Zev Weiss | d387d88 | 2021-12-08 13:37:02 -0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Delta AHE-50DC power shelf fan control module driver |
| 4 | * |
| 5 | * Copyright 2021 Zev Weiss <zev@bewilderbeest.net> |
| 6 | */ |
| 7 | |
| 8 | #include <linux/i2c.h> |
| 9 | #include <linux/kernel.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/pmbus.h> |
| 12 | |
| 13 | #include "pmbus.h" |
| 14 | |
| 15 | #define AHE50DC_PMBUS_READ_TEMP4 0xd0 |
| 16 | |
Zev Weiss | 08da09f | 2022-04-26 20:51:09 -0700 | [diff] [blame] | 17 | static int ahe50dc_fan_write_byte(struct i2c_client *client, int page, u8 value) |
| 18 | { |
| 19 | /* |
| 20 | * The CLEAR_FAULTS operation seems to sometimes (unpredictably, perhaps |
| 21 | * 5% of the time or so) trigger a problematic phenomenon in which the |
| 22 | * fan speeds surge momentarily and at least some (perhaps all?) of the |
| 23 | * system's power outputs experience a glitch. |
| 24 | * |
| 25 | * However, according to Delta it should be OK to simply not send any |
| 26 | * CLEAR_FAULTS commands (the device doesn't seem to be capable of |
| 27 | * reporting any faults anyway), so just blackhole them unconditionally. |
| 28 | */ |
| 29 | return value == PMBUS_CLEAR_FAULTS ? -EOPNOTSUPP : -ENODATA; |
| 30 | } |
| 31 | |
Zev Weiss | d387d88 | 2021-12-08 13:37:02 -0800 | [diff] [blame] | 32 | static int ahe50dc_fan_read_word_data(struct i2c_client *client, int page, int phase, int reg) |
| 33 | { |
| 34 | /* temp1 in (virtual) page 1 is remapped to mfr-specific temp4 */ |
| 35 | if (page == 1) { |
| 36 | if (reg == PMBUS_READ_TEMPERATURE_1) |
| 37 | return i2c_smbus_read_word_data(client, AHE50DC_PMBUS_READ_TEMP4); |
| 38 | return -EOPNOTSUPP; |
| 39 | } |
| 40 | |
| 41 | /* |
| 42 | * There's a fairly limited set of commands this device actually |
| 43 | * supports, so here we block attempts to read anything else (which |
| 44 | * return 0xffff and would cause confusion elsewhere). |
| 45 | */ |
| 46 | switch (reg) { |
| 47 | case PMBUS_STATUS_WORD: |
| 48 | case PMBUS_FAN_COMMAND_1: |
| 49 | case PMBUS_FAN_COMMAND_2: |
| 50 | case PMBUS_FAN_COMMAND_3: |
| 51 | case PMBUS_FAN_COMMAND_4: |
| 52 | case PMBUS_STATUS_FAN_12: |
| 53 | case PMBUS_STATUS_FAN_34: |
| 54 | case PMBUS_READ_VIN: |
| 55 | case PMBUS_READ_TEMPERATURE_1: |
| 56 | case PMBUS_READ_TEMPERATURE_2: |
| 57 | case PMBUS_READ_TEMPERATURE_3: |
| 58 | case PMBUS_READ_FAN_SPEED_1: |
| 59 | case PMBUS_READ_FAN_SPEED_2: |
| 60 | case PMBUS_READ_FAN_SPEED_3: |
| 61 | case PMBUS_READ_FAN_SPEED_4: |
| 62 | return -ENODATA; |
| 63 | default: |
| 64 | return -EOPNOTSUPP; |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | static struct pmbus_driver_info ahe50dc_fan_info = { |
