diff --git a/Documentation/hwmon/max31785 b/Documentation/hwmon/max31785 index 45fb6093dec2..7b0a0a8cdb6b 100644 --- a/Documentation/hwmon/max31785 +++ b/Documentation/hwmon/max31785 @@ -32,6 +32,7 @@ Sysfs attributes fan[1-4]_alarm Fan alarm. fan[1-4]_fault Fan fault. fan[1-4]_input Fan RPM. +fan[1-4]_target Fan input target in[1-6]_crit Critical maximum output voltage in[1-6]_crit_alarm Output voltage critical high alarm @@ -44,6 +45,12 @@ in[1-6]_max_alarm Output voltage high alarm in[1-6]_min Minimum output voltage in[1-6]_min_alarm Output voltage low alarm +pwm[1-4] Fan target duty cycle (0..255) +pwm[1-4]_enable 0: Full-speed + 1: Manual PWM control + 2: Automatic PWM (tach-feedback RPM fan-control) + 3: Automatic closed-loop (temp-feedback fan-control) + temp[1-11]_crit Critical high temperature temp[1-11]_crit_alarm Chip temperature critical high alarm temp[1-11]_input Measured temperature diff --git a/drivers/hwmon/pmbus/max31785.c b/drivers/hwmon/pmbus/max31785.c index 9313849d5160..8706a696c89a 100644 --- a/drivers/hwmon/pmbus/max31785.c +++ b/drivers/hwmon/pmbus/max31785.c @@ -20,8 +20,136 @@ enum max31785_regs { #define MAX31785_NR_PAGES 23 +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, 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 reg) +{ + int rv; + + switch (reg) { + 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_FAN12 | PMBUS_HAVE_STATUS_FAN12 | PMBUS_HAVE_PWM12) #define MAX31785_TEMP_FUNCS \ (PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP) @@ -32,11 +160,19 @@ enum max31785_regs { static const struct pmbus_driver_info max31785_info = { .pages = MAX31785_NR_PAGES, + .write_word_data = max31785_write_word_data, + .read_word_data = max31785_read_word_data, + /* 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,