Re: [PATCH v4 6/7] IIO: add STM32 timer trigger driver

On Tue, 06 Dec 2016, Benjamin Gaignard wrote:

Timers IPs can be used to generate triggers for other IPs like DAC, ADC or other timers. Each trigger may result of timer internals signals like counter enable, reset or edge, this configuration could be done through "master_mode" device attribute.

A timer device could be triggered by other timers, we use the trigger name and is_stm32_iio_timer_trigger() function to distinguish them and configure IP input switch.

Timer may also decide on which event (edge, level) they could be activated by a trigger, this configuration is done by writing in "slave_mode" device attribute.

Since triggers could also be used by DAC or ADC their names are defined in include/ nux/iio/timer/stm32-timer-trigger.h so those IPs will be able to configure themselves in valid_trigger function

Trigger have a "sampling_frequency" attribute which allow to configure timer sampling frequency without using PWM interface

version 4:

• get triggers configuration from "reg" in DT
• add tables of triggers
• sampling frequency is enable/disable when writing in trigger sampling_frequency attribute
• no more use of interruptions

version 3:

• change compatible to "st,stm32-timer-trigger"
• fix attributes access right
• use string instead of int for master_mode and slave_mode
• document device attributes in sysfs-bus-iio-timer-stm32

version 2:

• keep only one compatible
• use st,input-triggers-names and st,output-triggers-names to know which triggers are accepted and/or create by the device

Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com

.../ABI/testing/sysfs-bus-iio-timer-stm32 | 55 +++ drivers/iio/Kconfig | 2 +- drivers/iio/Makefile | 1 + drivers/iio/timer/Kconfig | 15 + drivers/iio/timer/Makefile | 1 + drivers/iio/timer/stm32-timer-trigger.c | 526 +++++++++++++++++++++ drivers/iio/trigger/Kconfig | 1 - include/linux/iio/timer/stm32-timer-trigger.h | 61 +++ 8 files changed, 660 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 create mode 100644 drivers/iio/timer/Kconfig create mode 100644 drivers/iio/timer/Makefile create mode 100644 drivers/iio/timer/stm32-timer-trigger.c create mode 100644 include/linux/iio/timer/stm32-timer-trigger.h

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 new file mode 100644 index 0000000..26583dd --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 @@ -0,0 +1,55 @@ +What: /sys/bus/iio/devices/iio:deviceX/master_mode_available +KernelVersion: 4.10 +Contact: benjamin.gaignard@st.com +Description:

• Reading returns the list possible master modes which are:
  

• - "reset"     :	The UG bit from the TIMx_EGR register is used as trigger output (TRGO).
  

• - "enable"    : The Counter Enable signal CNT_EN is used as trigger output.
  

• - "update"    : The update event is selected as trigger output.
  

• 		For instance a master timer can then be used as a prescaler for a slave timer.
  

• - "compare_pulse" : The trigger output send a positive pulse when the CC1IF flag is to be set.
  

• - "OC1REF"    : OC1REF signal is used as trigger output.
  

• - "OC2REF"    : OC2REF signal is used as trigger output.
  

• - "OC3REF"    : OC3REF signal is used as trigger output.
  

• - "OC4REF"    : OC4REF signal is used as trigger output.
  

+What: /sys/bus/iio/devices/iio:deviceX/master_mode +KernelVersion: 4.10 +Contact: benjamin.gaignard@st.com +Description:

• Reading returns the current master modes.
  

• Writing set the master mode
  

+What: /sys/bus/iio/devices/iio:deviceX/slave_mode_available +KernelVersion: 4.10 +Contact: benjamin.gaignard@st.com +Description:

• Reading returns the list possible slave modes which are:
  

• - "disabled"  : The prescaler is clocked directly by the internal clock.
  

• - "encoder_1" : Counter counts up/down on TI2FP1 edge depending on TI1FP2 level.
  

