[PATCH v2 5/6] drm/fsl-dcu: implement suspend/resume using atomic helpers

[Stefan Agner]

Use the drm_atomic_helper_suspend() and drm_atomic_helper_resume()
helpers to implement subsystem-level suspend/resume. This replaces
the (non-functional) regmap cache based suspend resume functionality.

Signed-off-by: Stefan Agner <ste...@agner.ch>
---
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 40 ++++++++++++++++++++++++++-----
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h |  1 +
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c 
b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
index 06a4d01..2bc4fa2 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
@@ -11,6 +11,7 @@
 
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/console.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
 #include <linux/mm.h>
@@ -22,6 +23,7 @@
 #include <linux/regmap.h>
 
 #include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
@@ -42,10 +44,8 @@ static const struct regmap_config fsl_dcu_regmap_config = {
        .reg_bits = 32,
        .reg_stride = 4,
        .val_bits = 32,
-       .cache_type = REGCACHE_FLAT,
 
        .volatile_reg = fsl_dcu_drm_is_volatile_reg,
-       .max_register = 0x11fc,
 };
 
 static int fsl_dcu_drm_irq_init(struct drm_device *dev)
@@ -229,9 +229,25 @@ static int fsl_dcu_drm_pm_suspend(struct device *dev)
        if (!fsl_dev)
                return 0;
 
+       disable_irq(fsl_dev->irq);
        drm_kms_helper_poll_disable(fsl_dev->drm);
-       regcache_cache_only(fsl_dev->regmap, true);
-       regcache_mark_dirty(fsl_dev->regmap);
+
+       console_lock();
+       drm_fbdev_cma_set_suspend(fsl_dev->fbdev, 1);
+       console_unlock();
+
+       fsl_dev->state = drm_atomic_helper_suspend(fsl_dev->drm);
+       if (IS_ERR(fsl_dev->state)) {
+               console_lock();
+               drm_fbdev_cma_set_suspend(fsl_dev->fbdev, 0);
+               console_unlock();
+
+               drm_kms_helper_poll_enable(fsl_dev->drm);
+               enable_irq(fsl_dev->irq);
+               return PTR_ERR(fsl_dev->state);
+       }
+
+       clk_disable_unprepare(fsl_dev->pix_clk);
        clk_disable_unprepare(fsl_dev->clk);
 
        return 0;
@@ -251,9 +267,21 @@ static int fsl_dcu_drm_pm_resume(struct device *dev)
                return ret;
        }
 
+       ret = clk_prepare_enable(fsl_dev->pix_clk);
+       if (ret < 0) {
+               dev_err(dev, "failed to enable pix clk\n");
+               return ret;
+       }
+
+       fsl_dcu_drm_init_planes(fsl_dev->drm);
+       drm_atomic_helper_resume(fsl_dev->drm, fsl_dev->state);
+
+       console_lock();
+       drm_fbdev_cma_set_suspend(fsl_dev->fbdev, 0);
+       console_unlock();
+
        drm_kms_helper_poll_enable(fsl_dev->drm);
-       regcache_cache_only(fsl_dev->regmap, false);
-       regcache_sync(fsl_dev->regmap);
+       enable_irq(fsl_dev->irq);
 
        return 0;
 }
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h 
b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
index b1bba3a..3b371fe7 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
@@ -194,6 +194,7 @@ struct fsl_dcu_drm_device {
        struct drm_encoder encoder;
        struct fsl_dcu_drm_connector connector;
        const struct fsl_dcu_soc_data *soc;
+       struct drm_atomic_state *state;
 };
 
 void fsl_dcu_fbdev_init(struct drm_device *dev);
-- 
2.8.2