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>

Documentation/hwmon/ucd9200

+Kernel driver ucd9200
+=====================
+
+Supported chips:
+  * TI UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, and UCD9248
+    Prefixes: 'ucd9220', 'ucd9222', 'ucd9224', 'ucd9240', 'ucd9244', 'ucd9246',
+	'ucd9248'
+    Addresses scanned: -
+    Datasheets:
+	http://focus.ti.com/lit/ds/symlink/ucd9220.pdf
+	http://focus.ti.com/lit/ds/symlink/ucd9222.pdf
+	http://focus.ti.com/lit/ds/symlink/ucd9224.pdf
+	http://focus.ti.com/lit/ds/symlink/ucd9240.pdf
+	http://focus.ti.com/lit/ds/symlink/ucd9244.pdf
+	http://focus.ti.com/lit/ds/symlink/ucd9246.pdf
+	http://focus.ti.com/lit/ds/symlink/ucd9248.pdf
+
+Author: Guenter Roeck <guenter.roeck@ericsson.com>
+
+
+Description
+-----------
+
+[From datasheets] UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, and
+UCD9248 are multi-rail, multi-phase synchronous buck digital PWM controllers
+designed for non-isolated DC/DC power applications. The devices integrate
+dedicated circuitry for DC/DC loop management with flash memory and a serial
+interface to support configuration, monitoring and management.
+
+This driver is a client driver to the core PMBus driver. Please see
+Documentation/hwmon/pmbus for details on PMBus client drivers.
+
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate the
+devices explicitly. Please see Documentation/i2c/instantiating-devices for
+details.
+
+
+Platform data support
+---------------------
+
+The driver supports standard PMBus driver platform data. Please see
+Documentation/hwmon/pmbus for details.
+
+
+Sysfs entries
+-------------
+
+The following attributes are supported. Limits are read-write; all other
+attributes are read-only.
+
+in1_label		"vin".
+in1_input		Measured voltage. From READ_VIN register.
+in1_min			Minumum Voltage. From VIN_UV_WARN_LIMIT register.
+in1_max			Maximum voltage. From VIN_OV_WARN_LIMIT register.
+in1_lcrit		Critical minumum Voltage. VIN_UV_FAULT_LIMIT register.
+in1_crit		Critical maximum voltage. From VIN_OV_FAULT_LIMIT register.
+in1_min_alarm		Voltage low alarm. From VIN_UV_WARNING status.
+in1_max_alarm		Voltage high alarm. From VIN_OV_WARNING status.
+in1_lcrit_alarm		Voltage critical low alarm. From VIN_UV_FAULT status.
+in1_crit_alarm		Voltage critical high alarm. From VIN_OV_FAULT status.
+
+in[2-5]_label		"vout[1-4]".
+in[2-5]_input		Measured voltage. From READ_VOUT register.
+in[2-5]_min		Minumum Voltage. From VOUT_UV_WARN_LIMIT register.
+in[2-5]_max		Maximum voltage. From VOUT_OV_WARN_LIMIT register.
+in[2-5]_lcrit		Critical minumum Voltage. VOUT_UV_FAULT_LIMIT register.
+in[2-5]_crit		Critical maximum voltage. From VOUT_OV_FAULT_LIMIT register.
+in[2-5]_min_alarm	Voltage low alarm. From VOLTAGE_UV_WARNING status.
+in[2-5]_max_alarm	Voltage high alarm. From VOLTAGE_OV_WARNING status.
+in[2-5]_lcrit_alarm	Voltage critical low alarm. From VOLTAGE_UV_FAULT status.
+in[2-5]_crit_alarm	Voltage critical high alarm. From VOLTAGE_OV_FAULT status.
+
+curr1_label		"iin".
+curr1_input		Measured current. From READ_IIN register.
+
+curr[2-5]_label		"iout[1-4]".
+curr[2-5]_input		Measured current. From READ_IOUT register.
+curr[2-5]_max		Maximum current. From IOUT_OC_WARN_LIMIT register.
+curr[2-5]_lcrit		Critical minumum output current. From IOUT_UC_FAULT_LIMIT
+			register.
+curr[2-5]_crit		Critical maximum current. From IOUT_OC_FAULT_LIMIT register.
+curr[2-5]_max_alarm	Current high alarm. From IOUT_OC_WARNING status.
+curr[2-5]_crit_alarm	Current critical high alarm. From IOUT_OC_FAULT status.
+
+power1_input		Measured input power. From READ_PIN register.
+power1_label		"pin"
+
+power[2-5]_input	Measured output power. From READ_POUT register.
+power[2-5]_label	"pout[1-4]"
+
+			The number of output voltage, current, and power
+			attribute sets is determined by the number of enabled
+			rails. See chip datasheets for details.
+
+temp[1-5]_input		Measured temperatures. From READ_TEMPERATURE_1 and
+		        READ_TEMPERATURE_2 registers.
+			temp1 is the chip internal temperature. temp[2-5] are
+			rail temperatures.  temp[2-5] attributes are only
+			created for enabled rails. See chip datasheets for
+			details.
+temp[1-5]_max		Maximum temperature. From OT_WARN_LIMIT register.
+temp[1-5]_crit		Critical high temperature. From OT_FAULT_LIMIT register.
+temp[1-5]_max_alarm	Temperature high alarm.
+temp[1-5]_crit_alarm	Temperature critical high alarm.
+
+fan1_input		Fan RPM. ucd9240 only.
+fan1_alarm		Fan alarm. ucd9240 only.
+fan1_fault		Fan fault. ucd9240 only.

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

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
 

drivers/hwmon/ucd9200.c

+/*
+ * 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);