This hardware block could at used at same time for PWM generation and IIO timers. PWM and IIO timer configuration are mixed in the same registers so we need a multi fonction driver to be able to share those registers.

version 4: - add a function to detect Auto Reload Register (ARR) size - rename the structure shared with other drivers

version 2: - rename driver "stm32-gptimer" to be align with SoC documentation - only keep one compatible - use of_platform_populate() instead of devm_mfd_add_devices()

Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com --- drivers/mfd/Kconfig | 11 ++++++ drivers/mfd/Makefile | 2 + drivers/mfd/stm32-gptimer.c | 82 +++++++++++++++++++++++++++++++++++++++ include/linux/mfd/stm32-gptimer.h | 63 ++++++++++++++++++++++++++++++ 4 files changed, 158 insertions(+) create mode 100644 drivers/mfd/stm32-gptimer.c create mode 100644 include/linux/mfd/stm32-gptimer.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index c6df644..a00f6b3 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -1607,6 +1607,17 @@ config MFD_STW481X in various ST Microelectronics and ST-Ericsson embedded Nomadik series.

+config MFD_STM32_GP_TIMER + tristate "Support for STM32 General Purpose Timer" + select MFD_CORE + select REGMAP + depends on ARCH_STM32 || COMPILE_TEST + depends on OF + help + Select this option to enable STM32 general purpose timer + driver used for PWM and IIO Timer. This driver allow to + share the registers between the others drivers. + menu "Multimedia Capabilities Port drivers" depends on ARCH_SA1100

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 9834e66..86353b9 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -211,3 +211,5 @@ obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o obj-$(CONFIG_MFD_MT6397) += mt6397-core.o

obj-$(CONFIG_MFD_ALTERA_A10SR) += altera-a10sr.o + +obj-$(CONFIG_MFD_STM32_GP_TIMER) += stm32-gptimer.o diff --git a/drivers/mfd/stm32-gptimer.c b/drivers/mfd/stm32-gptimer.c new file mode 100644 index 0000000..6747fcb --- /dev/null +++ b/drivers/mfd/stm32-gptimer.c @@ -0,0 +1,82 @@ +/* + * Copyright (C) STMicroelectronics 2016 + * + * Author: Benjamin Gaignard benjamin.gaignard@st.com + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/reset.h> + +#include <linux/mfd/stm32-gptimer.h> + +static const struct regmap_config stm32_gptimer_regmap_cfg = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = sizeof(u32), + .max_register = 0x400, +}; + +static u32 stm32_gptimer_get_arr_size(struct regmap *regmap) +{ + u32 max_arr; + + /* Only the available bits will be written so when readback + * we get the maximum value of auto reload register + */ + regmap_write(regmap, TIM_ARR, ~0L); + regmap_read(regmap, TIM_ARR, &max_arr); + regmap_write(regmap, TIM_ARR, 0x0); + + return max_arr; +} + +static int stm32_gptimer_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_gptimer *ddata; + struct resource *res; + void __iomem *mmio; + + ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + mmio = devm_ioremap_resource(dev, res); + if (IS_ERR(mmio)) + return PTR_ERR(mmio); + + ddata->regmap = devm_regmap_init_mmio_clk(dev, "clk_int", mmio, + &stm32_gptimer_regmap_cfg); + if (IS_ERR(ddata->regmap)) + return PTR_ERR(ddata->regmap); + + ddata->clk = devm_clk_get(dev, NULL); + if (IS_ERR(ddata->clk)) + return PTR_ERR(ddata->clk); + + ddata->max_arr = stm32_gptimer_get_arr_size(ddata->regmap); + + platform_set_drvdata(pdev, ddata); + + return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); +} + +static