Add a backend that talks to the SMC on Intel Macs over ACPI. It supports the old I/O port interface, and also MMIO and interrupt-driven completion, which applesmc doesn't have. If an interrupt is missed it falls back to polling.
This is the base that lets the macsmc drivers replace applesmc. Signed-off-by: Atharva Tiwari <[email protected]> --- drivers/platform/x86/Kconfig | 10 + drivers/platform/x86/Makefile | 1 + drivers/platform/x86/macsmc-acpi.c | 642 +++++++++++++++++++++++++++++ 3 files changed, 653 insertions(+) create mode 100644 drivers/platform/x86/macsmc-acpi.c diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 4851bf451..448aa2db6 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -202,6 +202,16 @@ config ADV_SWBUTTON To compile this driver as a module, choose M here. The module will be called adv_swbutton. +config MACSMC_ACPI + tristate "Apple SMC (System Management Controller) ACPI Backend" + depends on MFD_MACSMC_CORE && ACPI && !SENSORS_APPLESMC + help + This driver allows communication with the SMC (System Management Controller) + on Intel-Macs. It is used to control fans, control battery, and more. + + To compile this driver as a module, choose M here. The module will + be called macsmc_acpi. + config APPLE_GMUX tristate "Apple Gmux Driver" depends on ACPI && PCI diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index cab20a414..933aed4a8 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -28,6 +28,7 @@ obj-y += amd/ obj-$(CONFIG_ADV_SWBUTTON) += adv_swbutton.o # Apple +obj-$(CONFIG_MACSMC_ACPI) += macsmc-acpi.o obj-$(CONFIG_APPLE_GMUX) += apple-gmux.o # ASUS diff --git a/drivers/platform/x86/macsmc-acpi.c b/drivers/platform/x86/macsmc-acpi.c new file mode 100644 index 000000000..a06ec921a --- /dev/null +++ b/drivers/platform/x86/macsmc-acpi.c @@ -0,0 +1,642 @@ +// SPDX-License-Identifier: GPL-2.0-only OR MIT +/* + * Apple SMC ACPI backend + * Copyright (C) 2026 Atharva Tiwari <[email protected]> + * + * PIO code taken from drivers/hwmon/applesmc.c: + * Copyright (C) 2007 Nicolas Boichat <[email protected]> + * Copyright (C) 2010 Henrik Rydberg <[email protected]> + */ + +#include <linux/acpi.h> +#include <linux/byteorder/generic.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kfifo.h> +#include <linux/mfd/macsmc.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/spinlock.h> +#include <linux/unaligned.h> +#include <linux/workqueue.h> + +#define SMC_IO_DATA_PORT 0 +#define SMC_IO_CMD_PORT 4 +#define SMC_IO_NR_PORTS 32 + +#define SMC_IO_STATUS_AWAITING_DATA BIT(0) +#define SMC_IO_STATUS_IB_CLOSED BIT(1) +#define SMC_IO_STATUS_BUSY BIT(2) + +#define SMC_MMIO_KEY_DATA 0 +#define SMC_MMIO_KEY_INTERRUPT_STATUS 0x4000 +#define SMC_MMIO_KEY_STATUS 0x4005 +#define SMC_MMIO_KEY_NAME 0x78 +#define SMC_MMIO_KEY_DATA_LEN 0x7D +#define SMC_MMIO_KEY_SMC_ID 0x7E +#define SMC_MMIO_KEY_CMD 0x7F +#define SMC_MMIO_MIN_SIZE 0x4006 + +#define SMC_TIMEOUT_MS 1000 + +struct apple_smc_acpi { + struct device *dev; + + u8 __iomem *iomem_base; + u32 