ENGR00126326-2 - MAX17135: Add support for temperature sensor monitoring

- MAX17135 re-architected:
	- Core functionality, including I2C access to the chip, moved into
	drivers/mfd/max17135-core.c
	- MAX17135 regulators registered via init() callback in plat-specific
	code.
	- All access to registers funnelled through max17135_reg_read/write() apis.
	- max17135.h moved from regulator/ folder into mfd/ folder.

- Support for reading internal and external temperature via sysfs interface,
consistent with lm-sensors hwmon interface.

Signed-off-by: Danny Nold <dannynold@freescale.com>

3 files changed, 183 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index b5d3a46085ea..ef2838639b78 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -652,6 +652,15 @@ config SENSORS_MAX1619
 	  This driver can also be built as a module.  If so, the module
 	  will be called max1619.
 
+config SENSORS_MAX17135
+	tristate "Maxim MAX17135"
+	depends on I2C
+	help
+	  If you say yes here you get support for MAX17135 PMIC sensor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called max17135_sensor.
+
 config SENSORS_MAX6650
 	tristate "Maxim MAX6650 sensor chip"
 	depends on I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 1f5dccc660b7..ed5464b37e57 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -78,6 +78,7 @@ obj-$(CONFIG_SENSORS_LTC4215)	+= ltc4215.o
 obj-$(CONFIG_SENSORS_LTC4245)	+= ltc4245.o
 obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o
 obj-$(CONFIG_SENSORS_MAX1619)	+= max1619.o
+obj-$(CONFIG_SENSORS_MAX17135)	+= max17135-hwmon.o
 obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o
 obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
diff --git a/drivers/hwmon/max17135-hwmon.c b/drivers/hwmon/max17135-hwmon.c
new file mode 100644
index 000000000000..8aa9aadbd44a
--- /dev/null
+++ b/drivers/hwmon/max17135-hwmon.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2010 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+/*
+ * max17135.c
+ *
+ * Based on the MAX1619 driver.
+ * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
+ *                         Jean Delvare <khali@linux-fr.org>
+ *
+ * The MAX17135 is a sensor chip made by Maxim.
+ * It reports up to two temperatures (its own plus up to
+ * one external one).
+ */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/max17135.h>
+
+/*
+ * Conversions
+ */
+static int temp_from_reg(int val)
+{
+	return val >> 8;
+}
+
+/*
+ * Functions declaration
+ */
+static int max17135_sensor_probe(struct platform_device *pdev);
+static int max17135_sensor_remove(struct platform_device *pdev);
+
+/*
+ * Driver data (common to all clients)
+ */
+static struct platform_driver max17135_sensor_driver = {
+	.probe = max17135_sensor_probe,
+	.remove = max17135_sensor_remove,
+	.driver = {
+		.name = "max17135_sensor",
+	},
+};
+
+
+/*
+ * Client data (each client gets its own)
+ */
+struct max17135_data {
+	struct device *hwmon_dev;
+};
+
+/*
+ * Sysfs stuff
+ */
+static ssize_t show_temp_input1(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	unsigned int reg_val;
+	max17135_reg_read(REG_MAX17135_INT_TEMP, &reg_val);
+	return snprintf(buf, PAGE_SIZE, "%d\n", temp_from_reg(reg_val));
+}
+
+static ssize_t show_temp_input2(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	unsigned int reg_val;
+	max17135_reg_read(REG_MAX17135_EXT_TEMP, &reg_val);
+	return snprintf(buf, PAGE_SIZE, "%d\n", temp_from_reg(reg_val));
+}
+
+show_temp(temp_input1);
+show_temp(temp_input2);
+
+static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
+static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
+
+static struct attribute *max17135_attributes[] = {
+	&dev_attr_temp1_input.attr,
+	&dev_attr_temp2_input.attr,
+	NULL
+};
+
+static const struct attribute_group max17135_group = {
+	.attrs = max17135_attributes,
+};
+
+/*
+ * Real code
+ */
+static int max17135_sensor_probe(struct platform_device *pdev)
+{
+	struct max17135_data *data;
+	int err;
+
+	data = kzalloc(sizeof(struct max17135_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&pdev->dev.kobj, &max17135_group);
+	if (err)
+		goto exit_free;
+
+	data->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove_files;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	return 0;
+
+exit_remove_files:
+	sysfs_remove_group(&pdev->dev.kobj, &max17135_group);
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int max17135_sensor_remove(struct platform_device *pdev)
+{
+	struct max17135_data *data = platform_get_drvdata(pdev);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&pdev->dev.kobj, &max17135_group);
+
+	kfree(data);
+	return 0;
+}
+
+static int __init sensors_max17135_init(void)
+{
+	return platform_driver_register(&max17135_sensor_driver);
+}
+module_init(sensors_max17135_init);
+
+static void __exit sensors_max17135_exit(void)
+{
+	platform_driver_unregister(&max17135_sensor_driver);
+}
+module_exit(sensors_max17135_exit);
+
+MODULE_DESCRIPTION("MAX17135 sensor driver");
+MODULE_LICENSE("GPL");
+