summaryrefslogtreecommitdiffstats
path: root/drivers/mfd/macsmc.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/mfd/macsmc.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/mfd/macsmc.c')
-rw-r--r--drivers/mfd/macsmc.c504
1 files changed, 504 insertions, 0 deletions
diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c
new file mode 100644
index 000000000..358feec2d
--- /dev/null
+++ b/drivers/mfd/macsmc.c
@@ -0,0 +1,504 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SMC (System Management Controller) MFD driver
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/math.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/macsmc.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/soc/apple/rtkit.h>
+#include <linux/unaligned.h>
+
+#define SMC_ENDPOINT 0x20
+
+/* We don't actually know the true size here but this seem reasonable */
+#define SMC_SHMEM_SIZE 0x1000
+#define SMC_MAX_SIZE 255
+
+#define SMC_MSG_READ_KEY 0x10
+#define SMC_MSG_WRITE_KEY 0x11
+#define SMC_MSG_GET_KEY_BY_INDEX 0x12
+#define SMC_MSG_GET_KEY_INFO 0x13
+#define SMC_MSG_INITIALIZE 0x17
+#define SMC_MSG_NOTIFICATION 0x18
+#define SMC_MSG_RW_KEY 0x20
+
+#define SMC_DATA GENMASK_ULL(63, 32)
+#define SMC_WSIZE GENMASK_ULL(31, 24)
+#define SMC_SIZE GENMASK_ULL(23, 16)
+#define SMC_ID GENMASK_ULL(15, 12)
+#define SMC_MSG GENMASK_ULL(7, 0)
+#define SMC_RESULT SMC_MSG
+
+#define SMC_TIMEOUT_MS 500
+
+static const struct mfd_cell apple_smc_devs[] = {
+ MFD_CELL_NAME("macsmc-input"),
+ MFD_CELL_NAME("macsmc-power"),
+ MFD_CELL_OF("macsmc-gpio", NULL, NULL, 0, 0, "apple,smc-gpio"),
+ MFD_CELL_OF("macsmc-hwmon", NULL, NULL, 0, 0, "apple,smc-hwmon"),
+ MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"),
+ MFD_CELL_OF("macsmc-rtc", NULL, NULL, 0, 0, "apple,smc-rtc"),
+};
+
+static int apple_smc_cmd_locked(struct apple_smc *smc, u64 cmd, u64 arg,
+ u64 size, u64 wsize, u32 *ret_data)
+{
+ u8 result;
+ int ret;
+ u64 msg;
+
+ lockdep_assert_held(&smc->mutex);
+
+ if (smc->boot_stage != APPLE_SMC_INITIALIZED)
+ return -EIO;
+ if (smc->atomic_mode)
+ return -EIO;
+
+ reinit_completion(&smc->cmd_done);
+
+ smc->msg_id = (smc->msg_id + 1) & 0xf;
+ msg = (FIELD_PREP(SMC_MSG, cmd) |
+ FIELD_PREP(SMC_SIZE, size) |
+ FIELD_PREP(SMC_WSIZE, wsize) |
+ FIELD_PREP(SMC_ID, smc->msg_id) |
+ FIELD_PREP(SMC_DATA, arg));
+
+ ret = apple_rtkit_send_message(smc->rtk, SMC_ENDPOINT, msg, NULL, false);
+ if (ret) {
+ dev_err(smc->dev, "Failed to send command\n");
+ return ret;
+ }
+
+ if (wait_for_completion_timeout(&smc->cmd_done, msecs_to_jiffies(SMC_TIMEOUT_MS)) <= 0) {
+ dev_err(smc->dev, "Command timed out (%llx)", msg);
+ return -ETIMEDOUT;
+ }
+
+ if (FIELD_GET(SMC_ID, smc->cmd_ret) != smc->msg_id) {
+ dev_err(smc->dev, "Command sequence mismatch (expected %d, got %d)\n",
