| Message ID | 1431158038-3813-10-git-send-email-mcoquelin.stm32@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Daniel, 2015-05-09 9:53 GMT+02:00 Maxime Coquelin <mcoquelin.stm32@gmail.com>: > STM32 MCUs feature 16 and 32 bits general purpose timers with prescalers. > The drivers detects whether the time is 16 or 32 bits, and applies a > 1024 prescaler value if it is 16 bits. > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > Tested-by: Chanwoo Choi <cw00.choi@samsung.com> > Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> > --- > drivers/clocksource/Kconfig | 8 ++ > drivers/clocksource/Makefile | 1 + > drivers/clocksource/timer-stm32.c | 184 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 193 insertions(+) > create mode 100644 drivers/clocksource/timer-stm32.c > I forgot to as you to also pick this one an its documentation (patch 8). Best regards, Maxime
On 05/09/2015 09:53 AM, Maxime Coquelin wrote: > STM32 MCUs feature 16 and 32 bits general purpose timers with prescalers. > The drivers detects whether the time is 16 or 32 bits, and applies a > 1024 prescaler value if it is 16 bits. > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > Tested-by: Chanwoo Choi <cw00.choi@samsung.com> > Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> > --- > drivers/clocksource/Kconfig | 8 ++ > drivers/clocksource/Makefile | 1 + > drivers/clocksource/timer-stm32.c | 184 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 193 insertions(+) > create mode 100644 drivers/clocksource/timer-stm32.c > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > index bf9364c..2443520 100644 > --- a/drivers/clocksource/Kconfig > +++ b/drivers/clocksource/Kconfig > @@ -106,6 +106,14 @@ config CLKSRC_EFM32 > Support to use the timers of EFM32 SoCs as clock source and clock > event device. > > +config CLKSRC_STM32 > + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 > + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) Are the interactive bool and the 'COMPILE_TEST' necessary ? > + select CLKSRC_MMIO > + default ARCH_STM32 > + help > + Support to use the timers of STM32 SoCs as clock event device. > + > config ARM_ARCH_TIMER > bool > select CLKSRC_OF if OF > diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile > index d510c54..888a7df 100644 > --- a/drivers/clocksource/Makefile > +++ b/drivers/clocksource/Makefile > @@ -36,6 +36,7 @@ obj-$(CONFIG_ARCH_NSPIRE) += zevio-timer.o > obj-$(CONFIG_ARCH_BCM_MOBILE) += bcm_kona_timer.o > obj-$(CONFIG_CADENCE_TTC_TIMER) += cadence_ttc_timer.o > obj-$(CONFIG_CLKSRC_EFM32) += time-efm32.o > +obj-$(CONFIG_CLKSRC_STM32) += timer-stm32.o > obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o > obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o > obj-$(CONFIG_FSL_FTM_TIMER) += fsl_ftm_timer.o > diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c > new file mode 100644 > index 0000000..fad2e2e > --- /dev/null > +++ b/drivers/clocksource/timer-stm32.c > @@ -0,0 +1,184 @@ > +/* > + * Copyright (C) Maxime Coquelin 2015 > + * Author: Maxime Coquelin <mcoquelin.stm32@gmail.com> > + * License terms: GNU General Public License (GPL), version 2 > + * > + * Inspired by time-efm32.c from Uwe Kleine-Koenig > + */ > + > +#include <linux/kernel.h> > +#include <linux/clocksource.h> > +#include <linux/clockchips.h> > +#include <linux/irq.h> > +#include <linux/interrupt.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/of_irq.h> > +#include <linux/clk.h> > +#include <linux/reset.h> > + > +#define TIM_CR1 0x00 > +#define TIM_DIER 0x0c > +#define TIM_SR 0x10 > +#define TIM_EGR 0x14 > +#define TIM_PSC 0x28 > +#define TIM_ARR 0x2c > + > +#define TIM_CR1_CEN BIT(0) > +#define TIM_CR1_OPM BIT(3) > +#define TIM_CR1_ARPE BIT(7) > + > +#define TIM_DIER_UIE BIT(0) > + > +#define TIM_SR_UIF BIT(0) > + > +#define TIM_EGR_UG BIT(0) > + > +struct stm32_clock_event_ddata { > + struct clock_event_device evtdev; > + unsigned periodic_top; > + void __iomem *base; > +}; > + > +static void stm32_clock_event_set_mode(enum clock_event_mode mode, > + struct clock_event_device *evtdev) > +{ > + struct stm32_clock_event_ddata *data = > + container_of(evtdev, struct stm32_clock_event_ddata, evtdev); > + void *base = data->base; > + > + switch (mode) { > + case CLOCK_EVT_MODE_PERIODIC: > + writel_relaxed(data->periodic_top, base + TIM_ARR); > + writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, base + TIM_CR1); > + break; > + > + case CLOCK_EVT_MODE_ONESHOT: > + default: > + writel_relaxed(0, base + TIM_CR1); > + break; > + } > +} > + > +static int stm32_clock_event_set_next_event(unsigned long evt, > + struct clock_event_device *evtdev) > +{ > + struct stm32_clock_event_ddata *data = > + container_of(evtdev, struct stm32_clock_event_ddata, evtdev); > + > + writel_relaxed(evt, data->base + TIM_ARR); > + writel_relaxed(TIM_CR1_ARPE | TIM_CR1_OPM | TIM_CR1_CEN, > + data->base + TIM_CR1); > + > + return 0; > +} > + > +static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id) > +{ > + struct stm32_clock_event_ddata *data = dev_id; > + > + writel_relaxed(0, data->base + TIM_SR); > + > + data->evtdev.event_handler(&data->evtdev); > + > + return IRQ_HANDLED; > +} > + > +static struct stm32_clock_event_ddata clock_event_ddata = { > + .evtdev = { > + .name = "stm32 clockevent", > + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, > + .set_mode = stm32_clock_event_set_mode, > + .set_next_event = stm32_clock_event_set_next_event, > + .rating = 200, > + }, > +}; > + > +static void __init