[PATCH 0/6] media: staging: media: imx6-mipi-csi2: trivial cleanup to prepare convert to common dw mipi csi2

[PATCH 0/6] media: staging: media: imx6-mipi-csi2: trivial cleanup to prepare convert to common dw mipi csi2

[Frank Li]

Previous https://lore.kernel.org/imx/20250821-95_cam-v3-0-c9286fbb34b9@nxp.com/
There are too much patches (32) in above thread.

Just extract first 6 cleanup patches to review easily. The overall road
map see above 32 patch serise.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Frank Li (6):
      media: staging: media: imx6-mipi-csi2: replace space with tab for alignment
      media: staging: media: imx6-mipi-csi2: use devm_add_action_or_reset() to simplify code
      media: staging: media: imx6-mipi-csi2: use devm_clk_bulk_get_all() to fetch clocks
      media: staging: media: imx6-mipi-csi2: use devm_mutex_init() to simplify code
      media: staging: media: imx6-mipi-csi2: use guard() to simplify code
      media: staging: media: imx6-mipi-csi2: use devm_platform_ioremap_resource() simplify code

 drivers/staging/media/imx/imx6-mipi-csi2.c | 234 +++++++++++------------------
 1 file changed, 89 insertions(+), 145 deletions(-)
---
base-commit: df5d79720b152e7ff058f11ed7e88d5b5c8d2a0c
change-id: 20251106-stage-csi2-cleanup-6db1715fd187

Best regards,
--
Frank Li <Frank.Li@nxp.com>

[PATCH 1/6] media: staging: media: imx6-mipi-csi2: replace space with tab for alignment

[Frank Li]

Replace space with tab to follow coding convention. No functional change.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 92 +++++++++++++++---------------
 1 file changed, 46 insertions(+), 46 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index dd8c7b3233bccfc34b59e0f0ff813b36752e1526..42256441b881d9f132ad7ff899d6f1e35643b4ac 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -23,65 +23,65 @@
  * there must be 5 pads: 1 input pad from sensor, and
  * the 4 virtual channel output pads
  */
-#define CSI2_SINK_PAD       0
-#define CSI2_NUM_SINK_PADS  1
-#define CSI2_NUM_SRC_PADS   4
-#define CSI2_NUM_PADS       5
+#define CSI2_SINK_PAD		0
+#define CSI2_NUM_SINK_PADS	1
+#define CSI2_NUM_SRC_PADS	4
+#define CSI2_NUM_PADS		5
 
 /*
  * The default maximum bit-rate per lane in Mbps, if the
  * source subdev does not provide V4L2_CID_LINK_FREQ.
  */
-#define CSI2_DEFAULT_MAX_MBPS 849
+#define CSI2_DEFAULT_MAX_MBPS	849
 
 struct csi2_dev {
-	struct device          *dev;
-	struct v4l2_subdev      sd;
-	struct v4l2_async_notifier notifier;
-	struct media_pad       pad[CSI2_NUM_PADS];
-	struct clk             *dphy_clk;
-	struct clk             *pllref_clk;
-	struct clk             *pix_clk; /* what is this? */
-	void __iomem           *base;
-
-	struct v4l2_subdev	*remote;
-	unsigned int		remote_pad;
-	unsigned short		data_lanes;
+	struct device			*dev;
+	struct v4l2_subdev		sd;
+	struct v4l2_async_notifier	notifier;
+	struct media_pad		pad[CSI2_NUM_PADS];
+	struct clk			*dphy_clk;
+	struct clk			*pllref_clk;
+	struct clk			*pix_clk; /* what is this? */
+	void __iomem			*base;
+
+	struct v4l2_subdev		*remote;
+	unsigned int			remote_pad;
+	unsigned short			data_lanes;
 
 	/* lock to protect all members below */
-	struct mutex lock;
+	struct mutex			lock;
 
-	struct v4l2_mbus_framefmt format_mbus;
+	struct v4l2_mbus_framefmt	format_mbus;
 
-	int                     stream_count;
-	struct v4l2_subdev      *src_sd;
-	bool                    sink_linked[CSI2_NUM_SRC_PADS];
+	int				stream_count;
+	struct v4l2_subdev		*src_sd;
+	bool				sink_linked[CSI2_NUM_SRC_PADS];
 };
 
 #define DEVICE_NAME "imx6-mipi-csi2"
 
