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path: root/drivers/pps/clients/pps-gpio.c
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Diffstat (limited to 'drivers/pps/clients/pps-gpio.c')
-rw-r--r--drivers/pps/clients/pps-gpio.c187
1 files changed, 117 insertions, 70 deletions
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
index dd5d1103e02b..935da68610c7 100644
--- a/drivers/pps/clients/pps-gpio.c
+++ b/drivers/pps/clients/pps-gpio.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* pps-gpio.c -- PPS client driver using GPIO
*
- *
* Copyright (C) 2010 Ricardo Martins <rasm@fe.up.pt>
* Copyright (C) 2011 James Nuss <jamesnuss@nanometrics.ca>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define PPS_GPIO_NAME "pps-gpio"
@@ -26,24 +12,29 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pps_kernel.h>
-#include <linux/pps-gpio.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/list.h>
-#include <linux/of_device.h>
-#include <linux/of_gpio.h>
+#include <linux/property.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
/* Info for each registered platform device */
struct pps_gpio_device_data {
int irq; /* IRQ used as PPS source */
struct pps_device *pps; /* PPS source device */
struct pps_source_info info; /* PPS source information */
+ struct gpio_desc *gpio_pin; /* GPIO port descriptors */
+ struct gpio_desc *echo_pin;
+ struct timer_list echo_timer; /* timer to reset echo active state */
bool assert_falling_edge;
bool capture_clear;
- unsigned int gpio_pin;
+ unsigned int echo_active_ms; /* PPS echo active duration */
+ unsigned long echo_timeout; /* timer timeout value in jiffies */
};
/*
@@ -61,18 +52,96 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data)
info = data;
- rising_edge = gpio_get_value(info->gpio_pin);
+ /* Small trick to bypass the check on edge's direction when capture_clear is unset */
+ rising_edge = info->capture_clear ?
+ gpiod_get_value(info->gpio_pin) : !info->assert_falling_edge;
if ((rising_edge && !info->assert_falling_edge) ||
(!rising_edge && info->assert_falling_edge))
- pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL);
+ pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data);
else if (info->capture_clear &&
((rising_edge && info->assert_falling_edge) ||
- (!rising_edge && !info->assert_falling_edge)))
- pps_event(info->pps, &ts, PPS_CAPTURECLEAR, NULL);
+ (!rising_edge && !info->assert_falling_edge)))
+ pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data);
+ else
+ dev_warn_ratelimited(&info->pps->dev, "IRQ did not trigger any PPS event\n");
return IRQ_HANDLED;
}
+/* This function will only be called when an ECHO GPIO is defined */
+static void pps_gpio_echo(struct pps_device *pps, int event, void *data)
+{
+ /* add_timer() needs to write into info->echo_timer */
+ struct pps_gpio_device_data *info = data;
+
+ switch (event) {
+ case PPS_CAPTUREASSERT:
+ if (pps->params.mode & PPS_ECHOASSERT)
+ gpiod_set_value(info->echo_pin, 1);
+ break;
+
+ case PPS_CAPTURECLEAR:
+ if (pps->params.mode & PPS_ECHOCLEAR)
+ gpiod_set_value(info->echo_pin, 1);
+ break;
+ }
+
+ /* fire the timer */
+ if (info->pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) {
+ info->echo_timer.expires = jiffies + info->echo_timeout;
+ add_timer(&info->echo_timer);
+ }
+}
+
+/* Timer callback to reset the echo pin to the inactive state */
+static void pps_gpio_echo_timer_callback(struct timer_list *t)
+{
+ const struct pps_gpio_device_data *info;
+
+ info = timer_container_of(info, t, echo_timer);
+
+ gpiod_set_value(info->echo_pin, 0);
+}
+
+static int pps_gpio_setup(struct device *dev)
+{
+ struct pps_gpio_device_data *data = dev_get_drvdata(dev);
+ int ret;
+ u32 value;
+
+ data->gpio_pin = devm_gpiod_get(dev, NULL, GPIOD_IN);
+ if (IS_ERR(data->gpio_pin))
+ return dev_err_probe(dev, PTR_ERR(data->gpio_pin),
+ "failed to request PPS GPIO\n");
+
+ data->assert_falling_edge =
+ device_property_read_bool(dev, "assert-falling-edge");
+
+ data->echo_pin = devm_gpiod_get_optional(dev, "echo", GPIOD_OUT_LOW);
+ if (IS_ERR(data->echo_pin))
+ return dev_err_probe(dev, PTR_ERR(data->echo_pin),
+ "failed to request ECHO GPIO\n");
+
+ if (!data->echo_pin)
+ return 0;
+
+ ret = device_property_read_u32(dev, "echo-active-ms", &value);
+ if (ret) {
+ dev_err(dev, "failed to get echo-active-ms from FW\n");
