[PATCH 4/5] drm/tinydrm/mi0283qt: Let the display pipe handle power

[Noralf Trønnes]

It's better to leave power handling and controller init to the
modesetting machinery using the simple pipe .enable and .disable
callbacks.

Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
---
 drivers/gpu/drm/tinydrm/mi0283qt.c | 51 ++++++++------------------------------
 drivers/gpu/drm/tinydrm/mipi-dbi.c | 14 ++++++-----
 2 files changed, 19 insertions(+), 46 deletions(-)

diff --git a/drivers/gpu/drm/tinydrm/mi0283qt.c b/drivers/gpu/drm/tinydrm/mi0283qt.c
index 5994140f1e1e..8318a60e584c 100644
--- a/drivers/gpu/drm/tinydrm/mi0283qt.c
+++ b/drivers/gpu/drm/tinydrm/mi0283qt.c
@@ -47,9 +47,11 @@
 #define ILI9341_MADCTL_MX	BIT(6)
 #define ILI9341_MADCTL_MY	BIT(7)
 
-static int mi0283qt_init(struct mipi_dbi *mipi)
+static void mi0283qt_enable(struct drm_simple_display_pipe *pipe,
+			    struct drm_crtc_state *crtc_state)
 {
-	struct tinydrm_device *tdev = &mipi->tinydrm;
+	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 	struct device *dev = tdev->drm->dev;
 	u8 addr_mode;
 	int ret;
@@ -59,19 +61,18 @@ static int mi0283qt_init(struct mipi_dbi *mipi)
 	ret = regulator_enable(mipi->regulator);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Failed to enable regulator: %d\n", ret);
-		return ret;
+		return;
 	}
 
-	/* Avoid flicker by skipping setup if the bootloader has done it */
 	if (mipi_dbi_display_is_on(mipi))
-		return 0;
+		goto out_enable;
 
 	mipi_dbi_hw_reset(mipi);
 	ret = mipi_dbi_command(mipi, MIPI_DCS_SOFT_RESET);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "Error sending command: %d\n", ret);
 		regulator_disable(mipi->regulator);
-		return ret;
+		return;
 	}
 
 	msleep(20);
@@ -137,19 +138,12 @@ static int mi0283qt_init(struct mipi_dbi *mipi)
 	mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
 	msleep(100);
 
-	return 0;
-}
-
-static void mi0283qt_fini(void *data)
-{
-	struct mipi_dbi *mipi = data;
-
-	DRM_DEBUG_KMS("\n");
-	regulator_disable(mipi->regulator);
+out_enable:
+	mipi_dbi_pipe_enable(pipe, crtc_state);
 }
 
 static const struct drm_simple_display_pipe_funcs mi0283qt_pipe_funcs = {
-	.enable = mipi_dbi_pipe_enable,
+	.enable = mi0283qt_enable,
 	.disable = mipi_dbi_pipe_disable,
 	.update = tinydrm_display_pipe_update,
 	.prepare_fb = tinydrm_display_pipe_prepare_fb,
@@ -230,17 +224,6 @@ static int mi0283qt_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
-	ret = mi0283qt_init(mipi);
-	if (ret)
-		return ret;
-
-	/* use devres to fini after drm unregister (drv->remove is before) */
-	ret = devm_add_action(dev, mi0283qt_fini, mipi);
-	if (ret) {
-		mi0283qt_fini(mipi);
-		return ret;
-	}
-
 	spi_set_drvdata(spi, mipi);
 
 	return devm_tinydrm_register(&mipi->tinydrm);
@@ -256,25 +239,13 @@ static void mi0283qt_shutdown(struct spi_device *spi)
 static int __maybe_unused mi0283qt_pm_suspend(struct device *dev)
 {
 	struct mipi_dbi *mipi = dev_get_drvdata(dev);
-	int ret;
 
-	ret = drm_mode_config_helper_suspend(mipi->tinydrm.drm);
-	if (ret)
-		return ret;
-
-	mi0283qt_fini(mipi);
-
-	return 0;
+	return drm_mode_config_helper_suspend(mipi->tinydrm.drm);
 }
 
 static int __maybe_unused mi0283qt_pm_resume(struct device *dev)
 {
 	struct mipi_dbi *mipi = dev_get_drvdata(dev);
-	int ret;
-
-	ret = mi0283qt_init(mipi);
-	if (ret)
-		return ret;
 
 	drm_mode_config_helper_resume(mipi->tinydrm.drm);
 
diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c b/drivers/gpu/drm/tinydrm/mipi-dbi.c
index aa6b6ce56891..5b5ed68d8994 100644
--- a/drivers/gpu/drm/tinydrm/mipi-dbi.c
+++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c
@@ -275,8 +275,9 @@ static const struct drm_framebuffer_funcs mipi_dbi_fb_funcs = {
  * @pipe: Display pipe
  * @crtc_state: CRTC state
  *
- * This function enables backlight. Drivers can use this as their
- * &drm_simple_display_pipe_funcs->enable callback.
+ * This function flushes the whole framebuffer and enables the backlight.
+ * Drivers can use this in their &drm_simple_display_pipe_funcs->enable
+ * callback.
  */
 void mipi_dbi_pipe_enable(struct drm_simple_display_pipe *pipe,
 			  struct drm_crtc_state *crtc_state)
@@ -285,8 +286,6 @@ void mipi_dbi_pipe_enable(struct drm_simple_display_pipe *pipe,
 	struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
 	struct drm_framebuffer *fb = pipe->plane.fb;
 
-	DRM_DEBUG_KMS("\n");
-
 	mipi->enabled = true;
 	if (fb)
 		fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
@@ -316,8 +315,8 @@ static void mipi_dbi_blank(struct mipi_dbi *mipi)
  * mipi_dbi_pipe_disable - MIPI DBI pipe disable helper
  * @pipe: Display pipe
  *
- * This function disables backlight if present or if not the
- * display memory is blanked. Drivers can use this as their
+ * This function disables backlight if present, if not the display memory is
+ * blanked. The regulator is disabled if in use. Drivers can use this as their
  * &drm_simple_display_pipe_funcs->disable callback.
  */
 void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe)
@@ -333,6 +332,9 @@ void mipi_dbi_pipe_disable(struct drm_simple_display_pipe *pipe)
 		tinydrm_disable_backlight(mipi->backlight);
 	else
 		mipi_dbi_blank(mipi);
+
+	if (mipi->regulator)
+		regulator_disable(mipi->regulator);
 }
 EXPORT_SYMBOL(mipi_dbi_pipe_disable);
 
-- 
2.14.2