hwmon: (pmbus) Add support for TI UCD9200 series of PWM System Controllers

This patch adds hardware monitoring support for TI UCD9220, UCD9222, UCD9224,
UCD9240, UCD9244, UCD9246, and UCD9248 Digital PWM System Controllers.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Reviewed-by: Tom Grennan <tom.grennan@ericsson.com>

3 files changed, 221 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index dff080d..07c4a86 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -857,6 +857,16 @@ config SENSORS_MAX8688
 	  This driver can also be built as a module. If so, the module will
 	  be called max8688.
 
+config SENSORS_UCD9200
+	tristate "TI UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, UCD9248"
+	default n
+	help
+	  If you say yes here you get hardware monitoring support for TI
+	  UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, and UCD9248.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called ucd9200.
+
 endif # PMBUS
 
 config SENSORS_SHT15
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 465f1c8..1afe029 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -123,6 +123,7 @@ obj-$(CONFIG_SENSORS_PMBUS)	+= pmbus.o
 obj-$(CONFIG_SENSORS_MAX16064)	+= max16064.o
 obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
+obj-$(CONFIG_SENSORS_UCD9200)	+= ucd9200.o
 
 ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG
 
diff --git a/drivers/hwmon/ucd9200.c b/drivers/hwmon/ucd9200.c
new file mode 100644
index 0000000..ffcc1cf
--- /dev/null
+++ b/drivers/hwmon/ucd9200.c
@@ -0,0 +1,210 @@
+/*
+ * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers
+ *
+ * Copyright (C) 2011 Ericsson AB.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/i2c/pmbus.h>
+#include "pmbus.h"
+
+#define UCD9200_PHASE_INFO	0xd2
+#define UCD9200_DEVICE_ID	0xfd
+
+enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,
+	     ucd9248 };
+
+static const struct i2c_device_id ucd9200_id[] = {
+	{"ucd9200", ucd9200},
+	{"ucd9220", ucd9220},
+	{"ucd9222", ucd9222},
+	{"ucd9224", ucd9224},
+	{"ucd9240", ucd9240},
+	{"ucd9244", ucd9244},
+	{"ucd9246", ucd9246},
+	{"ucd9248", ucd9248},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ucd9200_id);
+
+static int ucd9200_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
+	struct pmbus_driver_info *info;
+	const struct i2c_device_id *mid;
+	int i, j, ret;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_BLOCK_DATA))
+		return -ENODEV;
+
+	ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,
+					block_buffer);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to read device ID\n");
+		return ret;
+	}
+	block_buffer[ret] = '\0';
+	dev_info(&client->dev, "Device ID %s\n", block_buffer);
+
+	mid = NULL;
+	for (i = 0; i < ARRAY_SIZE(ucd9200_id); i++) {
+		mid = &ucd9200_id[i];
+		if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
+			break;
+	}
+	if (!mid || !strlen(mid->name)) {
+		dev_err(&client->dev, "Unsupported device\n");
+		return -ENODEV;
+	}
+	if (id->driver_data != ucd9200 && id->driver_data != mid->driver_data)
+		dev_notice(&client->dev,
+			   "Device mismatch: Configured %s, detected %s\n",
+			   id->name, mid->name);
+
+	info = kzalloc(sizeof(struct pmbus_driver_info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,
+					block_buffer);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to read phase information\n");
+		goto out;
+	}
+
+	/*
+	 * Calculate number of configured pages (rails) from PHASE_INFO
+	 * register.
+	 * Rails have to be sequential, so we can abort after finding
+	 * the first unconfigured rail.
+	 */
+	info->pages = 0;
+	for (i = 0; i < ret; i++) {
+		if (!block_buffer[i])
+			break;
+		info->pages++;
+	}
+	if (!info->pages) {
+		dev_err(&client->dev, "No rails configured\n");
+		ret = -ENODEV;
+		goto out;
+	}
+	dev_info(&client->dev, "%d rails configured\n", info->pages);
+
+	/*
+	 * Set PHASE registers on all pages to 0xff to ensure that phase
+	 * specific commands will apply to all phases of a given page (rail).
+	 * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.
+	 * READ_IOUT will return the sum of currents of all phases of a rail,
+	 * and READ_TEMPERATURE2 will return the maximum temperature detected
+	 * for the the phases of the rail.
+	 */
+	for (i = 0; i < info->pages; i++) {
+		/*
+		 * Setting PAGE & PHASE fails once in a while for no obvious
+		 * reason, so we need to retry a couple of times.
+		 */
+		for (j = 0; j < 3; j++) {
+			ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);
+			if (ret < 0)
+				continue;
+			ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,
+							0xff);
+			if (ret < 0)
+				continue;
+			break;
+		}
+		if (ret < 0) {
+			dev_err(&client->dev,
+				"Failed to initialize PHASE registers\n");
+			goto out;
+		}
+	}
+	if (info->pages > 1)
+		i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
+
+	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
+			PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
+			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+			PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |
+			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+
+	for (i = 1; i < info->pages; i++)
+		info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+			PMBUS_HAVE_POUT |
+			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
+
+	/* ucd9240 supports a single fan */
+	if (mid->driver_data == ucd9240)
+		info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;
+
+	ret = pmbus_do_probe(client, mid, info);
+	if (ret < 0)
+		goto out;
+	return 0;
+out:
+	kfree(info);
+	return ret;
+}
+
+static int ucd9200_remove(struct i2c_client *client)
+{
+	int ret;
+	const struct pmbus_driver_info *info;
+
+	info = pmbus_get_driver_info(client);
+	ret = pmbus_do_remove(client);
+	kfree(info);
+	return ret;
+}
+
+
+/* This is the driver that will be inserted */
+static struct i2c_driver ucd9200_driver = {
+	.driver = {
+		.name = "ucd9200",
+	},
+	.probe = ucd9200_probe,
+	.remove = ucd9200_remove,
+	.id_table = ucd9200_id,
+};
+
+static int __init ucd9200_init(void)
+{
+	return i2c_add_driver(&ucd9200_driver);
+}
+
+static void __exit ucd9200_exit(void)
+{
+	i2c_del_driver(&ucd9200_driver);
+}
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");
+MODULE_LICENSE("GPL");
+module_init(ucd9200_init);
+module_exit(ucd9200_exit);