From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Brandt Subject: [PATCH v2 2/2] clocksource: Add renesas-ostm timer driver Date: Fri, 20 Jan 2017 16:20:03 -0500 Message-ID: <20170120212003.4103-3-chris.brandt@renesas.com> References: <20170120212003.4103-1-chris.brandt@renesas.com> Return-path: In-Reply-To: <20170120212003.4103-1-chris.brandt@renesas.com> Sender: linux-renesas-soc-owner@vger.kernel.org To: Rob Herring , Mark Rutland , Simon Horman , Magnus Damm , Russell King , Daniel Lezcano , Thomas Gleixner , Geert Uytterhoeven Cc: devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Chris Brandt List-Id: devicetree@vger.kernel.org This patch adds a OSTM driver for the Renesas architecture. Signed-off-by: Chris Brandt --- v2: * changed implementation to be independent channel nodes --- arch/arm/mach-shmobile/Kconfig | 1 + drivers/clocksource/Kconfig | 12 ++ drivers/clocksource/Makefile | 1 + drivers/clocksource/renesas-ostm.c | 349 +++++++++++++++++++++++++++++++++++++ 4 files changed, 363 insertions(+) create mode 100644 drivers/clocksource/renesas-ostm.c diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig index 2bb4b09..b928634 100644 --- a/arch/arm/mach-shmobile/Kconfig +++ b/arch/arm/mach-shmobile/Kconfig @@ -57,6 +57,7 @@ config ARCH_R7S72100 select PM select PM_GENERIC_DOMAINS select SYS_SUPPORTS_SH_MTU2 + select SYS_SUPPORTS_RENESAS_OSTM config ARCH_R8A73A4 bool "R-Mobile APE6 (R8A73A40)" diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 4866f7a..95c8d56 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -431,6 +431,9 @@ config MTK_TIMER config SYS_SUPPORTS_SH_MTU2 bool +config SYS_SUPPORTS_RENESAS_OSTM + bool + config SYS_SUPPORTS_SH_TMU bool @@ -467,6 +470,15 @@ config SH_TIMER_MTU2 Timer Pulse Unit 2 (MTU2) hardware available on SoCs from Renesas. This hardware comes with 16 bit-timer registers. +config RENESAS_OSTM + bool "Renesas OSTM timer driver" if COMPILE_TEST + depends on GENERIC_CLOCKEVENTS + select CLKSRC_MMIO + default SYS_SUPPORTS_RENESAS_OSTM + help + This enables the build of the OSTM timer driver. + It creates a clock source and clock event device. + config SH_TIMER_TMU bool "Renesas TMU timer driver" if COMPILE_TEST depends on GENERIC_CLOCKEVENTS diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index a14111e..bbd163b 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o obj-$(CONFIG_CLKSRC_JCORE_PIT) += jcore-pit.o obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o +obj-$(CONFIG_RENESAS_OSTM) += renesas-ostm.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o obj-$(CONFIG_EM_TIMER_STI) += em_sti.o obj-$(CONFIG_CLKBLD_I8253) += i8253.o diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c new file mode 100644 index 0000000..37f2461 --- /dev/null +++ b/drivers/clocksource/renesas-ostm.c @@ -0,0 +1,349 @@ +/* + * Renesas Timer Support - OSTM + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +/* + * The OSTM contains independent channels. + * The first OSTM channel probed will be set up as a free running + * clocksource. Additionally we will use this clocksource for the system + * schedule timer sched_clock(). + * + * The second (or more) channel probed will be set up as an interrupt + * driven clock event. + */ + +struct ostm_device { + struct platform_device *pdev; + + int irq; + struct clk *clk; + unsigned long rate; + void __iomem *base; + unsigned long ticks_per_jiffy; + struct clock_event_device ced; +}; + +static void __iomem *system_clock; /* For sched_clock() */ + +/* OSTM REGISTERS */ +#define OSTM_CMP 0x000 /* RW,32 */ +#define OSTM_CNT 0x004 /* R,32 */ +#define OSTM_TE 0x010 /* R,8 */ +#define OSTM_TS 0x014 /* W,8 */ +#define OSTM_TT 0x018 /* W,8 */ +#define OSTM_CTL 0x020 /* RW,8 */ + +#define TE 0x01 +#define TS 0x01 +#define TT 0x01 +#define CTL_PERIODIC 0x00 +#define CTL_ONESHOT 0x02 +#define CTL_FREERUN 0x02 + +static struct ostm_device *ced_to_ostm(struct clock_event_device *ced) +{ + return container_of(ced, struct ostm_device, ced); +} + +static int __init ostm_init_clksrc(struct ostm_device *ostm) +{ + int ret; + + /* irq not used (clock sources don't use interrupts) */ + + /* stop counter */ + iowrite8(TT, ostm->base + OSTM_TT); + while (ioread8(ostm->base + OSTM_TE) & TE) + ; + + /* setup as freerun */ + iowrite32(0, ostm->base + OSTM_CMP); + iowrite8(CTL_FREERUN, ostm->base + OSTM_CTL); + iowrite8(TS, ostm->base + OSTM_TS); + + /* register */ + ret = clocksource_mmio_init(ostm->base + OSTM_CNT, + "ostm", ostm->rate, + 300, 32, clocksource_mmio_readl_up); + + return ret; +} + +static u64 notrace ostm_read_sched_clock(void) +{ + return ioread32(system_clock); +} + +static int __init ostm_init_sched_clock(struct ostm_device *ostm) +{ + unsigned long flags; + + system_clock = ostm->base + OSTM_CNT; + local_irq_save(flags); + local_irq_disable(); + sched_clock_register(ostm_read_sched_clock, 32, ostm->rate); + local_irq_restore(flags); + + return 0; +} + +static void ostm_clkevt_timer_stop(struct ostm_device *ostm) +{ + if (ioread8(ostm->base + OSTM_TE) & TE) { + iowrite8(TT, ostm->base + OSTM_TT); + while (ioread8(ostm->base + OSTM_TE) & TE) + ; + } +} + +static int ostm_clock_event_next(unsigned long delta, + struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + WARN_ON(!clockevent_state_oneshot(ced)); + + ostm_clkevt_timer_stop(ostm); + + iowrite32(delta, ostm->base + OSTM_CMP); + iowrite8(CTL_ONESHOT, ostm->base + OSTM_CTL); + iowrite8(TS, ostm->base + OSTM_TS); + + return 0; +} + +static int ostm_shutdown(struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + ostm_clkevt_timer_stop(ostm); + + return 0; +} +static int ostm_set_periodic(struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced)) + ostm_clkevt_timer_stop(ostm); + + iowrite32(ostm->ticks_per_jiffy - 1, ostm->base + OSTM_CMP); + iowrite8(CTL_PERIODIC, ostm->base + OSTM_CTL); + iowrite8(TS, ostm->base + OSTM_TS); + + return 0; +} + +static int ostm_set_oneshot(struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + ostm_clkevt_timer_stop(ostm); + + return 0; +} + +static irqreturn_t ostm_timer_interrupt(int irq, void *dev_id) +{ + struct ostm_device *ostm = dev_id; + + if (clockevent_state_oneshot(&ostm->ced)) + ostm_clkevt_timer_stop(ostm); + + /* notify clockevent layer */ + if (ostm->ced.event_handler) + ostm->ced.event_handler(&ostm->ced); + + return IRQ_HANDLED; +} + +static int __init ostm_init_clkevt(struct ostm_device *ostm) +{ + struct clock_event_device *ced = &ostm->ced; + int ret = -ENXIO; + + ret = request_irq(ostm->irq, ostm_timer_interrupt, + IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, + dev_name(&ostm->pdev->dev), ostm); + if (ret) { + dev_err(&ostm->pdev->dev, "failed to request irq\n"); + return ret; + } + + ced->name = "ostm"; + ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC; + ced->set_state_shutdown = ostm_shutdown; + ced->set_state_periodic = ostm_set_periodic; + ced->set_state_oneshot = ostm_set_oneshot; + ced->set_next_event = ostm_clock_event_next; + ced->shift = 32; + ced->rating = 300; + ced->cpumask = cpumask_of(0); + clockevents_config_and_register(ced, ostm->rate, 0xf, 0xffffffff); + + return 0; +} + +static int __init ostm_probe(struct platform_device *pdev) +{ + struct ostm_device *ostm; + struct resource *res; + int ret = -EFAULT; + + if (!is_early_platform_device(pdev)) { + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + } + + ostm = platform_get_drvdata(pdev); + if (ostm) { + dev_info(&pdev->dev, "kept as earlytimer\n"); + ret = 0; + goto out; + } + + ostm = kzalloc(sizeof(*ostm), GFP_KERNEL); + if (!ostm) { + dev_err(&pdev->dev, "failed to allocate memory\n"); + return -ENOMEM; + } + + ostm->pdev = pdev; + platform_set_drvdata(ostm->pdev, ostm); + + res = platform_get_resource(ostm->pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&ostm->pdev->dev, "failed to get I/O memory\n"); + goto err; + } + + ostm->base = ioremap_nocache(res->start, resource_size(res)); + if (!ostm->base) { + dev_err(&ostm->pdev->dev, "failed to remap I/O memory\n"); + goto err; + } + + ostm->irq = platform_get_irq(ostm->pdev, 0); + if (ostm->irq < 0) { + dev_err(&ostm->pdev->dev, "failed to get irq\n"); + goto err; + } + + ostm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(ostm->clk)) { + dev_err(&ostm->pdev->dev, "failed to get clock\n"); + ostm->clk = NULL; + goto err; + } + + ret = clk_prepare_enable(ostm->clk); + if (ret) { + dev_err(&ostm->pdev->dev, "failed to enable clock\n"); + goto err; + } + + ostm->rate = clk_get_rate(ostm->clk); + ostm->ticks_per_jiffy = (ostm->rate + HZ / 2) / HZ; + + /* First probed device will be used as system clocksource */ + if (!system_clock) { + /* use as clocksource */ + ret = ostm_init_clksrc(ostm); + + /* use as system scheduling clock */ + if (!ret) + ret = ostm_init_sched_clock(ostm); + + if (ret) { + dev_err(&pdev->dev, "failed to use as sched_clock\n"); + system_clock = (void *)-1; /* prevent future attempts */ + ret = 0; /* still works as clocksource */ + } + + if (!ret) + dev_info(&pdev->dev, "used for clocksource\n"); + } else { + /* use as clock event */ + ret = ostm_init_clkevt(ostm); + + if (!ret) + dev_info(&pdev->dev, "used for clock events\n"); + } + +err: + if (ret) { + if (ostm->clk) + clk_disable_unprepare(ostm->clk); + if (ostm->base) + iounmap(ostm->base); + kfree(ostm); + platform_set_drvdata(pdev, NULL); + pm_runtime_idle(&pdev->dev); + return ret; + } + + if (is_early_platform_device(pdev)) + return ret; + +out: + pm_runtime_irq_safe(&pdev->dev); + + return ret; +} + +static int ostm_remove(struct platform_device *pdev) +{ + return -EBUSY; /* cannot unregister clockevent */ +} + +static const struct of_device_id ostm_of_table[] __maybe_unused = { + { .compatible = "renesas,ostm" }, + { } +}; +MODULE_DEVICE_TABLE(of, ostm_of_table); + +static struct platform_driver ostm_timer = { + .probe = ostm_probe, + .remove = ostm_remove, + .driver = { + .name = "ostm", + .of_match_table = of_match_ptr(ostm_of_table), + }, +}; + +static int __init ostm_init(void) +{ + return platform_driver_register(&ostm_timer); +} + +static void __exit ostm_exit(void) +{ + platform_driver_unregister(&ostm_timer); +} + +early_platform_init("earlytimer", &ostm_timer); +subsys_initcall(ostm_init); +module_exit(ostm_exit); + +MODULE_AUTHOR("Chris Brandt"); +MODULE_DESCRIPTION("Renesas OSTM Timer Driver"); +MODULE_LICENSE("GPL v2"); -- 2.10.1