const struct of_device_id stm32_gptimer_of_match[] = { + { .compatible = "st,stm32-gptimer" }, +}; +MODULE_DEVICE_TABLE(of, stm32_gptimer_of_match); + +static struct platform_driver stm32_gptimer_driver = { + .probe = stm32_gptimer_probe, + .driver = { + .name = "stm32-gptimer", + .of_match_table = stm32_gptimer_of_match, + }, +}; +module_platform_driver(stm32_gptimer_driver); + +MODULE_DESCRIPTION("STMicroelectronics STM32 General Purpose Timer"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/mfd/stm32-gptimer.h b/include/linux/mfd/stm32-gptimer.h new file mode 100644 index 0000000..bf0a595 --- /dev/null +++ b/include/linux/mfd/stm32-gptimer.h @@ -0,0 +1,63 @@ +/* + * Copyright (C) STMicroelectronics 2016 + * + * Author: Benjamin Gaignard benjamin.gaignard@st.com + * License terms: GNU General Public License (GPL), version 2 + */ + +#ifndef _LINUX_STM32_GPTIMER_H_ +#define _LINUX_STM32_GPTIMER_H_ + +#include <linux/clk.h> +#include <linux/regmap.h> + +#define TIM_CR1 0x00 /* Control Register 1 */ +#define TIM_CR2 0x04 /* Control Register 2 */ +#define TIM_SMCR 0x08 /* Slave mode control reg */ +#define TIM_DIER 0x0C /* DMA/interrupt register */ +#define TIM_SR 0x10 /* Status register */ +#define TIM_EGR 0x14 /* Event Generation Reg */ +#define TIM_CCMR1 0x18 /* Capt/Comp 1 Mode Reg */ +#define TIM_CCMR2 0x1C /* Capt/Comp 2 Mode Reg */ +#define TIM_CCER 0x20 /* Capt/Comp Enable Reg */ +#define TIM_PSC 0x28 /* Prescaler */ +#define TIM_ARR 0x2c /* Auto-Reload Register */ +#define TIM_CCR1 0x34 /* Capt/Comp Register 1 */ +#define TIM_CCR2 0x38 /* Capt/Comp Register 2 */ +#define TIM_CCR3 0x3C /* Capt/Comp Register 3 */ +#define TIM_CCR4 0x40 /* Capt/Comp Register 4 */ +#define TIM_BDTR 0x44 /* Break and Dead-Time Reg */ + +#define TIM_CR1_CEN BIT(0) /* Counter Enable */ +#define TIM_CR1_ARPE BIT(7) /* Auto-reload Preload Ena */ +#define TIM_CR2_MMS (BIT(4) | BIT(5) | BIT(6)) /* Master mode selection */ +#define TIM_SMCR_SMS (BIT(0) | BIT(1) | BIT(2)) /* Slave mode selection */ +#define TIM_SMCR_TS (BIT(4) | BIT(5) | BIT(6)) /* Trigger selection */ +#define TIM_DIER_UIE BIT(0) /* Update interrupt */ +#define TIM_SR_UIF BIT(0) /* Update interrupt flag */ +#define TIM_EGR_UG BIT(0) /* Update Generation */ +#define TIM_CCMR_PE BIT(3) /* Channel Preload Enable */ +#define TIM_CCMR_M1 (BIT(6) | BIT(5)) /* Channel PWM Mode 1 */ +#define TIM_CCER_CC1E BIT(0) /* Capt/Comp 1 out Ena */ +#define TIM_CCER_CC1P BIT(1) /* Capt/Comp 1 Polarity */ +#define TIM_CCER_CC1NE BIT(2) /* Capt/Comp 1N out Ena */ +#define TIM_CCER_CC1NP BIT(3) /* Capt/Comp 1N Polarity */ +#define TIM_CCER_CC2E BIT(4) /* Capt/Comp 2 out Ena */ +#define TIM_CCER_CC3E BIT(8) /* Capt/Comp 3 out Ena */ +#define TIM_CCER_CC4E BIT(12) /* Capt/Comp 4 out Ena */ +#define TIM_CCER_CCXE (BIT(0) | BIT(4) | BIT(8) | BIT(12)) +#define TIM_BDTR_BKE BIT(12) /* Break input enable */ +#define TIM_BDTR_BKP BIT(13) /* Break input polarity */ +#define TIM_BDTR_AOE BIT(14) /* Automatic Output Enable */ +#define TIM_BDTR_MOE BIT(15) /* Main Output Enable */ + +#define MAX_TIM_PSC 0xFFFF +#define TIM_CR2_MMS_SHIFT 4 +#define TIM_SMCR_TS_SHIFT 4 + +struct stm32_gptimer { + struct clk *clk; + struct regmap *regmap; + u32 max_arr; +}; +#endif

This driver adds support for PWM driver on STM32 platform. The SoC have multiple instances of the hardware IP and each of them could have small differences: number of channels, complementary output, auto reload register size...

