| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2020 Microchip |
| * |
| * Author: Kamel Bouhara <kamel.bouhara@bootlin.com> |
| */ |
| #include <linux/clk.h> |
| #include <linux/counter.h> |
| #include <linux/mfd/syscon.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| #include <linux/platform_device.h> |
| #include <linux/regmap.h> |
| #include <soc/at91/atmel_tcb.h> |
| |
| #define ATMEL_TC_CMR_MASK (ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \ |
| ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \ |
| ATMEL_TC_LDBSTOP) |
| |
| #define ATMEL_TC_QDEN BIT(8) |
| #define ATMEL_TC_POSEN BIT(9) |
| |
| struct mchp_tc_data { |
| const struct atmel_tcb_config *tc_cfg; |
| struct regmap *regmap; |
| int qdec_mode; |
| int num_channels; |
| int channel[2]; |
| }; |
| |
| static const enum counter_function mchp_tc_count_functions[] = { |
| COUNTER_FUNCTION_INCREASE, |
| COUNTER_FUNCTION_QUADRATURE_X4, |
| }; |
| |
| static const enum counter_synapse_action mchp_tc_synapse_actions[] = { |
| COUNTER_SYNAPSE_ACTION_NONE, |
| COUNTER_SYNAPSE_ACTION_RISING_EDGE, |
| COUNTER_SYNAPSE_ACTION_FALLING_EDGE, |
| COUNTER_SYNAPSE_ACTION_BOTH_EDGES, |
| }; |
| |
| static struct counter_signal mchp_tc_count_signals[] = { |
| { |
| .id = 0, |
| .name = "Channel A", |
| }, |
| { |
| .id = 1, |
| .name = "Channel B", |
| } |
| }; |
| |
| static struct counter_synapse mchp_tc_count_synapses[] = { |
| { |
| .actions_list = mchp_tc_synapse_actions, |
| .num_actions = ARRAY_SIZE(mchp_tc_synapse_actions), |
| .signal = &mchp_tc_count_signals[0] |
| }, |
| { |
| .actions_list = mchp_tc_synapse_actions, |
| .num_actions = ARRAY_SIZE(mchp_tc_synapse_actions), |
| .signal = &mchp_tc_count_signals[1] |
| } |
| }; |
| |
| static int mchp_tc_count_function_read(struct counter_device *counter, |
| struct counter_count *count, |
| enum counter_function *function) |
| { |
| struct mchp_tc_data *const priv = counter_priv(counter); |
| |
| if (priv->qdec_mode) |
| *function = COUNTER_FUNCTION_QUADRATURE_X4; |
| else |
| *function = COUNTER_FUNCTION_INCREASE; |
| |
| return 0; |
| } |
| |
| static int mchp_tc_count_function_write(struct counter_device *counter, |
| struct counter_count *count, |
| enum counter_function function) |
| { |
| struct mchp_tc_data *const priv = counter_priv(counter); |
| u32 bmr, cmr; |
| |
| regmap_read(priv->regmap, ATMEL_TC_BMR, &bmr); |
| regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); |
| |
| /* Set capture mode */ |
| cmr &= ~ATMEL_TC_WAVE; |
| |
| switch (function) { |
| case COUNTER_FUNCTION_INCREASE: |
| priv->qdec_mode = 0; |
| /* Set highest rate based on whether soc has gclk or not */ |
| bmr &= ~(ATMEL_TC_QDEN | ATMEL_TC_POSEN); |
| if (priv->tc_cfg->has_gclk) |
| cmr |= ATMEL_TC_TIMER_CLOCK2; |
| else |
| cmr |= ATMEL_TC_TIMER_CLOCK1; |
| /* Setup the period capture mode */ |
| cmr |= ATMEL_TC_CMR_MASK; |
| cmr &= ~(ATMEL_TC_ABETRG | ATMEL_TC_XC0); |
| break; |
| case COUNTER_FUNCTION_QUADRATURE_X4: |
| if (!priv->tc_cfg->has_qdec) |
| return -EINVAL; |
| /* In QDEC mode settings both channels 0 and 1 are required */ |
| if (priv->num_channels < 2 || priv->channel[0] != 0 || |
| priv->channel[1] != 1) { |
| pr_err("Invalid channels number or id for quadrature mode\n"); |
| return -EINVAL; |
| } |
| priv->qdec_mode = 1; |
| bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN; |
| cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0; |
| break; |
| default: |
| /* should never reach this path */ |
| return -EINVAL; |
| } |
| |
| regmap_write(priv->regmap, ATMEL_TC_BMR, bmr); |
| regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), cmr); |
| |
| /* Enable clock and trigger counter */ |
| regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CCR), |
| ATMEL_TC_CLKEN | ATMEL_TC_SWTRG); |
| |
| if (priv->qdec_mode) { |
| regmap_write(priv->regmap, |