+ smc->msg_id, (unsigned int)FIELD_GET(SMC_ID, smc->cmd_ret));
+ return -EIO;
+ }
+
+ result = FIELD_GET(SMC_RESULT, smc->cmd_ret);
+ if (result)
+ return -EIO;
+
+ if (ret_data)
+ *ret_data = FIELD_GET(SMC_DATA, smc->cmd_ret);
+
+ return FIELD_GET(SMC_SIZE, smc->cmd_ret);
+}
+
+static int apple_smc_cmd(struct apple_smc *smc, u64 cmd, u64 arg,
+ u64 size, u64 wsize, u32 *ret_data)
+{
+ guard(mutex)(&smc->mutex);
+
+ return apple_smc_cmd_locked(smc, cmd, arg, size, wsize, ret_data);
+}
+
+static int apple_smc_rw_locked(struct apple_smc *smc, smc_key key,
+ const void *wbuf, size_t wsize,
+ void *rbuf, size_t rsize)
+{
+ u64 smc_size, smc_wsize;
+ u32 rdata;
+ int ret;
+ u64 cmd;
+
+ lockdep_assert_held(&smc->mutex);
+
+ if (rsize > SMC_MAX_SIZE)
+ return -EINVAL;
+ if (wsize > SMC_MAX_SIZE)
+ return -EINVAL;
+
+ if (rsize && wsize) {
+ cmd = SMC_MSG_RW_KEY;
+ memcpy_toio(smc->shmem.iomem, wbuf, wsize);
+ smc_size = rsize;
+ smc_wsize = wsize;
+ } else if (wsize && !rsize) {
+ cmd = SMC_MSG_WRITE_KEY;
+ memcpy_toio(smc->shmem.iomem, wbuf, wsize);
+ /*
+ * Setting size to the length we want to write and wsize to 0
+ * looks silly but that's how the SMC protocol works ¯\_(ツ)_/¯
+ */
+ smc_size = wsize;
+ smc_wsize = 0;
+ } else if (!wsize && rsize) {
+ cmd = SMC_MSG_READ_KEY;
+ smc_size = rsize;
+ smc_wsize = 0;
+ } else {
+ return -EINVAL;
+ }
+
+ ret = apple_smc_cmd_locked(smc, cmd, key, smc_size, smc_wsize, &rdata);
+ if (ret < 0)
+ return ret;
+
+ if (rsize) {
+ /*
+ * Small data <= 4 bytes is returned as part of the reply
+ * message which is sent over the mailbox FIFO. Everything
+ * bigger has to be copied from SRAM which is mapped as
+ * Device memory.
+ */
+ if (rsize <= 4)
+ memcpy(rbuf, &rdata, rsize);
+ else
+ memcpy_fromio(rbuf, smc->shmem.iomem, rsize);
+ }
+
+ return ret;
+}
+
+int apple_smc_read(struct apple_smc *smc, smc_key key, void *buf, size_t size)
+{
+ guard(mutex)(&smc->mutex);
+
+ return apple_smc_rw_locked(smc, key, NULL, 0, buf, size);
+}
+EXPORT_SYMBOL(apple_smc_read);
+
+int apple_smc_write(struct apple_smc *smc, smc_key key, const void *buf, size_t size)
+{
+ guard(mutex)(&smc->mutex);
+
+ return apple_smc_rw_locked(smc, key, buf, size, NULL, 0);
+}
+EXPORT_SYMBOL(apple_smc_write);
+
+int apple_smc_rw(struct apple_smc *smc, smc_key key, const void *wbuf, size_t wsize,
+ void *rbuf, size_t rsize)
+{
+ guard(mutex)(&smc->mutex);
+
+ return apple_smc_rw_locked(smc, key, wbuf, wsize, rbuf, rsize);
+}
+EXPORT_SYMBOL(apple_smc_rw);
+
+int apple_smc_get_key_by_index(struct apple_smc *smc, int index, smc_key *key)
+{
+ int ret;
+
+ ret = apple_smc_cmd(smc, SMC_MSG_GET_KEY_BY_INDEX, index, 0, 0, key);
+
+ *key = swab32(*key);
+ return ret;
+}
+EXPORT_SYMBOL(apple_smc_get_key_by_index);