 /* Register offsets */
-#define CSI2_VERSION            0x000
-#define CSI2_N_LANES            0x004
-#define CSI2_PHY_SHUTDOWNZ      0x008
-#define CSI2_DPHY_RSTZ          0x00c
-#define CSI2_RESETN             0x010
-#define CSI2_PHY_STATE          0x014
-#define PHY_STOPSTATEDATA_BIT   4
-#define PHY_STOPSTATEDATA(n)    BIT(PHY_STOPSTATEDATA_BIT + (n))
-#define PHY_RXCLKACTIVEHS       BIT(8)
-#define PHY_RXULPSCLKNOT        BIT(9)
-#define PHY_STOPSTATECLK        BIT(10)
-#define CSI2_DATA_IDS_1         0x018
-#define CSI2_DATA_IDS_2         0x01c
-#define CSI2_ERR1               0x020
-#define CSI2_ERR2               0x024
-#define CSI2_MSK1               0x028
-#define CSI2_MSK2               0x02c
-#define CSI2_PHY_TST_CTRL0      0x030
+#define CSI2_VERSION		0x000
+#define CSI2_N_LANES		0x004
+#define CSI2_PHY_SHUTDOWNZ	0x008
+#define CSI2_DPHY_RSTZ		0x00c
+#define CSI2_RESETN		0x010
+#define CSI2_PHY_STATE		0x014
+#define PHY_STOPSTATEDATA_BIT	4
+#define PHY_STOPSTATEDATA(n)	BIT(PHY_STOPSTATEDATA_BIT + (n))
+#define PHY_RXCLKACTIVEHS	BIT(8)
+#define PHY_RXULPSCLKNOT	BIT(9)
+#define PHY_STOPSTATECLK	BIT(10)
+#define CSI2_DATA_IDS_1		0x018
+#define CSI2_DATA_IDS_2		0x01c
+#define CSI2_ERR1		0x020
+#define CSI2_ERR2		0x024
+#define CSI2_MSK1		0x028
+#define CSI2_MSK2		0x02c
+#define CSI2_PHY_TST_CTRL0	0x030
 #define PHY_TESTCLR		BIT(0)
 #define PHY_TESTCLK		BIT(1)
-#define CSI2_PHY_TST_CTRL1      0x034
+#define CSI2_PHY_TST_CTRL1	0x034
 #define PHY_TESTEN		BIT(16)
 /*
  * i.MX CSI2IPU Gasket registers follow. The CSI2IPU gasket is
@@ -106,13 +106,13 @@ static inline struct csi2_dev *notifier_to_dev(struct v4l2_async_notifier *n)
  * reference manual is as follows:
  *
  * 1. Deassert presetn signal (global reset).
- *        It's not clear what this "global reset" signal is (maybe APB
- *        global reset), but in any case this step would be probably
- *        be carried out during driver load in csi2_probe().
+ *	It's not clear what this "global reset" signal is (maybe APB
+ *	global reset), but in any case this step would be probably
+ *	be carried out during driver load in csi2_probe().
  *
  * 2. Configure MIPI Camera Sensor to put all Tx lanes in LP-11 state.
- *        This must be carried out by the MIPI sensor's s_power(ON) subdev
- *        op.
+ *	This must be carried out by the MIPI sensor's s_power(ON) subdev
+ *	op.
  *
  * 3. D-PHY initialization.
  * 4. CSI2 Controller programming (Set N_LANES, deassert PHY_SHUTDOWNZ,

-- 
2.34.1

[PATCH 2/6] media: staging: media: imx6-mipi-csi2: use devm_add_action_or_reset() to simplify code

[Frank Li]

Use devm_add_action_or_reset() to simplify the code. No functional change.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index 42256441b881d9f132ad7ff899d6f1e35643b4ac..eba9a650030f5e380aa900b94728ad375171c6a5 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -716,6 +716,14 @@ static int csi2_async_register(struct csi2_dev *csi2)
 	return ret;
 }
 
