[SRU][N:linux-xilinx][PATCH 07/14] drivers: media: imx708: Increase usable link frequencies
Stewart Hore
stewart.hore at canonical.com
Wed Oct 15 00:26:02 UTC 2025
From: Naushir Patuck <naush at raspberrypi.com>
Add support for three different usable link frequencies (default 450Mhz,
447Mhz, and 453MHz) for the IMX708 camera sensor. The choice of
frequency is handled thorugh the "link-frequency" overlay parameter.
Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
(cherry picked from commit 3e39ce6319149d28a8f27a9331414fb7d151d519 rpi-6.6.y)
Signed-off-by: Juerg Haefliger <juerg.haefliger at canonical.com>
(cherry picked from commit 860e69ee8341b718d16fba45b272b03f5134b1b9 noble:linux-raspi)
Signed-off-by: Stewart Hore <stewart.hore at canonical.com>
---
drivers/media/i2c/imx708.c | 94 +++++++++++++++++++++++++++++++-------
1 file changed, 78 insertions(+), 16 deletions(-)
diff --git a/drivers/media/i2c/imx708.c b/drivers/media/i2c/imx708.c
index f046d896bc78..170a212f4316 100644
--- a/drivers/media/i2c/imx708.c
+++ b/drivers/media/i2c/imx708.c
@@ -35,8 +35,6 @@
#define IMX708_XCLK_FREQ 24000000
-#define IMX708_DEFAULT_LINK_FREQ 450000000
-
/* Default initial pixel rate, will get updated for each mode. */
#define IMX708_INITIAL_PIXEL_RATE 590000000
@@ -181,6 +179,50 @@ static const u8 pdaf_gains[2][9] = {
{ 0x35, 0x35, 0x35, 0x38, 0x3e, 0x46, 0x4c, 0x4c, 0x4c }
};
+/* Link frequency setup */
+enum {
+ IMX708_LINK_FREQ_450MHZ,
+ IMX708_LINK_FREQ_447MHZ,
+ IMX708_LINK_FREQ_453MHZ,
+};
+
+static const s64 link_freqs[] = {
+ [IMX708_LINK_FREQ_450MHZ] = 450000000,
+ [IMX708_LINK_FREQ_447MHZ] = 447000000,
+ [IMX708_LINK_FREQ_453MHZ] = 453000000,
+};
+
+/* 450MHz is the nominal "default" link frequency */
+static const struct imx708_reg link_450Mhz_regs[] = {
+ {0x030E, 0x01},
+ {0x030F, 0x2c},
+};
+
+static const struct imx708_reg link_447Mhz_regs[] = {
+ {0x030E, 0x01},
+ {0x030F, 0x2a},
+};
+
+static const struct imx708_reg link_453Mhz_regs[] = {
+ {0x030E, 0x01},
+ {0x030F, 0x2e},
+};
+
+static const struct imx708_reg_list link_freq_regs[] = {
+ [IMX708_LINK_FREQ_450MHZ] = {
+ .regs = link_450Mhz_regs,
+ .num_of_regs = ARRAY_SIZE(link_450Mhz_regs)
+ },
+ [IMX708_LINK_FREQ_447MHZ] = {
+ .regs = link_447Mhz_regs,
+ .num_of_regs = ARRAY_SIZE(link_447Mhz_regs)
+ },
+ [IMX708_LINK_FREQ_453MHZ] = {
+ .regs = link_453Mhz_regs,
+ .num_of_regs = ARRAY_SIZE(link_453Mhz_regs)
+ },
+};
+
static const struct imx708_reg mode_common_regs[] = {
{0x0100, 0x00},
{0x0136, 0x18},
@@ -278,8 +320,6 @@ static const struct imx708_reg mode_4608x2592_regs[] = {
{0x0307, 0x7C},
{0x030B, 0x02},
{0x030D, 0x04},
- {0x030E, 0x01},
- {0x030F, 0x2C},
{0x0310, 0x01},
{0x3CA0, 0x00},
{0x3CA1, 0x64},
@@ -376,8 +416,6 @@ static const struct imx708_reg mode_2x2binned_regs[] = {
{0x0307, 0x7A},
{0x030B, 0x02},
{0x030D, 0x04},
- {0x030E, 0x01},
- {0x030F, 0x2C},
{0x0310, 0x01},
{0x3CA0, 0x00},
{0x3CA1, 0x3C},
@@ -472,8 +510,6 @@ static const struct imx708_reg mode_2x2binned_720p_regs[] = {
{0x0307, 0x76},
{0x030B, 0x02},
{0x030D, 0x04},
- {0x030E, 0x01},
- {0x030F, 0x2C},
{0x0310, 0x01},
{0x3CA0, 0x00},
{0x3CA1, 0x3C},
