diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/clocksource/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clocksource/timer-sun5i.c | 192 |
3 files changed, 197 insertions, 0 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index bdb953e15d2a..884eeff8e32d 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -37,6 +37,10 @@ config SUN4I_TIMER select CLKSRC_MMIO bool +config SUN5I_HSTIMER + select CLKSRC_MMIO + bool + config VT8500_TIMER bool diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 33621efb9148..358358d87b6d 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -22,6 +22,7 @@ obj-$(CONFIG_ARCH_MOXART) += moxart_timer.o obj-$(CONFIG_ARCH_MXS) += mxs_timer.o obj-$(CONFIG_ARCH_PRIMA2) += timer-prima2.o obj-$(CONFIG_SUN4I_TIMER) += sun4i_timer.o +obj-$(CONFIG_SUN5I_HSTIMER) += timer-sun5i.o obj-$(CONFIG_ARCH_TEGRA) += tegra20_timer.o obj-$(CONFIG_VT8500_TIMER) += vt8500_timer.o obj-$(CONFIG_ARCH_NSPIRE) += zevio-timer.o diff --git a/drivers/clocksource/timer-sun5i.c b/drivers/clocksource/timer-sun5i.c new file mode 100644 index 000000000000..bddc52233d2a --- /dev/null +++ b/drivers/clocksource/timer-sun5i.c @@ -0,0 +1,192 @@ +/* + * Allwinner SoCs hstimer driver. + * + * Copyright (C) 2013 Maxime Ripard + * + * Maxime Ripard <maxime.ripard@free-electrons.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqreturn.h> +#include <linux/sched_clock.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#define TIMER_IRQ_EN_REG 0x00 +#define TIMER_IRQ_EN(val) BIT(val) +#define TIMER_IRQ_ST_REG 0x04 +#define TIMER_CTL_REG(val) (0x20 * (val) + 0x10) +#define TIMER_CTL_ENABLE BIT(0) +#define TIMER_CTL_RELOAD BIT(1) +#define TIMER_CTL_CLK_PRES(val) (((val) & 0x7) << 4) +#define TIMER_CTL_ONESHOT BIT(7) +#define TIMER_INTVAL_LO_REG(val) (0x20 * (val) + 0x14) +#define TIMER_INTVAL_HI_REG(val) (0x20 * (val) + 0x18) +#define TIMER_CNTVAL_LO_REG(val) (0x20 * (val) + 0x1c) +#define TIMER_CNTVAL_HI_REG(val) (0x20 * (val) + 0x20) + +#define TIMER_SYNC_TICKS 3 + +static void __iomem *timer_base; +static u32 ticks_per_jiffy; + +/* + * When we disable a timer, we need to wait at least for 2 cycles of + * the timer source clock. We will use for that the clocksource timer + * that is already setup and runs at the same frequency than the other + * timers, and we never will be disabled. + */ +static void sun5i_clkevt_sync(void) +{ + u32 old = readl(timer_base + TIMER_CNTVAL_LO_REG(1)); + + while ((old - readl(timer_base + TIMER_CNTVAL_LO_REG(1))) < TIMER_SYNC_TICKS) + cpu_relax(); +} + +static void sun5i_clkevt_time_stop(u8 timer) +{ + u32 val = readl(timer_base + TIMER_CTL_REG(timer)); + writel(val & ~TIMER_CTL_ENABLE, timer_base + TIMER_CTL_REG(timer)); + + sun5i_clkevt_sync(); +} + +static void sun5i_clkevt_time_setup(u8 timer, u32 delay) +{ + writel(delay, timer_base + TIMER_INTVAL_LO_REG(timer)); +} + +static void sun5i_clkevt_time_start(u8 timer, bool periodic) +{ + u32 val = readl(timer_base + TIMER_CTL_REG(timer)); + + if (periodic) + val &= ~TIMER_CTL_ONESHOT; + else + val |= TIMER_CTL_ONESHOT; + + writel(val | TIMER_CTL_ENABLE | TIMER_CTL_RELOAD, + timer_base + TIMER_CTL_REG(timer)); +} + +static void sun5i_clkevt_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + sun5i_clkevt_time_stop(0); + sun5i_clkevt_time_setup(0, ticks_per_jiffy); + sun5i_clkevt_time_start(0, true); + break; + case CLOCK_EVT_MODE_ONESHOT: + sun5i_clkevt_time_stop(0); + sun5i_clkevt_time_start(0, false); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + sun5i_clkevt_time_stop(0); + break; + } +} + +static int sun5i_clkevt_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + sun5i_clkevt_time_stop(0); + sun5i_clkevt_time_setup(0, evt - TIMER_SYNC_TICKS); + sun5i_clkevt_time_start(0, false); + + return 0; +} + +static struct clock_event_device sun5i_clockevent = { + .name = "sun5i_tick", + .rating = 340, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = sun5i_clkevt_mode, + .set_next_event = sun5i_clkevt_next_event, +}; + + +static irqreturn_t sun5i_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = (struct clock_event_device *)dev_id; + + writel(0x1, timer_base + TIMER_IRQ_ST_REG); + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static struct irqaction sun5i_timer_irq = { + .name = "sun5i_timer0", + .flags = IRQF_TIMER | IRQF_IRQPOLL, + .handler = sun5i_timer_interrupt, + .dev_id = &sun5i_clockevent, +}; + +static u32 sun5i_timer_sched_read(void) +{ + return ~readl(timer_base + TIMER_CNTVAL_LO_REG(1)); +} + +static void __init sun5i_timer_init(struct device_node *node) +{ + unsigned long rate; + struct clk *clk; + int ret, irq; + u32 val; + + timer_base = of_iomap(node, 0); + if (!timer_base) + panic("Can't map registers"); + + irq = irq_of_parse_and_map(node, 0); + if (irq <= 0) + panic("Can't parse IRQ"); + + clk = of_clk_get(node, 0); + if (IS_ERR(clk)) + panic("Can't get timer clock"); + clk_prepare_enable(clk); + rate = clk_get_rate(clk); + + writel(~0, timer_base + TIMER_INTVAL_LO_REG(1)); + writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD, + timer_base + TIMER_CTL_REG(1)); + + setup_sched_clock(sun5i_timer_sched_read, 32, rate); + clocksource_mmio_init(timer_base + TIMER_CNTVAL_LO_REG(1), node->name, + rate, 340, 32, clocksource_mmio_readl_down); + + ticks_per_jiffy = DIV_ROUND_UP(rate, HZ); + + ret = setup_irq(irq, &sun5i_timer_irq); + if (ret) + pr_warn("failed to setup irq %d\n", irq); + + /* Enable timer0 interrupt */ + val = readl(timer_base + TIMER_IRQ_EN_REG); + writel(val | TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_EN_REG); + + sun5i_clockevent.cpumask = cpu_possible_mask; + sun5i_clockevent.irq = irq; + + clockevents_config_and_register(&sun5i_clockevent, rate, + TIMER_SYNC_TICKS, 0xffffffff); +} +CLOCKSOURCE_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer", + sun5i_timer_init); +CLOCKSOURCE_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer", + sun5i_timer_init); |