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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 <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Juha Yrjola 2006-09-25 12:41:50 +03:00 committed by Tony Lindgren
parent dc0d794e48
commit ddc32a8749
1 changed files with 47 additions and 1 deletions
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48
arch/arm/mach-omap2/clock.c
View File

@ -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;
}