[PATCH v4 09/25] media: i2c: imx258: Add support for running on 2 CSI data lanes

[git@luigi311.com]

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

Extends the driver to also support 2 data lanes.
Frame rates are obviously more restricted on 2 lanes, but some
hardware simply hasn't wired more up.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Luis Garcia <git@luigi311.com>
---
 drivers/media/i2c/imx258.c | 214 ++++++++++++++++++++++++++++++++-----
 1 file changed, 190 insertions(+), 24 deletions(-)

diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c
index e4b1b3cbbde5..8f792f0e0738 100644
--- a/drivers/media/i2c/imx258.c
+++ b/drivers/media/i2c/imx258.c
@@ -86,12 +86,18 @@ struct imx258_reg_list {
 	const struct imx258_reg *regs;
 };
 
+enum {
+	IMX258_2_LANE_MODE,
+	IMX258_4_LANE_MODE,
+	IMX258_LANE_CONFIGS,
+};
+
 /* Link frequency config */
 struct imx258_link_freq_config {
 	u32 pixels_per_line;
 
 	/* PLL registers for this link frequency */
-	struct imx258_reg_list reg_list;
+	struct imx258_reg_list reg_list[IMX258_LANE_CONFIGS];
 };
 
 /* Mode : resolution and related config&values */
@@ -111,8 +117,34 @@ struct imx258_mode {
 	struct imx258_reg_list reg_list;
 };
 
-/* 4208x3120 needs 1267Mbps/lane, 4 lanes */
-static const struct imx258_reg mipi_1267mbps_19_2mhz[] = {
+/*
+ * 4208x3120 @ 30 fps needs 1267Mbps/lane, 4 lanes.
+ * To avoid further computation of clock settings, adopt the same per
+ * lane data rate when using 2 lanes, thus allowing a maximum of 15fps.
+ */
+static const struct imx258_reg mipi_1267mbps_19_2mhz_2l[] = {
+	{ 0x0136, 0x13 },
+	{ 0x0137, 0x33 },
+	{ 0x0301, 0x0A },
+	{ 0x0303, 0x02 },
+	{ 0x0305, 0x03 },
+	{ 0x0306, 0x00 },
+	{ 0x0307, 0xC6 },
+	{ 0x0309, 0x0A },
+	{ 0x030B, 0x01 },
+	{ 0x030D, 0x02 },
+	{ 0x030E, 0x00 },
+	{ 0x030F, 0xD8 },
+	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x01 },
+	{ 0x0820, 0x09 },
+	{ 0x0821, 0xa6 },
+	{ 0x0822, 0x66 },
+	{ 0x0823, 0x66 },
+};
+
+static const struct imx258_reg mipi_1267mbps_19_2mhz_4l[] = {
 	{ 0x0136, 0x13 },
 	{ 0x0137, 0x33 },
 	{ 0x0301, 0x05 },
@@ -126,16 +158,18 @@ static const struct imx258_reg mipi_1267mbps_19_2mhz[] = {
 	{ 0x030E, 0x00 },
 	{ 0x030F, 0xD8 },
 	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x03 },
 	{ 0x0820, 0x13 },
 	{ 0x0821, 0x4C },
 	{ 0x0822, 0xCC },
 	{ 0x0823, 0xCC },
 };
 
-static const struct imx258_reg mipi_1272mbps_24mhz[] = {
+static const struct imx258_reg mipi_1272mbps_24mhz_2l[] = {
 	{ 0x0136, 0x18 },
 	{ 0x0137, 0x00 },
-	{ 0x0301, 0x05 },
+	{ 0x0301, 0x0a },
 	{ 0x0303, 0x02 },
 	{ 0x0305, 0x04 },
 	{ 0x0306, 0x00 },
@@ -146,13 +180,59 @@ static const struct imx258_reg mipi_1272mbps_24mhz[] = {
 	{ 0x030E, 0x00 },
 	{ 0x030F, 0xD8 },
 	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x01 },
 	{ 0x0820, 0x13 },
 	{ 0x0821, 0x4C },
 	{ 0x0822, 0xCC },
 	{ 0x0823, 0xCC },
 };
 