• - "encoder_2" : Counter counts up/down on TI1FP2 edge depending on TI2FP1 level.
  

• - "encoder_3" : Counter counts up/down on both TI1FP1 and TI2FP2 edges depending
  

• 		on the level of the other input.
  

• - "reset"     : Rising edge of the selected trigger input reinitializes the counter
  

• 		and generates an update of the registers.
  

• - "gated"     : The counter clock is enabled when the trigger input is high.
  

• 		The counter stops (but is not reset) as soon as the trigger becomes low.
  

• 		Both start and stop of the counter are controlled.
  

• - "trigger"   : The counter starts at a rising edge of the trigger TRGI (but it is not
  

• 		reset). Only the start of the counter is controlled.
  

• - "external_clock": Rising edges of the selected trigger (TRGI) clock the counter.
  

+What: /sys/bus/iio/devices/iio:deviceX/slave_mode +KernelVersion: 4.10 +Contact: benjamin.gaignard@st.com +Description:

• Reading returns the current slave mode.
  

• Writing set the slave mode
  

+What: /sys/bus/iio/devices/triggerX/sampling_frequency +KernelVersion: 4.10 +Contact: benjamin.gaignard@st.com +Description:

• Reading returns the current sampling frequency.
  

• Writing an value different of 0 set and start sampling.
  

• Writing 0 stop sampling.
  

diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig index 6743b18..2de2a80 100644 --- a/drivers/iio/Kconfig +++ b/drivers/iio/Kconfig @@ -90,5 +90,5 @@ source "drivers/iio/potentiometer/Kconfig" source "drivers/iio/pressure/Kconfig" source "drivers/iio/proximity/Kconfig" source "drivers/iio/temperature/Kconfig"

+source "drivers/iio/timer/Kconfig" endif # IIO diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index 87e4c43..b797c08 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -32,4 +32,5 @@ obj-y += potentiometer/ obj-y += pressure/ obj-y += proximity/ obj-y += temperature/ +obj-y += timer/ obj-y += trigger/ diff --git a/drivers/iio/timer/Kconfig b/drivers/iio/timer/Kconfig new file mode 100644 index 0000000..3033869 --- /dev/null +++ b/drivers/iio/timer/Kconfig @@ -0,0 +1,15 @@ +# +# Timers drivers

+menu "Timers"

+config IIO_STM32_TIMER_TRIGGER

• tristate "STM32 Timer Trigger"
• depends on ARCH_STM32 || COMPILE_TEST
• depends on OF
• depends on MFD_STM32_GP_TIMER
• select IIO_TRIGGERED_EVENT
• help

•  Select this option to enable STM32 Timer Trigger
  

+endmenu diff --git a/drivers/iio/timer/Makefile b/drivers/iio/timer/Makefile new file mode 100644 index 0000000..4ad95ec9 --- /dev/null +++ b/drivers/iio/timer/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_IIO_STM32_TIMER_TRIGGER) += stm32-timer-trigger.o diff --git a/drivers/iio/timer/stm32-timer-trigger.c b/drivers/iio/timer/stm32-timer-trigger.c new file mode 100644 index 0000000..58fba33 --- /dev/null +++ b/drivers/iio/timer/stm32-timer-trigger.c @@ -0,0 +1,526 @@ +/*

• • Copyright (C) STMicroelectronics 2016
• • Author: Benjamin Gaignard benjamin.gaignard@st.com
• • License terms: GNU General Public License (GPL), version 2
• */

+#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/timer/stm32-timer-trigger.h> +#include <linux/iio/trigger.h> +#include <linux/iio/triggered_event.h> +#include <linux/interrupt.h> +#include <linux/mfd/stm32-gptimer.h> +#include <linux/module.h> +#include <linux/platform_device.h>

+static const char * const triggers0[] = {

• TIM1_TRGO, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4, NULL,

+};

