diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/counter/ti-ecap-capture.c | 615 |
1 files changed, 615 insertions, 0 deletions
diff --git a/drivers/counter/ti-ecap-capture.c b/drivers/counter/ti-ecap-capture.c new file mode 100644 index 000000000..fb1cb1774 --- /dev/null +++ b/drivers/counter/ti-ecap-capture.c @@ -0,0 +1,615 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ECAP Capture driver + * + * Copyright (C) 2022 Julien Panis <jpanis@baylibre.com> + */ + +#include <linux/atomic.h> +#include <linux/clk.h> +#include <linux/counter.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> + +#define ECAP_DRV_NAME "ecap" + +/* ECAP event IDs */ +#define ECAP_CEVT1 0 +#define ECAP_CEVT2 1 +#define ECAP_CEVT3 2 +#define ECAP_CEVT4 3 +#define ECAP_CNTOVF 4 + +#define ECAP_CEVT_LAST ECAP_CEVT4 +#define ECAP_NB_CEVT (ECAP_CEVT_LAST + 1) + +#define ECAP_EVT_LAST ECAP_CNTOVF +#define ECAP_NB_EVT (ECAP_EVT_LAST + 1) + +/* Registers */ +#define ECAP_TSCNT_REG 0x00 + +#define ECAP_CAP_REG(i) (((i) << 2) + 0x08) + +#define ECAP_ECCTL_REG 0x28 +#define ECAP_CAPPOL_BIT(i) BIT((i) << 1) +#define ECAP_EV_MODE_MASK GENMASK(7, 0) +#define ECAP_CAPLDEN_BIT BIT(8) +#define ECAP_CONT_ONESHT_BIT BIT(16) +#define ECAP_STOPVALUE_MASK GENMASK(18, 17) +#define ECAP_TSCNTSTP_BIT BIT(20) +#define ECAP_SYNCO_DIS_MASK GENMASK(23, 22) +#define ECAP_CAP_APWM_BIT BIT(25) +#define ECAP_ECCTL_EN_MASK (ECAP_CAPLDEN_BIT | ECAP_TSCNTSTP_BIT) +#define ECAP_ECCTL_CFG_MASK (ECAP_SYNCO_DIS_MASK | ECAP_STOPVALUE_MASK \ + | ECAP_ECCTL_EN_MASK | ECAP_CAP_APWM_BIT \ + | ECAP_CONT_ONESHT_BIT) + +#define ECAP_ECINT_EN_FLG_REG 0x2c +#define ECAP_EVT_EN_MASK GENMASK(ECAP_NB_EVT, ECAP_NB_CEVT) +#define ECAP_EVT_FLG_BIT(i) BIT((i) + 17) + +#define ECAP_ECINT_CLR_FRC_REG 0x30 +#define ECAP_INT_CLR_BIT BIT(0) +#define ECAP_EVT_CLR_BIT(i) BIT((i) + 1) +#define ECAP_EVT_CLR_MASK GENMASK(ECAP_NB_EVT, 0) + +#define ECAP_PID_REG 0x5c + +/* ECAP signals */ +#define ECAP_CLOCK_SIG 0 +#define ECAP_INPUT_SIG 1 + +static const struct regmap_config ecap_cnt_regmap_config = { + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .max_register = ECAP_PID_REG, +}; + +/** + * struct ecap_cnt_dev - device private data structure + * @enabled: device state + * @lock: synchronization lock to prevent I/O race conditions + * @clk: device clock + * @regmap: device register map + * @nb_ovf: number of overflows since capture start + * @pm_ctx: device context for PM operations + * @pm_ctx.ev_mode: event mode bits + * @pm_ctx.time_cntr: timestamp counter value + */ +struct ecap_cnt_dev { + bool enabled; + struct mutex lock; + struct clk *clk; + struct regmap *regmap; + atomic_t nb_ovf; + struct { + u8 ev_mode; + u32 time_cntr; + } pm_ctx; +}; + +static u8 ecap_cnt_capture_get_evmode(struct counter_device *counter) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + unsigned int regval; + + pm_runtime_get_sync(counter->parent); + regmap_read(ecap_dev->regmap, ECAP_ECCTL_REG, ®val); + pm_runtime_put_sync(counter->parent); + + return regval; +} + +static void ecap_cnt_capture_set_evmode(struct counter_device *counter, u8 ev_mode) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + pm_runtime_get_sync(counter->parent); + regmap_update_bits(ecap_dev->regmap, ECAP_ECCTL_REG, ECAP_EV_MODE_MASK, ev_mode); + pm_runtime_put_sync(counter->parent); +} + +static