* [PATCH v3 0/2] clockevent: add low power STM32 timer
@ 2020-01-28 12:07 Benjamin Gaignard
2020-01-28 12:07 ` [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings Benjamin Gaignard
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Benjamin Gaignard @ 2020-01-28 12:07 UTC (permalink / raw)
To: daniel.lezcano, tglx, robh+dt, mark.rutland, mcoquelin.stm32,
alexandre.torgue, linux, p.paillet, linus.walleij
Cc: devicetree, linux-stm32, linux-arm-kernel, fabrice.gasnier,
Benjamin Gaignard
This series add low power timer as boadcast clockevent device.
Low power timer could runs even when CPUs are in idle mode and
could wakeup them.
version 3:
- fix timer set sequence
- don't forget to free irq on remove function
- use devm_kzalloc to simplify errors handling in probe function
version 2:
- stm32 clkevent driver is now a child of the stm32 lp timer node
- add a probe function and adpat the driver to use regmap provide
by it parent
- stop using timer_of helpers
- document the bindings inside stm32 lptimer yaml
Benjamin Gaignard (2):
dt-bindings: mfd: Document STM32 low power clkevent bindings
clocksource: Add Low Power STM32 timers driver
.../devicetree/bindings/mfd/st,stm32-lptimer.yaml | 14 ++
drivers/clocksource/Kconfig | 4 +
drivers/clocksource/Makefile | 1 +
drivers/clocksource/timer-stm32-lp.c | 248 +++++++++++++++++++++
4 files changed, 267 insertions(+)
create mode 100644 drivers/clocksource/timer-stm32-lp.c
--
2.15.0
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings 2020-01-28 12:07 [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin Gaignard @ 2020-01-28 12:07 ` Benjamin Gaignard 2020-02-12 16:51 ` Daniel Lezcano 2020-01-28 12:07 ` [PATCH v3 2/2] clocksource: Add Low Power STM32 timers driver Benjamin Gaignard 2020-02-10 9:02 ` [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin GAIGNARD 2 siblings, 1 reply; 8+ messages in thread From: Benjamin Gaignard @ 2020-01-28 12:07 UTC (permalink / raw) To: daniel.lezcano, tglx, robh+dt, mark.rutland, mcoquelin.stm32, alexandre.torgue, linux, p.paillet, linus.walleij Cc: devicetree, linux-stm32, linux-arm-kernel, fabrice.gasnier, Benjamin Gaignard Add a subnode to STM low power timer bindings to support clkevent driver Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com> --- .../devicetree/bindings/mfd/st,stm32-lptimer.yaml | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml b/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml index 1a4cc5f3fb33..535e0b40cdf9 100644 --- a/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml +++ b/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml @@ -81,6 +81,16 @@ patternProperties: required: - compatible + clkevent: + type: object + + properties: + compatible: + const: st,stm32-clkevent-lp + + required: + - compatible + required: - "#address-cells" - "#size-cells" @@ -115,6 +125,10 @@ examples: counter { compatible = "st,stm32-lptimer-counter"; }; + + clkevent { + compatible = "st,stm32-clkevent-lp"; + }; }; ... -- 2.15.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings 2020-01-28 12:07 ` [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings Benjamin Gaignard @ 2020-02-12 16:51 ` Daniel Lezcano 2020-02-12 17:07 ` Benjamin GAIGNARD 0 siblings, 1 reply; 8+ messages in thread From: Daniel Lezcano @ 2020-02-12 16:51 UTC (permalink / raw) To: Benjamin Gaignard Cc: tglx, robh+dt, mark.rutland, mcoquelin.stm32, alexandre.torgue, linux, p.paillet, linus.walleij, devicetree, linux-stm32, linux-arm-kernel, fabrice.gasnier On Tue, Jan 28, 2020 at 01:07:01PM +0100, Benjamin Gaignard wrote: > Add a subnode to STM low power timer bindings to support clkevent driver clkevent is Linux