stm32_clockevent_init(struct device_node *np) > +{ > + struct stm32_clock_event_ddata *data = &clock_event_ddata; > + struct clk *clk; > + struct reset_control *rstc; > + unsigned long rate, max_delta; > + int irq, ret, bits, prescaler = 1; > + > + clk = of_clk_get(np, 0); > + if (IS_ERR(clk)) { > + ret = PTR_ERR(clk); > + pr_err("failed to get clock for clockevent (%d)\n", ret); > + goto err_clk_get; > + } > + > + ret = clk_prepare_enable(clk); > + if (ret) { > + pr_err("failed to enable timer clock for clockevent (%d)\n", > + ret); > + goto err_clk_enable; > + } > + > + rate = clk_get_rate(clk); > + > + rstc = of_reset_control_get(np, NULL); > + if (!IS_ERR(rstc)) { > + reset_control_assert(rstc); > + reset_control_deassert(rstc); > + } > + > + data->base = of_iomap(np, 0); > + if (!data->base) { > + pr_err("failed to map registers for clockevent\n"); > + goto err_iomap; > + } > + > + irq = irq_of_parse_and_map(np, 0); > + if (!irq) { > + pr_err("%s: failed to get irq.\n", np->full_name); > + goto err_get_irq; > + } > + > + /* Detect whether the timer is 16 or 32 bits */ > + writel_relaxed(~0UL, data->base + TIM_ARR); > + max_delta = readl_relaxed(data->base + TIM_ARR); > + if (max_delta == ~0UL) { > + prescaler = 1; > + bits = 32; > + } else { > + prescaler = 1024; > + bits = 16; > + } > + writel_relaxed(0, data->base + TIM_ARR); > + > + writel_relaxed(prescaler - 1, data->base + TIM_PSC); > + writel_relaxed(TIM_EGR_UG, data->base + TIM_EGR); > + writel_relaxed(TIM_DIER_UIE, data->base + TIM_DIER); > + writel_relaxed(0, data->base + TIM_SR); > + > + data->periodic_top = DIV_ROUND_CLOSEST(rate, prescaler * HZ); > + > + clockevents_config_and_register(&data->evtdev, > + DIV_ROUND_CLOSEST(rate, prescaler), > + 0x1, max_delta); > + > + ret = request_irq(irq, stm32_clock_event_handler, IRQF_TIMER, > + "stm32 clockevent", data); > + if (ret) { > + pr_err("%s: failed to request irq.\n", np->full_name); > + goto err_get_irq; > + } > + > + pr_info("%s: STM32 clockevent driver initialized (%d bits)\n", > + np->full_name, bits); > + > + return; > + > +err_get_irq: > + iounmap(data->base); > +err_iomap: > + clk_disable_unprepare(clk); > +err_clk_enable: > + clk_put(clk); > +err_clk_get: > + return; > +} > + > +CLOCKSOURCE_OF_DECLARE(stm32, "st,stm32-timer", stm32_clockevent_init); >
2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >> >> STM32 MCUs feature 16 and 32 bits general purpose timers with prescalers. >> The drivers detects whether the time is 16 or 32 bits, and applies a >> 1024 prescaler value if it is 16 bits. >> >> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >> --- >> drivers/clocksource/Kconfig | 8 ++ >> drivers/clocksource/Makefile | 1 + >> drivers/clocksource/timer-stm32.c | 184 >> ++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 193 insertions(+) >> create mode 100644 drivers/clocksource/timer-stm32.c >> >> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >> index bf9364c..2443520 100644 >> --- a/drivers/clocksource/Kconfig >> +++ b/drivers/clocksource/Kconfig >> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >> Support to use the timers of EFM32 SoCs as clock source and >> clock >> event device. >> >> +config CLKSRC_STM32 >> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) > > > Are the interactive bool and the 'COMPILE_TEST' necessary ? > The interactive bool is necessary if we want to be able to select/deselect it in COMPILE_TEST configuration. And personnaly, I think COMPILE_TEST use makes sense. Note that other timer drivers are doing the same thing today (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). Do you have a specific concern regarding COMPILE_TEST? Kind regards, Maxime
On 05/18/2015 04:03 PM, Maxime Coquelin wrote: > 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >> On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >>> >>> STM32 MCUs feature 16 and 32 bits general purpose timers with prescalers. >>> The drivers detects whether the time is 16 or 32 bits, and applies a >>> 1024 prescaler value if it is 16 bits. >>> >>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>> --- >>> drivers/clocksource/Kconfig | 8 ++ >>> drivers/clocksource/Makefile | 1 + >>> drivers/clocksource/timer-stm32.c | 184 >>> ++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 193 insertions(+) >>> create mode 100644 drivers/clocksource/timer-stm32.c >>> >>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >>> index bf9364c..2443520 100644 >>> --- a/drivers/clocksource/Kconfig >>> +++ b/drivers/clocksource/Kconfig >>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >>> Support to use the timers of EFM32 SoCs as clock source and >>> clock >>> event device. >>> >>> +config CLKSRC_STM32 >>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) >> >> >> Are the interactive bool and the 'COMPILE_TEST' necessary ? >> > > The interactive bool is necessary if we want to be able to > select/deselect it in COMPILE_TEST configuration. > And personnaly, I think COMPILE_TEST use makes sense. > > Note that other timer drivers are doing the same thing today > (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). > > Do you have a specific concern regarding COMPILE_TEST? Actually, we try to keep the timer selection non-interactive and let the platform's Kconfig to select the timer. I like when the code is consistent. The COMPILE_TEST was introduced and created a precedence. I would like to get rid of the interactive timer selection but I did not have time to go through this yet.
