| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * STM32 Timer Encoder and Counter driver |
| * |
| * Copyright (C) STMicroelectronics 2018 |
| * |
| * Author: Benjamin Gaignard <benjamin.gaignard@st.com> |
| * |
| */ |
| #include <linux/counter.h> |
| #include <linux/mfd/stm32-timers.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/module.h> |
| #include <linux/pinctrl/consumer.h> |
| #include <linux/platform_device.h> |
| #include <linux/types.h> |
| |
| #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_regs { |
| u32 cr1; |
| u32 cnt; |
| u32 smcr; |
| u32 arr; |
| }; |
| |
| struct stm32_timer_cnt { |
| struct counter_device counter; |
| struct regmap *regmap; |
| struct clk *clk; |
| u32 max_arr; |
| bool enabled; |
| struct stm32_timer_regs bak; |
| }; |
| |
| static const enum counter_function stm32_count_functions[] = { |
| COUNTER_FUNCTION_INCREASE, |
| COUNTER_FUNCTION_QUADRATURE_X2_A, |
| COUNTER_FUNCTION_QUADRATURE_X2_B, |
| COUNTER_FUNCTION_QUADRATURE_X4, |
| }; |
| |
| static int stm32_count_read(struct counter_device *counter, |
| struct counter_count *count, u64 *val) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 cnt; |
| |
| regmap_read(priv->regmap, TIM_CNT, &cnt); |
| *val = cnt; |
| |
| return 0; |
| } |
| |
| static int stm32_count_write(struct counter_device *counter, |
| struct counter_count *count, const u64 val) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 ceiling; |
| |
| regmap_read(priv->regmap, TIM_ARR, &ceiling); |
| if (val > ceiling) |
| return -EINVAL; |
| |
| return regmap_write(priv->regmap, TIM_CNT, val); |
| } |
| |
| static int stm32_count_function_read(struct counter_device *counter, |
| struct counter_count *count, |
| enum counter_function *function) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 smcr; |
| |
| regmap_read(priv->regmap, TIM_SMCR, &smcr); |
| |
| switch (smcr & TIM_SMCR_SMS) { |
| case TIM_SMCR_SMS_SLAVE_MODE_DISABLED: |
| *function = COUNTER_FUNCTION_INCREASE; |
| return 0; |
| case TIM_SMCR_SMS_ENCODER_MODE_1: |
| *function = COUNTER_FUNCTION_QUADRATURE_X2_A; |
| return 0; |
| case TIM_SMCR_SMS_ENCODER_MODE_2: |
| *function = COUNTER_FUNCTION_QUADRATURE_X2_B; |
| return 0; |
| case TIM_SMCR_SMS_ENCODER_MODE_3: |
| *function = COUNTER_FUNCTION_QUADRATURE_X4; |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static int stm32_count_function_write(struct counter_device *counter, |
| struct counter_count *count, |
| enum counter_function function) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 cr1, sms; |
| |
| switch (function) { |
| case COUNTER_FUNCTION_INCREASE: |
| sms = TIM_SMCR_SMS_SLAVE_MODE_DISABLED; |
| break; |
| case COUNTER_FUNCTION_QUADRATURE_X2_A: |
| sms = TIM_SMCR_SMS_ENCODER_MODE_1; |
| break; |
| case COUNTER_FUNCTION_QUADRATURE_X2_B: |
| sms = TIM_SMCR_SMS_ENCODER_MODE_2; |
| break; |
| case COUNTER_FUNCTION_QUADRATURE_X4: |
| sms = TIM_SMCR_SMS_ENCODER_MODE_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); |
| |
| 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 int stm32_count_direction_read(struct counter_device *counter, |
| struct counter_count *count, |
| enum counter_count_direction *direction) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 cr1; |
| |
| regmap_read(priv->regmap, TIM_CR1, &cr1); |
| *direction = (cr1 & TIM_CR1_DIR) ? COUNTER_COUNT_DIRECTION_BACKWARD : |
| COUNTER_COUNT_DIRECTION_FORWARD; |
| |
| return 0; |
| } |
| |
| static int stm32_count_ceiling_read(struct counter_device *counter, |
| struct counter_count *count, u64 *ceiling) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 arr; |
| |
| regmap_read(priv->regmap, TIM_ARR, &arr); |
| |
| *ceiling = arr; |
| |
| return 0; |
| } |
| |
| static int stm32_count_ceiling_write(struct counter_device *counter, |
| struct counter_count *count, u64 ceiling) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| |
| if (ceiling > priv->max_arr) |
| return -ERANGE; |
| |
| /* 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, ceiling); |
| |
| return 0; |
| } |
| |
| static int stm32_count_enable_read(struct counter_device *counter, |
| struct counter_count *count, u8 *enable) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 cr1; |
| |
| regmap_read(priv->regmap, TIM_CR1, &cr1); |
| |
| *enable = cr1 & TIM_CR1_CEN; |
| |
| return 0; |
| } |
| |
| static int stm32_count_enable_write(struct counter_device *counter, |
| struct counter_count *count, u8 enable) |
| { |
| struct stm32_timer_cnt *const priv = counter->priv; |
| u32 cr1; |
