From patchwork Mon Jan 23 14:41:07 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: ARM: mx28: clock-mx28: Use a proper timeout mechanism Date: Mon, 23 Jan 2012 04:41:07 -0000 From: Fabio Estevam X-Patchwork-Id: 137365 Message-Id: <1327329667-25512-1-git-send-email-fabio.estevam@freescale.com> To: Cc: Fabio Estevam , shawn.guo@freescale.com, kernel@pengutronix.de 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 Signed-off-by: Fabio Estevam --- arch/arm/mach-mxs/clock-mx28.c | 64 +++++++++++++--------------------------- 1 files changed, 21 insertions(+), 43 deletions(-) diff --git a/arch/arm/mach-mxs/clock-mx28.c b/arch/arm/mach-mxs/clock-mx28.c index 5d68e41..ad5482d 100644 --- a/arch/arm/mach-mxs/clock-mx28.c +++ b/arch/arm/mach-mxs/clock-mx28.c @@ -38,6 +38,7 @@ #define DIGCTRL_BASE_ADDR MX28_IO_ADDRESS(MX28_DIGCTL_BASE_ADDR) #define PARENT_RATE_SHIFT 8 +#define CLKCTRL_TIMEOUT 10 /* 10 ms = 1 jiffy */ static struct clk pll2_clk; static struct clk cpu_clk; @@ -127,6 +128,20 @@ static unsigned long pll2_clk_get_rate(struct clk *clk) return 50000000; } +static int mxs_clkctrl_timeout(unsigned int reg_offset, unsigned int mask) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(CLKCTRL_TIMEOUT); + while (readl_relaxed(CLKCTRL_BASE_ADDR + reg_offset) & mask) { + if (time_after(jiffies, timeout)) { + pr_err("%s: divider writing timeout\n", __func__); + return -ETIMEDOUT; + } + + } + + return 0; +} + #define _CLK_ENABLE_PLL(name, r, g) \ static int name##_enable(struct clk *clk) \ { \ @@ -322,7 +337,6 @@ 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 +410,7 @@ 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 +426,6 @@ 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 +443,7 @@ 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 +456,6 @@ 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 +473,7 @@ 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 +661,7 @@ 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 +741,7 @@ 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 +768,7 @@ 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)