Re: [PATCH RESEND v2] drm/bridge/tc358775: Fixes bus formats read

Hi Vinay,

Thank you for the patch.

I'm afraid I've had close to no time for DRM bridge maintenance over the past few months, and I don't expect the situation to improve soon. I know how painful it can be to keep pinging without receiving any reply. I'm sorry about that, we have a shortage of maintainers for this part of the subsystem and it seems difficult to recruit.

On Thu, Oct 22, 2020 at 12:15:47PM +0530, Vinay Simha BN wrote:

• atomic_check removed
• video data input and output formats added
• bus formats read from drm_bridge_state.output_bus_cfg.format and .atomic_get_input_bus_fmts() instead of connector

Signed-off-by: Vinay Simha BN simhavcs@gmail.com

---

v1:

• Laurent Pinchart review comments incorporated drm_bridge_state.output_bus_cfg.format instead of connector

v2:

• Laurent Pinchart review comments incorporated atomic_check removed video data input and output formats added

---

drivers/gpu/drm/bridge/tc358775.c | 75 ++++++++++++++++++++++++++++++--------- 1 file changed, 58 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/bridge/tc358775.c b/drivers/gpu/drm/bridge/tc358775.c index 2272adc..cc27570 100644 --- a/drivers/gpu/drm/bridge/tc358775.c +++ b/drivers/gpu/drm/bridge/tc358775.c @@ -271,6 +271,20 @@ struct tc_data { struct gpio_desc *stby_gpio; u8 lvds_link; /* single-link or dual-link */ u8 bpc;

• u32 output_bus_fmt;

+};

+static const u32 tc_lvds_in_bus_fmts[] = {

• MEDIA_BUS_FMT_RGB565_1X16,
• MEDIA_BUS_FMT_RGB666_1X18,
• MEDIA_BUS_FMT_RGB666_1X24_CPADHI,
• MEDIA_BUS_FMT_RBG888_1X24,

+};

+static const u32 tc_lvds_out_bus_fmts[] = {

• MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,
• MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
• MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,

};

static inline struct tc_data *bridge_to_tc(struct drm_bridge *b) @@ -359,19 +373,6 @@ static void d2l_write(struct i2c_client *i2c, u16 addr, u32 val) ret, addr); }

-/* helper function to access bus_formats */ -static struct drm_connector *get_connector(struct drm_encoder *encoder) -{

• struct drm_device *dev = encoder->dev;
• struct drm_connector *connector;
• list_for_each_entry(connector, &dev->mode_config.connector_list, head)

• if (connector->encoder == encoder)
  

• 	return connector;
  

• return NULL;

-}

static void tc_bridge_enable(struct drm_bridge *bridge) { struct tc_data *tc = bridge_to_tc(bridge); @@ -380,7 +381,10 @@ static void tc_bridge_enable(struct drm_bridge *bridge) u32 val = 0; u16 dsiclk, clkdiv, byteclk, t1, t2, t3, vsdelay; struct drm_display_mode *mode;

• struct drm_connector *connector = get_connector(bridge->encoder);

• struct drm_bridge_state *state =

• 	drm_priv_to_bridge_state(bridge->base.state);
  

• tc->output_bus_fmt = state->output_bus_cfg.format;

  mode = &bridge->encoder->crtc->state->adjusted_mode;

@@ -451,14 +455,13 @@ static void tc_bridge_enable(struct drm_bridge *bridge) d2l_write(tc->i2c, LVPHY0, LV_PHY0_PRBS_ON(4) | LV_PHY0_ND(6));

dev_dbg(tc->dev, "bus_formats %04x bpc %d\n",

• connector->display_info.bus_formats[0],
  

• tc->output_bus_fmt,
  

  tc->bpc); /*
  • Default hardware register settings of tc358775 configured
  • with MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA jeida-24 format
  */

• if (connector->display_info.bus_formats[0] ==

• MEDIA_BUS_FMT_RGB888_1X7X4_SPWG) {
  

• if (tc->output_bus_fmt == MEDIA_BUS_FMT_RGB888_1X7X4_SPWG) {

As output_bus_fmt is only used in this function, I would make this a local variable and drop the output_bus_fmt field from tc_data. You could even use state->output_bus_cfg.format directly in the two locations where the value is needed without a local variable, up to you.

/* VESA-24 */
d2l_write(tc->i2c, LV_MX0003, LV_MX(LVI_R0, LVI_R1, LVI_R2, LVI_R3));
d2l_write(tc->i2c, LV_MX0407, LV_MX(LVI_R4, LVI_R7, LVI_R5, LVI_G0));

@@ -590,6 +593,40 @@ static int tc358775_parse_dt(struct device_node *np, struct tc_data *tc) return 0; }

+static u32 * +tc_bridge_get_input_bus_fmts(struct drm_bridge *bridge,

• 	     struct drm_bridge_state *bridge_state,
  

• 	     struct drm_crtc_state *crtc_state,
  

• 	     struct drm_connector_state *conn_state,
  

• 	     u32 output_fmt,
  

• 	     unsigned int *num_input_fmts)
  

+{

• u32 *input_fmts = NULL;
• u8 i;

You can make this an unsigned int, a u8 won't save space of CPU time.

• *num_input_fmts = 0;
• for (i = 0 ; i < ARRAY_SIZE(tc_lvds_out_bus_fmts) ; ++i) {

• if (output_fmt == tc_lvds_out_bus_fmts[i])
  

• 	break;
  

• }
• if (i == ARRAY_SIZE(tc_lvds_out_bus_fmts))

• return NULL;
  

• *num_input_fmts = ARRAY_SIZE(tc_lvds_in_bus_fmts);
• input_fmts = kcalloc(*num_input_fmts, ARRAY_SIZE(tc_lvds_in_bus_fmts),

• 	     GFP_KERNEL);
  

• if (!input_fmts)

• return NULL;
  

• for (i = 0; i < ARRAY_SIZE(tc_lvds_in_bus_fmts); ++i)

• input_fmts[i] = tc_lvds_in_bus_fmts[i];
  

This could be written

memcpy(input_fmts, tc_lvds_in_bus_fmts, sizeof(input_fmts));

With those small changes,

Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

• return input_fmts;

+}

static int tc_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) { @@ -639,6 +676,10 @@ static int tc_bridge_attach(struct drm_bridge *bridge, }

static const struct drm_bridge_funcs tc_bridge_funcs = {

• .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
• .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
• .atomic_reset = drm_atomic_helper_bridge_reset,
• .atomic_get_input_bus_fmts = tc_bridge_get_input_bus_fmts, .attach = tc_bridge_attach, .pre_enable = tc_bridge_pre_enable, .enable = tc_bridge_enable,