| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2017 IBM Corp. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/err.h> |
| #include <linux/i2c.h> |
| #include "pmbus.h" |
| |
| enum max31785_regs { |
| MFR_REVISION = 0x9b, |
| MFR_FAN_CONFIG = 0xf1, |
| }; |
| |
| #define MAX31785 0x3030 |
| #define MAX31785A 0x3040 |
| |
| #define MFR_FAN_CONFIG_DUAL_TACH BIT(12) |
| |
| #define MAX31785_NR_PAGES 23 |
| #define MAX31785_NR_FAN_PAGES 6 |
| |
| static int max31785_read_byte_data(struct i2c_client *client, int page, |
| int reg) |
| { |
| if (page < MAX31785_NR_PAGES) |
| return -ENODATA; |
| |
| switch (reg) { |
| case PMBUS_VOUT_MODE: |
| return -ENOTSUPP; |
| case PMBUS_FAN_CONFIG_12: |
| return pmbus_read_byte_data(client, page - MAX31785_NR_PAGES, |
| reg); |
| } |
| |
| return -ENODATA; |
| } |
| |
| static int max31785_write_byte(struct i2c_client *client, int page, u8 value) |
| { |
| if (page < MAX31785_NR_PAGES) |
| return -ENODATA; |
| |
| return -ENOTSUPP; |
| } |
| |
| static int max31785_read_long_data(struct i2c_client *client, int page, |
| int reg, u32 *data) |
| { |
| unsigned char cmdbuf[1]; |
| unsigned char rspbuf[4]; |
| int rc; |
| |
| struct i2c_msg msg[2] = { |
| { |
| .addr = client->addr, |
| .flags = 0, |
| .len = sizeof(cmdbuf), |
| .buf = cmdbuf, |
| }, |
| { |
| .addr = client->addr, |
| .flags = I2C_M_RD, |
| .len = sizeof(rspbuf), |
| .buf = rspbuf, |
| }, |
| }; |
| |
| cmdbuf[0] = reg; |
| |
| rc = pmbus_set_page(client, page, 0xff); |
| if (rc < 0) |
| return rc; |
| |
| rc = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg)); |
| if (rc < 0) |
| return rc; |
| |
| *data = (rspbuf[0] << (0 * 8)) | (rspbuf[1] << (1 * 8)) | |
| (rspbuf[2] << (2 * 8)) | (rspbuf[3] << (3 * 8)); |
| |
| return rc; |
| } |
| |
| static int max31785_get_pwm(struct i2c_client *client, int page) |
| { |
| int rv; |
| |
| rv = pmbus_get_fan_rate_device(client, page, 0, percent); |
| if (rv < 0) |
| return rv; |
| else if (rv >= 0x8000) |
| return 0; |
| else if (rv >= 0x2711) |
| return 0x2710; |
| |
| return rv; |
| } |
| |
| static int max31785_get_pwm_mode(struct i2c_client *client, int page) |
| { |
| int config; |
| int command; |
| |
| config = pmbus_read_byte_data(client, page, PMBUS_FAN_CONFIG_12); |
| if (config < 0) |
| return config; |
| |
| command = pmbus_read_word_data(client, page, 0xff, PMBUS_FAN_COMMAND_1); |
| if (command < 0) |
| return command; |
| |
| if (config & PB_FAN_1_RPM) |
| return (command >= 0x8000) ? 3 : 2; |
| |
| if (command >= 0x8000) |
| return 3; |
| else if (command >= 0x2711) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int max31785_read_word_data(struct i2c_client *client, int page, |
| int phase, int reg) |
| { |
| u32 val; |
| int rv; |
| |
| switch (reg) { |
| case PMBUS_READ_FAN_SPEED_1: |
| if (page < MAX31785_NR_PAGES) |
| return -ENODATA; |
| |
| rv = max31785_read_long_data(client, page - MAX31785_NR_PAGES, |
| reg, &val); |
| if (rv < 0) |
| return rv; |
| |
| rv = (val >> 16) & 0xffff; |
| break; |
| case PMBUS_FAN_COMMAND_1: |
| /* |
| * PMBUS_FAN_COMMAND_x is probed to judge whether or not to |
| * expose fan control registers. |
| * |
| * Don't expose fan_target attribute for virtual pages. |
| */ |
| rv = (page >= MAX31785_NR_PAGES) ? -ENOTSUPP : -ENODATA; |
| break; |
| case PMBUS_VIRT_PWM_1: |
| rv = max31785_get_pwm(client, page); |