2015-05-19 10:16 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > On 05/18/2015 04:03 PM, Maxime Coquelin wrote: >> >> 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>> >>> On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >>>> >>>> >>>> STM32 MCUs feature 16 and 32 bits general purpose timers with >>>> prescalers. >>>> The drivers detects whether the time is 16 or 32 bits, and applies a >>>> 1024 prescaler value if it is 16 bits. >>>> >>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >>>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>>> --- >>>> drivers/clocksource/Kconfig | 8 ++ >>>> drivers/clocksource/Makefile | 1 + >>>> drivers/clocksource/timer-stm32.c | 184 >>>> ++++++++++++++++++++++++++++++++++++++ >>>> 3 files changed, 193 insertions(+) >>>> create mode 100644 drivers/clocksource/timer-stm32.c >>>> >>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >>>> index bf9364c..2443520 100644 >>>> --- a/drivers/clocksource/Kconfig >>>> +++ b/drivers/clocksource/Kconfig >>>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >>>> Support to use the timers of EFM32 SoCs as clock source and >>>> clock >>>> event device. >>>> >>>> +config CLKSRC_STM32 >>>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >>>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) >>> >>> >>> >>> Are the interactive bool and the 'COMPILE_TEST' necessary ? >>> >> >> The interactive bool is necessary if we want to be able to >> select/deselect it in COMPILE_TEST configuration. >> And personnaly, I think COMPILE_TEST use makes sense. >> >> Note that other timer drivers are doing the same thing today >> (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). >> >> Do you have a specific concern regarding COMPILE_TEST? > > > Actually, we try to keep the timer selection non-interactive and let the > platform's Kconfig to select the timer. Ok. > > I like when the code is consistent. The COMPILE_TEST was introduced and > created a precedence. I would like to get rid of the interactive timer > selection but I did not have time to go through this yet. Indeed, consistency is important. On my side, I don't have a strong opinion regarding the COMPILE_TEST thing. IMHO, it is more a subsystem's maintainer choice. So, if as a maintainer you don't use it and prefer not supporting it, I'm fine to provide you a new version without COMPILE_TEST. Doing that, the interactive selection will disappear too. I can provide you a new version this evenning. Best regards, Maxime > > > > -- > <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 >
On 05/19/2015 10:55 AM, Maxime Coquelin wrote: > 2015-05-19 10:16 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >> On 05/18/2015 04:03 PM, Maxime Coquelin wrote: >>> >>> 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>>> >>>> On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >>>>> >>>>> >>>>> STM32 MCUs feature 16 and 32 bits general purpose timers with >>>>> prescalers. >>>>> The drivers detects whether the time is 16 or 32 bits, and applies a >>>>> 1024 prescaler value if it is 16 bits. >>>>> >>>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >>>>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>>>> --- >>>>> drivers/clocksource/Kconfig | 8 ++ >>>>> drivers/clocksource/Makefile | 1 + >>>>> drivers/clocksource/timer-stm32.c | 184 >>>>> ++++++++++++++++++++++++++++++++++++++ >>>>> 3 files changed, 193 insertions(+) >>>>> create mode 100644 drivers/clocksource/timer-stm32.c >>>>> >>>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >>>>> index bf9364c..2443520 100644 >>>>> --- a/drivers/clocksource/Kconfig >>>>> +++ b/drivers/clocksource/Kconfig >>>>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >>>>> Support to use the timers of EFM32 SoCs as clock source and >>>>> clock >>>>> event device. >>>>> >>>>> +config CLKSRC_STM32 >>>>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >>>>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) >>>> >>>> >>>> >>>> Are the interactive bool and the 'COMPILE_TEST' necessary ? >>>> >>> >>> The interactive bool is necessary if we want to be able to >>> select/deselect it in COMPILE_TEST configuration. >>> And personnaly, I think COMPILE_TEST use makes sense. >>> >>> Note that other timer drivers are doing the same thing today >>> (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). >>> >>> Do you have a specific concern regarding COMPILE_TEST? >> >> >> Actually, we try to keep the timer selection non-interactive and let the >> platform's Kconfig to select the timer. > > Ok. > >> >> I like when the code is consistent. The COMPILE_TEST was introduced and >> created a precedence. I would like to get rid of the interactive timer >> selection but I did not have time to go through this yet. > > Indeed, consistency is important. > On my side, I don't have a strong opinion regarding the COMPILE_TEST thing. > IMHO, it is more a subsystem's maintainer choice. > > So, if as a maintainer you don't use it and prefer not supporting it, > I'm fine to provide you a new version without COMPILE_TEST. > Doing that, the interactive selection will disappear too. > > I can provide you a new version this evenning. Ok, great. 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 >>
