misc: Initial NCT1008 driver

Initial version of the NCT1008 driver to turn off the sensor when the
device is suspended.  This improves standby current drain.

Change-Id: Ia64613c33c0052434d5e304c434605611e5ef789
Signed-off-by: Greg Meiste <w30289@motorola.com>

3 files changed, 148 insertions, 0 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index b74331260744..aad1247743f7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -321,6 +321,14 @@ config HMC6352
 	  This driver provides support for the Honeywell HMC6352 compass,
 	  providing configuration and heading data via sysfs.
 
+config SENSORS_NCT1008
+	tristate "ON Semiconductor Temperature Sensor"
+	default n
+	depends on I2C
+	help
+	 Say yes here if you wish to include the ON Semiconductor
+	 NCT1008 Temperature sensor.
+
 config EP93XX_PWM
 	tristate "EP93xx PWM support"
 	depends on ARCH_EP93XX
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 42eab95cde2a..51f2787d8d15 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -35,3 +35,4 @@ obj-y				+= eeprom/
 obj-y				+= cb710/
 obj-$(CONFIG_VMWARE_BALLOON)	+= vmw_balloon.o
 obj-$(CONFIG_ARM_CHARLCD)	+= arm-charlcd.o
+obj-$(CONFIG_SENSORS_NCT1008)	+= nct1008.o
diff --git a/drivers/misc/nct1008.c b/drivers/misc/nct1008.c
new file mode 100755
index 000000000000..a29e984bc4c6
--- /dev/null
+++ b/drivers/misc/nct1008.c
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2010 Motorola, Inc.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307, USA
+ */
+
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/nct1008.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#define NCT_BIT_CONFIG_RUN_STOP 6
+
+struct nct1008_data {
+	struct i2c_client *client;
+};
+
+static uint32_t nct1008_debug;
+module_param_named(temp_debug, nct1008_debug, uint, 0664);
+
+static int nct1008_run(struct nct1008_data *nct, u8 run)
+{
+	int err;
+	u8 rd_val;
+	u8 wr_val;
+
+	rd_val = i2c_smbus_read_byte_data(nct->client, NCT_CONFIG_RD);
+	if (rd_val < 0) {
+		pr_err("%s: config register read fail: %d\n", __func__, rd_val);
+		return rd_val;
+	}
+
+	if (nct1008_debug)
+		pr_info("%s: Previous config is 0x%02x\n", __func__, rd_val);
+
+	if (run)
+		wr_val = rd_val & ~(1 << NCT_BIT_CONFIG_RUN_STOP);
+	else
+		wr_val = rd_val | (1 << NCT_BIT_CONFIG_RUN_STOP);
+	err = i2c_smbus_write_byte_data(nct->client, NCT_CONFIG_WR, wr_val);
+	if (err)
+		pr_err("%s: setting RUN/STOP failed: %d\n", __func__, err);
+
+	return err;
+}
+
+static int nct1008_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct nct1008_data *nct;
+
+	nct = kzalloc(sizeof(struct nct1008_data), GFP_KERNEL);
+	if (nct == NULL)
+		return -ENOMEM;
+
+	nct->client = client;
+	i2c_set_clientdata(client, nct);
+
+	return 0;
+}
+
+static int nct1008_remove(struct i2c_client *client)
+{
+	struct nct1008_data *nct = i2c_get_clientdata(client);
+
+	kfree(nct);
+	return 0;
+}
+
+static int nct1008_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	struct nct1008_data *nct = i2c_get_clientdata(client);
+
+	if (nct1008_debug)
+		pr_info("%s: Suspending\n", __func__);
+
+	return nct1008_run(nct, 0);
+}
+
+static int nct1008_resume(struct i2c_client *client)
+{
+	struct nct1008_data *nct = i2c_get_clientdata(client);
+
+	if (nct1008_debug)
+		pr_info("%s: Resuming\n", __func__);
+
+	return nct1008_run(nct, 1);
+}
+
+static const struct i2c_device_id nct1008_id[] = {
+	{"nct1008", 0},
+	{}
+};
+
+static struct i2c_driver nct1008_i2c_driver = {
+	.probe = nct1008_probe,
+	.remove = nct1008_remove,
+	.suspend = nct1008_suspend,
+	.resume = nct1008_resume,
+	.id_table = nct1008_id,
+	.driver = {
+		.name = "nct1008",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init nct1008_init(void)
+{
+	return i2c_add_driver(&nct1008_i2c_driver);
+}
+
+static void __exit nct1008_exit(void)
+{
+	i2c_del_driver(&nct1008_i2c_driver);
+}
+
+module_init(nct1008_init);
+module_exit(nct1008_exit);
+
+MODULE_DESCRIPTION("Temperature sensor driver for OnSemi NCT1008");
+MODULE_AUTHOR("Motorola");
+MODULE_LICENSE("GPL");