@@ -568,8 +604,6 @@ static const struct imx708_reg mode_hdr_regs[] = {
{0x0307, 0xA2},
{0x030B, 0x02},
{0x030D, 0x04},
- {0x030E, 0x01},
- {0x030F, 0x2C},
{0x0310, 0x01},
{0x3CA0, 0x00},
{0x3CA1, 0x00},
@@ -795,6 +829,7 @@ struct imx708 {
struct v4l2_ctrl *blue_balance;
struct v4l2_ctrl *notify_gains;
struct v4l2_ctrl *hdr_mode;
+ struct v4l2_ctrl *link_freq;
/* Current mode */
const struct imx708_mode *mode;
@@ -813,6 +848,8 @@ struct imx708 {
/* Current long exposure factor in use. Set through V4L2_CID_VBLANK */
unsigned int long_exp_shift;
+
+ unsigned int link_freq_idx;
};
static inline struct imx708 *to_imx708(struct v4l2_subdev *_sd)
@@ -1428,7 +1465,7 @@ static int imx708_get_selection(struct v4l2_subdev *sd,
static int imx708_start_streaming(struct imx708 *imx708)
{
struct i2c_client *client = v4l2_get_subdevdata(&imx708->sd);
- const struct imx708_reg_list *reg_list;
+ const struct imx708_reg_list *reg_list, *freq_regs;
int i, ret;
u32 val;
@@ -1474,6 +1511,16 @@ static int imx708_start_streaming(struct imx708 *imx708)
return ret;
}
+ /* Update the link frequency registers */
+ freq_regs = &link_freq_regs[imx708->link_freq_idx];
+ ret = imx708_write_regs(imx708, freq_regs->regs,
+ freq_regs->num_of_regs);
+ if (ret) {
+ dev_err(&client->dev, "%s failed to set link frequency registers\n",
+ __func__);
+ return ret;
+ }
+
/* Apply customized values from user */
ret = __v4l2_ctrl_handler_setup(imx708->sd.ctrl_handler);
if (ret)
@@ -1720,6 +1767,7 @@ static int imx708_init_controls(struct imx708 *imx708)
struct v4l2_ctrl_handler *ctrl_hdlr;
struct i2c_client *client = v4l2_get_subdevdata(&imx708->sd);
struct v4l2_fwnode_device_properties props;
+ struct v4l2_ctrl *ctrl;
unsigned int i;
int ret;
@@ -1738,6 +1786,12 @@ static int imx708_init_controls(struct imx708 *imx708)
IMX708_INITIAL_PIXEL_RATE, 1,
IMX708_INITIAL_PIXEL_RATE);
+ ctrl = v4l2_ctrl_new_int_menu(ctrl_hdlr, &imx708_ctrl_ops,
+ V4L2_CID_LINK_FREQ, 0, 0,
+ &link_freqs[imx708->link_freq_idx]);
+ if (ctrl)
+ ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
+
/*
* Create the controls here, but mode specific limits are setup
* in the imx708_set_framing_limits() call below.
@@ -1833,13 +1887,14 @@ static void imx708_free_controls(struct imx708 *imx708)
mutex_destroy(&imx708->mutex);
}
-static int imx708_check_hwcfg(struct device *dev)
+static int imx708_check_hwcfg(struct device *dev, struct imx708 *imx708)
{
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) {
@@ -1864,11 +1919,18 @@ static int imx708_check_hwcfg(struct device *dev)
goto error_out;
}
- if (ep_cfg.nr_of_link_frequencies != 1 ||
- ep_cfg.link_frequencies[0] != IMX708_DEFAULT_LINK_FREQ) {
+ for (i = 0; i < ARRAY_SIZE(link_freqs); i++) {
+ if (link_freqs[i] == ep_cfg.link_frequencies[0]) {
+ imx708->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;
@@ -1893,7 +1955,7 @@ static int imx708_probe(struct i2c_client *client)
v4l2_i2c_subdev_init(&imx708->sd, client, &imx708_subdev_ops);
/* Check the hardware configuration in device tree */
- if (imx708_check_hwcfg(dev))
+ if (imx708_check_hwcfg(dev, imx708))
return -EINVAL;
/* Get system clock (xclk) */
--
2.48.1
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