2015-05-19 11:06 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > On 05/19/2015 10:55 AM, Maxime Coquelin wrote: >> >> 2015-05-19 10:16 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>> >>> On 05/18/2015 04:03 PM, Maxime Coquelin wrote: >>>> >>>> >>>> 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>>>> >>>>> >>>>> On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >>>>>> >>>>>> >>>>>> >>>>>> STM32 MCUs feature 16 and 32 bits general purpose timers with >>>>>> prescalers. >>>>>> The drivers detects whether the time is 16 or 32 bits, and applies a >>>>>> 1024 prescaler value if it is 16 bits. >>>>>> >>>>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >>>>>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>>>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>>>>> --- >>>>>> drivers/clocksource/Kconfig | 8 ++ >>>>>> drivers/clocksource/Makefile | 1 + >>>>>> drivers/clocksource/timer-stm32.c | 184 >>>>>> ++++++++++++++++++++++++++++++++++++++ >>>>>> 3 files changed, 193 insertions(+) >>>>>> create mode 100644 drivers/clocksource/timer-stm32.c >>>>>> >>>>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >>>>>> index bf9364c..2443520 100644 >>>>>> --- a/drivers/clocksource/Kconfig >>>>>> +++ b/drivers/clocksource/Kconfig >>>>>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >>>>>> Support to use the timers of EFM32 SoCs as clock source >>>>>> and >>>>>> clock >>>>>> event device. >>>>>> >>>>>> +config CLKSRC_STM32 >>>>>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >>>>>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) >>>>> >>>>> >>>>> >>>>> >>>>> Are the interactive bool and the 'COMPILE_TEST' necessary ? >>>>> >>>> >>>> The interactive bool is necessary if we want to be able to >>>> select/deselect it in COMPILE_TEST configuration. >>>> And personnaly, I think COMPILE_TEST use makes sense. >>>> >>>> Note that other timer drivers are doing the same thing today >>>> (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). >>>> >>>> Do you have a specific concern regarding COMPILE_TEST? >>> >>> >>> >>> Actually, we try to keep the timer selection non-interactive and let the >>> platform's Kconfig to select the timer. >> >> >> Ok. >> >>> >>> I like when the code is consistent. The COMPILE_TEST was introduced and >>> created a precedence. I would like to get rid of the interactive timer >>> selection but I did not have time to go through this yet. >> >> >> Indeed, consistency is important. >> On my side, I don't have a strong opinion regarding the COMPILE_TEST >> thing. >> IMHO, it is more a subsystem's maintainer choice. >> >> So, if as a maintainer you don't use it and prefer not supporting it, >> I'm fine to provide you a new version without COMPILE_TEST. >> Doing that, the interactive selection will disappear too. >> >> I can provide you a new version this evenning. > > > Ok, great. Is the below Kconfig entry fine for you? config CLKSRC_STM32 def_bool y if ARCH_STM32 select CLKSRC_MMIO Best regards, Maxime > > 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 >>> > > > -- > <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 >
On 05/19/2015 11:44 AM, Maxime Coquelin wrote: > 2015-05-19 11:06 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >> On 05/19/2015 10:55 AM, Maxime Coquelin wrote: >>> >>> 2015-05-19 10:16 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>>> >>>> On 05/18/2015 04:03 PM, Maxime Coquelin wrote: >>>>> >>>>> >>>>> 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>>>>> >>>>>> >>>>>> On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> STM32 MCUs feature 16 and 32 bits general purpose timers with >>>>>>> prescalers. >>>>>>> The drivers detects whether the time is 16 or 32 bits, and applies a >>>>>>> 1024 prescaler value if it is 16 bits. >>>>>>> >>>>>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >>>>>>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>>>>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>>>>>> --- >>>>>>> drivers/clocksource/Kconfig | 8 ++ >>>>>>> drivers/clocksource/Makefile | 1 + >>>>>>> drivers/clocksource/timer-stm32.c | 184 >>>>>>> ++++++++++++++++++++++++++++++++++++++ >>>>>>> 3 files changed, 193 insertions(+) >>>>>>> create mode 100644 drivers/clocksource/timer-stm32.c >>>>>>> >>>>>>> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig >>>>>>> index bf9364c..2443520 100644 >>>>>>> --- a/drivers/clocksource/Kconfig >>>>>>> +++ b/drivers/clocksource/Kconfig >>>>>>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >>>>>>> Support to use the timers of EFM32 SoCs as clock source >>>>>>> and >>>>>>> clock >>>>>>> event device. >>>>>>> >>>>>>> +config CLKSRC_STM32 >>>>>>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >>>>>>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Are the interactive bool and the 'COMPILE_TEST' necessary ? >>>>>> >>>>> >>>>> The interactive bool is necessary if we want to be able to >>>>> select/deselect it in COMPILE_TEST configuration. >>>>> And personnaly, I think COMPILE_TEST use makes sense. >>>>> >>>>> Note that other timer drivers are doing the same thing today >>>>> (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). >>>>> >>>>> Do you have a specific concern regarding COMPILE_TEST? >>>> >>>> >>>> >>>> Actually, we try to keep the timer selection non-interactive and let the >>>> platform's Kconfig to select the timer. >>> >>> >>> Ok. >>> >>>> >>>> I like when the code is consistent. The COMPILE_TEST was introduced and >>>> created a precedence. I would like to get rid of the interactive timer >>>> selection but I did not have time to go through this yet. >>> >>> >>> Indeed, consistency is important. >>> On my side, I don't have a strong opinion regarding the COMPILE_TEST >>> thing. >>> IMHO, it is more a subsystem's maintainer choice. >>> >>> So, if as a maintainer you don't use it and prefer not supporting it, >>> I'm fine to provide you a new version without COMPILE_TEST. >>> Doing that, the interactive selection will disappear too. >>> >>> I can provide you a new version this evenning. >> >> >> Ok, great. > > Is the below Kconfig entry fine for you? > > config CLKSRC_STM32 > def_bool y if ARCH_STM32 > select CLKSRC_MMIO config CLKSRC_STM32 bool select CLKSRC_MMIO and in the arch/arm/mach-stm32/Kconfig add select CLKSRC_STM32 > Best regards, > Maxime > > >> >> 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 >>>> >> >> >> -- >> <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 >>
2015-05-19 11:59 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > On 05/19/2015 11:44 AM, Maxime Coquelin wrote: >> >> 2015-05-19 11:06 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>> >>> On 05/19/2015 10:55 AM, Maxime Coquelin wrote: >>>> >>>> >>>> 2015-05-19 10:16 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>>>> >>>>> >>>>> On 05/18/2015 04:03 PM, Maxime Coquelin wrote: >>>>>> >>>>>> >>>>>> >>>>>> 2015-05-18 15:10 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 05/09/2015 09:53 AM, Maxime Coquelin wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> STM32 MCUs feature 16 and 32 bits general purpose timers with >>>>>>>> prescalers. >>>>>>>> The drivers detects whether the time is 16 or 32 bits, and applies a >>>>>>>> 1024 prescaler value if it is 16 bits. >>>>>>>> >>>>>>>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> >>>>>>>> Tested-by: Chanwoo Choi <cw00.choi@samsung.com> >>>>>>>> Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com> >>>>>>>> --- >>>>>>>> drivers/clocksource/Kconfig | 8 ++ >>>>>>>> drivers/clocksource/Makefile | 1 + >>>>>>>> drivers/clocksource/timer-stm32.c | 184 >>>>>>>> ++++++++++++++++++++++++++++++++++++++ >>>>>>>> 3 files changed, 193 insertions(+) >>>>>>>> create mode 100644 drivers/clocksource/timer-stm32.c >>>>>>>> >>>>>>>> diff --git a/drivers/clocksource/Kconfig >>>>>>>> b/drivers/clocksource/Kconfig >>>>>>>> index bf9364c..2443520 100644 >>>>>>>> --- a/drivers/clocksource/Kconfig >>>>>>>> +++ b/drivers/clocksource/Kconfig >>>>>>>> @@ -106,6 +106,14 @@ config CLKSRC_EFM32 >>>>>>>> Support to use the timers of EFM32 SoCs as clock source >>>>>>>> and >>>>>>>> clock >>>>>>>> event device. >>>>>>>> >>>>>>>> +config CLKSRC_STM32 >>>>>>>> + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 >>>>>>>> + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Are the interactive bool and the 'COMPILE_TEST' necessary ? >>>>>>> >>>>>> >>>>>> The interactive bool is necessary if we want to be able to >>>>>> select/deselect it in COMPILE_TEST configuration. >>>>>> And personnaly, I think COMPILE_TEST use makes sense. >>>>>> >>>>>> Note that other timer drivers are doing the same thing today >>>>>> (CLKSRC_EFM32, SH_TIMER_CMT, EM_TIMER_STI...). >>>>>> >>>>>> Do you have a specific concern regarding COMPILE_TEST? >>>>> >>>>> >>>>> >>>>> >>>>> Actually, we try to keep the timer selection non-interactive and let >>>>> the >>>>> platform's Kconfig to select the timer. >>>> >>>> >>>> >>>> Ok. >>>> >>>>> >>>>> I like when the code is consistent. The COMPILE_TEST was introduced and >>>>> created a