THIS PATCH IS A RESEND OF THIS PATCH: https://lore.kernel.org/all/20250114045256.3211-1-evepolonium@xxxxxxxxx/ This patch adds support for fan control on T2 Macs in the applesmc driver. It introduces functions to handle floating-point fan speed values (which are required by t2 chips). The fan speed reading and writing are updated to support both integer and floating-point values. The fan manual control is also updated to handle T2 Mac-specific keys. Guenter Roeck asked "Does this limit still apply?" so yes the limit still applies. Changes since v3: --- fixed error by kernel test robot about FIELD_GET and FIELD_PREP by by adding linux/bitfield.h Co-developed-by: Aun-Ali Zaidi <admin@xxxxxxxxxx> Signed-off-by: Aun-Ali Zaidi <admin@xxxxxxxxxx> Signed-off-by: Atharva Tiwari <evepolonium@xxxxxxxxx> --- drivers/hwmon/applesmc.c | 123 ++++++++++++++++++++++++++++++++------- 1 file changed, 101 insertions(+), 22 deletions(-) diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c index fc6d6a9053ce..f899b17dcc1e 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -33,6 +33,7 @@ #include <linux/workqueue.h> #include <linux/err.h> #include <linux/bits.h> +#include <linux/bitfield.h> /* data port used by Apple SMC */ #define APPLESMC_DATA_PORT 0x300 @@ -74,6 +75,7 @@ #define FAN_ID_FMT "F%dID" /* r-o char[16] */ #define TEMP_SENSOR_TYPE "sp78" +#define FAN_MANUAL_FMT "F%dMd" /* List of keys used to read/write fan speeds */ static const char *const fan_speed_fmt[] = { @@ -511,6 +513,32 @@ static int applesmc_read_s16(const char *key, s16 *value) return 0; } +static inline u32 applesmc_float_to_u32(u32 d) +{ + u8 sign = FIELD_GET(BIT(31), d); + s32 exp = FIELD_GET(BIT_MASK(8) << 23, d) - 0x7F; + u32 fr = d & ((1u << 23) - 1); + + if (sign || exp < 0) + return 0; + + return BIT(exp) + (fr >> (23 - exp)); +} + +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 FIELD_PREP(BIT_MASK(8) << 23, exp) | + (d << (23 - (exp - 0x7F)) & BIT_MASK(23)); + +} + /* * applesmc_device_init - initialize the accelerometer. Can sleep. */ @@ -841,16 +869,33 @@ static ssize_t applesmc_show_fan_speed(struct device *dev, int ret; unsigned int speed = 0; char newkey[5]; - u8 buffer[2]; + u8 buffer[4] = {0}; + const struct applesmc_entry *entry; + bool is_float = false; scnprintf(newkey, sizeof(newkey), fan_speed_fmt[to_option(attr)], to_index(attr)); - ret = applesmc_read_key(newkey, buffer, 2); + entry = applesmc_get_entry_by_key(newkey); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + if (!strcmp(entry->type, "flt")) + is_float = true; + + if (is_float) { + ret = applesmc_read_entry(entry, buffer, 4); + if (ret) + return ret; + speed = applesmc_float_to_u32(*(u32 *)buffer); + } else { + ret = applesmc_read_entry(entry, buffer, 2); + if (ret) + return ret; + 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); } @@ -861,7 +906,9 @@ static ssize_t applesmc_store_fan_speed(struct device *dev, int ret; unsigned long speed; char newkey[5]; - u8 buffer[2]; + u8 buffer[4]; + const struct applesmc_entry *entry; + bool is_float = false; if (kstrtoul(sysfsbuf, 10, &speed) < 0 || speed >= 0x4000) return -EINVAL; /* Bigger than a 14-bit value */ @@ -869,9 +916,20 @@ 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(newkey, buffer, 2); + entry = applesmc_get_entry_by_key(newkey); + if (IS_ERR(entry)) + return PTR_ERR(entry); + if (!strcmp(entry->type, "flt")) + is_float = true; + + if (is_float) { + *(u32 *)buffer = applesmc_u32_to_float(speed); + ret = applesmc_write_entry(entry, buffer, 4); + } else { + buffer[0] = (speed >> 6) & 0xff; + buffer[1] = (speed << 2) & 0xff; + ret = applesmc_write_entry((const struct applesmc_entry *)newkey, buffer, 2); + } if (ret) return ret; @@ -885,12 +943,23 @@ 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(newkey, &has_newkey); + if (has_newkey) { + ret = applesmc_read_key(newkey, buffer, 1); + manual = buffer[0] & 0x01; + } else { + ret = applesmc_read_key(FANS_MANUAL, buffer, 2); + manual = ((buffer[0] << 8 | buffer[1]) >> to_index(attr)) & 0x01; + } - ret = applesmc_read_key(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); } @@ -900,28 +969,38 @@ static ssize_t applesmc_store_fan_manual(struct device *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(FANS_MANUAL, buffer, 2); - if (ret) - goto out; - - val = (buffer[0] << 8 | buffer[1]); + scnprintf(newkey, sizeof(newkey), FAN_MANUAL_FMT, to_index(attr)); - if (input) - val = val | (0x01 << to_index(attr)); - else - val = val & ~(0x01 << to_index(attr)); + ret = applesmc_has_key(newkey, &has_newkey); + if (ret) + return ret; + if (has_newkey) { + buffer[0] = (input != 0x00); + ret = applesmc_write_key(newkey, buffer, 1); + } else { + ret = applesmc_read_key(FANS_MANUAL, buffer, 2); + val = (buffer[0] << 8 | buffer[1]); + if (ret) + goto out; - buffer[0] = (val >> 8) & 0xFF; - buffer[1] = val & 0xFF; + if (input) + val = val | (0x01 << to_index(attr)); + else + val = val & ~(0x01 << to_index(attr)); - ret = applesmc_write_key(FANS_MANUAL, buffer, 2); + buffer[0] = (val >> 8) & 0xFF; + buffer[1] = val & 0xFF; + ret = applesmc_write_key(FANS_MANUAL, buffer, 2); + } out: if (ret) return ret; -- 2.39.5