void ecap_cnt_capture_enable(struct counter_device *counter) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + pm_runtime_get_sync(counter->parent); + + /* Enable interrupts on events */ + regmap_update_bits(ecap_dev->regmap, ECAP_ECINT_EN_FLG_REG, + ECAP_EVT_EN_MASK, ECAP_EVT_EN_MASK); + + /* Run counter */ + regmap_update_bits(ecap_dev->regmap, ECAP_ECCTL_REG, ECAP_ECCTL_CFG_MASK, + ECAP_SYNCO_DIS_MASK | ECAP_STOPVALUE_MASK | ECAP_ECCTL_EN_MASK); +} + +static void ecap_cnt_capture_disable(struct counter_device *counter) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + /* Stop counter */ + regmap_update_bits(ecap_dev->regmap, ECAP_ECCTL_REG, ECAP_ECCTL_EN_MASK, 0); + + /* Disable interrupts on events */ + regmap_update_bits(ecap_dev->regmap, ECAP_ECINT_EN_FLG_REG, ECAP_EVT_EN_MASK, 0); + + pm_runtime_put_sync(counter->parent); +} + +static u32 ecap_cnt_count_get_val(struct counter_device *counter, unsigned int reg) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + unsigned int regval; + + pm_runtime_get_sync(counter->parent); + regmap_read(ecap_dev->regmap, reg, ®val); + pm_runtime_put_sync(counter->parent); + + return regval; +} + +static void ecap_cnt_count_set_val(struct counter_device *counter, unsigned int reg, u32 val) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + pm_runtime_get_sync(counter->parent); + regmap_write(ecap_dev->regmap, reg, val); + pm_runtime_put_sync(counter->parent); +} + +static int ecap_cnt_count_read(struct counter_device *counter, + struct counter_count *count, u64 *val) +{ + *val = ecap_cnt_count_get_val(counter, ECAP_TSCNT_REG); + + return 0; +} + +static int ecap_cnt_count_write(struct counter_device *counter, + struct counter_count *count, u64 val) +{ + if (val > U32_MAX) + return -ERANGE; + + ecap_cnt_count_set_val(counter, ECAP_TSCNT_REG, val); + + return 0; +} + +static int ecap_cnt_function_read(struct counter_device *counter, + struct counter_count *count, + enum counter_function *function) +{ + *function = COUNTER_FUNCTION_INCREASE; + + return 0; +} + +static int ecap_cnt_action_read(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + enum counter_synapse_action *action) +{ + *action = (synapse->signal->id == ECAP_CLOCK_SIG) ? + COUNTER_SYNAPSE_ACTION_RISING_EDGE : + COUNTER_SYNAPSE_ACTION_NONE; + + return 0; +} + +static int ecap_cnt_watch_validate(struct counter_device *counter, + const struct counter_watch *watch) +{ + if (watch->channel > ECAP_CEVT_LAST) + return -EINVAL; + + switch (watch->event) { + case COUNTER_EVENT_CAPTURE: + case COUNTER_EVENT_OVERFLOW: + return 0; + default: + return -EINVAL; + } +} + +static int ecap_cnt_clk_get_freq(struct counter_device *counter, + struct counter_signal *signal, u64 *freq) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + *freq = clk_get_rate(ecap_dev->clk); + + return 0; +} + +static int ecap_cnt_pol_read(struct counter_device *counter, + struct counter_signal *signal, + size_t idx, enum counter_signal_polarity *pol) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + int bitval; + + pm_runtime_get_sync(counter->parent); + bitval = regmap_test_bits(ecap_dev->regmap, ECAP_ECCTL_REG, ECAP_CAPPOL_BIT(idx)); + pm_runtime_put_sync(counter->parent); + + *pol = bitval ? COUNTER_SIGNAL_POLARITY_NEGATIVE : COUNTER_SIGNAL_POLARITY_POSITIVE; + + return 0; +} + +static int ecap_cnt_pol_write(struct counter_device *counter, + struct counter_signal *signal, + size_t idx, enum counter_signal_polarity pol) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + pm_runtime_get_sync(counter->parent); + if (pol == COUNTER_SIGNAL_POLARITY_NEGATIVE) + regmap_set_bits(ecap_dev->regmap, ECAP_ECCTL_REG, ECAP_CAPPOL_BIT(idx)); + else + regmap_clear_bits(ecap_dev->regmap, ECAP_ECCTL_REG, ECAP_CAPPOL_BIT(idx)); + pm_runtime_put_sync(counter->parent); + + return 0; +} + +static int ecap_cnt_cap_read(struct counter_device *counter, + struct counter_count *count, + size_t idx, u64 *cap) +{ + *cap = ecap_cnt_count_get_val(counter, ECAP_CAP_REG(idx)); + + return 0; +} + +static int ecap_cnt_cap_write(struct counter_device *counter, + struct counter_count *count, + size_t idx, u64 cap) +{ + if (cap > U32_MAX) + return -ERANGE; + + ecap_cnt_count_set_val(counter, ECAP_CAP_REG(idx), cap); + + return 0; +} + +static int ecap_cnt_nb_ovf_read(struct counter_device *counter, + struct counter_count *count, u64 *val) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + *val = atomic_read(&ecap_dev->nb_ovf); + + return 0; +} + +static int ecap_cnt_nb_ovf_write(struct counter_device *counter, + struct counter_count *count, u64 val) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + if (val > U32_MAX) + return -ERANGE; + + atomic_set(&ecap_dev->nb_ovf, val); + + return 0; +} + +static int ecap_cnt_ceiling_read(struct counter_device *counter, + struct counter_count *count, u64 *val) +{ + *val = U32_MAX; + + return 0; +} + +static int ecap_cnt_enable_read(struct counter_device *counter, + struct counter_count *count, u8 *enable) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + *enable = ecap_dev->enabled; + + return 0; +} + +static int ecap_cnt_enable_write(struct counter_device *counter, + struct counter_count *count, u8 enable) +{ + struct ecap_cnt_dev *ecap_dev = counter_priv(counter); + + mutex_lock(&ecap_dev->lock); + + if (enable == ecap_dev->enabled) + goto out; + + if (enable) + ecap_cnt_capture_enable(counter); + else + ecap_cnt_capture_disable(counter); + ecap_dev->enabled = enable; + +out: + mutex_unlock(&ecap_dev->lock); + + return 0; +} + +static const struct counter_ops ecap_cnt_ops = { + .count_read = ecap_cnt_count_read, + .count_write = ecap_cnt_count_write, + .function_read = ecap_cnt_function_read, + .action_read = ecap_cnt_action_read, + .watch_validate = ecap_cnt_watch_validate, +}; + +static const enum counter_function ecap_cnt_functions[] = { + COUNTER_FUNCTION_INCREASE, +}; + +static const enum counter_synapse_action ecap_cnt_clock_actions[] = { + COUNTER_SYNAPSE_ACTION_RISING_EDGE, +}; + +static const enum counter_synapse_action ecap_cnt_input_actions[] = { + COUNTER_SYNAPSE_ACTION_NONE, +}; + +static struct counter_comp ecap_cnt_clock_ext[] = { + COUNTER_COMP_SIGNAL_U64("frequency", ecap_cnt_clk_get_freq, NULL), +}; + +static const enum counter_signal_polarity ecap_cnt_pol_avail[] = { + COUNTER_SIGNAL_POLARITY_POSITIVE, + COUNTER_SIGNAL_POLARITY_NEGATIVE, +}; + +static DEFINE_COUNTER_AVAILABLE(ecap_cnt_pol_available, ecap_cnt_pol_avail); +static DEFINE_COUNTER_ARRAY_POLARITY(ecap_cnt_pol_array, ecap_cnt_pol_available, ECAP_NB_CEVT); + +static struct counter_comp