/* * SuperH Timer Support - MTU2 * * 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/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> struct sh_mtu2_device; struct sh_mtu2_channel { struct sh_mtu2_device *mtu; unsigned int index; void __iomem *base; struct clock_event_device ced; }; struct sh_mtu2_device { struct platform_device *pdev; void __iomem *mapbase; struct clk *clk; raw_spinlock_t lock; /* Protect the shared registers */ struct sh_mtu2_channel *channels; unsigned int num_channels; bool has_clockevent; }; #define TSTR -1 /* shared register */ #define TCR 0 /* channel register */ #define TMDR 1 /* channel register */ #define TIOR 2 /* channel register */ #define TIER 3 /* channel register */ #define TSR 4 /* channel register */ #define TCNT 5 /* channel register */ #define TGR 6 /* channel register */ #define TCR_CCLR_NONE (0 << 5) #define TCR_CCLR_TGRA (1 << 5) #define TCR_CCLR_TGRB (2 << 5) #define TCR_CCLR_SYNC (3 << 5) #define TCR_CCLR_TGRC (5 << 5) #define TCR_CCLR_TGRD (6 << 5) #define TCR_CCLR_MASK (7 << 5) #define TCR_CKEG_RISING (0 << 3) #define TCR_CKEG_FALLING (1 << 3) #define TCR_CKEG_BOTH (2 << 3) #define TCR_CKEG_MASK (3 << 3) /* Values 4 to 7 are channel-dependent */ #define TCR_TPSC_P1 (0 << 0) #define TCR_TPSC_P4 (1 << 0) #define TCR_TPSC_P16 (2 << 0) #define TCR_TPSC_P64 (3 << 0) #define TCR_TPSC_CH0_TCLKA (4 << 0) #define TCR_TPSC_CH0_TCLKB (5 << 0) #define TCR_TPSC_CH0_TCLKC (6 << 0) #define TCR_TPSC_CH0_TCLKD (7 << 0) #define TCR_TPSC_CH1_TCLKA (4 << 0) #define TCR_TPSC_CH1_TCLKB (5 << 0) #define TCR_TPSC_CH1_P256 (6 << 0) #define TCR_TPSC_CH1_TCNT2 (7 << 0) #define TCR_TPSC_CH2_TCLKA (4 << 0) #define TCR_TPSC_CH2_TCLKB (5 << 0) #define TCR_TPSC_CH2_TCLKC (6 << 0) #define TCR_TPSC_CH2_P1024 (7 << 0) #define TCR_TPSC_CH34_P256 (4 << 0) #define TCR_TPSC_CH34_P1024 (5 << 0) #define TCR_TPSC_CH34_TCLKA (6 << 0) #define TCR_TPSC_CH34_TCLKB (7 << 0) #define TCR_TPSC_MASK (7 << 0) #define TMDR_BFE (1 << 6) #define TMDR_BFB (1 << 5) #define TMDR_BFA (1 << 4) #define TMDR_MD_NORMAL (0 << 0) #define TMDR_MD_PWM_1 (2 << 0) #define TMDR_MD_PWM_2 (3 << 0) #define TMDR_MD_PHASE_1 (4 << 0) #define TMDR_MD_PHASE_2 (5 << 0) #define TMDR_MD_PHASE_3 (6 << 0) #define TMDR_MD_PHASE_4 (7 << 0) #define TMDR_MD_PWM_SYNC (8 << 0) #define TMDR_MD_PWM_COMP_CREST (13 << 0) #define TMDR_MD_PWM_COMP_TROUGH (14 << 0) #define TMDR_MD_PWM_COMP_BOTH (15 << 0) #define TMDR_MD_MASK (15 << 0) #define TIOC_IOCH(n) ((n) << 4) #define TIOC_IOCL(n) ((n) << 0) #define TIOR_OC_RETAIN (0 << 0) #define TIOR_OC_0_CLEAR (1 << 0) #define TIOR_OC_0_SET (2 << 0) #define TIOR_OC_0_TOGGLE (3 << 0) #define TIOR_OC_1_CLEAR (5 << 0) #define TIOR_OC_1_SET (6 << 0) #define TIOR_OC_1_TOGGLE (7 << 0) #define TIOR_IC_RISING (8 << 0) #define TIOR_IC_FALLING (9 << 0) #define TIOR_IC_BOTH (10 << 0) #define TIOR_IC_TCNT (12 << 0) #define TIOR_MASK (15 << 0) #define TIER_TTGE (1 << 7) #define TIER_TTGE2 (1 << 6) #define TIER_TCIEU (1 << 5) #define TIER_TCIEV (1 << 4) #define TIER_TGIED (1 << 3) #define TIER_TGIEC (1 << 2) #define TIER_TGIEB (1 << 1) #define TIER_TGIEA (1 << 0) #define TSR_TCFD (1 << 7) #define TSR_TCFU (1 << 5) #define TSR_TCFV (1 << 4) #define TSR_TGFD (1 << 3) #define TSR_TGFC (1 << 2) #define TSR_TGFB (1 << 1) #define TSR_TGFA (1 << 0) static unsigned long mtu2_reg_offs[] = { [TCR] = 0, [TMDR] = 1, [TIOR] = 2, [TIER] = 4, [TSR] = 5, [TCNT] = 6, [TGR] = 8, }; static inline unsigned long sh_mtu2_read(struct sh_mtu2_channel *ch, int reg_nr) { unsigned long offs; if (reg_nr == TSTR) return ioread8(ch->mtu->mapbase + 0x280); offs = mtu2_reg_offs[reg_nr]; if ((reg_nr == TCNT) || (reg_nr == TGR)) return ioread16(ch->base + offs); else return ioread8(ch->base + offs); } static inline void sh_mtu2_write(struct sh_mtu2_channel *ch, int reg_nr, unsigned long value) { unsigned long offs; if (reg_nr == TSTR) return iowrite8(value, ch->mtu->mapbase + 0x280); offs = mtu2_reg_offs[reg_nr]; if ((reg_nr == TCNT) || (reg_nr == TGR)) iowrite16(value, ch->base + offs); else iowrite8(value, ch->base + offs); } static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start) { unsigned long flags, value; /* start stop register shared by multiple timer channels */ raw_spin_lock_irqsave(&ch->mtu->lock, flags); value = sh_mtu2_read(ch, TSTR); if (start) value |= 1 << ch->index; else value &= ~(1 << ch->index); sh_mtu2_write(ch, TSTR, value); raw_spin_unlock_irqrestore(&ch->mtu->lock, flags); } static int sh_mtu2_enable(struct sh_mtu2_channel *ch) { unsigned long periodic; unsigned long rate; int ret; pm_runtime_get_sync(&ch->mtu->pdev->dev); dev_pm_syscore_device(&ch->mtu->pdev->dev, true); /* enable clock */ ret = clk_enable(ch->mtu->clk); if (ret) { dev_err(&ch->mtu->pdev->dev, "ch%u: cannot enable clock\n", ch->index); return ret; } /* make sure channel is disabled */ sh_mtu2_start_stop_ch(ch, 0); rate = clk_get_rate(ch->mtu->clk) / 64; periodic = (rate + HZ/2) / HZ; /* * "Periodic Counter Operation" * Clear on TGRA compare match, divide clock by 64. */ sh_mtu2_write(ch, TCR, TCR_CCLR_TGRA | TCR_TPSC_P64); sh_mtu2_write(ch, TIOR, TIOC_IOCH(TIOR_OC_0_CLEAR) | TIOC_IOCL(TIOR_OC_0_CLEAR)); sh_mtu2_write(ch, TGR, periodic); sh_mtu2_write(ch, TCNT, 0); sh_mtu2_write(ch, TMDR, TMDR_MD_NORMAL); sh_mtu2_write(ch, TIER, TIER_TGIEA); /* enable channel */ sh_mtu2_start_stop_ch(ch, 1); return 0; } static void sh_mtu2_disable(struct sh_mtu2_channel *ch) { /* disable channel */ sh_mtu2_start_stop_ch(ch, 0); /* stop clock */ clk_disable(ch->mtu->clk); dev_pm_syscore_device(&ch->mtu->pdev->dev, false); pm_runtime_put(&ch->mtu->pdev->dev); } static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id) { struct sh_mtu2_channel *ch = dev_id; /* acknowledge interrupt */ sh_mtu2_read(ch, TSR); sh_mtu2_write(ch, TSR, ~TSR_TGFA); /* notify clockevent layer */ ch->ced.event_handler(&ch->ced); return IRQ_HANDLED; } static struct sh_mtu2_channel *ced_to_sh_mtu2(struct clock_event_device *ced) { return container_of(ced, struct sh_mtu2_channel, ced); } static int sh_mtu2_clock_event_shutdown(struct clock_event_device *ced) { struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced); if (clockevent_state_periodic(ced)) sh_mtu2_disable(ch); return 0; } static int sh_mtu2_clock_event_set_periodic(struct clock_event_device *ced) { struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced); if (clockevent_state_periodic(ced)) sh_mtu2_disable(ch); dev_info(&ch->mtu->pdev->dev, "ch%u: used for periodic clock events\n", ch->index); sh_mtu2_enable(ch); return 0; } static void sh_mtu2_clock_event_suspend(struct clock_event_device *ced) { pm_genpd_syscore_poweroff(&ced_to_sh_mtu2(ced)->mtu->pdev->dev); } static void sh_mtu2_clock_event_resume(struct clock_event_device *ced) { pm_genpd_syscore_poweron(&ced_to_sh_mtu2(ced)->mtu->pdev->dev); } static void sh_mtu2_register_clockevent(struct sh_mtu2_channel *ch, const char *name) { struct clock_event_device *ced = &ch->ced; ced->name = name; ced->features = CLOCK_EVT_FEAT_PERIODIC; ced->rating = 200; ced->cpumask = cpu_possible_mask; ced->set_state_shutdown = sh_mtu2_clock_event_shutdown; ced->set_state_periodic = sh_mtu2_clock_event_set_periodic; ced->suspend = sh_mtu2_clock_event_suspend; ced->resume = sh_mtu2_clock_event_resume; dev_info(&ch->mtu->pdev->dev, "ch%u: used for clock events\n", ch->index); clockevents_register_device(ced); } static int sh_mtu2_register(struct sh_mtu2_channel *ch, const char *name) { ch->mtu->has_clockevent = true; sh_mtu2_register_clockevent(ch, name); return 