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path: root/drivers/w1/masters/w1-gpio.c
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Diffstat (limited to 'drivers/w1/masters/w1-gpio.c')
-rw-r--r--drivers/w1/masters/w1-gpio.c66
1 files changed, 64 insertions, 2 deletions
diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index df600d14974..6012c4ea320 100644
--- a/drivers/w1/masters/w1-gpio.c
+++ b/drivers/w1/masters/w1-gpio.c
@@ -14,6 +14,8 @@
#include <linux/slab.h>
#include <linux/w1-gpio.h>
#include <linux/gpio.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
#include "../w1.h"
#include "../w1_int.h"
@@ -42,12 +44,55 @@ static u8 w1_gpio_read_bit(void *data)
return gpio_get_value(pdata->pin) ? 1 : 0;
}
+#ifdef CONFIG_OF
+static struct of_device_id w1_gpio_dt_ids[] = {
+ { .compatible = "w1-gpio" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
+
+static int w1_gpio_probe_dt(struct platform_device *pdev)
+{
+ struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
+ struct device_node *np = pdev->dev.of_node;
+ const struct of_device_id *of_id =
+ of_match_device(w1_gpio_dt_ids, &pdev->dev);
+
+ if (!of_id)
+ return 0;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ if (of_get_property(np, "linux,open-drain", NULL))
+ pdata->is_open_drain = 1;
+
+ pdata->pin = of_get_gpio(np, 0);
+ pdata->ext_pullup_enable_pin = of_get_gpio(np, 1);
+ pdev->dev.platform_data = pdata;
+
+ return 0;
+}
+#else
+static int w1_gpio_probe_dt(struct platform_device *pdev)
+{
+ return 0;
+}
+#endif
+
static int __init w1_gpio_probe(struct platform_device *pdev)
{
struct w1_bus_master *master;
- struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
+ struct w1_gpio_platform_data *pdata;
int err;
+ err = w1_gpio_probe_dt(pdev);
+ if (err < 0)
+ return err;
+
+ pdata = pdev->dev.platform_data;
+
if (!pdata)
return -ENXIO;
@@ -59,6 +104,13 @@ static int __init w1_gpio_probe(struct platform_device *pdev)
if (err)
goto free_master;
+ if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
+ err = gpio_request_one(pdata->ext_pullup_enable_pin,
+ GPIOF_INIT_LOW, "w1 pullup");
+ if (err < 0)
+ goto free_gpio;
+ }
+
master->data = pdata;
master->read_bit = w1_gpio_read_bit;
@@ -72,15 +124,21 @@ static int __init w1_gpio_probe(struct platform_device *pdev)
err = w1_add_master_device(master);
if (err)
- goto free_gpio;
+ goto free_gpio_ext_pu;
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
+ if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+ gpio_set_value(pdata->ext_pullup_enable_pin, 1);
+
platform_set_drvdata(pdev, master);
return 0;
+ free_gpio_ext_pu:
+ if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+ gpio_free(pdata->ext_pullup_enable_pin);
free_gpio:
gpio_free(pdata->pin);
free_master:
@@ -97,6 +155,9 @@ static int __exit w1_gpio_remove(struct platform_device *pdev)
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
+ if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+ gpio_set_value(pdata->ext_pullup_enable_pin, 0);
+
w1_remove_master_device(master);
gpio_free(pdata->pin);
kfree(master);
@@ -135,6 +196,7 @@ static struct platform_driver w1_gpio_driver = {
.driver = {
.name = "w1-gpio",
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(w1_gpio_dt_ids),
},
.remove = __exit_p(w1_gpio_remove),
.suspend = w1_gpio_suspend,