diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-07 18:28:42 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-07 18:28:42 (GMT) |
commit | bb9055b2744ada735a2fe555c4196ad39a83ef2a (patch) | |
tree | 014e0f462217cfa49988872a5134ae41b90b2e9c /drivers/clocksource | |
parent | 1bf25e78af317e6d5d9b5594dfeb0036e0d589d6 (diff) | |
parent | 241a9871263f3114717c0ed416a1bd1d2415d1fb (diff) | |
download | linux-bb9055b2744ada735a2fe555c4196ad39a83ef2a.tar.xz |
Merge tag 'multiplatform-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull late ARM Exynos multiplatform changes from Arnd Bergmann:
"These continue the multiplatform support for exynos, adding support
for building most of the essential drivers (clocksource, clk, irqchip)
when combined with other platforms. As a result, it should become
really easy to add full multiplatform exynos support in 3.11, although
we don't yet enable it for 3.10.
The changes were not included in the earlier multiplatform series in
order to avoid clashes with the other Exynos updates.
This also includes work from Tomasz Figa to fix the pwm clocksource
code on Exynos, which is not strictly required for multiplatform, but
related to the other patches in this set and needed as a bug fix for
at least one board."
* tag 'multiplatform-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (22 commits)
ARM: dts: exynops4210: really add universal_c210 dts
ARM: dts: exynos4210: Add basic dts file for universal_c210 board
ARM: dts: exynos4: Add node for PWM device
ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos
clocksource: samsung_pwm_timer: Work around rounding errors in clockevents core
clocksource: samsung_pwm_timer: Correct programming of clock events
clocksource: samsung_pwm_timer: Use proper clockevents max_delta
clocksource: samsung_pwm_timer: Add support for non-DT platforms
clocksource: samsung_pwm_timer: Drop unused samsung_pwm struct
clocksource: samsung_pwm_timer: Keep all driver data in a structure
clocksource: samsung_pwm_timer: Make PWM spinlock global
clocksource: samsung_pwm_timer: Let platforms select the driver
Documentation: Add device tree bindings for Samsung PWM timers
clocksource: add samsung pwm timer driver
irqchip: exynos: look up irq using irq_find_mapping
irqchip: exynos: pass irq_base from platform
irqchip: exynos: localize irq lookup for ATAGS
irqchip: exynos: allocate combiner_data dynamically
irqchip: exynos: pass max combiner number to combiner_init
ARM: exynos: add missing properties for combiner IRQs
...
Diffstat (limited to 'drivers/clocksource')
-rw-r--r-- | drivers/clocksource/Kconfig | 9 | ||||
-rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
-rw-r--r-- | drivers/clocksource/exynos_mct.c | 21 | ||||
-rw-r--r-- | drivers/clocksource/samsung_pwm_timer.c | 494 |
4 files changed, 510 insertions, 15 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index c20de4a..f151c6c 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -76,3 +76,12 @@ config CLKSRC_EXYNOS_MCT def_bool y if ARCH_EXYNOS help Support for Multi Core Timer controller on Exynos SoCs. + +config CLKSRC_SAMSUNG_PWM + bool + select CLKSRC_MMIO + help + This is a new clocksource driver for the PWM timer found in + Samsung S3C, S5P and Exynos SoCs, replacing an earlier driver + for all devicetree enabled platforms. This driver will be + needed only on systems that do not have the Exynos MCT available. diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index caacdb6..8d979c7 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_VT8500_TIMER) += vt8500_timer.o obj-$(CONFIG_ARCH_BCM) += bcm_kona_timer.o obj-$(CONFIG_CADENCE_TTC_TIMER) += cadence_ttc_timer.o obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o +obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c index 13a9e49..662fcc0 100644 --- a/drivers/clocksource/exynos_mct.c +++ b/drivers/clocksource/exynos_mct.c @@ -25,11 +25,6 @@ #include <linux/clocksource.h> #include <asm/localtimer.h> - -#include <plat/cpu.h> - -#include <mach/map.h> -#include <mach/irqs.h> #include <asm/mach/time.h> #define EXYNOS4_MCTREG(x) (x) @@ -510,18 +505,14 @@ static void __init exynos4_timer_resources(struct device_node *np, void __iomem #endif /* CONFIG_LOCAL_TIMERS */ } -void __init mct_init(void) +void __init mct_init(void __iomem *base, int irq_g0, int irq_l0, int irq_l1) { - if (soc_is_exynos4210()) { - mct_irqs[MCT_G0_IRQ] = EXYNOS4_IRQ_MCT_G0; - mct_irqs[MCT_L0_IRQ] = EXYNOS4_IRQ_MCT_L0; - mct_irqs[MCT_L1_IRQ] = EXYNOS4_IRQ_MCT_L1; - mct_int_type = MCT_INT_SPI; - } else { - panic("unable to determine mct controller type\n"); - } + mct_irqs[MCT_G0_IRQ] = irq_g0; + mct_irqs[MCT_L0_IRQ] = irq_l0; + mct_irqs[MCT_L1_IRQ] = irq_l1; + mct_int_type = MCT_INT_SPI; - exynos4_timer_resources(NULL, S5P_VA_SYSTIMER); + exynos4_timer_resources(NULL, base); exynos4_clocksource_init(); exynos4_clockevent_init(); } diff --git a/drivers/clocksource/samsung_pwm_timer.c b/drivers/clocksource/samsung_pwm_timer.c new file mode 100644 index 0000000..0234c8d --- /dev/null +++ b/drivers/clocksource/samsung_pwm_timer.c @@ -0,0 +1,494 @@ +/* + * Copyright (c) 2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * samsung - Common hr-timer support (s3c and s5p) + * + * 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/interrupt.h> +#include <linux/irq.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include <clocksource/samsung_pwm.h> + +#include <asm/sched_clock.h> + +/* + * Clocksource driver + */ + +#define REG_TCFG0 0x00 +#define REG_TCFG1 0x04 +#define REG_TCON 0x08 +#define REG_TINT_CSTAT 0x44 + +#define REG_TCNTB(chan) (0x0c + 12 * (chan)) +#define REG_TCMPB(chan) (0x10 + 12 * (chan)) + +#define TCFG0_PRESCALER_MASK 0xff +#define TCFG0_PRESCALER1_SHIFT 8 + +#define TCFG1_SHIFT(x) ((x) * 4) +#define TCFG1_MUX_MASK 0xf + +#define TCON_START(chan) (1 << (4 * (chan) + 0)) +#define TCON_MANUALUPDATE(chan) (1 << (4 * (chan) + 1)) +#define TCON_INVERT(chan) (1 << (4 * (chan) + 2)) +#define TCON_AUTORELOAD(chan) (1 << (4 * (chan) + 3)) + +DEFINE_SPINLOCK(samsung_pwm_lock); +EXPORT_SYMBOL(samsung_pwm_lock); + +struct samsung_pwm_clocksource { + void __iomem *base; + unsigned int irq[SAMSUNG_PWM_NUM]; + struct samsung_pwm_variant variant; + + struct clk *timerclk; + + unsigned int event_id; + unsigned int source_id; + unsigned int tcnt_max; + unsigned int tscaler_div; + unsigned int tdiv; + + unsigned long clock_count_per_tick; +}; + +static struct samsung_pwm_clocksource pwm; + +static void samsung_timer_set_prescale(unsigned int channel, u16 prescale) +{ + unsigned long flags; + u8 shift = 0; + u32 reg; + + if (channel >= 2) + shift = TCFG0_PRESCALER1_SHIFT; + + spin_lock_irqsave(&samsung_pwm_lock, flags); + + reg = readl(pwm.base + REG_TCFG0); + reg &= ~(TCFG0_PRESCALER_MASK << shift); + reg |= (prescale - 1) << shift; + writel(reg, pwm.base + REG_TCFG0); + + spin_unlock_irqrestore(&samsung_pwm_lock, flags); +} + +static void samsung_timer_set_divisor(unsigned int channel, u8 divisor) +{ + u8 shift = TCFG1_SHIFT(channel); + unsigned long flags; + u32 reg; + u8 bits; + + bits = (fls(divisor) - 1) - pwm.variant.div_base; + + spin_lock_irqsave(&samsung_pwm_lock, flags); + + reg = readl(pwm.base + REG_TCFG1); + reg &= ~(TCFG1_MUX_MASK << shift); + reg |= bits << shift; + writel(reg, pwm.base + REG_TCFG1); + + spin_unlock_irqrestore(&samsung_pwm_lock, flags); +} + +static void samsung_time_stop(unsigned int channel) +{ + unsigned long tcon; + unsigned long flags; + + if (channel > 0) + ++channel; + + spin_lock_irqsave(&samsung_pwm_lock, flags); + + tcon = __raw_readl(pwm.base + REG_TCON); + tcon &= ~TCON_START(channel); + __raw_writel(tcon, pwm.base + REG_TCON); + + spin_unlock_irqrestore(&samsung_pwm_lock, flags); +} + +static void samsung_time_setup(unsigned int channel, unsigned long tcnt) +{ + unsigned long tcon; + unsigned long flags; + unsigned int tcon_chan = channel; + + if (tcon_chan > 0) + ++tcon_chan; + + spin_lock_irqsave(&samsung_pwm_lock, flags); + + tcon = __raw_readl(pwm.base + REG_TCON); + + tcon &= ~(TCON_START(tcon_chan) | TCON_AUTORELOAD(tcon_chan)); + tcon |= TCON_MANUALUPDATE(tcon_chan); + + __raw_writel(tcnt, pwm.base + REG_TCNTB(channel)); + __raw_writel(tcnt, pwm.base + REG_TCMPB(channel)); + __raw_writel(tcon, pwm.base + REG_TCON); + + spin_unlock_irqrestore(&samsung_pwm_lock, flags); +} + +static void samsung_time_start(unsigned int channel, bool