[PATCH v2 04/15] drm/mxsfb: Reset vital register for a proper initialization

From: Robert Chiras
Date: Wed Aug 14 2019 - 06:50:07 EST


Some of the regiters need, like LCDC_CTRL and CTRL2_OUTSTANDING_REQS
needs to be properly cleared and initialized for a better start and stop
routine.

Signed-off-by: Robert Chiras <robert.chiras@xxxxxxx>
---
drivers/gpu/drm/mxsfb/mxsfb_crtc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
index b69ace8..5e44f57 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_crtc.c
@@ -127,6 +127,10 @@ 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)
+ writel(CTRL2_OUTSTANDING_REQS(REQ_16),
+ 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);

@@ -136,12 +140,19 @@ static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
writel(reg, mxsfb->base + LCDC_VDCTRL4);

writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_SET);
+ writel(CTRL1_RECOVERY_ON_UNDERFLOW, mxsfb->base + LCDC_CTRL1 + REG_SET);
}

static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
{
u32 reg;

+ 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);
+
/*
* Even if we disable the controller here, it will still continue
* until its FIFOs are running out of data
@@ -295,6 +306,7 @@ void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
dma_addr_t paddr;

mxsfb_enable_axi_clk(mxsfb);
+ writel(0, mxsfb->base + LCDC_CTRL);
mxsfb_crtc_mode_set_nofb(mxsfb);

/* Write cur_buf as well to avoid an initial corrupt frame */
--
2.7.4