version 4: - detect at probe time hardware capabilities - fix comments done on v2 and v3 - use PWM atomic ops

version 2: - only keep one comptatible - use DT parameters to discover hardware block configuration

Signed-off-by: Benjamin Gaignard benjamin.gaignard@st.com --- drivers/pwm/Kconfig | 11 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-stm32.c | 363 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 375 insertions(+) create mode 100644 drivers/pwm/pwm-stm32.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index bf01288..95c9f04 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -388,6 +388,17 @@ config PWM_STI To compile this driver as a module, choose M here: the module will be called pwm-sti.

+config PWM_STM32 + bool "STMicroelectronics STM32 PWM" + depends on ARCH_STM32 || COMPILE_TEST + depends on OF + depends on MFD_STM32_GP_TIMER + help + Generic PWM framework driver for STM32 SoCs. + + To compile this driver as a module, choose M here: the module + will be called pwm-stm32. + config PWM_STMPE bool "STMPE expander PWM export" depends on MFD_STMPE diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 1194c54..5aa9308 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -37,6 +37,7 @@ obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o obj-$(CONFIG_PWM_SPEAR) += pwm-spear.o obj-$(CONFIG_PWM_STI) += pwm-sti.o +obj-$(CONFIG_PWM_STM32) += pwm-stm32.o obj-$(CONFIG_PWM_STMPE) += pwm-stmpe.o obj-$(CONFIG_PWM_SUN4I) += pwm-sun4i.o obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c new file mode 100644 index 0000000..319fd77 --- /dev/null +++ b/drivers/pwm/pwm-stm32.c @@ -0,0 +1,363 @@ +/* + * Copyright (C) STMicroelectronics 2016 + * + * Author: Gerald Baeza gerald.baeza@st.com + * License terms: GNU General Public License (GPL), version 2 + * + * Inspired by timer-stm32.c from Maxime Coquelin + * pwm-atmel.c from Bo Shen + */ + +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/of.h> + +#include <linux/mfd/stm32-gptimer.h> + +#define CCMR_CHANNEL_SHIFT 8 +#define CCMR_CHANNEL_MASK 0xFF + +struct stm32_pwm { + struct pwm_chip chip; + struct device *dev; + struct clk *clk; + struct regmap *regmap; + unsigned int caps; + unsigned int npwm; + u32 breakinput_polarity; + u32 max_arr; + bool have_complementary_output; + bool have_breakinput; + bool use_breakinput; +}; + +#define to_stm32_pwm_dev(x) container_of(chip, struct stm32_pwm, chip) + +static u32 active_channels(struct stm32_pwm *dev) +{ + u32 ccer; + + regmap_read(dev->regmap, TIM_CCER, &ccer); + + return ccer & TIM_CCER_CCXE; +} + +static int write_ccrx(struct stm32_pwm *dev, struct pwm_device *pwm, + u32 value) +{ + switch (pwm->hwpwm) { + case 0: + return regmap_write(dev->regmap, TIM_CCR1, value); + case 1: + return regmap_write(dev->regmap, TIM_CCR2, value); + case 2: + return regmap_write(dev->regmap, TIM_CCR3, value); + case 3: + return regmap_write(dev->regmap, TIM_CCR4, value); + } + return -EINVAL; +} + +static int stm32_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct stm32_pwm *priv = to_stm32_pwm_dev(chip); + unsigned long long prd, div, dty; + unsigned int prescaler = 0; + u32 ccmr, mask, shift, bdtr; + + /* Period and prescaler values depends on clock rate */ + div = (unsigned long long)clk_get_rate(priv->clk) * period_ns; + + do_div(div, NSEC_PER_SEC); + prd = div; + + while (div > priv->max_arr) { + prescaler++; + div = prd; + do_div(div, (prescaler + 1)); + } + + prd = div; + + if (prescaler > MAX_TIM_PSC) { + dev_err(chip->dev, "prescaler exceeds the maximum value\n"); + return -EINVAL; + } + + /* + * All channels share the same