clocksource: Add a new timer-ingenic driver
This driver handles the TCU (Timer Counter Unit) present on the Ingenic
JZ47xx SoCs, and provides the kernel with a system timer, a clocksource
and a sched_clock.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-mips@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: od@zcrc.me
diff --git a/drivers/clocksource/ingenic-timer.c b/drivers/clocksource/ingenic-timer.c
new file mode 100644
index 0000000..4bbdb3d
--- /dev/null
+++ b/drivers/clocksource/ingenic-timer.c
@@ -0,0 +1,356 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ47xx SoCs TCU IRQ driver
+ * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/ingenic-tcu.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sched_clock.h>
+
+#include <dt-bindings/clock/ingenic,tcu.h>
+
+struct ingenic_soc_info {
+ unsigned int num_channels;
+};
+
+struct ingenic_tcu {
+ struct regmap *map;
+ struct clk *timer_clk, *cs_clk;
+ unsigned int timer_channel, cs_channel;
+ struct clock_event_device cevt;
+ struct clocksource cs;
+ char name[4];
+ unsigned long pwm_channels_mask;
+};
+
+static struct ingenic_tcu *ingenic_tcu;
+
+static u64 notrace ingenic_tcu_timer_read(void)
+{
+ struct ingenic_tcu *tcu = ingenic_tcu;
+ unsigned int count;
+
+ regmap_read(tcu->map, TCU_REG_TCNTc(tcu->cs_channel), &count);
+
+ return count;
+}
+
+static u64 notrace ingenic_tcu_timer_cs_read(struct clocksource *cs)
+{
+ return ingenic_tcu_timer_read();
+}
+
+static inline struct ingenic_tcu *to_ingenic_tcu(struct clock_event_device *evt)
+{
+ return container_of(evt, struct ingenic_tcu, cevt);
+}
+
+static int ingenic_tcu_cevt_set_state_shutdown(struct clock_event_device *evt)
+{
+ struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
+
+ regmap_write(tcu->map, TCU_REG_TECR, BIT(tcu->timer_channel));
+
+ return 0;
+}
+
+static int ingenic_tcu_cevt_set_next(unsigned long next,
+ struct clock_event_device *evt)
+{
+ struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
+
+ if (next > 0xffff)
+ return -EINVAL;
+
+ regmap_write(tcu->map, TCU_REG_TDFRc(tcu->timer_channel), next);
+ regmap_write(tcu->map, TCU_REG_TCNTc(tcu->timer_channel), 0);
+ regmap_write(tcu->map, TCU_REG_TESR, BIT(tcu->timer_channel));
+
+ return 0;
+}
+
+static irqreturn_t ingenic_tcu_cevt_cb(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = dev_id;
+ struct ingenic_tcu *tcu = to_ingenic_tcu(evt);
+
+ regmap_write(tcu->map, TCU_REG_TECR, BIT(tcu->timer_channel));
+
+ if (evt->event_handler)
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static struct clk * __init ingenic_tcu_get_clock(struct device_node *np, int id)
+{
+ struct of_phandle_args args;
+
+ args.np = np;
+ args.args_count = 1;
+ args.args[0] = id;
+
+ return of_clk_get_from_provider(&args);
+}
+
+static int __init ingenic_tcu_timer_init(struct device_node *np,
+ struct ingenic_tcu *tcu)
+{
+ unsigned int timer_virq, channel = tcu->timer_channel;
+ struct irq_domain *domain;
+ unsigned long rate;
+ int err;
+
+ tcu->timer_clk = ingenic_tcu_get_clock(np, channel);
