[PATCH v2] ARM: mx28: clock-mx28: Use a proper timeout mechanism
Fabio Estevam
fabio.estevam at freescale.com
Fri Jan 27 09:42:04 EST 2012
Introduce a function for checking the busy bits of CLKCTRL register that
uses a proper timeout mechanism.
Remove parts of code that use busy loops and replace them with the
mxs_clkctrl_timeout() function.
Tested on a mx28evk by performing audio playback.
Suggested-by: Wolfram Sang <w.sang at pengutronix.de>
Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
---
Changes since v1:
- Removed empty lines
- Removed _func_ from error message
- Put mxs_clkctrl_timeout in common file
- Change mx23 too
- Fixed comment about jiffy
arch/arm/mach-mxs/clock-mx23.c | 34 +++------------------
arch/arm/mach-mxs/clock-mx28.c | 49 ++++---------------------------
arch/arm/mach-mxs/include/mach/common.h | 2 +
arch/arm/mach-mxs/system.c | 16 ++++++++++
4 files changed, 29 insertions(+), 72 deletions(-)
diff --git a/arch/arm/mach-mxs/clock-mx23.c b/arch/arm/mach-mxs/clock-mx23.c
index e12e112..293958b 100644
--- a/arch/arm/mach-mxs/clock-mx23.c
+++ b/arch/arm/mach-mxs/clock-mx23.c
@@ -223,7 +223,6 @@ static int cpu_clk_set_rate(struct clk *clk, unsigned long rate)
{
u32 reg, bm_busy, div_max, d, f, div, frac;
unsigned long diff, parent_rate, calc_rate;
- int i;
parent_rate = clk_get_rate(clk->parent);
@@ -275,14 +274,7 @@ static int cpu_clk_set_rate(struct clk *clk, unsigned long rate)
reg |= div << BP_CLKCTRL_CPU_DIV_CPU;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_CPU);
- for (i = 10000; i; i--)
- if (!(__raw_readl(CLKCTRL_BASE_ADDR +
- HW_CLKCTRL_CPU) & bm_busy))
- break;
- if (!i) {
- pr_err("%s: divider writing timeout\n", __func__);
- return -ETIMEDOUT;
- }
+ mxs_clkctrl_timeout(HW_CLKCTRL_CPU, bm_busy);
return 0;
}
@@ -292,7 +284,6 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
{ \
u32 reg, div_max, div; \
unsigned long parent_rate; \
- int i; \
\
parent_rate = clk_get_rate(clk->parent); \
div_max = BM_CLKCTRL_##dr##_DIV >> BP_CLKCTRL_##dr##_DIV; \
@@ -310,15 +301,7 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
} \
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr); \
\
- for (i = 10000; i; i--) \
- if (!(__raw_readl(CLKCTRL_BASE_ADDR + \
- HW_CLKCTRL_##dr) & BM_CLKCTRL_##dr##_BUSY)) \
- break; \
- if (!i) { \
- pr_err("%s: divider writing timeout\n", __func__); \
- return -ETIMEDOUT; \
- } \
- \
+ mxs_clkctrl_timeout(HW_CLKCTRL_##dr, BM_CLKCTRL_##dr##_BUSY); \
return 0; \
}
@@ -461,7 +444,7 @@ static struct clk_lookup lookups[] = {
static int clk_misc_init(void)
{
u32 reg;
- int i;
+ int ret;
/* Fix up parent per register setting */
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ);
@@ -510,14 +493,7 @@ static int clk_misc_init(void)
reg |= 3 << BP_CLKCTRL_HBUS_DIV;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
- for (i = 10000; i; i--)
- if (!(__raw_readl(CLKCTRL_BASE_ADDR +
- HW_CLKCTRL_HBUS) & BM_CLKCTRL_HBUS_BUSY))
- break;
- if (!i) {
- pr_err("%s: divider writing timeout\n", __func__);
- return -ETIMEDOUT;
- }
+ ret = mxs_clkctrl_timeout(HW_CLKCTRL_HBUS, BM_CLKCTRL_HBUS_BUSY);
/* Gate off cpu clock in WFI for power saving */
__raw_writel(BM_CLKCTRL_CPU_INTERRUPT_WAIT,
@@ -532,7 +508,7 @@ static int clk_misc_init(void)
reg |= 30 << BP_CLKCTRL_FRAC_IOFRAC;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC);
- return 0;
+ return ret;
}
int __init mx23_clocks_init(void)
diff --git a/arch/arm/mach-mxs/clock-mx28.c b/arch/arm/mach-mxs/clock-mx28.c
index 5d68e41..f91b8fb 100644
--- a/arch/arm/mach-mxs/clock-mx28.c
+++ b/arch/arm/mach-mxs/clock-mx28.c
@@ -322,7 +322,6 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
{ \
u32 reg, bm_busy, div_max, d, f, div, frac; \
unsigned long diff, parent_rate, calc_rate; \
- int i; \
\
div_max = BM_CLKCTRL_##dr##_DIV >> BP_CLKCTRL_##dr##_DIV; \
bm_busy = BM_CLKCTRL_##dr##_BUSY; \
@@ -396,16 +395,7 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
} \
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr); \
\
- for (i = 10000; i; i--) \
