From patchwork Wed Apr 15 13:04:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamel BOUHARA X-Patchwork-Id: 11491203 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 2BADD912 for ; Wed, 15 Apr 2020 13:05:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E2EF20737 for ; Wed, 15 Apr 2020 13:05:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503610AbgDONFw (ORCPT ); Wed, 15 Apr 2020 09:05:52 -0400 Received: from relay10.mail.gandi.net ([217.70.178.230]:42307 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2505908AbgDONFN (ORCPT ); Wed, 15 Apr 2020 09:05:13 -0400 Received: from localhost (unknown [78.193.40.249]) (Authenticated sender: kamel.bouhara@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id DD7F8240012; Wed, 15 Apr 2020 13:05:09 +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 v3 3/3] counter: Add microchip TCB capture counter Date: Wed, 15 Apr 2020 15:04:55 +0200 Message-Id: <20200415130455.2222019-4-kamel.bouhara@bootlin.com> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200415130455.2222019-1-kamel.bouhara@bootlin.com> References: <20200415130455.2222019-1-kamel.bouhara@bootlin.com> MIME-Version: 1.0 Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org This drivers allows to use the capture mode of the Timer Counter Block hardware block available in Microchip 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 Signed-off-by: William Breathitt Gray --- Changes from v3: - Updated the brand name: s/atmel/microchip/. - Removed useless blank line - Added an explicit clock removing path using devm_add_action_or_reset Changes from v2: - Updated return code to -EINVAL when user is requesting qdec mode on a counter device not supporting it. - Added an error case returning -EINVAL when action edge is performed in qdec mode. - Removed no need to explicity setting ops to NULL from static struct as it is the default value. - Changed confusing code by using snprintf for the sake of clarity. - Changed code to use ARRAY_SIZE so that future reviewers will know that num_counts matches what's in the atmel_tc_count array without having to check so themselves. drivers/counter/Kconfig | 11 + drivers/counter/Makefile | 1 + drivers/counter/microchip-tcb-capture.c | 397 ++++++++++++++++++++++++ 3 files changed, 409 insertions(+) create mode 100644 drivers/counter/microchip-tcb-capture.c diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig index c80fa76bb531..2de53ab0dd25 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 MICROCHIP_TCB_CAPTURE + tristate "Microchip Timer Counter Capture driver" + depends on HAS_IOMEM && OF + select REGMAP_MMIO + help + Select this option to enable the Microchip Timer Counter Block + capture driver. + + To compile this driver as a module, choose M here: the + module will be called microchip-tcb-capture. + endif # COUNTER diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile index 55142d1f4c43..0a393f71e481 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_MICROCHIP_TCB_CAPTURE) += microchip-tcb-capture.o diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c new file mode 100644 index 000000000000..f7b7743ddb94 --- /dev/null +++ b/drivers/counter/microchip-tcb-capture.c @@ -0,0 +1,397 @@ +// SPDX-License-Identifier: GPL-2.0-only +/** + * Copyright (C) 2020 Microchip + * + * 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 mchp_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 mchp_tc_count_function { + MCHP_TC_FUNCTION_INCREASE, + MCHP_TC_FUNCTION_QUADRATURE, +}; + +static enum counter_count_function mchp_tc_count_functions[] = { + [MCHP_TC_FUNCTION_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE, + [MCHP_TC_FUNCTION_QUADRATURE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4, +}; + +enum mchp_tc_synapse_action { + MCHP_TC_SYNAPSE_ACTION_NONE = 0, + MCHP_TC_SYNAPSE_ACTION_RISING_EDGE, + MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE, + MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE +}; + +static enum counter_synapse_action mchp_tc_synapse_actions[] = { + [MCHP_TC_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE, + [MCHP_TC_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE, + [MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE, + [MCHP_TC_SYNAPSE_ACTION_BOTH_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_get(struct counter_device *counter, + struct counter_count *count, + size_t *function) +{ + struct mchp_tc_data *const priv = counter->priv; + + if (priv->qdec_mode) + *function = MCHP_TC_FUNCTION_QUADRATURE; + else + *function = MCHP_TC_FUNCTION_INCREASE; + + return 0; +} + +static int mchp_tc_count_function_set(struct counter_device *counter, + struct counter_count *count, + size_t function) +{ + struct mchp_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 MCHP_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 MCHP_TC_FUNCTION_QUADRATURE: + 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; + } + + 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_value *val) +{ + struct mchp_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 mchp_tc_count_action_get(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + size_t *action) +{ + struct mchp_tc_data *const priv = counter->priv; + u32 cmr; + + regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); + + *action = MCHP_TC_SYNAPSE_ACTION_NONE; + + if (cmr & ATMEL_TC_ETRGEDG_NONE) + *action = MCHP_TC_SYNAPSE_ACTION_NONE; + else if (cmr & ATMEL_TC_ETRGEDG_RISING) + *action = MCHP_TC_SYNAPSE_ACTION_RISING_EDGE; + else if (cmr & ATMEL_TC_ETRGEDG_FALLING) + *action = MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE; + else if (cmr & ATMEL_TC_ETRGEDG_BOTH) + *action = MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE; + + return 0; +} + +static int mchp_tc_count_action_set(struct counter_device *counter, + struct counter_count *count, + struct counter_synapse *synapse, + size_t action) +{ + struct mchp_tc_data *const priv = counter->priv; + u32 edge = ATMEL_TC_ETRGEDG_NONE; + + /* QDEC mode is rising edge only */ + if (priv->qdec_mode) + return -EINVAL; + + switch (action) { + case MCHP_TC_SYNAPSE_ACTION_NONE: + edge = ATMEL_TC_ETRGEDG_NONE; + break; + case MCHP_TC_SYNAPSE_ACTION_RISING_EDGE: + edge = ATMEL_TC_ETRGEDG_RISING; + break; + case MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE: + edge = ATMEL_TC_ETRGEDG_FALLING; + break; + case MCHP_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 mchp_tc_count_read(struct counter_device *counter, + struct counter_count *count, + unsigned long *val) +{ + struct mchp_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 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 struct counter_ops mchp_tc_ops = { + .signal_read = mchp_tc_count_signal_read, + .count_read = mchp_tc_count_read, + .function_get = mchp_tc_count_function_get, + .function_set = mchp_tc_count_function_set, + .action_get = mchp_tc_count_action_get, + .action_set = mchp_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 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 mchp_tc_data *priv; + char clk_name[7]; + 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; + + 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; + priv->counter.name = dev_name(&pdev->dev); + priv->counter.parent = &pdev->dev; + priv->counter.ops = &mchp_tc_ops; + priv->counter.num_counts = ARRAY_SIZE(mchp_tc_counts); + priv->counter.counts = mchp_tc_counts; + priv->counter.num_signals = ARRAY_SIZE(mchp_tc_count_signals); + priv->counter.signals = mchp_tc_count_signals; + priv->counter.priv = priv; + + return devm_counter_register(&pdev->dev, &priv->counter); +} + +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 "); +MODULE_DESCRIPTION("Microchip TCB Capture driver"); +MODULE_LICENSE("GPL v2");