diff options
| author | Michel Jaouen <michel.jaouen@stericsson.com> | 2012-08-31 14:21:30 +0200 |
|---|---|---|
| committer | Samuel Ortiz <sameo@linux.intel.com> | 2012-09-23 20:51:34 +0200 |
| commit | 804971ec3793d30f40c1a74775dd3fe89deb461a (patch) | |
| tree | edec886d66c3b2b02c4030cb679d730156abe2e2 /drivers/mfd/db8500-prcmu.c | |
| parent | 0dd96360e21ec7963aeba253261db87a32e728c6 (diff) | |
mfd: dbx500: Provide a more accurate smp_twd clock
The local timer clock is based on ARM subsystem clock. This patch
obtains a more exact value of that clock by reading PRCMU registers.
Using this increases the accuracy of the local timer events.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com>
Signed-off-by: Michel Jaouen <michel.jaouen@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/mfd/db8500-prcmu.c')
| -rw-r--r-- | drivers/mfd/db8500-prcmu.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c index 0e63cdd9b52a..6fb11b76071e 100644 --- a/drivers/mfd/db8500-prcmu.c +++ b/drivers/mfd/db8500-prcmu.c @@ -418,6 +418,9 @@ static struct { static atomic_t ac_wake_req_state = ATOMIC_INIT(0); +/* Functions definition */ +static void compute_armss_rate(void); + /* Spinlocks */ static DEFINE_SPINLOCK(prcmu_lock); static DEFINE_SPINLOCK(clkout_lock); @@ -1013,6 +1016,7 @@ int db8500_prcmu_set_arm_opp(u8 opp) (mb1_transfer.ack.arm_opp != opp)) r = -EIO; + compute_armss_rate(); mutex_unlock(&mb1_transfer.lock); return r; @@ -1612,6 +1616,7 @@ static unsigned long pll_rate(void __iomem *reg, unsigned long src_rate, if ((branch == PLL_FIX) || ((branch == PLL_DIV) && (val & PRCM_PLL_FREQ_DIV2EN) && ((reg == PRCM_PLLSOC0_FREQ) || + (reg == PRCM_PLLARM_FREQ) || (reg == PRCM_PLLDDR_FREQ)))) div *= 2; @@ -1661,6 +1666,39 @@ static unsigned long clock_rate(u8 clock) else return 0; } +static unsigned long latest_armss_rate; +static unsigned long armss_rate(void) +{ + return latest_armss_rate; +} + +static void compute_armss_rate(void) +{ + u32 r; + unsigned long rate; + + r = readl(PRCM_ARM_CHGCLKREQ); + + if (r & PRCM_ARM_CHGCLKREQ_PRCM_ARM_CHGCLKREQ) { + /* External ARMCLKFIX clock */ + + rate = pll_rate(PRCM_PLLDDR_FREQ, ROOT_CLOCK_RATE, PLL_FIX); + + /* Check PRCM_ARM_CHGCLKREQ divider */ + if (!(r & PRCM_ARM_CHGCLKREQ_PRCM_ARM_DIVSEL)) + rate /= 2; + + /* Check PRCM_ARMCLKFIX_MGT divider */ + r = readl(PRCM_ARMCLKFIX_MGT); + r &= PRCM_CLK_MGT_CLKPLLDIV_MASK; + rate /= r; + + } else {/* ARM PLL */ + rate = pll_rate(PRCM_PLLARM_FREQ, ROOT_CLOCK_RATE, PLL_DIV); + } + + latest_armss_rate = rate; +} static unsigned long dsiclk_rate(u8 n) { @@ -1707,6 +1745,8 @@ unsigned long prcmu_clock_rate(u8 clock) return pll_rate(PRCM_PLLSOC0_FREQ, ROOT_CLOCK_RATE, PLL_RAW); else if (clock == PRCMU_PLLSOC1) return pll_rate(PRCM_PLLSOC1_FREQ, ROOT_CLOCK_RATE, PLL_RAW); + else if (clock == PRCMU_ARMSS) + return armss_rate(); else if (clock == PRCMU_PLLDDR) return pll_rate(PRCM_PLLDDR_FREQ, ROOT_CLOCK_RATE, PLL_RAW); else if (clock == PRCMU_PLLDSI) @@ -2693,6 +2733,7 @@ void __init db8500_prcmu_early_init(void) handle_simple_irq); set_irq_flags(irq, IRQF_VALID); } + compute_armss_rate(); } static void __init init_prcm_registers(void) |