diff options
author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-03-25 17:41:20 +0200 |
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committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-03-25 17:41:20 +0200 |
commit | 7bf7e370d5919112c223a269462cd0b546903829 (patch) | |
tree | 03ccc715239df14ae168277dbccc9d9cf4d8a2c8 /arch/arm/mach-exynos4/time.c | |
parent | 68b1a1e786f29c900fa1c516a402e24f0ece622a (diff) | |
parent | d39dd11c3e6a7af5c20bfac40594db36cf270f42 (diff) |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
[media] rc: update for bitop name changes
fs: simplify iget & friends
fs: pull inode->i_lock up out of writeback_single_inode
fs: rename inode_lock to inode_hash_lock
fs: move i_wb_list out from under inode_lock
fs: move i_sb_list out from under inode_lock
fs: remove inode_lock from iput_final and prune_icache
fs: Lock the inode LRU list separately
fs: factor inode disposal
fs: protect inode->i_state with inode->i_lock
lib, arch: add filter argument to show_mem and fix private implementations
SLUB: Write to per cpu data when allocating it
slub: Fix debugobjects with lockless fastpath
autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
autofs4 - remove autofs4_lock
autofs4 - fix d_manage() return on rcu-walk
autofs4 - fix autofs4_expire_indirect() traversal
autofs4 - fix dentry leak in autofs4_expire_direct()
autofs4 - reinstate last used update on access
vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
...
NOTE!
This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.
To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.
In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.
Diffstat (limited to 'arch/arm/mach-exynos4/time.c')
-rw-r--r-- | arch/arm/mach-exynos4/time.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos4/time.c b/arch/arm/mach-exynos4/time.c new file mode 100644 index 000000000000..86b9fa0d3639 --- /dev/null +++ b/arch/arm/mach-exynos4/time.c @@ -0,0 +1,299 @@ +/* linux/arch/arm/mach-exynos4/time.c + * + * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd. + * http://www.samsung.com + * + * EXYNOS4 (and compatible) HRT support + * PWM 2/4 is used for this feature + * + * 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/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/platform_device.h> + +#include <asm/smp_twd.h> + +#include <mach/map.h> +#include <plat/regs-timer.h> +#include <asm/mach/time.h> + +static unsigned long clock_count_per_tick; + +static struct clk *tin2; +static struct clk *tin4; +static struct clk *tdiv2; +static struct clk *tdiv4; +static struct clk *timerclk; + +static void exynos4_pwm_stop(unsigned int pwm_id) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + switch (pwm_id) { + case 2: + tcon &= ~S3C2410_TCON_T2START; + break; + case 4: + tcon &= ~S3C2410_TCON_T4START; + break; + default: + break; + } + __raw_writel(tcon, S3C2410_TCON); +} + +static void exynos4_pwm_init(unsigned int pwm_id, unsigned long tcnt) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + /* timers reload after counting zero, so reduce the count by 1 */ + tcnt--; + + /* ensure timer is stopped... */ + switch (pwm_id) { + case 2: + tcon &= ~(0xf<<12); + tcon |= S3C2410_TCON_T2MANUALUPD; + + __raw_writel(tcnt, S3C2410_TCNTB(2)); + __raw_writel(tcnt, S3C2410_TCMPB(2)); + __raw_writel(tcon, S3C2410_TCON); + + break; + case 4: + tcon &= ~(7<<20); + tcon |= S3C2410_TCON_T4MANUALUPD; + + __raw_writel(tcnt, S3C2410_TCNTB(4)); + __raw_writel(tcnt, S3C2410_TCMPB(4)); + __raw_writel(tcon, S3C2410_TCON); + + break; + default: + break; + } +} + +static inline void exynos4_pwm_start(unsigned int pwm_id, bool periodic) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + switch (pwm_id) { + case 2: + tcon |= S3C2410_TCON_T2START; + tcon &= ~S3C2410_TCON_T2MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T2RELOAD; + else + tcon &= ~S3C2410_TCON_T2RELOAD; + break; + case 4: + tcon |= S3C2410_TCON_T4START; + tcon &= ~S3C2410_TCON_T4MANUALUPD; + + if (periodic) + tcon |= S3C2410_TCON_T4RELOAD; + else + tcon &= ~S3C2410_TCON_T4RELOAD; + break; + default: + break; + } + __raw_writel(tcon, S3C2410_TCON); +} + +static int exynos4_pwm_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + exynos4_pwm_init(2, cycles); + exynos4_pwm_start(2, 0); + return 0; +} + +static void exynos4_pwm_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + exynos4_pwm_stop(2); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + exynos4_pwm_init(2, clock_count_per_tick); + exynos4_pwm_start(2, 1); + break; + case CLOCK_EVT_MODE_ONESHOT: + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_RESUME: + break; + } +} + +static struct clock_event_device pwm_event_device = { + .name = "pwm_timer2", + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .rating = 200, + .shift = 32, + .set_next_event = exynos4_pwm_set_next_event, + .set_mode = exynos4_pwm_set_mode, +}; + +irqreturn_t exynos4_clock_event_isr(int irq, void *dev_id) +{ + struct clock_event_device *evt = &pwm_event_device; + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction exynos4_clock_event_irq = { + .name = "pwm_timer2_irq", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = exynos4_clock_event_isr, +}; + +static void __init exynos4_clockevent_init(void) +{ + unsigned long pclk; + unsigned long clock_rate; + struct clk *tscaler; + + pclk = clk_get_rate(timerclk); + + /* configure clock tick */ + + tscaler = clk_get_parent(tdiv2); + + clk_set_rate(tscaler, pclk / 2); + clk_set_rate(tdiv2, pclk / 2); + clk_set_parent(tin2, tdiv2); + + clock_rate = clk_get_rate(tin2); + + clock_count_per_tick = clock_rate / HZ; + + pwm_event_device.mult = + div_sc(clock_rate, NSEC_PER_SEC, pwm_event_device.shift); + pwm_event_device.max_delta_ns = + clockevent_delta2ns(-1, &pwm_event_device); + pwm_event_device.min_delta_ns = + clockevent_delta2ns(1, &pwm_event_device); + + pwm_event_device.cpumask = cpumask_of(0); + clockevents_register_device(&pwm_event_device); + + setup_irq(IRQ_TIMER2, &exynos4_clock_event_irq); +} + +static cycle_t exynos4_pwm4_read(struct clocksource *cs) +{ + return (cycle_t) ~__raw_readl(S3C_TIMERREG(0x40)); +} + +static void exynos4_pwm4_resume(struct clocksource *cs) +{ + unsigned long pclk; + + pclk = clk_get_rate(timerclk); + + clk_set_rate(tdiv4, pclk / 2); + clk_set_parent(tin4, tdiv4); + + exynos4_pwm_init(4, ~0); + exynos4_pwm_start(4, 1); +} + +struct clocksource pwm_clocksource = { + .name = "pwm_timer4", + .rating = 250, + .read = exynos4_pwm4_read, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS , +#ifdef CONFIG_PM + .resume = exynos4_pwm4_resume, +#endif +}; + +static void __init exynos4_clocksource_init(void) +{ + unsigned long pclk; + unsigned long clock_rate; + + pclk = clk_get_rate(timerclk); + + clk_set_rate(tdiv4, pclk / 2); + clk_set_parent(tin4, tdiv4); + + clock_rate = clk_get_rate(tin4); + + exynos4_pwm_init(4, ~0); + exynos4_pwm_start(4, 1); + + if (clocksource_register_hz(&pwm_clocksource, clock_rate)) + panic("%s: can't register clocksource\n", pwm_clocksource.name); +} + +static void __init exynos4_timer_resources(void) +{ + struct platform_device tmpdev; + + tmpdev.dev.bus = &platform_bus_type; + + timerclk = clk_get(NULL, "timers"); + if (IS_ERR(timerclk)) + panic("failed to get timers clock for system timer"); + + clk_enable(timerclk); + + tmpdev.id = 2; + tin2 = clk_get(&tmpdev.dev, "pwm-tin"); + if (IS_ERR(tin2)) + panic("failed to get pwm-tin2 clock for system timer"); + + tdiv2 = clk_get(&tmpdev.dev, "pwm-tdiv"); + if (IS_ERR(tdiv2)) + panic("failed to get pwm-tdiv2 clock for system timer"); + clk_enable(tin2); + + tmpdev.id = 4; + tin4 = clk_get(&tmpdev.dev, "pwm-tin"); + if (IS_ERR(tin4)) + panic("failed to get pwm-tin4 clock for system timer"); + + tdiv4 = clk_get(&tmpdev.dev, "pwm-tdiv"); + if (IS_ERR(tdiv4)) + panic("failed to get pwm-tdiv4 clock for system timer"); + + clk_enable(tin4); +} + +static void __init exynos4_timer_init(void) +{ +#ifdef CONFIG_LOCAL_TIMERS + twd_base = S5P_VA_TWD; +#endif + + exynos4_timer_resources(); + exynos4_clockevent_init(); + exynos4_clocksource_init(); +} + +struct sys_timer exynos4_timer = { + .init = exynos4_timer_init, +}; |