From a3c252d6d68f9038106e0c11298438a2e50ab50f Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Thu, 29 Oct 2015 15:54:49 +0800 Subject: [PATCH] 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 Cc: Stefano Babic Cc: Anatolij Gustschin Acked-by: Anatolij Gustschin --- arch/arm/include/asm/imx-common/sys_proto.h | 2 ++ drivers/video/mxsfb.c | 17 +++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/arch/arm/include/asm/imx-common/sys_proto.h b/arch/arm/include/asm/imx-common/sys_proto.h index 5673fb4bc1..386c2dc42b 100644 --- a/arch/arm/include/asm/imx-common/sys_proto.h +++ b/arch/arm/include/asm/imx-common/sys_proto.h @@ -47,6 +47,8 @@ int fecmxc_initialize(bd_t *bis); u32 get_ahb_clk(void); u32 get_periph_clk(void); +void lcdif_power_down(void); + int mxs_reset_block(struct mxs_register_32 *reg); int mxs_wait_mask_set(struct mxs_register_32 *reg, u32 mask, u32 timeout); int mxs_wait_mask_clr(struct mxs_register_32 *reg, u32 mask, u32 timeout); diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c index eed57d55c3..ddbb118d70 100644 --- a/drivers/video/mxsfb.c +++ b/drivers/video/mxsfb.c @@ -131,6 +131,23 @@ static void mxs_lcd_init(GraphicDevice *panel, writel(LCDIF_CTRL_RUN, ®s->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, ®s->hw_lcdif_cur_buf_reg); + writel(panel.frameAdrs, ®s->hw_lcdif_next_buf_reg); + writel(LCDIF_CTRL1_VSYNC_EDGE_IRQ, ®s->hw_lcdif_ctrl1_clr); + while (--timeout) { + if (readl(®s->hw_lcdif_ctrl1_reg) & + LCDIF_CTRL1_VSYNC_EDGE_IRQ) + break; + udelay(1); + } + mxs_reset_block((struct mxs_register_32 *)®s->hw_lcdif_ctrl_reg); +} + void *video_hw_init(void) { int bpp = -1; -- 2.39.2