From: Michel Jaouen <[email protected]> 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 <[email protected]> Signed-off-by: Rickard Andersson <[email protected]> Signed-off-by: Michel Jaouen <[email protected]> --- drivers/mfd/db8500-prcmu.c | 42 ++++++++++++++++++++++++++++++++++++++ drivers/mfd/dbx500-prcmu-regs.h | 4 +++- include/linux/mfd/dbx500-prcmu.h | 1 + 3 files changed, 46 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c index 4f74529..e7f9539 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); @@ -517,6 +520,7 @@ static struct dsiescclk dsiescclk[3] = { } }; + /* * Used by MCDE to setup all necessary PRCMU registers */ @@ -1013,6 +1017,7 @@ 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 +1617,7 @@ 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 +1667,39 @@ 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 +1746,8 @@ 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 +2734,7 @@ 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) diff --git a/drivers/mfd/dbx500-prcmu-regs.h b/drivers/mfd/dbx500-prcmu-regs.h index 23108a6..79c76eb 100644 --- a/drivers/mfd/dbx500-prcmu-regs.h +++ b/drivers/mfd/dbx500-prcmu-regs.h @@ -61,7 +61,8 @@ #define PRCM_PLLARM_LOCKP_PRCM_PLLARM_LOCKP3 0x2 #define PRCM_ARM_CHGCLKREQ (_PRCMU_BASE + 0x114) -#define PRCM_ARM_CHGCLKREQ_PRCM_ARM_CHGCLKREQ 0x1 +#define PRCM_ARM_CHGCLKREQ_PRCM_ARM_CHGCLKREQ BIT(0) +#define PRCM_ARM_CHGCLKREQ_PRCM_ARM_DIVSEL BIT(16) #define PRCM_PLLARM_ENABLE (_PRCMU_BASE + 0x98) #define PRCM_PLLARM_ENABLE_PRCM_PLLARM_ENABLE 0x1 @@ -140,6 +141,7 @@ /* PRCMU clock/PLL/reset registers */ #define PRCM_PLLSOC0_FREQ (_PRCMU_BASE + 0x080) #define PRCM_PLLSOC1_FREQ (_PRCMU_BASE + 0x084) +#define PRCM_PLLARM_FREQ (_PRCMU_BASE + 0x088) #define PRCM_PLLDDR_FREQ (_PRCMU_BASE + 0x08C) #define PRCM_PLL_FREQ_D_SHIFT 0 #define PRCM_PLL_FREQ_D_MASK BITS(0, 7) diff --git a/include/linux/mfd/dbx500-prcmu.h b/include/linux/mfd/dbx500-prcmu.h index 5b90e94..c410d99 100644 --- a/include/linux/mfd/dbx500-prcmu.h +++ b/include/linux/mfd/dbx500-prcmu.h @@ -136,6 +136,7 @@ enum prcmu_clock { PRCMU_TIMCLK, PRCMU_PLLSOC0, PRCMU_PLLSOC1, + PRCMU_ARMSS, PRCMU_PLLDDR, PRCMU_PLLDSI, PRCMU_DSI0CLK, -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