+static void csi2_nf_cleanup(void *data)
+{
+	struct csi2_dev *csi2 = data;
+
+	v4l2_async_nf_unregister(&csi2->notifier);
+	v4l2_async_nf_cleanup(&csi2->notifier);
+}
+
 static int csi2_probe(struct platform_device *pdev)
 {
 	struct csi2_dev *csi2;
@@ -749,6 +757,10 @@ static int csi2_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = devm_add_action_or_reset(&pdev->dev, csi2_nf_cleanup, csi2);
+	if (ret)
+		return ret;
+
 	csi2->pllref_clk = devm_clk_get(&pdev->dev, "ref");
 	if (IS_ERR(csi2->pllref_clk)) {
 		v4l2_err(&csi2->sd, "failed to get pll reference clock\n");
@@ -800,8 +812,6 @@ static int csi2_probe(struct platform_device *pdev)
 	return 0;
 
 clean_notifier:
-	v4l2_async_nf_unregister(&csi2->notifier);
-	v4l2_async_nf_cleanup(&csi2->notifier);
 	clk_disable_unprepare(csi2->dphy_clk);
 pllref_off:
 	clk_disable_unprepare(csi2->pllref_clk);
@@ -815,8 +825,6 @@ static void csi2_remove(struct platform_device *pdev)
 	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
 	struct csi2_dev *csi2 = sd_to_dev(sd);
 
-	v4l2_async_nf_unregister(&csi2->notifier);
-	v4l2_async_nf_cleanup(&csi2->notifier);
 	v4l2_async_unregister_subdev(sd);
 	clk_disable_unprepare(csi2->dphy_clk);
 	clk_disable_unprepare(csi2->pllref_clk);

-- 
2.34.1

[PATCH 3/6] media: staging: media: imx6-mipi-csi2: use devm_clk_bulk_get_all() to fetch clocks

[Frank Li]

Use devm_clk_bulk_get_all_enabled() helper to simplify clock handling.

Defer all clock prepare and enable to csi2_start(), which previous only
enable pix clock here.

Do that safely because there are not register access before csi2_start().

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 52 ++++++------------------------
 1 file changed, 9 insertions(+), 43 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index eba9a650030f5e380aa900b94728ad375171c6a5..32ddcef7ec8535a44e121754bb621c0d2e226369 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -39,11 +39,11 @@ struct csi2_dev {
 	struct v4l2_subdev		sd;
 	struct v4l2_async_notifier	notifier;
 	struct media_pad		pad[CSI2_NUM_PADS];
-	struct clk			*dphy_clk;
-	struct clk			*pllref_clk;
-	struct clk			*pix_clk; /* what is this? */
 	void __iomem			*base;
 
+	struct clk_bulk_data		*clks;
+	int				num_clks;
+
 	struct v4l2_subdev		*remote;
 	unsigned int			remote_pad;
 	unsigned short			data_lanes;
@@ -343,7 +343,7 @@ static int csi2_start(struct csi2_dev *csi2)
 	unsigned int lanes;
 	int ret;
 
-	ret = clk_prepare_enable(csi2->pix_clk);
+	ret = clk_bulk_prepare_enable(csi2->num_clks, csi2->clks);
 	if (ret)
 		return ret;
 
@@ -390,7 +390,7 @@ static int csi2_start(struct csi2_dev *csi2)
 err_assert_reset:
 	csi2_enable(csi2, false);
 err_disable_clk:
-	clk_disable_unprepare(csi2->pix_clk);
+	clk_bulk_disable_unprepare(csi2->num_clks, csi2->clks);
 	return ret;
 }
 
@@ -401,7 +401,7 @@ static void csi2_stop(struct csi2_dev *csi2)
 	v4l2_subdev_call(csi2->src_sd, video, post_streamoff);
 
 	csi2_enable(csi2, false);
-	clk_disable_unprepare(csi2->pix_clk);
+	clk_bulk_disable_unprepare(csi2->num_clks, csi2->clks);
 }
 
 /*
@@ -761,24 +761,6 @@ static int csi2_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	csi2->pllref_clk = devm_clk_get(&pdev->dev, "ref");
-	if (IS_ERR(csi2->pllref_clk)) {
-		v4l2_err(&csi2->sd, "failed to get pll reference clock\n");
-		return PTR_ERR(csi2->pllref_clk);
-	}
-
-	csi2->dphy_clk = devm_clk_get(&pdev->dev, "dphy");
-	if (IS_ERR(csi2->dphy_clk)) {
-		v4l2_err(&csi2->sd, "failed to get dphy clock\n");
-		return PTR_ERR(csi2->dphy_clk);
-	}
-
-	csi2->pix_clk = devm_clk_get(&pdev->dev, "pix");
-	if (IS_ERR(csi2->pix_clk)) {
-		v4l2_err(&csi2->sd, "failed to get pixel clock\n");
-		return PTR_ERR(csi2->pix_clk);
-	}
-
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		v4l2_err(&csi2->sd, "failed to get platform resources\n");
@@ -791,19 +773,9 @@ static int csi2_probe(struct platform_device *pdev)
 
 	mutex_init(&csi2->lock);
 
