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

From: Robert Chiras
Date: Wed Aug 21 2019 - 06:16:37 EST


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@xxxxxxx>
---
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