1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * pps-gpio.c -- PPS client driver using GPIO
9 #define PPS_GPIO_NAME "pps-gpio"
33 	struct timer_list echo_timer;	/* timer to reset echo active state */
36 	unsigned int echo_active_ms;	/* PPS echo active duration */
55 	rising_edge = gpiod_get_value(info->gpio_pin);  in pps_gpio_irq_handler()
56 	if ((rising_edge && !info->assert_falling_edge) ||  in pps_gpio_irq_handler()
57 			(!rising_edge && info->assert_falling_edge))  in pps_gpio_irq_handler()
58 		pps_event(info->pps, &ts, PPS_CAPTUREASSERT, data);  in pps_gpio_irq_handler()
59 	else if (info->capture_clear &&  in pps_gpio_irq_handler()
60 			((rising_edge && info->assert_falling_edge) ||  in pps_gpio_irq_handler()
61 			(!rising_edge && !info->assert_falling_edge)))  in pps_gpio_irq_handler()
62 		pps_event(info->pps, &ts, PPS_CAPTURECLEAR, data);  in pps_gpio_irq_handler()
67 /* This function will only be called when an ECHO GPIO is defined */
70 	/* add_timer() needs to write into info->echo_timer */  in pps_gpio_echo()
75 		if (pps->params.mode & PPS_ECHOASSERT)  in pps_gpio_echo()
76 			gpiod_set_value(info->echo_pin, 1);  in pps_gpio_echo()
80 		if (pps->params.mode & PPS_ECHOCLEAR)  in pps_gpio_echo()
81 			gpiod_set_value(info->echo_pin, 1);  in pps_gpio_echo()
86 	if (info->pps->params.mode & (PPS_ECHOASSERT | PPS_ECHOCLEAR)) {  in pps_gpio_echo()
87 		info->echo_timer.expires = jiffies + info->echo_timeout;  in pps_gpio_echo()
88 		add_timer(&info->echo_timer);  in pps_gpio_echo()
92 /* Timer callback to reset the echo pin to the inactive state */
99 	gpiod_set_value(info->echo_pin, 0);  in pps_gpio_echo_timer_callback()
108 	data->gpio_pin = devm_gpiod_get(dev, NULL, GPIOD_IN);  in pps_gpio_setup()
109 	if (IS_ERR(data->gpio_pin))  in pps_gpio_setup()
110 		return dev_err_probe(dev, PTR_ERR(data->gpio_pin),  in pps_gpio_setup()
113 	data->assert_falling_edge =  in pps_gpio_setup()
114 		device_property_read_bool(dev, "assert-falling-edge");  in pps_gpio_setup()
116 	data->echo_pin = devm_gpiod_get_optional(dev, "echo", GPIOD_OUT_LOW);  in pps_gpio_setup()
117 	if (IS_ERR(data->echo_pin))  in pps_gpio_setup()
118 		return dev_err_probe(dev, PTR_ERR(data->echo_pin),  in pps_gpio_setup()
119 				     "failed to request ECHO GPIO\n");  in pps_gpio_setup()
121 	if (!data->echo_pin)  in pps_gpio_setup()
124 	ret = device_property_read_u32(dev, "echo-active-ms", &value);  in pps_gpio_setup()
126 		dev_err(dev, "failed to get echo-active-ms from FW\n");  in pps_gpio_setup()
132 		dev_err(dev, "echo-active-ms: %u - bad value from FW\n", value);  in pps_gpio_setup()
133 		return -EINVAL;  in pps_gpio_setup()
136 	data->echo_active_ms = value;  in pps_gpio_setup()
144 	unsigned long flags = data->assert_falling_edge ?  in get_irqf_trigger_flags()
147 	if (data->capture_clear) {  in get_irqf_trigger_flags()
158 	struct device *dev = &pdev->dev;  in pps_gpio_probe()
165 		return -ENOMEM;  in pps_gpio_probe()
175 	ret = gpiod_to_irq(data->gpio_pin);  in pps_gpio_probe()
178 		return -EINVAL;  in pps_gpio_probe()
180 	data->irq = ret;  in pps_gpio_probe()
183 	data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |  in pps_gpio_probe()
185 	if (data->capture_clear)  in pps_gpio_probe()
186 		data->info.mode |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR |  in pps_gpio_probe()
188 	data->info.owner = THIS_MODULE;  in pps_gpio_probe()
189 	snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d",  in pps_gpio_probe()
190 		 pdev->name, pdev->id);  in pps_gpio_probe()
191 	if (data->echo_pin) {  in pps_gpio_probe()
192 		data->info.echo = pps_gpio_echo;  in pps_gpio_probe()
193 		data->echo_timeout = msecs_to_jiffies(data->echo_active_ms);  in pps_gpio_probe()
194 		timer_setup(&data->echo_timer, pps_gpio_echo_timer_callback, 0);  in pps_gpio_probe()
199 	if (data->capture_clear)  in pps_gpio_probe()
201 	data->pps = pps_register_source(&data->info, pps_default_params);  in pps_gpio_probe()
202 	if (IS_ERR(data->pps)) {  in pps_gpio_probe()
204 			data->irq);  in pps_gpio_probe()
205 		return PTR_ERR(data->pps);  in pps_gpio_probe()
209 	ret = devm_request_irq(dev, data->irq, pps_gpio_irq_handler,  in pps_gpio_probe()
210 			get_irqf_trigger_flags(data), data->info.name, data);  in pps_gpio_probe()
212 		pps_unregister_source(data->pps);  in pps_gpio_probe()
213 		dev_err(dev, "failed to acquire IRQ %d\n", data->irq);  in pps_gpio_probe()
214 		return -EINVAL;  in pps_gpio_probe()
217 	dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n",  in pps_gpio_probe()
218 		 data->irq);  in pps_gpio_probe()
227 	pps_unregister_source(data->pps);  in pps_gpio_remove()
228 	del_timer_sync(&data->echo_timer);  in pps_gpio_remove()
229 	/* reset echo pin in any case */  in pps_gpio_remove()
230 	gpiod_set_value(data->echo_pin, 0);  in pps_gpio_remove()
231 	dev_info(&pdev->dev, "removed IRQ %d as PPS source\n", data->irq);  in pps_gpio_remove()
235 	{ .compatible = "pps-gpio", },