From patchwork Sat May 3 10:06:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sven Peter via B4 Relay X-Patchwork-Id: 887043 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 468381A8F98; Sat, 3 May 2025 10:07:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746266836; cv=none; b=YqSxvCFnqd2+Ub85B3y8JpOtMQ6wjhGNjFCByhZVwYkiyMZiJyzN4MKbYSkjSmT1fqLBz79QDncriOO+cx7f6MmRuXNRC9iAPjwJk+enZrqqN7NrHVPpr3o6CNqrPT6rv+SNZ3SIxBDfxoH3/w1czXkAn2vBFeAUGHefTkEuZn8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746266836; c=relaxed/simple; bh=IZZepndq9u3n5xTpWe8MNY+9d1m5AndO2txnnZ9f+Vk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Az7coMRkOuOXLS5R4sW4i0b+F+od/jN7ykmD5VRBlcgyPCv1YG0pqyQ9YUSnP4YzaQmiLdJqmQIq5/Pyv60YfWdLqygjU29FbHSF+ZVYTVQmDq/l7fxe1NhEryECBsoK8xitInwtxDS3fw+/RG/iwt9BsZ4sjV0QB3srp+w2cMM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YhkS1YBW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YhkS1YBW" Received: by smtp.kernel.org (Postfix) with ESMTPS id DD737C4CEF6; Sat, 3 May 2025 10:07:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746266836; bh=IZZepndq9u3n5xTpWe8MNY+9d1m5AndO2txnnZ9f+Vk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=YhkS1YBWD3fKNym/gpS2H2V7f8TpkDqsXDOobK7GIZCkckwrXTzzDlI2fSsgGOlQ4 U0YnWGh06w5RbtMon3kdDe58zWX7SLk4dn9hAp8FaV1ZebVhX2DdQdrId89zbOuJ+3 7IkwGbSNs9oihOd5lvAxpksLywN8iqBRXnJh5PpPoAQDrc6pNwVc/Rq20JCwJult/I yJixftRAICkvgP2oUk5SY6virJ5dWzzJ+GVYJemgJVa0rWOOkNwktsDjFA7OuZ6ndh iJQ+IAImouSXh8DdxX2dsg/lyYpowRJWaEshj2I/vm3Rm0W7hYXWAXfzZe6rgOpFy7 9mhDLYhNJMmYg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5034C369D9; Sat, 3 May 2025 10:07:15 +0000 (UTC) From: Sven Peter via B4 Relay Date: Sat, 03 May 2025 10:06:51 +0000 Subject: [PATCH v4 4/9] mfd: Add Apple Silicon System Management Controller Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250503-smc-6-15-v4-4-500b9b6546fc@svenpeter.dev> References: <20250503-smc-6-15-v4-0-500b9b6546fc@svenpeter.dev> In-Reply-To: <20250503-smc-6-15-v4-0-500b9b6546fc@svenpeter.dev> To: Sven Peter , Janne Grunau , Alyssa Rosenzweig , Neal Gompa , Hector Martin , Linus Walleij , Bartosz Golaszewski , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Sebastian Reichel , Lee Jones , Marc Zyngier , "Russell King (Oracle)" Cc: asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=34376; i=sven@svenpeter.dev; h=from:subject:message-id; bh=Hrk982YpjStp8/4tdk+2L4q3gp9mAK+I6QkkRd9UbaI=; b=owGbwMvMwCHmIlirolUq95LxtFoSQ4boqxNzHWVa1HO21E9hCX659VJZt4tqBFdVs6SHftOGr Re1cq93lLIwiHEwyIopsmzfb2/65OEbwaWbLr2HmcPKBDKEgYtTACYyLYaRYQbHxSSGTYES6299 ifJo2Zhc/S066UDz/Y3xvBMfNJyY+Yfhv5vni2t/n6zc9+S5oOdSne5rSn/iGw/eclnuMCHi2O5 HaxkA X-Developer-Key: i=sven@svenpeter.dev; a=openpgp; fpr=A1E3E34A2B3C820DBC4955E5993B08092F131F93 X-Endpoint-Received: by B4 Relay for sven@svenpeter.dev/default with auth_id=167 X-Original-From: Sven Peter Reply-To: sven@svenpeter.dev From: Sven Peter The System Management Controller (SMC) on Apple Silicon machines is a piece of hardware that exposes various functionalities such as temperature sensors, voltage/power meters, shutdown/reboot handling, GPIOs and more. Communication happens via a shared mailbox using the RTKit protocol which is also used for other co-processors. The