prescaler and counter so when two + * channels are active at the same we can't change them + */ + if (active_channels(priv) & ~(1 << pwm->hwpwm * 4)) { + u32 psc, arr; + + regmap_read(priv->regmap, TIM_PSC, &psc); + regmap_read(priv->regmap, TIM_ARR, &arr); + + if ((psc != prescaler) || (arr != prd - 1)) + return -EBUSY; + } + + regmap_write(priv->regmap, TIM_PSC, prescaler); + regmap_write(priv->regmap, TIM_ARR, prd - 1); + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE); + + /* Calculate the duty cycles */ + dty = prd * duty_ns; + do_div(dty, period_ns); + + write_ccrx(priv, pwm, dty); + + /* Configure output mode */ + shift = (pwm->hwpwm & 0x1) * CCMR_CHANNEL_SHIFT; + ccmr = (TIM_CCMR_PE | TIM_CCMR_M1) << shift; + mask = CCMR_CHANNEL_MASK << shift; + + if (pwm->hwpwm < 2) + regmap_update_bits(priv->regmap, TIM_CCMR1, mask, ccmr); + else + regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr); + + if (!priv->have_breakinput) + return 0; + + bdtr = TIM_BDTR_MOE | TIM_BDTR_AOE; + + if (priv->use_breakinput) + bdtr |= TIM_BDTR_BKE; + + if (priv->breakinput_polarity) + bdtr |= TIM_BDTR_BKP; + + regmap_update_bits(priv->regmap, TIM_BDTR, + TIM_BDTR_MOE | TIM_BDTR_AOE | + TIM_BDTR_BKP | TIM_BDTR_BKE, + bdtr); + + return 0; +} + +static int stm32_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + u32 mask; + struct stm32_pwm *priv = to_stm32_pwm_dev(chip); + + mask = TIM_CCER_CC1P << (pwm->hwpwm * 4); + if (priv->have_complementary_output) + mask |= TIM_CCER_CC1NP << (pwm->hwpwm * 4); + + regmap_update_bits(priv->regmap, TIM_CCER, mask, + polarity == PWM_POLARITY_NORMAL ? 0 : mask); + + return 0; +} + +static int stm32_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + u32 mask; + struct stm32_pwm *priv = to_stm32_pwm_dev(chip); + + clk_enable(priv->clk); + + /* Enable channel */ + mask = TIM_CCER_CC1E << (pwm->hwpwm * 4); + if (priv->have_complementary_output) + mask |= TIM_CCER_CC1NE << (pwm->hwpwm * 4); + + regmap_update_bits(priv->regmap, TIM_CCER, mask, mask); + + /* Make sure that registers are updated */ + regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG); + + /* Enable controller */ + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN); + + return 0; +} + +static void stm32_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + u32 mask; + struct stm32_pwm *priv = to_stm32_pwm_dev(chip); + + /* Disable channel */ + mask = TIM_CCER_CC1E << (pwm->hwpwm * 4); + if (priv->have_complementary_output) + mask |= TIM_CCER_CC1NE << (pwm->hwpwm * 4); + + regmap_update_bits(priv->regmap, TIM_CCER, mask, 0); + + /* When all channels are disabled, we can disable the controller */ + if (!active_channels(priv)) + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0); + + clk_disable(priv->clk); +} + +static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct pwm_state curstate; + bool enabled; + int ret; + + pwm_get_state(pwm, &curstate); + enabled = curstate.enabled; + + if (enabled && !state->enabled) { + stm32_pwm_disable(chip, pwm); + return 0; + } + + if (state->polarity != curstate.polarity && enabled) + stm32_pwm_set_polarity(chip, pwm, state->polarity); + + ret = stm32_pwm_config(chip, pwm, state->duty_cycle, state->period); + if (ret) + return ret; + + if (!enabled && state->enabled) + ret = stm32_pwm_enable(chip, pwm); + + return ret; +} + +static const struct pwm_ops stm32pwm_ops = { + .owner = THIS_MODULE, + .apply = stm32_pwm_apply, +}; + +static bool stm32_pwm_detect_breakinput(struct regmap *regmap) +{ + u32 bdtr; + + /* + * If breakinput enable bit doesn't exist writing 1 will have no + * effect so we can