+
+int apple_smc_get_key_info(struct apple_smc *smc, smc_key key, struct apple_smc_key_info *info)
+{
+ u8 key_info[6];
+ int ret;
+
+ ret = apple_smc_cmd(smc, SMC_MSG_GET_KEY_INFO, key, 0, 0, NULL);
+ if (ret >= 0 && info) {
+ memcpy_fromio(key_info, smc->shmem.iomem, sizeof(key_info));
+ info->size = key_info[0];
+ info->type_code = get_unaligned_be32(&key_info[1]);
+ info->flags = key_info[5];
+ }
+ return ret;
+}
+EXPORT_SYMBOL(apple_smc_get_key_info);
+
+int apple_smc_enter_atomic(struct apple_smc *smc)
+{
+ guard(mutex)(&smc->mutex);
+
+ /*
+ * Disable notifications since this is called before shutdown and no
+ * notification handler will be able to handle the notification
+ * using atomic operations only. Also ignore any failure here
+ * because we're about to shut down or reboot anyway.
+ * We can't use apple_smc_write_flag here since that would try to lock
+ * smc->mutex again.
+ */
+ const u8 flag = 0;
+
+ apple_smc_rw_locked(smc, SMC_KEY(NTAP), &flag, sizeof(flag), NULL, 0);
+
+ smc->atomic_mode = true;
+
+ return 0;
+}
+EXPORT_SYMBOL(apple_smc_enter_atomic);
+
+int apple_smc_write_atomic(struct apple_smc *smc, smc_key key, const void *buf, size_t size)
+{
+ guard(spinlock_irqsave)(&smc->lock);
+ u8 result;
+ int ret;
+ u64 msg;
+
+ if (size > SMC_MAX_SIZE || size == 0)
+ return -EINVAL;
+
+ if (smc->boot_stage != APPLE_SMC_INITIALIZED)
+ return -EIO;
+ if (!smc->atomic_mode)
+ return -EIO;
+
+ memcpy_toio(smc->shmem.iomem, buf, size);
+ smc->msg_id = (smc->msg_id + 1) & 0xf;
+ msg = (FIELD_PREP(SMC_MSG, SMC_MSG_WRITE_KEY) |
+ FIELD_PREP(SMC_SIZE, size) |
+ FIELD_PREP(SMC_ID, smc->msg_id) |
+ FIELD_PREP(SMC_DATA, key));
+ smc->atomic_pending = true;
+
+ ret = apple_rtkit_send_message(smc->rtk, SMC_ENDPOINT, msg, NULL, true);
+ if (ret < 0) {
+ dev_err(smc->dev, "Failed to send command (%d)\n", ret);
+ return ret;
+ }
+
+ while (smc->atomic_pending) {
+ ret = apple_rtkit_poll(smc->rtk);
+ if (ret < 0) {
+ dev_err(smc->dev, "RTKit poll failed (%llx)", msg);
+ return ret;
+ }
+ udelay(100);
+ }
+
+ if (FIELD_GET(SMC_ID, smc->cmd_ret) != smc->msg_id) {
+ dev_err(smc->dev, "Command sequence mismatch (expected %d, got %d)\n",
+ smc->msg_id, (unsigned int)FIELD_GET(SMC_ID, smc->cmd_ret));
+ return -EIO;
+ }
+
+ result = FIELD_GET(SMC_RESULT, smc->cmd_ret);
+ if (result)
+ return -EIO;
+
+ return FIELD_GET(SMC_SIZE, smc->cmd_ret);
+}
+EXPORT_SYMBOL(apple_smc_write_atomic);
+
+static void apple_smc_rtkit_crashed(void *cookie, const void *bfr, size_t bfr_len)
+{
+ struct apple_smc *smc = cookie;
+
+ smc->boot_stage = APPLE_SMC_ERROR_CRASHED;
+ dev_err(smc->dev, "SMC crashed! Your system will reboot in a few seconds...\n");
+}
+
+static int apple_smc_rtkit_shmem_setup(void *cookie, struct apple_rtkit_shmem *bfr)
+{
