diff options
Diffstat (limited to 'drivers/clocksource/sh_cmt.c')
| -rw-r--r-- | drivers/clocksource/sh_cmt.c | 116 |
1 files changed, 97 insertions, 19 deletions
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index 1c92c39..cf56a2a 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -18,7 +18,6 @@ */ #include <linux/init.h> -#include <linux/bootmem.h> #include <linux/platform_device.h> #include <linux/spinlock.h> #include <linux/interrupt.h> @@ -29,7 +28,7 @@ #include <linux/err.h> #include <linux/clocksource.h> #include <linux/clockchips.h> -#include <linux/sh_cmt.h> +#include <linux/sh_timer.h> struct sh_cmt_priv { void __iomem *mapbase; @@ -47,6 +46,7 @@ struct sh_cmt_priv { unsigned long rate; spinlock_t lock; struct clock_event_device ced; + struct clocksource cs; unsigned long total_cycles; }; @@ -59,7 +59,7 @@ static DEFINE_SPINLOCK(sh_cmt_lock); static inline unsigned long sh_cmt_read(struct sh_cmt_priv *p, int reg_nr) { - struct sh_cmt_config *cfg = p->pdev->dev.platform_data; + struct sh_timer_config *cfg = p->pdev->dev.platform_data; void __iomem *base = p->mapbase; unsigned long offs; @@ -83,7 +83,7 @@ static inline unsigned long sh_cmt_read(struct sh_cmt_priv *p, int reg_nr) static inline void sh_cmt_write(struct sh_cmt_priv *p, int reg_nr, unsigned long value) { - struct sh_cmt_config *cfg = p->pdev->dev.platform_data; + struct sh_timer_config *cfg = p->pdev->dev.platform_data; void __iomem *base = p->mapbase; unsigned long offs; @@ -110,23 +110,28 @@ static unsigned long sh_cmt_get_counter(struct sh_cmt_priv *p, int *has_wrapped) { unsigned long v1, v2, v3; + int o1, o2; + + o1 = sh_cmt_read(p, CMCSR) & p->overflow_bit; /* Make sure the timer value is stable. Stolen from acpi_pm.c */ do { + o2 = o1; v1 = sh_cmt_read(p, CMCNT); v2 = sh_cmt_read(p, CMCNT); v3 = sh_cmt_read(p, CMCNT); - } while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1) - || (v3 > v1 && v3 < v2))); + o1 = sh_cmt_read(p, CMCSR) & p->overflow_bit; + } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3) + || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); - *has_wrapped = sh_cmt_read(p, CMCSR) & p->overflow_bit; + *has_wrapped = o1; return v2; } static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start) { - struct sh_cmt_config *cfg = p->pdev->dev.platform_data; + struct sh_timer_config *cfg = p->pdev->dev.platform_data; unsigned long flags, value; /* start stop register shared by multiple timer channels */ @@ -144,7 +149,7 @@ 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) { - struct sh_cmt_config *cfg = p->pdev->dev.platform_data; + struct sh_timer_config *cfg = p->pdev->dev.platform_data; int ret; /* enable clock */ @@ -153,16 +158,18 @@ static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate) pr_err("sh_cmt: cannot enable clock \"%s\"\n", cfg->clk); return ret; } - *rate = clk_get_rate(p->clk) / 8; /* make sure channel is disabled */ sh_cmt_start_stop_ch(p, 0); /* configure channel, periodic mode and maximum timeout */ - if (p->width == 16) - sh_cmt_write(p, CMCSR, 0); - else + if (p->width == 16) { + *rate = clk_get_rate(p->clk) / 512; + sh_cmt_write(p, CMCSR, 0x43); + } else { + *rate = clk_get_rate(p->clk) / 8; sh_cmt_write(p, CMCSR, 0x01a4); + } sh_cmt_write(p, CMCOR, 0xffffffff); sh_cmt_write(p, CMCNT, 0); @@ -376,6 +383,68 @@ static void sh_cmt_stop(struct sh_cmt_priv *p, unsigned long flag) spin_unlock_irqrestore(&p->lock, flags); } +static struct sh_cmt_priv *cs_to_sh_cmt(struct clocksource *cs) +{ + return container_of(cs, struct sh_cmt_priv, cs); +} + +static cycle_t sh_cmt_clocksource_read(struct