periodic) +{ + unsigned long tcon; + unsigned long flags; + + if (channel > 0) + ++channel; + + spin_lock_irqsave(&samsung_pwm_lock, flags); + + tcon = __raw_readl(pwm.base + REG_TCON); + + tcon &= ~TCON_MANUALUPDATE(channel); + tcon |= TCON_START(channel); + + if (periodic) + tcon |= TCON_AUTORELOAD(channel); + else + tcon &= ~TCON_AUTORELOAD(channel); + + __raw_writel(tcon, pwm.base + REG_TCON); + + spin_unlock_irqrestore(&samsung_pwm_lock, flags); +} + +static int samsung_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + /* + * This check is needed to account for internal rounding + * errors inside clockevents core, which might result in + * passing cycles = 0, which in turn would not generate any + * timer interrupt and hang the system. + * + * Another solution would be to set up the clockevent device + * with min_delta = 2, but this would unnecessarily increase + * the minimum sleep period. + */ + if (!cycles) + cycles = 1; + + samsung_time_setup(pwm.event_id, cycles); + samsung_time_start(pwm.event_id, false); + + return 0; +} + +static void samsung_timer_resume(void) +{ + /* event timer restart */ + samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1); + samsung_time_start(pwm.event_id, true); + + /* source timer restart */ + samsung_time_setup(pwm.source_id, pwm.tcnt_max); + samsung_time_start(pwm.source_id, true); +} + +static void samsung_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + samsung_time_stop(pwm.event_id); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1); + samsung_time_start(pwm.event_id, true); + break; + + case CLOCK_EVT_MODE_ONESHOT: + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + break; + + case CLOCK_EVT_MODE_RESUME: + samsung_timer_resume(); + break; + } +} + +static struct clock_event_device time_event_device = { + .name = "samsung_event_timer", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 200, + .set_next_event = samsung_set_next_event, + .set_mode = samsung_set_mode, +}; + +static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + if (pwm.variant.has_tint_cstat) { + u32 mask = (1 << pwm.event_id); + writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT); + } + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction samsung_clock_event_irq = { + .name = "samsung_time_irq", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = samsung_clock_event_isr, + .dev_id = &time_event_device, +}; + +static void __init samsung_clockevent_init(void) +{ + unsigned long pclk; + unsigned long clock_rate; + unsigned int irq_number; + + pclk = clk_get_rate(pwm.timerclk); + + samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div); + samsung_timer_set_divisor(pwm.event_id, pwm.tdiv); + + clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv); + pwm.clock_count_per_tick = clock_rate / HZ; + + time_event_device.cpumask = cpumask_of(0); + clockevents_config_and_register(&time_event_device, + clock_rate, 1, pwm.tcnt_max); + + irq_number = pwm.irq[pwm.event_id]; + setup_irq(irq_number, &samsung_clock_event_irq); + + if (pwm.variant.has_tint_cstat) { + u32 mask = (1 << pwm.event_id); + writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT); + } +} + +static void __iomem *samsung_timer_reg(void) +{ + switch (pwm.source_id) { + case 0: + case 1: + case 2: + case 3: + return pwm.base + pwm.source_id * 0x0c + 0x14; + + case 4: + return pwm.base + 0x40; + + default: + BUG(); + } +} + +/* + * Override the global weak sched_clock symbol with this + * local implementation which uses the clocksource to get some + * better resolution when scheduling the kernel. We accept that + * this wraps around for now, since it is just a relative time + * stamp. (Inspired by U300 implementation.) + */ +static u32 notrace samsung_read_sched_clock(void) +{ + void __iomem *reg = samsung_timer_reg(); + + if (!reg) + return 0; + + return ~__raw_readl(reg); +} + +static void __init samsung_clocksource_init(void) +{ + void __iomem *reg = samsung_timer_reg(); + unsigned long pclk; + unsigned long clock_rate; + int ret; + + pclk = clk_get_rate(pwm.timerclk); + + samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div); + samsung_timer_set_divisor(pwm.source_id, pwm.tdiv); + + clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv); + + samsung_time_setup(pwm.source_id, pwm.tcnt_max); + samsung_time_start(pwm.source_id, true); + + setup_sched_clock(samsung_read_sched_clock, + pwm.variant.bits, clock_rate); + + ret = clocksource_mmio_init(reg, "samsung_clocksource_timer", + clock_rate, 250, pwm.variant.bits, + clocksource_mmio_readl_down); + if (ret) + panic("samsung_clocksource_timer: can't register clocksource\n"); +} + +static void __init samsung_timer_resources(void) +{ + pwm.timerclk = clk_get(NULL, "timers"); + if (IS_ERR(pwm.timerclk)) + panic("failed to get timers clock for timer"); + + clk_prepare_enable(pwm.timerclk); + + pwm.tcnt_max = (1UL << pwm.variant.bits) - 1; + if (pwm.variant.bits == 16) { + pwm.tscaler_div = 25; + pwm.tdiv = 2; + } else { + pwm.tscaler_div = 2; + pwm.tdiv = 1; + } +} + +/* + * PWM master driver + */ +static void __init _samsung_pwm_clocksource_init(void) +{ + u8 mask; + int channel; + + mask = ~pwm.variant.output_mask & ((1 << SAMSUNG_PWM_NUM) - 1); + channel = fls(mask) - 1; + if (channel < 0) + panic("failed to find PWM channel for clocksource"); + pwm.source_id = channel; + + mask &= ~(1 << channel); + channel = fls(mask) - 1; + if (channel < 0) + panic("failed to find PWM channel for clock event"); + pwm.event_id = channel; + + samsung_timer_resources(); + samsung_clockevent_init(); + samsung_clocksource_init(); +} + +void __init samsung_pwm_clocksource_init(void __iomem *base, + unsigned int *irqs, struct samsung_pwm_variant *variant) +{ + pwm.base = base; + memcpy(&pwm.variant, variant, sizeof(pwm.variant)); + memcpy(pwm.irq, irqs, SAMSUNG_PWM_NUM * sizeof(*irqs)); + + _samsung_pwm_clocksource_init(); +} + +#ifdef CONFIG_CLKSRC_OF +static void __init samsung_pwm_alloc(struct device_node *np, + const struct samsung_pwm_variant *variant) +{ + struct resource res; + struct property *prop; + const __be32 *cur; + u32 val; + int i; + + memcpy(&pwm.variant, variant, sizeof(pwm.variant)); + for (i = 0; i < SAMSUNG_PWM_NUM; ++i) + pwm.irq[i] = irq_of_parse_and_map(np, i); + + of_property_for_each_u32(np, "samsung,pwm-outputs", prop, cur, val) { + if (val >= SAMSUNG_PWM_NUM) { + pr_warning("%s: invalid channel index in samsung,pwm-outputs property\n", + __func__); + continue; + } + pwm.variant.output_mask |= 1 << val; + } + + of_address_to_resource(np, 0, &res); + if (!request_mem_region(res.start, + resource_size(&res), "samsung-pwm")) { + pr_err("%s: failed to request IO mem region\n", __func__); + return; + } + + pwm.base = ioremap(res.start, resource_size(&res)); + if (!pwm.base) { + pr_err("%s: failed to map PWM registers\n", __func__); + release_mem_region(res.start, resource_size(&res)); + return; + } + + _samsung_pwm_clocksource_init(); +} + +static const struct samsung_pwm_variant s3c24xx_variant = { + .bits = 16, + .div_base = 1, + .has_tint_cstat = false, + .tclk_mask = (1 << 4), +}; + +static void __init s3c2410_pwm_clocksource_init(struct device_node *np) +{ + samsung_pwm_alloc(np, &s3c24xx_variant); +} +CLOCKSOURCE_OF_DECLARE(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init); + +static const struct samsung_pwm_variant s3c64xx_variant = { + .bits = 32, + .div_base = 0, + .has_tint_cstat = true, + .tclk_mask = (1 << 7) | (1 << 6) | (1 << 5), +}; + +static void __init s3c64xx_pwm_clocksource_init(struct device_node *np) +{ + samsung_pwm_alloc(np, &s3c64xx_variant); +} +CLOCKSOURCE_OF_DECLARE(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init); + +static const struct samsung_pwm_variant s5p64x0_variant = { + .bits = 32, + .div_base = 0, + .has_tint_cstat = true, + .tclk_mask = 0, +}; + +static void __init s5p64x0_pwm_clocksource_init(struct device_node *np) +{ + samsung_pwm_alloc(np, &s5p64x0_variant); +} +CLOCKSOURCE_OF_DECLARE(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init); + +static const struct samsung_pwm_variant s5p_variant = { + .bits = 32, + .div_base = 0, + .has_tint_cstat = true, + .tclk_mask = (1 << 5), +}; + +static void __init s5p_pwm_clocksource_init(struct device_node *np) +{ + samsung_pwm_alloc(np, &s5p_variant); +} +CLOCKSOURCE_OF_DECLARE(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init); +#endif |