openwrt/target/linux/bcm27xx/patches-6.6/950-1379-media-i2c-imx477-Add-options-for-slightly-modifying-.patch

From 35e50ee3d66e014d869f0d7a3468bef964d26d32 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Thu, 14 Nov 2024 13:14:02 +0000
Subject: [PATCH] media: i2c: imx477: Add options for slightly modifying the
 link freq

The default link frequency of 450MHz has been noted to interfere
with GPS if they are in close proximty.
Add the option for 453 and 456MHz to move the signal slightly out
of the band. (447MHz can not be offered as corruption is then observed
on the 133x992 10bit mode).

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

fixup imx477 gps
---
 drivers/media/i2c/imx477.c | 86 +++++++++++++++++++++++++++++---------
 1 file changed, 67 insertions(+), 19 deletions(-)

--- a/drivers/media/i2c/imx477.c
+++ b/drivers/media/i2c/imx477.c
@@ -164,8 +164,48 @@ struct imx477_mode {
 	struct imx477_reg_list reg_list;
 };
 
-static const s64 imx477_link_freq_menu[] = {
-	IMX477_DEFAULT_LINK_FREQ,
+/* Link frequency setup */
+enum {
+	IMX477_LINK_FREQ_450MHZ,
+	IMX477_LINK_FREQ_453MHZ,
+	IMX477_LINK_FREQ_456MHZ,
+};
+
+static const s64 link_freqs[] = {
+	[IMX477_LINK_FREQ_450MHZ] = 450000000,
+	[IMX477_LINK_FREQ_453MHZ] = 453000000,
+	[IMX477_LINK_FREQ_456MHZ] = 456000000,
+};
+
+/* 450MHz is the nominal "default" link frequency */
+static const struct imx477_reg link_450Mhz_regs[] = {
+	{0x030E, 0x00},
+	{0x030F, 0x96},
+};
+
+static const struct imx477_reg link_453Mhz_regs[] = {
+	{0x030E, 0x00},
+	{0x030F, 0x97},
+};
+
+static const struct imx477_reg link_456Mhz_regs[] = {
+	{0x030E, 0x00},
+	{0x030F, 0x98},
+};
+
+static const struct imx477_reg_list link_freq_regs[] = {
+	[IMX477_LINK_FREQ_450MHZ] = {
+		.regs = link_450Mhz_regs,
+		.num_of_regs = ARRAY_SIZE(link_450Mhz_regs)
+	},
+	[IMX477_LINK_FREQ_453MHZ] = {
+		.regs = link_453Mhz_regs,
+		.num_of_regs = ARRAY_SIZE(link_453Mhz_regs)
+	},
+	[IMX477_LINK_FREQ_456MHZ] = {
+		.regs = link_456Mhz_regs,
+		.num_of_regs = ARRAY_SIZE(link_456Mhz_regs)
+	},
 };
 
 static const struct imx477_reg mode_common_regs[] = {
@@ -558,8 +598,6 @@ static const struct imx477_reg mode_4056
 	{0x0309, 0x0c},
 	{0x030b, 0x02},
 	{0x030d, 0x02},
-	{0x030e, 0x00},
-	{0x030f, 0x96},
 	{0x0310, 0x01},
 	{0x0820, 0x07},
 	{0x0821, 0x08},
@@ -659,8 +697,6 @@ static const struct imx477_reg mode_2028
 	{0x0309, 0x0c},
 	{0x030b, 0x02},
 	{0x030d, 0x02},
-	{0x030e, 0x00},
-	{0x030f, 0x96},
 	{0x0310, 0x01},
 	{0x0820, 0x07},
 	{0x0821, 0x08},
@@ -760,8 +796,6 @@ static const struct imx477_reg mode_2028
 	{0x0309, 0x0c},
 	{0x030b, 0x02},
 	{0x030d, 0x02},
-	{0x030e, 0x00},
-	{0x030f, 0x96},
 	{0x0310, 0x01},
 	{0x0820, 0x07},
 	{0x0821, 0x08},
@@ -890,8 +924,6 @@ static const struct imx477_reg mode_1332
 	{0x0309, 0x0a},
 	{0x030b, 0x02},
 	{0x030d, 0x02},
-	{0x030e, 0x00},
-	{0x030f, 0x96},
 	{0x0310, 0x01},
 	{0x0820, 0x07},
 	{0x0821, 0x08},
@@ -1121,6 +1153,8 @@ struct imx477 {
 	struct v4l2_ctrl *vblank;
 	struct v4l2_ctrl *hblank;
 