clocksource *cs) +{ + struct sh_cmt_priv *p = cs_to_sh_cmt(cs); + unsigned long flags, raw; + unsigned long value; + int has_wrapped; + + spin_lock_irqsave(&p->lock, flags); + value = p->total_cycles; + raw = sh_cmt_get_counter(p, &has_wrapped); + + if (unlikely(has_wrapped)) + raw += p->match_value; + spin_unlock_irqrestore(&p->lock, flags); + + return value + raw; +} + +static int sh_cmt_clocksource_enable(struct clocksource *cs) +{ + struct sh_cmt_priv *p = cs_to_sh_cmt(cs); + int ret; + + p->total_cycles = 0; + + ret = sh_cmt_start(p, FLAG_CLOCKSOURCE); + if (ret) + return ret; + + /* TODO: calculate good shift from rate and counter bit width */ + cs->shift = 0; + cs->mult = clocksource_hz2mult(p->rate, cs->shift); + return 0; +} + +static void sh_cmt_clocksource_disable(struct clocksource *cs) +{ + sh_cmt_stop(cs_to_sh_cmt(cs), FLAG_CLOCKSOURCE); +} + +static int sh_cmt_register_clocksource(struct sh_cmt_priv *p, + char *name, unsigned long rating) +{ + struct clocksource *cs = &p->cs; + + cs->name = name; + cs->rating = rating; + cs->read = sh_cmt_clocksource_read; + cs->enable = sh_cmt_clocksource_enable; + cs->disable = sh_cmt_clocksource_disable; + cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8); + cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; + pr_info("sh_cmt: %s used as clock source\n", cs->name); + clocksource_register(cs); + return 0; +} + static struct sh_cmt_priv *ced_to_sh_cmt(struct clock_event_device *ced) { return container_of(ced, struct sh_cmt_priv, ced); @@ -468,9 +537,9 @@ static void sh_cmt_register_clockevent(struct sh_cmt_priv *p, clockevents_register_device(ced); } -int sh_cmt_register(struct sh_cmt_priv *p, char *name, - unsigned long clockevent_rating, - unsigned long clocksource_rating) +static int sh_cmt_register(struct sh_cmt_priv *p, char *name, + unsigned long clockevent_rating, + unsigned long clocksource_rating) { if (p->width == (sizeof(p->max_match_value) * 8)) p->max_match_value = ~0; @@ -483,12 +552,15 @@ int sh_cmt_register(struct sh_cmt_priv *p, char *name, if (clockevent_rating) sh_cmt_register_clockevent(p, name, clockevent_rating); + if (clocksource_rating) + sh_cmt_register_clocksource(p, name, clocksource_rating); + return 0; } static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev) { - struct sh_cmt_config *cfg = pdev->dev.platform_data; + struct sh_timer_config *cfg = pdev->dev.platform_data; struct resource *res; int irq, ret; ret = -ENXIO; @@ -545,7 +617,7 @@ static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev) if (resource_size(res) == 6) { p->width = 16; p->overflow_bit = 0x80; - p->clear_bits = ~0xc0; + p->clear_bits = ~0x80; } else { p->width = 32; p->overflow_bit = 0x8000; @@ -566,8 +638,14 @@ static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev) static int __devinit sh_cmt_probe(struct platform_device *pdev) { struct sh_cmt_priv *p = platform_get_drvdata(pdev); + struct sh_timer_config *cfg = pdev->dev.platform_data; int ret; + if (p) { + pr_info("sh_cmt: %s kept as earlytimer\n", cfg->name); + return 0; + } + p = kmalloc(sizeof(*p), GFP_KERNEL); if (p == NULL) { dev_err(&pdev->dev, "failed to allocate driver data\n"); @@ -577,7 +655,6 @@ static int __devinit sh_cmt_probe(struct platform_device *pdev) ret = sh_cmt_setup(p, pdev); if (ret) { kfree(p); - platform_set_drvdata(pdev, NULL); } return ret; @@ -606,6 +683,7 @@ static void __exit sh_cmt_exit(void) platform_driver_unregister(&sh_cmt_device_driver); } +early_platform_init("earlytimer", &sh_cmt_device_driver); module_init(sh_cmt_init); module_exit(sh_cmt_exit); |