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Diffstat (limited to 'include/linux/mfd/macsmc.h')
| -rw-r--r-- | include/linux/mfd/macsmc.h | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/include/linux/mfd/macsmc.h b/include/linux/mfd/macsmc.h new file mode 100644 index 000000000000..6b13f01a8592 --- /dev/null +++ b/include/linux/mfd/macsmc.h @@ -0,0 +1,279 @@ +/* SPDX-License-Identifier: GPL-2.0-only OR MIT */ +/* + * Apple SMC (System Management Controller) core definitions + * + * Copyright (C) The Asahi Linux Contributors + */ + +#ifndef _LINUX_MFD_MACSMC_H +#define _LINUX_MFD_MACSMC_H + +#include <linux/soc/apple/rtkit.h> + +/** + * typedef smc_key - Alias for u32 to be used for SMC keys + * + * SMC keys are 32bit integers containing packed ASCII characters in natural + * integer order, i.e. 0xAABBCCDD, which represent the FourCC ABCD. + * The SMC driver is designed with this assumption and ensures the right + * endianness is used when these are stored to memory and sent to or received + * from the actual SMC firmware (which can be done in either shared memory or + * as 64bit mailbox message on Apple Silicon). + * Internally, SMC stores these keys in a table sorted lexicographically and + * allows resolving an index into this table to the corresponding SMC key. + * Thus, storing keys as u32 is very convenient as it allows to e.g. use + * normal comparison operators which directly map to the natural order used + * by SMC firmware. + * + * This simple type alias is introduced to allow easy recognition of SMC key + * variables and arguments. + */ +typedef u32 smc_key; + +/** + * SMC_KEY - Convert FourCC SMC keys in source code to smc_key + * + * This macro can be used to easily define FourCC SMC keys in source code + * and convert these to u32 / smc_key, e.g. SMC_KEY(NTAP) will expand to + * 0x4e544150. + * + * @s: FourCC SMC key to be converted + */ +#define SMC_KEY(s) (smc_key)(_SMC_KEY(#s)) +#define _SMC_KEY(s) (((s)[0] << 24) | ((s)[1] << 16) | ((s)[2] << 8) | (s)[3]) + +#define APPLE_SMC_READABLE BIT(7) +#define APPLE_SMC_WRITABLE BIT(6) +#define APPLE_SMC_FUNCTION BIT(4) + +/** + * struct apple_smc_key_info - Information for a SMC key as returned by SMC + * @type_code: FourCC code indicating the type for this key. + * Known types: + * ch8*: ASCII string + * flag: Boolean, 1 or 0 + * flt: 32-bit single-precision IEEE 754 float + * hex: Binary data + * ioft: 64bit Unsigned fixed-point intger (48.16) + * {si,ui}{8,16,32,64}: Signed/Unsigned 8-/16-/32-/64-bit integer + * @size: Size of the buffer associated with this key + * @flags: Bitfield encoding flags (APPLE_SMC_{READABLE,WRITABLE,FUNCTION}) + */ +struct apple_smc_key_info { + u32 type_code; + u8 size; + u8 flags; +}; + +/** + * enum apple_smc_boot_stage - SMC boot stage + * @APPLE_SMC_BOOTING: SMC is booting + * @APPLE_SMC_INITIALIZED: SMC is initialized and ready to use + * @APPLE_SMC_ERROR_NO_SHMEM: Shared memory could not be initialized during boot + * @APPLE_SMC_ERROR_CRASHED: SMC has crashed + */ +enum apple_smc_boot_stage { + APPLE_SMC_BOOTING, + APPLE_SMC_INITIALIZED, + APPLE_SMC_ERROR_NO_SHMEM, + APPLE_SMC_ERROR_CRASHED +}; + +/** + * struct apple_smc + * @dev: Underlying device struct for the physical backend device + * @key_count: Number of available SMC keys + * @first_key: First valid SMC key + * @last_key: Last valid SMC key + * @event_handlers: Notifier call chain for events received from SMC + * @rtk: Pointer to Apple RTKit instance + * @init_done: Completion for initialization + * @boot_stage: Current boot stage of SMC + * @sram: Pointer to SRAM resource + * @sram_base: SRAM base address + * @shmem: RTKit shared memory structure for SRAM + * @msg_id: Current message id for commands, will be incremented for each command + * @atomic_mode: Flag set when atomic mode is entered + * @atomic_pending: Flag indicating pending atomic command + * @cmd_done: Completion for command execution in non-atomic mode + * @cmd_ret: Return value from SMC for last command + * @mutex: Mutex for non-atomic mode + * @lock: Spinlock for atomic mode + */ +struct apple_smc { + struct device *dev; + + u32 key_count; + smc_key first_key; + smc_key last_key; + + struct blocking_notifier_head event_handlers; + + struct apple_rtkit *rtk; + + struct completion init_done; + enum apple_smc_boot_stage boot_stage; + + struct resource *sram; + void __iomem *sram_base; + struct apple_rtkit_shmem shmem; + + unsigned int msg_id; + + bool atomic_mode; + bool atomic_pending; + struct completion cmd_done; + u64 cmd_ret; + + struct mutex mutex; + spinlock_t lock; +}; + +/** + * apple_smc_read - Read size bytes from given SMC key into buf + * @smc: Pointer to apple_smc struct + * @key: smc_key to be read + * @buf: Buffer into which size bytes of data will be read from SMC + * @size: Number of bytes to be read into buf + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_read(struct apple_smc *smc, smc_key key, void *buf, size_t size); + +/** + * apple_smc_write - Write size bytes into given SMC key from buf + * @smc: Pointer to apple_smc struct + * @key: smc_key data will be written to + * @buf: Buffer from which size bytes of data will be written to SMC + * @size: Number of bytes to be written + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_write(struct apple_smc *smc, smc_key key, void *buf, size_t size); + +/** + * apple_smc_enter_atomic - Enter atomic mode to be able to use apple_smc_write_atomic + * @smc: Pointer to apple_smc struct + * + * This function switches the SMC backend to atomic mode which allows the + * use of apple_smc_write_atomic while disabling *all* other functions. + * This is only used for shutdown/reboot which requires writing to a SMC + * key from atomic context. + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_enter_atomic(struct apple_smc *smc); + +/** + * apple_smc_write_atomic - Write size bytes into given SMC key from buf without sleeping + * @smc: Pointer to apple_smc struct + * @key: smc_key data will be written to + * @buf: Buffer from which size bytes of data will be written to SMC + * @size: Number of bytes to be written + * + * Note that this function will fail if apple_smc_enter_atomic hasn't been + * called before. + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_write_atomic(struct apple_smc *smc, smc_key key, void *buf, size_t size); + +/** + * apple_smc_rw - Write and then read using the given SMC key + * @smc: Pointer to apple_smc struct + * @key: smc_key data will be written to + * @wbuf: Buffer from which size bytes of data will be written to SMC + * @wsize: Number of bytes to be written + * @rbuf: Buffer to which size bytes of data will be read from SMC + * @rsize: Number of bytes to be read + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_rw(struct apple_smc *smc, smc_key key, void *wbuf, size_t wsize, + void *rbuf, size_t rsize); + +/** + * apple_smc_get_key_by_index - Given an index return the corresponding SMC key + * @smc: Pointer to apple_smc struct + * @index: Index to be resolved + * @key: Buffer for SMC key to be returned + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_get_key_by_index(struct apple_smc *smc, int index, smc_key *key); + +/** + * apple_smc_get_key_info - Get key information from SMC + * @smc: Pointer to apple_smc struct + * @key: Key to acquire information for + * @info: Pointer to struct apple_smc_key_info which will be filled + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_get_key_info(struct apple_smc *smc, smc_key key, struct apple_smc_key_info *info); + +/** + * apple_smc_key_exists - Check if the given SMC key exists + * @smc: Pointer to apple_smc struct + * @key: smc_key to be checked + * + * Return: True if the key exists, false otherwise + */ +static inline bool apple_smc_key_exists(struct apple_smc *smc, smc_key key) +{ + return apple_smc_get_key_info(smc, key, NULL) >= 0; +} + +#define APPLE_SMC_TYPE_OPS(type) \ + static inline int apple_smc_read_##type(struct apple_smc *smc, smc_key key, type *p) \ + { \ + int ret = apple_smc_read(smc, key, p, sizeof(*p)); \ + return (ret < 0) ? ret : ((ret != sizeof(*p)) ? -EINVAL : 0); \ + } \ + static inline int apple_smc_write_##type(struct apple_smc *smc, smc_key key, type p) \ + { \ + return apple_smc_write(smc, key, &p, sizeof(p)); \ + } \ + static inline int apple_smc_write_##type##_atomic(struct apple_smc *smc, smc_key key, type p) \ + { \ + return apple_smc_write_atomic(smc, key, &p, sizeof(p)); \ + } \ + static inline int apple_smc_rw_##type(struct apple_smc *smc, smc_key key, \ + type w, type *r) \ + { \ + int ret = apple_smc_rw(smc, key, &w, sizeof(w), r, sizeof(*r)); \ + return (ret < 0) ? ret : ((ret != sizeof(*r)) ? -EINVAL : 0); \ + } + +APPLE_SMC_TYPE_OPS(u64) +APPLE_SMC_TYPE_OPS(u32) +APPLE_SMC_TYPE_OPS(u16) +APPLE_SMC_TYPE_OPS(u8) +APPLE_SMC_TYPE_OPS(s64) +APPLE_SMC_TYPE_OPS(s32) +APPLE_SMC_TYPE_OPS(s16) +APPLE_SMC_TYPE_OPS(s8) + +static inline int apple_smc_read_flag(struct apple_smc *smc, smc_key key, bool *flag) +{ + u8 val; + int ret = apple_smc_read_u8(smc, key, &val); + + if (ret < 0) + return ret; + + *flag = val ? true : false; + return ret; +} + +static inline int apple_smc_write_flag(struct apple_smc *smc, smc_key key, bool state) +{ + return apple_smc_write_u8(smc, key, state ? 1 : 0); +} + +static inline int apple_smc_write_flag_atomic(struct apple_smc *smc, smc_key key, bool state) +{ + return apple_smc_write_u8_atomic(smc, key, state ? 1 : 0); +} + +#endif |