+	unsigned int link_freq_idx;
+
 	/* Current mode */
 	const struct imx477_mode *mode;
 
@@ -1712,7 +1746,7 @@ static int imx477_get_selection(struct v
 static int imx477_start_streaming(struct imx477 *imx477)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&imx477->sd);
-	const struct imx477_reg_list *reg_list;
+	const struct imx477_reg_list *reg_list, *freq_regs;
 	const struct imx477_reg_list *extra_regs;
 	int ret, tm;
 
@@ -1725,6 +1759,13 @@ static int imx477_start_streaming(struct
 						extra_regs->num_of_regs);
 		}
 
+		if (!ret) {
+			/* Update the link frequency registers */
+			freq_regs = &link_freq_regs[imx477->link_freq_idx];
+			ret = imx477_write_regs(imx477, freq_regs->regs,
+						freq_regs->num_of_regs);
+		}
+
 		if (ret) {
 			dev_err(&client->dev, "%s failed to set common settings\n",
 				__func__);
@@ -2010,9 +2051,8 @@ static int imx477_init_controls(struct i
 	/* LINK_FREQ is also read only */
 	imx477->link_freq =
 		v4l2_ctrl_new_int_menu(ctrl_hdlr, &imx477_ctrl_ops,
-				       V4L2_CID_LINK_FREQ,
-				       ARRAY_SIZE(imx477_link_freq_menu) - 1, 0,
-				       imx477_link_freq_menu);
+				       V4L2_CID_LINK_FREQ, 1, 0,
+				       &link_freqs[imx477->link_freq_idx]);
 	if (imx477->link_freq)
 		imx477->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 
@@ -2110,13 +2150,14 @@ static void imx477_free_controls(struct
 	mutex_destroy(&imx477->mutex);
 }
 
-static int imx477_check_hwcfg(struct device *dev)
+static int imx477_check_hwcfg(struct device *dev, struct imx477 *imx477)
 {
 	struct fwnode_handle *endpoint;
 	struct v4l2_fwnode_endpoint ep_cfg = {
 		.bus_type = V4L2_MBUS_CSI2_DPHY
 	};
 	int ret = -EINVAL;
+	int i;
 
 	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
 	if (!endpoint) {
@@ -2141,11 +2182,18 @@ static int imx477_check_hwcfg(struct dev
 		goto error_out;
 	}
 
-	if (ep_cfg.nr_of_link_frequencies != 1 ||
-	    ep_cfg.link_frequencies[0] != IMX477_DEFAULT_LINK_FREQ) {
+	for (i = 0; i < ARRAY_SIZE(link_freqs); i++) {
+		if (link_freqs[i] == ep_cfg.link_frequencies[0]) {
+			imx477->link_freq_idx = i;
+			break;
+		}
+	}
+
+	if (i == ARRAY_SIZE(link_freqs)) {
 		dev_err(dev, "Link frequency not supported: %lld\n",
 			ep_cfg.link_frequencies[0]);
-		goto error_out;
+			ret = -EINVAL;
+			goto error_out;
 	}
 
 	ret = 0;
@@ -2206,7 +2254,7 @@ static int imx477_probe(struct i2c_clien
 		(const struct imx477_compatible_data *)match->data;
 
 	/* Check the hardware configuration in device tree */
-	if (imx477_check_hwcfg(dev))
+	if (imx477_check_hwcfg(dev, imx477))
 		return -EINVAL;
 
 	/* Default the trigger mode from OF to -1, which means invalid */