detect it. + */ + regmap_update_bits(regmap, TIM_BDTR, TIM_BDTR_BKE, TIM_BDTR_BKE); + regmap_read(regmap, TIM_BDTR, &bdtr); + regmap_update_bits(regmap, TIM_BDTR, TIM_BDTR_BKE, 0); + + return (bdtr != 0); +} + +static bool stm32_pwm_detect_complementary(struct regmap *regmap) +{ + u32 ccer; + + /* + * If complementary bit doesn't exist writing 1 will have no + * effect so we can detect it. + */ + regmap_update_bits(regmap, TIM_CCER, TIM_CCER_CC1NE, TIM_CCER_CC1NE); + regmap_read(regmap, TIM_CCER, &ccer); + regmap_update_bits(regmap, TIM_CCER, TIM_CCER_CCXE, 0); + + return (ccer != 0); +} + +static int stm32_pwm_detect_channels(struct regmap *regmap) +{ + int channels = 0; + u32 ccer; + + /* + * If channels enable bits don't exist writing 1 will have no + * effect so we can detect and count them. + */ + regmap_update_bits(regmap, TIM_CCER, TIM_CCER_CCXE, TIM_CCER_CCXE); + regmap_read(regmap, TIM_CCER, &ccer); + regmap_update_bits(regmap, TIM_CCER, TIM_CCER_CCXE, 0); + + if (ccer & TIM_CCER_CC1E) + channels++; + + if (ccer & TIM_CCER_CC2E) + channels++; + + if (ccer & TIM_CCER_CC3E) + channels++; + + if (ccer & TIM_CCER_CC4E) + channels++; + + return channels; +} + +static int stm32_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct stm32_gptimer *ddata = dev_get_drvdata(pdev->dev.parent); + struct stm32_pwm *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = ddata->regmap; + priv->clk = ddata->clk; + priv->max_arr = ddata->max_arr; + + if (!priv->regmap || !priv->clk) + return -EINVAL; + + priv->have_breakinput = stm32_pwm_detect_breakinput(priv->regmap); + priv->have_complementary_output = + stm32_pwm_detect_complementary(priv->regmap); + priv->npwm = stm32_pwm_detect_channels(priv->regmap); + + if (!of_property_read_u32(np, "st,breakinput-polarity", + &priv->breakinput_polarity)) + priv->use_breakinput = true; + + priv->chip.base = -1; + priv->chip.dev = dev; + priv->chip.ops = &stm32pwm_ops; + priv->chip.npwm = priv->npwm; + + ret = pwmchip_add(&priv->chip); + if (ret < 0) + return ret; + + platform_set_drvdata(pdev, priv); + + return 0; +} + +static int stm32_pwm_remove(struct platform_device *pdev) +{ + struct stm32_pwm *priv = platform_get_drvdata(pdev); + unsigned int i; + + for (i = 0; i < priv->npwm; i++) + pwm_disable(&priv->chip.pwms[i]); + + pwmchip_remove(&priv->chip); + + return 0; +} + +static const struct of_device_id stm32_pwm_of_match[] = { + { .compatible = "st,stm32-pwm", } +}; +MODULE_DEVICE_TABLE(of, stm32_pwm_of_match); + +static struct platform_driver stm32_pwm_driver = { + .probe = stm32_pwm_probe, + .remove = stm32_pwm_remove, + .driver = { + .name = "stm32-pwm", + .of_match_table = stm32_pwm_of_match, + }, +}; +module_platform_driver(stm32_pwm_driver); + +MODULE_ALIAS("platform: stm32-pwm"); +MODULE_DESCRIPTION("STMicroelectronics STM32 PWM driver"); +MODULE_LICENSE("GPL v2");

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, +}; + +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, +}; + +struct stm32_timer_trigger { + struct device *dev; + struct regmap *regmap; + struct clk *clk; + u32 max_arr; + const void *triggers; + const void *valids; +}; + +static int stm32_timer_start(struct stm32_timer_trigger *priv, + unsigned int frequency) +{ + unsigned long long prd, div; + int prescaler = 0; + u32 ccer, cr1; + + /* Period and prescaler values depends of clock rate */ + div = (unsigned long long)clk_get_rate(priv->clk); + + do_div(div, frequency); + + prd = div; + + /* + * Increase prescaler value until we get a result that fit + * with auto reload register maximum value. + */ + while (div > priv->max_arr) { + prescaler++; + div = prd; + do_div(div, (prescaler + 1)); + } + prd = div; + + if (prescaler > MAX_TIM_PSC) { + dev_err(priv->dev, "prescaler exceeds the maximum value\n"); + return -EINVAL; + } + + /* Check if nobody else use the timer */ + regmap_read(priv->regmap, TIM_CCER, &ccer); + if (ccer & TIM_CCER_CCXE) + return -EBUSY; + + regmap_read(priv->regmap, TIM_CR1, &cr1); + if (!