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pps-gpio: add device-tree binding and support

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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: Jan Luebbe <jlu@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rodolfo Giometti <giometti@enneenne.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Luebbe 2013-07-03 15:09:12 -07:00 committed by Linus Torvalds
parent 05212be363
commit c5dbcf8b70
2 changed files with 97 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
Documentation/devicetree/bindings/pps/pps-gpio.txt Normal file
View File

@ -0,0 +1,20 @@
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;
};

133
drivers/pps/clients/pps-gpio.c
View File

@ -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;
/* GPIO setup */
ret = pps_gpio_setup(pdev);
if (ret)
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);
return -EINVAL;
}
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 == NULL)
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 = 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 */
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;
}
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),
},
};