+ struct apple_smc *smc = cookie;
+ size_t bfr_end;
+
+ if (!bfr->iova) {
+ dev_err(smc->dev, "RTKit wants a RAM buffer\n");
+ return -EIO;
+ }
+
+ if (check_add_overflow(bfr->iova, bfr->size - 1, &bfr_end))
+ return -EFAULT;
+
+ if (bfr->iova < smc->sram->start || bfr->iova > smc->sram->end ||
+ bfr_end > smc->sram->end) {
+ dev_err(smc->dev, "RTKit buffer request outside SRAM region: [0x%llx, 0x%llx]\n",
+ (unsigned long long)bfr->iova,
+ (unsigned long long)bfr_end);
+ return -EFAULT;
+ }
+
+ bfr->iomem = smc->sram_base + (bfr->iova - smc->sram->start);
+ bfr->is_mapped = true;
+
+ return 0;
+}
+
+static bool apple_smc_rtkit_recv_early(void *cookie, u8 endpoint, u64 message)
+{
+ struct apple_smc *smc = cookie;
+
+ if (endpoint != SMC_ENDPOINT) {
+ dev_warn(smc->dev, "Received message for unknown endpoint 0x%x\n", endpoint);
+ return false;
+ }
+
+ if (smc->boot_stage == APPLE_SMC_BOOTING) {
+ int ret;
+
+ smc->shmem.iova = message;
+ smc->shmem.size = SMC_SHMEM_SIZE;
+ ret = apple_smc_rtkit_shmem_setup(smc, &smc->shmem);
+ if (ret < 0) {
+ smc->boot_stage = APPLE_SMC_ERROR_NO_SHMEM;
+ dev_err(smc->dev, "Failed to initialize shared memory (%d)\n", ret);
+ } else {
+ smc->boot_stage = APPLE_SMC_INITIALIZED;
+ }
+ complete(&smc->init_done);
+ } else if (FIELD_GET(SMC_MSG, message) == SMC_MSG_NOTIFICATION) {
+ /* Handle these in the RTKit worker thread */
+ return false;
+ } else {
+ smc->cmd_ret = message;
+ if (smc->atomic_pending)
+ smc->atomic_pending = false;
+ else
+ complete(&smc->cmd_done);
+ }
+
+ return true;
+}
+
+static void apple_smc_rtkit_recv(void *cookie, u8 endpoint, u64 message)
+{
+ struct apple_smc *smc = cookie;
+
+ if (endpoint != SMC_ENDPOINT) {
+ dev_warn(smc->dev, "Received message for unknown endpoint 0x%x\n", endpoint);
+ return;
+ }
+
+ if (FIELD_GET(SMC_MSG, message) != SMC_MSG_NOTIFICATION) {
+ dev_warn(smc->dev, "Received unknown message from worker: 0x%llx\n", message);
+ return;
+ }
+
+ blocking_notifier_call_chain(&smc->event_handlers, FIELD_GET(SMC_DATA, message), NULL);
+}
+
+static const struct apple_rtkit_ops apple_smc_rtkit_ops = {
+ .crashed = apple_smc_rtkit_crashed,
+ .recv_message = apple_smc_rtkit_recv,
+ .recv_message_early = apple_smc_rtkit_recv_early,
+ .shmem_setup = apple_smc_rtkit_shmem_setup,
+};
+
+static void apple_smc_rtkit_shutdown(void *data)
+{
+ struct apple_smc *smc = data;
+
+ /* Shut down SMC firmware, if it's not completely wedged */
+ if (apple_rtkit_is_running(smc->rtk))
+ apple_rtkit_quiesce(smc->rtk);
+}
+
+static void apple_smc_disable_notifications(void *data)
+{
+ struct apple_smc *smc = data;
+
+ apple_smc_write_flag(smc, SMC_KEY(NTAP), false);
+}
+
+static int apple_smc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct apple_smc *smc;
+ u32 count;
