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From:   Andrey Konovalov <andrey.konovalov@linaro.org>
To:     mchehab@kernel.org, sakari.ailus@iki.fi,
        manivannan.sadhasivam@linaro.org
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        c.barrett@framos.com, a.brela@framos.com, peter.griffin@linaro.org,
        Andrey Konovalov <andrey.konovalov@linaro.org>
Subject: [PATCH v3 05/10] media: i2c: imx290: Add configurable link frequency and pixel rate
Date:   Sun, 24 May 2020 22:25:00 +0300
Message-Id: <20200524192505.20682-6-andrey.konovalov@linaro.org>
In-Reply-To: <20200524192505.20682-1-andrey.konovalov@linaro.org>
References: <20200524192505.20682-1-andrey.konovalov@linaro.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

IMX290 operates with multiple link frequency and pixel rate combinations.
The initial driver used a single setting for both but since we now have
the lane count support in place, let's add configurable link frequency
and pixel rate.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
---
 drivers/media/i2c/imx290.c | 100 ++++++++++++++++++++++++-------------
 1 file changed, 66 insertions(+), 34 deletions(-)

diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c
index a361c9ac8bd5..e800557cf423 100644
--- a/drivers/media/i2c/imx290.c
+++ b/drivers/media/i2c/imx290.c
@@ -38,8 +38,6 @@
 #define IMX290_HMAX_2_720 0x19C8
 #define IMX290_HMAX_4_720 0x0CE4
 
-#define IMX290_DEFAULT_LINK_FREQ 445500000
-
 static const char * const imx290_supply_name[] = {
 	"vdda",
 	"vddd",
@@ -56,8 +54,6 @@ struct imx290_regval {
 struct imx290_mode {
 	u32 width;
 	u32 height;
-	u32 pixel_rate;
-	u32 link_freq_index;
 
 	const struct imx290_regval *data;
 	u32 data_size;
@@ -248,8 +244,13 @@ static const struct imx290_regval imx290_10bit_settings[] = {
 };
 
 /* supported link frequencies */
-static const s64 imx290_link_freq[] = {
-	IMX290_DEFAULT_LINK_FREQ,
+static const s64 imx290_link_freq_2lanes[] = {
+	891000000, /* 1920x1080 -  2 lane */
+	594000000, /* 1280x720  -  2 lane */
+};
+static const s64 imx290_link_freq_4lanes[] = {
+	445500000, /* 1920x1080 -  4 lane */
+	297000000, /* 1280x720  -  4 lane */
 };
 
 /* Mode configs */
@@ -259,16 +260,12 @@ static const struct imx290_mode imx290_modes[] = {
 		.height = 1080,
 		.data = imx290_1080p_settings,
 		.data_size = ARRAY_SIZE(imx290_1080p_settings),
-		.pixel_rate = 178200000,
-		.link_freq_index = 0,
 	},
 	{
 		.width = 1280,
 		.height = 720,
 		.data = imx290_720p_settings,
 		.data_size = ARRAY_SIZE(imx290_720p_settings),
-		.pixel_rate = 178200000,
-		.link_freq_index = 0,
 	},
 };
 
@@ -442,6 +439,32 @@ static int imx290_get_fmt(struct v4l2_subdev *sd,
 	return 0;
 }
 
+static u8 imx290_get_link_freq_index(struct imx290 *imx290)
+{
+	const struct imx290_mode *cur_mode = imx290->current_mode;
+
+	return (cur_mode->width == 1920) ? 0 : 1;
+}
+
+static s64 imx290_get_link_freq(struct imx290 *imx290)
+{
+	u8 index = imx290_get_link_freq_index(imx290);
+
+	if (imx290->nlanes == 4)
+		return imx290_link_freq_4lanes[index];
+	else
+		return imx290_link_freq_2lanes[index];
+}
+
+static u64 imx290_calc_pixel_rate(struct imx290 *imx290)
+{
+	s64 link_freq = imx290_get_link_freq(imx290);
+	u8 nlanes = imx290->nlanes;
+
+	/* pixel rate = link_freq * 2 * nr_of_lanes / bits_per_sample */
+	return (link_freq * 2 * nlanes / 10);
+}
+
 static int imx290_set_fmt(struct v4l2_subdev *sd,
 			  struct v4l2_subdev_pad_config *cfg,
 		      struct v4l2_subdev_format *fmt)
@@ -475,10 +498,14 @@ static int imx290_set_fmt(struct v4l2_subdev *sd,
 		format = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
 	} else {
 		format = &imx290->current_format;
-		__v4l2_ctrl_s_ctrl(imx290->link_freq, mode->link_freq_index);
-		__v4l2_ctrl_s_ctrl_int64(imx290->pixel_rate, mode->pixel_rate);
-
 		imx290->current_mode = mode;
+
+		if (imx290->link_freq)
+			__v4l2_ctrl_s_ctrl(imx290->link_freq,
+					   imx290_get_link_freq_index(imx290));
+		if (imx290->pixel_rate)
+			__v4l2_ctrl_s_ctrl_int64(imx290->pixel_rate,
+						 imx290_calc_pixel_rate(imx290));
 	}
 