SMC protocol then allows reading and writing many different keys which implement the various features. The MFD core device handles this protocol and exposes it to the sub-devices. Some of the sub-devices are potentially also useful on pre-M1 Apple machines and support for SMCs on these machines can be added at a later time. Co-developed-by: Hector Martin Signed-off-by: Hector Martin Signed-off-by: Sven Peter --- MAINTAINERS | 2 + drivers/mfd/Kconfig | 15 ++ drivers/mfd/Makefile | 1 + drivers/mfd/macsmc.c | 657 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/macsmc.h | 337 +++++++++++++++++++++++ 5 files changed, 1012 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 2c16b2fc3fec76104967530f487123485af1e777..831df43892a64c95e00c24d77b8aa2a6ec87e074 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2300,6 +2300,7 @@ F: drivers/input/touchscreen/apple_z2.c F: drivers/iommu/apple-dart.c F: drivers/iommu/io-pgtable-dart.c F: drivers/irqchip/irq-apple-aic.c +F: drivers/mfd/macsmc.c F: drivers/nvme/host/apple.c F: drivers/nvmem/apple-efuses.c F: drivers/nvmem/apple-spmi-nvmem.c @@ -2312,6 +2313,7 @@ F: drivers/video/backlight/apple_dwi_bl.c F: drivers/watchdog/apple_wdt.c F: include/dt-bindings/interrupt-controller/apple-aic.h F: include/dt-bindings/pinctrl/apple.h +F: include/linux/mfd/macsmc.h F: include/linux/soc/apple/* ARM/ARTPEC MACHINE SUPPORT diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 22b93631003943c393d9fe704748bc23f1905397..da56fc4f05b7b7e0a521fcd97bee087424ec4d5b 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -285,6 +285,21 @@ config MFD_CS42L43_SDW Select this to support the Cirrus Logic CS42L43 PC CODEC with headphone and class D speaker drivers over SoundWire. +config MFD_MACSMC + tristate "Apple Silicon System Management Controller (SMC)" + select MFD_CORE + help + The System Management Controller (SMC) on Apple Silicon machines is a + piece of hardware that exposes various functionalities such as + temperature sensors, voltage/power meters, shutdown/reboot handling, + GPIOs and more. + + Communication happens via a shared mailbox using the RTKit protocol + which is also used for other co-processors. The SMC protocol then + allows reading and writing many different keys which implement the + various features. The MFD core device handles this protocol and + exposes it to the sub-devices. + config MFD_MADERA tristate "Cirrus Logic Madera codecs" select MFD_CORE diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 948cbdf42a18b22a826f0b17fb8d5796a7ec8ba6..e9e2403d961a631d9d63a274e0e4f6457ae9e0f2 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_MFD_CS42L43_SDW) += cs42l43-sdw.o obj-$(CONFIG_MFD_ENE_KB3930) += ene-kb3930.o obj-$(CONFIG_MFD_EXYNOS_LPASS) += exynos-lpass.o obj-$(CONFIG_MFD_GATEWORKS_GSC) += gateworks-gsc.o +obj-$(CONFIG_MFD_MACSMC) += macsmc.o obj-$(CONFIG_MFD_TI_LP873X) += lp873x.o obj-$(CONFIG_MFD_TI_LP87565) += lp87565.o diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c new file mode 100644 index 0000000000000000000000000000000000000000..59c2851b70f70a221434287cc99ef870a96f3659 --- /dev/null +++ b/drivers/mfd/macsmc.c @@ -0,0 +1,657 @@ +// SPDX-License-Identifier: GPL-2.0-only OR MIT +/* + * Apple SMC (System Management