diff options
Diffstat (limited to 'drivers/hwmon/pmbus/delta-ahe50dc-fan.c')
| -rw-r--r-- | drivers/hwmon/pmbus/delta-ahe50dc-fan.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/delta-ahe50dc-fan.c b/drivers/hwmon/pmbus/delta-ahe50dc-fan.c new file mode 100644 index 000000000..f546f0c12 --- /dev/null +++ b/drivers/hwmon/pmbus/delta-ahe50dc-fan.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Delta AHE-50DC power shelf fan control module driver + * + * Copyright 2021 Zev Weiss <zev@bewilderbeest.net> + */ + +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pmbus.h> + +#include "pmbus.h" + +#define AHE50DC_PMBUS_READ_TEMP4 0xd0 + +static int ahe50dc_fan_write_byte(struct i2c_client *client, int page, u8 value) +{ + /* + * The CLEAR_FAULTS operation seems to sometimes (unpredictably, perhaps + * 5% of the time or so) trigger a problematic phenomenon in which the + * fan speeds surge momentarily and at least some (perhaps all?) of the + * system's power outputs experience a glitch. + * + * However, according to Delta it should be OK to simply not send any + * CLEAR_FAULTS commands (the device doesn't seem to be capable of + * reporting any faults anyway), so just blackhole them unconditionally. + */ + return value == PMBUS_CLEAR_FAULTS ? -EOPNOTSUPP : -ENODATA; +} + +static int ahe50dc_fan_read_word_data(struct i2c_client *client, int page, int phase, int reg) +{ + /* temp1 in (virtual) page 1 is remapped to mfr-specific temp4 */ + if (page == 1) { + if (reg == PMBUS_READ_TEMPERATURE_1) + return i2c_smbus_read_word_data(client, AHE50DC_PMBUS_READ_TEMP4); + return -EOPNOTSUPP; + } + + /* + * There's a fairly limited set of commands this device actually + * supports, so here we block attempts to read anything else (which + * return 0xffff and would cause confusion elsewhere). + */ + switch (reg) { + case PMBUS_STATUS_WORD: + case PMBUS_FAN_COMMAND_1: + case PMBUS_FAN_COMMAND_2: + case PMBUS_FAN_COMMAND_3: + case PMBUS_FAN_COMMAND_4: + case PMBUS_STATUS_FAN_12: + case PMBUS_STATUS_FAN_34: + case PMBUS_READ_VIN: + case PMBUS_READ_TEMPERATURE_1: + case PMBUS_READ_TEMPERATURE_2: + case PMBUS_READ_TEMPERATURE_3: + case PMBUS_READ_FAN_SPEED_1: + case PMBUS_READ_FAN_SPEED_2: + case PMBUS_READ_FAN_SPEED_3: + case PMBUS_READ_FAN_SPEED_4: + return -ENODATA; + default: + return -EOPNOTSUPP; + } +} + +static struct pmbus_driver_info ahe50dc_fan_info = { + .pages = 2, + .format[PSC_FAN] = direct, + .format[PSC_TEMPERATURE] = direct, + .format[PSC_VOLTAGE_IN] = direct, + .m[PSC_FAN] = 1, + .b[PSC_FAN] = 0, + .R[PSC_FAN] = 0, + .m[PSC_TEMPERATURE] = 1, + .b[PSC_TEMPERATURE] = 0, + .R[PSC_TEMPERATURE] = 1, + .m[PSC_VOLTAGE_IN] = 1, + .b[PSC_VOLTAGE_IN] = 0, + .R[PSC_VOLTAGE_IN] = 3, + .func[0] = PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | + PMBUS_HAVE_VIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_FAN34 | + PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_STATUS_FAN34 | PMBUS_PAGE_VIRTUAL, + .func[1] = PMBUS_HAVE_TEMP | PMBUS_PAGE_VIRTUAL, + .write_byte = ahe50dc_fan_write_byte, + .read_word_data = ahe50dc_fan_read_word_data, +}; + +/* + * CAPABILITY returns 0xff, which appears to be this device's way indicating + * it doesn't support something (and if we enable I2C_CLIENT_PEC on seeing bit + * 7 being set it generates bad PECs, so let's not go there). + */ +static struct pmbus_platform_data ahe50dc_fan_data = { + .flags = PMBUS_NO_CAPABILITY, +}; + +static int ahe50dc_fan_probe(struct i2c_client *client) +{ + client->dev.platform_data = &ahe50dc_fan_data; + return pmbus_do_probe(client, &ahe50dc_fan_info); +} + +static const struct i2c_device_id ahe50dc_fan_id[] = { + { "ahe50dc_fan" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ahe50dc_fan_id); + +static const struct of_device_id __maybe_unused ahe50dc_fan_of_match[] = { + { .compatible = "delta,ahe50dc-fan" }, + { } +}; +MODULE_DEVICE_TABLE(of, ahe50dc_fan_of_match); + +static struct i2c_driver ahe50dc_fan_driver = { + .driver = { + .name = "ahe50dc_fan", + .of_match_table = of_match_ptr(ahe50dc_fan_of_match), + }, + .probe_new = ahe50dc_fan_probe, + .id_table = ahe50dc_fan_id, +}; +module_i2c_driver(ahe50dc_fan_driver); + +MODULE_AUTHOR("Zev Weiss <zev@bewilderbeest.net>"); +MODULE_DESCRIPTION("Driver for Delta AHE-50DC power shelf fan control module"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(PMBUS); |