ecap_cnt_signal_ext[] = { + COUNTER_COMP_ARRAY_POLARITY(ecap_cnt_pol_read, ecap_cnt_pol_write, ecap_cnt_pol_array), +}; + +static struct counter_signal ecap_cnt_signals[] = { + { + .id = ECAP_CLOCK_SIG, + .name = "Clock Signal", + .ext = ecap_cnt_clock_ext, + .num_ext = ARRAY_SIZE(ecap_cnt_clock_ext), + }, + { + .id = ECAP_INPUT_SIG, + .name = "Input Signal", + .ext = ecap_cnt_signal_ext, + .num_ext = ARRAY_SIZE(ecap_cnt_signal_ext), + }, +}; + +static struct counter_synapse ecap_cnt_synapses[] = { + { + .actions_list = ecap_cnt_clock_actions, + .num_actions = ARRAY_SIZE(ecap_cnt_clock_actions), + .signal = &ecap_cnt_signals[ECAP_CLOCK_SIG], + }, + { + .actions_list = ecap_cnt_input_actions, + .num_actions = ARRAY_SIZE(ecap_cnt_input_actions), + .signal = &ecap_cnt_signals[ECAP_INPUT_SIG], + }, +}; + +static DEFINE_COUNTER_ARRAY_CAPTURE(ecap_cnt_cap_array, ECAP_NB_CEVT); + +static struct counter_comp ecap_cnt_count_ext[] = { + COUNTER_COMP_ARRAY_CAPTURE(ecap_cnt_cap_read, ecap_cnt_cap_write, ecap_cnt_cap_array), + COUNTER_COMP_COUNT_U64("num_overflows", ecap_cnt_nb_ovf_read, ecap_cnt_nb_ovf_write), + COUNTER_COMP_CEILING(ecap_cnt_ceiling_read, NULL), + COUNTER_COMP_ENABLE(ecap_cnt_enable_read, ecap_cnt_enable_write), +}; + +static struct counter_count ecap_cnt_counts[] = { + { + .name = "Timestamp Counter", + .functions_list = ecap_cnt_functions, + .num_functions = ARRAY_SIZE(ecap_cnt_functions), + .synapses = ecap_cnt_synapses, + .num_synapses = ARRAY_SIZE(ecap_cnt_synapses), + .ext = ecap_cnt_count_ext, + .num_ext = ARRAY_SIZE(ecap_cnt_count_ext), + }, +}; + +static irqreturn_t ecap_cnt_isr(int irq, void *dev_id) +{ + struct counter_device *counter_dev = dev_id; + struct ecap_cnt_dev *ecap_dev = counter_priv(counter_dev); + unsigned int clr = 0; + unsigned int flg; + int i; + + regmap_read(ecap_dev->regmap, ECAP_ECINT_EN_FLG_REG, &flg); + + /* Check capture events */ + for (i = 0 ; i < ECAP_NB_CEVT ; i++) { + if (flg & ECAP_EVT_FLG_BIT(i)) { + counter_push_event(counter_dev, COUNTER_EVENT_CAPTURE, i); + clr |= ECAP_EVT_CLR_BIT(i); + } + } + + /* Check counter overflow */ + if (flg & ECAP_EVT_FLG_BIT(ECAP_CNTOVF)) { + atomic_inc(&ecap_dev->nb_ovf); + for (i = 0 ; i < ECAP_NB_CEVT ; i++) + counter_push_event(counter_dev, COUNTER_EVENT_OVERFLOW, i); + clr |= ECAP_EVT_CLR_BIT(ECAP_CNTOVF); + } + + clr |= ECAP_INT_CLR_BIT; + regmap_update_bits(ecap_dev->regmap, ECAP_ECINT_CLR_FRC_REG, ECAP_EVT_CLR_MASK, clr); + + return IRQ_HANDLED; +} + +static void ecap_cnt_pm_disable(void *dev) +{ + pm_runtime_disable(dev); +} + +static int ecap_cnt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct ecap_cnt_dev *ecap_dev; + struct counter_device *counter_dev; + void __iomem *mmio_base; + unsigned long clk_rate; + int ret; + + counter_dev = devm_counter_alloc(dev, sizeof(*ecap_dev)); + if (!counter_dev) + return -ENOMEM; + + counter_dev->name = ECAP_DRV_NAME; + counter_dev->parent = dev; + counter_dev->ops = &ecap_cnt_ops; + counter_dev->signals = ecap_cnt_signals; + counter_dev->num_signals = ARRAY_SIZE(ecap_cnt_signals); + counter_dev->counts = ecap_cnt_counts; + counter_dev->num_counts = ARRAY_SIZE(ecap_cnt_counts); + + ecap_dev = counter_priv(counter_dev); + + mutex_init(&ecap_dev->lock); + + ecap_dev->clk = devm_clk_get_enabled(dev, "fck"); + if (IS_ERR(ecap_dev->clk)) + return