 	*format = fmt->format;
@@ -502,12 +529,11 @@ static int imx290_entity_init_cfg(struct v4l2_subdev *subdev,
 	return 0;
 }
 
-static int imx290_write_current_format(struct imx290 *imx290,
-				       struct v4l2_mbus_framefmt *format)
+static int imx290_write_current_format(struct imx290 *imx290)
 {
 	int ret;
 
-	switch (format->code) {
+	switch (imx290->current_format.code) {
 	case MEDIA_BUS_FMT_SRGGB10_1X10:
 		ret = imx290_set_register_array(imx290, imx290_10bit_settings,
 						ARRAY_SIZE(
@@ -558,8 +584,8 @@ static int imx290_start_streaming(struct imx290 *imx290)
 		return ret;
 	}
 
-	/* Set current frame format */
-	ret = imx290_write_current_format(imx290, &imx290->current_format);
+	/* Apply the register values related to current frame format */
+	ret = imx290_write_current_format(imx290);
 	if (ret < 0) {
 		dev_err(imx290->dev, "Could not set frame format\n");
 		return ret;
@@ -821,12 +847,6 @@ static int imx290_probe(struct i2c_client *client)
 		goto free_err;
 	}
 
-	if (imx290->ep.link_frequencies[0] != IMX290_DEFAULT_LINK_FREQ) {
-		dev_err(dev, "Unsupported link frequency\n");
-		ret = -EINVAL;
-		goto free_err;
-	}
-
 	/* Only CSI2 is supported for now */
 	if (imx290->ep.bus_type != V4L2_MBUS_CSI2_DPHY) {
 		dev_err(dev, "Unsupported bus type, should be CSI2\n");
@@ -879,23 +899,38 @@ static int imx290_probe(struct i2c_client *client)
 
 	mutex_init(&imx290->lock);
 
+	/*
+	 * Initialize the frame format. In particular, imx290->current_mode
+	 * and imx290->bpp are set to defaults: imx290_calc_pixel_rate() call
+	 * below relies on these fields.
+	 */
+	imx290_entity_init_cfg(&imx290->sd, NULL);
+
 	v4l2_ctrl_handler_init(&imx290->ctrls, 3);
 
 	v4l2_ctrl_new_std(&imx290->ctrls, &imx290_ctrl_ops,
 			  V4L2_CID_GAIN, 0, 72, 1, 0);
-	imx290->link_freq =
-		v4l2_ctrl_new_int_menu(&imx290->ctrls,
-				       &imx290_ctrl_ops,
-				       V4L2_CID_LINK_FREQ,
-				       ARRAY_SIZE(imx290_link_freq) - 1,
-				       0, imx290_link_freq);
+	if (imx290->nlanes == 4)
+		imx290->link_freq =
+			v4l2_ctrl_new_int_menu(&imx290->ctrls,
+					       &imx290_ctrl_ops,
+					       V4L2_CID_LINK_FREQ,
+					       ARRAY_SIZE(imx290_link_freq_4lanes) - 1,
+					       0, imx290_link_freq_4lanes);
+	else
+		imx290->link_freq =
+			v4l2_ctrl_new_int_menu(&imx290->ctrls,
+					       &imx290_ctrl_ops,
+					       V4L2_CID_LINK_FREQ,
+					       ARRAY_SIZE(imx290_link_freq_2lanes) - 1,
+					       0, imx290_link_freq_2lanes);
 	if (imx290->link_freq)
 		imx290->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
 
 	imx290->pixel_rate = v4l2_ctrl_new_std(&imx290->ctrls, &imx290_ctrl_ops,
 					       V4L2_CID_PIXEL_RATE, 1,
 					       INT_MAX, 1,
-					       imx290_modes[0].pixel_rate);
+					       imx290_calc_pixel_rate(imx290));
 
 	imx290->sd.ctrl_handler = &imx290->ctrls;
 
@@ -919,9 +954,6 @@ static int imx290_probe(struct i2c_client *client)
 		goto free_ctrl;
 	}
 
-	/* Initialize the frame format (this also sets imx290->current_mode) */
-	imx290_entity_init_cfg(&imx290->sd, NULL);
-
 	ret = v4l2_async_register_subdev(&imx290->sd);
 	if (ret < 0) {
 		dev_err(dev, "Could not register v4l2 device\n");
-- 
2.17.1