| break; |
| case PMBUS_VIRT_PWM_ENABLE_1: |
| rv = max31785_get_pwm_mode(client, page); |
| break; |
| default: |
| rv = -ENODATA; |
| break; |
| } |
| |
| return rv; |
| } |
| |
| static inline u32 max31785_scale_pwm(u32 sensor_val) |
| { |
| /* |
| * The datasheet describes the accepted value range for manual PWM as |
| * [0, 0x2710], while the hwmon pwmX sysfs interface accepts values in |
| * [0, 255]. The MAX31785 uses DIRECT mode to scale the FAN_COMMAND |
| * registers and in PWM mode the coefficients are m=1, b=0, R=2. The |
| * important observation here is that 0x2710 == 10000 == 100 * 100. |
| * |
| * R=2 (== 10^2 == 100) accounts for scaling the value provided at the |
| * sysfs interface into the required hardware resolution, but it does |
| * not yet yield a value that we can write to the device (this initial |
| * scaling is handled by pmbus_data2reg()). Multiplying by 100 below |
| * translates the parameter value into the percentage units required by |
| * PMBus, and then we scale back by 255 as required by the hwmon pwmX |
| * interface to yield the percentage value at the appropriate |
| * resolution for hardware. |
| */ |
| return (sensor_val * 100) / 255; |
| } |
| |
| static int max31785_pwm_enable(struct i2c_client *client, int page, |
| u16 word) |
| { |
| int config = 0; |
| int rate; |
| |
| switch (word) { |
| case 0: |
| rate = 0x7fff; |
| break; |
| case 1: |
| rate = pmbus_get_fan_rate_cached(client, page, 0, percent); |
| if (rate < 0) |
| return rate; |
| rate = max31785_scale_pwm(rate); |
| break; |
| case 2: |
| config = PB_FAN_1_RPM; |
| rate = pmbus_get_fan_rate_cached(client, page, 0, rpm); |
| if (rate < 0) |
| return rate; |
| break; |
| case 3: |
| rate = 0xffff; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return pmbus_update_fan(client, page, 0, config, PB_FAN_1_RPM, rate); |
| } |
| |
| static int max31785_write_word_data(struct i2c_client *client, int page, |
| int reg, u16 word) |
| { |
| switch (reg) { |
| case PMBUS_VIRT_PWM_1: |
| return pmbus_update_fan(client, page, 0, 0, PB_FAN_1_RPM, |
| max31785_scale_pwm(word)); |
| case PMBUS_VIRT_PWM_ENABLE_1: |
| return max31785_pwm_enable(client, page, word); |
| default: |
| break; |
| } |
| |
| return -ENODATA; |
| } |
| |
| #define MAX31785_FAN_FUNCS \ |
| (PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_PWM12) |
| |
| #define MAX31785_TEMP_FUNCS \ |
| (PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP) |
| |
| #define MAX31785_VOUT_FUNCS \ |
| (PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT) |
| |
| static const struct pmbus_driver_info max31785_info = { |
| .pages = MAX31785_NR_PAGES, |
| |
| .write_word_data = max31785_write_word_data, |
| .read_byte_data = max31785_read_byte_data, |
| .read_word_data = max31785_read_word_data, |
| .write_byte = max31785_write_byte, |
| |
| /* RPM */ |
| .format[PSC_FAN] = direct, |
| .m[PSC_FAN] = 1, |
| .b[PSC_FAN] = 0, |
| .R[PSC_FAN] = 0, |
| /* PWM */ |
| .format[PSC_PWM] = direct, |
| .m[PSC_PWM] = 1, |
| .b[PSC_PWM] = 0, |
| .R[PSC_PWM] = 2, |
| .func[0] = MAX31785_FAN_FUNCS, |
| .func[1] = MAX31785_FAN_FUNCS, |
| .func[2] = MAX31785_FAN_FUNCS, |
| .func[3] = MAX31785_FAN_FUNCS, |
| .func[4] = MAX31785_FAN_FUNCS, |
| .func[5] = MAX31785_FAN_FUNCS, |
| |
| .format[PSC_TEMPERATURE] = direct, |
| .m[PSC_TEMPERATURE] = 1, |
| .b[PSC_TEMPERATURE] = 0, |