| ATMEL_TC_REG(priv->channel[1], CMR), cmr); |
| regmap_write(priv->regmap, |
| ATMEL_TC_REG(priv->channel[1], CCR), |
| ATMEL_TC_CLKEN | ATMEL_TC_SWTRG); |
| } |
| |
| return 0; |
| } |
| |
| static int mchp_tc_count_signal_read(struct counter_device *counter, |
| struct counter_signal *signal, |
| enum counter_signal_level *lvl) |
| { |
| struct mchp_tc_data *const priv = counter_priv(counter); |
| bool sigstatus; |
| u32 sr; |
| |
| regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr); |
| |
| if (signal->id == 1) |
| sigstatus = (sr & ATMEL_TC_MTIOB); |
| else |
| sigstatus = (sr & ATMEL_TC_MTIOA); |
| |
| *lvl = sigstatus ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW; |
| |
| return 0; |
| } |
| |
| static int mchp_tc_count_action_read(struct counter_device *counter, |
| struct counter_count *count, |
| struct counter_synapse *synapse, |
| enum counter_synapse_action *action) |
| { |
| struct mchp_tc_data *const priv = counter_priv(counter); |
| u32 cmr; |
| |
| if (priv->qdec_mode) { |
| *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; |
| return 0; |
| } |
| |
| /* Only TIOA signal is evaluated in non-QDEC mode */ |
| if (synapse->signal->id != 0) { |
| *action = COUNTER_SYNAPSE_ACTION_NONE; |
| return 0; |
| } |
| |
| regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); |
| |
| switch (cmr & ATMEL_TC_ETRGEDG) { |
| default: |
| *action = COUNTER_SYNAPSE_ACTION_NONE; |
| break; |
| case ATMEL_TC_ETRGEDG_RISING: |
| *action = COUNTER_SYNAPSE_ACTION_RISING_EDGE; |
| break; |
| case ATMEL_TC_ETRGEDG_FALLING: |
| *action = COUNTER_SYNAPSE_ACTION_FALLING_EDGE; |
| break; |
| case ATMEL_TC_ETRGEDG_BOTH: |
| *action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES; |
| break; |
| } |
| |
| return 0; |
| } |
| |
| static int mchp_tc_count_action_write(struct counter_device *counter, |
| struct counter_count *count, |
| struct counter_synapse *synapse, |
| enum counter_synapse_action action) |
| { |
| struct mchp_tc_data *const priv = counter_priv(counter); |
| u32 edge = ATMEL_TC_ETRGEDG_NONE; |
| |
| /* QDEC mode is rising edge only; only TIOA handled in non-QDEC mode */ |
| if (priv->qdec_mode || synapse->signal->id != 0) |
| return -EINVAL; |
| |
| switch (action) { |
| case COUNTER_SYNAPSE_ACTION_NONE: |
| edge = ATMEL_TC_ETRGEDG_NONE; |
| break; |
| case COUNTER_SYNAPSE_ACTION_RISING_EDGE: |
| edge = ATMEL_TC_ETRGEDG_RISING; |
| break; |
| case COUNTER_SYNAPSE_ACTION_FALLING_EDGE: |
| edge = ATMEL_TC_ETRGEDG_FALLING; |
| break; |
| case COUNTER_SYNAPSE_ACTION_BOTH_EDGES: |
| edge = ATMEL_TC_ETRGEDG_BOTH; |
| break; |
| default: |
| /* should never reach this path */ |
| return -EINVAL; |
| } |
| |
| return regmap_write_bits(priv->regmap, |
| ATMEL_TC_REG(priv->channel[0], CMR), |
| ATMEL_TC_ETRGEDG, edge); |
| } |
| |
| static int mchp_tc_count_read(struct counter_device *counter, |
| struct counter_count *count, u64 *val) |
| { |
| struct mchp_tc_data *const priv = counter_priv(counter); |
| u32 cnt; |
| |
| regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt); |
| *val = cnt; |
| |
| return 0; |
| } |
| |
| static struct counter_count mchp_tc_counts[] = { |
| { |
| .id = 0, |
| .name = "Timer Counter", |
| .functions_list = mchp_tc_count_functions, |
| .num_functions = ARRAY_SIZE(mchp_tc_count_functions), |
| .synapses = mchp_tc_count_synapses, |
| .num_synapses = ARRAY_SIZE(mchp_tc_count_synapses), |
| }, |
| }; |
| |
| static const struct counter_ops mchp_tc_ops = { |
| .signal_read = mchp_tc_count_signal_read, |
| .count_read = mchp_tc_count_read, |
| .function_read = mchp_tc_count_function_read, |
| .function_write = mchp_tc_count_function_write, |
| .action_read = mchp_tc_count_action_read, |
| .action_write = mchp_tc_count_action_write |
| }; |
| |
| static const struct atmel_tcb_config tcb_rm9200_config = { |
| .counter_width = 16, |