-static const struct imx258_reg mipi_640mbps_19_2mhz[] = {
+static const struct imx258_reg mipi_1272mbps_24mhz_4l[] = {
+	{ 0x0136, 0x18 },
+	{ 0x0137, 0x00 },
+	{ 0x0301, 0x05 },
+	{ 0x0303, 0x02 },
+	{ 0x0305, 0x04 },
+	{ 0x0306, 0x00 },
+	{ 0x0307, 0xD4 },
+	{ 0x0309, 0x0A },
+	{ 0x030B, 0x01 },
+	{ 0x030D, 0x02 },
+	{ 0x030E, 0x00 },
+	{ 0x030F, 0xD8 },
+	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x03 },
+	{ 0x0820, 0x13 },
+	{ 0x0821, 0xE0 },
+	{ 0x0822, 0x00 },
+	{ 0x0823, 0x00 },
+};
+
+static const struct imx258_reg mipi_640mbps_19_2mhz_2l[] = {
+	{ 0x0136, 0x13 },
+	{ 0x0137, 0x33 },
+	{ 0x0301, 0x05 },
+	{ 0x0303, 0x02 },
+	{ 0x0305, 0x03 },
+	{ 0x0306, 0x00 },
+	{ 0x0307, 0x64 },
+	{ 0x0309, 0x0A },
+	{ 0x030B, 0x01 },
+	{ 0x030D, 0x02 },
+	{ 0x030E, 0x00 },
+	{ 0x030F, 0xD8 },
+	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x01 },
+	{ 0x0820, 0x05 },
+	{ 0x0821, 0x00 },
+	{ 0x0822, 0x00 },
+	{ 0x0823, 0x00 },
+};
+
+static const struct imx258_reg mipi_640mbps_19_2mhz_4l[] = {
 	{ 0x0136, 0x13 },
 	{ 0x0137, 0x33 },
 	{ 0x0301, 0x05 },
@@ -166,13 +246,37 @@ static const struct imx258_reg mipi_640mbps_19_2mhz[] = {
 	{ 0x030E, 0x00 },
 	{ 0x030F, 0xD8 },
 	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x03 },
+	{ 0x0820, 0x0A },
+	{ 0x0821, 0x00 },
+	{ 0x0822, 0x00 },
+	{ 0x0823, 0x00 },
+};
+
+static const struct imx258_reg mipi_642mbps_24mhz_2l[] = {
+	{ 0x0136, 0x18 },
+	{ 0x0137, 0x00 },
+	{ 0x0301, 0x0A },
+	{ 0x0303, 0x02 },
+	{ 0x0305, 0x04 },
+	{ 0x0306, 0x00 },
+	{ 0x0307, 0x6B },
+	{ 0x0309, 0x0A },
+	{ 0x030B, 0x01 },
+	{ 0x030D, 0x02 },
+	{ 0x030E, 0x00 },
+	{ 0x030F, 0xD8 },
+	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x01 },
 	{ 0x0820, 0x0A },
 	{ 0x0821, 0x00 },
 	{ 0x0822, 0x00 },
 	{ 0x0823, 0x00 },
 };
 
-static const struct imx258_reg mipi_642mbps_24mhz[] = {
+static const struct imx258_reg mipi_642mbps_24mhz_4l[] = {
 	{ 0x0136, 0x18 },
 	{ 0x0137, 0x00 },
 	{ 0x0301, 0x05 },
@@ -186,6 +290,8 @@ static const struct imx258_reg mipi_642mbps_24mhz[] = {
 	{ 0x030E, 0x00 },
 	{ 0x030F, 0xD8 },
 	{ 0x0310, 0x00 },
+
+	{ 0x0114, 0x03 },
 	{ 0x0820, 0x0A },
 	{ 0x0821, 0x00 },
 	{ 0x0822, 0x00 },
@@ -240,7 +346,6 @@ static const struct imx258_reg mode_common_regs[] = {
 	{ 0x5F05, 0xED },
 	{ 0x0112, 0x0A },
 	{ 0x0113, 0x0A },
-	{ 0x0114, 0x03 },
 	{ 0x0342, 0x14 },
 	{ 0x0343, 0xE8 },
 	{ 0x0344, 0x00 },
@@ -359,11 +464,13 @@ enum {
 
