Commit c5dbcf8b authored by Jan Luebbe's avatar Jan Luebbe Committed by Linus Torvalds
Browse files

pps-gpio: add device-tree binding and support 



Instead of allocating a struct pps_gpio_platform_data in the DT case,
store the necessary information in struct pps_gpio_device_data itself.
This avoids an additional allocation and the ifdef.  It also gets rid of
some indirection.

Also use dev_err instead of pr_err in the changed code.

Signed-off-by: default avatarJan Luebbe <jlu@pengutronix.de>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarRodolfo Giometti <giometti@enneenne.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 05212be3

Documentation/devicetree/bindings/pps/pps-gpio.txt

0 → 100644
+20 −0
Original line number Diff line number Diff line 
Device-Tree Bindings for a PPS Signal on GPIO



These properties describe a PPS (pulse-per-second) signal connected to

a GPIO pin.



Required properties:

- compatible: should be "pps-gpio"

- gpios: one PPS GPIO in the format described by ../gpio/gpio.txt



Optional properties:

- assert-falling-edge: when present, assert is indicated by a falling edge

                       (instead of by a rising edge)



Example:

	pps {

		compatible = "pps-gpio";

		gpios = <&gpio2 6 0>;



		assert-falling-edge;

	};

drivers/pps/clients/pps-gpio.c

+73 −54
Original line number Diff line number Diff line
@@ -33,13 +33,17 @@ 
#include <linux/pps-gpio.h>

#include <linux/gpio.h>

#include <linux/list.h>

#include <linux/of_device.h>

#include <linux/of_gpio.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 */

	const struct pps_gpio_platform_data *pdata;

	bool assert_falling_edge;

	bool capture_clear;

	unsigned int gpio_pin;

};



/*
@@ -57,45 +61,25 @@ static irqreturn_t pps_gpio_irq_handler(int irq, void *data) 


	info = data;



	rising_edge = gpio_get_value(info->pdata->gpio_pin);

	if ((rising_edge && !info->pdata->assert_falling_edge) ||

			(!rising_edge && info->pdata->assert_falling_edge))

	rising_edge = gpio_get_value(info->gpio_pin);

	if ((rising_edge && !info->assert_falling_edge) ||

			(!rising_edge && info->assert_falling_edge))

		pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL);

	else if (info->pdata->capture_clear &&

			((rising_edge && info->pdata->assert_falling_edge) ||

			 (!rising_edge && !info->pdata->assert_falling_edge)))

	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);



	return IRQ_HANDLED;

}



static int pps_gpio_setup(struct platform_device *pdev)

{

	int ret;

	const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data;



	ret = devm_gpio_request(&pdev->dev, pdata->gpio_pin, pdata->gpio_label);

	if (ret) {

		pr_warning("failed to request GPIO %u\n", pdata->gpio_pin);

		return -EINVAL;

	}



	ret = gpio_direction_input(pdata->gpio_pin);

	if (ret) {

		pr_warning("failed to set pin direction\n");

		return -EINVAL;

	}



	return 0;

}



static unsigned long

get_irqf_trigger_flags(const struct pps_gpio_platform_data *pdata)

get_irqf_trigger_flags(const struct pps_gpio_device_data *data)

{

	unsigned long flags = pdata->assert_falling_edge ?

	unsigned long flags = data->assert_falling_edge ?

		IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;



	if (pdata->capture_clear) {

	if (data->capture_clear) {

		flags |= ((flags & IRQF_TRIGGER_RISING) ?

				IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING);

	}
@@ -106,34 +90,63 @@ get_irqf_trigger_flags(const struct pps_gpio_platform_data *pdata) 
static int pps_gpio_probe(struct platform_device *pdev)

{

	struct pps_gpio_device_data *data;

	int irq;

	const char *gpio_label;

	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);

	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;

	}



	/* GPIO setup */

	ret = pps_gpio_setup(pdev);

	if (ret)

	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);

		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 */

	irq = gpio_to_irq(pdata->gpio_pin);

	if (irq < 0) {

		pr_err("failed to map GPIO to IRQ: %d\n", irq);

	ret = gpio_to_irq(data->gpio_pin);

	if (ret < 0) {

		dev_err(&pdev->dev, "failed to map GPIO to IRQ: %d\n", ret);

		return -EINVAL;

	}



	/* allocate space for device info */

	data = devm_kzalloc(&pdev->dev, sizeof(struct pps_gpio_device_data),

			    GFP_KERNEL);

	if (data == NULL)

		return -ENOMEM;

	data->irq = ret;



	/* initialize PPS specific parts of the bookkeeping data structure. */

	data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT |

		PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC;

	if (pdata->capture_clear)

	if (data->capture_clear)

		data->info.mode |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR |

			PPS_ECHOCLEAR;

	data->info.owner = THIS_MODULE;
@@ -142,28 +155,27 @@ static int pps_gpio_probe(struct platform_device *pdev) 


	/* register PPS source */

	pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT;

	if (pdata->capture_clear)

	if (data->capture_clear)

		pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR;

	data->pps = pps_register_source(&data->info, pps_default_params);

	if (data->pps == NULL) {

		pr_err("failed to register IRQ %d as PPS source\n", irq);

		dev_err(&pdev->dev, "failed to register IRQ %d as PPS source\n",

			data->irq);

		return -EINVAL;

	}



	data->irq = irq;

	data->pdata = pdata;



	/* register IRQ interrupt handler */

	ret = devm_request_irq(&pdev->dev, irq, pps_gpio_irq_handler,

			get_irqf_trigger_flags(pdata), data->info.name, data);

	ret = devm_request_irq(&pdev->dev, data->irq, pps_gpio_irq_handler,

			get_irqf_trigger_flags(data), data->info.name, data);

	if (ret) {

		pps_unregister_source(data->pps);

		pr_err("failed to acquire IRQ %d\n", irq);

		dev_err(&pdev->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", irq);

	dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n",

		 data->irq);



	return 0;

}
@@ -174,16 +186,23 @@ static int pps_gpio_remove(struct platform_device *pdev) 


	platform_set_drvdata(pdev, NULL);

	pps_unregister_source(data->pps);

	pr_info("removed IRQ %d as PPS source\n", data->irq);

	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[] = {

	{ .compatible = "pps-gpio", },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, pps_gpio_dt_ids);



static struct platform_driver pps_gpio_driver = {

	.probe		= pps_gpio_probe,

	.remove		= pps_gpio_remove,

	.driver		= {

		.name	= PPS_GPIO_NAME,

		.owner	= THIS_MODULE

		.owner	= THIS_MODULE,

		.of_match_table	= of_match_ptr(pps_gpio_dt_ids),

	},

};

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