From patchwork Mon Apr 6 15:53:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamel BOUHARA X-Patchwork-Id: 11475729 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2B9E8174A for ; Mon, 6 Apr 2020 15:54:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14EE321D94 for ; Mon, 6 Apr 2020 15:54:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729210AbgDFPyS (ORCPT ); Mon, 6 Apr 2020 11:54:18 -0400 Received: from relay9-d.mail.gandi.net ([217.70.183.199]:39607 "EHLO relay9-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729195AbgDFPyR (ORCPT ); Mon, 6 Apr 2020 11:54:17 -0400 X-Originating-IP: 78.193.40.249 Received: from localhost (unknown [78.193.40.249]) (Authenticated sender: kamel.bouhara@bootlin.com) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id A6C5DFF809; Mon, 6 Apr 2020 15:54:14 +0000 (UTC) From: Kamel Bouhara To: William Breathitt Gray , Rob Herring , Mark Rutland , Nicolas Ferre , Alexandre Belloni , Ludovic Desroches , linux-arm-kernel@lists.infradead.org Cc: Thomas Petazzoni , linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, Kamel Bouhara Subject: [PATCH 3/3] counter: Add atmel TCB capture counter Date: Mon, 6 Apr 2020 17:53:20 +0200 Message-Id: <20200406155320.1291701-4-kamel.bouhara@bootlin.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200406155320.1291701-1-kamel.bouhara@bootlin.com> References: <20200406155320.1291701-1-kamel.bouhara@bootlin.com> MIME-Version: 1.0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org This drivers allows to use the capture mode of the Timer Counter Block hardware block available in Atmel SoCs through the counter subsystem. Two functions of the counter are supported for the moment: period capture and quadrature decoder. The latter is only supported by the SAMA5 series of SoCs. For the period capture mode a basic setup has been chosen that will reset the counter each time the period is actually reached. Of course the device offers much more possibilities. For quadrature mode, both channel 0 and 1 must be configured even if we only capture the position (no revolution/rotation). Signed-off-by: Kamel Bouhara --- drivers/counter/Kconfig | 11 + drivers/counter/Makefile | 1 + drivers/counter/atmel-tcb-capture.c | 388 ++++++++++++++++++++++++++++ 3 files changed, 400 insertions(+) create mode 100644 drivers/counter/atmel-tcb-capture.c diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig index c80fa76bb531..c50d7453ec33 100644 --- a/drivers/counter/Kconfig +++ b/drivers/counter/Kconfig @@ -70,4 +70,15 @@ config FTM_QUADDEC To compile this driver as a module, choose M here: the module will be called ftm-quaddec. +config ATMEL_TCB_CAPTURE + tristate "Atmel Timer Counter Capture driver" + depends on HAS_IOMEM && OF + select REGMAP_MMIO + help + Select this option to enable the Atmel Timer Counter Block + capture driver. + + To compile this driver as a module, choose M here: the + module will be called atmel-tcb-capture. + endif # COUNTER diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile index 55142d1f4c43..70c5b8924588 100644 --- a/drivers/counter/Makefile +++ b/drivers/counter/Makefile @@ -10,3 +10,4 @@ obj-$(CONFIG_STM32_TIMER_CNT) += stm32-timer-cnt.o obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o obj-$(CONFIG_TI_EQEP) += ti-eqep.o obj-$(CONFIG_FTM_QUADDEC) += ftm-quaddec.o +obj-$(CONFIG_ATMEL_TCB_CAPTURE) += atmel-tcb-capture.o diff --git a/drivers/counter/atmel-tcb-capture.c b/drivers/counter/atmel-tcb-capture.c new file mode 100644 index 000000000000..6ac809503f90 --- /dev/null +++ b/drivers/counter/atmel-tcb-capture.c @@ -0,0 +1,388 @@ +// SPDX-License-Identifier: GPL-2.0-only +/** + * Copyright (C) 2020 Atmel + * + * Author: Kamel Bouhara + * + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 atmel_tc_data { + const struct atmel_tcb_config *tc_cfg; + struct counter_device counter; + struct regmap *regmap; + int qdec_mode; + int num_channels; + int channel[2]; + bool trig_inverted; +}; + +enum atmel_tc_count_function { + ATMEL_TC_FUNCTION_INCREASE, + ATMEL_TC_FUNCTION_QUADRATURE, +}; + +static enum counter_count_function atmel_tc_count_functions[] = { + [ATMEL_TC_FUNCTION_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE, + [ATMEL_TC_FUNCTION_QUADRATURE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4, +}; + +enum atmel_tc_synapse_action { + ATMEL_TC_SYNAPSE_ACTION_NONE = 0, + ATMEL_TC_SYNAPSE_ACTION_RISING_EDGE, + ATMEL_TC_SYNAPSE_ACTION_FALLING_EDGE, + ATMEL_TC_SYNAPSE_ACTION_BOTH_EDGE +}; + +static enum counter_synapse_action atmel_tc_synapse_actions[] = { + [ATMEL_TC_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE, + [ATMEL_TC_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE, + [ATMEL_TC_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE, + [ATMEL_TC_SYNAPSE_ACTION_BOTH_EDGE] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES, +}; + +static struct counter_signal atmel_tc_count_signals[] = { + { + .id = 0, + .name = "Channel A", + }, + { + .id = 1, + .name = "Channel B", + } +}; + +static struct counter_synapse atmel_tc_count_synapses[] = { + { + .actions_list = atmel_tc_synapse_actions, + .num_actions = ARRAY_SIZE(atmel_tc_synapse_actions), + .signal = &atmel_tc_count_signals[0] + }, + { + .actions_list = atmel_tc_synapse_actions, + .num_actions = ARRAY_SIZE(atmel_tc_synapse_actions), + .signal = &atmel_tc_count_signals[1] + } +}; + +static int atmel_tc_count_function_get(struct counter_device *counter, + struct counter_count *count, + size_t *function) +{ + struct atmel_tc_data *const priv = counter->priv; + + if (priv->qdec_mode) + *function = ATMEL_TC_FUNCTION_QUADRATURE; + else + *function = ATMEL_TC_FUNCTION_INCREASE; + + return 0; +} + +static int atmel_tc_count_function_set(struct counter_device *counter, + struct counter_count *count, + size_t function) +{ + struct atmel_tc_data *const priv = counter->priv; + 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 ATMEL_TC_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 ATMEL_TC_FUNCTION_QUADRATURE: + if (!priv->tc_cfg->has_qdec) + return -ENODEV; + /* 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; + } + + 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 atmel_tc_count_signal_read(struct counter_device *counter, + struct counter_signal *signal, + enum counter_signal_value *val) +{ + struct atmel_tc_data *const priv = counter->priv; + bool sigstatus; + u32 sr; + + regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr); + + if (priv->trig_inverted) + sigstatus = (sr & ATMEL_TC_MTIOB); + else + sigstatus = (sr & ATMEL_TC_MTIOA); + + *val = sigstatus ? COUNTER_SIGNAL_HIGH : COUNTER_SIGNAL_LOW; + + return 0; +} + +static int atmel_tc_count_action_get(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + size_t *action) +{ + struct atmel_tc_data *const priv = counter->priv; + u32 cmr; + + regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); + + *action = ATMEL_TC_SYNAPSE_ACTION_NONE; + + if (cmr & ATMEL_TC_ETRGEDG_NONE) + *action = ATMEL_TC_SYNAPSE_ACTION_NONE; + else if (cmr & ATMEL_TC_ETRGEDG_RISING) + *action = ATMEL_TC_SYNAPSE_ACTION_RISING_EDGE; + else if (cmr & ATMEL_TC_ETRGEDG_FALLING) + *action = ATMEL_TC_SYNAPSE_ACTION_FALLING_EDGE; + else if (cmr & ATMEL_TC_ETRGEDG_BOTH) + *action = ATMEL_TC_SYNAPSE_ACTION_BOTH_EDGE; + + return 0; +} + +static int atmel_tc_count_action_set(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + size_t action) +{ + struct atmel_tc_data *const priv = counter->priv; + u32 edge = ATMEL_TC_ETRGEDG_NONE; + + switch (action) { + case ATMEL_TC_SYNAPSE_ACTION_NONE: + edge = ATMEL_TC_ETRGEDG_NONE; + break; + case ATMEL_TC_SYNAPSE_ACTION_RISING_EDGE: + edge = ATMEL_TC_ETRGEDG_RISING; + break; + case ATMEL_TC_SYNAPSE_ACTION_FALLING_EDGE: + edge = ATMEL_TC_ETRGEDG_FALLING; + break; + case ATMEL_TC_SYNAPSE_ACTION_BOTH_EDGE: + edge = ATMEL_TC_ETRGEDG_BOTH; + break; + } + + return regmap_write_bits(priv->regmap, + ATMEL_TC_REG(priv->channel[0], CMR), + ATMEL_TC_ETRGEDG, edge); +} + +static int atmel_tc_count_read(struct counter_device *counter, + struct counter_count *count, + unsigned long *val) +{ + struct atmel_tc_data *const priv = counter->priv; + u32 cnt; + + regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt); + *val = cnt; + + return 0; +} + +static struct counter_count atmel_tc_count = { + .id = 0, + .name = "Timer Counter", + .functions_list = atmel_tc_count_functions, + .num_functions = ARRAY_SIZE(atmel_tc_count_functions), + .synapses = atmel_tc_count_synapses, + .num_synapses = ARRAY_SIZE(atmel_tc_count_synapses), +}; + +static struct counter_ops atmel_tc_ops = { + .signal_read = atmel_tc_count_signal_read, + .count_read = atmel_tc_count_read, + .count_write = NULL, + .function_get = atmel_tc_count_function_get, + .function_set = atmel_tc_count_function_set, + .action_get = atmel_tc_count_action_get, + .action_set = atmel_tc_count_action_set +}; + +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 int atmel_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 atmel_tc_data *priv; + char clk_name[] = "t0_clk"; + struct regmap *regmap; + struct clk *clk[3]; + int channel; + int ret, i; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + 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(priv->regmap)) + return PTR_ERR(priv->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; + + clk_name[1] += 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; + + dev_info(&pdev->dev, + "Initialized capture mode on channel %d\n", + channel); + } + + priv->tc_cfg = tcb_config; + priv->regmap = regmap; + priv->counter.name = dev_name(&pdev->dev); + priv->counter.parent = &pdev->dev; + priv->counter.ops = &atmel_tc_ops; + priv->counter.num_counts = 1; + priv->counter.counts = &atmel_tc_count; + priv->counter.num_signals = ARRAY_SIZE(atmel_tc_count_signals); + priv->counter.signals = atmel_tc_count_signals; + priv->counter.priv = priv; + + ret = devm_counter_register(&pdev->dev, &priv->counter); + if (ret < 0) { + for (i = 0; i < priv->num_channels; i++) + clk_disable_unprepare(clk[i]); + return ret; + } + + return 0; +} + +static const struct of_device_id atmel_tc_dt_ids[] = { + { .compatible = "atmel,tcb-capture", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, atmel_tc_dt_ids); + +static struct platform_driver atmel_tc_driver = { + .probe = atmel_tc_probe, + .driver = { + .name = "atmel-tcb-capture", + .of_match_table = atmel_tc_dt_ids, + }, +}; +module_platform_driver(atmel_tc_driver); + +MODULE_AUTHOR("Kamel Bouhara "); +MODULE_DESCRIPTION("Atmel TCB Capture driver"); +MODULE_LICENSE("GPL v2");