Controller) MFD driver + * + * Copyright The Asahi Linux Contributors + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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_RECV_TIMEOUT 500 + +static const struct mfd_cell apple_smc_devs[] = { + MFD_CELL_OF("macsmc-gpio", NULL, NULL, 0, 0, "apple,smc-gpio"), + MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"), +}; + +static int apple_smc_cmd_locked(struct apple_smc *smc, u64 cmd, u64 arg, + u64 size, u64 wsize, u32 *ret_data) +{ + int ret; + u64 msg; + u8 result; + + lockdep_assert_held(&smc->mutex); + + if (!smc->alive) + 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 < 0) { + dev_err(smc->dev, "Failed to send command\n"); + return ret; + } + + do { + if (wait_for_completion_timeout(&smc->cmd_done, + msecs_to_jiffies(SMC_RECV_TIMEOUT)) == 0) { + dev_err(smc->dev, "Command timed out (%llx)", msg); + return -ETIMEDOUT; + } + if (FIELD_GET(SMC_ID, smc->cmd_ret) == smc->msg_id) + break; + dev_err(smc->dev, "Command sequence mismatch (expected %d, got %d)\n", + smc->msg_id, (unsigned int)FIELD_GET(SMC_ID, smc->cmd_ret)); + } while (1); + + result = FIELD_GET(SMC_RESULT, smc->cmd_ret); + if (result != 0) + return -result; + + 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) +{ + int ret; + u64 cmd; + u64 smc_size, smc_wsize; + u32 rdata; + + lockdep_assert_held(&smc->mutex); + + dev_dbg(smc->dev, "SMC key: %p4ch, wsize: %zu, rsize: %zu\n", &key, wsize, rsize); + + 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, 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, 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_find_first_key_index(struct apple_smc *smc, smc_key key) +{ + int start, count; + + /* return early if the key is out of bounds */ + if (key <= smc->first_key) + return 0; + if (key > smc->last_key) + return smc->key_count; + + /* binary search to find index of first SMC key bigger or equal to key */ + start = 0; + count = smc->key_count; + while (count > 1) { + int ret; + smc_key pkey; + int pivot = start + ((count - 1) >> 1); + + ret = apple_smc_get_key_by_index(smc, pivot, &pkey); + if (ret < 0) + return ret; + + if (pkey == key) + return pivot; + + pivot++; + + if (pkey < key) { + count -= pivot - start; + start = pivot; + } else { + count = pivot - start; + } + } + + return start; +} +EXPORT_SYMBOL(apple_smc_find_first_key_index); + +int apple_smc_read_f32_scaled(struct apple_smc *smc, smc_key key, int *p, int scale) +{ + u32 fval; + u64 val; + int ret, exp; + + /* pretend the 4 bytes returned by SMC are a 32bit unsigned integer */ + ret = apple_smc_read_u32(smc, key, &fval); + if (ret < 0) + return ret; + + /* extract exponent and fraction from the IEEE 754 32bit float */ + val = ((u64)((fval & GENMASK(22, 0)) | BIT(23))); + exp = ((fval >> 23) & 0xff) - 127 - 23; + + /* move fraction to target scale */ + if (scale < 0) { + val <<= 32; + exp -= 32; + val /= -scale; + } else { + val *= scale; + } + + /* apply exponent if possible and fall back to 0 / U64_MAX on overflow */ + if (exp > 63) + val = U64_MAX; + else if (exp < -63) + val = 0; + else if (exp < 0) + val >>= -exp; + else if (exp != 0 && (val & ~((1UL << (64 - exp)) - 1))) /* overflow */ + val = U64_MAX; + else + val <<= exp; + + /* handle