precedence. I would like to get rid of the interactive timer >>>>> selection but I did not have time to go through this yet. >>>> >>>> >>>> >>>> Indeed, consistency is important. >>>> On my side, I don't have a strong opinion regarding the COMPILE_TEST >>>> thing. >>>> IMHO, it is more a subsystem's maintainer choice. >>>> >>>> So, if as a maintainer you don't use it and prefer not supporting it, >>>> I'm fine to provide you a new version without COMPILE_TEST. >>>> Doing that, the interactive selection will disappear too. >>>> >>>> I can provide you a new version this evenning. >>> >>> >>> >>> Ok, great. >> >> >> Is the below Kconfig entry fine for you? >> >> config CLKSRC_STM32 >> def_bool y if ARCH_STM32 >> select CLKSRC_MMIO > > > config CLKSRC_STM32 > bool > select CLKSRC_MMIO > > and in the arch/arm/mach-stm32/Kconfig add select CLKSRC_STM32 Ok, I will send a patch for arch/arm/Kconfig, as Arnd already applied the one intruducing ARCH_STM32. Thanks, Maxime > > >> Best regards, >> Maxime >> >> >>> >>> 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 >>>>> >>> >>> >>> -- >>> <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 >>> > > > -- > <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 >
On Tuesday 19 May 2015 12:02:59 Maxime Coquelin wrote: > > > > config CLKSRC_STM32 > > bool > > select CLKSRC_MMIO > > > > and in the arch/arm/mach-stm32/Kconfig add select CLKSRC_STM32 > > Ok, I will send a patch for arch/arm/Kconfig, as Arnd already applied > the one intruducing ARCH_STM32. > > Please also make it possible to select this driver on other architectures with COMPILE_TEST, so we get coverage from all the x86 test infrastructure. Arnd
On Tue, 19 May 2015, Maxime Coquelin wrote: > 2015-05-19 11:59 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > >> Is the below Kconfig entry fine for you? > >> > >> config CLKSRC_STM32 > >> def_bool y if ARCH_STM32 > >> select CLKSRC_MMIO > > > > > > config CLKSRC_STM32 > > bool > > select CLKSRC_MMIO > > > > and in the arch/arm/mach-stm32/Kconfig add select CLKSRC_STM32 > > Ok, I will send a patch for arch/arm/Kconfig, as Arnd already applied > the one intruducing ARCH_STM32. Folks, can you please trim your replies. It's a PITA to scroll down through several pages to find a single line of content. Thanks, tglx
On Tue, May 19, 2015 at 02:56:43PM +0200, Thomas Gleixner wrote: > On Tue, 19 May 2015, Maxime Coquelin wrote: > > 2015-05-19 11:59 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > > >> Is the below Kconfig entry fine for you? > > >> > > >> config CLKSRC_STM32 > > >> def_bool y if ARCH_STM32 > > >> select CLKSRC_MMIO > > > > > > > > > config CLKSRC_STM32 > > > bool > > > select CLKSRC_MMIO > > > > > > and in the arch/arm/mach-stm32/Kconfig add select CLKSRC_STM32 > > > > Ok, I will send a patch for arch/arm/Kconfig, as Arnd already applied > > the one intruducing ARCH_STM32. > > Folks, can you please trim your replies. It's a PITA to scroll down > through several pages to find a single line of content. Absolutely right. Too many people do not do this, and it's a waste of readers time. Maybe we should start ignoring emails which contain only quoted mail in the first 50 lines. Also, cutting the rest of the email below the point which you've finished replying is good etiquette as well. I've seen a number of posts where people have added their signature mid-mail and left a huge chunk of quoted mail below. That's just not on either.
2015-05-19 15:00 GMT+02:00 Russell King - ARM Linux <linux@arm.linux.org.uk>: > On Tue, May 19, 2015 at 02:56:43PM +0200, Thomas Gleixner wrote: >> Folks, can you please trim your replies. It's a PITA to scroll down >> through several pages to find a single line of content. > > Absolutely right. Too many people do not do this, and it's a waste of > readers time. Maybe we should start ignoring emails which contain only > quoted mail in the first 50 lines. > > Also, cutting the rest of the email below the point which you've finished > replying is good etiquette as well. I've seen a number of posts where > people have added their signature mid-mail and left a huge chunk of quoted > mail below. That's just not on either. > Ok, I will take care of that. Sorry for the inconvenience, Maxime
2015-05-19 12:55 GMT+02:00 Arnd Bergmann <arnd@arndb.de>: > Please also make it possible to select this driver on other architectures > with COMPILE_TEST, so we get coverage from all the x86 test infrastructure. You proposal is to revert back to the original patch, except that ARCH_STM32 should select CLKSRC_STM32, right? Daniel, what do you think? Regards, Maxime
