From patchwork Sat Oct 6 14:16:04 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [U-Boot,1/1] ipu common: reset ipuv3 correctly From: Liu Ying X-Patchwork-Id: 189755 Message-Id: <1349532964-8480-1-git-send-email-Ying.liu@freescale.com> To: Cc: fabio.estevam@freescale.com, liu.y.victor@gmail.com, Liu Ying , u-boot@lists.denx.de Date: Sat, 6 Oct 2012 22:16:04 +0800 From: Liu Ying This patch checks self-clear sw_ipu_rst bit in SCR register of SRC controller to be cleared after setting it to high to reset IPUv3. This makes sure that IPUv3 finishes sofware reset. A timeout mechanism is added to stop polling on the bit status in case the bit could not be cleared by the hardware automatically within 10 millisecond. Signed-off-by: Liu Ying --- drivers/video/ipu_common.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/drivers/video/ipu_common.c b/drivers/video/ipu_common.c index 2020da9..fcc1745 100644 --- a/drivers/video/ipu_common.c +++ b/drivers/video/ipu_common.c @@ -94,6 +94,7 @@ struct ipu_ch_param { temp1; \ }) +#define IPU_SW_RST_TOUT_USEC (10000) void clk_enable(struct clk *clk) { @@ -392,11 +393,20 @@ void ipu_reset(void) { u32 *reg; u32 value; + int timeout = IPU_SW_RST_TOUT_USEC; reg = (u32 *)SRC_BASE_ADDR; value = __raw_readl(reg); value = value | SW_IPU_RST; __raw_writel(value, reg); + + while (__raw_readl(reg) & SW_IPU_RST) { + udelay(1); + if (!(timeout--)) { + printf("ipu software reset timeout\n"); + break; + } + }; } /*