diff options
author | Olof Johansson <olof@lixom.net> | 2013-02-05 12:13:10 -0800 |
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committer | Olof Johansson <olof@lixom.net> | 2013-02-05 12:13:10 -0800 |
commit | bda6f8e6cdcdb55db9b2961b6a7c9d0d97da4765 (patch) | |
tree | cec7c71c5120538352157fa1d2826efe881a7b0c /drivers/clocksource/tegra20_timer.c | |
parent | c35a0bfacb61f5c56e0e64f309d36c59c7fe8da3 (diff) | |
parent | ef3ffe5a0458606c488def757bb7f6dd013c2db5 (diff) |
Merge tag 'tegra-for-3.9-soc-ccf' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra into next/soc
From Stephen Warren:
ARM: tegra: Common Clock Framework rework
Tegra already supports the common clock framework, but had issues:
1) The clock driver was located in arch/arm/mach-tegra/ rather than
drivers/clk/.
2) A single "Tegra clock" type was implemented, rather than separate
clock types for PLL, mux, divider, ... type in HW.
3) Clock lookups by device drivers were still driven by device name
and connection ID, rather than through device tree.
This pull request solves all three issues. This required some DT changes
to add clocks properties, and driver changes to request clocks more
"correctly". Finally, this rework allows all AUXDATA to be removed from
Tegra board files, and various duplicate clock lookup entries to be
removed from the driver.
This pull request is based on the previous pull request, with tag
tegra-for-3.9-cleanup.
* tag 'tegra-for-3.9-soc-ccf' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra: (31 commits)
clk: tegra30: remove unused TEGRA_CLK_DUPLICATE()s
clk: tegra20: remove unused TEGRA_CLK_DUPLICATE()s
ARM: tegra30: remove auxdata
ARM: tegra20: remove auxdata
ASoC: tegra: remove auxdata
staging: nvec: remove use of clk_get_sys
ARM: tegra: paz00: add clock information to DT
ARM: tegra: add clock properties to Tegra30 DT
ARM: tegra: add clock properties to Tegra20 DT
spi: tegra: do not use clock name to get clock
ARM: tegra: remove legacy clock code
ARM: tegra: migrate to new clock code
clk: tegra: add clock support for Tegra30
clk: tegra: add clock support for Tegra20
clk: tegra: add Tegra specific clocks
ARM: tegra: define Tegra30 CAR binding
ARM: tegra: define Tegra20 CAR binding
ARM: tegra: move tegra_cpu_car.h to linux/clk/tegra.h
ARM: tegra: add function to read chipid
ARM: tegra: fix compile error when disable CPU_IDLE
...
Signed-off-by: Olof Johansson <olof@lixom.net>
Conflicts:
arch/arm/mach-tegra/board-dt-tegra20.c
arch/arm/mach-tegra/board-dt-tegra30.c
arch/arm/mach-tegra/common.c
arch/arm/mach-tegra/platsmp.c
drivers/clocksource/Makefile
Diffstat (limited to 'drivers/clocksource/tegra20_timer.c')
-rw-r--r-- | drivers/clocksource/tegra20_timer.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/drivers/clocksource/tegra20_timer.c b/drivers/clocksource/tegra20_timer.c new file mode 100644 index 00000000000..0bde03feb09 --- /dev/null +++ b/drivers/clocksource/tegra20_timer.c @@ -0,0 +1,281 @@ +/* + * Copyright (C) 2010 Google, Inc. + * + * Author: + * Colin Cross <ccross@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/init.h> +#include <linux/err.h> +#include <linux/time.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#include <asm/mach/time.h> +#include <asm/smp_twd.h> +#include <asm/sched_clock.h> + +#define RTC_SECONDS 0x08 +#define RTC_SHADOW_SECONDS 0x0c +#define RTC_MILLISECONDS 0x10 + +#define TIMERUS_CNTR_1US 0x10 +#define TIMERUS_USEC_CFG 0x14 +#define TIMERUS_CNTR_FREEZE 0x4c + +#define TIMER1_BASE 0x0 +#define TIMER2_BASE 0x8 +#define TIMER3_BASE 0x50 +#define TIMER4_BASE 0x58 + +#define TIMER_PTV 0x0 +#define TIMER_PCR 0x4 + +static void __iomem *timer_reg_base; +static void __iomem *rtc_base; + +static struct timespec persistent_ts; +static u64 persistent_ms, last_persistent_ms; + +#define timer_writel(value, reg) \ + __raw_writel(value, timer_reg_base + (reg)) +#define timer_readl(reg) \ + __raw_readl(timer_reg_base + (reg)) + +static int tegra_timer_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + u32 reg; + + reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0); + timer_writel(reg, TIMER3_BASE + TIMER_PTV); + + return 0; +} + +static void tegra_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + u32 reg; + + timer_writel(0, TIMER3_BASE + TIMER_PTV); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + reg = 0xC0000000 | ((1000000/HZ)-1); + timer_writel(reg, TIMER3_BASE + TIMER_PTV); + 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 tegra_clockevent = { + .name = "timer0", + .rating = 300, + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, + .set_next_event = tegra_timer_set_next_event, + .set_mode = tegra_timer_set_mode, +}; + +static u32 notrace tegra_read_sched_clock(void) +{ + return timer_readl(TIMERUS_CNTR_1US); +} + +/* + * tegra_rtc_read - Reads the Tegra RTC registers + * Care must be taken that this funciton is not called while the + * tegra_rtc driver could be executing to avoid race conditions + * on the RTC shadow register + */ +static u64 tegra_rtc_read_ms(void) +{ + u32 ms = readl(rtc_base + RTC_MILLISECONDS); + u32 s = readl(rtc_base + RTC_SHADOW_SECONDS); + return (u64)s * MSEC_PER_SEC + ms; +} + +/* + * tegra_read_persistent_clock - Return time from a persistent clock. + * + * Reads the time from a source which isn't disabled during PM, the + * 32k sync timer. Convert the cycles elapsed since last read into + * nsecs and adds to a monotonically increasing timespec. + * Care must be taken that this funciton is not called while the + * tegra_rtc driver could be executing to avoid race conditions + * on the RTC shadow register + */ +static void tegra_read_persistent_clock(struct timespec *ts) +{ + u64 delta; + struct timespec *tsp = &persistent_ts; + + last_persistent_ms = persistent_ms; + persistent_ms = tegra_rtc_read_ms(); + delta = persistent_ms - last_persistent_ms; + + timespec_add_ns(tsp, delta * NSEC_PER_MSEC); + *ts = *tsp; +} + +static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = (struct clock_event_device *)dev_id; + timer_writel(1<<30, TIMER3_BASE + TIMER_PCR); + evt->event_handler(evt); + return IRQ_HANDLED; +} + +static struct irqaction tegra_timer_irq = { + .name = "timer0", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_HIGH, + .handler = tegra_timer_interrupt, + .dev_id = &tegra_clockevent, +}; + +static const struct of_device_id timer_match[] __initconst = { + { .compatible = "nvidia,tegra20-timer" }, + {} +}; + +static const struct of_device_id rtc_match[] __initconst = { + { .compatible = "nvidia,tegra20-rtc" }, + {} +}; + +static void __init tegra20_init_timer(void) +{ + struct device_node *np; + struct clk *clk; + unsigned long rate; + int ret; + + np = of_find_matching_node(NULL, timer_match); + if (!np) { + pr_err("Failed to find timer DT node\n"); + BUG(); + } + + timer_reg_base = of_iomap(np, 0); + if (!timer_reg_base) { + pr_err("Can't map timer registers\n"); + BUG(); + } + + tegra_timer_irq.irq = irq_of_parse_and_map(np, 2); + if (tegra_timer_irq.irq <= 0) { + pr_err("Failed to map timer IRQ\n"); + BUG(); + } + + clk = clk_get_sys("timer", NULL); + if (IS_ERR(clk)) { + pr_warn("Unable to get timer clock. Assuming 12Mhz input clock.\n"); + rate = 12000000; + } else { + clk_prepare_enable(clk); + rate = clk_get_rate(clk); + } + + of_node_put(np); + + np = of_find_matching_node(NULL, rtc_match); + if (!np) { + pr_err("Failed to find RTC DT node\n"); + BUG(); + } + + rtc_base = of_iomap(np, 0); + if (!rtc_base) { + pr_err("Can't map RTC registers"); + BUG(); + } + + /* + * rtc registers are used by read_persistent_clock, keep the rtc clock + * enabled + */ + clk = clk_get_sys("rtc-tegra", NULL); + if (IS_ERR(clk)) + pr_warn("Unable to get rtc-tegra clock\n"); + else + clk_prepare_enable(clk); + + of_node_put(np); + + switch (rate) { + case 12000000: + timer_writel(0x000b, TIMERUS_USEC_CFG); + break; + case 13000000: + timer_writel(0x000c, TIMERUS_USEC_CFG); + break; + case 19200000: + timer_writel(0x045f, TIMERUS_USEC_CFG); + break; + case 26000000: + timer_writel(0x0019, TIMERUS_USEC_CFG); + break; + default: + WARN(1, "Unknown clock rate"); + } + + setup_sched_clock(tegra_read_sched_clock, 32, 1000000); + + if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US, + "timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) { + pr_err("Failed to register clocksource\n"); + BUG(); + } + + ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq); + if (ret) { + pr_err("Failed to register timer IRQ: %d\n", ret); + BUG(); + } + + tegra_clockevent.cpumask = cpu_all_mask; + tegra_clockevent.irq = tegra_timer_irq.irq; + clockevents_config_and_register(&tegra_clockevent, 1000000, + 0x1, 0x1fffffff); +#ifdef CONFIG_HAVE_ARM_TWD + twd_local_timer_of_register(); +#endif + register_persistent_clock(NULL, tegra_read_persistent_clock); +} +CLOCKSOURCE_OF_DECLARE(tegra20, "nvidia,tegra20-timer", tegra20_init_timer); + +#ifdef CONFIG_PM +static u32 usec_config; + +void tegra_timer_suspend(void) +{ + usec_config = timer_readl(TIMERUS_USEC_CFG); +} + +void tegra_timer_resume(void) +{ + timer_writel(usec_config, TIMERUS_USEC_CFG); +} +#endif |