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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clocksource/timer-sun5i.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | drivers/clocksource/timer-sun5i.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-sun5i.c b/drivers/clocksource/timer-sun5i.c new file mode 100644 index 000000000..7d5fa9069 --- /dev/null +++ b/drivers/clocksource/timer-sun5i.c @@ -0,0 +1,372 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Allwinner SoCs hstimer driver. + * + * Copyright (C) 2013 Maxime Ripard + * + * Maxime Ripard <maxime.ripard@free-electrons.com> + */ + +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqreturn.h> +#include <linux/reset.h> +#include <linux/slab.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 + +struct sun5i_timer { + void __iomem *base; + struct clk *clk; + struct notifier_block clk_rate_cb; + u32 ticks_per_jiffy; +}; + +#define to_sun5i_timer(x) \ + container_of(x, struct sun5i_timer, clk_rate_cb) + +struct sun5i_timer_clksrc { + struct sun5i_timer timer; + struct clocksource clksrc; +}; + +#define to_sun5i_timer_clksrc(x) \ + container_of(x, struct sun5i_timer_clksrc, clksrc) + +struct sun5i_timer_clkevt { + struct sun5i_timer timer; + struct clock_event_device clkevt; +}; + +#define to_sun5i_timer_clkevt(x) \ + container_of(x, struct sun5i_timer_clkevt, clkevt) + +/* + * 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(struct sun5i_timer_clkevt *ce) +{ + u32 old = readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1)); + + while ((old - readl(ce->timer.base + TIMER_CNTVAL_LO_REG(1))) < TIMER_SYNC_TICKS) + cpu_relax(); +} + +static void sun5i_clkevt_time_stop(struct sun5i_timer_clkevt *ce, u8 timer) +{ + u32 val = readl(ce->timer.base + TIMER_CTL_REG(timer)); + writel(val & ~TIMER_CTL_ENABLE, ce->timer.base + TIMER_CTL_REG(timer)); + + sun5i_clkevt_sync(ce); +} + +static void sun5i_clkevt_time_setup(struct sun5i_timer_clkevt *ce, u8 timer, u32 delay) +{ + writel(delay, ce->timer.base + TIMER_INTVAL_LO_REG(timer)); +} + +static void sun5i_clkevt_time_start(struct sun5i_timer_clkevt *ce, u8 timer, bool periodic) +{ + u32 val = readl(ce->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, + ce->timer.base + TIMER_CTL_REG(timer)); +} + +static int sun5i_clkevt_shutdown(struct clock_event_device *clkevt) +{ + struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); + + sun5i_clkevt_time_stop(ce, 0); + return 0; +} + +static int sun5i_clkevt_set_oneshot(struct clock_event_device *clkevt) +{ + struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); + + sun5i_clkevt_time_stop(ce, 0); + sun5i_clkevt_time_start(ce, 0, false); + return 0; +} + +static int sun5i_clkevt_set_periodic(struct clock_event_device *clkevt) +{ + struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); + + sun5i_clkevt_time_stop(ce, 0); + sun5i_clkevt_time_setup(ce, 0, ce->timer.ticks_per_jiffy); + sun5i_clkevt_time_start(ce, 0, true); + return 0; +} + +static int sun5i_clkevt_next_event(unsigned long evt, + struct clock_event_device *clkevt) +{ + struct sun5i_timer_clkevt *ce = to_sun5i_timer_clkevt(clkevt); + + sun5i_clkevt_time_stop(ce, 0); + sun5i_clkevt_time_setup(ce, 0, evt - TIMER_SYNC_TICKS); + sun5i_clkevt_time_start(ce, 0, false); + + return 0; +} + +static irqreturn_t sun5i_timer_interrupt(int irq, void *dev_id) +{ + struct sun5i_timer_clkevt *ce = dev_id; + + writel(0x1, ce->timer.base + TIMER_IRQ_ST_REG); + ce->clkevt.event_handler(&ce->clkevt); + + return IRQ_HANDLED; +} + +static u64 sun5i_clksrc_read(struct clocksource *clksrc) +{ + struct sun5i_timer_clksrc *cs = to_sun5i_timer_clksrc(clksrc); + + return ~readl(cs->timer.base + TIMER_CNTVAL_LO_REG(1)); +} + +static int sun5i_rate_cb_clksrc(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct clk_notifier_data *ndata = data; + struct sun5i_timer *timer = to_sun5i_timer(nb); + struct sun5i_timer_clksrc *cs = container_of(timer, struct sun5i_timer_clksrc, timer); + + switch (event) { + case PRE_RATE_CHANGE: + clocksource_unregister(&cs->clksrc); + break; + + case POST_RATE_CHANGE: + clocksource_register_hz(&cs->clksrc, ndata->new_rate); + break; + + default: + break; + } + + return NOTIFY_DONE; +} + +static int __init sun5i_setup_clocksource(struct device_node *node, + void __iomem *base, + struct clk *clk, int irq) +{ + struct sun5i_timer_clksrc *cs; + unsigned long rate; + int ret; + + cs = kzalloc(sizeof(*cs), GFP_KERNEL); + if (!cs) + return -ENOMEM; + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("Couldn't enable parent clock\n"); + goto err_free; + } + + rate = clk_get_rate(clk); + if (!rate) { + pr_err("Couldn't get parent clock rate\n"); + ret = -EINVAL; + goto err_disable_clk; + } + + cs->timer.base = base; + cs->timer.clk = clk; + cs->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clksrc; + cs->timer.clk_rate_cb.next = NULL; + + ret = clk_notifier_register(clk, &cs->timer.clk_rate_cb); + if (ret) { + pr_err("Unable to register clock notifier.