+ int ret;
+
+ smc = devm_kzalloc(dev, sizeof(*smc), GFP_KERNEL);
+ if (!smc)
+ return -ENOMEM;
+
+ mutex_init(&smc->mutex);
+ smc->dev = &pdev->dev;
+ smc->sram_base = devm_platform_get_and_ioremap_resource(pdev, 1, &smc->sram);
+ if (IS_ERR(smc->sram_base))
+ return dev_err_probe(dev, PTR_ERR(smc->sram_base), "Failed to map SRAM region");
+
+ smc->rtk = devm_apple_rtkit_init(dev, smc, NULL, 0, &apple_smc_rtkit_ops);
+ if (IS_ERR(smc->rtk))
+ return dev_err_probe(dev, PTR_ERR(smc->rtk), "Failed to initialize RTKit");
+
+ smc->boot_stage = APPLE_SMC_BOOTING;
+ ret = apple_rtkit_wake(smc->rtk);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to wake up SMC");
+
+ ret = devm_add_action_or_reset(dev, apple_smc_rtkit_shutdown, smc);
+ if (ret)
+ return ret;
+
+ ret = apple_rtkit_start_ep(smc->rtk, SMC_ENDPOINT);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to start SMC endpoint");
+
+ init_completion(&smc->init_done);
+ init_completion(&smc->cmd_done);
+
+ ret = apple_rtkit_send_message(smc->rtk, SMC_ENDPOINT,
+ FIELD_PREP(SMC_MSG, SMC_MSG_INITIALIZE), NULL, false);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to send init message");
+
+ if (wait_for_completion_timeout(&smc->init_done, msecs_to_jiffies(SMC_TIMEOUT_MS)) == 0) {
+ dev_err(dev, "Timed out initializing SMC");
+ return -ETIMEDOUT;
+ }
+
+ if (smc->boot_stage != APPLE_SMC_INITIALIZED) {
+ dev_err(dev, "SMC failed to boot successfully, boot stage=%d\n", smc->boot_stage);
+ return -EIO;
+ }
+
+ dev_set_drvdata(&pdev->dev, smc);
+ BLOCKING_INIT_NOTIFIER_HEAD(&smc->event_handlers);
+
+ ret = apple_smc_read_u32(smc, SMC_KEY(#KEY), &count);
+ if (ret)
+ return dev_err_probe(smc->dev, ret, "Failed to get key count");
+ smc->key_count = be32_to_cpu(count);
+
+ /* Enable notifications */
+ apple_smc_write_flag(smc, SMC_KEY(NTAP), true);
+ ret = devm_add_action_or_reset(dev, apple_smc_disable_notifications, smc);
+ if (ret)
+ return ret;
+
+ ret = devm_mfd_add_devices(smc->dev, PLATFORM_DEVID_NONE,
+ apple_smc_devs, ARRAY_SIZE(apple_smc_devs),
+ NULL, 0, NULL);
+ if (ret)
+ return dev_err_probe(smc->dev, ret, "Failed to register sub-devices");
+
+
+ return 0;
+}
+
+static const struct of_device_id apple_smc_of_match[] = {
+ { .compatible = "apple,t8103-smc" },
+ { .compatible = "apple,smc" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, apple_smc_of_match);
+
+static struct platform_driver apple_smc_driver = {
+ .driver = {
+ .name = "macsmc",
+ .of_match_table = apple_smc_of_match,
+ },
+ .probe = apple_smc_probe,
+};
+module_platform_driver(apple_smc_driver);
+
+MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");
+MODULE_AUTHOR("Sven Peter <sven@kernel.org>");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_DESCRIPTION("Apple SMC driver");