[PATCH RFC 1/1] MISC: Broadcom BCM4751 GPS driver

[Matti J. Aaltonen]

Driver for Broadcom BCM4751 GPS chip.

Signed-off-by: Matti J. Aaltonen <matti.j.aaltonen@xxxxxxxxx>
---
 drivers/misc/Kconfig            |   11 +
 drivers/misc/Makefile           |    1 +
 drivers/misc/bcm4751-gps.c      |  490 +++++++++++++++++++++++++++++++++++++++
 include/linux/i2c/bcm4751-gps.h |   59 +++++
 4 files changed, 561 insertions(+), 0 deletions(-)
 create mode 100644 drivers/misc/bcm4751-gps.c
 create mode 100644 include/linux/i2c/bcm4751-gps.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 0b591b6..1680673 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -390,6 +390,17 @@ config BMP085
 	  To compile this driver as a module, choose M here: the
 	  module will be called bmp085.
 
+config BCM4751_GPS
+	tristate "BCM4751 GPS driver"
+	depends on I2C
+	default n
+	---help---
+	  If you say yes here you get support for the Broadcom BCM4751 GPS
+	  chip driver.
+
+	  The driver supports only GPS in BCM4751 chip. When built as a driver
+	  driver name is: bcm4751-gps. If unsure, say N here.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 255a80d..cfda6fb 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_AD525X_DPOT_SPI)	+= ad525x_dpot-spi.o
 obj-$(CONFIG_ATMEL_PWM)		+= atmel_pwm.o
 obj-$(CONFIG_ATMEL_SSC)		+= atmel-ssc.o
 obj-$(CONFIG_ATMEL_TCLIB)	+= atmel_tclib.o
+obj-$(CONFIG_BCM4751_GPS)	+= bcm4751-gps.o
 obj-$(CONFIG_BMP085)		+= bmp085.o
 obj-$(CONFIG_ICS932S401)	+= ics932s401.o
 obj-$(CONFIG_LKDTM)		+= lkdtm.o
diff --git a/drivers/misc/bcm4751-gps.c b/drivers/misc/bcm4751-gps.c
new file mode 100644
index 0000000..03a3752
--- /dev/null
+++ b/drivers/misc/bcm4751-gps.c
@@ -0,0 +1,490 @@
+/*
+ * bcm4751-gps.c - Hardware interface for Broadcom BCM4751 GPS chip.
+ *
+ * Copyright (C)	2010 Nokia Corporation
+ * Contact		Matti Aaltonen, matti.j.aaltonen@xxxxxxxxx
+ *
+ * Written by Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
+ * Modified by Yuri Zaporozhets <ext-yuri.zaporozhets@xxxxxxxxx>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#define DEBUG
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/i2c-dev.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <linux/i2c/bcm4751-gps.h>
+
+static struct bcm4751_gps_data		*bcm4751_gps_device;
+
+static const char reg_vbat[] = "Vbat";
+static const char reg_vddio[] = "Vddio";
+
+/*
+ * Part of initialization is done in the board support file.
+ */
+
+static inline void bcm4751_gps_enable(struct bcm4751_gps_data *self)
+{
+	mutex_lock(&self->mutex);
+	if (!self->enable) {
+		regulator_bulk_enable(ARRAY_SIZE(self->regs), self->regs);
+		if (self->pdata->enable)
+			self->pdata->enable(self->client);
+		self->enable = 1;
+	}
+	mutex_unlock(&self->mutex);
+}
+
+static inline void bcm4751_gps_disable(struct bcm4751_gps_data *self)
+{
+	mutex_lock(&self->mutex);
+	if (self->enable) {
+		if (self->pdata->disable)
+			self->pdata->disable(self->client);
+		self->enable = 0;
+		regulator_bulk_disable(ARRAY_SIZE(self->regs), self->regs);
+	}
+	mutex_unlock(&self->mutex);
+}
+
+static inline void bcm4751_gps_wakeup_value(struct bcm4751_gps_data *self,
+		int value)
+{
+	mutex_lock(&self->mutex);
+	if (self->pdata->wakeup_ctrl)
+		self->pdata->wakeup_ctrl(self->client, value);
+	self->wakeup = value;
+	mutex_unlock(&self->mutex);
+}
+
+
+/*
+ * miscdevice interface
+ */
+
+static int bcm4751_gps_open(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+static int bcm4751_gps_release(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+static ssize_t bcm4751_gps_read(struct file *file, char __user *buf,
