diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clocksource/sh_tmu.c | 682 |
1 files changed, 682 insertions, 0 deletions
diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c new file mode 100644 index 000000000..b00dec065 --- /dev/null +++ b/drivers/clocksource/sh_tmu.c @@ -0,0 +1,682 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * SuperH Timer Support - TMU + * + * Copyright (C) 2009 Magnus Damm + */ + +#include <linux/clk.h> +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm_domain.h> +#include <linux/pm_runtime.h> +#include <linux/sh_timer.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#ifdef CONFIG_SUPERH +#include <asm/platform_early.h> +#endif + +enum sh_tmu_model { + SH_TMU, + SH_TMU_SH3, +}; + +struct sh_tmu_device; + +struct sh_tmu_channel { + struct sh_tmu_device *tmu; + unsigned int index; + + void __iomem *base; + int irq; + + unsigned long periodic; + struct clock_event_device ced; + struct clocksource cs; + bool cs_enabled; + unsigned int enable_count; +}; + +struct sh_tmu_device { + struct platform_device *pdev; + + void __iomem *mapbase; + struct clk *clk; + unsigned long rate; + + enum sh_tmu_model model; + + raw_spinlock_t lock; /* Protect the shared start/stop register */ + + struct sh_tmu_channel *channels; + unsigned int num_channels; + + bool has_clockevent; + bool has_clocksource; +}; + +#define TSTR -1 /* shared register */ +#define TCOR 0 /* channel register */ +#define TCNT 1 /* channel register */ +#define TCR 2 /* channel register */ + +#define TCR_UNF (1 << 8) +#define TCR_UNIE (1 << 5) +#define TCR_TPSC_CLK4 (0 << 0) +#define TCR_TPSC_CLK16 (1 << 0) +#define TCR_TPSC_CLK64 (2 << 0) +#define TCR_TPSC_CLK256 (3 << 0) +#define TCR_TPSC_CLK1024 (4 << 0) +#define TCR_TPSC_MASK (7 << 0) + +static inline unsigned long sh_tmu_read(struct sh_tmu_channel *ch, int reg_nr) +{ + unsigned long offs; + + if (reg_nr == TSTR) { + switch (ch->tmu->model) { + case SH_TMU_SH3: + return ioread8(ch->tmu->mapbase + 2); + case SH_TMU: + return ioread8(ch->tmu->mapbase + 4); + } + } + + offs = reg_nr << 2; + + if (reg_nr == TCR) + return ioread16(ch->base + offs); + else + return ioread32(ch->base + offs); +} + +static inline void sh_tmu_write(struct sh_tmu_channel *ch, int reg_nr, + unsigned long value) +{ + unsigned long offs; + + if (reg_nr == TSTR) { + switch (ch->tmu->model) { + case SH_TMU_SH3: + return iowrite8(value, ch->tmu->mapbase + 2); + case SH_TMU: + return iowrite8(value, ch->tmu->mapbase + 4); + } + } + + offs = reg_nr << 2; + + if (reg_nr == TCR) + iowrite16(value, ch->base + offs); + else + iowrite32(value, ch->base + offs); +} + +static void sh_tmu_start_stop_ch(struct sh_tmu_channel *ch, int start) +{ + unsigned long flags, value; + + /* start stop register shared by multiple timer channels */ + raw_spin_lock_irqsave(&ch->tmu->lock, flags); + value = sh_tmu_read(ch, TSTR); + + if (start) + value |= 1 << ch->index; + else + value &= ~(1 << ch->index); + + sh_tmu_write(ch, TSTR, value); + raw_spin_unlock_irqrestore(&ch->tmu->lock, flags); +} + +static int __sh_tmu_enable(struct sh_tmu_channel *ch) +{ + int