specific. > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com> > --- > .../devicetree/bindings/mfd/st,stm32-lptimer.yaml | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml b/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml > index 1a4cc5f3fb33..535e0b40cdf9 100644 > --- a/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml > +++ b/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml > @@ -81,6 +81,16 @@ patternProperties: > required: > - compatible > > + clkevent: > + type: object > + > + properties: > + compatible: > + const: st,stm32-clkevent-lp > + > + required: > + - compatible > + > required: > - "#address-cells" > - "#size-cells" > @@ -115,6 +125,10 @@ examples: > counter { > compatible = "st,stm32-lptimer-counter"; > }; > + > + clkevent { > + compatible = "st,stm32-clkevent-lp"; > + }; > }; > > ... > -- > 2.15.0 > -- <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 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings 2020-02-12 16:51 ` Daniel Lezcano @ 2020-02-12 17:07 ` Benjamin GAIGNARD 2020-02-12 19:23 ` Daniel Lezcano 0 siblings, 1 reply; 8+ messages in thread From: Benjamin GAIGNARD @ 2020-02-12 17:07 UTC (permalink / raw) To: Daniel Lezcano Cc: tglx, robh+dt, mark.rutland, mcoquelin.stm32, Alexandre TORGUE, linux, Pascal PAILLET-LME, linus.walleij, devicetree, linux-stm32, linux-arm-kernel, Fabrice GASNIER On 2/12/20 5:51 PM, Daniel Lezcano wrote: > On Tue, Jan 28, 2020 at 01:07:01PM +0100, Benjamin Gaignard wrote: >> Add a subnode to STM low power timer bindings to support clkevent driver > clkevent is Linux specific. Does 'event' or 'broadcast' would sound better ? > >> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com> >> --- >> .../devicetree/bindings/mfd/st,stm32-lptimer.yaml | 14 ++++++++++++++ >> 1 file changed, 14 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml b/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml >> index 1a4cc5f3fb33..535e0b40cdf9 100644 >> --- a/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml >> +++ b/Documentation/devicetree/bindings/mfd/st,stm32-lptimer.yaml >> @@ -81,6 +81,16 @@ patternProperties: >> required: >> - compatible >> >> + clkevent: >> + type: object >> + >> + properties: >> + compatible: >> + const: st,stm32-clkevent-lp >> + >> + required: >> + - compatible >> + >> required: >> - "#address-cells" >> - "#size-cells" >> @@ -115,6 +125,10 @@ examples: >> counter { >> compatible = "st,stm32-lptimer-counter"; >> }; >> + >> + clkevent { >> + compatible = "st,stm32-clkevent-lp"; >> + }; >> }; >> >> ... >> -- >> 2.15.0 >> ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings 2020-02-12 17:07 ` Benjamin GAIGNARD @ 2020-02-12 19:23 ` Daniel Lezcano 0 siblings, 0 replies; 8+ messages in thread From: Daniel Lezcano @ 2020-02-12 19:23 UTC (permalink / raw) To: Benjamin GAIGNARD Cc: tglx, robh+dt, mark.rutland, mcoquelin.stm32, Alexandre TORGUE, linux, Pascal PAILLET-LME, linus.walleij, devicetree, linux-stm32, linux-arm-kernel, Fabrice GASNIER Hi Benjamin, On Wed, Feb 12, 2020 at 05:07:49PM +0000, Benjamin GAIGNARD wrote: > On 2/12/20 5:51 PM, Daniel Lezcano wrote: > > On Tue, Jan 28, 2020 at 01:07:01PM +0100, Benjamin Gaignard wrote: > >> Add a subnode to STM low power timer bindings to support clkevent driver > > clkevent is Linux specific. > Does 'event' or 'broadcast' would sound better ? As this describes the timer hardware block of the mfd, I would say 'timer' is more appropriate. ^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v3 2/2] clocksource: Add Low Power STM32 timers driver 2020-01-28 12:07 [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin Gaignard 2020-01-28 12:07 ` [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings