diff options
author | Baolin Wang <baolin.wang@spreadtrum.com> | 2018-01-08 14:28:47 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-01-08 17:57:24 +0100 |
commit | 067bc9144766495650e621b79bd2bc199cee0769 (patch) | |
tree | 9cf0476a58feeb5ae9be064c916f4ef412f57341 /drivers/clocksource/timer-sprd.c | |
parent | 286f30db8b713b17e048bb86df1e257fd8695498 (diff) | |
download | linux-067bc9144766495650e621b79bd2bc199cee0769.tar.bz2 |
clocksource/drivers/spreadtrum: Add timer driver for the Spreadtrum SC9860 platform
The Spreadtrum SC9860 platform will use the architected timers as local
clock events, but we also need a broadcast timer device to wake up the
CPUs when the CPUs are in sleep mode.
The Spreadtrum timer can support 32-bit or 64-bit counters, as well as
supporting period mode or one-shot mode.
Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1515418139-23276-8-git-send-email-daniel.lezcano@linaro.org
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/clocksource/timer-sprd.c')
-rw-r--r-- | drivers/clocksource/timer-sprd.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-sprd.c b/drivers/clocksource/timer-sprd.c new file mode 100644 index 000000000000..ef9ebeafb3ed --- /dev/null +++ b/drivers/clocksource/timer-sprd.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2017 Spreadtrum Communications Inc. + */ + +#include <linux/init.h> +#include <linux/interrupt.h> + +#include "timer-of.h" + +#define TIMER_NAME "sprd_timer" + +#define TIMER_LOAD_LO 0x0 +#define TIMER_LOAD_HI 0x4 +#define TIMER_VALUE_LO 0x8 +#define TIMER_VALUE_HI 0xc + +#define TIMER_CTL 0x10 +#define TIMER_CTL_PERIOD_MODE BIT(0) +#define TIMER_CTL_ENABLE BIT(1) +#define TIMER_CTL_64BIT_WIDTH BIT(16) + +#define TIMER_INT 0x14 +#define TIMER_INT_EN BIT(0) +#define TIMER_INT_RAW_STS BIT(1) +#define TIMER_INT_MASK_STS BIT(2) +#define TIMER_INT_CLR BIT(3) + +#define TIMER_VALUE_SHDW_LO 0x18 +#define TIMER_VALUE_SHDW_HI 0x1c + +#define TIMER_VALUE_LO_MASK GENMASK(31, 0) + +static void sprd_timer_enable(void __iomem *base, u32 flag) +{ + u32 val = readl_relaxed(base + TIMER_CTL); + + val |= TIMER_CTL_ENABLE; + if (flag & TIMER_CTL_64BIT_WIDTH) + val |= TIMER_CTL_64BIT_WIDTH; + else + val &= ~TIMER_CTL_64BIT_WIDTH; + + if (flag & TIMER_CTL_PERIOD_MODE) + val |= TIMER_CTL_PERIOD_MODE; + else + val &= ~TIMER_CTL_PERIOD_MODE; + + writel_relaxed(val, base + TIMER_CTL); +} + +static void sprd_timer_disable(void __iomem *base) +{ + u32 val = readl_relaxed(base + TIMER_CTL); + + val &= ~TIMER_CTL_ENABLE; + writel_relaxed(val, base + TIMER_CTL); +} + +static void sprd_timer_update_counter(void __iomem *base, unsigned long cycles) +{ + writel_relaxed(cycles & TIMER_VALUE_LO_MASK, base + TIMER_LOAD_LO); + writel_relaxed(0, base + TIMER_LOAD_HI); +} + +static void sprd_timer_enable_interrupt(void __iomem *base) +{ + writel_relaxed(TIMER_INT_EN, base + TIMER_INT); +} + +static void sprd_timer_clear_interrupt(void __iomem *base) +{ + u32 val = readl_relaxed(base + TIMER_INT); + + val |= TIMER_INT_CLR; + writel_relaxed(val, base + TIMER_INT); +} + +static int sprd_timer_set_next_event(unsigned long cycles, + struct clock_event_device *ce) +{ + struct timer_of *to = to_timer_of(ce); + + sprd_timer_disable(timer_of_base(to)); + sprd_timer_update_counter(timer_of_base(to), cycles); + sprd_timer_enable(timer_of_base(to), 0); + + return 0; +} + +static int sprd_timer_set_periodic(struct clock_event_device *ce) +{ + struct timer_of *to = to_timer_of(ce); + + sprd_timer_disable(timer_of_base(to)); + sprd_timer_update_counter(timer_of_base(to), timer_of_period(to)); + sprd_timer_enable(timer_of_base(to), TIMER_CTL_PERIOD_MODE); + + return 0; +} + +static int sprd_timer_shutdown(struct clock_event_device *ce) +{ + struct timer_of *to = to_timer_of(ce); + + sprd_timer_disable(timer_of_base(to)); + return 0; +} + +static irqreturn_t sprd_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *ce = (struct clock_event_device *)dev_id; + struct timer_of *to = to_timer_of(ce); + + sprd_timer_clear_interrupt(timer_of_base(to)); + + if (clockevent_state_oneshot(ce)) + sprd_timer_disable(timer_of_base(to)); + + ce->event_handler(ce); + return IRQ_HANDLED; +} + +static struct timer_of to = { + .flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK, + + .clkevt = { + .name = TIMER_NAME, + .rating = 300, + .features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT, + .set_state_shutdown = sprd_timer_shutdown, + .set_state_periodic = sprd_timer_set_periodic, + .set_next_event = sprd_timer_set_next_event, + .cpumask = cpu_possible_mask, + }, + + .of_irq = { + .handler = sprd_timer_interrupt, + .flags = IRQF_TIMER | IRQF_IRQPOLL, + }, +}; + +static int __init sprd_timer_init(struct device_node *np) +{ + int ret; + + ret = timer_of_init(np, &to); + if (ret) + return ret; + + sprd_timer_enable_interrupt(timer_of_base(&to)); + clockevents_config_and_register(&to.clkevt, timer_of_rate(&to), + 1, UINT_MAX); + + return 0; +} + +TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init); |