ret; + + /* enable clock */ + ret = clk_enable(ch->tmu->clk); + if (ret) { + dev_err(&ch->tmu->pdev->dev, "ch%u: cannot enable clock\n", + ch->index); + return ret; + } + + /* make sure channel is disabled */ + sh_tmu_start_stop_ch(ch, 0); + + /* maximum timeout */ + sh_tmu_write(ch, TCOR, 0xffffffff); + sh_tmu_write(ch, TCNT, 0xffffffff); + + /* configure channel to parent clock / 4, irq off */ + sh_tmu_write(ch, TCR, TCR_TPSC_CLK4); + + /* enable channel */ + sh_tmu_start_stop_ch(ch, 1); + + return 0; +} + +static int sh_tmu_enable(struct sh_tmu_channel *ch) +{ + if (ch->enable_count++ > 0) + return 0; + + pm_runtime_get_sync(&ch->tmu->pdev->dev); + dev_pm_syscore_device(&ch->tmu->pdev->dev, true); + + return __sh_tmu_enable(ch); +} + +static void __sh_tmu_disable(struct sh_tmu_channel *ch) +{ + /* disable channel */ + sh_tmu_start_stop_ch(ch, 0); + + /* disable interrupts in TMU block */ + sh_tmu_write(ch, TCR, TCR_TPSC_CLK4); + + /* stop clock */ + clk_disable(ch->tmu->clk); +} + +static void sh_tmu_disable(struct sh_tmu_channel *ch) +{ + if (WARN_ON(ch->enable_count == 0)) + return; + + if (--ch->enable_count > 0) + return; + + __sh_tmu_disable(ch); + + dev_pm_syscore_device(&ch->tmu->pdev->dev, false); + pm_runtime_put(&ch->tmu->pdev->dev); +} + +static void sh_tmu_set_next(struct sh_tmu_channel *ch, unsigned long delta, + int periodic) +{ + /* stop timer */ + sh_tmu_start_stop_ch(ch, 0); + + /* acknowledge interrupt */ + sh_tmu_read(ch, TCR); + + /* enable interrupt */ + sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4); + + /* reload delta value in case of periodic timer */ + if (periodic) + sh_tmu_write(ch, TCOR, delta); + else + sh_tmu_write(ch, TCOR, 0xffffffff); + + sh_tmu_write(ch, TCNT, delta); + + /* start timer */ + sh_tmu_start_stop_ch(ch, 1); +} + +static irqreturn_t sh_tmu_interrupt(int irq, void *dev_id) +{ + struct sh_tmu_channel *ch = dev_id; + + /* disable or acknowledge interrupt */ + if (clockevent_state_oneshot(&ch->ced)) + sh_tmu_write(ch, TCR, TCR_TPSC_CLK4); + else + sh_tmu_write(ch, TCR, TCR_UNIE | TCR_TPSC_CLK4); + + /* notify clockevent layer */ + ch->ced.event_handler(&ch->ced); + return IRQ_HANDLED; +} + +static struct sh_tmu_channel *cs_to_sh_tmu(struct clocksource *cs) +{ + return container_of(cs, struct sh_tmu_channel, cs); +} + +static u64 sh_tmu_clocksource_read(struct clocksource *cs) +{ + struct sh_tmu_channel *ch = cs_to_sh_tmu(cs); + + return sh_tmu_read(ch, TCNT) ^ 0xffffffff; +} + +static int sh_tmu_clocksource_enable(struct clocksource *cs) +{ + struct sh_tmu_channel *ch = cs_to_sh_tmu(cs); + int ret; + + if (WARN_ON(ch->cs_enabled)) + return 0; + + ret = sh_tmu_enable(ch); + if (!ret) + ch->cs_enabled = true; + + return ret; +} + +static void sh_tmu_clocksource_disable(struct clocksource *cs) +{ + struct sh_tmu_channel *ch = cs_to_sh_tmu(cs); + + if (WARN_ON(!ch->cs_enabled)) + return; + + sh_tmu_disable(ch); + ch->cs_enabled = false; +} + +static void sh_tmu_clocksource_suspend(struct clocksource *cs) +{ + struct sh_tmu_channel *ch = cs_to_sh_tmu(cs); + + if (!ch->cs_enabled) + return; + + if (--ch->enable_count == 