+		size_t count, loff_t *offset)
+{
+	struct i2c_client *client = bcm4751_gps_device->client;
+	int num_read;
+	uint8_t	tmp[BCM4751_MAX_BINPKT_RX_LEN];
+
+	/* Adjust for binary packet size */
+	if (count > BCM4751_MAX_BINPKT_RX_LEN)
+		count = BCM4751_MAX_BINPKT_RX_LEN;
+
+	dev_dbg(&client->dev, "reading %d bytes\n", count);
+
+	num_read = i2c_master_recv(client, tmp, count);
+
+	if (num_read < 0) {
+		dev_err(&client->dev, "got %d bytes instead of %d\n",
+			num_read, count);
+		return num_read;
+	} else {
+		dev_dbg(&client->dev, "reading %d bytes returns %d",
+			count, num_read);
+	}
+
+	return copy_to_user(buf, tmp, num_read) ? -EFAULT : num_read;
+}
+
+static ssize_t bcm4751_gps_write(struct file *file, const char __user *buf,
+		size_t count, loff_t *offset)
+{
+	struct i2c_client *client = bcm4751_gps_device->client;
+	uint8_t tmp[BCM4751_MAX_BINPKT_TX_LEN];
+	int num_sent;
+
+	if (count > BCM4751_MAX_BINPKT_TX_LEN)
+		count = BCM4751_MAX_BINPKT_TX_LEN;
+
+	dev_dbg(&client->dev, "writing %d bytes\n", count);
+
+	if (copy_from_user(tmp, buf, count))
+		return -EFAULT;
+
+	num_sent = i2c_master_send(client, tmp, count);
+
+	dev_dbg(&client->dev, "writing %d bytes returns %d",
+		count, num_sent);
+
+	return num_sent;
+}
+
+static int bcm4751_gps_ioctl(struct inode *inode, struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	struct i2c_client *client = bcm4751_gps_device->client;
+
+	dev_dbg(&client->dev, "ioctl: cmd = 0x%02x, arg=0x%02lx\n", cmd, arg);
+
+	switch (cmd) {
+	case I2C_SLAVE:
+	case I2C_SLAVE_FORCE:
+		if ((arg > 0x3ff) ||
+				(((client->flags & I2C_M_TEN) == 0) &&
+				 arg > 0x7f))
+			return -EINVAL;
+		client->addr = arg;
+		dev_dbg(&client->dev, "ioctl: client->addr = %x", client->addr);
+		return 0;
+	case I2C_TENBIT:
+		if (arg)
+			client->flags |= I2C_M_TEN;
+		else
+			client->flags &= ~I2C_M_TEN;
+		return 0;
+	default:
+		return -ENOTTY;
+	}
+	return 0;
+}
+
+static const struct file_operations bcm4751_gps_fileops = {
+	.owner = THIS_MODULE,
+	.llseek		= no_llseek,
+	.read		= bcm4751_gps_read,
+	.write		= bcm4751_gps_write,
+	.unlocked_ioctl	= bcm4751_gps_ioctl,
+	.open		= bcm4751_gps_open,
+	.release	= bcm4751_gps_release,
+};
+
+static struct miscdevice bcm4751_gps_miscdevice = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "bcm4751-gps",
+	.fops = &bcm4751_gps_fileops
+};
+
+
+/*
+ * sysfs interface
+ */
+
+static ssize_t bcm4751_gps_show_hostreq(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct bcm4751_gps_data *self = dev_get_drvdata(dev);
+	int value = -1;
+
+	if (self->pdata->show_irq)
+		value = self->pdata->show_irq(self->client);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", value);
+}
+
+static ssize_t bcm4751_gps_show_enable(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct bcm4751_gps_data *self = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", self->enable);
+}
+
+static ssize_t bcm4751_gps_set_enable(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct bcm4751_gps_data *self = dev_get_drvdata(dev);
+	int value;
+
+	sscanf(buf, "%d", &value);
+	dev_dbg(dev, "enable: %d", value);
+
+	switch (value) {
+	case 0:
+		bcm4751_gps_disable(self);
+		break;
+
+	case 1:
+		bcm4751_gps_enable(self);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+	return len;
+}
+
+static ssize_t bcm4751_gps_show_wakeup(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct bcm4751_gps_data *self = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", self->wakeup);
+}
+
+static ssize_t bcm4751_gps_set_wakeup(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	unsigned long val;