iomem_base_addr, iomem_base_size; + bool is_mmio; + + u16 port_base; + bool has_port; + + bool has_interrupt; + bool interrupt_enabled; + struct completion cmd_done; + + struct blocking_notifier_head event_handlers; + struct work_struct shutdown_work; + struct work_struct notifier_work; + + DECLARE_KFIFO(event_fifo, u8, 64); + spinlock_t event_lock; +}; + + +static int apple_smc_acpi_port_wait(struct apple_smc_acpi *smc, u8 val, u8 mask) +{ + int ms; + + for (ms = SMC_TIMEOUT_MS; ms != 0; ms--) { + if ((inb(smc->port_base + SMC_IO_CMD_PORT) & mask) == val) + return 0; + + fsleep(1000); + } + dev_dbg(smc->dev, "port/wait: timeout value:%u, mask:%u\n", val, mask); + return -ETIMEDOUT; +} + +static int apple_smc_acpi_port_write_byte(struct apple_smc_acpi *smc, u8 buf) +{ + int ret; + + ret = apple_smc_acpi_port_wait(smc, 0, SMC_IO_STATUS_IB_CLOSED) ? : + apple_smc_acpi_port_wait(smc, SMC_IO_STATUS_BUSY, SMC_IO_STATUS_BUSY); + if (ret) + return ret; + + outb(buf, smc->port_base + SMC_IO_DATA_PORT); + return 0; +} + +static int apple_smc_acpi_port_write_cmd(struct apple_smc_acpi *smc, u8 buf) +{ + int ret; + + ret = apple_smc_acpi_port_wait(smc, 0, SMC_IO_STATUS_IB_CLOSED); + if (ret) + return ret; + + outb(buf, smc->port_base + SMC_IO_CMD_PORT); + return 0; +} + +static int apple_smc_acpi_port_write_key(struct apple_smc_acpi *smc, smc_key key) +{ + int i; + + for (i = 3; i >= 0; i--) { + if (apple_smc_acpi_port_write_byte(smc, (u8)(key >> (i * 8)))) + return -EIO; + } + return 0; +} + +static int apple_smc_acpi_port_valid(struct apple_smc_acpi *smc) +{ + int ret; + + ret = apple_smc_acpi_port_wait(smc, 0, SMC_IO_STATUS_BUSY); + if (!ret) + return ret; + + ret = apple_smc_acpi_port_write_cmd(smc, SMC_MSG_READ_KEY); + if (ret) + return ret; + + return apple_smc_acpi_port_wait(smc, 0, SMC_IO_STATUS_BUSY); +} + +static int apple_smc_acpi_port_read(struct apple_smc_acpi *smc, u8 cmd, smc_key key, + void *buffer, size_t len) +{ + int ret; + + ret = apple_smc_acpi_port_valid(smc); + if (ret) + return ret; + + if (apple_smc_acpi_port_write_cmd(smc, cmd) || apple_smc_acpi_port_write_key(smc, key)) { + dev_dbg(smc->dev, "port/read: read argument failed, key: 0x%X, cmd: 0x%X\n", + key, cmd); + return -EIO; + } + + if (apple_smc_acpi_port_write_byte(smc, len)) { + dev_dbg(smc->dev, "port/read: read len failed, key: 0x%X, len: 0x%lX\n", key, len); + return -EIO; + } + + for (ret = 0; ret < len; ret++) { + if (apple_smc_acpi_port_wait(smc, + SMC_IO_STATUS_AWAITING_DATA | SMC_IO_STATUS_BUSY, + SMC_IO_STATUS_AWAITING_DATA | SMC_IO_STATUS_BUSY)) { + dev_dbg(smc->dev, "port/read: read failed, key: 0x%X\n", key); + return -EIO; + } + ((u8 *)buffer)[ret] = inb(smc->port_base + SMC_IO_DATA_PORT); + } + + return apple_smc_acpi_port_wait(smc, 0, SMC_IO_STATUS_BUSY); +} + +static int apple_smc_acpi_port_write(struct apple_smc_acpi *smc, smc_key key, const void *buffer, + size_t len) +{ + int ret; + + ret = apple_smc_acpi_port_valid(smc); + if (ret) + return ret; + + if (apple_smc_acpi_port_write_cmd(smc, SMC_MSG_WRITE_KEY) || + apple_smc_acpi_port_write_key(smc, key)) { + dev_dbg(smc->dev, "port/write: write argument failed, key: 0x%X\n", key); + return -EIO; + } + + if (apple_smc_acpi_port_write_byte(smc, len)) { + dev_dbg(smc->dev, "port/write: write len failed, key: 0x%X, len: 0x%lX\n", + key, len); + return -EIO; + } + + for (ret = 0; ret < len; ret++) { + if (apple_smc_acpi_port_write_byte(smc, ((const u8 *)buffer)[ret])) { + dev_dbg(smc->dev, "port/write: write failed, key: 0x%X\n", key); + return -EIO; + } + } + return apple_smc_acpi_port_wait(smc, 0, SMC_IO_STATUS_BUSY); +} + +static int apple_smc_acpi_port_get_key_info(struct apple_smc_acpi *smc, + smc_key key, struct apple_smc_key_info *info) +{ + u8 buf[6]; + + if (apple_smc_acpi_port_read(smc, SMC_MSG_GET_KEY_INFO, key, buf, 6)) + return -EIO; + + if (!info) + return 0; + + info->size = buf[0]; + info->type_code = get_unaligned_be32(&buf[1]); + info->flags = buf[5]; + + return 0; +} + +static void apple_smc_acpi_mmio_clear(struct apple_smc_acpi *smc) +{ + if (ioread8(smc->iomem_base + SMC_MMIO_KEY_STATUS)) + return iowrite8(0, smc->iomem_base + SMC_MMIO_KEY_STATUS); +} + +static int apple_smc_acpi_mmio_wait(struct apple_smc_acpi *smc) +{ + int ms = SMC_TIMEOUT_MS; + + if (smc->interrupt_enabled) { + if (wait_for_completion_timeout(&smc->cmd_done, + msecs_to_jiffies(SMC_TIMEOUT_MS)) > 0) + return 0; + + smc->interrupt_enabled = 0; + dev_dbg(smc->dev, "mmio/wait: interrupt missed, reverting to polling\n"); + } + + for (ms = SMC_TIMEOUT_MS; ms != 0; ms--) { + if (ioread8(smc->iomem_base + SMC_MMIO_KEY_STATUS) & 0x20) + return 0; + + fsleep(1000); + } + dev_dbg(smc->dev, "mmio/wait: timeout"); + return -ETIMEDOUT; +} + +static int apple_smc_acpi_mmio_read(struct apple_smc_acpi *smc, u8 cmd, smc_key key, + void *buffer, size_t len) +{ + u8 ret; + + reinit_completion(&smc->cmd_done); + apple_smc_acpi_mmio_clear(smc); + iowrite32be(key, smc->iomem_base + SMC_MMIO_KEY_NAME); + iowrite8(0, smc->iomem_base + SMC_MMIO_KEY_SMC_ID); + iowrite8(cmd, smc->iomem_base + SMC_MMIO_KEY_CMD); + + if (apple_smc_acpi_mmio_wait(smc)) + return -EIO; + + ret = ioread8(smc->iomem_base + SMC_MMIO_KEY_CMD); + if (ret) { + dev_dbg(smc->dev, "mmio/read: read failed, ret: 0x%X, key: 0x%X\n", ret, key); + return -ret; + } + + memcpy_fromio(buffer, smc->iomem_base + SMC_MMIO_KEY_DATA, len); + return 0; +} + +static int apple_smc_acpi_mmio_write(struct apple_smc_acpi *smc, smc_key key, const void *buffer, + size_t len) +{ + u8 ret; + + reinit_completion(&smc->cmd_done); + apple_smc_acpi_mmio_clear(smc); + iowrite32be(key, smc->iomem_base + SMC_MMIO_KEY_NAME); + memcpy_toio(smc->iomem_base + SMC_MMIO_KEY_DATA, buffer, len); + iowrite8(len, smc->iomem_base + SMC_MMIO_KEY_DATA_LEN); + iowrite8(0, smc->iomem_base + SMC_MMIO_KEY_SMC_ID); + iowrite8(SMC_MSG_WRITE_KEY, smc->iomem_base + SMC_MMIO_KEY_CMD); + + if (apple_smc_acpi_mmio_wait(smc)) + return -EIO; + + ret = ioread8(smc->iomem_base + SMC_MMIO_KEY_CMD); + if (ret) { + dev_dbg(smc->dev, "mmio/write: write failed, ret: 0x%X, key: 0x%X\n", ret, key); + return -ret; + } + + return 0; +} + +static int apple_smc_acpi_mmio_get_key_info(struct apple_smc_acpi *smc, smc_key key, + struct apple_smc_key_info *info) +{ + u8 ret; + + reinit_completion(&smc->cmd_done); + apple_smc_acpi_mmio_clear(smc); + iowrite32be(key, smc->iomem_base + SMC_MMIO_KEY_NAME); + iowrite8(0, smc->iomem_base + SMC_MMIO_KEY_SMC_ID); + iowrite8(SMC_MSG_GET_KEY_INFO, smc->iomem_base + SMC_MMIO_KEY_CMD); + + if (apple_smc_acpi_mmio_wait(smc)) + return -EIO; + + ret = ioread8(smc->iomem_base + SMC_MMIO_KEY_CMD); + if (ret) { + dev_dbg(smc->dev, "mmio/get_key_info failed, ret: 0x%X, key: 0x%X\n", ret, key); + return -ret; + } + + + if (!info) + return 0; + info->type_code = cpu_to_be32(ioread32(smc->iomem_base + SMC_MMIO_KEY_DATA)); + info->size = ioread8(smc->iomem_base + 5); + info->flags = ioread8(smc->iomem_base + 6); + + return 0; +} + +static void apple_smc_acpi_shutdown_work(struct work_struct *work) +{ + orderly_poweroff(true); +} + +static void apple_smc_acpi_notifier_work(struct work_struct *work) +{ + struct apple_smc_acpi *smc = + container_of(work, struct apple_smc_acpi, notifier_work); + + unsigned long flags; + uint8_t event; + + for (;;) { + spin_lock_irqsave(&smc->event_lock, flags); + + if (!kfifo_get(&smc->event_fifo, &event)) { + spin_unlock_irqrestore(&smc->event_lock, flags); + break; + } + spin_unlock_irqrestore(&smc->event_lock, flags); + + blocking_notifier_call_chain(&smc->event_handlers, event, NULL); + } +} + +static irqreturn_t apple_smc_acpi_irq(int irq, void *data) +{ + struct apple_smc_acpi *smc = data; + uint8_t status = 0, int_id = 0; + unsigned long flags; + + if (smc->is_mmio) { + status = ioread8(smc->iomem_base + SMC_MMIO_KEY_INTERRUPT_STATUS); + if ((status & 0x20) == 0 && status != 0) + return IRQ_HANDLED; + } else { + status = inb(smc->port_base + SMC_IO_CMD_PORT); + if ((status & 0x40) == 0 && status != 0) + return IRQ_HANDLED; + } + + int_id = inb(smc->port_base + 0x1F); + switch (int_id) { + case 0x4B: // SMC Command done + complete(&smc->cmd_done); + break; + case 0x40: // Shutdown Imminet + schedule_work(&smc->shutdown_work); + break; + case 0x41: // bridgeOS Crash + dev_crit(smc->dev, "BridgeOS Crashed!!!\n"); + break; + case 0x2A: // ALS Change + case 0x54: // Thermal Level Changed + case 0x55: // PlatformFuntion + case 0x60: // SMS Drop + case 0x69: // SMS Orientation + case 0x6F: // SMS Shock + case 0x80: // PLimit Changed + spin_lock_irqsave(&smc->event_lock, flags); + if (!kfifo_put(&smc->event_fifo, int_id)) + dev_warn_ratelimited(smc->dev, "Notification lost: %u\n", int_id); + + spin_unlock_irqrestore(&smc->event_lock, flags); + + schedule_work(&smc->notifier_work); + break; + } + + return IRQ_HANDLED; +} + +static acpi_status apple_smc_acpi_walk_resources(struct acpi_resource *res, + void *data) +{ + struct apple_smc_acpi *smc = data; + int ret = 0; + + switch (res->type) { + case ACPI_RESOURCE_TYPE_IO: + if (!smc->has_port) { + if (res->data.io.address_length < SMC_IO_NR_PORTS) + return AE_ERROR; + smc->port_base = res->data.io.minimum; + smc->has_port = true; + } + return AE_OK; + + case ACPI_RESOURCE_TYPE_FIXED_MEMORY32: + if (!smc->is_mmio) { + if (res->data.fixed_memory32.address_length < SMC_MMIO_MIN_SIZE) { + dev_dbg(smc->dev, "found mmio support but its too small: %u\n", + res->data.fixed_memory32.address_length); + return AE_OK; + } + smc->iomem_base_addr = res->data.fixed_memory32.address; + smc->iomem_base_size = res->data.fixed_memory32.address_length; + smc->is_mmio = true; + } + return AE_OK; + + case ACPI_RESOURCE_TYPE_IRQ: + ret = devm_request_irq(smc->dev, res->data.irq.interrupts[0], + apple_smc_acpi_irq, + 0, "macsmc-acpi", smc); + if (ret < 0) { + dev_dbg(smc->dev, "Unable to register interrupts\n"); + smc->has_interrupt = false; + return AE_OK; + } + smc->has_interrupt = true; + return AE_OK; + + case ACPI_RESOURCE_TYPE_END_TAG: + if (smc->has_port) + return AE_OK; + else + return AE_NOT_FOUND; + + default: + return AE_OK; + } +} + +static void apple_smc_acpi_try_enable_mmio(struct apple_smc_acpi *smc) +{ + if (!smc->is_mmio) + return; + + u8 ldkn; + + smc->iomem_base = ioremap(smc->iomem_base_addr, smc->iomem_base_size); + if (!smc->iomem_base) + goto out; + + if (ioread8(smc->iomem_base + SMC_MMIO_KEY_STATUS) == 0xFF) { + dev_dbg(smc->dev, "mmio enable failed: init status is 0xff\n"); + goto out_iomem; + } + + if (apple_smc_acpi_mmio_read(smc, SMC_MSG_READ_KEY, SMC_KEY(LDKN), &ldkn, 1)) { + dev_dbg(smc->dev, "mmio enable failed: ldkn read failed\n"); + goto out_iomem; + } + + if (ldkn < 2) { + dev_dbg(smc->dev, "mmio enable failed: ldkn version less than 2\n"); + goto out_iomem; + } + return; + +out_iomem: + iounmap(smc->iomem_base); +out: + smc->is_mmio = false; +} + +static void apple_smc_acpi_try_enable_interrupts(struct apple_smc_acpi *smc) +{ + if (!smc->has_interrupt) + return; + + const u8 enable = 1; + int ret; + + if (smc->is_mmio) + ret = apple_smc_acpi_mmio_write(smc, SMC_KEY(NTOK), &enable, 1); + else + ret = apple_smc_acpi_port_write(smc, SMC_KEY(NTOK), &enable, 1); + + if (ret < 0) { + dev_dbg(smc->dev, "Unable to enable interrupts\n"); + smc->interrupt_enabled = 0; + return; + } + + smc->interrupt_enabled = 1; +} + +static int apple_smc_acpi_read(void *cookie, smc_key key, void *buf, size_t size) +{ + struct apple_smc_acpi *smc = cookie; + int ret; + + if (smc->is_mmio) + ret = apple_smc_acpi_mmio_read(smc, SMC_MSG_READ_KEY, + key, buf, size); + else + ret = apple_smc_acpi_port_read(smc, SMC_MSG_READ_KEY, + key, buf, size); + + if (ret < 0) + return ret; + + return size; + +} + +static int apple_smc_acpi_write(void *cookie, smc_key key, const void *buf, size_t size) +{ + struct apple_smc_acpi *smc = cookie; + int ret; + + if (smc->is_mmio) + ret = apple_smc_acpi_mmio_write(smc, key, buf, size); + else + ret = apple_smc_acpi_port_write(smc, key, buf, size); + + if (ret < 0) + return ret; + + return size; +} + +static int