Benjamin Gaignard @ 2020-01-28 12:07 ` Benjamin Gaignard 2020-02-12 19:20 ` Daniel Lezcano 2020-02-10 9:02 ` [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin GAIGNARD 2 siblings, 1 reply; 8+ messages in thread From: Benjamin Gaignard @ 2020-01-28 12:07 UTC (permalink / raw) To: daniel.lezcano, tglx, robh+dt, mark.rutland, mcoquelin.stm32, alexandre.torgue, linux, p.paillet, linus.walleij Cc: devicetree, linux-stm32, linux-arm-kernel, fabrice.gasnier, Benjamin Gaignard From: Benjamin Gaignard <benjamin.gaignard@linaro.org> Implement clock event driver using low power STM32 timers. Low power timers counter s running even in when CPU is in stop mode. It could be used as clock event broadcaster to wake up CPUs but not like a clocksource because each it rise an interrupt the counter restart from 0. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Signed-off-by: Pascal Paillet <p.paillet@st.com> --- version 3: - fix timer set sequence - don't forget to free irq on remove function - use devm_kzalloc to simplify errors handling in probe function drivers/clocksource/Kconfig | 4 + drivers/clocksource/Makefile | 1 + drivers/clocksource/timer-stm32-lp.c | 248 +++++++++++++++++++++++++++++++++++ 3 files changed, 253 insertions(+) create mode 100644 drivers/clocksource/timer-stm32-lp.c diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 5fdd76cb1768..d9d06c14777d 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -292,6 +292,10 @@ config CLKSRC_STM32 select CLKSRC_MMIO select TIMER_OF +config CLKSRC_STM32_LP + bool "Low power clocksource for STM32 SoCs" + depends on OF && ARM && (MACH_STM32MP157 || COMPILE_TEST) + config CLKSRC_MPS2 bool "Clocksource for MPS2 SoCs" if COMPILE_TEST depends on GENERIC_SCHED_CLOCK diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 4dfe4225ece7..c6eef37be9cc 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_BCM_KONA_TIMER) += bcm_kona_timer.o obj-$(CONFIG_CADENCE_TTC_TIMER) += timer-cadence-ttc.o obj-$(CONFIG_CLKSRC_EFM32) += timer-efm32.o obj-$(CONFIG_CLKSRC_STM32) += timer-stm32.o +obj-$(CONFIG_CLKSRC_STM32_LP) += timer-stm32-lp.o obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o obj-$(CONFIG_CLKSRC_LPC32XX) += timer-lpc32xx.o obj-$(CONFIG_CLKSRC_MPS2) += mps2-timer.o diff --git a/drivers/clocksource/timer-stm32-lp.c b/drivers/clocksource/timer-stm32-lp.c new file mode 100644 index 000000000000..b6de1ca9e115 --- /dev/null +++ b/drivers/clocksource/timer-stm32-lp.c @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics 2019 - All Rights Reserved + * Authors: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics. + * Pascal Paillet <p.paillet@st.com> for STMicroelectronics. + */ + +#include <linux/clk.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/delay.h> +#include <linux/irq.h> +#include <linux/interrupt.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/mfd/stm32-lptimer.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define LPTIM_ICR 0x04 +#define ICR_ARRMCF BIT(1) + +#define LPTIM_IER 0x08 +#define IER_ARRMIE BIT(1) + +#define LPTIM_CFGR 0x0C +#define CFGR_PSC_OFFSET 9 + +#define LPTIM_CR 0x10 +#define CR_ENABLE BIT(0) +#define CR_SNGSTRT BIT(1) +#define CR_CNTSTRT BIT(2) + +#define LPTIM_CMP 0x14 +#define LPTIM_ARR 0x18 + +#define STM32_LP_BITS 16 +#define STM32_LP_RATING 400 +#define STM32_CLKRATE (32000 * HZ) +#define TIMER_MAX_VAL (BIT(STM32_LP_BITS) - 1) +#define STM32_LP_MAX_PSC 7 + +struct stm32_lp_private { + struct regmap *reg; + struct clk *clk; + struct clock_event_device clkevt; + unsigned long rate; + unsigned long period; +}; + +static struct stm32_lp_private* +to_priv(struct clock_event_device *clkevt) +{ + return container_of(clkevt, struct