From: Dharma Balasubiramani <[email protected]> The LVDS PLL clock runs at 7 times the panel pixel clock. For LVDS displays, the PLL clock rate is set based on the panel pixel clock, eliminating the need for the assigned-clock-rates Device Tree property for lvds_pll_clk in the LCD node.
Signed-off-by: Dharma Balasubiramani <[email protected]> Signed-off-by: Manikandan Muralidharan <[email protected]> --- Changes in v2: - Rephrase commit message and comment block --- .../gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 48 ++++++++++++++++--- 1 file changed, 42 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c index beb825fc4d5d..67860947c466 100644 --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c @@ -100,9 +100,15 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c) drm_connector_list_iter_end(&iter); } - ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk); - if (ret) - return; + if (crtc->dc->hlcdc->lvds_pll_clk) { + ret = clk_prepare_enable(crtc->dc->hlcdc->lvds_pll_clk); + if (ret) + return; + } else { + ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk); + if (ret) + return; + } vm.vfront_porch = adj->crtc_vsync_start - adj->crtc_vdisplay; vm.vback_porch = adj->crtc_vtotal - adj->crtc_vsync_end; @@ -187,7 +193,10 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c) ATMEL_XLCDC_DPI : ATMEL_HLCDC_MODE_MASK), cfg); - clk_disable_unprepare(crtc->dc->hlcdc->sys_clk); + if (crtc->dc->hlcdc->lvds_pll_clk) + clk_disable_unprepare(crtc->dc->hlcdc->lvds_pll_clk); + else + clk_disable_unprepare(crtc->dc->hlcdc->sys_clk); } static enum drm_mode_status @@ -243,7 +252,11 @@ static void atmel_hlcdc_crtc_atomic_disable(struct drm_crtc *c, 10, 1000)) drm_warn(dev, "Atmel LCDC status register CLKSTS timeout\n"); - clk_disable_unprepare(crtc->dc->hlcdc->sys_clk); + if (crtc->dc->hlcdc->lvds_pll_clk) + clk_disable_unprepare(crtc->dc->hlcdc->lvds_pll_clk); + else + clk_disable_unprepare(crtc->dc->hlcdc->sys_clk); + pinctrl_pm_select_sleep_state(dev->dev); pm_runtime_allow(dev->dev); @@ -256,15 +269,38 @@ static void atmel_hlcdc_crtc_atomic_enable(struct drm_crtc *c, { struct drm_device *dev = c->dev; struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c); + struct drm_display_mode *adj = &c->state->adjusted_mode; struct regmap *regmap = crtc->dc->hlcdc->regmap; unsigned int status; + int ret; pm_runtime_get_sync(dev->dev); pm_runtime_forbid(dev->dev); pinctrl_pm_select_default_state(dev->dev); - clk_prepare_enable(crtc->dc->hlcdc->sys_clk); + + if (crtc->dc->hlcdc->lvds_pll_clk) { + /* + * For LVDS displays, retrieve the pixel clock from the panel + * and set the LVDS PLL clock rate accordingly. + * According to the datasheet,the LVDS PLL clock is 7 times the pixel clock. + */ + ret = clk_set_rate(crtc->dc->hlcdc->lvds_pll_clk, + (adj->clock * 7 * 1000)); + if (ret) { + dev_err(dev->dev, "Failed to set LVDS PLL clk rate: %d\n", ret); + return; + } + + ret = clk_prepare_enable(crtc->dc->hlcdc->lvds_pll_clk); + if (ret) + return; + } else { + ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk); + if (ret) + return; + } regmap_write(regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PIXEL_CLK); if (regmap_read_poll_timeout(regmap, ATMEL_HLCDC_SR, status, -- 2.25.1
