media: camss: use v4l2_get_link_freq() to calculate the relevant clocks

There are places in the camss driver where camss_get_pixel_clock() is
called to get the pixel rate (using V4L2_CID_PIXEL_RATE control) and to
calculate the link frequency from it. There is a case when this would
not work: when V4L2_CID_PIXEL_RATE gets the rate at which the pixels are
read (sampled) from the sensor's pixel array, and this rate is different
from the pixel transmission rate over the CSI link, the link frequency
value can't be calculated from the pixel rate. One needs to use
V4L2_CID_LINK_FREQ to get the link frequency in this case.

Replace such calls to camss_get_pixel_clock() with calls to a wrapper
around v4l2_get_link_freq(). v4l2_get_link_freq() tries V4L2_CID_LINK_FREQ
first, and if it is not implemented by the camera sensor driver, falls
back to V4L2_CID_PIXEL_RATE to calculate the link frequency value from.

Calls to camss_get_pixel_clock() from vfe_[check,set]_clock_rates()
are left intact as it looks like this VFE clock does depend on the
rate the pixel samples comes out of the camera sensor, not on the
frequency at which the link between the sensor and the CSI receiver
operates.

Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Acked-by: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/platform/qcom/camss/camss-csid.c b/drivers/media/platform/qcom/camss/camss-csid.c
index be3fe76f3dc30bf2b6099c9f42350eb576a30690..cff9759c9158018b8a36d037cd94a6259a843454 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss-csid.c
+++ b/drivers/media/platform/qcom/camss/camss-csid.c
@@ -462,13 +462,17 @@ static irqreturn_t csid_isr(int irq, void *dev)
 static int csid_set_clock_rates(struct csid_device *csid)
 {
        struct device *dev = csid->camss->dev;
-       u32 pixel_clock;
+       const struct csid_format *fmt;
+       s64 link_freq;
        int i, j;
        int ret;
 
-       ret = camss_get_pixel_clock(&csid->subdev.entity, &pixel_clock);
-       if (ret)
-               pixel_clock = 0;
+       fmt = csid_get_fmt_entry(csid->formats, csid->nformats,
+                                csid->fmt[MSM_CSIPHY_PAD_SINK].code);
+       link_freq = camss_get_link_freq(&csid->subdev.entity, fmt->bpp,
+                                       csid->phy.lane_cnt);
+       if (link_freq < 0)
+               link_freq = 0;
 
        for (i = 0; i < csid->nclocks; i++) {
                struct camss_clock *clock = &csid->clock[i];
@@ -477,13 +481,7 @@ static int csid_set_clock_rates(struct csid_device *csid)
                    !strcmp(clock->name, "csi1") ||
                    !strcmp(clock->name, "csi2") ||
                    !strcmp(clock->name, "csi3")) {
-                       const struct csid_format *f = csid_get_fmt_entry(
-                               csid->formats,
-                               csid->nformats,
-                               csid->fmt[MSM_CSIPHY_PAD_SINK].code);
-                       u8 num_lanes = csid->phy.lane_cnt;
-                       u64 min_rate = pixel_clock * f->bpp /
-                                                       (2 * num_lanes * 4);
+                       u64 min_rate = link_freq / 4;
                        long rate;
 
                        camss_add_clock_margin(&min_rate);

diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c
index 12bce391d71fd0393d63413f52b114bb516fa1dd..30b454c369ab729677b5ba5bf0360f9cbb2e41b1 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c
+++ b/drivers/media/platform/qcom/camss/camss-csiphy-2ph-1-0.c
@@ -51,16 +51,13 @@ static void csiphy_reset(struct csiphy_device *csiphy)
  *
  * Helper function to calculate settle count value. This is
  * based on the CSI2 T_hs_settle parameter which in turn
- * is calculated based on the CSI2 transmitter pixel clock
- * frequency.
+ * is calculated based on the CSI2 transmitter link frequency.
  *
- * Return settle count value or 0 if the CSI2 pixel clock
- * frequency is not available
+ * Return settle count value or 0 if the CSI2 link frequency
+ * is not available
  */
-static u8 csiphy_settle_cnt_calc(u32 pixel_clock, u8 bpp, u8 num_lanes,
-                                u32 timer_clk_rate)
+static u8 csiphy_settle_cnt_calc(s64 link_freq, u32 timer_clk_rate)
 {
-       u32 mipi_clock; /* Hz */
        u32 ui; /* ps */
        u32 timer_period; /* ps */
        u32 t_hs_prepare_max; /* ps */
@@ -68,8 +65,10 @@ static u8 csiphy_settle_cnt_calc(u32 pixel_clock, u8 bpp, u8 num_lanes,
        u32 t_hs_settle; /* ps */
        u8 settle_cnt;
 
-       mipi_clock = pixel_clock * bpp / (2 * num_lanes);
-       ui = div_u64(1000000000000LL, mipi_clock);
+       if (link_freq <= 0)
+               return 0;
+
+       ui = div_u64(1000000000000LL, link_freq);
        ui /= 2;
        t_hs_prepare_max = 85000 + 6 * ui;
        t_hs_prepare_zero_min = 145000 + 10 * ui;
@@ -83,15 +82,14 @@ static u8 csiphy_settle_cnt_calc(u32 pixel_clock, u8 bpp, u8 num_lanes,
 
 static void csiphy_lanes_enable(struct csiphy_device *csiphy,
                                struct csiphy_config *cfg,
-                               u32 pixel_clock, u8 bpp, u8 lane_mask)
+                               s64 link_freq, u8 lane_mask)
 {
        struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg;
        u8 settle_cnt;
        u8 val, l = 0;
        int i = 0;
 
-       settle_cnt = csiphy_settle_cnt_calc(pixel_clock, bpp, c->num_data,
-                                           csiphy->timer_clk_rate);
+       settle_cnt = csiphy_settle_cnt_calc(link_freq, csiphy->timer_clk_rate);
 
        writel_relaxed(0x1, csiphy->base +
                       CAMSS_CSI_PHY_GLBL_T_INIT_CFG0);

diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
index 97cb9de850315fa385700a834a45e094fa25f444..da7c3d3f9a104d520d4e4ac04602756cefdebd9e 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
+++ b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
@@ -107,24 +107,23 @@ static irqreturn_t csiphy_isr(int irq, void *dev)
  *
  * Helper function to calculate settle count value. This is
  * based on the CSI2 T_hs_settle parameter which in turn
- * is calculated based on the CSI2 transmitter pixel clock
- * frequency.
+ * is calculated based on the CSI2 transmitter link frequency.
  *
- * Return settle count value or 0 if the CSI2 pixel clock
- * frequency is not available
+ * Return settle count value or 0 if the CSI2 link frequency
+ * is not available
  */
-static u8 csiphy_settle_cnt_calc(u32 pixel_clock, u8 bpp, u8 num_lanes,
-                                u32 timer_clk_rate)
+static u8 csiphy_settle_cnt_calc(s64 link_freq, u32 timer_clk_rate)
 {
-       u32 mipi_clock; /* Hz */
        u32 ui; /* ps */
        u32 timer_period; /* ps */
        u32 t_hs_prepare_max; /* ps */
        u32 t_hs_settle; /* ps */
        u8 settle_cnt;
 
-       mipi_clock = pixel_clock * bpp / (2 * num_lanes);
-       ui = div_u64(1000000000000LL, mipi_clock);
+       if (link_freq <= 0)
+               return 0;
+
+       ui = div_u64(1000000000000LL, link_freq);
        ui /= 2;
        t_hs_prepare_max = 85000 + 6 * ui;
        t_hs_settle = t_hs_prepare_max;
@@ -137,15 +136,14 @@ static u8 csiphy_settle_cnt_calc(u32 pixel_clock, u8 bpp, u8 num_lanes,
 
 static void csiphy_lanes_enable(struct csiphy_device *csiphy,
                                struct csiphy_config *cfg,
-                               u32 pixel_clock, u8 bpp, u8 lane_mask)
+                               s64 link_freq, u8 lane_mask)
 {
        struct csiphy_lanes_cfg *c = &cfg->csi2->lane_cfg;
        u8 settle_cnt;
        u8 val, l = 0;
        int i;
 