+	int ret;
+	struct bcm4751_gps_data *self = dev_get_drvdata(dev);
+
+	ret = strict_strtoul(buf, 0, &val);
+	if (ret && val > 1)
+		return -EINVAL;
+	else {
+		bcm4751_gps_wakeup_value(self, val);
+		dev_dbg(dev, "new wakeup value = %d", self->wakeup);
+	}
+
+	return len;
+}
+
+static struct device_attribute bcm4751_gps_attrs[] = {
+	__ATTR(enable, S_IRUGO|S_IWUSR,
+			bcm4751_gps_show_enable, bcm4751_gps_set_enable),
+	__ATTR(hostreq, S_IRUGO|S_IWUSR,
+			bcm4751_gps_show_hostreq, NULL),
+	__ATTR(wakeup, S_IRUGO|S_IWUSR,
+			bcm4751_gps_show_wakeup, bcm4751_gps_set_wakeup),
+};
+
+static int bcm4751_gps_register_sysfs(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(bcm4751_gps_attrs); i++) {
+		ret = device_create_file(dev, &bcm4751_gps_attrs[i]);
+		if (ret)
+			goto fail;
+	}
+	return 0;
+fail:
+	while (i--)
+		device_remove_file(dev, &bcm4751_gps_attrs[i]);
+
+	return ret;
+}
+
+static void bcm4751_gps_unregister_sysfs(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	int i;
+
+	for (i = ARRAY_SIZE(bcm4751_gps_attrs) - 1; i >= 0; i--)
+		device_remove_file(dev, &bcm4751_gps_attrs[i]);
+}
+
+/* IRQ thread */
+static irqreturn_t bcm4751_gps_irq_thread(int irq, void *dev_id)
+{
+	struct bcm4751_gps_data *data = dev_id;
+
+	dev_dbg(&data->client->dev, "irq, HOST_REQ=%d",
+			data->pdata->show_irq(data->client));
+
+	/* Update sysfs GPIO line here */
+	sysfs_notify(&data->client->dev.kobj, NULL, "hostreq");
+	return IRQ_HANDLED;
+}
+
+static int bcm4751_gps_probe(struct i2c_client *client,
+		const struct i2c_device_id *device_id)
+{
+	struct bcm4751_gps_data			*data;
+	struct bcm4751_gps_platform_data	*pdata;
+	int					err;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	bcm4751_gps_device = data;
+
+	pdata = client->dev.platform_data;
+	if (!pdata) {
+		dev_err(&client->dev, "no platform data\n");
+		err = -ENODEV;
+		goto clean_data;
+	}
+
+	i2c_set_clientdata(client, data);
+	data->client = client;
+	data->pdata  = pdata;
+
+	data->gpio_irq    = pdata->gps_gpio_irq;
+	data->gpio_enable = pdata->gps_gpio_enable;
+	data->gpio_wakeup = pdata->gps_gpio_wakeup;
+
+	data->regs[0].supply = reg_vbat;
+	data->regs[1].supply = reg_vddio;
+	err = regulator_bulk_get(&client->dev,
+				ARRAY_SIZE(data->regs), data->regs);
+	if (err < 0) {
+		dev_err(&client->dev, "Can't get regulators\n");
+		goto clean_data;
+	}
+
+	if (pdata->setup) {
+		err = pdata->setup(client);
+		if (err)
+			goto clean_reg;
+	}
+
+	mutex_init(&data->mutex);
+	err = request_threaded_irq(client->irq, NULL,
+				bcm4751_gps_irq_thread,
+				IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+				"bcm4751-gps", data);
+	if (err) {
+		dev_err(&client->dev, "could not get GPS_IRQ = %d\n",
+				client->irq);
+		goto clean_setup;
+	}
+
+	err = bcm4751_gps_register_sysfs(client);
+	if (err) {
+		dev_err(&client->dev,
+				"sysfs registration failed, error %d\n", err);
+		goto clean_irq;
+	}
+
+	bcm4751_gps_miscdevice.parent = &client->dev;
+	err = misc_register(&bcm4751_gps_miscdevice);
+	if (err) {
+		dev_err(&client->dev, "Miscdevice register failed\n");
+		goto clean_sysfs;
+	}
+
+	return 0;
+
+clean_sysfs:
+	bcm4751_gps_unregister_sysfs(client);
+
+clean_irq:
+	free_irq(client->irq, data);
+
+clean_setup:
+	if (pdata->cleanup)
+		pdata->cleanup(client);
+clean_reg:
+	regulator_bulk_free(ARRAY_SIZE(data->regs), data->regs);
+clean_data:
+	bcm4751_gps_device = NULL;
+	kfree(data);
+
+	return err;
+}
+
+static int bcm4751_gps_remove(struct i2c_client *client)
+{
+	struct bcm4751_gps_data *data = i2c_get_clientdata(client);
