diff options
Diffstat (limited to 'drivers/clocksource/rockchip_timer.c')
| -rw-r--r-- | drivers/clocksource/rockchip_timer.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/clocksource/rockchip_timer.c b/drivers/clocksource/rockchip_timer.c new file mode 100644 index 000000000..a35993baf --- /dev/null +++ b/drivers/clocksource/rockchip_timer.c @@ -0,0 +1,180 @@ +/* + * Rockchip timer support + * + * Copyright (C) Daniel Lezcano <daniel.lezcano@linaro.org> + * + * 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/clk.h> +#include <linux/clockchips.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#define TIMER_NAME "rk_timer" + +#define TIMER_LOAD_COUNT0 0x00 +#define TIMER_LOAD_COUNT1 0x04 +#define TIMER_CONTROL_REG 0x10 +#define TIMER_INT_STATUS 0x18 + +#define TIMER_DISABLE 0x0 +#define TIMER_ENABLE 0x1 +#define TIMER_MODE_FREE_RUNNING (0 << 1) +#define TIMER_MODE_USER_DEFINED_COUNT (1 << 1) +#define TIMER_INT_UNMASK (1 << 2) + +struct bc_timer { + struct clock_event_device ce; + void __iomem *base; + u32 freq; +}; + +static struct bc_timer bc_timer; + +static inline struct bc_timer *rk_timer(struct clock_event_device *ce) +{ + return container_of(ce, struct bc_timer, ce); +} + +static inline void __iomem *rk_base(struct clock_event_device *ce) +{ + return rk_timer(ce)->base; +} + +static inline void rk_timer_disable(struct clock_event_device *ce) +{ + writel_relaxed(TIMER_DISABLE, rk_base(ce) + TIMER_CONTROL_REG); + dsb(); +} + +static inline void rk_timer_enable(struct clock_event_device *ce, u32 flags) +{ + writel_relaxed(TIMER_ENABLE | TIMER_INT_UNMASK | flags, + rk_base(ce) + TIMER_CONTROL_REG); + dsb(); +} + +static void rk_timer_update_counter(unsigned long cycles, + struct clock_event_device *ce) +{ + writel_relaxed(cycles, rk_base(ce) + TIMER_LOAD_COUNT0); + writel_relaxed(0, rk_base(ce) + TIMER_LOAD_COUNT1); + dsb(); +} + +static void rk_timer_interrupt_clear(struct clock_event_device *ce) +{ + writel_relaxed(1, rk_base(ce) + TIMER_INT_STATUS); + dsb(); +} + +static inline int rk_timer_set_next_event(unsigned long cycles, + struct clock_event_device *ce) +{ + rk_timer_disable(ce); + rk_timer_update_counter(cycles, ce); + rk_timer_enable(ce, TIMER_MODE_USER_DEFINED_COUNT); + return 0; +} + +static inline void rk_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *ce) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + rk_timer_disable(ce); + rk_timer_update_counter(rk_timer(ce)->freq / HZ - 1, ce); + rk_timer_enable(ce, TIMER_MODE_FREE_RUNNING); + break; + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_RESUME: + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + rk_timer_disable(ce); + break; + } +} + +static irqreturn_t rk_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *ce = dev_id; + + rk_timer_interrupt_clear(ce); + + if (ce->mode == CLOCK_EVT_MODE_ONESHOT) + rk_timer_disable(ce); + + ce->event_handler(ce); + + return IRQ_HANDLED; +} + +static void __init rk_timer_init(struct device_node *np) +{ + struct clock_event_device *ce = &bc_timer.ce; + struct clk *timer_clk; + struct clk *pclk; + int ret, irq; + + bc_timer.base = of_iomap(np, 0); + if (!bc_timer.base) { + pr_err("Failed to get base address for '%s'\n", TIMER_NAME); + return; + } + + pclk = of_clk_get_by_name(np, "pclk"); + if (IS_ERR(pclk)) { + pr_err("Failed to get pclk for '%s'\n", TIMER_NAME); + return; + } + + if (clk_prepare_enable(pclk)) { + pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME); + return; + } + + timer_clk = of_clk_get_by_name(np, "timer"); + if (IS_ERR(timer_clk)) { + pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME); + return; + } + + if (clk_prepare_enable(timer_clk)) { + pr_err("Failed to enable timer clock\n"); + return; + } + + bc_timer.freq = clk_get_rate(timer_clk); + + irq = irq_of_parse_and_map(np, 0); + if (irq == NO_IRQ) { + pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME); + return; + } + + ce->name = TIMER_NAME; + ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + ce->set_next_event = rk_timer_set_next_event; + ce->set_mode = rk_timer_set_mode; + ce->irq = irq; + ce->cpumask = cpumask_of(0); + ce->rating = 250; + + rk_timer_interrupt_clear(ce); + rk_timer_disable(ce); + + ret = request_irq(irq, rk_timer_interrupt, IRQF_TIMER, TIMER_NAME, ce); + if (ret) { + pr_err("Failed to initialize '%s': %d\n", TIMER_NAME, ret); + return; + } + + clockevents_config_and_register(ce, bc_timer.freq, 1, UINT_MAX); +} +CLOCKSOURCE_OF_DECLARE(rk_timer, "rockchip,rk3288-timer", rk_timer_init); |