(cr1 & TIM_CR1_CEN)) + clk_enable(priv->clk); + + regmap_write(priv->regmap, TIM_PSC, prescaler); + regmap_write(priv->regmap, TIM_ARR, prd - 1); + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE); + + /* Force master mode to update mode */ + regmap_update_bits(priv->regmap, TIM_CR2, TIM_CR2_MMS, 0x20); + + /* Make sure that registers are updated */ + regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG); + + /* Enable controller */ + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, TIM_CR1_CEN); + + return 0; +} + +static void stm32_timer_stop(struct stm32_timer_trigger *priv) +{ + u32 ccer, cr1; + + regmap_read(priv->regmap, TIM_CCER, &ccer); + if (ccer & TIM_CCER_CCXE) + return; + + regmap_read(priv->regmap, TIM_CR1, &cr1); + if (cr1 & TIM_CR1_CEN) + clk_disable(priv->clk); + + /* Stop timer */ + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0); + regmap_write(priv->regmap, TIM_PSC, 0); + regmap_write(priv->regmap, TIM_ARR, 0); +} + +static ssize_t stm32_tt_store_frequency(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_trigger *trig = to_iio_trigger(dev); + struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig); + unsigned int freq; + int ret; + + ret = kstrtouint(buf, 10, &freq); + if (ret) + return ret; + + if (freq == 0) { + stm32_timer_stop(priv); + } else { + ret = stm32_timer_start(priv, freq); + if (ret) + return ret; + } + + return len; +} + +static ssize_t stm32_tt_read_frequency(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iio_trigger *trig = to_iio_trigger(dev); + struct stm32_timer_trigger *priv = iio_trigger_get_drvdata(trig); + u32 psc, arr, cr1; + unsigned long long freq = 0; + + regmap_read(priv->regmap, TIM_CR1, &cr1); + regmap_read(priv->regmap, TIM_PSC, &psc); + regmap_read(priv->regmap, TIM_ARR, &arr); + + if (psc && arr && (cr1 & TIM_CR1_CEN)) { + freq = (unsigned long long)clk_get_rate(priv->clk); + do_div(freq, psc); + do_div(freq, arr); + } + + return sprintf(buf, "%d\n", (unsigned int)freq); +} + +static IIO_DEV_ATTR_SAMP_FREQ(0660, + stm32_tt_read_frequency, + stm32_tt_store_frequency); + +static struct attribute *stm32_trigger_attrs[] = { + &iio_dev_attr_sampling_frequency.dev_attr.attr, + NULL, +}; + +static const struct attribute_group stm32_trigger_attr_group = { + .attrs = stm32_trigger_attrs, +}; + +static const struct attribute_group *stm32_trigger_attr_groups[] = { + &stm32_trigger_attr_group, + NULL, +}; + +static char *master_mode_table[] = { + "reset", + "enable", + "update", + "compare_pulse", + "OC1REF", + "OC2REF", + "OC3REF", + "OC4REF" +}; + +static ssize_t stm32_tt_show_master_mode(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct stm32_timer_trigger *priv = iio_priv(indio_dev); + u32 cr2; + + regmap_read(priv->regmap, TIM_CR2, &cr2); + cr2 = (cr2 & TIM_CR2_MMS) >> TIM_CR2_MMS_SHIFT; + + return snprintf(buf, PAGE_SIZE, "%s\n", master_mode_table[cr2]); +} + +static ssize_t stm32_tt_store_master_mode(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct stm32_timer_trigger *priv = iio_priv(indio_dev); + int i; + + for (i = 0; i < ARRAY_SIZE(master_mode_table); i++) { + if (!strncmp(master_mode_table[i], buf, + strlen(master_mode_table[i]))) { + regmap_update_bits(priv->regmap, TIM_CR2, + TIM_CR2_MMS, i << TIM_CR2_MMS_SHIFT); + return len; + } + } + + return -EINVAL; +} + +static IIO_CONST_ATTR(master_mode_available, + "reset enable update compare_pulse OC1REF OC2REF OC3REF OC4REF"); + +static IIO_DEVICE_ATTR(master_mode, 0660, + stm32_tt_show_master_mode, + stm32_tt_store_master_mode, + 0); + +static char *slave_mode_table[] = { + "disabled", + "encoder_1", + "encoder_2", + "encoder_3", + "reset", + "gated", + "trigger", + "external_clock", +}; + +static ssize_t stm32_tt_show_slave_mode(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct stm32_timer_trigger *priv = iio_priv(indio_dev); + u32 smcr; + + regmap_read(priv->regmap, TIM_SMCR, &smcr); + smcr &= TIM_SMCR_SMS; + + return snprintf(buf, PAGE_SIZE, "%s\n", slave_mode_table[smcr]); +} + +static ssize_t stm32_tt_store_slave_mode(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + struct stm32_timer_trigger *priv = iio_priv(indio_dev); + int i; + + for (i = 0; i < ARRAY_SIZE(slave_mode_table); i++) { + if (!strncmp(slave_mode_table[i], buf, + strlen(slave_mode_table[i]))) { + regmap_update_bits(priv->regmap, + TIM_SMCR, TIM_SMCR_SMS, i); + return len; + } + } + + return -EINVAL; +} + +static IIO_CONST_ATTR(slave_mode_available, +"disabled encoder_1 encoder_2 encoder_3 reset gated trigger external_clock"); + +static IIO_DEVICE_ATTR(slave_mode, 0660, + stm32_tt_show_slave_mode, + stm32_tt_store_slave_mode, + 0); + +static struct attribute *stm32_timer_attrs[] = { + &iio_dev_attr_master_mode.dev_attr.attr, + &iio_const_attr_master_mode_available.dev_attr.attr, + &iio_dev_attr_slave_mode.dev_attr.attr, + &iio_const_attr_slave_mode_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group stm32_timer_attr_group = { + .attrs = stm32_timer_attrs, +}; + +static const struct iio_trigger_ops timer_trigger_ops = { + .owner = THIS_MODULE, +}; + +static int stm32_setup_iio_triggers(struct stm32_timer_trigger *priv) +{ + int ret; + const char * const *cur = priv->triggers; + + while (cur && *cur) { + struct iio_trigger *trig; + + trig = devm_iio_trigger_alloc(priv->dev, "%s", *cur); + if (!trig) + return -ENOMEM; + + trig->dev.parent = priv->dev->parent; + trig->ops = &timer_trigger_ops; + trig->dev.groups = stm32_trigger_attr_groups; + iio_trigger_set_drvdata(trig, priv); + + ret = devm_iio_trigger_register(priv->dev, trig); + if (ret) + return ret; + cur++; + } + + return 0; +} + +/** + * is_stm32_timer_trigger + * @trig: trigger to be checked + * + * return true if the trigger is a valid stm32 iio timer trigger + * either return false + */ +bool is_stm32_timer_trigger(struct iio_trigger *trig) +{ + return (trig->ops == &timer_trigger_ops); +} +EXPORT_SYMBOL(is_stm32_timer_trigger); + +static int stm32_validate_trigger(struct iio_dev *indio_dev, + struct iio_trigger *trig) +{ + struct stm32_timer_trigger *priv = iio_priv(indio_dev); + const char * const *cur = priv->valids; + unsigned int i = 0; + + if (!is_stm32_timer_trigger(trig)) + return -EINVAL; + + while (cur && *cur) { + if (!strncmp(trig->name, *cur, strlen(trig->name))) { + regmap_update_bits(priv->regmap, + TIM_SMCR, TIM_SMCR_TS, + i << TIM_SMCR_TS_SHIFT); + return 0; + } + cur++; + i++; + } + + return -EINVAL; +} + +static const struct iio_info stm32_trigger_info = { + .driver_module = THIS_MODULE, + .validate_trigger = stm32_validate_trigger, + .attrs = &stm32_timer_attr_group, +}; + +static struct stm32_timer_trigger *stm32_setup_iio_device(struct device *dev) +{ + struct iio_dev *indio_dev; + int ret; + + indio_dev = devm_iio_device_alloc(dev, + sizeof(struct stm32_timer_trigger)); + if (!indio_dev) + return