[PATCH 08/11] drm/mxsfb: Update mxsfb to support LCD reset

[Robert Chiras <robert.chiras@nxp.com>]

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 | 10 ++++++++--
 drivers/gpu/drm/mxsfb/mxsfb_regs.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index b1d0267..35d6f10 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -230,9 +230,12 @@ 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);
@@ -250,9 +253,12 @@ static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 {
 	u32 reg;
 
-	if (mxsfb->devdata->ipversion >= 4)
+	if (mxsfb->devdata->ipversion >= 4) {
 		writel(CTRL2_OUTSTANDING_REQS(0x7),
 			mxsfb->base + LCDC_V4_CTRL2 + REG_CLR);
+		/* De-assert LCD Reset bit */
+		writel(CTRL2_LCD_RESET, mxsfb->base + LCDC_V4_CTRL2 + REG_CLR);
+	}
 
 	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_CLR);
 
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_regs.h b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
index 4904fdd..1d85750 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_regs.h
+++ b/drivers/gpu/drm/mxsfb/mxsfb_regs.h
@@ -95,6 +95,7 @@
 #define CTRL2_OUTSTANDING_REQS(x)	REG_PUT((x), 23, 21)
 #define CTRL2_ODD_LINE_PATTERN(x)	REG_PUT((x), 18, 16)
 #define CTRL2_EVEN_LINE_PATTERN(x)	REG_PUT((x), 14, 12)
+#define CTRL2_LCD_RESET			BIT(0)
 
 #define TRANSFER_COUNT_SET_VCOUNT(x)	(((x) & 0xffff) << 16)
 #define TRANSFER_COUNT_GET_VCOUNT(x)	(((x) >> 16) & 0xffff)
-- 
2.7.4