| .R[PSC_TEMPERATURE] = 2, |
| .func[6] = MAX31785_TEMP_FUNCS, |
| .func[7] = MAX31785_TEMP_FUNCS, |
| .func[8] = MAX31785_TEMP_FUNCS, |
| .func[9] = MAX31785_TEMP_FUNCS, |
| .func[10] = MAX31785_TEMP_FUNCS, |
| .func[11] = MAX31785_TEMP_FUNCS, |
| .func[12] = MAX31785_TEMP_FUNCS, |
| .func[13] = MAX31785_TEMP_FUNCS, |
| .func[14] = MAX31785_TEMP_FUNCS, |
| .func[15] = MAX31785_TEMP_FUNCS, |
| .func[16] = MAX31785_TEMP_FUNCS, |
| |
| .format[PSC_VOLTAGE_OUT] = direct, |
| .m[PSC_VOLTAGE_OUT] = 1, |
| .b[PSC_VOLTAGE_OUT] = 0, |
| .R[PSC_VOLTAGE_OUT] = 0, |
| .func[17] = MAX31785_VOUT_FUNCS, |
| .func[18] = MAX31785_VOUT_FUNCS, |
| .func[19] = MAX31785_VOUT_FUNCS, |
| .func[20] = MAX31785_VOUT_FUNCS, |
| .func[21] = MAX31785_VOUT_FUNCS, |
| .func[22] = MAX31785_VOUT_FUNCS, |
| }; |
| |
| static int max31785_configure_dual_tach(struct i2c_client *client, |
| struct pmbus_driver_info *info) |
| { |
| int ret; |
| int i; |
| |
| for (i = 0; i < MAX31785_NR_FAN_PAGES; i++) { |
| ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i); |
| if (ret < 0) |
| return ret; |
| |
| ret = i2c_smbus_read_word_data(client, MFR_FAN_CONFIG); |
| if (ret < 0) |
| return ret; |
| |
| if (ret & MFR_FAN_CONFIG_DUAL_TACH) { |
| int virtual = MAX31785_NR_PAGES + i; |
| |
| info->pages = virtual + 1; |
| info->func[virtual] |= PMBUS_HAVE_FAN12; |
| info->func[virtual] |= PMBUS_PAGE_VIRTUAL; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int max31785_probe(struct i2c_client *client) |
| { |
| struct device *dev = &client->dev; |
| struct pmbus_driver_info *info; |
| bool dual_tach = false; |
| s64 ret; |
| |
| if (!i2c_check_functionality(client->adapter, |
| I2C_FUNC_SMBUS_BYTE_DATA | |
| I2C_FUNC_SMBUS_WORD_DATA)) |
| return -ENODEV; |
| |
| info = devm_kzalloc(dev, sizeof(struct pmbus_driver_info), GFP_KERNEL); |
| if (!info) |
| return -ENOMEM; |
| |
| *info = max31785_info; |
| |
| ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 255); |
| if (ret < 0) |
| return ret; |
| |
| ret = i2c_smbus_read_word_data(client, MFR_REVISION); |
| if (ret < 0) |
| return ret; |
| |
| if (ret == MAX31785A) { |
| dual_tach = true; |
| } else if (ret == MAX31785) { |
| if (!strcmp("max31785a", client->name)) |
| dev_warn(dev, "Expected max3175a, found max31785: cannot provide secondary tachometer readings\n"); |
| } else { |
| return -ENODEV; |
| } |
| |
| if (dual_tach) { |
| ret = max31785_configure_dual_tach(client, info); |
| if (ret < 0) |
| return ret; |
| } |
| |
| return pmbus_do_probe(client, info); |
| } |
| |
| static const struct i2c_device_id max31785_id[] = { |
| { "max31785", 0 }, |
| { "max31785a", 0 }, |
| { }, |
| }; |
| |
| MODULE_DEVICE_TABLE(i2c, max31785_id); |
| |
| static const struct of_device_id max31785_of_match[] = { |
| { .compatible = "maxim,max31785" }, |
| { .compatible = "maxim,max31785a" }, |
| { }, |
| }; |
| |
| MODULE_DEVICE_TABLE(of, max31785_of_match); |
| |
| static struct i2c_driver max31785_driver = { |
| .driver = { |
| .name = "max31785", |
| .of_match_table = max31785_of_match, |
| }, |
| .probe_new = max31785_probe, |
| .remove = pmbus_do_remove, |
| .id_table = max31785_id, |
| }; |
| |
| module_i2c_driver(max31785_driver); |
| |
| MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>"); |
| MODULE_DESCRIPTION("PMBus driver for the Maxim MAX31785"); |
| MODULE_LICENSE("GPL"); |