apple_smc_acpi_get_key_by_index(void *cookie, int index, smc_key *key) +{ + struct apple_smc_acpi *smc = cookie; + + if (smc->is_mmio) + return apple_smc_acpi_mmio_read(smc, SMC_MSG_GET_KEY_BY_INDEX, (smc_key) index, + key, 4); + else + return apple_smc_acpi_port_read(smc, SMC_MSG_GET_KEY_BY_INDEX, (smc_key) index, + key, 4); + +} + +static int apple_smc_acpi_get_key_info(void *cookie, smc_key key, + struct apple_smc_key_info *info) +{ + struct apple_smc_acpi *smc = cookie; + + if (smc->is_mmio) + return apple_smc_acpi_mmio_get_key_info(smc, key, info); + else + return apple_smc_acpi_port_get_key_info(smc, key, info); + +} + +static void apple_smc_acpi_notifications(void *cookie) +{ + const u8 buf = 0; + + apple_smc_acpi_write(cookie, SMC_KEY(NTOK), &buf, 1); +} + +static const struct apple_smc_backend_ops apple_smc_acpi_be_ops = { + .read = apple_smc_acpi_read, + .write = apple_smc_acpi_write, + .get_key_by_index = apple_smc_acpi_get_key_by_index, + .get_key_info = apple_smc_acpi_get_key_info, + .disable_notifications = apple_smc_acpi_notifications, +}; + +static int apple_smc_acpi_probe(struct platform_device *pdev) +{ + struct acpi_device *adev = ACPI_COMPANION(&pdev->dev); + struct apple_smc_acpi *smc; + acpi_status status; + + smc = devm_kzalloc(&pdev->dev, sizeof(*smc), GFP_KERNEL); + if (!smc) + return -ENOMEM; + + smc->dev = &pdev->dev; + init_completion(&smc->cmd_done); + status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS, + apple_smc_acpi_walk_resources, smc); + + if (ACPI_FAILURE(status)) + return -ENODEV; + + apple_smc_acpi_try_enable_mmio(smc); + BLOCKING_INIT_NOTIFIER_HEAD(&smc->event_handlers); + INIT_WORK(&smc->shutdown_work, apple_smc_acpi_shutdown_work); + INIT_WORK(&smc->notifier_work, apple_smc_acpi_notifier_work); + spin_lock_init(&smc->event_lock); + INIT_KFIFO(smc->event_fifo); + apple_smc_acpi_try_enable_interrupts(smc); + + return apple_smc_probe(smc->dev, &apple_smc_acpi_be_ops, smc, &smc->event_handlers, true); +} + +static int apple_smc_acpi_resume(struct device *dev) +{ + struct apple_smc *smc = dev_get_drvdata(dev); + struct apple_smc_acpi *smc_acpi = smc->be_cookie; + + /* NTOK may be set to 0 on resume */ + if (smc_acpi->interrupt_enabled) { + smc_acpi->interrupt_enabled = 0; + apple_smc_acpi_try_enable_interrupts(smc_acpi); + } + return 0; +} + +static const struct dev_pm_ops apple_smc_acpi_ops = { + .resume = apple_smc_acpi_resume, +}; + +static const struct acpi_device_id apple_smc_acpi_ids[] = { + {"APP0001", 0}, + {"", 0}, +}; +MODULE_DEVICE_TABLE(acpi, apple_smc_acpi_ids); + +static struct platform_driver apple_smc_acpi_driver = { + .probe = apple_smc_acpi_probe, + .driver = { + .name = "macsmc-acpi", + .acpi_match_table = apple_smc_acpi_ids, + .pm = &apple_smc_acpi_ops, + }, +}; +module_platform_driver(apple_smc_acpi_driver); + +MODULE_AUTHOR("Atharva Tiwari <[email protected]>"); +MODULE_LICENSE("Dual MIT/GPL"); +MODULE_DESCRIPTION("Apple SMC ACPI backend"); +MODULE_DEVICE_TABLE(acpi, apple_smc_acpi_ids); -- 2.55.0