0) { + __sh_tmu_disable(ch); + dev_pm_genpd_suspend(&ch->tmu->pdev->dev); + } +} + +static void sh_tmu_clocksource_resume(struct clocksource *cs) +{ + struct sh_tmu_channel *ch = cs_to_sh_tmu(cs); + + if (!ch->cs_enabled) + return; + + if (ch->enable_count++ == 0) { + dev_pm_genpd_resume(&ch->tmu->pdev->dev); + __sh_tmu_enable(ch); + } +} + +static int sh_tmu_register_clocksource(struct sh_tmu_channel *ch, + const char *name) +{ + struct clocksource *cs = &ch->cs; + + cs->name = name; + cs->rating = 200; + cs->read = sh_tmu_clocksource_read; + cs->enable = sh_tmu_clocksource_enable; + cs->disable = sh_tmu_clocksource_disable; + cs->suspend = sh_tmu_clocksource_suspend; + cs->resume = sh_tmu_clocksource_resume; + cs->mask = CLOCKSOURCE_MASK(32); + cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; + + dev_info(&ch->tmu->pdev->dev, "ch%u: used as clock source\n", + ch->index); + + clocksource_register_hz(cs, ch->tmu->rate); + return 0; +} + +static struct sh_tmu_channel *ced_to_sh_tmu(struct clock_event_device *ced) +{ + return container_of(ced, struct sh_tmu_channel, ced); +} + +static void sh_tmu_clock_event_start(struct sh_tmu_channel *ch, int periodic) +{ + sh_tmu_enable(ch); + + if (periodic) { + ch->periodic = (ch->tmu->rate + HZ/2) / HZ; + sh_tmu_set_next(ch, ch->periodic, 1); + } +} + +static int sh_tmu_clock_event_shutdown(struct clock_event_device *ced) +{ + struct sh_tmu_channel *ch = ced_to_sh_tmu(ced); + + if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced)) + sh_tmu_disable(ch); + return 0; +} + +static int sh_tmu_clock_event_set_state(struct clock_event_device *ced, + int periodic) +{ + struct sh_tmu_channel *ch = ced_to_sh_tmu(ced); + + /* deal with old setting first */ + if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced)) + sh_tmu_disable(ch); + + dev_info(&ch->tmu->pdev->dev, "ch%u: used for %s clock events\n", + ch->index, periodic ? "periodic" : "oneshot"); + sh_tmu_clock_event_start(ch, periodic); + return 0; +} + +static int sh_tmu_clock_event_set_oneshot(struct clock_event_device *ced) +{ + return sh_tmu_clock_event_set_state(ced, 0); +} + +static int sh_tmu_clock_event_set_periodic(struct clock_event_device *ced) +{ + return sh_tmu_clock_event_set_state(ced, 1); +} + +static int sh_tmu_clock_event_next(unsigned long delta, + struct clock_event_device *ced) +{ + struct sh_tmu_channel *ch = ced_to_sh_tmu(ced); + + BUG_ON(!clockevent_state_oneshot(ced)); + + /* program new delta value */ + sh_tmu_set_next(ch, delta, 0); + return 0; +} + +static void sh_tmu_clock_event_suspend(struct clock_event_device *ced) +{ + dev_pm_genpd_suspend(&ced_to_sh_tmu(ced)->tmu->pdev->dev); +} + +static void sh_tmu_clock_event_resume(struct clock_event_device *ced) +{ + dev_pm_genpd_resume(&ced_to_sh_tmu(ced)->tmu->pdev->dev); +} + +static void sh_tmu_register_clockevent(struct sh_tmu_channel *ch, + const char *name) +{ + struct clock_event_device *ced = &ch->ced; + int ret; + + ced->name = name; + ced->features = CLOCK_EVT_FEAT_PERIODIC; + ced->features |= CLOCK_EVT_FEAT_ONESHOT; + ced->rating = 200; + ced->cpumask = cpu_possible_mask; + ced->set_next_event = sh_tmu_clock_event_next; + ced->set_state_shutdown = sh_tmu_clock_event_shutdown; + ced->set_state_periodic = sh_tmu_clock_event_set_periodic; + ced->set_state_oneshot = sh_tmu_clock_event_set_oneshot; + ced->suspend = sh_tmu_clock_event_suspend; + ced->resume = sh_tmu_clock_event_resume; + + dev_info(&ch->tmu->pdev->dev, "ch%u: used for clock events\n", + ch->index); + + clockevents_config_and_register(ced, ch->tmu->rate, 0x300, 0xffffffff); + + ret = request_irq(ch->irq, sh_tmu_interrupt, + IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, + dev_name(&ch->tmu->pdev->dev), ch); + if (ret) { + dev_err(&ch->tmu->pdev->dev, "ch%u: failed to request irq %d\n", + ch->index, ch->irq); + return; + } +} + +static int sh_tmu_register(struct sh_tmu_channel *ch, const char *name, + bool clockevent, bool clocksource) +{ + if (clockevent) { + ch->tmu->has_clockevent = true; + sh_tmu_register_clockevent(ch, name); + } else if (clocksource) { + ch->tmu->has_clocksource = true; + sh_tmu_register_clocksource(ch, name); + } + + return 0; +} + +static int sh_tmu_channel_setup(struct sh_tmu_channel *ch, unsigned int index, + bool clockevent, bool clocksource, + struct sh_tmu_device *tmu) +{ + /* Skip unused channels. */ + if (!clockevent && !clocksource) + return 0; + + ch->tmu = tmu; + ch->index = index; + + if (tmu->model == SH_TMU_SH3) + ch->base = tmu->mapbase + 4 + ch->index * 12; + else + ch->base = tmu->mapbase + 8 + ch->index * 12; + + ch->irq = platform_get_irq(tmu->pdev, index); + if (ch->irq < 0) + return ch->irq; + + ch->cs_enabled = false; + ch->enable_count = 0; + + return sh_tmu_register(ch, dev_name(&tmu->pdev->dev), + clockevent, clocksource); +} + +static int sh_tmu_map_memory(struct sh_tmu_device *tmu) +{ + struct resource *res; + + res = platform_get_resource(tmu->pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&tmu->pdev->dev, "failed to get I/O memory\n"); + return -ENXIO; + } + + tmu->mapbase = ioremap(res->start, resource_size(res)); + if (tmu->mapbase == NULL) + return -ENXIO; + + return 0; +} + +static int sh_tmu_parse_dt(struct sh_tmu_device *tmu) +{ + struct device_node *np = tmu->pdev->dev.of_node; + + tmu->model = SH_TMU; + tmu->num_channels = 3; + + of_property_read_u32(np, "#renesas,channels", &tmu->num_channels); + + if (tmu->num_channels != 2 && tmu->num_channels != 3) { + dev_err(&tmu->pdev->dev, "invalid number of channels %u\n", + tmu->num_channels); + return -EINVAL; + } + + return 0; +} + +static int sh_tmu_setup(struct sh_tmu_device *tmu, struct platform_device *pdev) +{ + unsigned int i; + int ret; + + tmu->pdev = pdev; + + raw_spin_lock_init(&tmu->lock); + + if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) { + ret = sh_tmu_parse_dt(tmu); + if (ret < 0) + return ret; + } else if (pdev->dev.platform_data) { + const struct platform_device_id *id = pdev->id_entry; + struct sh_timer_config *cfg = pdev->dev.platform_data; + + tmu->model = id->driver_data; + tmu->num_channels = hweight8(cfg->channels_mask); + } else { + dev_err(&tmu->pdev->dev, "missing platform data\n"); + return -ENXIO; + } + + /* Get hold of clock. */ + tmu->clk = clk_get(&tmu->pdev->dev, "fck"); + if (IS_ERR(tmu->clk)) { + dev_err(&tmu->pdev->dev, "cannot get clock\n"); + return PTR_ERR(tmu->clk); + } + + ret = clk_prepare(tmu->clk); + if (ret < 0) + goto err_clk_put; + + /* Determine clock rate. */ + ret = clk_enable(tmu->clk); + if (ret < 0) + goto err_clk_unprepare; + + tmu->rate = clk_get_rate(tmu->clk) / 4; + clk_disable(tmu->clk); + + /* Map the memory resource. */ + ret = sh_tmu_map_memory(tmu); + if (ret < 0) { + dev_err(&tmu->pdev->dev, "failed to remap I/O memory\n"); + goto err_clk_unprepare; + } + + /* Allocate and setup the channels. */ + tmu->channels = kcalloc(tmu->num_channels, sizeof(*tmu->channels), + GFP_KERNEL); + if (tmu->channels == NULL) { + ret = -ENOMEM; + goto err_unmap; + } + + /* + * Use the first channel as a clock event device and the second channel + * as a clock source. + */ + for (i = 0; i < tmu->num_channels; ++i) { + ret = sh_tmu_channel_setup(&tmu->channels[i], i, + i == 0, i == 1, tmu); + if (ret < 0) + goto err_unmap; + } + + platform_set_drvdata(pdev, tmu); + + return 0; + +err_unmap: + kfree(tmu->channels); + iounmap(tmu->mapbase); +err_clk_unprepare: + clk_unprepare(tmu->clk); +err_clk_put: + clk_put(tmu->clk); + return ret; +} + +static int sh_tmu_probe(struct platform_device *pdev) +{ + struct sh_tmu_device *tmu = platform_get_drvdata(pdev); + int ret; + + if (!is_sh_early_platform_device(pdev)) { + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + } + + if (tmu) { + dev_info(&pdev->dev, "kept as earlytimer\n"); + goto out; + } + + tmu = kzalloc(sizeof(*tmu), GFP_KERNEL); + if (tmu == NULL) + return -ENOMEM; + + ret = sh_tmu_setup(tmu, pdev); + if (ret) { + kfree(tmu); + pm_runtime_idle(&pdev->dev); + return ret; + } + + if (is_sh_early_platform_device(pdev)) + return 0; + + out: + if (tmu->has_clockevent || tmu->has_clocksource) + pm_runtime_irq_safe(&pdev->dev); + else + pm_runtime_idle(&pdev->dev); + + return 0; +} + +static int sh_tmu_remove(struct platform_device *pdev) +{ + return -EBUSY; /* cannot unregister clockevent and clocksource */ +} + +static const struct platform_device_id sh_tmu_id_table[] = { + { "sh-tmu", SH_TMU }, + { "sh-tmu-sh3", SH_TMU_SH3 }, + { } +}; +MODULE_DEVICE_TABLE(platform, sh_tmu_id_table); + +static const struct of_device_id sh_tmu_of_table[] __maybe_unused = { + { .compatible = "renesas,tmu" }, + { } +}; +MODULE_DEVICE_TABLE(of, sh_tmu_of_table); + +static struct platform_driver sh_tmu_device_driver = { + .probe = sh_tmu_probe, + .remove = sh_tmu_remove, + .driver = { + .name = "sh_tmu", + .of_match_table = of_match_ptr(sh_tmu_of_table), + }, + .id_table = sh_tmu_id_table, +}; + +static int __init sh_tmu_init(void) +{ + return platform_driver_register(&sh_tmu_device_driver); +} + +static void __exit sh_tmu_exit(void) +{ + platform_driver_unregister(&sh_tmu_device_driver); +} + +#ifdef CONFIG_SUPERH +sh_early_platform_init("earlytimer", &sh_tmu_device_driver); +#endif + +subsys_initcall(sh_tmu_init); +module_exit(sh_tmu_exit); + +MODULE_AUTHOR("Magnus Damm"); +MODULE_DESCRIPTION("SuperH TMU Timer Driver"); +MODULE_LICENSE("GPL v2"); |