| Message ID | 1431158038-3813-5-git-send-email-mcoquelin.stm32@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Daniel, 2015-05-09 9:53 GMT+02:00 Maxime Coquelin <mcoquelin.stm32@gmail.com>: > This patch adds clocksource support for ARMv7-M's System timer, > also known as SysTick. > > Tested-by: Chanwoo Choi <cw00.choi@samsung.com> > Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> > Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> > --- > drivers/clocksource/Kconfig | 7 ++++ > drivers/clocksource/Makefile | 1 + > drivers/clocksource/armv7m_systick.c | 79 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 87 insertions(+) > create mode 100644 drivers/clocksource/armv7m_systick.c > Could you consider applying this patch and its dt-bindings documentation (patch 3/16) on your tree for v4.2? Thanks in advance, Maxime
On 05/18/2015 01:55 PM, Maxime Coquelin wrote: > Hi Daniel, > > 2015-05-09 9:53 GMT+02:00 Maxime Coquelin <mcoquelin.stm32@gmail.com>: >> This patch adds clocksource support for ARMv7-M's System timer, >> also known as SysTick. >> >> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> >> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >> --- >> drivers/clocksource/Kconfig | 7 ++++ >> drivers/clocksource/Makefile | 1 + >> drivers/clocksource/armv7m_systick.c | 79 ++++++++++++++++++++++++++++++++++++ >> 3 files changed, 87 insertions(+) >> create mode 100644 drivers/clocksource/armv7m_systick.c >> > > Could you consider applying this patch and its dt-bindings > documentation (patch 3/16) on your tree for v4.2? Patches applied for 4.2. Thanks -- Daniel
2015-05-18 14:49 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > On 05/18/2015 01:55 PM, Maxime Coquelin wrote: >> >> Hi Daniel, >> >> 2015-05-09 9:53 GMT+02:00 Maxime Coquelin <mcoquelin.stm32@gmail.com>: >>> >>> This patch adds clocksource support for ARMv7-M's System timer, >>> also known as SysTick. >>> >>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> >>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>> --- >>> drivers/clocksource/Kconfig | 7 ++++ >>> drivers/clocksource/Makefile | 1 + >>> drivers/clocksource/armv7m_systick.c | 79 >>> ++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 87 insertions(+) >>> create mode 100644 drivers/clocksource/armv7m_systick.c >>> >> >> Could you consider applying this patch and its dt-bindings >> documentation (patch 3/16) on your tree for v4.2? > > > Patches applied for 4.2. Thanks Daniel! > > Thanks > > -- Daniel > > -- > <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs > > Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | > <http://twitter.com/#!/linaroorg> Twitter | > <http://www.linaro.org/linaro-blog/> Blog >
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 51d7865f..bf9364c 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -139,6 +139,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK help Use ARM global timer clock source as sched_clock +config ARMV7M_SYSTICK + bool + select CLKSRC_OF if OF + select CLKSRC_MMIO + help + This options enables support for the ARMv7M system timer unit + config ATMEL_PIT select CLKSRC_OF if OF def_bool SOC_AT91SAM9 || SOC_SAMA5 diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 5b85f6a..d510c54 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -45,6 +45,7 @@ obj-$(CONFIG_MTK_TIMER) += mtk_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o obj-$(CONFIG_ARM_GLOBAL_TIMER) += arm_global_timer.o +obj-$(CONFIG_ARMV7M_SYSTICK) += armv7m_systick.o obj-$(CONFIG_CLKSRC_METAG_GENERIC) += metag_generic.o obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST) += dummy_timer.o obj-$(CONFIG_ARCH_KEYSTONE) += timer-keystone.o diff --git a/drivers/clocksource/armv7m_systick.c b/drivers/clocksource/armv7m_systick.c new file mode 100644 index 0000000..addfd2c --- /dev/null +++ b/drivers/clocksource/armv7m_systick.c @@ -0,0 +1,79 @@ +/* + * Copyright (C) Maxime Coquelin 2015 + * Author: Maxime Coquelin <mcoquelin.stm32@gmail.com> + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/kernel.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/clk.h> +#include <linux/bitops.h> + +#define SYST_CSR 0x00 +#define SYST_RVR 0x04 +#define SYST_CVR 0x08 +#define SYST_CALIB 0x0c + +#define SYST_CSR_ENABLE BIT(0) + +#define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF + +static void __init system_timer_of_register(struct device_node *np) +{ + struct clk *clk = NULL; + void __iomem *base; + u32 rate; + int ret; + + base = of_iomap(np, 0); + if (!base) { + pr_warn("system-timer: invalid base address\n"); + return; + } + + ret = of_property_read_u32(np, "clock-frequency", &rate); + if (ret) { + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) + goto out_unmap; + + ret = clk_prepare_enable(clk); + if (ret) + goto out_clk_put; + + rate = clk_get_rate(clk); + if (!rate) + goto out_clk_disable; + } + + writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR); + writel_relaxed(SYST_CSR_ENABLE, base + SYST_CSR); + + ret = clocksource_mmio_init(base + SYST_CVR, "arm_system_timer", rate, + 200, 24, clocksource_mmio_readl_down); + if (ret) { + pr_err("failed to init clocksource (%d)\n", ret); + if (clk) + goto out_clk_disable; + else + goto out_unmap; + } + + pr_info("ARM System timer initialized as clocksource\n"); + + return; + +out_clk_disable: + clk_disable_unprepare(clk); +out_clk_put: + clk_put(clk); +out_unmap: + iounmap(base); + pr_warn("ARM System timer register failed (%d)\n", ret); +} + +CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick", + system_timer_of_register);