- if (!(__raw_readl(CLKCTRL_BASE_ADDR + \
- HW_CLKCTRL_##dr) & bm_busy)) \
- break; \
- if (!i) { \
- pr_err("%s: divider writing timeout\n", __func__); \
- return -ETIMEDOUT; \
- } \
- \
- return 0; \
+ return mxs_clkctrl_timeout(HW_CLKCTRL_##dr, bm_busy); \
}
_CLK_SET_RATE(cpu_clk, CPU, FRAC0, CPU)
@@ -421,7 +411,6 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
{ \
u32 reg, div_max, div; \
unsigned long parent_rate; \
- int i; \
\
parent_rate = clk_get_rate(clk->parent); \
div_max = BM_CLKCTRL_##dr##_DIV >> BP_CLKCTRL_##dr##_DIV; \
@@ -439,16 +428,7 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
} \
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##dr); \
\
- for (i = 10000; i; i--) \
- if (!(__raw_readl(CLKCTRL_BASE_ADDR + \
- HW_CLKCTRL_##dr) & BM_CLKCTRL_##dr##_BUSY)) \
- break; \
- if (!i) { \
- pr_err("%s: divider writing timeout\n", __func__); \
- return -ETIMEDOUT; \
- } \
- \
- return 0; \
+ return mxs_clkctrl_timeout(HW_CLKCTRL_##dr, BM_CLKCTRL_##dr##_BUSY);\
}
_CLK_SET_RATE1(xbus_clk, XBUS)
@@ -461,7 +441,6 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
u32 reg; \
u64 lrate; \
unsigned long parent_rate; \
- int i; \
\
parent_rate = clk_get_rate(clk->parent); \
if (rate > parent_rate) \
@@ -479,16 +458,7 @@ static int name##_set_rate(struct clk *clk, unsigned long rate) \
reg |= div << BP_CLKCTRL_##rs##_DIV; \
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_##rs); \
\
- for (i = 10000; i; i--) \
- if (!(__raw_readl(CLKCTRL_BASE_ADDR + \
- HW_CLKCTRL_##rs) & BM_CLKCTRL_##rs##_BUSY)) \
- break; \
- if (!i) { \
- pr_err("%s: divider writing timeout\n", __func__); \
- return -ETIMEDOUT; \
- } \
- \
- return 0; \
+ return mxs_clkctrl_timeout(HW_CLKCTRL_##rs, BM_CLKCTRL_##rs##_BUSY);\
}
_CLK_SET_RATE_SAIF(saif0_clk, SAIF0)
@@ -676,7 +646,7 @@ static struct clk_lookup lookups[] = {
static int clk_misc_init(void)
{
u32 reg;
- int i;
+ int ret;
/* Fix up parent per register setting */
reg = __raw_readl(CLKCTRL_BASE_ADDR + HW_CLKCTRL_CLKSEQ);
@@ -756,14 +726,7 @@ static int clk_misc_init(void)
reg |= 3 << BP_CLKCTRL_HBUS_DIV;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_HBUS);
- for (i = 10000; i; i--)
- if (!(__raw_readl(CLKCTRL_BASE_ADDR +
- HW_CLKCTRL_HBUS) & BM_CLKCTRL_HBUS_ASM_BUSY))
- break;
- if (!i) {
- pr_err("%s: divider writing timeout\n", __func__);
- return -ETIMEDOUT;
- }
+ ret = mxs_clkctrl_timeout(HW_CLKCTRL_HBUS, BM_CLKCTRL_HBUS_ASM_BUSY);
/* Gate off cpu clock in WFI for power saving */
__raw_writel(BM_CLKCTRL_CPU_INTERRUPT_WAIT,
@@ -790,7 +753,7 @@ static int clk_misc_init(void)
reg |= 30 << BP_CLKCTRL_FRAC0_IO0FRAC;
__raw_writel(reg, CLKCTRL_BASE_ADDR + HW_CLKCTRL_FRAC0);
- return 0;
+ return ret;
}
int __init mx28_clocks_init(void)
diff --git a/arch/arm/mach-mxs/include/mach/common.h b/arch/arm/mach-mxs/include/mach/common.h
index e1237ab..c50c3ea 100644
--- a/arch/arm/mach-mxs/include/mach/common.h
+++ b/arch/arm/mach-mxs/include/mach/common.h
@@ -31,4 +31,6 @@ extern void mx28_init_irq(void);
extern void icoll_init_irq(void);
+extern int mxs_clkctrl_timeout(unsigned int reg_offset, unsigned int mask);
+
#endif /* __MACH_MXS_COMMON_H__ */
diff --git a/arch/arm/mach-mxs/system.c b/arch/arm/mach-mxs/system.c
index 54f91ad..98e2de0 100644
--- a/arch/arm/mach-mxs/system.c
+++ b/arch/arm/mach-mxs/system.c
@@ -37,6 +37,8 @@
#define MXS_MODULE_CLKGATE (1 << 30)
#define MXS_MODULE_SFTRST (1 << 31)
+#define CLKCTRL_TIMEOUT 10 /* 10 ms */
+
static void __iomem *mxs_clkctrl_reset_addr;
/*
@@ -137,3 +139,17 @@ error:
return -ETIMEDOUT;
}
EXPORT_SYMBOL(mxs_reset_block);
+
+int mxs_clkctrl_timeout(unsigned int reg_offset, unsigned int mask)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(CLKCTRL_TIMEOUT);
+ while (readl_relaxed(MXS_IO_ADDRESS(MXS_CLKCTRL_BASE_ADDR)
+ + reg_offset) & mask) {
+ if (time_after(jiffies, timeout)) {
+ pr_err("Timeout at CLKCTRL + 0x%x\n", reg_offset);
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
--
1.7.1
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