[PATCH v4 04/45] media: sun6i-csi: Always set exclusive module clock rate

[Paul Kocialkowski]

In some situations the default rate of the module clock is not the
required one for operation (for example when reconfiguring the clock
tree to use a different parent). As a result, always set the correct
rate for the clock (and take care of cleanup).

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
Reviewed-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
---
 .../platform/sunxi/sun6i-csi/sun6i_csi.c      | 54 ++++++++++++++-----
 1 file changed, 41 insertions(+), 13 deletions(-)

diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
index becd8d17f8eb..827583a30ad0 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c
@@ -154,9 +154,6 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
 		regmap_update_bits(regmap, CSI_EN_REG, CSI_EN_CSI_EN, 0);
 
 		clk_disable_unprepare(csi_dev->clock_ram);
-		if (of_device_is_compatible(dev->of_node,
-					    "allwinner,sun50i-a64-csi"))
-			clk_rate_exclusive_put(csi_dev->clock_mod);
 		clk_disable_unprepare(csi_dev->clock_mod);
 		reset_control_assert(csi_dev->reset);
 		return 0;
@@ -168,9 +165,6 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
 		return ret;
 	}
 
-	if (of_device_is_compatible(dev->of_node, "allwinner,sun50i-a64-csi"))
-		clk_set_rate_exclusive(csi_dev->clock_mod, 300000000);
-
 	ret = clk_prepare_enable(csi_dev->clock_ram);
 	if (ret) {
 		dev_err(csi_dev->dev, "Enable clk_dram_csi clk err %d\n", ret);
@@ -190,8 +184,6 @@ int sun6i_csi_set_power(struct sun6i_csi_device *csi_dev, bool enable)
 clk_ram_disable:
 	clk_disable_unprepare(csi_dev->clock_ram);
 clk_mod_disable:
-	if (of_device_is_compatible(dev->of_node, "allwinner,sun50i-a64-csi"))
-		clk_rate_exclusive_put(csi_dev->clock_mod);
 	clk_disable_unprepare(csi_dev->clock_mod);
 	return ret;
 }
@@ -819,6 +811,7 @@ static int sun6i_csi_resources_setup(struct sun6i_csi_device *csi_dev,
 				     struct platform_device *platform_dev)
 {
 	struct device *dev = csi_dev->dev;
+	unsigned long clock_mod_rate;
 	void __iomem *io_base;
 	int ret;
 	int irq;
@@ -850,28 +843,53 @@ static int sun6i_csi_resources_setup(struct sun6i_csi_device *csi_dev,
 		return PTR_ERR(csi_dev->clock_ram);
 	}
 
+	if (of_device_is_compatible(dev->of_node, "allwinner,sun50i-a64-csi"))
+		clock_mod_rate = 300000000;
+	else
+		clock_mod_rate = 297000000;
+
+	ret = clk_set_rate_exclusive(csi_dev->clock_mod, clock_mod_rate);
+	if (ret) {
+		dev_err(dev, "failed to set mod clock rate\n");
+		return ret;
+	}
+
 	/* Reset */
 
 	csi_dev->reset = devm_reset_control_get_shared(dev, NULL);
 	if (IS_ERR(csi_dev->reset)) {
 		dev_err(dev, "failed to acquire reset\n");
-		return PTR_ERR(csi_dev->reset);
+		ret = PTR_ERR(csi_dev->reset);
+		goto error_clock_rate_exclusive;
 	}
 
 	/* Interrupt */
 
 	irq = platform_get_irq(platform_dev, 0);
-	if (irq < 0)
-		return -ENXIO;
+	if (irq < 0) {
+		dev_err(dev, "failed to get interrupt\n");
+		ret = -ENXIO;
+		goto error_clock_rate_exclusive;
+	}
 
 	ret = devm_request_irq(dev, irq, sun6i_csi_interrupt, 0, SUN6I_CSI_NAME,
 			       csi_dev);
 	if (ret) {
 		dev_err(dev, "failed to request interrupt\n");
-		return ret;
+		goto error_clock_rate_exclusive;
 	}
 
 	return 0;
+
+error_clock_rate_exclusive:
+	clk_rate_exclusive_put(csi_dev->clock_mod);
+
+	return ret;
+}
+
+static void sun6i_csi_resources_cleanup(struct sun6i_csi_device *csi_dev)
+{
+	clk_rate_exclusive_put(csi_dev->clock_mod);
 }
 
 static int sun6i_csi_probe(struct platform_device *platform_dev)
@@ -891,7 +909,16 @@ static int sun6i_csi_probe(struct platform_device *platform_dev)
 	if (ret)
 		return ret;
 
-	return sun6i_csi_v4l2_init(csi_dev);
+	ret = sun6i_csi_v4l2_init(csi_dev);
+	if (ret)
+		goto error_resources;
+
+	return 0;
+
+error_resources:
+	sun6i_csi_resources_cleanup(csi_dev);
+
+	return ret;
 }
 
 static int sun6i_csi_remove(struct platform_device *pdev)
@@ -899,6 +926,7 @@ static int sun6i_csi_remove(struct platform_device *pdev)
 	struct sun6i_csi_device *csi_dev = platform_get_drvdata(pdev);
 
 	sun6i_csi_v4l2_cleanup(csi_dev);
+	sun6i_csi_resources_cleanup(csi_dev);
 
 	return 0;
 }
-- 
2.35.2