diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/mmio.c | 73 | ||||
| -rw-r--r-- | drivers/clocksource/sh_cmt.c | 19 | ||||
| -rw-r--r-- | drivers/clocksource/sh_tmu.c | 19 |
5 files changed, 92 insertions, 23 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 110aeeb52f9..96c92191046 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -1,2 +1,5 @@ config CLKSRC_I8253 bool + +config CLKSRC_MMIO + bool diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index cfb6383b543..b995942a506 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -7,3 +7,4 @@ obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o obj-$(CONFIG_CLKSRC_I8253) += i8253.o +obj-$(CONFIG_CLKSRC_MMIO) += mmio.o diff --git a/drivers/clocksource/mmio.c b/drivers/clocksource/mmio.c new file mode 100644 index 00000000000..c0e25125a55 --- /dev/null +++ b/drivers/clocksource/mmio.c @@ -0,0 +1,73 @@ +/* + * Generic MMIO clocksource support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/clocksource.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/slab.h> + +struct clocksource_mmio { + void __iomem *reg; + struct clocksource clksrc; +}; + +static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c) +{ + return container_of(c, struct clocksource_mmio, clksrc); +} + +cycle_t clocksource_mmio_readl_up(struct clocksource *c) +{ + return readl_relaxed(to_mmio_clksrc(c)->reg); +} + +cycle_t clocksource_mmio_readl_down(struct clocksource *c) +{ + return ~readl_relaxed(to_mmio_clksrc(c)->reg); +} + +cycle_t clocksource_mmio_readw_up(struct clocksource *c) +{ + return readw_relaxed(to_mmio_clksrc(c)->reg); +} + +cycle_t clocksource_mmio_readw_down(struct clocksource *c) +{ + return ~(unsigned)readw_relaxed(to_mmio_clksrc(c)->reg); +} + +/** + * clocksource_mmio_init - Initialize a simple mmio based clocksource + * @base: Virtual address of the clock readout register + * @name: Name of the clocksource + * @hz: Frequency of the clocksource in Hz + * @rating: Rating of the clocksource + * @bits: Number of valid bits + * @read: One of clocksource_mmio_read*() above + */ +int __init clocksource_mmio_init(void __iomem *base, const char *name, + unsigned long hz, int rating, unsigned bits, + cycle_t (*read)(struct clocksource *)) +{ + struct clocksource_mmio *cs; + + if (bits > 32 || bits < 16) + return -EINVAL; + + cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL); + if (!cs) + return -ENOMEM; + + cs->reg = base; + cs->clksrc.name = name; + cs->clksrc.rating = rating; + cs->clksrc.read = read; + cs->clksrc.mask = CLOCKSOURCE_MASK(bits); + cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS; + + return clocksource_register_hz(&cs->clksrc, hz); +} diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index f975d24890f..dc7c033ef58 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -416,11 +416,15 @@ static cycle_t sh_cmt_clocksource_read(struct clocksource *cs) static int sh_cmt_clocksource_enable(struct clocksource *cs) { + int ret; struct sh_cmt_priv *p = cs_to_sh_cmt(cs); p->total_cycles = 0; - return sh_cmt_start(p, FLAG_CLOCKSOURCE); + ret = sh_cmt_start(p, FLAG_CLOCKSOURCE); + if (!ret) + __clocksource_updatefreq_hz(cs, p->rate); + return ret; } static void sh_cmt_clocksource_disable(struct clocksource *cs) @@ -448,19 +452,10 @@ static int sh_cmt_register_clocksource(struct sh_cmt_priv *p, cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8); cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; - /* clk_get_rate() needs an enabled clock */ - clk_enable(p->clk); - p->rate = clk_get_rate(p->clk) / ((p->width == 16) ? 512 : 8); - clk_disable(p->clk); - - /* TODO: calculate good shift from rate and counter bit width */ - cs->shift = 0; - cs->mult = clocksource_hz2mult(p->rate, cs->shift); - dev_info(&p->pdev->dev, "used as clock source\n"); - clocksource_register(cs); - + /* Register with dummy 1 Hz value, gets updated in ->enable() */ + clocksource_register_hz(cs, 1); return 0; } diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c index 36aba992306..80813576861 100644 --- a/drivers/clocksource/sh_tmu.c +++ b/drivers/clocksource/sh_tmu.c @@ -199,8 +199,12 @@ static cycle_t sh_tmu_clocksource_read(struct clocksource *cs) static int sh_tmu_clocksource_enable(struct clocksource *cs) { struct sh_tmu_priv *p = cs_to_sh_tmu(cs); + int ret; - return sh_tmu_enable(p); + ret = sh_tmu_enable(p); + if (!ret) + __clocksource_updatefreq_hz(cs, p->rate); + return ret; } static void sh_tmu_clocksource_disable(struct clocksource *cs) @@ -221,17 +225,10 @@ static int sh_tmu_register_clocksource(struct sh_tmu_priv *p, cs->mask = CLOCKSOURCE_MASK(32); cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; - /* clk_get_rate() needs an enabled clock */ - clk_enable(p->clk); - /* channel will be configured at parent clock / 4 */ - p->rate = clk_get_rate(p->clk) / 4; - clk_disable(p->clk); - /* TODO: calculate good shift from rate and counter bit width */ - cs->shift = 10; - cs->mult = clocksource_hz2mult(p->rate, cs->shift); - dev_info(&p->pdev->dev, "used as clock source\n"); - clocksource_register(cs); + + /* Register with dummy 1 Hz value, gets updated in ->enable() */ + clocksource_register_hz(cs, 1); return 0; } |