| 69 | .pages = 2, |
| 70 | .format[PSC_FAN] = direct, |
| 71 | .format[PSC_TEMPERATURE] = direct, |
| 72 | .format[PSC_VOLTAGE_IN] = direct, |
| 73 | .m[PSC_FAN] = 1, |
| 74 | .b[PSC_FAN] = 0, |
| 75 | .R[PSC_FAN] = 0, |
| 76 | .m[PSC_TEMPERATURE] = 1, |
| 77 | .b[PSC_TEMPERATURE] = 0, |
| 78 | .R[PSC_TEMPERATURE] = 1, |
| 79 | .m[PSC_VOLTAGE_IN] = 1, |
| 80 | .b[PSC_VOLTAGE_IN] = 0, |
| 81 | .R[PSC_VOLTAGE_IN] = 3, |
| 82 | .func[0] = PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 | |
| 83 | PMBUS_HAVE_VIN | PMBUS_HAVE_FAN12 | PMBUS_HAVE_FAN34 | |
| 84 | PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_STATUS_FAN34 | PMBUS_PAGE_VIRTUAL, |
| 85 | .func[1] = PMBUS_HAVE_TEMP | PMBUS_PAGE_VIRTUAL, |
Zev Weiss | 08da09f | 2022-04-26 20:51:09 -0700 | [diff] [blame] | 86 | .write_byte = ahe50dc_fan_write_byte, |
Zev Weiss | d387d88 | 2021-12-08 13:37:02 -0800 | [diff] [blame] | 87 | .read_word_data = ahe50dc_fan_read_word_data, |
| 88 | }; |
| 89 | |
| 90 | /* |
| 91 | * CAPABILITY returns 0xff, which appears to be this device's way indicating |
| 92 | * it doesn't support something (and if we enable I2C_CLIENT_PEC on seeing bit |
| 93 | * 7 being set it generates bad PECs, so let's not go there). |
| 94 | */ |
| 95 | static struct pmbus_platform_data ahe50dc_fan_data = { |
| 96 | .flags = PMBUS_NO_CAPABILITY, |
| 97 | }; |
| 98 | |
| 99 | static int ahe50dc_fan_probe(struct i2c_client *client) |
| 100 | { |
| 101 | client->dev.platform_data = &ahe50dc_fan_data; |
| 102 | return pmbus_do_probe(client, &ahe50dc_fan_info); |
| 103 | } |
| 104 | |
| 105 | static const struct i2c_device_id ahe50dc_fan_id[] = { |
| 106 | { "ahe50dc_fan" }, |
| 107 | { } |
| 108 | }; |
| 109 | MODULE_DEVICE_TABLE(i2c, ahe50dc_fan_id); |
| 110 | |
| 111 | static const struct of_device_id __maybe_unused ahe50dc_fan_of_match[] = { |
| 112 | { .compatible = "delta,ahe50dc-fan" }, |
| 113 | { } |
| 114 | }; |
| 115 | MODULE_DEVICE_TABLE(of, ahe50dc_fan_of_match); |
| 116 | |
| 117 | static struct i2c_driver ahe50dc_fan_driver = { |
| 118 | .driver = { |
| 119 | .name = "ahe50dc_fan", |
| 120 | .of_match_table = of_match_ptr(ahe50dc_fan_of_match), |
| 121 | }, |
Uwe Kleine-König | 1975d16 | 2023-05-05 15:17:18 +0200 | [diff] [blame] | 122 | .probe = ahe50dc_fan_probe, |
Zev Weiss | d387d88 | 2021-12-08 13:37:02 -0800 | [diff] [blame] | 123 | .id_table = ahe50dc_fan_id, |
| 124 | }; |
| 125 | module_i2c_driver(ahe50dc_fan_driver); |
| 126 | |
| 127 | MODULE_AUTHOR("Zev Weiss <zev@bewilderbeest.net>"); |
| 128 | MODULE_DESCRIPTION("Driver for Delta AHE-50DC power shelf fan control module"); |
| 129 | MODULE_LICENSE("GPL"); |
| 130 | MODULE_IMPORT_NS(PMBUS); |