Initial import

1 files changed, 687 insertions, 0 deletions

diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c
new file mode 100644
index 000000000..b6b8fa3cd
--- /dev/null
+++ b/drivers/clocksource/sh_tmu.c
@@ -0,0 +1,687 @@
+/*
+ * 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_update_freq_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 = cpu_possible_mask;
+	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");