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![Robert Hancock](/assets/img/avatar_default.png)
[ Upstream commitabaca3179b
] If the pps-gpio driver was probed prior to the GPIO device it uses, the devm_gpiod_get call returned an -EPROBE_DEFER error, but pps_gpio_probe replaced that error code with -EINVAL, causing the pps-gpio probe to fail and not be retried later. Propagate the error return value so that deferred probe works properly. Fixes:161520451d
(pps: new client driver using GPIO) Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Robert Hancock <robert.hancock@calian.com> Signed-off-by: Rodolfo Giometti <giometti@enneenne.com> Link: https://lore.kernel.org/r/20220112205214.2060954-1-robert.hancock@calian.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
255 lines
6.8 KiB
C
255 lines
6.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* pps-gpio.c -- PPS client driver using GPIO
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*
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* Copyright (C) 2010 Ricardo Martins <rasm@fe.up.pt>
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* Copyright (C) 2011 James Nuss <jamesnuss@nanometrics.ca>
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*/
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#define PPS_GPIO_NAME "pps-gpio"
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#define pr_fmt(fmt) PPS_GPIO_NAME ": " fmt
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/interrupt.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/pps_kernel.h>
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#include <linux/gpio/consumer.h>
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#include <linux/list.h>
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#include <linux/property.h>
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#include <linux/timer.h>
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#include <linux/jiffies.h>
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/* Info for each registered platform device */
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struct pps_gpio_device_data {
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int irq; /* IRQ used as PPS source */
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struct pps_device *pps; /* PPS source device */
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struct pps_source_info info; /* PPS source information */
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struct gpio_desc *gpio_pin; /* GPIO port descriptors */
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struct gpio_desc *echo_pin;
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struct timer_list echo_timer; /* timer to reset echo active state */
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bool assert_falling_edge;
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bool capture_clear;
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unsigned int echo_active_ms; /* PPS echo active duration */
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unsigned long echo_timeout; /* timer timeout value in jiffies */
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};
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/*
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* Report the PPS event
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*/
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static irqreturn_t pps_gpio_irq_handler(int irq, void *data)
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{
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const struct pps_gpio_device_data *info;
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struct pps_event_time ts;
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int rising_edge;
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/* Get the time stamp first */
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pps_get_ts(&ts);
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info = data;
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rising_edge = gpiod_get_value(info->gpio_pin);
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if ((rising_edge && !info->assert_falling_edge) ||
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(!rising_edge && info->assert_falling_edge))
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pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data);
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else if (info->capture_clear &&
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((rising_edge && info->assert_falling_edge) ||
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(!rising_edge && !info->assert_falling_edge)))
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pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data);
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return IRQ_HANDLED;
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}
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/* This function will only be called when an ECHO GPIO is defined */
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static void pps_gpio_echo(struct pps_device *pps, int event, void *data)
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{
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/* add_timer() needs to write into info->echo_timer */
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struct pps_gpio_device_data *info = data;
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switch (event) {
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case PPS_CAPTUREASSERT:
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if (pps->params.mode & PPS_ECHOASSERT)
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gpiod_set_value(info->echo_pin, 1);
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break;
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case PPS_CAPTURECLEAR:
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if (pps->params.mode & PPS_ECHOCLEAR)
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gpiod_set_value(info->echo_pin, 1);
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break;
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}
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/* fire the timer */
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if (info->pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) {
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info->echo_timer.expires = jiffies + info->echo_timeout;
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add_timer(&info->echo_timer);
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}
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}
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/* Timer callback to reset the echo pin to the inactive state */
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static void pps_gpio_echo_timer_callback(struct timer_list *t)
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{
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const struct pps_gpio_device_data *info;
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info = from_timer(info, t, echo_timer);
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gpiod_set_value(info->echo_pin, 0);
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}
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static int pps_gpio_setup(struct device *dev)
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{
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struct pps_gpio_device_data *data = dev_get_drvdata(dev);
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int ret;
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u32 value;
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data->gpio_pin = devm_gpiod_get(dev, NULL, GPIOD_IN);
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if (IS_ERR(data->gpio_pin))
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return dev_err_probe(dev, PTR_ERR(data->gpio_pin),
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"failed to request PPS GPIO\n");
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data->assert_falling_edge =
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device_property_read_bool(dev, "assert-falling-edge");
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data->echo_pin = devm_gpiod_get_optional(dev, "echo", GPIOD_OUT_LOW);
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if (IS_ERR(data->echo_pin))
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return dev_err_probe(dev, PTR_ERR(data->echo_pin),
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"failed to request ECHO GPIO\n");
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if (!data->echo_pin)
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return 0;
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ret = device_property_read_u32(dev, "echo-active-ms", &value);
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if (ret) {
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dev_err(dev, "failed to get echo-active-ms from FW\n");
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return ret;
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}
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/* sanity check on echo_active_ms */
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if (!value || value > 999) {
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dev_err(dev, "echo-active-ms: %u - bad value from FW\n", value);
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return -EINVAL;
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}
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data->echo_active_ms = value;
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return 0;
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}
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static unsigned long
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get_irqf_trigger_flags(const struct pps_gpio_device_data *data)
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{
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unsigned long flags = data->assert_falling_edge ?