stm32_lp_private, clkevt); +} + +static int stm32_clkevent_lp_shutdown(struct clock_event_device *clkevt) +{ + struct stm32_lp_private *priv = to_priv(clkevt); + + regmap_write(priv->reg, LPTIM_CR, 0); + regmap_write(priv->reg, LPTIM_IER, 0); + /* clear pending flags */ + regmap_write(priv->reg, LPTIM_ICR, ICR_ARRMCF); + + return 0; +} + +static int stm32_clkevent_lp_set_timer(unsigned long evt, + struct clock_event_device *clkevt, + int is_periodic) +{ + struct stm32_lp_private *priv = to_priv(clkevt); + + /* disable TIMER */ + regmap_write(priv->reg, LPTIM_CR, 0); + /* enable ARR interrupt */ + regmap_write(priv->reg, LPTIM_IER, IER_ARRMIE); + /* enable LPTIMER*/ + regmap_write(priv->reg, LPTIM_CR, CR_ENABLE); + /* set nex event counter */ + regmap_write(priv->reg, LPTIM_ARR, evt); + /* reset counter */ + regmap_write(priv->reg, LPTIM_CMP, 0); + + /* start counter */ + if (is_periodic) + regmap_write(priv->reg, LPTIM_CR, CR_CNTSTRT | CR_ENABLE); + else + regmap_write(priv->reg, LPTIM_CR, CR_SNGSTRT | CR_ENABLE); + + return 0; +} + +static int stm32_clkevent_lp_set_next_event(unsigned long evt, + struct clock_event_device *clkevt) +{ + return stm32_clkevent_lp_set_timer(evt, clkevt, + clockevent_state_periodic(clkevt)); +} + +static int stm32_clkevent_lp_set_periodic(struct clock_event_device *clkevt) +{ + struct stm32_lp_private *priv = to_priv(clkevt); + + return stm32_clkevent_lp_set_timer(priv->period, clkevt, true); +} + +static int stm32_clkevent_lp_set_oneshot(struct clock_event_device *clkevt) +{ + struct stm32_lp_private *priv = to_priv(clkevt); + + return stm32_clkevent_lp_set_timer(priv->period, clkevt, false); +} + +static irqreturn_t stm32_clkevent_lp_irq_handler(int irq, void *dev_id) +{ + struct clock_event_device *clkevt = (struct clock_event_device *)dev_id; + struct stm32_lp_private *priv = to_priv(clkevt); + + regmap_write(priv->reg, LPTIM_ICR, ICR_ARRMCF); + + clkevt->event_handler(clkevt); + + return IRQ_HANDLED; +} + +/** + * stm32_clkevent_lp_set_prescaler - Compute and set the prescaler register + * @priv: a pointer to a timer-of structure + * + * Compute the prescaler to always target a 32Khz timer rate + */ +static void stm32_clkevent_lp_set_prescaler(struct stm32_lp_private *priv) +{ + int i; + + for (i = 0; i <= STM32_LP_MAX_PSC; i++) { + if (DIV_ROUND_CLOSEST(priv->rate, 1 << i) < STM32_CLKRATE) + break; + } + + regmap_write(priv->reg, LPTIM_CFGR, i << CFGR_PSC_OFFSET); + + /* Adjust rate and period given the prescaler value */ + priv->rate = DIV_ROUND_CLOSEST(priv->rate, (1 << i)); + priv->period = DIV_ROUND_UP(priv->rate, HZ); +} + +static int stm32_clkevent_lp_init(struct stm32_lp_private *priv, + struct device_node *np) +{ + int ret; + + priv->clkevt.name = np->full_name; + priv->clkevt.cpumask = cpu_possible_mask; + priv->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | + CLOCK_EVT_FEAT_ONESHOT; + priv->clkevt.set_state_shutdown = stm32_clkevent_lp_shutdown; + priv->clkevt.set_state_periodic = stm32_clkevent_lp_set_periodic; + priv->clkevt.set_state_oneshot = stm32_clkevent_lp_set_oneshot; + priv->clkevt.set_next_event = stm32_clkevent_lp_set_next_event; + priv->clkevt.rating = STM32_LP_RATING; + + priv->clkevt.irq = irq_of_parse_and_map(np, 0); + if (!priv->clkevt.irq) + return -EINVAL; + + ret = request_irq(priv->clkevt.irq, stm32_clkevent_lp_irq_handler, + IRQF_TIMER, np->full_name, &priv->clkevt); + if (ret) + return ret; + + clockevents_config_and_register(&priv->clkevt, priv->rate, 0x1, + TIMER_MAX_VAL); + + return 0; +} + +static int stm32_clkevent_lp_probe(struct platform_device *pdev) +{ + struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent); + struct stm32_lp_private *priv; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->reg = ddata->regmap; + priv->clk = ddata->clk; + ret = clk_prepare_enable(priv->clk); + if (ret) + return -EINVAL; + + priv->rate = clk_get_rate(priv->clk); + if (!priv->rate) + goto out_clk_disable; + + stm32_clkevent_lp_set_prescaler(priv); + + ret = stm32_clkevent_lp_init(priv, pdev->dev.parent->of_node); + if (ret) + goto out_clk_disable; + + platform_set_drvdata(pdev, priv); + + return 0; + +out_clk_disable: + clk_disable_unprepare(priv->clk); + + return -EINVAL; +} + +static int stm32_clkevent_lp_remove(struct platform_device *pdev) +{ + struct stm32_lp_private *priv = platform_get_drvdata(pdev); + + clk_disable_unprepare(priv->clk); + free_irq(priv->clkevt.irq, &priv->clkevt); + + return 0; +} + +static const struct of_device_id stm32_clkevent_lp_of_match[] = { + { .compatible = "st,stm32-clkevent-lp", }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_clkevent_lp_of_match); + +static struct platform_driver stm32_clkevent_lp_driver = { + .probe = stm32_clkevent_lp_probe, + .remove = stm32_clkevent_lp_remove, + .driver = { + .name = "stm32-clkevent-lp", + .of_match_table = of_match_ptr(stm32_clkevent_lp_of_match), + }, +}; +module_platform_driver(stm32_clkevent_lp_driver); + +MODULE_ALIAS("platform:stm32-clkevent-lp"); +MODULE_DESCRIPTION("STMicroelectronics STM32 clockevent LP driver"); +MODULE_LICENSE("GPL v2"); -- 2.15.0 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v3 2/2] clocksource: Add Low Power STM32 timers driver 2020-01-28 12:07 ` [PATCH v3 2/2] clocksource: Add Low Power STM32 timers driver Benjamin Gaignard @ 2020-02-12 19:20 ` Daniel Lezcano 0 siblings, 0 replies; 8+ messages in thread From: Daniel Lezcano @ 2020-02-12 19:20 UTC (permalink / raw) To: Benjamin Gaignard Cc: tglx, robh+dt, mark.rutland, mcoquelin.stm32, alexandre.torgue, linux, p.paillet, linus.walleij, devicetree, linux-stm32, linux-arm-kernel, fabrice.gasnier, Benjamin Gaignard Hi Benjamin, On Tue, Jan 28, 2020 at 01:07:02PM +0100, Benjamin Gaignard wrote: > From: Benjamin Gaignard <benjamin.gaignard@linaro.org> > > Implement clock event driver using low power STM32 timers. > Low power timers counter s running even in when CPU is in stop mode. Can you fix the sentence above? > It could be used as clock event broadcaster to wake up CPUs but not like > a clocksource because each it rise an interrupt the counter restart from 0. Please give a description of the timer (eg. e37e45934afed). > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> > Signed-off-by: Pascal Paillet <p.paillet@st.com> > --- > version 3: > - fix timer set sequence > - don't forget to free irq on remove function > - use devm_kzalloc to simplify errors handling in probe function > > drivers/clocksource/Kconfig | 4 + > drivers/clocksource/Makefile | 1 + > drivers/clocksource/timer-stm32-lp.c | 248 +++++++++++++++++++++++++++++++++++ > 3 files changed, 253 insertions(+) > create mode 100644 drivers/clocksource/timer-stm32-lp.c > > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig > index 5fdd76cb1768..d9d06c14777d 100644 > --- a/drivers/clocksource/Kconfig > +++ b/drivers/clocksource/Kconfig > @@ -292,6 +292,10 @@ config CLKSRC_STM32 > select CLKSRC_MMIO > select TIMER_OF > > +config CLKSRC_STM32_LP > + bool "Low power clocksource for STM32 SoCs" (silent option) > + depends on OF && ARM && (MACH_STM32MP157 || COMPILE_TEST) Do you really want to make this option? This timer belongs to a mfd, so if the mfd is enabled it should enable the timer also, no ? > + > config CLKSRC_MPS2 > bool "Clocksource for MPS2 SoCs" if COMPILE_TEST > depends on GENERIC_SCHED_CLOCK > diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile > index 4dfe4225ece7..c6eef37be9cc 100644 > --- a/drivers/clocksource/Makefile > +++ b/drivers/clocksource/Makefile > @@ -44,6 +44,7 @@ obj-$(CONFIG_BCM_KONA_TIMER) += bcm_kona_timer.o > obj-$(CONFIG_CADENCE_TTC_TIMER) += timer-cadence-ttc.o > obj-$(CONFIG_CLKSRC_EFM32) += timer-efm32.o > obj-$(CONFIG_CLKSRC_STM32) += timer-stm32.o > +obj-$(CONFIG_CLKSRC_STM32_LP) += timer-stm32-lp.o > obj-$(CONFIG_CLKSRC_EXYNOS_MCT) += exynos_mct.o > obj-$(CONFIG_CLKSRC_LPC32XX) += timer-lpc32xx.o > obj-$(CONFIG_CLKSRC_MPS2) += mps2-timer.o > diff --git a/drivers/clocksource/timer-stm32-lp.c b/drivers/clocksource/timer-stm32-lp.c > new file mode 100644 > index 000000000000..b6de1ca9e115 > --- /dev/null > +++ b/drivers/clocksource/timer-stm32-lp.c > @@ -0,0 +1,248 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) STMicroelectronics 2019 - All Rights Reserved > + * Authors: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics. > + * Pascal Paillet <p.paillet@st.com> for STMicroelectronics. > + */ > + > +#include <linux/clk.h> > +#include <linux/clocksource.h> > +#include <linux/clockchips.h> > +#include <linux/delay.h> > +#include <linux/irq.h> > +#include <linux/interrupt.h> > +#include <linux/iopoll.h> > +#include <linux/kernel.h> > +#include <linux/mfd/stm32-lptimer.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/of_irq.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> Please check the headers above, all are not needed IMO. > +#define LPTIM_ICR 0x04 > +#define ICR_ARRMCF BIT(1) > + > +#define LPTIM_IER 0x08 > +#define IER_ARRMIE BIT(1) > + > +#define LPTIM_CFGR 0x0C > +#define CFGR_PSC_OFFSET 9 > + > +#define LPTIM_CR 0x10 > +#define CR_ENABLE BIT(0) > +#define CR_SNGSTRT BIT(1) > +#define CR_CNTSTRT BIT(2) > + > +#define LPTIM_CMP 0x14 > +#define LPTIM_ARR 0x18 > + > +#define STM32_LP_BITS 16 > +#define STM32_LP_RATING 400 > +#define STM32_CLKRATE (32000 * HZ) > +#define TIMER_MAX_VAL (BIT(STM32_LP_BITS) - 1) STM32 prefix missing > +#define STM32_LP_MAX_PSC 7 > + > +struct stm32_lp_private { > + struct regmap *reg; > + struct clk *clk; > + struct clock_event_device clkevt; > + unsigned long rate; This field can be saved if the parameter is passed to the set_prescalar function. > + unsigned long period; > +}; > + > +static struct stm32_lp_private* > +to_priv(struct clock_event_device *clkevt) > +{ > + return container_of(clkevt, struct stm32_lp_private, clkevt); > +} > + > +static int stm32_clkevent_lp_shutdown(struct clock_event_device *clkevt) > +{ > + struct stm32_lp_private *priv = to_priv(clkevt); > + > + regmap_write(priv->reg, LPTIM_CR, 0); > + regmap_write(priv->reg, LPTIM_IER, 0); > + /* clear pending flags */ > + regmap_write(priv->reg, LPTIM_ICR, ICR_ARRMCF); > + > + return 0; > +} > + > +static int stm32_clkevent_lp_set_timer(unsigned long evt, > + struct clock_event_device *clkevt, > + int is_periodic) > +{ > + struct stm32_lp_private *priv = to_priv(clkevt); > + > + /* disable TIMER */ > + regmap_write(priv->reg, LPTIM_CR, 0); > + /* enable ARR interrupt */ > + regmap_write(priv->reg, LPTIM_IER, IER_ARRMIE); > + /* enable LPTIMER*/ > + regmap_write(priv->reg, LPTIM_CR, CR_ENABLE); > + /* set nex event counter */ > + regmap_write(priv->reg, LPTIM_ARR, evt); > + /* reset counter */ > + regmap_write(priv->reg, LPTIM_CMP, 0); > + > + /* start counter */ > + if (is_periodic) > + regmap_write(priv->reg, LPTIM_CR, CR_CNTSTRT | CR_ENABLE); > + else > + regmap_write(priv->reg, LPTIM_CR, CR_SNGSTRT | CR_ENABLE); Please merge all these calls to regmap_write into a single one to reduce contention. > + return 0; > +} > + > +static int stm32_clkevent_lp_set_next_event(unsigned long evt, > + struct clock_event_device *clkevt) > +{ > + return stm32_clkevent_lp_set_timer(evt, clkevt, > + clockevent_state_periodic(clkevt)); > +} > + > +static int stm32_clkevent_lp_set_periodic(struct clock_event_device *clkevt) > +{ > + struct stm32_lp_private *priv = to_priv(clkevt); > + > + return stm32_clkevent_lp_set_timer(priv->period, clkevt, true); > +} > + > +static int stm32_clkevent_lp_set_oneshot(struct clock_event_device *clkevt) > +{ > + struct stm32_lp_private *priv = to_priv(clkevt); > + > + return stm32_clkevent_lp_set_timer(priv->period, clkevt, false); > +} > + > +static irqreturn_t stm32_clkevent_lp_irq_handler(int irq, void *dev_id) > +{ > + struct clock_event_device *clkevt = (struct clock_event_device *)dev_id; > + struct stm32_lp_private *priv = to_priv(clkevt); > + > + regmap_write(priv->reg, LPTIM_ICR, ICR_ARRMCF); > + > + clkevt->event_handler(clkevt); > + > + return IRQ_HANDLED; > +} > + > +/** This is a kerneldoc format > + * stm32_clkevent_lp_set_prescaler - Compute and set the prescaler register > + * @priv: a pointer to a timer-of structure > + * > + * Compute the prescaler to always target a 32Khz timer rate > + */ Given these are static callbacks, you can drop the function description by moving it to a comment in the function. > +static void stm32_clkevent_lp_set_prescaler(struct stm32_lp_private *priv) > +{ > + int i; > + > + for (i = 0; i <= STM32_LP_MAX_PSC; i++) { > + if (DIV_ROUND_CLOSEST(priv->rate, 1 << i) < STM32_CLKRATE) > + break; > + } > + > + regmap_write(priv->reg, LPTIM_CFGR, i << CFGR_PSC_OFFSET); > + > + /* Adjust rate and period given the prescaler value */ > + priv->rate = DIV_ROUND_CLOSEST(priv->rate, (1 << i)); > + priv->period = DIV_ROUND_UP(priv->rate, HZ); > +} > + > +static int stm32_clkevent_lp_init(struct stm32_lp_private *priv, > + struct device_node *np) > +{ > + int ret; > + > + priv->clkevt.name = np->full_name; > + priv->clkevt.cpumask = cpu_possible_mask; > + priv->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | > + CLOCK_EVT_FEAT_ONESHOT; > + priv->clkevt.set_state_shutdown = stm32_clkevent_lp_shutdown; > + priv->clkevt.set_state_periodic = stm32_clkevent_lp_set_periodic; > + priv->clkevt.set_state_oneshot = stm32_clkevent_lp_set_oneshot; > + priv->clkevt.set_next_event = stm32_clkevent_lp_set_next_event; > + priv->clkevt.rating = STM32_LP_RATING; > + > + priv->clkevt.irq = irq_of_parse_and_map(np, 0); > + if (!priv->clkevt.irq) > + return -EINVAL; > + > + ret = request_irq(priv->clkevt.irq, stm32_clkevent_lp_irq_handler, > + IRQF_TIMER, np->full_name, &priv->clkevt); > + if (ret) > + return ret; May be move the node parsing to the 'probe' function and use demv_request_irq (or use timer-of)? Pass the timer name as parameter to this function? > + > + clockevents_config_and_register(&priv->clkevt, priv->rate, 0x1, > + TIMER_MAX_VAL); > + > + return 0; > +} > + > +static int stm32_clkevent_lp_probe(struct platform_device *pdev) > +{ > + struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent); > + struct stm32_lp_private *priv; > + int ret; > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->reg = ddata->regmap; > + priv->clk = ddata->clk; > + ret = clk_prepare_enable(priv->clk); > + if (ret) > + return -EINVAL; > + > + priv->rate = clk_get_rate(priv->clk); > + if (!priv->rate) > + goto out_clk_disable; > + > + stm32_clkevent_lp_set_prescaler(priv); > + > + ret = stm32_clkevent_lp_init(priv, pdev->dev.parent->of_node); > + if (ret) > + goto out_clk_disable; > + > + platform_set_drvdata(pdev, priv); See if this is needed given the comment below about the removal. > + return 0; > + > +out_clk_disable: > + clk_disable_unprepare(priv->clk); > + > + return -EINVAL; > +} > + > +static