From: Laurent Pinchart Date: Fri, 27 Jul 2018 12:29:08 +0000 (+0300) Subject: drm: rcar-du: Rework clock configuration based on hardware limits X-Git-Tag: v5.4-rc1~2273^2~28^2~8 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7281e6c6a5bdbde9cae6eb3c6d2bf2706b94807d;p=platform%2Fkernel%2Flinux-rpi.git drm: rcar-du: Rework clock configuration based on hardware limits The DU channels that have a display PLL (DPLL) can only use external clock sources, and don't have an internal clock divider (with the exception of H3 ES1.x where the post-divider is present and needs to be used as a workaround for a DPLL silicon issue). Rework the clock configuration to take this into account, avoiding selection of non-existing clock sources or usage of a missing post-divider. Signed-off-by: Laurent Pinchart Reviewed-by: Jacopo Mondi --- diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index 175c36c..687e812 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -204,78 +204,90 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) const struct drm_display_mode *mode = &rcrtc->crtc.state->adjusted_mode; struct rcar_du_device *rcdu = rcrtc->group->dev; unsigned long mode_clock = mode->clock * 1000; - unsigned long clk; - u32 value; + u32 dsmr; u32 escr; - u32 div; - /* - * Compute the clock divisor and select the internal or external dot - * clock based on the requested frequency. - */ - clk = clk_get_rate(rcrtc->clock); - div = DIV_ROUND_CLOSEST(clk, mode_clock); - div = clamp(div, 1U, 64U) - 1; - escr = div | ESCR_DCLKSEL_CLKS; - - if (rcrtc->extclock) { + if (rcdu->info->dpll_ch & (1 << rcrtc->index)) { + unsigned long target = mode_clock; struct dpll_info dpll = { 0 }; unsigned long extclk; - unsigned long extrate; - unsigned long rate; - u32 extdiv; + u32 dpllcr; + u32 div = 0; - extclk = clk_get_rate(rcrtc->extclock); - if (rcdu->info->dpll_ch & (1 << rcrtc->index)) { - unsigned long target = mode_clock; + /* + * DU channels that have a display PLL can't use the internal + * system clock, and have no internal clock divider. + */ - /* - * The H3 ES1.x exhibits dot clock duty cycle stability - * issues. We can work around them by configuring the - * DPLL to twice the desired frequency, coupled with a - * /2 post-divider. This isn't needed on other SoCs and - * breaks HDMI output on M3-W for a currently unknown - * reason, so restrict the workaround to H3 ES1.x. - */ - if (soc_device_match(rcar_du_r8a7795_es1)) - target *= 2; + if (WARN_ON(!rcrtc->extclock)) + return; - rcar_du_dpll_divider(rcrtc, &dpll, extclk, target); - extclk = dpll.output; + /* + * The H3 ES1.x exhibits dot clock duty cycle stability issues. + * We can work around them by configuring the DPLL to twice the + * desired frequency, coupled with a /2 post-divider. Restrict + * the workaround to H3 ES1.x as ES2.0 and all other SoCs have + * no post-divider when a display PLL is present (as shown by + * the workaround breaking HDMI output on M3-W during testing). + */ + if (soc_device_match(rcar_du_r8a7795_es1)) { + target *= 2; + div = 1; } - extdiv = DIV_ROUND_CLOSEST(extclk, mode_clock); - extdiv = clamp(extdiv, 1U, 64U) - 1; + extclk = clk_get_rate(rcrtc->extclock); + rcar_du_dpll_divider(rcrtc, &dpll, extclk, target); - rate = clk / (div + 1); - extrate = extclk / (extdiv + 1); + dpllcr = DPLLCR_CODE | DPLLCR_CLKE + | DPLLCR_FDPLL(dpll.fdpll) + | DPLLCR_N(dpll.n) | DPLLCR_M(dpll.m) + | DPLLCR_STBY; - if (abs((long)extrate - (long)mode_clock) < - abs((long)rate - (long)mode_clock)) { + if (rcrtc->index == 1) + dpllcr |= DPLLCR_PLCS1 + | DPLLCR_INCS_DOTCLKIN1; + else + dpllcr |= DPLLCR_PLCS0 + | DPLLCR_INCS_DOTCLKIN0; - if (rcdu->info->dpll_ch & (1 << rcrtc->index)) { - u32 dpllcr = DPLLCR_CODE | DPLLCR_CLKE - | DPLLCR_FDPLL(dpll.fdpll) - | DPLLCR_N(dpll.n) | DPLLCR_M(dpll.m) - | DPLLCR_STBY; + rcar_du_group_write(rcrtc->group, DPLLCR, dpllcr); - if (rcrtc->index == 1) - dpllcr |= DPLLCR_PLCS1 - | DPLLCR_INCS_DOTCLKIN1; - else - dpllcr |= DPLLCR_PLCS0 - | DPLLCR_INCS_DOTCLKIN0; + escr = ESCR_DCLKSEL_DCLKIN | div; + } else { + unsigned long clk; + u32 div; - rcar_du_group_write(rcrtc->group, DPLLCR, - dpllcr); - } + /* + * Compute the clock divisor and select the internal or external + * dot clock based on the requested frequency. + */ + clk = clk_get_rate(rcrtc->clock); + div = DIV_ROUND_CLOSEST(clk, mode_clock); + div = clamp(div, 1U, 64U) - 1; - escr = ESCR_DCLKSEL_DCLKIN | extdiv; - } + escr = ESCR_DCLKSEL_CLKS | div; - dev_dbg(rcrtc->group->dev->dev, - "mode clock %lu extrate %lu rate %lu ESCR 0x%08x\n", - mode_clock, extrate, rate, escr); + if (rcrtc->extclock) { + unsigned long extclk; + unsigned long extrate; + unsigned long rate; + u32 extdiv; + + extclk = clk_get_rate(rcrtc->extclock); + extdiv = DIV_ROUND_CLOSEST(extclk, mode_clock); + extdiv = clamp(extdiv, 1U, 64U) - 1; + + extrate = extclk / (extdiv + 1); + rate = clk / (div + 1); + + if (abs((long)extrate - (long)mode_clock) < + abs((long)rate - (long)mode_clock)) + escr = ESCR_DCLKSEL_DCLKIN | extdiv; + + dev_dbg(rcrtc->group->dev->dev, + "mode clock %lu extrate %lu rate %lu ESCR 0x%08x\n", + mode_clock, extrate, rate, escr); + } } rcar_du_group_write(rcrtc->group, rcrtc->index % 2 ? ESCR2 : ESCR, @@ -283,11 +295,11 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) rcar_du_group_write(rcrtc->group, rcrtc->index % 2 ? OTAR2 : OTAR, 0); /* Signal polarities */ - value = ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? DSMR_VSL : 0) - | ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? DSMR_HSL : 0) - | ((mode->flags & DRM_MODE_FLAG_INTERLACE) ? DSMR_ODEV : 0) - | DSMR_DIPM_DISP | DSMR_CSPM; - rcar_du_crtc_write(rcrtc, DSMR, value); + dsmr = ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? DSMR_VSL : 0) + | ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? DSMR_HSL : 0) + | ((mode->flags & DRM_MODE_FLAG_INTERLACE) ? DSMR_ODEV : 0) + | DSMR_DIPM_DISP | DSMR_CSPM; + rcar_du_crtc_write(rcrtc, DSMR, dsmr); /* Display timings */ rcar_du_crtc_write(rcrtc, HDSR, mode->htotal - mode->hsync_start - 19);