 /*
  * pixel_rate = link_freq * data-rate * nr_of_lanes / bits_per_sample
- * data rate => double data rate; number of lanes => 4; bits per pixel => 10
+ * data rate => double data rate;
+ * number of lanes => (configurable 2 or 4);
+ * bits per pixel => 10
  */
-static u64 link_freq_to_pixel_rate(u64 f)
+static u64 link_freq_to_pixel_rate(u64 f, unsigned int nlanes)
 {
-	f *= 2 * 4;
+	f *= 2 * nlanes;
 	do_div(f, 10);
 
 	return f;
@@ -386,15 +493,27 @@ static const struct imx258_link_freq_config link_freq_configs_19_2[] = {
 	[IMX258_LINK_FREQ_1267MBPS] = {
 		.pixels_per_line = IMX258_PPL_DEFAULT,
 		.reg_list = {
-			.num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz),
-			.regs = mipi_1267mbps_19_2mhz,
+			[IMX258_2_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz_2l),
+				.regs = mipi_1267mbps_19_2mhz_2l,
+			},
+			[IMX258_4_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_1267mbps_19_2mhz_4l),
+				.regs = mipi_1267mbps_19_2mhz_4l,
+			},
 		}
 	},
 	[IMX258_LINK_FREQ_640MBPS] = {
 		.pixels_per_line = IMX258_PPL_DEFAULT,
 		.reg_list = {
-			.num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz),
-			.regs = mipi_640mbps_19_2mhz,
+			[IMX258_2_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz_2l),
+				.regs = mipi_640mbps_19_2mhz_2l,
+			},
+			[IMX258_4_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_640mbps_19_2mhz_4l),
+				.regs = mipi_640mbps_19_2mhz_4l,
+			},
 		}
 	},
 };
@@ -403,15 +522,27 @@ static const struct imx258_link_freq_config link_freq_configs_24[] = {
 	[IMX258_LINK_FREQ_1267MBPS] = {
 		.pixels_per_line = IMX258_PPL_DEFAULT,
 		.reg_list = {
-			.num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz),
-			.regs = mipi_1272mbps_24mhz,
+			[IMX258_2_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz_2l),
+				.regs = mipi_1272mbps_24mhz_2l,
+			},
+			[IMX258_4_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_1272mbps_24mhz_4l),
+				.regs = mipi_1272mbps_24mhz_4l,
+			},
 		}
 	},
 	[IMX258_LINK_FREQ_640MBPS] = {
 		.pixels_per_line = IMX258_PPL_DEFAULT,
 		.reg_list = {
-			.num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz),
-			.regs = mipi_642mbps_24mhz,
+			[IMX258_2_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz_2l),
+				.regs = mipi_642mbps_24mhz_2l,
+			},
+			[IMX258_4_LANE_MODE] = {
+				.num_of_regs = ARRAY_SIZE(mipi_642mbps_24mhz_4l),
+				.regs = mipi_642mbps_24mhz_4l,
+			},
 		}
 	},
 };
@@ -470,6 +601,7 @@ struct imx258 {
 
 	const struct imx258_link_freq_config *link_freq_configs;
 	const s64 *link_freq_menu_items;
+	unsigned int nlanes;
 
 	/*
 	 * Mutex for serialized access:
@@ -775,7 +907,7 @@ static int imx258_set_pad_format(struct v4l2_subdev *sd,
 		__v4l2_ctrl_s_ctrl(imx258->link_freq, mode->link_freq_index);
 
 		link_freq = imx258->link_freq_menu_items[mode->link_freq_index];
-		pixel_rate = link_freq_to_pixel_rate(link_freq);
+		pixel_rate = link_freq_to_pixel_rate(link_freq, imx258->nlanes);
 		__v4l2_ctrl_s_ctrl_int64(imx258->pixel_rate, pixel_rate);
 		/* Update limits and set FPS to default */
 		vblank_def = imx258->cur_mode->vts_def -
@@ -804,11 +936,13 @@ static int imx258_start_streaming(struct imx258 *imx258)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
 	const struct imx258_reg_list *reg_list;
+	const struct imx258_link_freq_config *link_freq_cfg;
 	int ret, link_freq_index;
 