-       settle_cnt = csiphy_settle_cnt_calc(pixel_clock, bpp, c->num_data,
-                                           csiphy->timer_clk_rate);
+       settle_cnt = csiphy_settle_cnt_calc(link_freq, csiphy->timer_clk_rate);
 
        val = BIT(c->clk.pos);
        for (i = 0; i < c->num_data; i++)

diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.c b/drivers/media/platform/qcom/camss/camss-csiphy.c
index 509c9a59c09cd6ff9a80993832fa6e3cdf5e2929..40384d7ca78cb277336c248ed0e3e9ec59cd7e61 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss-csiphy.c
+++ b/drivers/media/platform/qcom/camss/camss-csiphy.c
@@ -102,23 +102,23 @@ static u8 csiphy_get_bpp(const struct csiphy_format *formats,
 static int csiphy_set_clock_rates(struct csiphy_device *csiphy)
 {
        struct device *dev = csiphy->camss->dev;
-       u32 pixel_clock;
+       s64 link_freq;
        int i, j;
        int ret;
 
-       ret = camss_get_pixel_clock(&csiphy->subdev.entity, &pixel_clock);
-       if (ret)
-               pixel_clock = 0;
+       u8 bpp = csiphy_get_bpp(csiphy->formats, csiphy->nformats,
+                               csiphy->fmt[MSM_CSIPHY_PAD_SINK].code);
+       u8 num_lanes = csiphy->cfg.csi2->lane_cfg.num_data;
+
+       link_freq = camss_get_link_freq(&csiphy->subdev.entity, bpp, num_lanes);
+       if (link_freq < 0)
+               link_freq  = 0;
 
        for (i = 0; i < csiphy->nclocks; i++) {
                struct camss_clock *clock = &csiphy->clock[i];
 
                if (csiphy->rate_set[i]) {
-                       u8 bpp = csiphy_get_bpp(csiphy->formats,
-                                       csiphy->nformats,
-                                       csiphy->fmt[MSM_CSIPHY_PAD_SINK].code);
-                       u8 num_lanes = csiphy->cfg.csi2->lane_cfg.num_data;
-                       u64 min_rate = pixel_clock * bpp / (2 * num_lanes * 4);
+                       u64 min_rate = link_freq / 4;
                        long round_rate;
 
                        camss_add_clock_margin(&min_rate);
@@ -238,22 +238,18 @@ static u8 csiphy_get_lane_mask(struct csiphy_lanes_cfg *lane_cfg)
 static int csiphy_stream_on(struct csiphy_device *csiphy)
 {
        struct csiphy_config *cfg = &csiphy->cfg;
-       u32 pixel_clock;
+       s64 link_freq;
        u8 lane_mask = csiphy_get_lane_mask(&cfg->csi2->lane_cfg);
        u8 bpp = csiphy_get_bpp(csiphy->formats, csiphy->nformats,
                                csiphy->fmt[MSM_CSIPHY_PAD_SINK].code);
+       u8 num_lanes = csiphy->cfg.csi2->lane_cfg.num_data;
        u8 val;
-       int ret;
 
-       ret = camss_get_pixel_clock(&csiphy->subdev.entity, &pixel_clock);
-       if (ret) {
-               dev_err(csiphy->camss->dev,
-                       "Cannot get CSI2 transmitter's pixel clock\n");
-               return -EINVAL;
-       }
-       if (!pixel_clock) {
+       link_freq = camss_get_link_freq(&csiphy->subdev.entity, bpp, num_lanes);
+
+       if (link_freq < 0) {
                dev_err(csiphy->camss->dev,
-                       "Got pixel clock == 0, cannot continue\n");
+                       "Cannot get CSI2 transmitter's link frequency\n");
                return -EINVAL;
        }
 
