From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932685AbeCISoF (ORCPT ); Fri, 9 Mar 2018 13:44:05 -0500 Received: from mail-yw0-f196.google.com ([209.85.161.196]:45611 "EHLO mail-yw0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932195AbeCISoC (ORCPT ); Fri, 9 Mar 2018 13:44:02 -0500 X-Google-Smtp-Source: AG47ELvfgp7SbcVKBe0kuBZz6Ev7B+Se0HwBTq0TGcNgRG5G7qmyzZkoVgvhbROLdijybaQgM31+gA== From: William Breathitt Gray To: jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net Cc: benjamin.gaignard@st.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, William Breathitt Gray Subject: [PATCH v5 8/8] Counter: Add STM32 Timer quadrature encoder Date: Fri, 9 Mar 2018 13:43:55 -0500 Message-Id: <09612a4089226bbe564bfab9053a0293cdfb5f0c.1520614431.git.vilhelm.gray@gmail.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Benjamin Gaignard Implement counter part of the STM32 timer hardware block by using counter API. Hardware only support X2 and X4 quadrature modes. A Preset value can to set to define the maximum value reachable by the counter. Signed-off-by: Benjamin Gaignard Signed-off-by: William Breathitt Gray --- drivers/counter/Kconfig | 10 ++ drivers/counter/Makefile | 1 + drivers/counter/stm32-timer-cnt.c | 356 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 367 insertions(+) create mode 100644 drivers/counter/stm32-timer-cnt.c diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig index 0b28d3ff524b..d758279081ac 100644 --- a/drivers/counter/Kconfig +++ b/drivers/counter/Kconfig @@ -35,6 +35,16 @@ config 104_QUAD_8 The base port addresses for the devices may be configured via the base array module parameter. +config STM32_TIMER_CNT + tristate "STM32 Timer encoder counter driver" + depends on MFD_STM32_TIMERS || COMPILE_TEST + help + Select this option to enable STM32 Timer quadrature encoder + and counter driver. + + To compile this driver as a module, choose M here: the + module will be called stm32-timer-cnt. + config STM32_LPTIMER_CNT tristate "STM32 LP Timer encoder counter driver" depends on (MFD_STM32_LPTIMER || COMPILE_TEST) && IIO diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile index d721a40aa4a2..9c037d7d1ed6 100644 --- a/drivers/counter/Makefile +++ b/drivers/counter/Makefile @@ -8,4 +8,5 @@ obj-$(CONFIG_COUNTER) += counter.o counter-y := generic-counter.o obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o +obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c new file mode 100644 index 000000000000..14085615e880 --- /dev/null +++ b/drivers/counter/stm32-timer-cnt.c @@ -0,0 +1,356 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * STM32 Timer Encoder and Counter driver + * + * Copyright (C) STMicroelectronics 2018 + * + * Author: Benjamin Gaignard + * + */ +#include +#include +#include +#include +#include +#include + +#define TIM_CCMR_CCXS (BIT(8) | BIT(0)) +#define TIM_CCMR_MASK (TIM_CCMR_CC1S | TIM_CCMR_CC2S | \ + TIM_CCMR_IC1F | TIM_CCMR_IC2F) +#define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \ + TIM_CCER_CC2P | TIM_CCER_CC2NP) + +struct stm32_timer_cnt { + struct counter_device counter; + struct regmap *regmap; + struct clk *clk; + u32 preset; +}; + +enum stm32_count_function { + STM32_COUNT_FUNCTION_QUADRATURE_X2, + STM32_COUNT_FUNCTION_QUADRATURE_X4, +}; + +static enum count_function stm32_count_functions[] = { + [STM32_COUNT_FUNCTION_QUADRATURE_X2] = COUNT_FUNCTION_QUADRATURE_X2, + [STM32_COUNT_FUNCTION_QUADRATURE_X4] = COUNT_FUNCTION_QUADRATURE_X4 +}; + +static int stm32_count_read(struct counter_device *counter, + struct counter_count *count, + struct count_read_value *val) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 cnt; + + regmap_read(priv->regmap, TIM_CNT, &cnt); + set_count_read_value(val, COUNT_POSITION_UNSIGNED, &cnt); + + return 