-	ret = clk_prepare_enable(csi2->pllref_clk);
-	if (ret) {
-		v4l2_err(&csi2->sd, "failed to enable pllref_clk\n");
-		goto rmmutex;
-	}
-
-	ret = clk_prepare_enable(csi2->dphy_clk);
-	if (ret) {
-		v4l2_err(&csi2->sd, "failed to enable dphy_clk\n");
-		goto pllref_off;
-	}
-
-	platform_set_drvdata(pdev, &csi2->sd);
+	csi2->num_clks = devm_clk_bulk_get_all(&pdev->dev, &csi2->clks);
+	if (csi2->num_clks < 0)
+		return dev_err_probe(&pdev->dev, csi2->num_clks, "Failed to get clocks\n");
 
 	ret = csi2_async_register(csi2);
 	if (ret)
@@ -812,10 +784,6 @@ static int csi2_probe(struct platform_device *pdev)
 	return 0;
 
 clean_notifier:
-	clk_disable_unprepare(csi2->dphy_clk);
-pllref_off:
-	clk_disable_unprepare(csi2->pllref_clk);
-rmmutex:
 	mutex_destroy(&csi2->lock);
 	return ret;
 }
@@ -826,8 +794,6 @@ static void csi2_remove(struct platform_device *pdev)
 	struct csi2_dev *csi2 = sd_to_dev(sd);
 
 	v4l2_async_unregister_subdev(sd);
-	clk_disable_unprepare(csi2->dphy_clk);
-	clk_disable_unprepare(csi2->pllref_clk);
 	mutex_destroy(&csi2->lock);
 	media_entity_cleanup(&sd->entity);
 }

-- 
2.34.1

[PATCH 4/6] media: staging: media: imx6-mipi-csi2: use devm_mutex_init() to simplify code

[Frank Li]

Use devm_mutex_init() to simplify the code. No functional change.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index 32ddcef7ec8535a44e121754bb621c0d2e226369..f8d0b3b8b250774af51f2aba731e639131aceff9 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -771,30 +771,23 @@ static int csi2_probe(struct platform_device *pdev)
 	if (!csi2->base)
 		return -ENOMEM;
 
-	mutex_init(&csi2->lock);
+	ret = devm_mutex_init(&pdev->dev, &csi2->lock);
+	if (ret)
+		return ret;
 
 	csi2->num_clks = devm_clk_bulk_get_all(&pdev->dev, &csi2->clks);
 	if (csi2->num_clks < 0)
 		return dev_err_probe(&pdev->dev, csi2->num_clks, "Failed to get clocks\n");
 
-	ret = csi2_async_register(csi2);
-	if (ret)
-		goto clean_notifier;
+	return csi2_async_register(csi2);
 
-	return 0;
-
-clean_notifier:
-	mutex_destroy(&csi2->lock);
-	return ret;
 }
 
 static void csi2_remove(struct platform_device *pdev)
 {
 	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
-	struct csi2_dev *csi2 = sd_to_dev(sd);
 
 	v4l2_async_unregister_subdev(sd);
-	mutex_destroy(&csi2->lock);
 	media_entity_cleanup(&sd->entity);
 }
 

-- 
2.34.1

[PATCH 5/6] media: staging: media: imx6-mipi-csi2: use guard() to simplify code

[Frank Li]

Use guard() to simplify mutex locking. No functional change.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 54 +++++++++++-------------------
 1 file changed, 19 insertions(+), 35 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index f8d0b3b8b250774af51f2aba731e639131aceff9..54e9491d3428686288a5bc9bb58a5a0a25aca696 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -413,21 +413,17 @@ static int csi2_s_stream(struct v4l2_subdev *sd, int enable)
 	struct csi2_dev *csi2 = sd_to_dev(sd);
 	int i, ret = 0;
 
-	mutex_lock(&csi2->lock);
+	guard(mutex)(&csi2->lock);
 
-	if (!csi2->src_sd) {
-		ret = -EPIPE;
-		goto out;
-	}
+	if (!csi2->src_sd)
+		return -EPIPE;
 
 	for (i = 0; i < CSI2_NUM_SRC_PADS; i++) {
 		if (csi2->sink_linked[i])
 			break;
 	}
-	if (i >= CSI2_NUM_SRC_PADS) {
-		ret = -EPIPE;
-		goto out;
-	}
+	if (i >= CSI2_NUM_SRC_PADS)
+		return -EPIPE;
 
