media: i2c: imx290: Add support for 74.25MHz external clock

The sensor supports either a 37.125 or 74.25MHz external, but
the driver only supported 37.125MHz.

Add the relevant register configuration for either clock
frequency option.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/i2c/imx290.c

@@ -105,6 +105,7 @@
 #define IMX290_TCLKPREPARE				IMX290_REG_16BIT(0x3452)
 #define IMX290_TLPX					IMX290_REG_16BIT(0x3454)
 #define IMX290_X_OUT_SIZE				IMX290_REG_16BIT(0x3472)
+#define IMX290_INCKSEL7					IMX290_REG_8BIT(0x3480)
 
 #define IMX290_PGCTRL_REGEN				BIT(0)
 #define IMX290_PGCTRL_THRU				BIT(1)
@@ -181,11 +182,29 @@ struct imx290_model_info {
 	enum imx290_colour_variant colour_variant;
 };
 
+enum imx290_clk_freq {
+	IMX290_CLK_37_125,
+	IMX290_CLK_74_25,
+	IMX290_NUM_CLK
+};
+
 struct imx290_regval {
 	u32 reg;
 	u32 val;
 };
 
+/*
+ * Clock configuration for registers INCKSEL1 to INCKSEL6.
+ */
+struct imx290_clk_cfg {
+	u8 incksel1;
+	u8 incksel2;
+	u8 incksel3;
+	u8 incksel4;
+	u8 incksel5;
+	u8 incksel6;
+};
+
 struct imx290_mode {
 	u32 width;
 	u32 height;
@@ -195,6 +214,8 @@ struct imx290_mode {
 
 	const struct imx290_regval *data;
 	u32 data_size;
+
+	const struct imx290_clk_cfg *clk_cfg;
 };
 
 struct imx290_csi_cfg {
@@ -213,6 +234,7 @@ struct imx290 {
 	struct device *dev;
 	struct clk *xclk;
 	struct regmap *regmap;
+	enum imx290_clk_freq xclk_idx;
 	u8 nlanes;
 	const struct imx290_model_info *model;
 
@@ -241,7 +263,6 @@ static inline struct imx290 *to_imx290(struct v4l2_subdev *_sd)
  */
 
 static const struct imx290_regval imx290_global_init_settings[] = {
-	{ IMX290_EXTCK_FREQ, 0x2520 },
 	{ IMX290_WINWV_OB, 12 },
 	{ IMX290_WINPH, 0 },
 	{ IMX290_WINPV, 0 },
@@ -291,7 +312,18 @@ static const struct imx290_regval imx290_global_init_settings[] = {
 	{ IMX290_REG_8BIT(0x33b0), 0x50 },
 	{ IMX290_REG_8BIT(0x33b2), 0x1a },
 	{ IMX290_REG_8BIT(0x33b3), 0x04 },
-	{ IMX290_REG_8BIT(0x3480), 0x49 },
+};
+
+#define IMX290_NUM_CLK_REGS	2
+static const struct imx290_regval xclk_regs[][IMX290_NUM_CLK_REGS] = {
+	[IMX290_CLK_37_125] = {
+		{ IMX290_EXTCK_FREQ, (37125 * 256) / 1000 },
+		{ IMX290_INCKSEL7, 0x49 },
+	},
+	[IMX290_CLK_74_25] = {
+		{ IMX290_EXTCK_FREQ, (74250 * 256) / 1000 },
+		{ IMX290_INCKSEL7, 0x92 },
+	},
 };
 
 static const struct imx290_regval imx290_1080p_settings[] = {
@@ -301,12 +333,6 @@ static const struct imx290_regval imx290_1080p_settings[] = {
 	{ IMX290_OPB_SIZE_V, 10 },
 	{ IMX290_X_OUT_SIZE, 1920 },
 	{ IMX290_Y_OUT_SIZE, 1080 },
-	{ IMX290_INCKSEL1, 0x18 },
-	{ IMX290_INCKSEL2, 0x03 },
-	{ IMX290_INCKSEL3, 0x20 },
-	{ IMX290_INCKSEL4, 0x01 },
-	{ IMX290_INCKSEL5, 0x1a },
-	{ IMX290_INCKSEL6, 0x1a },
 };
 
 static const struct imx290_regval imx290_720p_settings[] = {
@@ -316,12 +342,6 @@ static const struct imx290_regval imx290_720p_settings[] = {
 	{ IMX290_OPB_SIZE_V, 4 },
 	{ IMX290_X_OUT_SIZE, 1280 },
 	{ IMX290_Y_OUT_SIZE, 720 },
-	{ IMX290_INCKSEL1, 0x20 },
-	{ IMX290_INCKSEL2, 0x00 },
-	{ IMX290_INCKSEL3, 0x20 },
-	{ IMX290_INCKSEL4, 0x01 },
-	{ IMX290_INCKSEL5, 0x1a },
-	{ IMX290_INCKSEL6, 0x1a },
 };
 
 static const struct imx290_regval imx290_10bit_settings[] = {
@@ -427,6 +447,48 @@ static inline int imx290_link_freqs_num(const struct imx290 *imx290)
 		return ARRAY_SIZE(imx290_link_freq_4lanes);
 }
 
