From 4e63e9b77422aae8e7411ddc7a8458c2585c86df Mon Sep 17 00:00:00 2001 From: Paul Pawlowski Date: Sun, 17 Nov 2019 23:12:18 +0100 Subject: [PATCH 6/6] applesmc: fan support on T2 Macs T2 Macs changed the fan values from shorts to floats, and changed the fan manual override setting from a bitmask to a per-fan boolean named F0Md (thanks to @kleuter for mentioning it). A minimal soft-float implementation has been written for convert floats to integers (and vice versa). Signed-off-by: Aun-Ali Zaidi --- drivers/hwmon/applesmc.c | 119 +++++++++++++++++++++++++++++++++------ 1 file changed, 102 insertions(+), 17 deletions(-) diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c index 2d23bb9ad9dd..0938227be612 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -87,6 +87,7 @@ #define FAN_ID_FMT "F%dID" /* r-o char[16] */ #define TEMP_SENSOR_TYPE "sp78" +#define FLOAT_TYPE "flt " /* List of keys used to read/write fan speeds */ static const char *const fan_speed_fmt[] = { @@ -96,6 +97,7 @@ static const char *const fan_speed_fmt[] = { "F%dSf", /* safe speed - not all models */ "F%dTg", /* target speed (manual: rw) */ }; +#define FAN_MANUAL_FMT "F%dMd" #define INIT_TIMEOUT_MSECS 5000 /* wait up to 5s for device init ... */ #define INIT_WAIT_MSECS 50 /* ... in 50ms increments */ @@ -734,6 +736,42 @@ static int applesmc_read_s16(struct applesmc_device *smc, return 0; } +/** + * applesmc_float_to_u32 - Retrieve the integral part of a float. + * This is needed because Apple made fans use float values in the T2. + * The fractional point is not significantly useful though, and the integral + * part can be easily extracted. + */ +static inline u32 applesmc_float_to_u32(u32 d) +{ + u8 sign = (u8) ((d >> 31) & 1); + s32 exp = (s32) ((d >> 23) & 0xff) - 0x7f; + u32 fr = d & ((1u << 23) - 1); + + if (sign || exp < 0) + return 0; + + return (u32) ((1u << exp) + (fr >> (23 - exp))); +} + +/** + * applesmc_u32_to_float - Convert an u32 into a float. + * See applesmc_float_to_u32 for a rationale. + */ +static inline u32 applesmc_u32_to_float(u32 d) +{ + u32 dc = d, bc = 0, exp; + + if (!d) + return 0; + + while (dc >>= 1) + ++bc; + exp = 0x7f + bc; + + return (u32) ((exp << 23) | + ((d << (23 - (exp - 0x7f))) & ((1u << 23) - 1))); +} /* * applesmc_device_init - initialize the accelerometer. Can sleep. */ @@ -1242,6 +1280,7 @@ static ssize_t applesmc_show_fan_speed(struct device *dev, struct device_attribute *attr, char *sysfsbuf) { struct applesmc_device *smc = dev_get_drvdata(dev); + const struct applesmc_entry *entry; int ret; unsigned int speed = 0; char newkey[5]; @@ -1250,11 +1289,21 @@ static ssize_t applesmc_show_fan_speed(struct device *dev, scnprintf(newkey, sizeof(newkey), fan_speed_fmt[to_option(attr)], to_index(attr)); - ret = applesmc_read_key(smc, newkey, buffer, 2); + entry = applesmc_get_entry_by_key(smc, newkey); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + if (!strcmp(entry->type, FLOAT_TYPE)) { + ret = applesmc_read_entry(smc, entry, (u8 *) &speed, 4); + speed = applesmc_float_to_u32(speed); + } else { + ret = applesmc_read_entry(smc, entry, buffer, 2); + speed = ((buffer[0] << 8 | buffer[1]) >> 2); + } + if (ret) return ret; - speed = ((buffer[0] << 8 | buffer[1]) >> 2); return sysfs_emit(sysfsbuf, "%u\n", speed); } @@ -1263,6 +1312,7 @@ static ssize_t applesmc_store_fan_speed(struct device *dev, const char *sysfsbuf, size_t count) { struct applesmc_device *smc = dev_get_drvdata(dev); + const struct applesmc_entry *entry; int ret; unsigned long speed; char newkey[5]; @@ -1274,9 +1324,18 @@ static ssize_t applesmc_store_fan_speed(struct device *dev, scnprintf(newkey, sizeof(newkey), fan_speed_fmt[to_option(attr)], to_index(attr)); - buffer[0] = (speed >> 6) & 0xff; - buffer[1] = (speed << 2) & 0xff; - ret = applesmc_write_key(smc, newkey, buffer, 2); + entry = applesmc_get_entry_by_key(smc, newkey); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + if (!strcmp(entry->type, FLOAT_TYPE)) { + speed = applesmc_u32_to_float(speed); + ret = applesmc_write_entry(smc, entry, (u8 *) &speed, 4); + } else { + buffer[0] = (speed >> 6) & 0xff; + buffer[1] = (speed << 2) & 0xff; + ret = applesmc_write_key(smc, newkey, buffer, 2); + } if (ret) return ret; @@ -1291,12 +1350,26 @@ static ssize_t applesmc_show_fan_manual(struct device *dev, int ret; u16 manual = 0; u8 buffer[2]; + char newkey[5]; + bool has_newkey = false; + + scnprintf(newkey, sizeof(newkey), FAN_MANUAL_FMT, to_index(attr)); + + ret = applesmc_has_key(smc, newkey, &has_newkey); + if (ret) + return ret; + + if (has_newkey) { + ret = applesmc_read_key(smc, newkey, buffer, 1); + manual = buffer[0]; + } else { + ret = applesmc_read_key(smc, FANS_MANUAL, buffer, 2); + manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01; + } - ret = applesmc_read_key(smc, FANS_MANUAL, buffer, 2); if (ret) return ret; - manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01; return sysfs_emit(sysfsbuf, "%d\n", manual); } @@ -1307,27 +1380,39 @@ static ssize_t applesmc_store_fan_manual(struct device *dev, struct applesmc_device *smc = dev_get_drvdata(dev); int ret; u8 buffer[2]; + char newkey[5]; + bool has_newkey = false; unsigned long input; u16 val; if (kstrtoul(sysfsbuf, 10, &input) < 0) return -EINVAL; - ret = applesmc_read_key(smc, FANS_MANUAL, buffer, 2); + scnprintf(newkey, sizeof(newkey), FAN_MANUAL_FMT, to_index(attr)); + + ret = applesmc_has_key(smc, newkey, &has_newkey); if (ret) - goto out; + return ret; - val = (buffer[0] << 8 | buffer[1]); + if (has_newkey) { + buffer[0] = input & 1; + ret = applesmc_write_key(smc, newkey, buffer, 1); + } else { + ret = applesmc_read_key(smc, FANS_MANUAL, buffer, 2); + val = (buffer[0] << 8 | buffer[1]); + if (ret) + goto out; - if (input) - val = val | (0x01 << to_index(attr)); - else - val = val & ~(0x01 << to_index(attr)); + if (input) + val = val | (0x01 << to_index(attr)); + else + val = val & ~(0x01 << to_index(attr)); - buffer[0] = (val >> 8) & 0xFF; - buffer[1] = val & 0xFF; + buffer[0] = (val >> 8) & 0xFF; + buffer[1] = val & 0xFF; - ret = applesmc_write_key(smc, FANS_MANUAL, buffer, 2); + ret = applesmc_write_key(smc, FANS_MANUAL, buffer, 2); + } out: if (ret) -- 2.30.0