 	/*
 	 * enable/disable streaming only if stream_count is
@@ -442,14 +438,12 @@ static int csi2_s_stream(struct v4l2_subdev *sd, int enable)
 	else
 		csi2_stop(csi2);
 	if (ret)
-		goto out;
+		return ret;
 
 update_count:
 	csi2->stream_count += enable ? 1 : -1;
 	if (csi2->stream_count < 0)
 		csi2->stream_count = 0;
-out:
-	mutex_unlock(&csi2->lock);
 	return ret;
 }
 
@@ -467,32 +461,28 @@ static int csi2_link_setup(struct media_entity *entity,
 
 	remote_sd = media_entity_to_v4l2_subdev(remote->entity);
 
-	mutex_lock(&csi2->lock);
+	guard(mutex)(&csi2->lock);
 
 	if (local->flags & MEDIA_PAD_FL_SOURCE) {
 		if (flags & MEDIA_LNK_FL_ENABLED) {
-			if (csi2->sink_linked[local->index - 1]) {
-				ret = -EBUSY;
-				goto out;
-			}
+			if (csi2->sink_linked[local->index - 1])
+				return -EBUSY;
+
 			csi2->sink_linked[local->index - 1] = true;
 		} else {
 			csi2->sink_linked[local->index - 1] = false;
 		}
 	} else {
 		if (flags & MEDIA_LNK_FL_ENABLED) {
-			if (csi2->src_sd) {
-				ret = -EBUSY;
-				goto out;
-			}
+			if (csi2->src_sd)
+				return -EBUSY;
+
 			csi2->src_sd = remote_sd;
 		} else {
 			csi2->src_sd = NULL;
 		}
 	}
 
-out:
-	mutex_unlock(&csi2->lock);
 	return ret;
 }
 
@@ -513,14 +503,12 @@ static int csi2_get_fmt(struct v4l2_subdev *sd,
 	struct csi2_dev *csi2 = sd_to_dev(sd);
 	struct v4l2_mbus_framefmt *fmt;
 
-	mutex_lock(&csi2->lock);
+	guard(mutex)(&csi2->lock);
 
 	fmt = __csi2_get_fmt(csi2, sd_state, sdformat->pad, sdformat->which);
 
 	sdformat->format = *fmt;
 
-	mutex_unlock(&csi2->lock);
-
 	return 0;
 }
 
@@ -530,17 +518,14 @@ static int csi2_set_fmt(struct v4l2_subdev *sd,
 {
 	struct csi2_dev *csi2 = sd_to_dev(sd);
 	struct v4l2_mbus_framefmt *fmt;
-	int ret = 0;
 
 	if (sdformat->pad >= CSI2_NUM_PADS)
 		return -EINVAL;
 
-	mutex_lock(&csi2->lock);
+	guard(mutex)(&csi2->lock);
 
-	if (csi2->stream_count > 0) {
-		ret = -EBUSY;
-		goto out;
-	}
+	if (csi2->stream_count > 0)
+		return -EBUSY;
 
 	/* Output pads mirror active input pad, no limits on input pads */
 	if (sdformat->pad != CSI2_SINK_PAD)
@@ -549,9 +534,8 @@ static int csi2_set_fmt(struct v4l2_subdev *sd,
 	fmt = __csi2_get_fmt(csi2, sd_state, sdformat->pad, sdformat->which);
 
 	*fmt = sdformat->format;
-out:
-	mutex_unlock(&csi2->lock);
-	return ret;
+
+	return 0;
 }
 
 static int csi2_registered(struct v4l2_subdev *sd)

-- 
2.34.1

[PATCH 6/6] media: staging: media: imx6-mipi-csi2: use devm_platform_ioremap_resource() simplify code

[Frank Li]

Use devm_platform_ioremap_resource() simplify code. No functional change.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v4
- add Laurent Pinchart's review tags
- return PTR_ERR(csi2->base) directly.
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index 54e9491d3428686288a5bc9bb58a5a0a25aca696..3d590968483e4f70d284f8abe2e789a7f32e6728 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -711,7 +711,6 @@ static void csi2_nf_cleanup(void *data)
 static int csi2_probe(struct platform_device *pdev)
 {
 	struct csi2_dev *csi2;
-	struct resource *res;
 	int i, ret;
 
 	csi2 = devm_kzalloc(&pdev->dev, sizeof(*csi2), GFP_KERNEL);
@@ -745,15 +744,9 @@ static int csi2_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		v4l2_err(&csi2->sd, "failed to get platform resources\n");
-		return -ENODEV;
-	}
-
-	csi2->base = devm_ioremap(&pdev->dev, res->start, PAGE_SIZE);
-	if (!csi2->base)
-		return -ENOMEM;
+	csi2->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(csi2->base))
+		return PTR_ERR(csi2->base);
 
 	ret = devm_mutex_init(&pdev->dev, &csi2->lock);
 	if (ret)