+ if (IS_ERR(tcu->timer_clk))
+ return PTR_ERR(tcu->timer_clk);
+
+ err = clk_prepare_enable(tcu->timer_clk);
+ if (err)
+ goto err_clk_put;
+
+ rate = clk_get_rate(tcu->timer_clk);
+ if (!rate) {
+ err = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ domain = irq_find_host(np);
+ if (!domain) {
+ err = -ENODEV;
+ goto err_clk_disable;
+ }
+
+ timer_virq = irq_create_mapping(domain, channel);
+ if (!timer_virq) {
+ err = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ snprintf(tcu->name, sizeof(tcu->name), "TCU");
+
+ err = request_irq(timer_virq, ingenic_tcu_cevt_cb, IRQF_TIMER,
+ tcu->name, &tcu->cevt);
+ if (err)
+ goto err_irq_dispose_mapping;
+
+ tcu->cevt.cpumask = cpumask_of(smp_processor_id());
+ tcu->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
+ tcu->cevt.name = tcu->name;
+ tcu->cevt.rating = 200;
+ tcu->cevt.set_state_shutdown = ingenic_tcu_cevt_set_state_shutdown;
+ tcu->cevt.set_next_event = ingenic_tcu_cevt_set_next;
+
+ clockevents_config_and_register(&tcu->cevt, rate, 10, 0xffff);
+
+ return 0;
+
+err_irq_dispose_mapping:
+ irq_dispose_mapping(timer_virq);
+err_clk_disable:
+ clk_disable_unprepare(tcu->timer_clk);
+err_clk_put:
+ clk_put(tcu->timer_clk);
+ return err;
+}
+
+static int __init ingenic_tcu_clocksource_init(struct device_node *np,
+ struct ingenic_tcu *tcu)
+{
+ unsigned int channel = tcu->cs_channel;
+ struct clocksource *cs = &tcu->cs;
+ unsigned long rate;
+ int err;
+
+ tcu->cs_clk = ingenic_tcu_get_clock(np, channel);
+ if (IS_ERR(tcu->cs_clk))
+ return PTR_ERR(tcu->cs_clk);
+
+ err = clk_prepare_enable(tcu->cs_clk);
+ if (err)
+ goto err_clk_put;
+
+ rate = clk_get_rate(tcu->cs_clk);
+ if (!rate) {
+ err = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ /* Reset channel */
+ regmap_update_bits(tcu->map, TCU_REG_TCSRc(channel),
+ 0xffff & ~TCU_TCSR_RESERVED_BITS, 0);
+
+ /* Reset counter */
+ regmap_write(tcu->map, TCU_REG_TDFRc(channel), 0xffff);
+ regmap_write(tcu->map, TCU_REG_TCNTc(channel), 0);
+
+ /* Enable channel */
+ regmap_write(tcu->map, TCU_REG_TESR, BIT(channel));
+
+ cs->name = "ingenic-timer";
+ cs->rating = 200;
+ cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
+ cs->mask = CLOCKSOURCE_MASK(16);
+ cs->read = ingenic_tcu_timer_cs_read;
+
+ err = clocksource_register_hz(cs, rate);
+ if (err)
+ goto err_clk_disable;
+
+ return 0;
+
+err_clk_disable:
+ clk_disable_unprepare(tcu->cs_clk);
+err_clk_put:
+ clk_put(tcu->cs_clk);
+ return err;
+}
+
+static const struct ingenic_soc_info jz4740_soc_info = {
+ .num_channels = 8,
+};
+
+static const struct ingenic_soc_info jz4725b_soc_info = {
+ .num_channels = 6,
+};
+
+static const struct of_device_id ingenic_tcu_of_match[] = {
+ { .compatible = "ingenic,jz4740-tcu", .data = &jz4740_soc_info, },
+ { .compatible = "ingenic,jz4725b-tcu", .data = &jz4725b_soc_info, },
+ { .compatible = "ingenic,jz4770-tcu", .data = &jz4740_soc_info, },
+ { /* sentinel */ }
+};
+
+static int __init ingenic_tcu_init(struct device_node *np)
+{
+ const struct of_device_id *id = of_match_node(ingenic_tcu_of_match, np);