On 05/19/2015 03:42 PM, Maxime Coquelin wrote: > 2015-05-19 12:55 GMT+02:00 Arnd Bergmann <arnd@arndb.de>: >> Please also make it possible to select this driver on other architectures >> with COMPILE_TEST, so we get coverage from all the x86 test infrastructure. > > You proposal is to revert back to the original patch, except that > ARCH_STM32 should select CLKSRC_STM32, right? > > Daniel, what do you think? It is not exactly as the initial patch. I think Arnd is proposing: config CLKSRC_STM32 bool "Clocksource for STM32 SoCs" if COMPILE_TEST select CLKSRC_MMIO
On Tuesday 19 May 2015 15:49:52 Daniel Lezcano wrote: > On 05/19/2015 03:42 PM, Maxime Coquelin wrote: > > 2015-05-19 12:55 GMT+02:00 Arnd Bergmann <arnd@arndb.de>: > >> Please also make it possible to select this driver on other architectures > >> with COMPILE_TEST, so we get coverage from all the x86 test infrastructure. > > > > You proposal is to revert back to the original patch, except that > > ARCH_STM32 should select CLKSRC_STM32, right? > > > > Daniel, what do you think? > > It is not exactly as the initial patch. > > I think Arnd is proposing: > > config CLKSRC_STM32 > bool "Clocksource for STM32 SoCs" if COMPILE_TEST > select CLKSRC_MMIO Yes, that's fine, although we might also need a 'depends on OF' line, not sure. Arnd
2015-05-19 15:49 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > > > It is not exactly as the initial patch. > > I think Arnd is proposing: > > config CLKSRC_STM32 > bool "Clocksource for STM32 SoCs" if COMPILE_TEST > select CLKSRC_MMIO > Isn't "depends on OF" missing for COMPILE_TEST case? Other than that, I'm fine with the proposal. Daniel, is it the case for you too? Regards, Maxime
On Tue, May 19, 2015 at 04:41:58PM +0200, Maxime Coquelin wrote: > 2015-05-19 15:49 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: > > > > > > It is not exactly as the initial patch. > > > > I think Arnd is proposing: > > > > config CLKSRC_STM32 > > bool "Clocksource for STM32 SoCs" if COMPILE_TEST > > select CLKSRC_MMIO > > > > Isn't "depends on OF" missing for COMPILE_TEST case? config CLKSRC_STM32 bool "Clocksource for STM32 SoCs" if COMPILE_TEST depends on OF select CLKSRC_MMIO This permits CLKSRC_STM32 to be selected by STM32 (provided OF is enabled, it's always going to be for that case, right?) while allowing the option to be visible when both OF!=n and COMPILE_TEST!=n. Remember, bool "string" if <condition-affects-visibility-of-string> depends on <condition-affects-config-symbol-availability> The former merely hides the option from the user _if_ the condition fails. The latter _disables_ the option completely (except if you try and select it, at which point you end up with a Kconfig warning about that.)
On 05/19/2015 04:41 PM, Maxime Coquelin wrote: > 2015-05-19 15:49 GMT+02:00 Daniel Lezcano <daniel.lezcano@linaro.org>: >> >> >> It is not exactly as the initial patch. >> >> I think Arnd is proposing: >> >> config CLKSRC_STM32 >> bool "Clocksource for STM32 SoCs" if COMPILE_TEST >> select CLKSRC_MMIO >> > > Isn't "depends on OF" missing for COMPILE_TEST case? Hmm, yes. Probably. > Other than that, I'm fine with the proposal. > Daniel, is it the case for you too? Yep.
2015-05-19 16:50 GMT+02:00 Russell King - ARM Linux <linux@arm.linux.org.uk>: > > config CLKSRC_STM32 > bool "Clocksource for STM32 SoCs" if COMPILE_TEST > depends on OF > select CLKSRC_MMIO > > This permits CLKSRC_STM32 to be selected by STM32 (provided OF is enabled, > it's always going to be for that case, right?) while allowing the option > to be visible when both OF!=n and COMPILE_TEST!=n. Yes OF is always enabled when STM32. So it fits our needs, as we only want the option to be visible when both OF!=n and COMPILE_TEST!=n. > > Remember, > > bool "string" if <condition-affects-visibility-of-string> > depends on <condition-affects-config-symbol-availability> > > The former merely hides the option from the user _if_ the condition fails. > The latter _disables_ the option completely (except if you try and select > it, at which point you end up with a Kconfig warning about that.) Thanks for the reminder! Maxime
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index bf9364c..2443520 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -106,6 +106,14 @@ config CLKSRC_EFM32 Support to use the timers of EFM32 SoCs as clock source and clock event device. +config CLKSRC_STM32 + bool "Clocksource for STM32 SoCs" if !ARCH_STM32 + depends on OF && ARM && (ARCH_STM32 || COMPILE_TEST) + select CLKSRC_MMIO + default ARCH_STM32 + help + Support to use the timers of STM32 SoCs as clock event device. + config ARM_ARCH_TIMER bool select CLKSRC_OF if OF diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index d510c54..888a7df 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_ARCH_NSPIRE) += zevio-timer.o obj-$(CONFIG_ARCH_BCM_MOBILE) += bcm_kona_timer.o obj-$(CONFIG_CADENCE_TTC_TIMER) += cadence_ttc_timer.o obj-$(CONFIG_CLKSRC_EFM32) += time-efm32.o +obj-$(CONFIG_CLKSRC_STM32) += timer-stm32.o obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o obj-$(CONFIG_CLKSRC_SAMSUNG_PWM) += samsung_pwm_timer.o obj-$(CONFIG_FSL_FTM_TIMER) += fsl_ftm_timer.o diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c new file mode 100644 index 0000000..fad2e2e --- /dev/null +++ b/drivers/clocksource/timer-stm32.c @@ -0,0 +1,184 @@ +/* + * Copyright (C) Maxime Coquelin 2015 + * Author: Maxime Coquelin <mcoquelin.stm32@gmail.com> + * License terms: GNU General Public License (GPL), version 2 + * + * Inspired by time-efm32.c from Uwe Kleine-Koenig + */ + +#include <linux/kernel.