-- 
2.34.1

Re: [PATCH 6/6] media: staging: media: imx6-mipi-csi2: use devm_platform_ioremap_resource() simplify code

[Philipp Zabel]

On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> Use devm_platform_ioremap_resource() simplify code. No functional change.
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

Re: [PATCH 3/6] media: staging: media: imx6-mipi-csi2: use devm_clk_bulk_get_all() to fetch clocks

[Philipp Zabel]

On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> Use devm_clk_bulk_get_all_enabled() helper to simplify clock handling.
> 
> Defer all clock prepare and enable to csi2_start(), which previous only
> enable pix clock here.
> 
> Do that safely because there are not register access before csi2_start().

What about log_status()?

regards
Philipp

Re: [PATCH 4/6] media: staging: media: imx6-mipi-csi2: use devm_mutex_init() to simplify code

[Philipp Zabel]

On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> Use devm_mutex_init() to simplify the code. No functional change.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

Although I think this should come before patches 2 and 3.

regards
Philipp

Re: [PATCH 5/6] media: staging: media: imx6-mipi-csi2: use guard() to simplify code

[Philipp Zabel]

On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> Use guard() to simplify mutex locking. No functional change.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/staging/media/imx/imx6-mipi-csi2.c | 54 +++++++++++-------------------
>  1 file changed, 19 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
> index f8d0b3b8b250774af51f2aba731e639131aceff9..54e9491d3428686288a5bc9bb58a5a0a25aca696 100644
> --- a/drivers/staging/media/imx/imx6-mipi-csi2.c
> +++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
> @@ -413,21 +413,17 @@ static int csi2_s_stream(struct v4l2_subdev *sd, int enable)
>  	struct csi2_dev *csi2 = sd_to_dev(sd);
>  	int i, ret = 0;
>  
> -	mutex_lock(&csi2->lock);
> +	guard(mutex)(&csi2->lock);
>  
> -	if (!csi2->src_sd) {
> -		ret = -EPIPE;
> -		goto out;
> -	}
> +	if (!csi2->src_sd)
> +		return -EPIPE;
>  
>  	for (i = 0; i < CSI2_NUM_SRC_PADS; i++) {
>  		if (csi2->sink_linked[i])
>  			break;
>  	}
> -	if (i >= CSI2_NUM_SRC_PADS) {
> -		ret = -EPIPE;
> -		goto out;
> -	}
> +	if (i >= CSI2_NUM_SRC_PADS)
> +		return -EPIPE;
>  
>  	/*
>  	 * enable/disable streaming only if stream_count is
> @@ -442,14 +438,12 @@ static int csi2_s_stream(struct v4l2_subdev *sd, int enable)
>  	else
>  		csi2_stop(csi2);
>  	if (ret)
> -		goto out;
> +		return ret;
>  
>  update_count:
>  	csi2->stream_count += enable ? 1 : -1;
>  	if (csi2->stream_count < 0)
>  		csi2->stream_count = 0;
> -out:
> -	mutex_unlock(&csi2->lock);
>  	return ret;

This is mixing goto and cleanup in the same function, which the scope-
based cleanup helpers documentation suggests shouldn't be done.

In this case I see no problem because we only jump to update_count from
under the lock, but since issues with gotos around automatic cleanup
are easy to miss, I think it would be better to also turn the
update_count jump into a conditional block.


regards
Philipp

Re: [PATCH 2/6] media: staging: media: imx6-mipi-csi2: use devm_add_action_or_reset() to simplify code

[Philipp Zabel]