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IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
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if (data->capture_clear) {
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flags |= ((flags & IRQF_TRIGGER_RISING) ?
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IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING);
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}
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return flags;
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}
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static int pps_gpio_probe(struct platform_device *pdev)
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{
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struct pps_gpio_device_data *data;
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struct device *dev = &pdev->dev;
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int ret;
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int pps_default_params;
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/* allocate space for device info */
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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dev_set_drvdata(dev, data);
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/* GPIO setup */
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ret = pps_gpio_setup(dev);
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if (ret)
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return ret;
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/* IRQ setup */
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ret = gpiod_to_irq(data->gpio_pin);
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if (ret < 0) {
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dev_err(dev, "failed to map GPIO to IRQ: %d\n", ret);
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return -EINVAL;
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}
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data->irq = ret;
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/* initialize PPS specific parts of the bookkeeping data structure. */
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data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |
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PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC;
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if (data->capture_clear)
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data->info.mode |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR |
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PPS_ECHOCLEAR;
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data->info.owner = THIS_MODULE;
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snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d",
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pdev->name, pdev->id);
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if (data->echo_pin) {
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data->info.echo = pps_gpio_echo;
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data->echo_timeout = msecs_to_jiffies(data->echo_active_ms);
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timer_setup(&data->echo_timer, pps_gpio_echo_timer_callback, 0);
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}
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/* register PPS source */
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pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT;
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if (data->capture_clear)
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pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR;
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data->pps = pps_register_source(&data->info, pps_default_params);
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if (IS_ERR(data->pps)) {
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dev_err(dev, "failed to register IRQ %d as PPS source\n",
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data->irq);
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return PTR_ERR(data->pps);
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}
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/* register IRQ interrupt handler */
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ret = devm_request_irq(dev, data->irq, pps_gpio_irq_handler,
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get_irqf_trigger_flags(data), data->info.name, data);
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if (ret) {
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pps_unregister_source(data->pps);
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dev_err(dev, "failed to acquire IRQ %d\n", data->irq);
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return -EINVAL;
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}
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dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n",
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data->irq);
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return 0;
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}
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static int pps_gpio_remove(struct platform_device *pdev)
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{
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struct pps_gpio_device_data *data = platform_get_drvdata(pdev);
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pps_unregister_source(data->pps);
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del_timer_sync(&data->echo_timer);
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/* reset echo pin in any case */
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gpiod_set_value(data->echo_pin, 0);
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dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);
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return 0;
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}
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static const struct of_device_id pps_gpio_dt_ids[] = {
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{ .compatible = "pps-gpio", },
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, pps_gpio_dt_ids);
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static struct platform_driver pps_gpio_driver = {
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.probe = pps_gpio_probe,
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.remove = pps_gpio_remove,
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.driver = {
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.name = PPS_GPIO_NAME,
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.of_match_table = pps_gpio_dt_ids,
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},
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};
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module_platform_driver(pps_gpio_driver);
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MODULE_AUTHOR("Ricardo Martins <rasm@fe.up.pt>");
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MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>");
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MODULE_DESCRIPTION("Use GPIO pin as PPS source");
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MODULE_LICENSE("GPL");
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MODULE_VERSION("1.2.0");
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