| |
| 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); |
| } |
| |
| /* Keep enabled state to properly handle low power states */ |
| priv->enabled = enable; |
| |
| return 0; |
| } |
| |
| static struct counter_comp stm32_count_ext[] = { |
| COUNTER_COMP_DIRECTION(stm32_count_direction_read), |
| COUNTER_COMP_ENABLE(stm32_count_enable_read, stm32_count_enable_write), |
| COUNTER_COMP_CEILING(stm32_count_ceiling_read, |
| stm32_count_ceiling_write), |
| }; |
| |
| static const enum counter_synapse_action stm32_synapse_actions[] = { |
| COUNTER_SYNAPSE_ACTION_NONE, |
| COUNTER_SYNAPSE_ACTION_BOTH_EDGES |
| }; |
| |
| static int stm32_action_read(struct counter_device *counter, |
| struct counter_count *count, |
| struct counter_synapse *synapse, |
| enum counter_synapse_action *action) |
| { |
| enum counter_function function; |
| int err; |
| |
| err = stm32_count_function_read(counter, count, &function); |
| if (err) |
| return err; |
| |
| switch (function) { |
| case COUNTER_FUNCTION_INCREASE: |
| /* counts on internal clock when CEN=1 */ |
| *action = COUNTER_SYNAPSE_ACTION_NONE; |
| return 0; |
| case COUNTER_FUNCTION_QUADRATURE_X2_A: |
| /* counts up/down on TI1FP1 edge depending on TI2FP2 level */ |
| if (synapse->signal->id == count->synapses[0].signal->id) |
| *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; |
| else |
| *action = COUNTER_SYNAPSE_ACTION_NONE; |
| return 0; |
| case COUNTER_FUNCTION_QUADRATURE_X2_B: |
| /* counts up/down on TI2FP2 edge depending on TI1FP1 level */ |
| if (synapse->signal->id == count->synapses[1].signal->id) |
| *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; |
| else |
| *action = COUNTER_SYNAPSE_ACTION_NONE; |
| return 0; |
| case COUNTER_FUNCTION_QUADRATURE_X4: |
| /* counts up/down on both TI1FP1 and TI2FP2 edges */ |
| *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; |
| return 0; |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static const struct counter_ops stm32_timer_cnt_ops = { |
| .count_read = stm32_count_read, |
| .count_write = stm32_count_write, |
| .function_read = stm32_count_function_read, |
| .function_write = stm32_count_function_write, |
| .action_read = stm32_action_read, |
| }; |
| |
| 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->max_arr = ddata->max_arr; |
| |
| priv->counter.name = dev_name(dev); |
| priv->counter.parent = dev; |
| priv->counter.ops = &stm32_timer_cnt_ops; |
| 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; |
| |
| platform_set_drvdata(pdev, priv); |
| |
| /* Register Counter device */ |
| return devm_counter_register(dev, &priv->counter); |
| } |
| |
| static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev) |
| { |
| struct stm32_timer_cnt *priv = dev_get_drvdata(dev); |
| |
| /* Only take care of enabled counter: don't disturb other MFD child */ |
| if (priv->enabled) { |
| /* Backup registers that may get lost in low power mode */ |
| regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr); |
| regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr); |
| regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt); |
| regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1); |
| |
| /* Disable the counter */ |
| regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0); |
| clk_disable(priv->clk); |
| } |
| |
| return pinctrl_pm_select_sleep_state(dev); |
| } |
| |
| static int __maybe_unused stm32_timer_cnt_resume(struct device *dev) |
| { |
| struct stm32_timer_cnt *priv = dev_get_drvdata(dev); |
| int ret; |
| |
| ret = pinctrl_pm_select_default_state(dev); |
| if (ret) |
| return ret; |
| |
| if (priv->enabled) { |
| clk_enable(priv->clk); |
| |
| /* Restore registers that may have been lost */ |
| regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr); |
| regmap_write(priv->regmap, TIM_ARR, priv->bak.arr); |
| regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt); |
| |
| /* Also re-enables the counter */ |
| regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1); |
| } |
| |
| return 0; |
| } |
| |
| static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend, |
| stm32_timer_cnt_resume); |
| |
| 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, |
| .pm = &stm32_timer_cnt_pm_ops, |
| }, |
| }; |
| module_platform_driver(stm32_timer_cnt_driver); |
| |
| MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>"); |
| MODULE_ALIAS("platform:stm32-timer-counter"); |
| MODULE_DESCRIPTION("STMicroelectronics STM32 TIMER counter driver"); |
| MODULE_LICENSE("GPL v2"); |