/* * SuperH Timer Support - TMU * * Copyright (C) 2009 Magnus Damm * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #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> 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 rate; 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; 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 */ ch->rate = clk_get_rate(ch->tmu->clk) / 4; 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 (ch->ced.mode == CLOCK_EVT_MODE_ONESHOT) 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 cycle_t 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) { __clocksource_updatefreq_hz(cs, ch->rate); 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); pm_genpd_syscore_poweroff(&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) { pm_genpd_syscore_poweron(&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); /* Register with dummy 1 Hz value, gets updated in ->enable() */ clocksource_register_hz(cs, 1); 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) { struct clock_event_device *ced = &ch->ced; sh_tmu_enable(ch); clockevents_config(ced, ch->rate); if (periodic) { ch->periodic = (ch->rate + HZ/2) / HZ; sh_tmu_set_next(ch, ch->periodic, 1); } } static void sh_tmu_clock_event_mode(enum clock_event_mode mode, struct clock_event_device *ced) { struct sh_tmu_channel *ch = ced_to_sh_tmu(ced); int disabled = 0; /* deal with old setting first */ switch (ced->mode) { case CLOCK_EVT_MODE_PERIODIC: case CLOCK_EVT_MODE_ONESHOT: sh_tmu_disable(ch); disabled = 1; break; default: break; } switch (mode) { case CLOCK_EVT_MODE_PERIODIC: dev_info(&ch->tmu->pdev->dev, "ch%u: used for periodic clock events\n", ch->index); sh_tmu_clock_event_start(ch, 1); break; case CLOCK_EVT_MODE_ONESHOT: dev_info(&ch->tmu->pdev->dev, "ch%u: used for oneshot clock events\n", ch->index); sh_tmu_clock_event_start(ch, 0); break; case CLOCK_EVT_MODE_UNUSED: if (!disabled) sh_tmu_disable(ch); break; case CLOCK_EVT_MODE_SHUTDOWN: default: break; } } 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(ced->mode != CLOCK_EVT_MODE_ONESHOT); /* 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) { pm_genpd_syscore_poweroff(&ced_to_sh_tmu(ced)->tmu->pdev->dev); } static void sh_tmu_clock_event_resume(struct clock_event_device *ced) { pm_genpd_syscore_poweron(&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 = cpumask_of(0); ced->set_next_event = sh_tmu_clock_event_next; ced->set_mode = sh_tmu_clock_event_mode; 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, 1, 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) { dev_err(&tmu->pdev->dev, "ch%u: failed to get irq\n", ch->index); 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_nocache(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; /* 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 = kzalloc(sizeof(*tmu->channels) * tmu->num_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_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_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); } early_platform_init("earlytimer", &sh_tmu_device_driver); subsys_initcall(sh_tmu_init); module_exit(sh_tmu_exit); MODULE_AUTHOR("Magnus Damm"); MODULE_DESCRIPTION("SuperH TMU Timer Driver"); MODULE_LICENSE("GPL v2");