[PATCH] drm/stm: add sleep power management

From: Yannick FertrÃ
Date: Thu Mar 21 2019 - 04:16:05 EST


Implements system sleep power management ops.

Signed-off-by: Yannick Fertrà <yannick.fertre@xxxxxx>
---
drivers/gpu/drm/stm/drv.c | 35 +++++++++++++++++++++++++++++++++++
drivers/gpu/drm/stm/ltdc.c | 24 ++++++++++++++++++++++++
drivers/gpu/drm/stm/ltdc.h | 3 +++
3 files changed, 62 insertions(+)

diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
index 0a7f933..5834ef5 100644
--- a/drivers/gpu/drm/stm/drv.c
+++ b/drivers/gpu/drm/stm/drv.c
@@ -129,6 +129,40 @@ static void drv_unload(struct drm_device *ddev)
drm_mode_config_cleanup(ddev);
}

+static __maybe_unused int drv_suspend(struct device *dev)
+{
+ struct drm_device *ddev = dev_get_drvdata(dev);
+ struct ltdc_device *ldev = ddev->dev_private;
+ struct drm_atomic_state *state;
+
+ drm_kms_helper_poll_disable(ddev);
+ state = drm_atomic_helper_suspend(ddev);
+ if (IS_ERR(state)) {
+ drm_kms_helper_poll_enable(ddev);
+ return PTR_ERR(state);
+ }
+ ldev->suspend_state = state;
+ ltdc_suspend(ddev);
+
+ return 0;
+}
+
+static __maybe_unused int drv_resume(struct device *dev)
+{
+ struct drm_device *ddev = dev_get_drvdata(dev);
+ struct ltdc_device *ldev = ddev->dev_private;
+
+ ltdc_resume(ddev);
+ drm_atomic_helper_resume(ddev, ldev->suspend_state);
+ drm_kms_helper_poll_enable(ddev);
+
+ return 0;
+}
+
+static const struct dev_pm_ops drv_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(drv_suspend, drv_resume)
+};
+
static int stm_drm_platform_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -186,6 +220,7 @@ static struct platform_driver stm_drm_platform_driver = {
.driver = {
.name = "stm32-display",
.of_match_table = drv_dt_ids,
+ .pm = &drv_pm_ops,
},
};

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index b1741a9..32fd6a3 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1062,6 +1062,30 @@ static int ltdc_get_caps(struct drm_device *ddev)
return 0;
}

+void ltdc_suspend(struct drm_device *ddev)
+{
+ struct ltdc_device *ldev = ddev->dev_private;
+
+ DRM_DEBUG_DRIVER("\n");
+ clk_disable_unprepare(ldev->pixel_clk);
+}
+
+int ltdc_resume(struct drm_device *ddev)
+{
+ struct ltdc_device *ldev = ddev->dev_private;
+ int ret;
+
+ DRM_DEBUG_DRIVER("\n");
+
+ ret = clk_prepare_enable(ldev->pixel_clk);
+ if (ret) {
+ DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
int ltdc_load(struct drm_device *ddev)
{
struct platform_device *pdev = to_platform_device(ddev->dev);
diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
index e46f477..a1ad0ae 100644
--- a/drivers/gpu/drm/stm/ltdc.h
+++ b/drivers/gpu/drm/stm/ltdc.h
@@ -36,6 +36,7 @@ struct ltdc_device {
u32 error_status;
u32 irq_status;
struct fps_info plane_fpsi[LTDC_MAX_LAYER];
+ struct drm_atomic_state *suspend_state;
};

bool ltdc_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,
@@ -45,5 +46,7 @@ bool ltdc_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe,

int ltdc_load(struct drm_device *ddev);
void ltdc_unload(struct drm_device *ddev);
+void ltdc_suspend(struct drm_device *ddev);
+int ltdc_resume(struct drm_device *ddev);

#endif
--
2.7.4