+ return ret;
+ }
+
+ /* sanity check on echo_active_ms */
+ if (!value || value > 999) {
+ dev_err(dev, "echo-active-ms: %u - bad value from FW\n", value);
+ return -EINVAL;
+ }
+
+ data->echo_active_ms = value;
+
+ return 0;
+}
+
static unsigned long
get_irqf_trigger_flags(const struct pps_gpio_device_data *data)
{
@@ -90,55 +159,26 @@ get_irqf_trigger_flags(const struct pps_gpio_device_data *data)
static int pps_gpio_probe(struct platform_device *pdev)
{
struct pps_gpio_device_data *data;
- const char *gpio_label;
+ struct device *dev = &pdev->dev;
int ret;
int pps_default_params;
- const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data;
- struct device_node *np = pdev->dev.of_node;
/* allocate space for device info */
- data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data),
- GFP_KERNEL);
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
- if (pdata) {
- data->gpio_pin = pdata->gpio_pin;
- gpio_label = pdata->gpio_label;
-
- data->assert_falling_edge = pdata->assert_falling_edge;
- data->capture_clear = pdata->capture_clear;
- } else {
- ret = of_get_gpio(np, 0);
- if (ret < 0) {
- dev_err(&pdev->dev, "failed to get GPIO from device tree\n");
- return ret;
- }
- data->gpio_pin = ret;
- gpio_label = PPS_GPIO_NAME;
-
- if (of_get_property(np, "assert-falling-edge", NULL))
- data->assert_falling_edge = true;
- }
+ dev_set_drvdata(dev, data);
/* GPIO setup */
- ret = devm_gpio_request(&pdev->dev, data->gpio_pin, gpio_label);
- if (ret) {
- dev_err(&pdev->dev, "failed to request GPIO %u\n",
- data->gpio_pin);
+ ret = pps_gpio_setup(dev);
+ if (ret)
return ret;
- }
-
- ret = gpio_direction_input(data->gpio_pin);
- if (ret) {
- dev_err(&pdev->dev, "failed to set pin direction\n");
- return -EINVAL;
- }
/* IRQ setup */
- ret = gpio_to_irq(data->gpio_pin);
+ ret = gpiod_to_irq(data->gpio_pin);
if (ret < 0) {
- dev_err(&pdev->dev, "failed to map GPIO to IRQ: %d\n", ret);
+ dev_err(dev, "failed to map GPIO to IRQ: %d\n", ret);
return -EINVAL;
}
data->irq = ret;
@@ -152,6 +192,11 @@ static int pps_gpio_probe(struct platform_device *pdev)
data->info.owner = THIS_MODULE;
snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d",
pdev->name, pdev->id);
+ if (data->echo_pin) {
+ data->info.echo = pps_gpio_echo;
+ data->echo_timeout = msecs_to_jiffies(data->echo_active_ms);
+ timer_setup(&data->echo_timer, pps_gpio_echo_timer_callback, 0);
+ }
/* register PPS source */
pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT;
@@ -159,34 +204,36 @@ static int pps_gpio_probe(struct platform_device *pdev)
pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR;
data->pps = pps_register_source(&data->info, pps_default_params);
if (IS_ERR(data->pps)) {
- dev_err(&pdev->dev, "failed to register IRQ %d as PPS source\n",
+ dev_err(dev, "failed to register IRQ %d as PPS source\n",
data->irq);
return PTR_ERR(data->pps);
}
/* register IRQ interrupt handler */
- ret = devm_request_irq(&pdev->dev, data->irq, pps_gpio_irq_handler,
- get_irqf_trigger_flags(data), data->info.name, data);
+ ret = request_irq(data->irq, pps_gpio_irq_handler,
+ get_irqf_trigger_flags(data), data->info.name, data);
if (ret) {
pps_unregister_source(data->pps);
- dev_err(&pdev->dev, "failed to acquire IRQ %d\n", data->irq);
+ dev_err(dev, "failed to acquire IRQ %d\n", data->irq);
return -EINVAL;
}
- platform_set_drvdata(pdev, data);
- dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n",
- data->irq);
+ dev_dbg(&data->pps->dev, "Registered IRQ %d as PPS source\n",
+ data->irq);
return 0;
}
-static int pps_gpio_remove(struct platform_device *pdev)
+static void pps_gpio_remove(struct platform_device *pdev)
{
struct pps_gpio_device_data *data = platform_get_drvdata(pdev);
+ free_irq(data->irq, data);
pps_unregister_source(data->pps);
+ timer_delete_sync(&data->echo_timer);
+ /* reset echo pin in any case */
+ gpiod_set_value(data->echo_pin, 0);
dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);
- return 0;
}
static const struct of_device_id pps_gpio_dt_ids[] = {
@@ -209,4 +256,4 @@ MODULE_AUTHOR("Ricardo Martins <rasm@fe.up.pt>");
MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>");
MODULE_DESCRIPTION("Use GPIO pin as PPS source");
MODULE_LICENSE("GPL");
-MODULE_VERSION("1.0.0");
+MODULE_VERSION("1.2.0");
generated by cgit (git 2.34.1) at 2025-12-24 22:50:44 +0000