media: mt9m114: Add support for ACPI clock-frequency property

Add support for ACPI-based platforms that specify the clock frequency by
using the "clock-frequency" property.

On ACPI platforms the clock is turned on/off through ACPI power-resources
depending on the runtime-pm state, so there is no clock provider reference.

Signed-off-by: Hans de Goede <[email protected]>

drivers/media/i2c/mt9m114.c

@@ -377,6 +377,7 @@ struct mt9m114 {
 	struct gpio_desc *reset;
 	struct regulator_bulk_data supplies[3];
 	struct v4l2_fwnode_endpoint bus_cfg;
+	u32 clk_freq;
 
 	struct {
 		unsigned int m;
@@ -2122,14 +2123,13 @@ static int mt9m114_power_on(struct mt9m114 *sensor)
 
 	/* Perform a hard reset if available, or a soft reset otherwise. */
 	if (sensor->reset) {
-		long freq = clk_get_rate(sensor->clk);
 		unsigned int duration;
 
 		/*
 		 * The minimum duration is 50 clock cycles, thus typically
 		 * around 2µs. Double it to be safe.
 		 */
-		duration = DIV_ROUND_UP(2 * 50 * 1000000, freq);
+		duration = DIV_ROUND_UP(2 * 50 * 1000000, sensor->clk_freq);
 
 		gpiod_set_value(sensor->reset, 1);
 		fsleep(duration);
@@ -2249,7 +2249,7 @@ static int mt9m114_clk_init(struct mt9m114 *sensor)
 	 * for 16-bit per pixel, transmitted in DDR over a single lane. For
 	 * parallel mode, the sensor ouputs one pixel in two PIXCLK cycles.
 	 */
-	sensor->pixrate = clk_get_rate(sensor->clk) * sensor->pll.m
+	sensor->pixrate = sensor->clk_freq * sensor->pll.m
 			/ ((sensor->pll.n + 1) * (sensor->pll.p + 1));
 
 	link_freq = sensor->bus_cfg.bus_type == V4L2_MBUS_CSI2_DPHY
@@ -2360,13 +2360,25 @@ static int mt9m114_probe(struct i2c_client *client)
 		return ret;
 
 	/* Acquire clocks, GPIOs and regulators. */
-	sensor->clk = devm_clk_get(dev, NULL);
+	sensor->clk = devm_clk_get_optional(dev, NULL);
 	if (IS_ERR(sensor->clk)) {
 		ret = PTR_ERR(sensor->clk);
 		dev_err_probe(dev, ret, "Failed to get clock\n");
 		goto error_ep_free;
 	}
 
+	if (sensor->clk) {
+		sensor->clk_freq = clk_get_rate(sensor->clk);
+	} else {
+		ret = fwnode_property_read_u32(dev_fwnode(dev),
+					       "clock-frequency",
+					       &sensor->clk_freq);
+		if (ret) {
+			dev_err_probe(dev, ret, "Failed to read clock-freq\n");
+			goto error_ep_free;
+		}
+	}
+
 	sensor->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(sensor->reset)) {
 		ret = PTR_ERR(sensor->reset);