From 7c3aad6fbaff06694a77b46ec8600bee6c0b7f42 Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Wed, 15 Jul 2026 12:43:32 +0100 Subject: [PATCH] media: imx355: Support 2 lane readout The sensor supports 2 or 4 lane readout, but the driver only allowed for 4 lanes. Add 2 lane support. The clock tree only supports single PLL mode to feed both IOP (MIPI) and IVT (Pixel array). 2 lane mode supports a MIPI link frequency of up to 445MHz (890Mbit/s) cf 360MHz (720Mbit/s) for 4lane. Update clock setup and pixel rates to match. Signed-off-by: Dave Stevenson Signed-off-by: Sakari Ailus --- drivers/media/i2c/imx355.c | 67 +++++++++++++++++++++++++++----------- 1 file changed, 48 insertions(+), 19 deletions(-) diff --git a/drivers/media/i2c/imx355.c b/drivers/media/i2c/imx355.c index d8f8efc0c927..0462e0feee36 100644 --- a/drivers/media/i2c/imx355.c +++ b/drivers/media/i2c/imx355.c @@ -27,11 +27,14 @@ #define IMX355_REG_CHIP_ID CCI_REG16(0x0016) #define IMX355_CHIP_ID 0x0355 +#define IMX355_REG_LANE_SEL CCI_REG8(0x0114) + /* PLL registers that depend on the external clock frequency */ #define IMX355_REG_EXTCLK_FREQ CCI_REG16(0x0136) #define IMX355_REG_PLL_OP_PREDIV CCI_REG8(0x030d) #define IMX355_REG_PLL_OP_MUL CCI_REG16(0x030e) #define IMX355_REG_PLL_IVT_PCK_DIV CCI_REG8(0x0301) +#define IMX355_REG_PLL_IVT_SYSCK_DIV CCI_REG8(0x0303) #define IMX355_PLL_OP_PREDIV 2 #define IMX355_PLL_IVT_PCK_DIV 5 @@ -80,6 +83,8 @@ #define IMX355_TEST_PATTERN_GRAY_COLOR_BARS 3 #define IMX355_TEST_PATTERN_PN9 4 +#define IMX355_REG_REQ_LINK_BIT_RATE CCI_REG16(0x0820) + #define IMX355_REG_BINNING_MODE CCI_REG8(0x0900) #define IMX355_REG_BINNING_TYPE CCI_REG8(0x0901) #define IMX355_REG_BINNING_WEIGHTING CCI_REG8(0x0902) @@ -87,9 +92,6 @@ /* Flip Control */ #define IMX355_REG_ORIENTATION CCI_REG8(0x0101) -/* number of data lanes */ -#define IMX355_DATA_LANES 4 - #define IMX355_PIXEL_ARRAY_TOP 0 #define IMX355_PIXEL_ARRAY_LEFT 0 #define IMX355_PIXEL_ARRAY_WIDTH 3280 @@ -120,30 +122,38 @@ struct imx355_mode { struct imx355_clk_params { u32 ext_clk; - u16 extclk_freq; /* External clock (MHz) in 8.8 fixed point) */ - u16 pll_op_mpy; /* OP system PLL multiplier */ + u16 extclk_freq; /* External clock (MHz) in 8.8 fixed point) */ + u16 pll_op_mpy[2]; /* OP system PLL multiplier */ + u8 pll_op_prediv[2]; /* OP system pre PLL d */ }; /* * The clock tree is in single PLL mode, so PREDIV_VT and MPY_IVT do nothing. - * All modes use the same PLL setup for OP, with IOPCK being 720MHz. + * In 4 lane mode the MIPI rate is 360Mhz (720Mbit/s) and pixel rate is + * 288MPix/s. + * In 2 lane mode the MIPI rate is 444MHz (888Mbit/s) and pixel rate + * 177.6MPix/s with a 24MHz clock, and 441.6MHz (883.2Mbit/s) and 176.6MPix/s + * with a 19.2MHz clock. */ static const struct imx355_clk_params imx355_clk_params[] = { { .ext_clk = 19200000, - .extclk_freq = 0x1333, /* 19.2 MHz */ - .pll_op_mpy = 75, /* 19.2 / 2 * 75 = 720 MHz */ + .extclk_freq = 0x1333, + .pll_op_mpy = { 75, 92 }, + .pll_op_prediv = { 2, 2 } }, { .ext_clk = 24000000, - .extclk_freq = 0x1800, /* 24.0 MHz */ - .pll_op_mpy = 60, /* 24.0 / 2 * 60 = 720 MHz */ + .extclk_freq = 0x1800, + .pll_op_mpy = { 60, 111 }, + .pll_op_prediv = { 2, 3 } }, }; struct imx355_hwcfg { s64 link_freq_menu; unsigned long link_freq_bitmap; + unsigned int num_lanes; }; struct imx355 { @@ -239,7 +249,6 @@ static const struct cci_reg_sequence imx355_global_regs[] = { { CCI_REG8(0x305a), 0x00 }, { CCI_REG8(0x0112), 0x0a }, { CCI_REG8(0x0113), 0x0a }, - { CCI_REG8(0x0114), 0x03 }, { IMX355_REG_PLL_IVT_PCK_DIV, IMX355_PLL_IVT_PCK_DIV }, { CCI_REG8(0x0303), 0x01 }, { CCI_REG8(0x0305), 0x02 }, @@ -250,8 +259,6 @@ static const struct cci_reg_sequence imx355_global_regs[] = { { CCI_REG8(0x0310), 0x00 }, { CCI_REG8(0x0220), 0x00 }, { CCI_REG8(0x0222), 0x01 }, - { CCI_REG8(0x0820), 0x0b }, - { CCI_REG8(0x0821), 0x40 }, { CCI_REG8(0x3088), 0x04 }, { CCI_REG8(0x6813), 0x02 }, { CCI_REG8(0x6835), 0x07 }, @@ -817,6 +824,7 @@ imx355_set_pad_format(struct v4l2_subdev *sd, __v4l2_ctrl_modify_range(imx355->vblank, IMX355_VBLANK_MIN, height, 1, vblank_def); __v4l2_ctrl_s_ctrl(imx355->vblank, vblank_def); + h_blank = mode->llp - imx355->cur_mode->width; /* * Currently hblank is not changeable. @@ -880,6 +888,8 @@ static int imx355_start_streaming(struct imx355 *imx355) { const struct imx355_reg_list *reg_list; const struct imx355_mode *mode; + int lane_idx = imx355->hwcfg->num_lanes == 4 ? 0 : 1; + u64 link_bitrate; u8 binning_mode; int ret = 0; @@ -915,7 +925,21 @@ static int imx355_start_streaming(struct imx355 *imx355) cci_write(imx355->regmap, IMX355_REG_EXTCLK_FREQ, imx355->clk_params->extclk_freq, &ret); cci_write(imx355->regmap, IMX355_REG_PLL_OP_MUL, - imx355->clk_params->pll_op_mpy, &ret); + imx355->clk_params->pll_op_mpy[lane_idx], &ret); + cci_write(imx355->regmap, IMX355_REG_PLL_OP_PREDIV, + imx355->clk_params->pll_op_prediv[lane_idx], &ret); + cci_write(imx355->regmap, IMX355_REG_PLL_IVT_SYSCK_DIV, + lane_idx ? 2 : 1, &ret); + + /* Set MIPI configuration */ + cci_write(imx355->regmap, IMX355_REG_LANE_SEL, + imx355->hwcfg->num_lanes - 1, &ret); + + link_bitrate = imx355->link_freq->qmenu_int[imx355->link_freq->val] * + imx355->hwcfg->num_lanes * 2; + do_div(link_bitrate, 1000000); + cci_write(imx355->regmap, IMX355_REG_REQ_LINK_BIT_RATE, link_bitrate, + &ret); /* set digital gain control to all color mode */ cci_write(imx355->regmap, IMX355_REG_DPGA_USE_GLOBAL_GAIN, 1, &ret); @@ -1101,9 +1125,9 @@ static int imx355_init_controls(struct imx355 *imx355) imx355->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY; /* pixel_rate = link_freq * 2 * nr_of_lanes / bits_per_sample */ - pixel_rate = imx355->hwcfg->link_freq_menu * 2 * 4; + pixel_rate = imx355->hwcfg->link_freq_menu * 2 * imx355->hwcfg->num_lanes; do_div(pixel_rate, 10); - /* By default, PIXEL_RATE is read only */ + v4l2_ctrl_new_std(ctrl_hdlr, &imx355_ctrl_ops, V4L2_CID_PIXEL_RATE, pixel_rate, pixel_rate, 1, pixel_rate); @@ -1186,6 +1210,7 @@ static struct imx355_hwcfg *imx355_get_hwcfg(struct imx355 *imx355) const struct imx355_clk_params *clk = imx355->clk_params; struct fwnode_handle *ep; struct fwnode_handle *fwnode = dev_fwnode(dev); + int lane_idx; int ret; if (!fwnode) @@ -1203,11 +1228,15 @@ static struct imx355_hwcfg *imx355_get_hwcfg(struct imx355 *imx355) if (!cfg) goto out_err; - if (bus_cfg.bus.mipi_csi2.num_data_lanes != IMX355_DATA_LANES) + if (bus_cfg.bus.mipi_csi2.num_data_lanes != 2 && + bus_cfg.bus.mipi_csi2.num_data_lanes != 4) goto out_err; - cfg->link_freq_menu = (clk->ext_clk * clk->pll_op_mpy) / - (IMX355_PLL_OP_PREDIV * 2); + cfg->num_lanes = bus_cfg.bus.mipi_csi2.num_data_lanes; + + lane_idx = cfg->num_lanes == 4 ? 0 : 1; + cfg->link_freq_menu = (clk->ext_clk * clk->pll_op_mpy[lane_idx]) / + (clk->pll_op_prediv[lane_idx] * 2); ret = v4l2_link_freq_to_bitmap(dev, bus_cfg.link_frequencies, bus_cfg.nr_of_link_frequencies, &cfg->link_freq_menu, 1,