0; } static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index, struct sh_mtu2_device *mtu) { static const unsigned int channel_offsets[] = { 0x300, 0x380, 0x000, }; char name[6]; int irq; int ret; ch->mtu = mtu; sprintf(name, "tgi%ua", index); irq = platform_get_irq_byname(mtu->pdev, name); if (irq < 0) { /* Skip channels with no declared interrupt. */ return 0; } ret = request_irq(irq, sh_mtu2_interrupt, IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, dev_name(&ch->mtu->pdev->dev), ch); if (ret) { dev_err(&ch->mtu->pdev->dev, "ch%u: failed to request irq %d\n", index, irq); return ret; } ch->base = mtu->mapbase + channel_offsets[index]; ch->index = index; return sh_mtu2_register(ch, dev_name(&mtu->pdev->dev)); } static int sh_mtu2_map_memory(struct sh_mtu2_device *mtu) { struct resource *res; res = platform_get_resource(mtu->pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&mtu->pdev->dev, "failed to get I/O memory\n"); return -ENXIO; } mtu->mapbase = ioremap_nocache(res->start, resource_size(res)); if (mtu->mapbase == NULL) return -ENXIO; return 0; } static int sh_mtu2_setup(struct sh_mtu2_device *mtu, struct platform_device *pdev) { unsigned int i; int ret; mtu->pdev = pdev; raw_spin_lock_init(&mtu->lock); /* Get hold of clock. */ mtu->clk = clk_get(&mtu->pdev->dev, "fck"); if (IS_ERR(mtu->clk)) { dev_err(&mtu->pdev->dev, "cannot get clock\n"); return PTR_ERR(mtu->clk); } ret = clk_prepare(mtu->clk); if (ret < 0) goto err_clk_put; /* Map the memory resource. */ ret = sh_mtu2_map_memory(mtu); if (ret < 0) { dev_err(&mtu->pdev->dev, "failed to remap I/O memory\n"); goto err_clk_unprepare; } /* Allocate and setup the channels. */ mtu->num_channels = 3; mtu->channels = kzalloc(sizeof(*mtu->channels) * mtu->num_channels, GFP_KERNEL); if (mtu->channels == NULL) { ret = -ENOMEM; goto err_unmap; } for (i = 0; i < mtu->num_channels; ++i) { ret = sh_mtu2_setup_channel(&mtu->channels[i], i, mtu); if (ret < 0) goto err_unmap; } platform_set_drvdata(pdev, mtu); return 0; err_unmap: kfree(mtu->channels); iounmap(mtu->mapbase); err_clk_unprepare: clk_unprepare(mtu->clk); err_clk_put: clk_put(mtu->clk); return ret; } static int sh_mtu2_probe(struct platform_device *pdev) { struct sh_mtu2_device *mtu = platform_get_drvdata(pdev); int ret; if (!is_early_platform_device(pdev)) { pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); } if (mtu) { dev_info(&pdev->dev, "kept as earlytimer\n"); goto out; } mtu = kzalloc(sizeof(*mtu), GFP_KERNEL); if (mtu == NULL) return -ENOMEM; ret = sh_mtu2_setup(mtu, pdev); if (ret) { kfree(mtu); pm_runtime_idle(&pdev->dev); return ret; } if (is_early_platform_device(pdev)) return 0; out: if (mtu->has_clockevent) pm_runtime_irq_safe(&pdev->dev); else pm_runtime_idle(&pdev->dev); return 0; } static int sh_mtu2_remove(struct platform_device *pdev) { return -EBUSY; /* cannot unregister clockevent */ } static const struct platform_device_id sh_mtu2_id_table[] = { { "sh-mtu2", 0 }, { }, }; MODULE_DEVICE_TABLE(platform, sh_mtu2_id_table); static const struct of_device_id sh_mtu2_of_table[] __maybe_unused = { { .compatible = "renesas,mtu2" }, { } }; MODULE_DEVICE_TABLE(of, sh_mtu2_of_table); static struct platform_driver sh_mtu2_device_driver = { .probe = sh_mtu2_probe, .remove = sh_mtu2_remove, .driver = { .name = "sh_mtu2", .of_match_table = of_match_ptr(sh_mtu2_of_table), }, .id_table = sh_mtu2_id_table, }; static int __init sh_mtu2_init(void) { return platform_driver_register(&sh_mtu2_device_driver); } static void __exit sh_mtu2_exit(void) { platform_driver_unregister(&sh_mtu2_device_driver); } early_platform_init("earlytimer", &sh_mtu2_device_driver); subsys_initcall(sh_mtu2_init); module_exit(sh_mtu2_exit); MODULE_AUTHOR("Magnus Damm"); MODULE_DESCRIPTION("SuperH MTU2 Timer Driver"); MODULE_LICENSE("GPL v2");