return -EINVAL;
-
        ov5670 = devm_kzalloc(&client->dev, sizeof(*ov5670), GFP_KERNEL);
        if (!ov5670) {
                ret = -ENOMEM;
@@ -2489,6 +2491,22 @@ static int ov5670_probe(struct i2c_client *client)
                goto error_print;
        }
 
+       ov5670->xvclk = devm_clk_get(&client->dev, NULL);
+       if (!IS_ERR_OR_NULL(ov5670->xvclk))
+               input_clk = clk_get_rate(ov5670->xvclk);
+       else if (PTR_ERR(ov5670->xvclk) == -ENOENT)
+               device_property_read_u32(&client->dev, "clock-frequency",
+                                        &input_clk);
+       else
+               return dev_err_probe(&client->dev, PTR_ERR(ov5670->xvclk),
+                                    "error getting clock\n");
+
+       if (input_clk != OV5670_XVCLK_FREQ) {
+               dev_err(&client->dev,
+                       "Unsupported clock frequency %u\n", input_clk);
+               return -EINVAL;
+       }
+
        /* Initialize subdev */
        v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops);