diff options
Diffstat (limited to 'drivers/hwmon/pmbus.c')
| -rw-r--r-- | drivers/hwmon/pmbus.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus.c b/drivers/hwmon/pmbus.c new file mode 100644 index 00000000000..98e2e28899e --- /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); |