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path: root/drivers/clocksource/sh_tmu.c
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-rw-r--r--drivers/clocksource/sh_tmu.c682
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");