dev_err_probe(dev, PTR_ERR(ecap_dev->clk), "failed to get clock\n"); + + clk_rate = clk_get_rate(ecap_dev->clk); + if (!clk_rate) { + dev_err(dev, "failed to get clock rate\n"); + return -EINVAL; + } + + mmio_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(mmio_base)) + return PTR_ERR(mmio_base); + + ecap_dev->regmap = devm_regmap_init_mmio(dev, mmio_base, &ecap_cnt_regmap_config); + if (IS_ERR(ecap_dev->regmap)) + return dev_err_probe(dev, PTR_ERR(ecap_dev->regmap), "failed to init regmap\n"); + + ret = platform_get_irq(pdev, 0); + if (ret < 0) + return dev_err_probe(dev, ret, "failed to get irq\n"); + + ret = devm_request_irq(dev, ret, ecap_cnt_isr, 0, pdev->name, counter_dev); + if (ret) + return dev_err_probe(dev, ret, "failed to request irq\n"); + + platform_set_drvdata(pdev, counter_dev); + + pm_runtime_enable(dev); + + /* Register a cleanup callback to care for disabling PM */ + ret = devm_add_action_or_reset(dev, ecap_cnt_pm_disable, dev); + if (ret) + return dev_err_probe(dev, ret, "failed to add pm disable action\n"); + + ret = devm_counter_add(dev, counter_dev); + if (ret) + return dev_err_probe(dev, ret, "failed to add counter\n"); + + return 0; +} + +static int ecap_cnt_remove(struct platform_device *pdev) +{ + struct counter_device *counter_dev = platform_get_drvdata(pdev); + struct ecap_cnt_dev *ecap_dev = counter_priv(counter_dev); + + if (ecap_dev->enabled) + ecap_cnt_capture_disable(counter_dev); + + return 0; +} + +static int ecap_cnt_suspend(struct device *dev) +{ + struct counter_device *counter_dev = dev_get_drvdata(dev); + struct ecap_cnt_dev *ecap_dev = counter_priv(counter_dev); + + /* If eCAP is running, stop capture then save timestamp counter */ + if (ecap_dev->enabled) { + /* + * Disabling capture has the following effects: + * - interrupts are disabled + * - loading of capture registers is disabled + * - timebase counter is stopped + */ + ecap_cnt_capture_disable(counter_dev); + ecap_dev->pm_ctx.time_cntr = ecap_cnt_count_get_val(counter_dev, ECAP_TSCNT_REG); + } + + ecap_dev->pm_ctx.ev_mode = ecap_cnt_capture_get_evmode(counter_dev); + + clk_disable(ecap_dev->clk); + + return 0; +} + +static int ecap_cnt_resume(struct device *dev) +{ + struct counter_device *counter_dev = dev_get_drvdata(dev); + struct ecap_cnt_dev *ecap_dev = counter_priv(counter_dev); + + clk_enable(ecap_dev->clk); + + ecap_cnt_capture_set_evmode(counter_dev, ecap_dev->pm_ctx.ev_mode); + + /* If eCAP was running, restore timestamp counter then run capture */ + if (ecap_dev->enabled) { + ecap_cnt_count_set_val(counter_dev, ECAP_TSCNT_REG, ecap_dev->pm_ctx.time_cntr); + ecap_cnt_capture_enable(counter_dev); + } + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(ecap_cnt_pm_ops, ecap_cnt_suspend, ecap_cnt_resume); + +static const struct of_device_id ecap_cnt_of_match[] = { + { .compatible = "ti,am62-ecap-capture" }, + {}, +}; +MODULE_DEVICE_TABLE(of, ecap_cnt_of_match); + +static struct platform_driver ecap_cnt_driver = { + .probe = ecap_cnt_probe, + .remove = ecap_cnt_remove, + .driver = { + .name = "ecap-capture", + .of_match_table = ecap_cnt_of_match, + .pm = pm_sleep_ptr(&ecap_cnt_pm_ops), + }, +}; +module_platform_driver(ecap_cnt_driver); + +MODULE_DESCRIPTION("ECAP Capture driver"); +MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(COUNTER); |