0; +} + +static int stm32_count_write(struct counter_device *counter, + struct counter_count *count, + struct count_write_value *val) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 cnt; + int err; + + err = get_count_write_value(&cnt, COUNT_POSITION_UNSIGNED, val); + if (err) + return err; + + if (cnt > priv->preset) + return -EINVAL; + + return regmap_write(priv->regmap, TIM_CNT, cnt); +} + +static int stm32_count_function_get(struct counter_device *counter, + struct counter_count *count, + size_t *function) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 smcr; + + regmap_read(priv->regmap, TIM_SMCR, &smcr); + + switch (smcr & TIM_SMCR_SMS) { + case 1: + *function = STM32_COUNT_FUNCTION_QUADRATURE_X2; + return 0; + case 3: + *function = STM32_COUNT_FUNCTION_QUADRATURE_X4; + return 0; + } + + return -EINVAL; +} + +static int stm32_count_function_set(struct counter_device *counter, + struct counter_count *count, + size_t function) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 cr1, sms; + + switch (function) { + case STM32_COUNT_FUNCTION_QUADRATURE_X2: + sms = 1; + break; + case STM32_COUNT_FUNCTION_QUADRATURE_X4: + sms = 3; + break; + default: + return -EINVAL; + } + + /* Store enable status */ + regmap_read(priv->regmap, TIM_CR1, &cr1); + + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0); + + /* TIMx_ARR register shouldn't be buffered (ARPE=0) */ + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0); + regmap_write(priv->regmap, TIM_ARR, priv->preset); + + regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms); + + /* Make sure that registers are updated */ + regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG); + + /* Restore the enable status */ + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, cr1); + + return 0; +} + +static ssize_t stm32_count_direction_read(struct counter_device *counter, + struct counter_count *count, + void *private, char *buf) +{ + struct stm32_timer_cnt *const priv = counter->priv; + const char *direction; + u32 cr1; + + regmap_read(priv->regmap, TIM_CR1, &cr1); + direction = (cr1 & TIM_CR1_DIR) ? "backward" : "forward"; + + return scnprintf(buf, PAGE_SIZE, "%s\n", direction); +} + +static ssize_t stm32_count_preset_read(struct counter_device *counter, + struct counter_count *count, + void *private, char *buf) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 arr; + + regmap_read(priv->regmap, TIM_ARR, &arr); + + return snprintf(buf, PAGE_SIZE, "%u\n", arr); +} + +static ssize_t stm32_count_preset_write(struct counter_device *counter, + struct counter_count *count, + void *private, + const char *buf, size_t len) +{ + struct stm32_timer_cnt *const priv = counter->priv; + unsigned int preset; + int ret; + + ret = kstrtouint(buf, 0, &preset); + if (ret) + return ret; + + /* TIMx_ARR register shouldn't be buffered (ARPE=0) */ + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0); + regmap_write(priv->regmap, TIM_ARR, preset); + + priv->preset = preset; + return len; +} + +static ssize_t stm32_count_enable_read(struct counter_device *counter, + struct counter_count *count, + void *private, char *buf) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 cr1; + + regmap_read(priv->regmap, TIM_CR1, &cr1); + + return scnprintf(buf, PAGE_SIZE, "%d\n", (bool)(cr1 & TIM_CR1_CEN)); +} + +static ssize_t stm32_count_enable_write(struct counter_device *counter, + struct counter_count *count, + void *private, + const char *buf, size_t len) +{ + struct stm32_timer_cnt *const priv = counter->priv; + int err; + u32 cr1; + bool enable; + + err = kstrtobool(buf, &enable); + if (err) + return err; + + if (enable) { + regmap_read(priv->regmap, TIM_CR1, &cr1); + if (!