drm/tilcdc: Clean up LCDC functional clock rate setting code

Clean up LCDC functional clock rate setting code.

The LCDC functional clock is set by two functions: mode_set_nofb() and
cpufreq_transition().

When tilcdc_crtc_mode_set_nofb() is called in atomic commit phase the
drm atomic helpers have taken all the necessary drm locks and turned
off the crtc, while tilcdc_commit() is keeping LCDC powered on. For
mode_set_nofb() just a simple clock setting function without any
locking or power management code is enough. The new tilcdc_crtc_set_clk()
is implemented for that purpose.

cpufreq_transition() on the other hand is called from outside DRM and
it needs to take the necessary locks and turn off the CRTC while
keeping the LCDC powered. The reimplemented tilcdc_crtc_update_clk()
is for that purpose and it uses the new tilcdc_crtc_set_clk() to
actually set the clock.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index 2087689..5579d97 100644 (file)
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -35,6 +35,8 @@ struct tilcdc_crtc {
        bool frame_done;
        spinlock_t irq_lock;
 
+       unsigned int lcd_fck_rate;
+
        ktime_t last_vblank;
 
        struct drm_framebuffer *curr_fb;
@@ -304,6 +306,37 @@ static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
        return true;
 }
 
+static void tilcdc_crtc_set_clk(struct drm_crtc *crtc)
+{
+       struct drm_device *dev = crtc->dev;
+       struct tilcdc_drm_private *priv = dev->dev_private;
+       struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+       const unsigned clkdiv = 2; /* using a fixed divider of 2 */
+       int ret;
+
+       /* mode.clock is in KHz, set_rate wants parameter in Hz */
+       ret = clk_set_rate(priv->clk, crtc->mode.clock * 1000 * clkdiv);
+       if (ret < 0) {
+               dev_err(dev->dev, "failed to set display clock rate to: %d\n",
+                       crtc->mode.clock);
+               return;
+       }
+
+       tilcdc_crtc->lcd_fck_rate = clk_get_rate(priv->clk);
+
+       DBG("lcd_clk=%u, mode clock=%d, div=%u",
+           tilcdc_crtc->lcd_fck_rate, crtc->mode.clock, clkdiv);
+
+       /* Configure the LCD clock divisor. */
+       tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
+                    LCDC_RASTER_MODE);
+
+       if (priv->rev == 2)
+               tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
+                               LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
+                               LCDC_V2_CORE_CLK_EN);
+}
+
 static void tilcdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
        struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
@@ -466,7 +499,7 @@ static void tilcdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 
        set_scanout(crtc, fb);
 
-       tilcdc_crtc_update_clk(crtc);
+       tilcdc_crtc_set_clk(crtc);
 
        crtc->hwmode = crtc->state->adjusted_mode;
 }
@@ -635,41 +668,21 @@ void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
 {
        struct drm_device *dev = crtc->dev;
        struct tilcdc_drm_private *priv = dev->dev_private;
-       unsigned long lcd_clk;
-       const unsigned clkdiv = 2; /* using a fixed divider of 2 */
-       int ret;
+       struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
 
-       pm_runtime_get_sync(dev->dev);
+       drm_modeset_lock_crtc(crtc, NULL);
+       if (tilcdc_crtc->lcd_fck_rate != clk_get_rate(priv->clk)) {
+               if (tilcdc_crtc_is_on(crtc)) {
+                       pm_runtime_get_sync(dev->dev);
+                       tilcdc_crtc_disable(crtc);
 
-       tilcdc_crtc_disable(crtc);
+                       tilcdc_crtc_set_clk(crtc);
 
-       /* mode.clock is in KHz, set_rate wants parameter in Hz */
-       ret = clk_set_rate(priv->clk, crtc->mode.clock * 1000 * clkdiv);
-       if (ret < 0) {
-               dev_err(dev->dev, "failed to set display clock rate to: %d\n",
-                               crtc->mode.clock);
-               goto out;
+                       tilcdc_crtc_enable(crtc);
+                       pm_runtime_put_sync(dev->dev);
+               }
        }
-
-       lcd_clk = clk_get_rate(priv->clk);
-
-       DBG("lcd_clk=%lu, mode clock=%d, div=%u",
-               lcd_clk, crtc->mode.clock, clkdiv);
-
-       /* Configure the LCD clock divisor. */
-       tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(clkdiv) |
-                       LCDC_RASTER_MODE);
-
-       if (priv->rev == 2)
-               tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
-                               LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
-                               LCDC_V2_CORE_CLK_EN);
-
-       if (tilcdc_crtc_is_on(crtc))
-               tilcdc_crtc_enable(crtc);
-
-out:
-       pm_runtime_put_sync(dev->dev);
+       drm_modeset_unlock_crtc(crtc);
 }
 
 #define SYNC_LOST_COUNT_LIMIT 50

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index b1ac61e..52ff3e1 100644 (file)
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -185,14 +185,8 @@ static int cpufreq_transition(struct notifier_block *nb,
        struct tilcdc_drm_private *priv = container_of(nb,
                        struct tilcdc_drm_private, freq_transition);
 
-       if (val == CPUFREQ_POSTCHANGE) {
-               if (priv->lcd_fck_rate != clk_get_rate(priv->clk)) {
-                       drm_modeset_lock_crtc(priv->crtc, NULL);
-                       priv->lcd_fck_rate = clk_get_rate(priv->clk);
-                       tilcdc_crtc_update_clk(priv->crtc);
-                       drm_modeset_unlock_crtc(priv->crtc);
-               }
-       }
+       if (val == CPUFREQ_POSTCHANGE)
+               tilcdc_crtc_update_clk(priv->crtc);
 
        return 0;
 }
@@ -286,7 +280,6 @@ static int tilcdc_load(struct drm_device *dev, unsigned long flags)
        }
 
 #ifdef CONFIG_CPU_FREQ
-       priv->lcd_fck_rate = clk_get_rate(priv->clk);
        priv->freq_transition.notifier_call = cpufreq_transition;
        ret = cpufreq_register_notifier(&priv->freq_transition,
                        CPUFREQ_TRANSITION_NOTIFIER);

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
index a6e5e6d..9780c37 100644 (file)
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h
@@ -74,7 +74,6 @@ struct tilcdc_drm_private {
 
 #ifdef CONFIG_CPU_FREQ
        struct notifier_block freq_transition;
-       unsigned int lcd_fck_rate;
 #endif
 
        struct workqueue_struct *wq;