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, 240 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 9da0e504bbe9..92d59373b0cf 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -482,6 +482,13 @@ config MFD_JANZ_CMODIO
 	  host many different types of MODULbus daughterboards, including
 	  CAN and GPIO controllers.
 
+config MFD_MAX17135
+    tristate "MAX17135 PMIC core"
+	depends on I2C
+    help
+      This is the MAX17135 PMIC support. It includes
+      core support for communication with the MAX17135 chip.
+
 endif # MFD_SUPPORT
 
 menu "Multimedia Capabilities Port drivers"
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index fb503e77dc60..3c4a3b53fafd 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -71,3 +71,4 @@ obj-$(CONFIG_PMIC_ADP5520)	+= adp5520.o
 obj-$(CONFIG_LPC_SCH)		+= lpc_sch.o
 obj-$(CONFIG_MFD_RDC321X)	+= rdc321x-southbridge.o
 obj-$(CONFIG_MFD_JANZ_CMODIO)	+= janz-cmodio.o
+obj-$(CONFIG_MFD_MAX17135)  += max17135-core.o
diff --git a/drivers/mfd/max17135-core.c b/drivers/mfd/max17135-core.c
new file mode 100644
index 000000000000..0be007fbcb40
--- /dev/null
+++ b/drivers/mfd/max17135-core.c
@@ -0,0 +1,232 @@
+/*
+ * 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
+ *
+ */
+
+/*!
+ * @file pmic/core/max17135.c
+ * @brief This file contains MAX17135 specific PMIC code. This implementaion
+ * may differ for each PMIC chip.
+ *
+ * @ingroup PMIC_CORE
+ */
+
+/*
+ * Includes
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/uaccess.h>
+
+#include <linux/platform_device.h>
+#include <linux/regulator/machine.h>
+#include <linux/pmic_status.h>
+#include <linux/mfd/max17135.h>
+#include <asm/mach-types.h>
+
+struct i2c_client *max17135_client;
+
+static const unsigned short normal_i2c[] = {0x48, I2C_CLIENT_END};
+
+int max17135_reg_read(int reg_num, unsigned int *reg_val)
+{
+	int result;
+
+	if (max17135_client == NULL)
+		return PMIC_ERROR;
+
+	if ((reg_num == REG_MAX17135_EXT_TEMP) ||
+		(reg_num == REG_MAX17135_INT_TEMP)) {
+		result = i2c_smbus_read_word_data(max17135_client, reg_num);
+		if (result < 0) {
+			dev_err(&max17135_client->dev,
+				"Unable to read MAX17135 register via I2C\n");
+			return PMIC_ERROR;
+		}
+		/* Swap bytes for dword read */
+		result = (result >> 8) | ((result & 0xFF) << 8);
+	} else {
+		result = i2c_smbus_read_byte_data(max17135_client, reg_num);
+		if (result < 0) {
+			dev_err(&max17135_client->dev,
+				"Unable to read MAX17135 register via I2C\n");
+			return PMIC_ERROR;
+		}
+	}
+
+	*reg_val = result;
+	return PMIC_SUCCESS;
+}
+
+int max17135_reg_write(int reg_num, const unsigned int reg_val)
+{
+	int result;
+
+	if (max17135_client == NULL)
+		return PMIC_ERROR;
+
+	result = i2c_smbus_write_byte_data(max17135_client, reg_num, reg_val);
+	if (result < 0) {
+		dev_err(&max17135_client->dev,
+			"Unable to write MAX17135 register via I2C\n");
+		return PMIC_ERROR;
+	}
+
+	return PMIC_SUCCESS;
+}
+
+static int max17135_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct max17135 *max17135;
+	struct max17135_platform_data *pdata = client->dev.platform_data;
+	int ret = 0;
+
+	if (!pdata || !pdata->init)
+		return -ENODEV;
+
+	/* Create the PMIC data structure */
+	max17135 = kzalloc(sizeof(struct max17135), GFP_KERNEL);
+	if (max17135 == NULL) {
+		kfree(client);
+		return -ENOMEM;
+	}
+
+	/* Initialize the PMIC data structure */
+	i2c_set_clientdata(client, max17135);
+	max17135->dev = &client->dev;
+	max17135->i2c_client = client;
+
+	max17135_client = client;
+
+	if (pdata && pdata->init) {
+		ret = pdata->init(max17135);
+		if (ret != 0)
+			goto err;
+	}
+
+	dev_info(&client->dev, "PMIC MAX17135 for eInk display\n");
+
+	return ret;
+err:
+	kfree(max17135);
+
+	return ret;
+}
+
+
+static int max17135_remove(struct i2c_client *i2c)
+{
+	struct max17135 *max17135 = i2c_get_clientdata(i2c);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(max17135->pdev); i++)
+		platform_device_unregister(max17135->pdev[i]);
+
+	kfree(max17135);
+
+	return 0;
+}
+
+static int max17135_suspend(struct i2c_client *client, pm_message_t state)
+{
+	return 0;
+}
+
+static int max17135_resume(struct i2c_client *client)
+{
+	return 0;
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int max17135_detect(struct i2c_client *client,
+			  struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	u8 chip_rev, chip_id;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	/* detection */
+	if (i2c_smbus_read_byte_data(client,
+		REG_MAX17135_PRODUCT_REV) != 0) {
+		dev_err(&adapter->dev,
+			"Max17135 PMIC not found!\n");
+		return -ENODEV;
+	}
+
+	/* identification */
+	chip_rev = i2c_smbus_read_byte_data(client,
+		 REG_MAX17135_PRODUCT_REV);
+	chip_id = i2c_smbus_read_byte_data(client,
+		  REG_MAX17135_PRODUCT_ID);
+
+	if (chip_rev != 0x00 || chip_id != 0x4D) { /* identification failed */
+		dev_info(&adapter->dev,
+		    "Unsupported chip (man_id=0x%02X, "
+		    "chip_id=0x%02X).\n", chip_rev, chip_id);
+		return -ENODEV;
+	}
+
+	strlcpy(info->type, "max17135_sensor", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static const struct i2c_device_id max17135_id[] = {
+       { "max17135", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, max17135_id);
+
+
+static struct i2c_driver max17135_driver = {
+	.driver = {
+		   .name = "max17135",
+		   .owner = THIS_MODULE,
+	},
+	.probe = max17135_probe,
+	.remove = max17135_remove,
+	.suspend = max17135_suspend,
+	.resume = max17135_resume,
+	.id_table = max17135_id,
+	.detect = max17135_detect,
+	.address_list = &normal_i2c,
+};
+
+static int __init max17135_init(void)
+{
+	return i2c_add_driver(&max17135_driver);
+}
+
+static void __exit max17135_exit(void)
+{
+	i2c_del_driver(&max17135_driver);
+}
+
+/*
+ * Module entry points
+ */
+subsys_initcall_sync(max17135_init);
+module_exit(max17135_exit);