From 3d6e614952e3e4cf9e70e58893a740ffec220b24 Mon Sep 17 00:00:00 2001 From: "Hans J. Koch" Date: Thu, 12 Aug 2010 15:10:53 +0200 Subject: mx35: Fix boot ROM hang in internal boot mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If a watchdog reset occurs after booting in internal boot mode, the i.MX35 won't boot anymore. The boot ROM code seems to assume that some clocks are turned on (they are after a power-on reset). This patch turns on the necessary clocks. Signed-off-by: Hans J. Koch Acked-by: Uwe Kleine-König Reported-by: John Ogness Signed-off-by: Sascha Hauer --- arch/arm/mach-mx3/clock-imx35.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) (limited to 'arch/arm/mach-mx3/clock-imx35.c') diff --git a/arch/arm/mach-mx3/clock-imx35.c b/arch/arm/mach-mx3/clock-imx35.c index d3af0fdf847..32adf8d5b1f 100644 --- a/arch/arm/mach-mx3/clock-imx35.c +++ b/arch/arm/mach-mx3/clock-imx35.c @@ -485,10 +485,10 @@ static struct clk_lookup lookups[] = { int __init mx35_clocks_init() { - unsigned int ll = 0; + unsigned int cgr2 = 3 << 26, cgr3 = 0; #if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_ICEDCC) - ll = (3 << 16); + cgr2 |= 3 << 16; #endif clkdev_add_table(lookups, ARRAY_SIZE(lookups)); @@ -499,8 +499,20 @@ int __init mx35_clocks_init() __raw_writel((3 << 18), CCM_BASE + CCM_CGR0); __raw_writel((3 << 2) | (3 << 4) | (3 << 6) | (3 << 8) | (3 << 16), CCM_BASE + CCM_CGR1); - __raw_writel((3 << 26) | ll, CCM_BASE + CCM_CGR2); - __raw_writel(0, CCM_BASE + CCM_CGR3); + + /* + * Check if we came up in internal boot mode. If yes, we need some + * extra clocks turned on, otherwise the MX35 boot ROM code will + * hang after a watchdog reset. + */ + if (!(__raw_readl(CCM_BASE + CCM_RCSR) & (3 << 10))) { + /* Additionally turn on UART1, SCC, and IIM clocks */ + cgr2 |= 3 << 16 | 3 << 4; + cgr3 |= 3 << 2; + } + + __raw_writel(cgr2, CCM_BASE + CCM_CGR2); + __raw_writel(cgr3, CCM_BASE + CCM_CGR3); mxc_timer_init(&gpt_clk, MX35_IO_ADDRESS(MX35_GPT1_BASE_ADDR), MX35_INT_GPT); -- cgit v1.2.3-18-g5258