[PATCH v2 17/20] media: imx355: Compute link frequency from PLL setup
From: Dave Stevenson
Date: Tue Jul 07 2026 - 13:09:27 EST
In preparation for additional options in the PLL setup, compute
the link frequency rather than using a hardcoded value.
Signed-off-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx>
---
drivers/media/i2c/imx355.c | 41 ++++++++++++++++++-----------------------
1 file changed, 18 insertions(+), 23 deletions(-)
diff --git a/drivers/media/i2c/imx355.c b/drivers/media/i2c/imx355.c
index cff87c6ea789..3586c4cd3fbe 100644
--- a/drivers/media/i2c/imx355.c
+++ b/drivers/media/i2c/imx355.c
@@ -29,7 +29,11 @@
/* 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_PLL_OP_PREDIV 2
+#define IMX355_PLL_IVT_PCK_DIV 5
/* V_TIMING internal */
#define IMX355_REG_FLL CCI_REG16(0x0340)
@@ -83,9 +87,6 @@
/* Flip Control */
#define IMX355_REG_ORIENTATION CCI_REG8(0x0101)
-/* default link frequency and external clock */
-#define IMX355_LINK_FREQ_DEFAULT 360000000LL
-
/* number of data lanes */
#define IMX355_DATA_LANES 4
@@ -141,6 +142,7 @@ static const struct imx355_clk_params imx355_clk_params[] = {
};
struct imx355_hwcfg {
+ s64 link_freq_menu;
unsigned long link_freq_bitmap;
};
@@ -238,12 +240,12 @@ static const struct cci_reg_sequence imx355_global_regs[] = {
{ CCI_REG8(0x0112), 0x0a },
{ CCI_REG8(0x0113), 0x0a },
{ CCI_REG8(0x0114), 0x03 },
- { CCI_REG8(0x0301), 0x05 },
+ { IMX355_REG_PLL_IVT_PCK_DIV, IMX355_PLL_IVT_PCK_DIV },
{ CCI_REG8(0x0303), 0x01 },
- { CCI_REG8(0x0305), 0x00 },
+ { CCI_REG8(0x0305), 0x02 },
{ CCI_REG8(0x0306), 0x78 },
{ CCI_REG8(0x0307), 0x02 },
- { CCI_REG8(0x030d), 0x02 },
+ { IMX355_REG_PLL_OP_PREDIV, IMX355_PLL_OP_PREDIV },
{ CCI_REG8(0x0310), 0x00 },
{ CCI_REG8(0x0220), 0x00 },
{ CCI_REG8(0x0222), 0x01 },
@@ -337,14 +339,6 @@ static const char * const imx355_test_pattern_menu[] = {
"Pseudorandom Sequence (PN9)",
};
-/*
- * When adding more than the one below, make sure the disallowed ones will
- * actually be disabled in the LINK_FREQ control.
- */
-static const s64 link_freq_menu_items[] = {
- IMX355_LINK_FREQ_DEFAULT,
-};
-
/* Mode configs */
static const struct imx355_mode supported_modes[] = {
{
@@ -1080,7 +1074,6 @@ static int imx355_init_controls(struct imx355 *imx355)
s64 hblank;
u64 pixel_rate;
const struct imx355_mode *mode;
- u32 max;
int ret;
ctrl_hdlr = &imx355->ctrl_handler;
@@ -1089,15 +1082,14 @@ static int imx355_init_controls(struct imx355 *imx355)
return ret;
ctrl_hdlr->lock = &imx355->mutex;
- max = ARRAY_SIZE(link_freq_menu_items) - 1;
imx355->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr, &imx355_ctrl_ops,
- V4L2_CID_LINK_FREQ, max, 0,
- link_freq_menu_items);
+ V4L2_CID_LINK_FREQ, 0, 0,
+ &imx355->hwcfg->link_freq_menu);
if (imx355->link_freq)
imx355->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
/* pixel_rate = link_freq * 2 * nr_of_lanes / bits_per_sample */
- pixel_rate = IMX355_LINK_FREQ_DEFAULT * 2 * 4;
+ pixel_rate = imx355->hwcfg->link_freq_menu * 2 * 4;
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,
@@ -1172,12 +1164,14 @@ static int imx355_init_controls(struct imx355 *imx355)
return ret;
}
-static struct imx355_hwcfg *imx355_get_hwcfg(struct device *dev)
+static struct imx355_hwcfg *imx355_get_hwcfg(struct imx355 *imx355)
{
+ struct device *dev = imx355->dev;
struct imx355_hwcfg *cfg;
struct v4l2_fwnode_endpoint bus_cfg = {
.bus_type = V4L2_MBUS_CSI2_DPHY
};
+ const struct imx355_clk_params *clk = imx355->clk_params;
struct fwnode_handle *ep;
struct fwnode_handle *fwnode = dev_fwnode(dev);
int ret;
@@ -1200,10 +1194,11 @@ static struct imx355_hwcfg *imx355_get_hwcfg(struct device *dev)
if (bus_cfg.bus.mipi_csi2.num_data_lanes != IMX355_DATA_LANES)
goto out_err;
+ cfg->link_freq_menu = (clk->ext_clk * clk->pll_op_mpy) /
+ (IMX355_PLL_OP_PREDIV * 2);
ret = v4l2_link_freq_to_bitmap(dev, bus_cfg.link_frequencies,
bus_cfg.nr_of_link_frequencies,
- link_freq_menu_items,
- ARRAY_SIZE(link_freq_menu_items),
+ &cfg->link_freq_menu, 1,
&cfg->link_freq_bitmap);
if (ret)
goto out_err;
@@ -1275,7 +1270,7 @@ static int imx355_probe(struct i2c_client *client)
/* Initialize subdev */
v4l2_i2c_subdev_init(&imx355->sd, client, &imx355_subdev_ops);
- imx355->hwcfg = imx355_get_hwcfg(imx355->dev);
+ imx355->hwcfg = imx355_get_hwcfg(imx355);
if (!imx355->hwcfg) {
dev_err(imx355->dev, "failed to get hwcfg");
ret = -ENODEV;
--
2.34.1