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Message-ID: <YErW3cicdN4vPCkM@builder.lan>
Date: Thu, 11 Mar 2021 20:50:05 -0600
From: Bjorn Andersson <bjorn.andersson@...aro.org>
To: Douglas Anderson <dianders@...omium.org>
Cc: Andrzej Hajda <a.hajda@...sung.com>,
Neil Armstrong <narmstrong@...libre.com>,
Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
Jonas Karlman <jonas@...boo.se>,
Jernej Skrabec <jernej.skrabec@...l.net>,
Sam Ravnborg <sam@...nborg.org>,
Stephen Boyd <swboyd@...omium.org>,
linux-arm-msm@...r.kernel.org, robdclark@...omium.org,
Daniel Vetter <daniel@...ll.ch>,
David Airlie <airlied@...ux.ie>,
dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] drm/bridge: ti-sn65dsi86: Move code in prep for EDID
read fix
On Thu 04 Mar 17:52 CST 2021, Douglas Anderson wrote:
> This patch is _only_ code motion to prepare for the patch
> ("drm/bridge: ti-sn65dsi86: Properly get the EDID, but only if
> refclk") and make it easier to understand.
>
Reviewed-by: Bjorn Andersson <bjorn.andersson@...aro.org>
Regards,
Bjorn
> Signed-off-by: Douglas Anderson <dianders@...omium.org>
> ---
>
> drivers/gpu/drm/bridge/ti-sn65dsi86.c | 196 +++++++++++++-------------
> 1 file changed, 98 insertions(+), 98 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index 942019842ff4..491c9c4f32d1 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -345,6 +345,104 @@ static int ti_sn_bridge_parse_regulators(struct ti_sn_bridge *pdata)
> pdata->supplies);
> }
>
> +static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn_bridge *pdata)
> +{
> + u32 bit_rate_khz, clk_freq_khz;
> + struct drm_display_mode *mode =
> + &pdata->bridge.encoder->crtc->state->adjusted_mode;
> +
> + bit_rate_khz = mode->clock *
> + mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
> + clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
> +
> + return clk_freq_khz;
> +}
> +
> +/* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
> +static const u32 ti_sn_bridge_refclk_lut[] = {
> + 12000000,
> + 19200000,
> + 26000000,
> + 27000000,
> + 38400000,
> +};
> +
> +/* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
> +static const u32 ti_sn_bridge_dsiclk_lut[] = {
> + 468000000,
> + 384000000,
> + 416000000,
> + 486000000,
> + 460800000,
> +};
> +
> +static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata)
> +{
> + int i;
> + u32 refclk_rate;
> + const u32 *refclk_lut;
> + size_t refclk_lut_size;
> +
> + if (pdata->refclk) {
> + refclk_rate = clk_get_rate(pdata->refclk);
> + refclk_lut = ti_sn_bridge_refclk_lut;
> + refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
> + clk_prepare_enable(pdata->refclk);
> + } else {
> + refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
> + refclk_lut = ti_sn_bridge_dsiclk_lut;
> + refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
> + }
> +
> + /* for i equals to refclk_lut_size means default frequency */
> + for (i = 0; i < refclk_lut_size; i++)
> + if (refclk_lut[i] == refclk_rate)
> + break;
> +
> + regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
> + REFCLK_FREQ(i));
> +}
> +
> +static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
> +{
> + struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> +
> + clk_disable_unprepare(pdata->refclk);
> +
> + pm_runtime_put_sync(pdata->dev);
> +}
> +
> +static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
> +{
> + struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> +
> + pm_runtime_get_sync(pdata->dev);
> +
> + /* configure bridge ref_clk */
> + ti_sn_bridge_set_refclk_freq(pdata);
> +
> + /*
> + * HPD on this bridge chip is a bit useless. This is an eDP bridge
> + * so the HPD is an internal signal that's only there to signal that
> + * the panel is done powering up. ...but the bridge chip debounces
> + * this signal by between 100 ms and 400 ms (depending on process,
> + * voltage, and temperate--I measured it at about 200 ms). One
> + * particular panel asserted HPD 84 ms after it was powered on meaning
> + * that we saw HPD 284 ms after power on. ...but the same panel said
> + * that instead of looking at HPD you could just hardcode a delay of
> + * 200 ms. We'll assume that the panel driver will have the hardcoded
> + * delay in its prepare and always disable HPD.
> + *
> + * If HPD somehow makes sense on some future panel we'll have to
> + * change this to be conditional on someone specifying that HPD should
> + * be used.
