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: 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>

1 files changed, 73 insertions, 54 deletions

diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c
index 5bd3bf093b54..eae0eda9ff39 100644
--- a/drivers/pps/clients/pps-gpio.c
+++ b/drivers/pps/clients/pps-gpio.c
@@ -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),
         },
 };