On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> Use devm_add_action_or_reset() to simplify the code. No functional change.
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---
>  drivers/staging/media/imx/imx6-mipi-csi2.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
> index 42256441b881d9f132ad7ff899d6f1e35643b4ac..eba9a650030f5e380aa900b94728ad375171c6a5 100644
> --- a/drivers/staging/media/imx/imx6-mipi-csi2.c
> +++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
> @@ -716,6 +716,14 @@ static int csi2_async_register(struct csi2_dev *csi2)
>  	return ret;
>  }
>  
> +static void csi2_nf_cleanup(void *data)
> +{
> +	struct csi2_dev *csi2 = data;
> +
> +	v4l2_async_nf_unregister(&csi2->notifier);
> +	v4l2_async_nf_cleanup(&csi2->notifier);
> +}
> +
>  static int csi2_probe(struct platform_device *pdev)
>  {
>  	struct csi2_dev *csi2;
> @@ -749,6 +757,10 @@ static int csi2_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	ret = devm_add_action_or_reset(&pdev->dev, csi2_nf_cleanup, csi2);
> +	if (ret)
> +		return ret;
> +
>  	csi2->pllref_clk = devm_clk_get(&pdev->dev, "ref");
>  	if (IS_ERR(csi2->pllref_clk)) {
>  		v4l2_err(&csi2->sd, "failed to get pll reference clock\n");
> @@ -800,8 +812,6 @@ static int csi2_probe(struct platform_device *pdev)
>  	return 0;
>  
>  clean_notifier:
> -	v4l2_async_nf_unregister(&csi2->notifier);
> -	v4l2_async_nf_cleanup(&csi2->notifier);
>  	clk_disable_unprepare(csi2->dphy_clk);
>  pllref_off:
>  	clk_disable_unprepare(csi2->pllref_clk);
> @@ -815,8 +825,6 @@ static void csi2_remove(struct platform_device *pdev)
>  	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
>  	struct csi2_dev *csi2 = sd_to_dev(sd);
>  
> -	v4l2_async_nf_unregister(&csi2->notifier);
> -	v4l2_async_nf_cleanup(&csi2->notifier);
>  	v4l2_async_unregister_subdev(sd);

This effectively moves the notifier unregister after the subdev
unregister. Is that safe to do?


regards
Philipp

Re: [PATCH 1/6] media: staging: media: imx6-mipi-csi2: replace space with tab for alignment

[Philipp Zabel]

On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> Replace space with tab to follow coding convention. No functional change.

Which convention? To be honest, this feels a bit like unnecessary churn
to me.

> Signed-off-by: Frank Li <Frank.Li@nxp.com>
>
> ---
>  drivers/staging/media/imx/imx6-mipi-csi2.c | 92 +++++++++++++++---------------
>  1 file changed, 46 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
> index dd8c7b3233bccfc34b59e0f0ff813b36752e1526..42256441b881d9f132ad7ff899d6f1e35643b4ac 100644
> --- a/drivers/staging/media/imx/imx6-mipi-csi2.c
> +++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
> @@ -23,65 +23,65 @@
>   * there must be 5 pads: 1 input pad from sensor, and
>   * the 4 virtual channel output pads
>   */
> -#define CSI2_SINK_PAD       0
> -#define CSI2_NUM_SINK_PADS  1
> -#define CSI2_NUM_SRC_PADS   4
> -#define CSI2_NUM_PADS       5
> +#define CSI2_SINK_PAD		0
> +#define CSI2_NUM_SINK_PADS	1
> +#define CSI2_NUM_SRC_PADS	4
> +#define CSI2_NUM_PADS		5
>  
>  /*
>   * The default maximum bit-rate per lane in Mbps, if the
>   * source subdev does not provide V4L2_CID_LINK_FREQ.
>   */
> -#define CSI2_DEFAULT_MAX_MBPS 849
> +#define CSI2_DEFAULT_MAX_MBPS	849

Personally, I like these changes.

>  struct csi2_dev {
> -	struct device          *dev;
> -	struct v4l2_subdev      sd;
> -	struct v4l2_async_notifier notifier;
> -	struct media_pad       pad[CSI2_NUM_PADS];
> -	struct clk             *dphy_clk;
> -	struct clk             *pllref_clk;
> -	struct clk             *pix_clk; /* what is this? */
> -	void __iomem           *base;
> -
> -	struct v4l2_subdev	*remote;
> -	unsigned int		remote_pad;
> -	unsigned short		data_lanes;
> +	struct device			*dev;
> +	struct v4l2_subdev		sd;
> +	struct v4l2_async_notifier	notifier;
> +	struct media_pad		pad[CSI2_NUM_PADS];
> +	struct clk			*dphy_clk;
> +	struct clk			*pllref_clk;
> +	struct clk			*pix_clk; /* what is this? */
> +	void __iomem			*base;
> +
> +	struct v4l2_subdev		*remote;
> +	unsigned int			remote_pad;
> +	unsigned short			data_lanes;
>  
>  	/* lock to protect all members below */
> -	struct mutex lock;
> +	struct mutex			lock;
>  
> -	struct v4l2_mbus_framefmt format_mbus;
> +	struct v4l2_mbus_framefmt	format_mbus;
>  
> -	int                     stream_count;
> -	struct v4l2_subdev      *src_sd;
> -	bool                    sink_linked[CSI2_NUM_SRC_PADS];
> +	int				stream_count;
> +	struct v4l2_subdev		*src_sd;
> +	bool				sink_linked[CSI2_NUM_SRC_PADS];
>  };