| }; |
| |
| static const struct atmel_tcb_config tcb_sam9x5_config = { |
| .counter_width = 32, |
| }; |
| |
| static const struct atmel_tcb_config tcb_sama5d2_config = { |
| .counter_width = 32, |
| .has_gclk = true, |
| .has_qdec = true, |
| }; |
| |
| static const struct atmel_tcb_config tcb_sama5d3_config = { |
| .counter_width = 32, |
| .has_qdec = true, |
| }; |
| |
| static const struct of_device_id atmel_tc_of_match[] = { |
| { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, }, |
| { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, }, |
| { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, }, |
| { .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, }, |
| { /* sentinel */ } |
| }; |
| |
| static void mchp_tc_clk_remove(void *ptr) |
| { |
| clk_disable_unprepare((struct clk *)ptr); |
| } |
| |
| static int mchp_tc_probe(struct platform_device *pdev) |
| { |
| struct device_node *np = pdev->dev.of_node; |
| const struct atmel_tcb_config *tcb_config; |
| const struct of_device_id *match; |
| struct counter_device *counter; |
| struct mchp_tc_data *priv; |
| char clk_name[7]; |
| struct regmap *regmap; |
| struct clk *clk[3]; |
| int channel; |
| int ret, i; |
| |
| counter = devm_counter_alloc(&pdev->dev, sizeof(*priv)); |
| if (!counter) |
| return -ENOMEM; |
| priv = counter_priv(counter); |
| |
| match = of_match_node(atmel_tc_of_match, np->parent); |
| tcb_config = match->data; |
| if (!tcb_config) { |
| dev_err(&pdev->dev, "No matching parent node found\n"); |
| return -ENODEV; |
| } |
| |
| regmap = syscon_node_to_regmap(np->parent); |
| if (IS_ERR(regmap)) |
| return PTR_ERR(regmap); |
| |
| /* max. channels number is 2 when in QDEC mode */ |
| priv->num_channels = of_property_count_u32_elems(np, "reg"); |
| if (priv->num_channels < 0) { |
| dev_err(&pdev->dev, "Invalid or missing channel\n"); |
| return -EINVAL; |
| } |
| |
| /* Register channels and initialize clocks */ |
| for (i = 0; i < priv->num_channels; i++) { |
| ret = of_property_read_u32_index(np, "reg", i, &channel); |
| if (ret < 0 || channel > 2) |
| return -ENODEV; |
| |
| priv->channel[i] = channel; |
| |
| snprintf(clk_name, sizeof(clk_name), "t%d_clk", channel); |
| |
| clk[i] = of_clk_get_by_name(np->parent, clk_name); |
| if (IS_ERR(clk[i])) { |
| /* Fallback to t0_clk */ |
| clk[i] = of_clk_get_by_name(np->parent, "t0_clk"); |
| if (IS_ERR(clk[i])) |
| return PTR_ERR(clk[i]); |
| } |
| |
| ret = clk_prepare_enable(clk[i]); |
| if (ret) |
| return ret; |
| |
| ret = devm_add_action_or_reset(&pdev->dev, |
| mchp_tc_clk_remove, |
| clk[i]); |
| if (ret) |
| return ret; |
| |
| dev_dbg(&pdev->dev, |
| "Initialized capture mode on channel %d\n", |
| channel); |
| } |
| |
| priv->tc_cfg = tcb_config; |
| priv->regmap = regmap; |
| counter->name = dev_name(&pdev->dev); |
| counter->parent = &pdev->dev; |
| counter->ops = &mchp_tc_ops; |
| counter->num_counts = ARRAY_SIZE(mchp_tc_counts); |
| counter->counts = mchp_tc_counts; |
| counter->num_signals = ARRAY_SIZE(mchp_tc_count_signals); |
| counter->signals = mchp_tc_count_signals; |
| |
| ret = devm_counter_add(&pdev->dev, counter); |
| if (ret < 0) |
| return dev_err_probe(&pdev->dev, ret, "Failed to add counter\n"); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id mchp_tc_dt_ids[] = { |
| { .compatible = "microchip,tcb-capture", }, |
| { /* sentinel */ }, |
| }; |
| MODULE_DEVICE_TABLE(of, mchp_tc_dt_ids); |
| |
| static struct platform_driver mchp_tc_driver = { |
| .probe = mchp_tc_probe, |
| .driver = { |
| .name = "microchip-tcb-capture", |
| .of_match_table = mchp_tc_dt_ids, |
| }, |
| }; |
| module_platform_driver(mchp_tc_driver); |
| |
| MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); |
| MODULE_DESCRIPTION("Microchip TCB Capture driver"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_IMPORT_NS(COUNTER); |