> + */
> + regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
> + HPD_DISABLE);
> +
> + drm_panel_prepare(pdata->panel);
> +}
> +
> static int ti_sn_bridge_attach(struct drm_bridge *bridge,
> enum drm_bridge_attach_flags flags)
> {
> @@ -443,64 +541,6 @@ static void ti_sn_bridge_disable(struct drm_bridge *bridge)
> drm_panel_unprepare(pdata->panel);
> }
>
> -static u32 ti_sn_bridge_get_dsi_freq(struct ti_sn_bridge *pdata)
> -{
> - u32 bit_rate_khz, clk_freq_khz;
> - struct drm_display_mode *mode =
> - &pdata->bridge.encoder->crtc->state->adjusted_mode;
> -
> - bit_rate_khz = mode->clock *
> - mipi_dsi_pixel_format_to_bpp(pdata->dsi->format);
> - clk_freq_khz = bit_rate_khz / (pdata->dsi->lanes * 2);
> -
> - return clk_freq_khz;
> -}
> -
> -/* clk frequencies supported by bridge in Hz in case derived from REFCLK pin */
> -static const u32 ti_sn_bridge_refclk_lut[] = {
> - 12000000,
> - 19200000,
> - 26000000,
> - 27000000,
> - 38400000,
> -};
> -
> -/* clk frequencies supported by bridge in Hz in case derived from DACP/N pin */
> -static const u32 ti_sn_bridge_dsiclk_lut[] = {
> - 468000000,
> - 384000000,
> - 416000000,
> - 486000000,
> - 460800000,
> -};
> -
> -static void ti_sn_bridge_set_refclk_freq(struct ti_sn_bridge *pdata)
> -{
> - int i;
> - u32 refclk_rate;
> - const u32 *refclk_lut;
> - size_t refclk_lut_size;
> -
> - if (pdata->refclk) {
> - refclk_rate = clk_get_rate(pdata->refclk);
> - refclk_lut = ti_sn_bridge_refclk_lut;
> - refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_refclk_lut);
> - clk_prepare_enable(pdata->refclk);
> - } else {
> - refclk_rate = ti_sn_bridge_get_dsi_freq(pdata) * 1000;
> - refclk_lut = ti_sn_bridge_dsiclk_lut;
> - refclk_lut_size = ARRAY_SIZE(ti_sn_bridge_dsiclk_lut);
> - }
> -
> - /* for i equals to refclk_lut_size means default frequency */
> - for (i = 0; i < refclk_lut_size; i++)
> - if (refclk_lut[i] == refclk_rate)
> - break;
> -
> - regmap_update_bits(pdata->regmap, SN_DPPLL_SRC_REG, REFCLK_FREQ_MASK,
> - REFCLK_FREQ(i));
> -}
> -
> static void ti_sn_bridge_set_dsi_rate(struct ti_sn_bridge *pdata)
> {
> unsigned int bit_rate_mhz, clk_freq_mhz;
> @@ -821,46 +861,6 @@ static void ti_sn_bridge_enable(struct drm_bridge *bridge)
> drm_panel_enable(pdata->panel);
> }
>
> -static void ti_sn_bridge_pre_enable(struct drm_bridge *bridge)
> -{
> - struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> -
> - pm_runtime_get_sync(pdata->dev);
> -
> - /* configure bridge ref_clk */
> - ti_sn_bridge_set_refclk_freq(pdata);
> -
> - /*
> - * HPD on this bridge chip is a bit useless. This is an eDP bridge
> - * so the HPD is an internal signal that's only there to signal that
> - * the panel is done powering up. ...but the bridge chip debounces
> - * this signal by between 100 ms and 400 ms (depending on process,
> - * voltage, and temperate--I measured it at about 200 ms). One
> - * particular panel asserted HPD 84 ms after it was powered on meaning
> - * that we saw HPD 284 ms after power on. ...but the same panel said
> - * that instead of looking at HPD you could just hardcode a delay of
> - * 200 ms. We'll assume that the panel driver will have the hardcoded
> - * delay in its prepare and always disable HPD.
> - *
> - * If HPD somehow makes sense on some future panel we'll have to
> - * change this to be conditional on someone specifying that HPD should
> - * be used.
> - */
> - regmap_update_bits(pdata->regmap, SN_HPD_DISABLE_REG, HPD_DISABLE,
> - HPD_DISABLE);
> -
> - drm_panel_prepare(pdata->panel);
> -}
> -
> -static void ti_sn_bridge_post_disable(struct drm_bridge *bridge)
> -{
> - struct ti_sn_bridge *pdata = bridge_to_ti_sn_bridge(bridge);
> -
> - clk_disable_unprepare(pdata->refclk);
> -
> - pm_runtime_put_sync(pdata->dev);
> -}
> -
> static const struct drm_bridge_funcs ti_sn_bridge_funcs = {
> .attach = ti_sn_bridge_attach,
> .pre_enable = ti_sn_bridge_pre_enable,
> --
> 2.30.1.766.gb4fecdf3b7-goog
>
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