clocksource: Add a new timer-ingenic driver
authorPaul Cercueil <paul@crapouillou.net>
Wed, 24 Jul 2019 17:16:09 +0000 (13:16 -0400)
committerPaul Burton <paul.burton@mips.com>
Thu, 8 Aug 2019 22:30:08 +0000 (15:30 -0700)
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
drivers/clocksource/Kconfig
drivers/clocksource/Makefile
drivers/clocksource/ingenic-timer.c [new file with mode: 0644]

index 5e9317d..a9cdc2c 100644 (file)
@@ -685,4 +685,15 @@ config MILBEAUT_TIMER
        help
          Enables the support for Milbeaut timer driver.
 
+config INGENIC_TIMER
+       bool "Clocksource/timer using the TCU in Ingenic JZ SoCs"
+       default MACH_INGENIC
+       depends on MIPS || COMPILE_TEST
+       depends on COMMON_CLK
+       select MFD_SYSCON
+       select TIMER_OF
+       select IRQ_DOMAIN
+       help
+         Support for the timer/counter unit of the Ingenic JZ SoCs.
+
 endmenu
index 2e7936e..4dfe422 100644 (file)
@@ -80,6 +80,7 @@ obj-$(CONFIG_ASM9260_TIMER)           += asm9260_timer.o
 obj-$(CONFIG_H8300_TMR8)               += h8300_timer8.o
 obj-$(CONFIG_H8300_TMR16)              += h8300_timer16.o
 obj-$(CONFIG_H8300_TPU)                        += h8300_tpu.o
+obj-$(CONFIG_INGENIC_TIMER)            += ingenic-timer.o
 obj-$(CONFIG_CLKSRC_ST_LPC)            += clksrc_st_lpc.o
 obj-$(CONFIG_X86_NUMACHIP)             += numachip.o
 obj-$(CONFIG_ATCPIT100_TIMER)          += timer-atcpit100.o
diff --git a/drivers/clocksource/ingenic-timer.c b/drivers/clocksource/ingenic-timer.c
new file mode 100644 (file)
index 0000000..4bbdb3d
--- /dev/null
@@ -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);