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/clk.h> +#include <linux/reset.h> + +#define TIM_CR1 0x00 +#define TIM_DIER 0x0c +#define TIM_SR 0x10 +#define TIM_EGR 0x14 +#define TIM_PSC 0x28 +#define TIM_ARR 0x2c + +#define TIM_CR1_CEN BIT(0) +#define TIM_CR1_OPM BIT(3) +#define TIM_CR1_ARPE BIT(7) + +#define TIM_DIER_UIE BIT(0) + +#define TIM_SR_UIF BIT(0) + +#define TIM_EGR_UG BIT(0) + +struct stm32_clock_event_ddata { + struct clock_event_device evtdev; + unsigned periodic_top; + void __iomem *base; +}; + +static void stm32_clock_event_set_mode(enum clock_event_mode mode, + struct clock_event_device *evtdev) +{ + struct stm32_clock_event_ddata *data = + container_of(evtdev, struct stm32_clock_event_ddata, evtdev); + void *base = data->base; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + writel_relaxed(data->periodic_top, base + TIM_ARR); + writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, base + TIM_CR1); + break; + + case CLOCK_EVT_MODE_ONESHOT: + default: + writel_relaxed(0, base + TIM_CR1); + break; + } +} + +static int stm32_clock_event_set_next_event(unsigned long evt, + struct clock_event_device *evtdev) +{ + struct stm32_clock_event_ddata *data = + container_of(evtdev, struct stm32_clock_event_ddata, evtdev); + + writel_relaxed(evt, data->base + TIM_ARR); + writel_relaxed(TIM_CR1_ARPE | TIM_CR1_OPM | TIM_CR1_CEN, + data->base + TIM_CR1); + + return 0; +} + +static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id) +{ + struct stm32_clock_event_ddata *data = dev_id; + + writel_relaxed(0, data->base + TIM_SR); + + data->evtdev.event_handler(&data->evtdev); + + return IRQ_HANDLED; +} + +static struct stm32_clock_event_ddata clock_event_ddata = { + .evtdev = { + .name = "stm32 clockevent", + .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, + .set_mode = stm32_clock_event_set_mode, + .set_next_event = stm32_clock_event_set_next_event, + .rating = 200, + }, +}; + +static void __init stm32_clockevent_init(struct device_node *np) +{ + struct stm32_clock_event_ddata *data = &clock_event_ddata; + struct clk *clk; + struct reset_control *rstc; + unsigned long rate, max_delta; + int irq, ret, bits, prescaler = 1; + + clk = of_clk_get(np, 0); + if (IS_ERR(clk)) { + ret = PTR_ERR(clk); + pr_err("failed to get clock for clockevent (%d)\n", ret); + goto err_clk_get; + } + + ret = clk_prepare_enable(clk); + if (ret) { + pr_err("failed to enable timer clock for clockevent (%d)\n", + ret); + goto err_clk_enable; + } + + rate = clk_get_rate(clk); + + rstc = of_reset_control_get(np, NULL); + if (!IS_ERR(rstc)) { + reset_control_assert(rstc); + reset_control_deassert(rstc); + } + + data->base = of_iomap(np, 0); + if (!data->base) { + pr_err("failed to map registers for clockevent\n"); + goto err_iomap; + } + + irq = irq_of_parse_and_map(np, 0); + if (!irq) { + pr_err("%s: failed to get irq.\n", np->full_name); + goto err_get_irq; + } + + /* Detect whether the timer is 16 or 32 bits */ + writel_relaxed(~0UL, data->base + TIM_ARR); + max_delta = readl_relaxed(data->base + TIM_ARR); + if (max_delta == ~0UL) { + prescaler = 1; + bits = 32; + } else { + prescaler = 1024; + bits = 16; + } + writel_relaxed(0, data->base + TIM_ARR); + + writel_relaxed(prescaler - 1, data->base + TIM_PSC); + writel_relaxed(TIM_EGR_UG, data->base + TIM_EGR); + writel_relaxed(TIM_DIER_UIE, data->base + TIM_DIER); + writel_relaxed(0, data->base + TIM_SR); + + data->periodic_top = DIV_ROUND_CLOSEST(rate, prescaler * HZ); + + clockevents_config_and_register(&data->evtdev, + DIV_ROUND_CLOSEST(rate, prescaler), + 0x1, max_delta); + + ret = request_irq(irq, stm32_clock_event_handler, IRQF_TIMER, + "stm32 clockevent", data); + if (ret) { + pr_err("%s: failed to request irq.\n", np->full_name); + goto err_get_irq; + } + + pr_info("%s: STM32 clockevent driver initialized (%d bits)\n", + np->full_name, bits); + + return; + +err_get_irq: + iounmap(data->base); +err_iomap: + clk_disable_unprepare(clk); +err_clk_enable: + clk_put(clk); +err_clk_get: + return; +} + +CLOCKSOURCE_OF_DECLARE(stm32, "st,stm32-timer", stm32_clockevent_init);