hwmon: PMBus device driver
This driver adds support for hardware monitoring features of various PMBus
devices.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
diff --git a/drivers/hwmon/pmbus.c b/drivers/hwmon/pmbus.c
new file mode 100644
index 0000000..98e2e28
--- /dev/null
+++ b/drivers/hwmon/pmbus.c
@@ -0,0 +1,203 @@
+/*
+ * Hardware monitoring driver for PMBus devices
+ *
+ * Copyright (c) 2010, 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/mutex.h>
+#include <linux/i2c.h>
+#include "pmbus.h"
+
+/*
+ * Find sensor groups and status registers on each page.
+ */
+static void pmbus_find_sensor_groups(struct i2c_client *client,
+ struct pmbus_driver_info *info)
+{
+ int page;
+
+ /* Sensors detected on page 0 only */
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_VIN))
+ info->func[0] |= PMBUS_HAVE_VIN;
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_VCAP))
+ info->func[0] |= PMBUS_HAVE_VCAP;
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_IIN))
+ info->func[0] |= PMBUS_HAVE_IIN;
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_PIN))
+ info->func[0] |= PMBUS_HAVE_PIN;
+ if (info->func[0]
+ && pmbus_check_byte_register(client, 0, PMBUS_STATUS_INPUT))
+ info->func[0] |= PMBUS_HAVE_STATUS_INPUT;
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_1)) {
+ info->func[0] |= PMBUS_HAVE_FAN12;
+ if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_12))
+ info->func[0] |= PMBUS_HAVE_STATUS_FAN12;
+ }
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_FAN_SPEED_3)) {
+ info->func[0] |= PMBUS_HAVE_FAN34;
+ if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_34))
+ info->func[0] |= PMBUS_HAVE_STATUS_FAN34;
+ }
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1)) {
+ info->func[0] |= PMBUS_HAVE_TEMP;
+ if (pmbus_check_byte_register(client, 0,
+ PMBUS_STATUS_TEMPERATURE))
+ info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
+ }
+
+ /* Sensors detected on all pages */
+ for (page = 0; page < info->pages; page++) {
+ if (pmbus_check_word_register(client, page, PMBUS_READ_VOUT)) {
+ info->func[page] |= PMBUS_HAVE_VOUT;
+ if (pmbus_check_byte_register(client, page,
+ PMBUS_STATUS_VOUT))
+ info->func[page] |= PMBUS_HAVE_STATUS_VOUT;
+ }
+ if (pmbus_check_word_register(client, page, PMBUS_READ_IOUT)) {
+ info->func[page] |= PMBUS_HAVE_IOUT;
+ if (pmbus_check_byte_register(client, 0,
+ PMBUS_STATUS_IOUT))
+ info->func[page] |= PMBUS_HAVE_STATUS_IOUT;
+ }
+ if (pmbus_check_word_register(client, page, PMBUS_READ_POUT))
+ info->func[page] |= PMBUS_HAVE_POUT;
+ }
+}
+
+/*
+ * Identify chip parameters.
+ */
+static int pmbus_identify(struct i2c_client *client,
+ struct pmbus_driver_info *info)
+{
+ if (!info->pages) {
+ /*
+ * Check if the PAGE command is supported. If it is,
+ * keep setting the page number until it fails or until the
+ * maximum number of pages has been reached. Assume that
+ * this is the number of pages supported by the chip.
+ */
+ if (pmbus_check_byte_register(client, 0, PMBUS_PAGE)) {
+ int page;
+
+ for (page = 1; page < PMBUS_PAGES; page++) {
+ if (pmbus_set_page(client, page) < 0)
+ break;
+ }
+ pmbus_set_page(client, 0);
+ info->pages = page;
+ } else {
+ info->pages = 1;
+ }
+ }
+
+ /*
+ * We should check if the COEFFICIENTS register is supported.
+ * If it is, and the chip is configured for direct mode, we can read
+ * the coefficients from the chip, one set per group of sensor
+ * registers.
+ *
+ * To do this, we will need access to a chip which actually supports the
+ * COEFFICIENTS command, since the command is too complex to implement
+ * without testing it.
+ */
+
+ /* Try to find sensor groups */
+ pmbus_find_sensor_groups(client, info);
+
+ return 0;
+}
+
+static int pmbus_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct pmbus_driver_info *info;
+ int ret;
+
+ info = kzalloc(sizeof(struct pmbus_driver_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->pages = id->driver_data;
+ info->identify = pmbus_identify;
+
+ ret = pmbus_do_probe(client, id, info);
+ if (ret < 0)
+ goto out;
+ return 0;
+
+out:
+ kfree(info);
+ return ret;
+}
+
+static int pmbus_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;
+}
+
+/*
+ * Use driver_data to set the number of pages supported by the chip.
+ */
+static const struct i2c_device_id pmbus_id[] = {
+ {"bmr450", 1},
+ {"bmr451", 1},
+ {"bmr453", 1},
+ {"bmr454", 1},
+ {"ltc2978", 8},
+ {"pmbus", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, pmbus_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver pmbus_driver = {
+ .driver = {
+ .name = "pmbus",
+ },
+ .probe = pmbus_probe,
+ .remove = pmbus_remove,
+ .id_table = pmbus_id,
+};
+
+static int __init pmbus_init(void)
+{
+ return i2c_add_driver(&pmbus_driver);
+}
+
+static void __exit pmbus_exit(void)
+{
+ i2c_del_driver(&pmbus_driver);
+}
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("Generic PMBus driver");
+MODULE_LICENSE("GPL");
+module_init(pmbus_init);
+module_exit(pmbus_exit);