\n"); + goto err_disable_clk; + } + + writel(~0, base + TIMER_INTVAL_LO_REG(1)); + writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD, + base + TIMER_CTL_REG(1)); + + cs->clksrc.name = node->name; + cs->clksrc.rating = 340; + cs->clksrc.read = sun5i_clksrc_read; + cs->clksrc.mask = CLOCKSOURCE_MASK(32); + cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS; + + ret = clocksource_register_hz(&cs->clksrc, rate); + if (ret) { + pr_err("Couldn't register clock source.\n"); + goto err_remove_notifier; + } + + return 0; + +err_remove_notifier: + clk_notifier_unregister(clk, &cs->timer.clk_rate_cb); +err_disable_clk: + clk_disable_unprepare(clk); +err_free: + kfree(cs); + return ret; +} + +static int sun5i_rate_cb_clkevt(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct clk_notifier_data *ndata = data; + struct sun5i_timer *timer = to_sun5i_timer(nb); + struct sun5i_timer_clkevt *ce = container_of(timer, struct sun5i_timer_clkevt, timer); + + if (event == POST_RATE_CHANGE) { + clockevents_update_freq(&ce->clkevt, ndata->new_rate); + ce->timer.ticks_per_jiffy = DIV_ROUND_UP(ndata->new_rate, HZ); + } + + return NOTIFY_DONE; +} + +static int __init sun5i_setup_clockevent(struct device_node *node, void __iomem *base, + struct clk *clk, int irq) +{ + struct sun5i_timer_clkevt *ce; + unsigned long rate; + int ret; + u32 val; + + ce = kzalloc(sizeof(*ce), GFP_KERNEL); + if (!ce) + return -ENOMEM; + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("Couldn't enable parent clock\n"); + goto err_free; + } + + rate = clk_get_rate(clk); + if (!rate) { + pr_err("Couldn't get parent clock rate\n"); + ret = -EINVAL; + goto err_disable_clk; + } + + ce->timer.base = base; + ce->timer.ticks_per_jiffy = DIV_ROUND_UP(rate, HZ); + ce->timer.clk = clk; + ce->timer.clk_rate_cb.notifier_call = sun5i_rate_cb_clkevt; + ce->timer.clk_rate_cb.next = NULL; + + ret = clk_notifier_register(clk, &ce->timer.clk_rate_cb); + if (ret) { + pr_err("Unable to register clock notifier.\n"); + goto err_disable_clk; + } + + ce->clkevt.name = node->name; + ce->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT; + ce->clkevt.set_next_event = sun5i_clkevt_next_event; + ce->clkevt.set_state_shutdown = sun5i_clkevt_shutdown; + ce->clkevt.set_state_periodic = sun5i_clkevt_set_periodic; + ce->clkevt.set_state_oneshot = sun5i_clkevt_set_oneshot; + ce->clkevt.tick_resume = sun5i_clkevt_shutdown; + ce->clkevt.rating = 340; + ce->clkevt.irq = irq; + ce->clkevt.cpumask = cpu_possible_mask; + + /* Enable timer0 interrupt */ + val = readl(base + TIMER_IRQ_EN_REG); + writel(val | TIMER_IRQ_EN(0), base + TIMER_IRQ_EN_REG); + + clockevents_config_and_register(&ce->clkevt, rate, + TIMER_SYNC_TICKS, 0xffffffff); + + ret = request_irq(irq, sun5i_timer_interrupt, IRQF_TIMER | IRQF_IRQPOLL, + "sun5i_timer0", ce); + if (ret) { + pr_err("Unable to register interrupt\n"); + goto err_remove_notifier; + } + + return 0; + +err_remove_notifier: + clk_notifier_unregister(clk, &ce->timer.clk_rate_cb); +err_disable_clk: + clk_disable_unprepare(clk); +err_free: + kfree(ce); + return ret; +} + +static int __init sun5i_timer_init(struct device_node *node) +{ + struct reset_control *rstc; + void __iomem *timer_base; + struct clk *clk; + int irq, ret; + + timer_base = of_io_request_and_map(node, 0, of_node_full_name(node)); + if (IS_ERR(timer_base)) { + pr_err("Can't map registers\n"); + return PTR_ERR(timer_base); + } + + irq = irq_of_parse_and_map(node, 0); + if (irq <= 0) { + pr_err("Can't parse IRQ\n"); + return -EINVAL; + } + + clk = of_clk_get(node, 0); + if (IS_ERR(clk)) { + pr_err("Can't get timer clock\n"); + return PTR_ERR(clk); + } + + rstc = of_reset_control_get(node, NULL); + if (!IS_ERR(rstc)) + reset_control_deassert(rstc); + + ret = sun5i_setup_clocksource(node, timer_base, clk, irq); + if (ret) + return ret; + + return sun5i_setup_clockevent(node, timer_base, clk, irq); +} +TIMER_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer", + sun5i_timer_init); +TIMER_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer", + sun5i_timer_init); |