(cr1 & TIM_CR1_CEN)) + clk_enable(priv->clk); + + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, + TIM_CR1_CEN); + } else { + regmap_read(priv->regmap, TIM_CR1, &cr1); + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0); + if (cr1 & TIM_CR1_CEN) + clk_disable(priv->clk); + } + + return len; +} + +static const struct counter_count_ext stm32_count_ext[] = { + { + .name = "direction", + .read = stm32_count_direction_read, + }, + { + .name = "enable", + .read = stm32_count_enable_read, + .write = stm32_count_enable_write + }, + { + .name = "preset", + .read = stm32_count_preset_read, + .write = stm32_count_preset_write + }, +}; + +enum stm32_synapse_action { + STM32_SYNAPSE_ACTION_RISING_EDGE = 0, + STM32_SYNAPSE_ACTION_BOTH_EDGES +}; + +static enum synapse_action stm32_synapse_actions[] = { + [STM32_SYNAPSE_ACTION_RISING_EDGE] = SYNAPSE_ACTION_RISING_EDGE, + [STM32_SYNAPSE_ACTION_BOTH_EDGES] = SYNAPSE_ACTION_BOTH_EDGES +}; + +static int stm32_action_get(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + size_t *action) +{ + struct stm32_timer_cnt *const priv = counter->priv; + u32 smcr; + + regmap_read(priv->regmap, TIM_SMCR, &smcr); + + switch (smcr & TIM_SMCR_SMS) { + case 1: + *action = STM32_SYNAPSE_ACTION_RISING_EDGE; + return 0; + case 3: + *action = STM32_SYNAPSE_ACTION_BOTH_EDGES; + return 0; + } + + return -EINVAL; +} + +static struct counter_signal stm32_signals[] = { + { + .id = 0, + .name = "Channel 1 Quadrature A" + }, + { + .id = 1, + .name = "Channel 1 Quadrature B" + } +}; + +static struct counter_synapse stm32_count_synapses[] = { + { + .actions_list = stm32_synapse_actions, + .num_actions = ARRAY_SIZE(stm32_synapse_actions), + .signal = &stm32_signals[0] + }, + { + .actions_list = stm32_synapse_actions, + .num_actions = ARRAY_SIZE(stm32_synapse_actions), + .signal = &stm32_signals[1] + } +}; + +static struct counter_count stm32_counts = { + .id = 0, + .name = "Channel 1 Count", + .functions_list = stm32_count_functions, + .num_functions = ARRAY_SIZE(stm32_count_functions), + .synapses = stm32_count_synapses, + .num_synapses = ARRAY_SIZE(stm32_count_synapses), + .ext = stm32_count_ext, + .num_ext = ARRAY_SIZE(stm32_count_ext) +}; + +static int stm32_timer_cnt_probe(struct platform_device *pdev) +{ + struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent); + struct device *dev = &pdev->dev; + struct stm32_timer_cnt *priv; + + if (IS_ERR_OR_NULL(ddata)) + return -EINVAL; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = ddata->regmap; + priv->clk = ddata->clk; + priv->preset = ddata->max_arr; + + priv->counter.name = dev_name(dev); + priv->counter.parent = dev; + priv->counter.count_read = stm32_count_read; + priv->counter.count_write = stm32_count_write; + priv->counter.function_get = stm32_count_function_get; + priv->counter.function_set = stm32_count_function_set; + priv->counter.action_get = stm32_action_get; + priv->counter.counts = &stm32_counts; + priv->counter.num_counts = 1; + priv->counter.signals = stm32_signals; + priv->counter.num_signals = ARRAY_SIZE(stm32_signals); + priv->counter.priv = priv; + + /* Register Counter device */ + return devm_counter_register(dev, &priv->counter); +} + +static const struct of_device_id stm32_timer_cnt_of_match[] = { + { .compatible = "st,stm32-timer-counter", }, + {}, +}; +MODULE_DEVICE_TABLE(of, stm32_timer_cnt_of_match); + +static struct platform_driver stm32_timer_cnt_driver = { + .probe = stm32_timer_cnt_probe, + .driver = { + .name = "stm32-timer-counter", + .of_match_table = stm32_timer_cnt_of_match, + }, +}; +module_platform_driver(stm32_timer_cnt_driver); + +MODULE_AUTHOR("Benjamin Gaignard "); +MODULE_ALIAS("platform:stm32-timer-counter"); +MODULE_DESCRIPTION("STMicroelectronics STM32 TIMER counter driver"); +MODULE_LICENSE("GPL v2"); -- 2.16.2