Initial import

1 files changed, 243 insertions, 0 deletions

diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
new file mode 100644
index 000000000..8f7848c62
--- /dev/null
+++ b/drivers/w1/masters/w1-gpio.c
@@ -0,0 +1,243 @@
+/*
+ * w1-gpio - GPIO w1 bus master driver
+ *
+ * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/w1-gpio.h>
+#include <linux/gpio.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+
+#include "../w1.h"
+#include "../w1_int.h"
+
+static u8 w1_gpio_set_pullup(void *data, int delay)
+{
+	struct w1_gpio_platform_data *pdata = data;
+
+	if (delay) {
+		pdata->pullup_duration = delay;
+	} else {
+		if (pdata->pullup_duration) {
+			gpio_direction_output(pdata->pin, 1);
+
+			msleep(pdata->pullup_duration);
+
+			gpio_direction_input(pdata->pin);
+		}
+		pdata->pullup_duration = 0;
+	}
+
+	return 0;
+}
+
+static void w1_gpio_write_bit_dir(void *data, u8 bit)
+{
+	struct w1_gpio_platform_data *pdata = data;
+
+	if (bit)
+		gpio_direction_input(pdata->pin);
+	else
+		gpio_direction_output(pdata->pin, 0);
+}
+
+static void w1_gpio_write_bit_val(void *data, u8 bit)
+{
+	struct w1_gpio_platform_data *pdata = data;
+
+	gpio_set_value(pdata->pin, bit);
+}
+
+static u8 w1_gpio_read_bit(void *data)
+{
+	struct w1_gpio_platform_data *pdata = data;
+
+	return gpio_get_value(pdata->pin) ? 1 : 0;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id w1_gpio_dt_ids[] = {
+	{ .compatible = "w1-gpio" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
+#endif
+
+static int w1_gpio_probe_dt(struct platform_device *pdev)
+{
+	struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct device_node *np = pdev->dev.of_node;
+	int gpio;
+
+	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;
+
+	gpio = of_get_gpio(np, 0);
+	if (gpio < 0) {
+		if (gpio != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+					"Failed to parse gpio property for data pin (%d)\n",
+					gpio);
+
+		return gpio;
+	}
+	pdata->pin = gpio;
+
+	gpio = of_get_gpio(np, 1);
+	if (gpio == -EPROBE_DEFER)
+		return gpio;
+	/* ignore other errors as the pullup gpio is optional */
+	pdata->ext_pullup_enable_pin = gpio;
+
+	pdev->dev.platform_data = pdata;
+
+	return 0;
+}
+
+static int w1_gpio_probe(struct platform_device *pdev)
+{
+	struct w1_bus_master *master;
+	struct w1_gpio_platform_data *pdata;
+	int err;
+
+	if (of_have_populated_dt()) {
+		err = w1_gpio_probe_dt(pdev);
+		if (err < 0)
+			return err;
+	}
+
+	pdata = dev_get_platdata(&pdev->dev);
+
+	if (!pdata) {
+		dev_err(&pdev->dev, "No configuration data\n");
+		return -ENXIO;
+	}
+
+	master = devm_kzalloc(&pdev->dev, sizeof(struct w1_bus_master),
+			GFP_KERNEL);
+	if (!master) {
+		dev_err(&pdev->dev, "Out of memory\n");
+		return -ENOMEM;
+	}
+
+	err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
+	if (err) {
+		dev_err(&pdev->dev, "gpio_request (pin) failed\n");
+		return err;
+	}
+
+	if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
+		err = devm_gpio_request_one(&pdev->dev,
+				pdata->ext_pullup_enable_pin, GPIOF_INIT_LOW,
+				"w1 pullup");
+		if (err < 0) {
+			dev_err(&pdev->dev, "gpio_request_one "
+					"(ext_pullup_enable_pin) failed\n");
+			return err;
+		}
+	}
+
+	master->data = pdata;
+	master->read_bit = w1_gpio_read_bit;
+
+	if (pdata->is_open_drain) {
+		gpio_direction_output(pdata->pin, 1);
+		master->write_bit = w1_gpio_write_bit_val;
+	} else {
+		gpio_direction_input(pdata->pin);
+		master->write_bit = w1_gpio_write_bit_dir;
+		master->set_pullup = w1_gpio_set_pullup;
+	}
+
+	err = w1_add_master_device(master);
+	if (err) {
+		dev_err(&pdev->dev, "w1_add_master device failed\n");
+		return err;
+	}
+
+	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;
+}
+
+static int w1_gpio_remove(struct platform_device *pdev)
+{
+	struct w1_bus_master *master = platform_get_drvdata(pdev);
+	struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+	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);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int w1_gpio_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+	if (pdata->enable_external_pullup)
+		pdata->enable_external_pullup(0);
+
+	return 0;
+}
+
+static int w1_gpio_resume(struct platform_device *pdev)
+{
+	struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+	if (pdata->enable_external_pullup)
+		pdata->enable_external_pullup(1);
+
+	return 0;
+}
+
+#else
+#define w1_gpio_suspend	NULL
+#define w1_gpio_resume	NULL
+#endif
+
+static struct platform_driver w1_gpio_driver = {
+	.driver = {
+		.name	= "w1-gpio",
+		.of_match_table = of_match_ptr(w1_gpio_dt_ids),
+	},
+	.probe = w1_gpio_probe,
+	.remove	= w1_gpio_remove,
+	.suspend = w1_gpio_suspend,
+	.resume = w1_gpio_resume,
+};
+
+module_platform_driver(w1_gpio_driver);
+
+MODULE_DESCRIPTION("GPIO w1 bus master driver");
+MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
+MODULE_LICENSE("GPL");