Here I'd prefer just a single space between type and identifier.

regards
Philipp

Re: [PATCH 3/6] media: staging: media: imx6-mipi-csi2: use devm_clk_bulk_get_all() to fetch clocks

[Frank Li]

On Mon, Nov 10, 2025 at 09:22:30AM +0100, Philipp Zabel wrote:
> On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> > Use devm_clk_bulk_get_all_enabled() helper to simplify clock handling.
> >
> > Defer all clock prepare and enable to csi2_start(), which previous only
> > enable pix clock here.
> >
> > Do that safely because there are not register access before csi2_start().
>
> What about log_status()?

Good capture, It should add clk_get/put in log_status().  Plan to change to
use runtime pm to manage clock later.

Frank
>
> regards
> Philipp

Re: [PATCH 2/6] media: staging: media: imx6-mipi-csi2: use devm_add_action_or_reset() to simplify code

[Frank Li]

On Mon, Nov 10, 2025 at 09:28:24AM +0100, Philipp Zabel wrote:
> On Fr, 2025-11-07 at 15:44 -0500, Frank Li wrote:
> > Use devm_add_action_or_reset() to simplify the code. No functional change.
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> >  drivers/staging/media/imx/imx6-mipi-csi2.c | 16 ++++++++++++----
> >  1 file changed, 12 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
> > index 42256441b881d9f132ad7ff899d6f1e35643b4ac..eba9a650030f5e380aa900b94728ad375171c6a5 100644
> > --- a/drivers/staging/media/imx/imx6-mipi-csi2.c
> > +++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
> > @@ -716,6 +716,14 @@ static int csi2_async_register(struct csi2_dev *csi2)
> >  	return ret;
> >  }
> >
> > +static void csi2_nf_cleanup(void *data)
> > +{
> > +	struct csi2_dev *csi2 = data;
> > +
> > +	v4l2_async_nf_unregister(&csi2->notifier);
> > +	v4l2_async_nf_cleanup(&csi2->notifier);
> > +}
> > +
> >  static int csi2_probe(struct platform_device *pdev)
> >  {
> >  	struct csi2_dev *csi2;
> > @@ -749,6 +757,10 @@ static int csi2_probe(struct platform_device *pdev)
> >  	if (ret)
> >  		return ret;
> >
> > +	ret = devm_add_action_or_reset(&pdev->dev, csi2_nf_cleanup, csi2);
> > +	if (ret)
> > +		return ret;
> > +
> >  	csi2->pllref_clk = devm_clk_get(&pdev->dev, "ref");
> >  	if (IS_ERR(csi2->pllref_clk)) {
> >  		v4l2_err(&csi2->sd, "failed to get pll reference clock\n");
> > @@ -800,8 +812,6 @@ static int csi2_probe(struct platform_device *pdev)
> >  	return 0;
> >
> >  clean_notifier:
> > -	v4l2_async_nf_unregister(&csi2->notifier);
> > -	v4l2_async_nf_cleanup(&csi2->notifier);
> >  	clk_disable_unprepare(csi2->dphy_clk);
> >  pllref_off:
> >  	clk_disable_unprepare(csi2->pllref_clk);
> > @@ -815,8 +825,6 @@ static void csi2_remove(struct platform_device *pdev)
> >  	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
> >  	struct csi2_dev *csi2 = sd_to_dev(sd);
> >
> > -	v4l2_async_nf_unregister(&csi2->notifier);
> > -	v4l2_async_nf_cleanup(&csi2->notifier);
> >  	v4l2_async_unregister_subdev(sd);
>
> This effectively moves the notifier unregister after the subdev
> unregister. Is that safe to do?

Good question:

I think, it'd better to provide devm_v4l2_*() helper functions for these.
I am not sure why there are not devm_v4l2*() helper functions now.

Frank
>
>
> regards
> Philipp