+static const char * const triggers1[] = {

• TIM2_TRGO, TIM2_CH1, TIM2_CH2, TIM2_CH3, TIM2_CH4, NULL,

+};

+static const char * const triggers2[] = {

• TIM3_TRGO, TIM3_CH1, TIM3_CH2, TIM3_CH3, TIM3_CH4, NULL,

+};

+static const char * const triggers3[] = {

• TIM4_TRGO, TIM4_CH1, TIM4_CH2, TIM4_CH3, TIM4_CH4, NULL,

+};

+static const char * const triggers4[] = {

• TIM5_TRGO, TIM5_CH1, TIM5_CH2, TIM5_CH3, TIM5_CH4, NULL,

+};

+static const char * const triggers5[] = {

• TIM6_TRGO, NULL,

+};

+static const char * const triggers6[] = {

• TIM7_TRGO, NULL,

+};

+static const char * const triggers7[] = {

• TIM8_TRGO, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4, NULL,

+};

+static const char * const triggers8[] = {

• TIM9_TRGO, TIM9_CH1, TIM9_CH2, NULL,

+};

+static const char * const triggers9[] = {

• TIM12_TRGO, TIM12_CH1, TIM12_CH2, NULL,

+};

+static const void *triggers_table[] = {

• triggers0,
• triggers1,
• triggers2,
• triggers3,
• triggers4,
• triggers5,
• triggers6,
• triggers7,
• triggers8,
• triggers9,

+};

What about:

static const char * const triggers[][] = { { TIM1_TRGO, TIM1_CH1, TIM1_CH2, TIM1_CH3, TIM1_CH4, NULL }, { TIM2_TRGO, TIM2_CH1, TIM2_CH2, TIM2_CH3, TIM2_CH4, NULL }, { TIM3_TRGO, TIM3_CH1, TIM3_CH2, TIM3_CH3, TIM3_CH4, NULL }, { TIM4_TRGO, TIM4_CH1, TIM4_CH2, TIM4_CH3, TIM4_CH4, NULL }, { TIM5_TRGO, TIM5_CH1, TIM5_CH2, TIM5_CH3, TIM5_CH4, NULL }, { TIM6_TRGO, NULL }, { TIM7_TRGO, NULL }, { TIM8_TRGO, TIM8_CH1, TIM8_CH2, TIM8_CH3, TIM8_CH4, NULL }, { TIM9_TRGO, TIM9_CH1, TIM9_CH2, NULL }, { TIM12_TRGO, TIM12_CH1, TIM12_CH2, NULL } };

+static const char * const valids0[] = {

• TIM5_TRGO, TIM2_TRGO, TIM4_TRGO, TIM3_TRGO, NULL,

+};

+static const char * const valids1[] = {

• TIM1_TRGO, TIM8_TRGO, TIM3_TRGO, TIM4_TRGO, NULL,

+};

+static const char * const valids2[] = {

• TIM1_TRGO, TIM8_TRGO, TIM5_TRGO, TIM4_TRGO, NULL,

+};

+static const char * const valids3[] = {

• TIM1_TRGO, TIM2_TRGO, TIM3_TRGO, TIM8_TRGO, NULL,

+};

+static const char *const valids4[] = {

• TIM2_TRGO, TIM3_TRGO, TIM4_TRGO, TIM8_TRGO, NULL,

+};

+static const char * const valids7[] = {

• TIM1_TRGO, TIM2_TRGO, TIM4_TRGO, TIM5_TRGO, NULL,

+};

+static const char * const valids8[] = {

• TIM2_TRGO, TIM3_TRGO, NULL,

+};

+static const char * const valids9[] = {

• TIM4_TRGO, TIM5_TRGO, NULL,

+};

+static const void *valids_table[] = {

• valids0,
• valids1,
• valids2,
• valids3,
• valids4,
• NULL,
• NULL,
• valids7,
• valids8,
• valids9,

+};

Same here.