NULL; + + indio_dev->name = dev_name(dev); + indio_dev->dev.parent = dev; + indio_dev->info = &stm32_trigger_info; + indio_dev->modes = INDIO_EVENT_TRIGGERED; + indio_dev->num_channels = 0; + indio_dev->dev.of_node = dev->of_node; + + ret = devm_iio_device_register(dev, indio_dev); + if (ret) + return NULL; + + return iio_priv(indio_dev); +} + +static int stm32_timer_trigger_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct stm32_timer_trigger *priv; + struct stm32_gptimer *ddata = dev_get_drvdata(pdev->dev.parent); + unsigned int index; + int ret; + + if (of_property_read_u32(dev->of_node, "reg", &index)) + return -EINVAL; + + if (index >= ARRAY_SIZE(triggers_table)) + return -EINVAL; + + priv = stm32_setup_iio_device(dev); + if (!priv) + return -ENOMEM; + + priv->dev = dev; + priv->regmap = ddata->regmap; + priv->clk = ddata->clk; + priv->max_arr = ddata->max_arr; + priv->triggers = triggers_table[index]; + priv->valids = valids_table[index]; + + ret = stm32_setup_iio_triggers(priv); + if (ret) + return ret; + + platform_set_drvdata(pdev, priv); + + return 0; +} + +static const struct of_device_id stm32_trig_of_match[] = { + { .compatible = "st,stm32-timer-trigger" } +}; +MODULE_DEVICE_TABLE(of, stm32_trig_of_match); + +static struct platform_driver stm32_timer_trigger_driver = { + .probe = stm32_timer_trigger_probe, + .driver = { + .name = "stm32-timer-trigger", + .of_match_table = stm32_trig_of_match, + }, +}; +module_platform_driver(stm32_timer_trigger_driver); + +MODULE_ALIAS("platform: stm32-timer-trigger"); +MODULE_DESCRIPTION("STMicroelectronics STM32 Timer Trigger driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig index 809b2e7..f2af4fe 100644 --- a/drivers/iio/trigger/Kconfig +++ b/drivers/iio/trigger/Kconfig @@ -46,5 +46,4 @@ config IIO_SYSFS_TRIGGER

To compile this driver as a module, choose M here: the module will be called iio-trig-sysfs. - endmenu diff --git a/include/linux/iio/timer/stm32-timer-trigger.h b/include/linux/iio/timer/stm32-timer-trigger.h new file mode 100644 index 0000000..06bbaea --- /dev/null +++ b/include/linux/iio/timer/stm32-timer-trigger.h @@ -0,0 +1,61 @@ +/* + * Copyright (C) STMicroelectronics 2016 + * + * Author: Benjamin Gaignard benjamin.gaignard@st.com + * License terms: GNU General Public License (GPL), version 2 + */ + +#ifndef _STM32_TIMER_TRIGGER_H_ +#define _STM32_TIMER_TRIGGER_H_ + +#define TIM1_TRGO "tim1_trgo" +#define TIM1_CH1 "tim1_ch1" +#define TIM1_CH2 "tim1_ch2" +#define TIM1_CH3 "tim1_ch3" +#define TIM1_CH4 "tim1_ch4" + +#define TIM2_TRGO "tim2_trgo" +#define TIM2_CH1 "tim2_ch1" +#define TIM2_CH2 "tim2_ch2" +#define TIM2_CH3 "tim2_ch3" +#define TIM2_CH4 "tim2_ch4" + +#define TIM3_TRGO "tim3_trgo" +#define TIM3_CH1 "tim3_ch1" +#define TIM3_CH2 "tim3_ch2" +#define TIM3_CH3 "tim3_ch3" +#define TIM3_CH4 "tim3_ch4" + +#define TIM4_TRGO "tim4_trgo" +#define TIM4_CH1 "tim4_ch1" +#define TIM4_CH2 "tim4_ch2" +#define TIM4_CH3 "tim4_ch3" +#define TIM4_CH4 "tim4_ch4" + +#define TIM5_TRGO "tim5_trgo" +#define TIM5_CH1 "tim5_ch1" +#define TIM5_CH2 "tim5_ch2" +#define TIM5_CH3 "tim5_ch3" +#define TIM5_CH4 "tim5_ch4" + +#define TIM6_TRGO "tim6_trgo" + +#define TIM7_TRGO "tim7_trgo" + +#define TIM8_TRGO "tim8_trgo" +#define TIM8_CH1 "tim8_ch1" +#define TIM8_CH2 "tim8_ch2" +#define TIM8_CH3 "tim8_ch3" +#define TIM8_CH4 "tim8_ch4" + +#define TIM9_TRGO "tim9_trgo" +#define TIM9_CH1 "tim9_ch1" +#define TIM9_CH2 "tim9_ch2" + +#define TIM12_TRGO "tim12_trgo" +#define TIM12_CH1 "tim12_ch1" +#define TIM12_CH2 "tim12_ch2" + +bool is_stm32_timer_trigger(struct iio_trigger *trig); + +#endif