 	/* Setup PLL */
 	link_freq_index = imx258->cur_mode->link_freq_index;
-	reg_list = &imx258->link_freq_configs[link_freq_index].reg_list;
+	link_freq_cfg = &imx258->link_freq_configs[link_freq_index];
+	reg_list = &link_freq_cfg->reg_list[imx258->nlanes == 2 ? 0 : 1];
 	ret = imx258_write_regs(imx258, reg_list->regs, reg_list->num_of_regs);
 	if (ret) {
 		dev_err(&client->dev, "%s failed to set plls\n", __func__);
@@ -1026,9 +1160,11 @@ static int imx258_init_controls(struct imx258 *imx258)
 		vflip->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 
 	pixel_rate_max =
-		link_freq_to_pixel_rate(imx258->link_freq_menu_items[0]);
+		link_freq_to_pixel_rate(imx258->link_freq_menu_items[0],
+					imx258->nlanes);
 	pixel_rate_min =
-		link_freq_to_pixel_rate(imx258->link_freq_menu_items[1]);
+		link_freq_to_pixel_rate(imx258->link_freq_menu_items[1],
+					imx258->nlanes);
 	/* By default, PIXEL_RATE is read only */
 	imx258->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops,
 				V4L2_CID_PIXEL_RATE,
@@ -1125,6 +1261,10 @@ static int imx258_get_regulators(struct imx258 *imx258,
 static int imx258_probe(struct i2c_client *client)
 {
 	struct imx258 *imx258;
+	struct fwnode_handle *endpoint;
+	struct v4l2_fwnode_endpoint ep = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY
+	};
 	int ret;
 	u32 val = 0;
 
@@ -1165,13 +1305,35 @@ static int imx258_probe(struct i2c_client *client)
 		return -EINVAL;
 	}
 
+	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(&client->dev), NULL);
+	if (!endpoint) {
+		dev_err(&client->dev, "Endpoint node not found\n");
+		return -EINVAL;
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);
+	fwnode_handle_put(endpoint);
+	if (ret) {
+		dev_err(&client->dev, "Parsing endpoint node failed\n");
+		return ret;
+	}
+
+	/* Get number of data lanes */
+	imx258->nlanes = ep.bus.mipi_csi2.num_data_lanes;
+	if (imx258->nlanes != 2 && imx258->nlanes != 4) {
+		dev_err(&client->dev, "Invalid data lanes: %u\n",
+			imx258->nlanes);
+		ret = -EINVAL;
+		goto error_endpoint_free;
+	}
+
 	/* Initialize subdev */
 	v4l2_i2c_subdev_init(&imx258->sd, client, &imx258_subdev_ops);
 
 	/* Will be powered off via pm_runtime_idle */
 	ret = imx258_power_on(&client->dev);
 	if (ret)
-		return ret;
+		goto error_endpoint_free;
 
 	/* Check module identity */
 	ret = imx258_identify_module(imx258);
@@ -1204,6 +1366,7 @@ static int imx258_probe(struct i2c_client *client)
 	pm_runtime_set_active(&client->dev);
 	pm_runtime_enable(&client->dev);
 	pm_runtime_idle(&client->dev);
+	v4l2_fwnode_endpoint_free(&ep);
 
 	return 0;
 
@@ -1216,6 +1379,9 @@ static int imx258_probe(struct i2c_client *client)
 error_identify:
 	imx258_power_off(&client->dev);
 
+error_endpoint_free:
+	v4l2_fwnode_endpoint_free(&ep);
+
 	return ret;
 }
 
-- 
2.44.0