Thread (22 messages) 22 messages, 5 authors, 2019-08-28
STALE2485d
Revisions (3)
  1. v2 [diff vs current]
  2. v3 current
  3. v4 [diff vs current]

[PATCH v3 11/15] drm/mxsfb: Update mxsfb to support LCD reset

From: Robert Chiras <robert.chiras@nxp.com>
Date: 2019-08-21 10:16:30
Also in: dri-devel, linux-devicetree, lkml
Subsystem: drm drivers, drm drivers and misc gpu patches, mxsfb drm driver, the rest · Maintainers: David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Marek Vasut, Stefan Agner, Linus Torvalds

The eLCDIF controller has control pin for the external LCD reset pin.
Add support for it and assert this pin in enable and de-assert it in
disable.

Signed-off-by: Robert Chiras <robert.chiras@nxp.com>
---
 drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 14 ++++++++++----
 drivers/gpu/drm/mxsfb/mxsfb_regs.h |  2 ++
 2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index 1be29f5..a4ba368 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -224,9 +224,12 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
 		clk_prepare_enable(mxsfb->clk_disp_axi);
 	clk_prepare_enable(mxsfb->clk);
 
-	if (mxsfb->devdata->ipversion >= 4)
+	if (mxsfb->devdata->ipversion >= 4) {
 		writel(CTRL2_OUTSTANDING_REQS(REQ_16),
 		       mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
+		/* Assert LCD Reset bit */
+		writel(CTRL2_LCD_RESET, mxsfb->base + LCDC_V4_CTRL2 + REG_SET);
+	}
 
 	/* If it was disabled, re-enable the mode again */
 	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);
@@ -244,11 +247,14 @@ static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 {
 	u32 reg;
 
-	if (mxsfb->devdata->ipversion >= 4)
+	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_CLR);
+
+	if (mxsfb->devdata->ipversion >= 4) {
 		writel(CTRL2_OUTSTANDING_REQS(0x7),
 		       mxsfb->base + LCDC_V4_CTRL2 + REG_CLR);
-
-	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_CLR);
+		/* De-assert LCD Reset bit */
+		writel(CTRL2_LCD_RESET, mxsfb->base + LCDC_V4_CTRL2 + REG_CLR);
+	}
 
 	/*
 	 * Even if we disable the controller here, it will still continue
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_regs.h b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
index dc4daa0..0f63ba1 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_regs.h
+++ b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
@@ -108,6 +108,8 @@
 #define CTRL2_LINE_PATTERN_BGR	5
 #define CTRL2_LINE_PATTERN_CLR	7
 
+#define CTRL2_LCD_RESET			BIT(0)
+
 #define TRANSFER_COUNT_SET_VCOUNT(x)	REG_PUT((x), 31, 16)
 #define TRANSFER_COUNT_GET_VCOUNT(x)	REG_GET((x), 31, 16)
 #define TRANSFER_COUNT_SET_HCOUNT(x)	REG_PUT((x), 15, 0)
-- 
2.7.4


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