@@ -268,7 +264,7 @@ static int csiphy_stream_on(struct csiphy_device *csiphy)
        writel_relaxed(val, csiphy->base_clk_mux);
        wmb();
 
-       csiphy->ops->lanes_enable(csiphy, cfg, pixel_clock, bpp, lane_mask);
+       csiphy->ops->lanes_enable(csiphy, cfg, link_freq, lane_mask);
 
        return 0;
 }

diff --git a/drivers/media/platform/qcom/camss/camss-csiphy.h b/drivers/media/platform/qcom/camss/camss-csiphy.h
index f7967ef836dccfc4cdb046fcb50a31aa2a121aa8..d71b8bc6ec0079738c260ee75cb5b8c9d7148579 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss-csiphy.h
+++ b/drivers/media/platform/qcom/camss/camss-csiphy.h
@@ -50,7 +50,7 @@ struct csiphy_hw_ops {
        void (*reset)(struct csiphy_device *csiphy);
        void (*lanes_enable)(struct csiphy_device *csiphy,
                             struct csiphy_config *cfg,
-                            u32 pixel_clock, u8 bpp, u8 lane_mask);
+                            s64 link_freq, u8 lane_mask);
        void (*lanes_disable)(struct csiphy_device *csiphy,
                              struct csiphy_config *cfg);
        irqreturn_t (*isr)(int irq, void *dev);

diff --git a/drivers/media/platform/qcom/camss/camss.c b/drivers/media/platform/qcom/camss/camss.c
index 7c0f669f8aa6a143fe3b8827960a796202743c77..eb8fb8c34acd9f5fcec6f0821b00e8300b3942f9 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss.c
+++ b/drivers/media/platform/qcom/camss/camss.c
@@ -548,6 +548,29 @@ struct media_entity *camss_find_sensor(struct media_entity *entity)
        }
 }
 
+/**
+ * camss_get_link_freq - Get link frequency from sensor
+ * @entity: Media entity in the current pipeline
+ * @bpp: Number of bits per pixel for the current format
+ * @lanes: Number of lanes in the link to the sensor
+ *
+ * Return link frequency on success or a negative error code otherwise
+ */
+s64 camss_get_link_freq(struct media_entity *entity, unsigned int bpp,
+                       unsigned int lanes)
+{
+       struct media_entity *sensor;
+       struct v4l2_subdev *subdev;
+
+       sensor = camss_find_sensor(entity);
+       if (!sensor)
+               return -ENODEV;
+
+       subdev = media_entity_to_v4l2_subdev(sensor);
+
+       return v4l2_get_link_freq(subdev->ctrl_handler, bpp, 2 * lanes);
+}
+
 /*
  * camss_get_pixel_clock - Get pixel clock rate from sensor
  * @entity: Media entity in the current pipeline

diff --git a/drivers/media/platform/qcom/camss/camss.h b/drivers/media/platform/qcom/camss/camss.h
index 3a0484683cd6e1c808df74bcb56ff92eaa379c21..86cdc25189eb772640ef8277f69ce6694e7b2370 100644 (file)
--- a/drivers/media/platform/qcom/camss/camss.h
+++ b/drivers/media/platform/qcom/camss/camss.h
@@ -108,6 +108,8 @@ int camss_enable_clocks(int nclocks, struct camss_clock *clock,
                        struct device *dev);
 void camss_disable_clocks(int nclocks, struct camss_clock *clock);
 struct media_entity *camss_find_sensor(struct media_entity *entity);
+s64 camss_get_link_freq(struct media_entity *entity, unsigned int bpp,
+                       unsigned int lanes);
 int camss_get_pixel_clock(struct media_entity *entity, u32 *pixel_clock);
 int camss_pm_domain_on(struct camss *camss, int id);
 void camss_pm_domain_off(struct camss *camss, int id);