commit 5f8dbf538d42c5ef74ae8e383632d50204ed0012
author Peng Fan <Peng.Fan@freescale.com> Thu Oct 29 15:54:49 2015 +0800
committer Stefano Babic <sbabic@denx.de> Thu Nov 12 17:40:53 2015 +0100
tree 664654ac167352c938555136dcb670e90ec04099
parent 60c72b65ce3218a3d1dd993f9a845e9aff9946b5

video: mxsfb: introduce lcdif_power_down

Introudce a new function lcdif_power_down.

1. Waits for a VSYNC interrupt to guarantee the reset is done at the
   VSYNC edge, which somehow makes the LCDIF consume the display FIFO(?)
   and helps the LCDIF work normally at the kernel stage.
2. Add power down function to stop lcdif.

The reason to introduce lcdif_power_down is that we want lcdif to be in
initial state when doing uboot reset or before kernel boot to make
system stable, otherwise system may hang.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Acked-by: Anatolij Gustschin <agust@denx.de>

drivers/video/mxsfb.c

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index eed57d5..ddbb118 100644
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -131,6 +131,23 @@
 	writel(LCDIF_CTRL_RUN, &regs->hw_lcdif_ctrl_set);
 }
 
+void lcdif_power_down(void)
+{
+	struct mxs_lcdif_regs *regs = (struct mxs_lcdif_regs *)MXS_LCDIF_BASE;
+	int timeout = 1000000;
+
+	writel(panel.frameAdrs, &regs->hw_lcdif_cur_buf_reg);
+	writel(panel.frameAdrs, &regs->hw_lcdif_next_buf_reg);
+	writel(LCDIF_CTRL1_VSYNC_EDGE_IRQ, &regs->hw_lcdif_ctrl1_clr);
+	while (--timeout) {
+		if (readl(&regs->hw_lcdif_ctrl1_reg) &
+		    LCDIF_CTRL1_VSYNC_EDGE_IRQ)
+			break;
+		udelay(1);
+	}
+	mxs_reset_block((struct mxs_register_32 *)&regs->hw_lcdif_ctrl_reg);
+}
+
 void *video_hw_init(void)
 {
 	int bpp = -1;