diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/clksrc-dbx500-prcmu.c | 106 | ||||
| -rw-r--r-- | drivers/clocksource/sh_cmt.c | 35 | ||||
| -rw-r--r-- | drivers/clocksource/sh_mtu2.c | 1 | ||||
| -rw-r--r-- | drivers/clocksource/sh_tmu.c | 1 |
6 files changed, 157 insertions, 2 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 34e9c4f88926..999d6a03e436 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -15,3 +15,18 @@ config CLKSRC_MMIO config DW_APB_TIMER bool + +config CLKSRC_DBX500_PRCMU + bool "Clocksource PRCMU Timer" + depends on UX500_SOC_DB5500 || UX500_SOC_DB8500 + default y + help + Use the always on PRCMU Timer as clocksource + +config CLKSRC_DBX500_PRCMU_SCHED_CLOCK + bool "Clocksource PRCMU Timer sched_clock" + depends on (CLKSRC_DBX500_PRCMU && !NOMADIK_MTU_SCHED_CLOCK) + select HAVE_SCHED_CLOCK + default y + help + Use the always on PRCMU Timer as sched_clock diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 85ad1646a7b7..8d81a1d32653 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o obj-$(CONFIG_CLKBLD_I8253) += i8253.o obj-$(CONFIG_CLKSRC_MMIO) += mmio.o obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o +obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o
\ No newline at end of file diff --git a/drivers/clocksource/clksrc-dbx500-prcmu.c b/drivers/clocksource/clksrc-dbx500-prcmu.c new file mode 100644 index 000000000000..59feefe0e3e6 --- /dev/null +++ b/drivers/clocksource/clksrc-dbx500-prcmu.c @@ -0,0 +1,106 @@ +/* + * Copyright (C) ST-Ericsson SA 2011 + * + * License Terms: GNU General Public License v2 + * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson + * Author: Sundar Iyer for ST-Ericsson + * sched_clock implementation is based on: + * plat-nomadik/timer.c Linus Walleij <linus.walleij@stericsson.com> + * + * DBx500-PRCMU Timer + * The PRCMU has 5 timers which are available in a always-on + * power domain. We use the Timer 4 for our always-on clock + * source on DB8500 and Timer 3 on DB5500. + */ +#include <linux/clockchips.h> +#include <linux/clksrc-dbx500-prcmu.h> + +#include <asm/sched_clock.h> + +#include <mach/setup.h> +#include <mach/hardware.h> + +#define RATE_32K 32768 + +#define TIMER_MODE_CONTINOUS 0x1 +#define TIMER_DOWNCOUNT_VAL 0xffffffff + +#define PRCMU_TIMER_REF 0 +#define PRCMU_TIMER_DOWNCOUNT 0x4 +#define PRCMU_TIMER_MODE 0x8 + +#define SCHED_CLOCK_MIN_WRAP 131072 /* 2^32 / 32768 */ + +static void __iomem *clksrc_dbx500_timer_base; + +static cycle_t clksrc_dbx500_prcmu_read(struct clocksource *cs) +{ + u32 count, count2; + + do { + count = readl(clksrc_dbx500_timer_base + + PRCMU_TIMER_DOWNCOUNT); + count2 = readl(clksrc_dbx500_timer_base + + PRCMU_TIMER_DOWNCOUNT); + } while (count2 != count); + + /* Negate because the timer is a decrementing counter */ + return ~count; +} + +static struct clocksource clocksource_dbx500_prcmu = { + .name = "dbx500-prcmu-timer", + .rating = 300, + .read = clksrc_dbx500_prcmu_read, + .shift = 10, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +#ifdef CONFIG_CLKSRC_DBX500_PRCMU_SCHED_CLOCK +static DEFINE_CLOCK_DATA(cd); + +unsigned long long notrace sched_clock(void) +{ + u32 cyc; + + if (unlikely(!clksrc_dbx500_timer_base)) + return 0; + + cyc = clksrc_dbx500_prcmu_read(&clocksource_dbx500_prcmu); + + return cyc_to_sched_clock(&cd, cyc, (u32)~0); +} + +static void notrace clksrc_dbx500_prcmu_update_sched_clock(void) +{ + u32 cyc = clksrc_dbx500_prcmu_read(&clocksource_dbx500_prcmu); + update_sched_clock(&cd, cyc, (u32)~0); +} +#endif + +void __init clksrc_dbx500_prcmu_init(void __iomem *base) +{ + clksrc_dbx500_timer_base = base; + + /* + * The A9 sub system expects the timer to be configured as + * a continous looping timer. + * The PRCMU should configure it but if it for some reason + * don't we do it here. + */ + if (readl(clksrc_dbx500_timer_base + PRCMU_TIMER_MODE) != + TIMER_MODE_CONTINOUS) { + writel(TIMER_MODE_CONTINOUS, + clksrc_dbx500_timer_base + PRCMU_TIMER_MODE); + writel(TIMER_DOWNCOUNT_VAL, + clksrc_dbx500_timer_base + PRCMU_TIMER_REF); + } +#ifdef CONFIG_CLKSRC_DBX500_PRCMU_SCHED_CLOCK + init_sched_clock(&cd, clksrc_dbx500_prcmu_update_sched_clock, + 32, RATE_32K); +#endif + clocksource_calc_mult_shift(&clocksource_dbx500_prcmu, + RATE_32K, SCHED_CLOCK_MIN_WRAP); + clocksource_register(&clocksource_dbx500_prcmu); +} diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index dc7c033ef587..ca09bc421ddb 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -26,10 +26,12 @@ #include <linux/clk.h> #include <linux/irq.h> #include <linux/err.h> +#include <linux/delay.h> #include <linux/clocksource.h> #include <linux/clockchips.h> #include <linux/sh_timer.h> #include <linux/slab.h> +#include <linux/module.h> struct sh_cmt_priv { void __iomem *mapbase; @@ -150,13 +152,13 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start) static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate) { - int ret; + int k, ret; /* enable clock */ ret = clk_enable(p->clk); if (ret) { dev_err(&p->pdev->dev, "cannot enable clock\n"); - return ret; + goto err0; } /* make sure channel is disabled */ @@ -174,9 +176,38 @@ static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate) sh_cmt_write(p, CMCOR, 0xffffffff); sh_cmt_write(p, CMCNT, 0); + /* + * According to the sh73a0 user's manual, as CMCNT can be operated + * only by the RCLK (Pseudo 32 KHz), there's one restriction on + * modifying CMCNT register; two RCLK cycles are necessary before + * this register is either read or any modification of the value + * it holds is reflected in the LSI's actual operation. + * + * While at it, we're supposed to clear out the CMCNT as of this + * moment, so make sure it's processed properly here. This will + * take RCLKx2 at maximum. + */ + for (k = 0; k < 100; k++) { + if (!sh_cmt_read(p, CMCNT)) + break; + udelay(1); + } + + if (sh_cmt_read(p, CMCNT)) { + dev_err(&p->pdev->dev, "cannot clear CMCNT\n"); + ret = -ETIMEDOUT; + goto err1; + } + /* enable channel */ sh_cmt_start_stop_ch(p, 1); return 0; + err1: + /* stop clock */ + clk_disable(p->clk); + + err0: + return ret; } static void sh_cmt_disable(struct sh_cmt_priv *p) diff --git a/drivers/clocksource/sh_mtu2.c b/drivers/clocksource/sh_mtu2.c index 40630cb98237..db8d5955bad4 100644 --- a/drivers/clocksource/sh_mtu2.c +++ b/drivers/clocksource/sh_mtu2.c @@ -30,6 +30,7 @@ #include <linux/clockchips.h> #include <linux/sh_timer.h> #include <linux/slab.h> +#include <linux/module.h> struct sh_mtu2_priv { void __iomem *mapbase; diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c index 808135768617..079e96ad44e8 100644 --- a/drivers/clocksource/sh_tmu.c +++ b/drivers/clocksource/sh_tmu.c @@ -31,6 +31,7 @@ #include <linux/clockchips.h> #include <linux/sh_timer.h> #include <linux/slab.h> +#include <linux/module.h> struct sh_tmu_priv { void __iomem *mapbase; |