Hi Laurent,
On 15/06/2020 00:59, Laurent Pinchart wrote:
> The external pixel rate is retrieved when starting the camerarx and only
> used then. There's no need to store it in the cal_camerarx structure, it
> can be returned by cal_camerarx_get_external_info() and explicitly
> passed to cal_camerarx_config().
>
> While at it, rename cal_camerarx_get_external_info() to
> cal_camerarx_get_external_rate() to better reflect the function's
> purpose.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/platform/ti-vpe/cal.c | 24 ++++++++++++------------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c
> index 8326db0e4197..a11457909134 100644
> --- a/drivers/media/platform/ti-vpe/cal.c
> +++ b/drivers/media/platform/ti-vpe/cal.c
> @@ -272,7 +272,6 @@ struct cal_camerarx {
> struct v4l2_fwnode_endpoint endpoint;
> struct device_node *sensor_node;
> struct v4l2_subdev *sensor;
> - unsigned int external_rate;
Here, external_rate is 32 bit,
> };
>
> struct cal_dev {
> @@ -481,9 +480,10 @@ static void cal_quickdump_regs(struct cal_dev *cal)
> * ------------------------------------------------------------------
> */
>
> -static int cal_camerarx_get_external_info(struct cal_camerarx *phy)
> +static s64 cal_camerarx_get_external_rate(struct cal_camerarx *phy)
> {
> struct v4l2_ctrl *ctrl;
> + s64 rate;
and now it becomes a 64 bit value.
>
> if (!phy->sensor)
> return -ENODEV;
> @@ -495,10 +495,10 @@ static int cal_camerarx_get_external_info(struct cal_camerarx *phy)
> return -EPIPE;
> }
>
> - phy->external_rate = v4l2_ctrl_g_ctrl_int64(ctrl);
> - phy_dbg(3, phy, "sensor Pixel Rate: %u\n", phy->external_rate);
> + rate = v4l2_ctrl_g_ctrl_int64(ctrl);
> + phy_dbg(3, phy, "sensor Pixel Rate: %llu\n", rate);
>
> - return 0;
> + return rate;
> }
>
> static void cal_camerarx_lane_config(struct cal_camerarx *phy)
> @@ -554,7 +554,7 @@ static void cal_camerarx_disable(struct cal_camerarx *phy)
> #define TCLK_MISS 1
> #define TCLK_SETTLE 14
>
> -static void cal_camerarx_config(struct cal_camerarx *phy,
> +static void cal_camerarx_config(struct cal_camerarx *phy, s64 external_rate,
> const struct cal_fmt *fmt)
> {
> unsigned int reg0, reg1;
> @@ -566,7 +566,7 @@ static void cal_camerarx_config(struct cal_camerarx *phy,
>
> /* DPHY timing configuration */
> /* CSI-2 is DDR and we only count used lanes. */
> - csi2_ddrclk_khz = phy->external_rate / 1000
> + csi2_ddrclk_khz = external_rate / 1000
> / (2 * num_lanes) * fmt->bpp;
Which causes this calculation to fail on 32 bit ARM builds.
(I'm building for the DRA76-EVM).
I've got the following fix up on the top of your tree to solve this, but
I'm not particularly happy about having to break the calculation up (and
re-use external_rate) though the use of do_div.
>From ca6ce335a852e34364bc45cb4240f703e4ea4248 Mon Sep 17 00:00:00 2001
From: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
Date: Tue, 16 Jun 2020 16:19:04 +0100
Subject: [PATCH] media: ti-vpe: cal: Use do_div() for 64 bit operations
Support building the CAL driver on arm32 bit targets by updating the
CSI2 clock calculation (which uses a signed 64 bit input value from
the sensors pixel clock rate) to use the do_div() helpers.
The calculation is split into distinct parts to maintain
order of operations while making use of the do_div macro and further
re-ordered to convert to kHz at the end to maintain precision.
Signed-off-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
---
drivers/media/platform/ti-vpe/cal-camerarx.c | 22 +++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/media/platform/ti-vpe/cal-camerarx.c
b/drivers/media/platform/ti-vpe/cal-camerarx.c
index 014ca46509db..0ef19a516902 100644
--- a/drivers/media/platform/ti-vpe/cal-camerarx.c
+++ b/drivers/media/platform/ti-vpe/cal-camerarx.c
@@ -126,9 +126,25 @@ static void cal_camerarx_config(struct cal_camerarx
*phy, s64 external_rate)
u32 num_lanes = mipi_csi2->num_data_lanes;
/* DPHY timing configuration */
- /* CSI-2 is DDR and we only count used lanes. */
- csi2_ddrclk_khz = external_rate / 1000
- / (2 * num_lanes) * phy->fmtinfo->bpp;
+
+ /*
+ * CSI-2 is DDR and we only count used lanes.
+ *
+ * csi2_ddrclk_khz = external_rate / 1000
+ * / (2 * num_lanes) * phy->fmtinfo->bpp;
+ *
+ * The equation is broken into separate statements to maintain
+ * order of operations, and conversion to kHz is done last to
+ * keep precision.
+ *
+ * The 64 bit external_rate is modified during this equation and
+ * contains the result, not the original after calculation.
+ */
+ do_div(external_rate, 2 * num_lanes);
+ external_rate *= phy->fmtinfo->bpp;
+ do_div(external_rate, 1000);
+ csi2_ddrclk_khz = external_rate;
+
phy_dbg(1, phy, "csi2_ddrclk_khz: %d\n", csi2_ddrclk_khz);
/* THS_TERM: Programmed value = floor(20 ns/DDRClk period) */
--
2.25.1
If you have a better way to correctly calculate the rate (also noting
that I moved the /1000 to the end, I'm not sure if that's more correct,
or makes it stop following what the hardware would do) - please update
accordingly, or feel free to squash this patch in as you wish.
With the calculation corrected:
Reviewed-by: Kieran Bingham <kieran.bingham@xxxxxxxxxxxxxxxx>
--
Kieran
> phy_dbg(1, phy, "csi2_ddrclk_khz: %d\n", csi2_ddrclk_khz);
>
> @@ -667,13 +667,14 @@ static void cal_camerarx_wait_stop_state(struct cal_camerarx *phy)
> static int cal_camerarx_start(struct cal_camerarx *phy,
> const struct cal_fmt *fmt)
> {
> + s64 external_rate;
> u32 sscounter;
> u32 val;
> int ret;
>
> - ret = cal_camerarx_get_external_info(phy);
> - if (ret < 0)
> - return ret;
> + external_rate = cal_camerarx_get_external_rate(phy);
> + if (external_rate < 0)
> + return external_rate;
>
> ret = v4l2_subdev_call(phy->sensor, core, s_power, 1);
> if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV) {
> @@ -719,7 +720,7 @@ static int cal_camerarx_start(struct cal_camerarx *phy,
> reg_read(phy, CAL_CSI2_PHY_REG0);
>
> /* Program the PHY timing parameters. */
> - cal_camerarx_config(phy, fmt);
> + cal_camerarx_config(phy, external_rate, fmt);
>
> /*
> * b. Assert the FORCERXMODE signal.
> @@ -1034,7 +1035,6 @@ static struct cal_camerarx *cal_camerarx_create(struct cal_dev *cal,
>
> phy->cal = cal;
> phy->instance = instance;
> - phy->external_rate = 192000000;
>
> phy->res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> (instance == 0) ?
>
--
Regards
--
Kieran
