Hi Stefano,
On Tue, Oct 20, 2015 at 03:59:18PM +0200, Stefano Babic wrote:
Hi Peng,
On 20/10/2015 13:39, Peng Fan wrote:
Introudce a new function lcdif_power_down.
- 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.
- 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.
The explanation is independent from the processor type. But checking in the next patch, this code runs only for 6UL. Why not for the 6sx ?
We met the issue on i.MX6UL EVK, but did not met issue on i.MX6SX SDB. So I add the check. After a thought, it should be open to CONFIG_VIDEO_MXS.
To those which use LPDDR2 or LPDDR3, if LCDIF is enabled, lcdif_power_down is a must, since there is no reset pin as DDR3. No reset pin will make ddr not stable. Anyway lcdif_power_down do not hurts to those use DDR3.
Will use #ifdef CONFIG_VIDEO_MXS lcdif_power_down(); #endif
Regards, Peng.
Signed-off-by: Peng Fan Peng.Fan@freescale.com Cc: Stefano Babic sbabic@denx.de Cc: Anatolij Gustschin agust@denx.de
V2: none
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 5673fb4..386c2dc 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 eed57d5..ddbb118 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;
Best regards, Stefano Babic
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