From ddc32a87497d8806e361cfe7168f173396fe9219 Mon Sep 17 00:00:00 2001 From: Juha Yrjola Date: Mon, 25 Sep 2006 12:41:50 +0300 Subject: [PATCH] ARM: OMAP2: Make sure peripherals can be accessed after clk_enable Some peripherals seem to need additional delay until they can actually be accessed after enabling their FCLK and ICLK. Signed-off-by: Juha Yrjola Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/clock.c | 48 ++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c index eee273bdd191..26ac49ecb78d 100644 --- a/arch/arm/mach-omap2/clock.c +++ b/arch/arm/mach-omap2/clock.c @@ -32,6 +32,8 @@ #include "memory.h" #include "clock.h" +#undef DEBUG + //#define DOWN_VARIABLE_DPLL 1 /* Experimental */ static struct prcm_config *curr_prcm_set; @@ -114,11 +116,53 @@ static void omap2_clk_fixed_enable(struct clk *clk) while (!(CM_IDLEST_CKGEN & cval)) { /* Wait for lock */ ++i; udelay(1); - if (i == 100000) + if (i == 100000) { + printk(KERN_ERR "Clock %s didn't lock\n", clk->name); break; + } } } +static void omap2_clk_wait_ready(struct clk *clk) +{ + unsigned long reg, other_reg, st_reg; + u32 bit; + int i; + + reg = (unsigned long) clk->enable_reg; + if (reg == (unsigned long) &CM_FCLKEN1_CORE || + reg == (unsigned long) &CM_FCLKEN2_CORE) + other_reg = (reg & ~0xf0) | 0x10; + else if (reg == (unsigned long) &CM_ICLKEN1_CORE || + reg == (unsigned long) &CM_ICLKEN2_CORE) + other_reg = (reg & ~0xf0) | 0x00; + else + return; + + /* No check for DSS or cam clocks */ + if ((reg & 0x0f) == 0) { + if (clk->enable_bit <= 1 || clk->enable_bit == 31) + return; + } + + /* Check if both functional and interface clocks + * are running. */ + bit = 1 << clk->enable_bit; + if (!(__raw_readl(other_reg) & bit)) + return; + st_reg = (other_reg & ~0xf0) | 0x20; + i = 0; + while (!(__raw_readl(st_reg) & bit)) { + i++; + if (i == 100000) { + printk(KERN_ERR "Timeout enabling clock %s\n", clk->name); + break; + } + } + if (i) + pr_debug("Clock %s stable after %d loops\n", clk->name, i); +} + /* Enables clock without considering parent dependencies or use count * REVISIT: Maybe change this to use clk->enable like on omap1? */ @@ -150,6 +194,8 @@ static int _omap2_clk_enable(struct clk * clk) __raw_writel(regval32, clk->enable_reg); wmb(); + omap2_clk_wait_ready(clk); + return 0; }