MALI: midgard: RK: slowdown clk_gpu before poweroff cores

This is a workaround for the issue that
"400M, 500M and 600M of clk_gpu needs high vdd_gpu",
according to "6.2" of Mali Application Note
"Potential glitches on Power Domain interfaces".

Change-Id: I8b8eccd2079e21ac5e1db7b4552c8f998f676a9f
Signed-off-by: chenzhen <chenzhen@rock-chips.com>

diff --git a/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c b/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c
index ad05fe5bea8d225d10d7ed1476a79f4d32ce1943..8f9a67e57ceaa3b97d9b93797d86e869a49c480f 100644 (file)
--- a/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c
+++ b/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c
@@ -54,7 +54,7 @@ kbase_devfreq_target(struct device *dev, unsigned long *target_freq, u32 flags)
        struct dev_pm_opp *opp;
        unsigned long freq = 0;
        unsigned long voltage;
-       int err;
+       int err = 0;
 
        freq = *target_freq;
 
@@ -86,7 +86,11 @@ kbase_devfreq_target(struct device *dev, unsigned long *target_freq, u32 flags)
        }
 #endif
 
-       err = clk_set_rate(kbdev->clock, freq);
+       mutex_lock(&kbdev->mutex_for_clk);
+       if (!kbdev->is_power_off)
+               err = clk_set_rate(kbdev->clock, freq);
+       kbdev->freq = freq;
+       mutex_unlock(&kbdev->mutex_for_clk);
        if (err) {
                dev_err(dev, "Failed to set clock %lu (target %lu)\n",
                                freq, *target_freq);

diff --git a/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c b/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c
index 711e44c7f80ad66c3d6611b1dd7f3f4dec7b1699..0919969da5231a143dae23d7ec0e4f33b78a0971 100644 (file)
--- a/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c
+++ b/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_pm_backend.c
@@ -20,6 +20,9 @@
  * GPU backend implementation of base kernel power management APIs
  */
 
+/* #define ENABLE_DEBUG_LOG */
+#include "../../platform/rk/custom_log.h"
+
 #include <mali_kbase.h>
 #include <mali_midg_regmap.h>
 #include <mali_kbase_config_defaults.h>
@@ -32,6 +35,36 @@
 #include <backend/gpu/mali_kbase_js_internal.h>
 #include <backend/gpu/mali_kbase_pm_internal.h>
 
+static int rk_slowdown_clk_gpu_before_poweroff_cores(struct kbase_device *kbdev)
+{
+       int ret = 0;
+       const unsigned long freq = 200 * 1000 * 1000;
+
+       mutex_lock(&kbdev->mutex_for_clk);
+       ret = clk_set_rate(kbdev->clock, freq);
+       if (ret)
+               E("Failed to set clock to %lu.", freq);
+       kbdev->is_power_off = true;
+       mutex_unlock(&kbdev->mutex_for_clk);
+
+       return ret;
+}
+
+static int rk_restore_clk_gpu(struct kbase_device *kbdev)
+{
+       int ret = 0;
+
+       mutex_lock(&kbdev->mutex_for_clk);
+       if (kbdev->freq != 0)
+               ret = clk_set_rate(kbdev->clock, kbdev->freq);
+       if (ret)
+               E("Failed to set clock to %lu.", kbdev->freq);
+       kbdev->is_power_off = false;
+       mutex_unlock(&kbdev->mutex_for_clk);
+
+       return ret;
+}
+
 void kbase_pm_register_access_enable(struct kbase_device *kbdev)
 {
        struct kbase_pm_callback_conf *callbacks;
@@ -155,6 +188,9 @@ void kbase_pm_do_poweron(struct kbase_device *kbdev, bool is_resume)
 
        /* NOTE: We don't wait to reach the desired state, since running atoms
         * will wait for that state to be reached anyway */
+
+       D("to restore clk_gpu.");
+       rk_restore_clk_gpu(kbdev);
 }
 
 bool kbase_pm_do_poweroff(struct kbase_device *kbdev, bool is_suspend)
@@ -164,6 +200,9 @@ bool kbase_pm_do_poweroff(struct kbase_device *kbdev, bool is_suspend)
 
        lockdep_assert_held(&kbdev->pm.lock);
 
+       D("to slowdown clk_gpu before poweroff pm_cores.");
+       rk_slowdown_clk_gpu_before_poweroff_cores(kbdev);
+
        spin_lock_irqsave(&kbdev->pm.power_change_lock, flags);
 
        /* Force all cores off */

diff --git a/drivers/gpu/arm/midgard/mali_kbase_core_linux.c b/drivers/gpu/arm/midgard/mali_kbase_core_linux.c
index ee59504cd4e87aaa798b6404510a2239d0144214..499ef46a0fe2957dcf2483d274642f8b03b1c94c 100644 (file)
--- a/drivers/gpu/arm/midgard/mali_kbase_core_linux.c
+++ b/drivers/gpu/arm/midgard/mali_kbase_core_linux.c
@@ -3026,6 +3026,9 @@ static int power_control_init(struct platform_device *pdev)
                        goto fail;
                }
        }
+       kbdev->freq = 0;
+       mutex_init(&kbdev->mutex_for_clk);
+       kbdev->is_power_off = false;
 
 #if defined(CONFIG_OF) && defined(CONFIG_PM_OPP)
        /* Register the OPPs if they are available in device tree */

diff --git a/drivers/gpu/arm/midgard/mali_kbase_defs.h b/drivers/gpu/arm/midgard/mali_kbase_defs.h
index 4bb8c2c7aec23176a4208809a58a087fe4936025..f5775bcbb24887896f8d392fbffb1176e4649ec1 100644 (file)
--- a/drivers/gpu/arm/midgard/mali_kbase_defs.h
+++ b/drivers/gpu/arm/midgard/mali_kbase_defs.h
@@ -912,6 +912,17 @@ struct kbase_device {
        } irqs[3];
 
        struct clk *clock;
+
+       /*
+        * current freq of clk_gpu, in Hz.
+        */
+       unsigned long freq;
+       /*
+        * mutex for setting freq of clk_gpu.
+        */
+       struct mutex mutex_for_clk;
+       bool is_power_off;
+
 #ifdef CONFIG_REGULATOR
        struct regulator *regulator;
 #endif