+static const struct imx290_clk_cfg imx290_1080p_clock_config[] = {
+	[IMX290_CLK_37_125] = {
+		/* 37.125MHz clock config */
+		.incksel1 = 0x18,
+		.incksel2 = 0x03,
+		.incksel3 = 0x20,
+		.incksel4 = 0x01,
+		.incksel5 = 0x1a,
+		.incksel6 = 0x1a,
+	},
+	[IMX290_CLK_74_25] = {
+		/* 74.25MHz clock config */
+		.incksel1 = 0x0c,
+		.incksel2 = 0x03,
+		.incksel3 = 0x10,
+		.incksel4 = 0x01,
+		.incksel5 = 0x1b,
+		.incksel6 = 0x1b,
+	},
+};
+
+static const struct imx290_clk_cfg imx290_720p_clock_config[] = {
+	[IMX290_CLK_37_125] = {
+		/* 37.125MHz clock config */
+		.incksel1 = 0x20,
+		.incksel2 = 0x00,
+		.incksel3 = 0x20,
+		.incksel4 = 0x01,
+		.incksel5 = 0x1a,
+		.incksel6 = 0x1a,
+	},
+	[IMX290_CLK_74_25] = {
+		/* 74.25MHz clock config */
+		.incksel1 = 0x10,
+		.incksel2 = 0x00,
+		.incksel3 = 0x10,
+		.incksel4 = 0x01,
+		.incksel5 = 0x1b,
+		.incksel6 = 0x1b,
+	},
+};
+
 /* Mode configs */
 static const struct imx290_mode imx290_modes_2lanes[] = {
 	{
@@ -437,6 +499,7 @@ static const struct imx290_mode imx290_modes_2lanes[] = {
 		.link_freq_index = FREQ_INDEX_1080P,
 		.data = imx290_1080p_settings,
 		.data_size = ARRAY_SIZE(imx290_1080p_settings),
+		.clk_cfg = imx290_1080p_clock_config,
 	},
 	{
 		.width = 1280,
@@ -446,6 +509,7 @@ static const struct imx290_mode imx290_modes_2lanes[] = {
 		.link_freq_index = FREQ_INDEX_720P,
 		.data = imx290_720p_settings,
 		.data_size = ARRAY_SIZE(imx290_720p_settings),
+		.clk_cfg = imx290_720p_clock_config,
 	},
 };
 
@@ -458,6 +522,7 @@ static const struct imx290_mode imx290_modes_4lanes[] = {
 		.link_freq_index = FREQ_INDEX_1080P,
 		.data = imx290_1080p_settings,
 		.data_size = ARRAY_SIZE(imx290_1080p_settings),
+		.clk_cfg = imx290_1080p_clock_config,
 	},
 	{
 		.width = 1280,
@@ -467,6 +532,7 @@ static const struct imx290_mode imx290_modes_4lanes[] = {
 		.link_freq_index = FREQ_INDEX_720P,
 		.data = imx290_720p_settings,
 		.data_size = ARRAY_SIZE(imx290_720p_settings),
+		.clk_cfg = imx290_720p_clock_config,
 	},
 };
 
@@ -592,6 +658,26 @@ static int imx290_set_register_array(struct imx290 *imx290,
 	return 0;
 }
 
+static int imx290_set_clock(struct imx290 *imx290)
+{
+	const struct imx290_mode *mode = imx290->current_mode;
+	enum imx290_clk_freq clk_idx = imx290->xclk_idx;
+	const struct imx290_clk_cfg *clk_cfg = &mode->clk_cfg[clk_idx];
+	int ret;
+
+	ret = imx290_set_register_array(imx290, xclk_regs[clk_idx],
+					IMX290_NUM_CLK_REGS);
+
+	imx290_write(imx290, IMX290_INCKSEL1, clk_cfg->incksel1, &ret);
+	imx290_write(imx290, IMX290_INCKSEL2, clk_cfg->incksel2, &ret);
+	imx290_write(imx290, IMX290_INCKSEL3, clk_cfg->incksel3, &ret);
+	imx290_write(imx290, IMX290_INCKSEL4, clk_cfg->incksel4, &ret);
+	imx290_write(imx290, IMX290_INCKSEL5, clk_cfg->incksel5, &ret);
+	imx290_write(imx290, IMX290_INCKSEL6, clk_cfg->incksel6, &ret);
+
+	return ret;
+}
+
 static int imx290_set_data_lanes(struct imx290 *imx290)
 {
 	int ret = 0;
@@ -896,6 +982,13 @@ static int imx290_start_streaming(struct imx290 *imx290,
 		return ret;
 	}
 
+	/* Set clock parameters based on mode and xclk */
+	ret = imx290_set_clock(imx290);
+	if (ret < 0) {
+		dev_err(imx290->dev, "Could not set clocks\n");
+		return ret;
+	}
+
 	/* Set data lane count */
 	ret = imx290_set_data_lanes(imx290);
 	if (ret < 0) {
@@ -1295,8 +1388,15 @@ static int imx290_init_clk(struct imx290 *imx290)
 		return ret;
 	}
 
-	/* external clock must be 37.125 MHz */
-	if (xclk_freq != 37125000) {
+	/* external clock must be 37.125 MHz or 74.25MHz */
+	switch (xclk_freq) {
+	case 37125000:
+		imx290->xclk_idx = IMX290_CLK_37_125;
+		break;
+	case 74250000:
+		imx290->xclk_idx = IMX290_CLK_74_25;
+		break;
+	default:
 		dev_err(imx290->dev, "External clock frequency %u is not supported\n",
 			xclk_freq);
 		return -EINVAL;