int stm32_clkevent_lp_remove(struct platform_device *pdev) > +{ > + struct stm32_lp_private *priv = platform_get_drvdata(pdev); > + > + clk_disable_unprepare(priv->clk); > + free_irq(priv->clkevt.irq, &priv->clkevt); > + > + return 0; > +} This is broken IMO, the time framework will continue considering the previously registered clockevent as available. You should consider converting the mfd to a bool instead of a tristate (and remove the dead code). > +static const struct of_device_id stm32_clkevent_lp_of_match[] = { > + { .compatible = "st,stm32-clkevent-lp", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, stm32_clkevent_lp_of_match); > + > +static struct platform_driver stm32_clkevent_lp_driver = { > + .probe = stm32_clkevent_lp_probe, > + .remove = stm32_clkevent_lp_remove, > + .driver = { > + .name = "stm32-clkevent-lp", > + .of_match_table = of_match_ptr(stm32_clkevent_lp_of_match), > + }, > +}; > +module_platform_driver(stm32_clkevent_lp_driver); > + > +MODULE_ALIAS("platform:stm32-clkevent-lp"); > +MODULE_DESCRIPTION("STMicroelectronics STM32 clockevent LP driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.15.0 > -- <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 ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v3 0/2] clockevent: add low power STM32 timer 2020-01-28 12:07 [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin Gaignard 2020-01-28 12:07 ` [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings Benjamin Gaignard 2020-01-28 12:07 ` [PATCH v3 2/2] clocksource: Add Low Power STM32 timers driver Benjamin Gaignard @ 2020-02-10 9:02 ` Benjamin GAIGNARD 2 siblings, 0 replies; 8+ messages in thread From: Benjamin GAIGNARD @ 2020-02-10 9:02 UTC (permalink / raw) To: daniel.lezcano, tglx, robh+dt, mark.rutland, mcoquelin.stm32, Alexandre TORGUE, linux, Pascal PAILLET-LME, linus.walleij Cc: devicetree, linux-stm32, linux-arm-kernel, Fabrice GASNIER On 1/28/20 1:07 PM, Benjamin Gaignard wrote: > This series add low power timer as boadcast clockevent device. > Low power timer could runs even when CPUs are in idle mode and > could wakeup them. Gentle ping to reviewers. Thanks, Benjamin > > version 3: > - fix timer set sequence > - don't forget to free irq on remove function > - use devm_kzalloc to simplify errors handling in probe function > > version 2: > - stm32 clkevent driver is now a child of the stm32 lp timer node > - add a probe function and adpat the driver to use regmap provide > by it parent > - stop using timer_of helpers > - document the bindings inside stm32 lptimer yaml > > Benjamin Gaignard (2): > dt-bindings: mfd: Document STM32 low power clkevent bindings > clocksource: Add Low Power STM32 timers driver > > .../devicetree/bindings/mfd/st,stm32-lptimer.yaml | 14 ++ > drivers/clocksource/Kconfig | 4 + > drivers/clocksource/Makefile | 1 + > drivers/clocksource/timer-stm32-lp.c | 248 +++++++++++++++++++++ > 4 files changed, 267 insertions(+) > create mode 100644 drivers/clocksource/timer-stm32-lp.c > ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-02-12 19:23 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-01-28 12:07 [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin Gaignard 2020-01-28 12:07 ` [PATCH v3 1/2] dt-bindings: mfd: Document STM32 low power clkevent bindings Benjamin Gaignard 2020-02-12 16:51 ` Daniel Lezcano 2020-02-12 17:07 ` Benjamin GAIGNARD 2020-02-12 19:23 ` Daniel Lezcano 2020-01-28 12:07 ` [PATCH v3 2/2] clocksource: Add Low Power STM32 timers driver Benjamin Gaignard 2020-02-12 19:20 ` Daniel Lezcano 2020-02-10 9:02 ` [PATCH v3 0/2] clockevent: add low power STM32 timer Benjamin GAIGNARD
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