+ const struct ingenic_soc_info *soc_info = id->data;
+ struct ingenic_tcu *tcu;
+ struct regmap *map;
+ long rate;
+ int ret;
+
+ of_node_clear_flag(np, OF_POPULATED);
+
+ map = device_node_to_regmap(np);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
+ if (!tcu)
+ return -ENOMEM;
+
+ /* Enable all TCU channels for PWM use by default except channels 0/1 */
+ tcu->pwm_channels_mask = GENMASK(soc_info->num_channels - 1, 2);
+ of_property_read_u32(np, "ingenic,pwm-channels-mask",
+ (u32 *)&tcu->pwm_channels_mask);
+
+ /* Verify that we have at least two free channels */
+ if (hweight8(tcu->pwm_channels_mask) > soc_info->num_channels - 2) {
+ pr_crit("%s: Invalid PWM channel mask: 0x%02lx\n", __func__,
+ tcu->pwm_channels_mask);
+ ret = -EINVAL;
+ goto err_free_ingenic_tcu;
+ }
+
+ tcu->map = map;
+ ingenic_tcu = tcu;
+
+ tcu->timer_channel = find_first_zero_bit(&tcu->pwm_channels_mask,
+ soc_info->num_channels);
+ tcu->cs_channel = find_next_zero_bit(&tcu->pwm_channels_mask,
+ soc_info->num_channels,
+ tcu->timer_channel + 1);
+
+ ret = ingenic_tcu_clocksource_init(np, tcu);
+ if (ret) {
+ pr_crit("%s: Unable to init clocksource: %d\n", __func__, ret);
+ goto err_free_ingenic_tcu;
+ }
+
+ ret = ingenic_tcu_timer_init(np, tcu);
+ if (ret)
+ goto err_tcu_clocksource_cleanup;
+
+ /* Register the sched_clock at the end as there's no way to undo it */
+ rate = clk_get_rate(tcu->cs_clk);
+ sched_clock_register(ingenic_tcu_timer_read, 16, rate);
+
+ return 0;
+
+err_tcu_clocksource_cleanup:
+ clocksource_unregister(&tcu->cs);
+ clk_disable_unprepare(tcu->cs_clk);
+ clk_put(tcu->cs_clk);
+err_free_ingenic_tcu:
+ kfree(tcu);
+ return ret;
+}
+
+TIMER_OF_DECLARE(jz4740_tcu_intc, "ingenic,jz4740-tcu", ingenic_tcu_init);
+TIMER_OF_DECLARE(jz4725b_tcu_intc, "ingenic,jz4725b-tcu", ingenic_tcu_init);
+TIMER_OF_DECLARE(jz4770_tcu_intc, "ingenic,jz4770-tcu", ingenic_tcu_init);
+
+
+static int __init ingenic_tcu_probe(struct platform_device *pdev)
+{
+ platform_set_drvdata(pdev, ingenic_tcu);
+
+ return 0;
+}
+
+static int __maybe_unused ingenic_tcu_suspend(struct device *dev)
+{
+ struct ingenic_tcu *tcu = dev_get_drvdata(dev);
+
+ clk_disable(tcu->cs_clk);
+ clk_disable(tcu->timer_clk);
+ return 0;
+}
+
+static int __maybe_unused ingenic_tcu_resume(struct device *dev)
+{
+ struct ingenic_tcu *tcu = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_enable(tcu->timer_clk);
+ if (ret)
+ return ret;
+
+ ret = clk_enable(tcu->cs_clk);
+ if (ret) {
+ clk_disable(tcu->timer_clk);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops __maybe_unused ingenic_tcu_pm_ops = {
+ /* _noirq: We want the TCU clocks to be gated last / ungated first */
+ .suspend_noirq = ingenic_tcu_suspend,
+ .resume_noirq = ingenic_tcu_resume,
+};
+
+static struct platform_driver ingenic_tcu_driver = {
+ .driver = {
+ .name = "ingenic-tcu-timer",
+#ifdef CONFIG_PM_SLEEP
+ .pm = &ingenic_tcu_pm_ops,
+#endif
+ .of_match_table = ingenic_tcu_of_match,
+ },
+};
+builtin_platform_driver_probe(ingenic_tcu_driver, ingenic_tcu_probe);