+
+	bcm4751_gps_disable(data);
+
+	free_irq(client->irq, data);
+	misc_deregister(&bcm4751_gps_miscdevice);
+	bcm4751_gps_unregister_sysfs(client);
+	if (data->pdata->cleanup)
+		data->pdata->cleanup(client);
+	regulator_bulk_free(ARRAY_SIZE(data->regs), data->regs);
+	kfree(data);
+	bcm4751_gps_device = NULL;
+
+	return 0;
+}
+
+static void bcm4751_gps_shutdown(struct i2c_client *client)
+{
+	dev_dbg(&client->dev, "BCM4751 shutdown\n");
+	bcm4751_gps_disable(i2c_get_clientdata(client));
+}
+
+#ifdef CONFIG_PM
+static int bcm4751_gps_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	struct bcm4751_gps_data *data = i2c_get_clientdata(client);
+	data->pdata->wakeup_ctrl(data->client, 0);
+	dev_dbg(&client->dev, "BCM4751 suspends\n");
+	return 0;
+}
+
+static int bcm4751_gps_resume(struct i2c_client *client)
+{
+	struct bcm4751_gps_data *data = i2c_get_clientdata(client);
+	data->pdata->wakeup_ctrl(data->client, 1);
+	dev_dbg(&client->dev, "BCM4751 resumes\n");
+	return 0;
+}
+#else
+#define bcm4751_gps_suspend NULL
+#define bcm4751_gps_resume NULL
+#endif
+
+static const struct i2c_device_id bcm4751_gps_id[] = {
+	{ "bcm4751-gps", 0 },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(i2c, bcm4751_gps_id);
+
+static struct i2c_driver bcm4751_gps_i2c_driver = {
+	.driver = {
+		.name	 = "bcm4751-gps",
+	},
+
+	.id_table	= bcm4751_gps_id,
+	.probe		= bcm4751_gps_probe,
+	.remove		= __devexit_p(bcm4751_gps_remove),
+	.shutdown	= bcm4751_gps_shutdown,
+	.suspend	= bcm4751_gps_suspend,
+	.resume		= bcm4751_gps_resume,
+};
+
+static int __init bcm4751_gps_init(void)
+{
+	pr_info("Loading BCM4751 GPS driver\n");
+
+	return i2c_add_driver(&bcm4751_gps_i2c_driver);
+}
+module_init(bcm4751_gps_init);
+
+static void __exit bcm4751_gps_exit(void)
+{
+	i2c_del_driver(&bcm4751_gps_i2c_driver);
+}
+module_exit(bcm4751_gps_exit);
+
+MODULE_AUTHOR("Andrei Emeltchenko, Yuri Zaporozhets");
+MODULE_DESCRIPTION("BCM4751 GPS driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/i2c/bcm4751-gps.h b/include/linux/i2c/bcm4751-gps.h
new file mode 100644
index 0000000..69834b9
--- /dev/null
+++ b/include/linux/i2c/bcm4751-gps.h
@@ -0,0 +1,59 @@
+/*
+ * @file include/linux/i2c/bcm4751-gps.h
+ *
+ *
+ * Copyright (C)	2010 Nokia Corporation
+ * Contact		Matti Aaltonen, matti.j.aaltonen@xxxxxxxxx
+ *
+ * Written by Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx>
+ * Modified by Yuri Zaporozhets <ext-yuri.zaporozhets@xxxxxxxxx>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef _LINUX_I2C_BCM4751_GPS_H
+#define _LINUX_I2C_BCM4751_GPS_H
+
+/* Max packet sizes for RX and TX */
+#define BCM4751_MAX_BINPKT_RX_LEN	64
+#define BCM4751_MAX_BINPKT_TX_LEN	64
+
+/* Plaform data, used by the board support file */
+struct bcm4751_gps_platform_data {
+	int gps_gpio_irq;
+	int gps_gpio_enable;
+	int gps_gpio_wakeup;
+	int	(*setup)(struct i2c_client *client);
+	void	(*cleanup)(struct i2c_client *client);
+	void	(*enable)(struct i2c_client *client);
+	void	(*disable)(struct i2c_client *client);
+	void	(*wakeup_ctrl)(struct i2c_client *client, int value);
+	int	(*show_irq)(struct i2c_client *client);
+};
+
+/* Used internally by the driver */
+struct bcm4751_gps_data {
+	struct i2c_client		*client;
+	struct bcm4751_gps_platform_data *pdata;
+	struct mutex                    mutex; /* Serialize things */
+	struct regulator_bulk_data	regs[2];
+	unsigned int			gpio_irq;
+	unsigned int			gpio_enable;
+	unsigned int			gpio_wakeup;
+	int				enable;
+	int				wakeup;
+};
+
+#endif
-- 
1.6.1.3

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