IEEE 754 32bit float sign bit and catch possible overflows */ + if (fval & BIT(31)) { + if (val > (-(s64)INT_MIN)) + *p = INT_MIN; + else + *p = -val; + } else { + if (val > INT_MAX) + *p = INT_MAX; + else + *p = val; + } + + return ret; +} +EXPORT_SYMBOL(apple_smc_read_f32_scaled); + +int apple_smc_read_ioft_scaled(struct apple_smc *smc, smc_key key, u64 *p, + int scale) +{ + u64 val; + int ret; + + ret = apple_smc_read_u64(smc, key, &val); + if (ret < 0) + return ret; + + /* + * The value val is represented in 48.16 fixed-point format, where + * the upper 48 bits represent the integer part and the lower 16 bits + * represent the fractional part. Dividing by 1 << 16 extracts the + * integer part by discarding the fractional portion. + * To scale the value as requested mult_frac is used to multiply val + * by the scaling factor while dividing by 1 << 16 in a single step. + */ + *p = mult_frac(val, scale, (1<<16)); + + return 0; +} +EXPORT_SYMBOL(apple_smc_read_ioft_scaled); + +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, void *buf, size_t size) +{ + guard(spinlock_irqsave)(&smc->lock); + int ret; + u64 msg; + u8 result; + + if (size > SMC_MAX_SIZE || size == 0) + return -EINVAL; + + if (!smc->alive) + 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 != 0) + return -result; + + 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; + + dev_err(smc->dev, "SMC crashed! Your system will reboot in a few seconds...\n"); + smc->alive = false; +} + +static int apple_smc_rtkit_shmem_setup(void *cookie, struct apple_rtkit_shmem *bfr) +{ + struct apple_smc *smc = cookie; + struct resource res = { + .start = bfr->iova, + .end = bfr->iova + bfr->size - 1, + .name = "rtkit_map", + .flags = smc->sram->flags, + }; + + if (!bfr->iova) { + dev_err(smc->dev, "RTKit wants a RAM buffer\n"); + return -EIO; + } + + if (res.end < res.start || !resource_contains(smc->sram, &res)) { + dev_err(smc->dev, + "RTKit buffer request outside SRAM region: %pR", &res); + return -EFAULT; + } + + bfr->iomem = smc->sram_base + (res.start - smc->sram->start); + bfr->is_mapped = true; + + return 0; +} + +static void apple_smc_rtkit_shmem_destroy(void *cookie, struct apple_rtkit_shmem *bfr) +{ + // no-op +} + +static bool apple_smc_rtkit_recv_early(void *cookie, u8 endpoint, u64 message) +{ + struct apple_smc *smc = cookie; + + if (endpoint != SMC_ENDPOINT) { + dev_err(smc->dev, "Received message for unknown endpoint 0x%x\n", endpoint); + return false; + } + + if (!smc->initialized) { + int ret; + + smc->shmem.iova = message; + smc->shmem.size = SMC_SHMEM_SIZE; + ret = apple_smc_rtkit_shmem_setup(smc, &smc->shmem); + if (ret < 0) + dev_err(smc->dev, "Failed to initialize shared memory\n"); + else + smc->alive = true; + smc->initialized = true; + 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; + uint32_t event; + + if (endpoint != SMC_ENDPOINT) { + dev_err(smc->dev, "Received message for unknown endpoint 0x%x\n", endpoint); + return; + } + + if (FIELD_GET(SMC_MSG, message) != SMC_MSG_NOTIFICATION) { + dev_err(smc->dev, "Received unknown message from worker: 0x%llx\n", message); + return; + } + + event = FIELD_GET(SMC_DATA, message); + dev_dbg(smc->dev, "Event: 0x%08x\n", event); + blocking_notifier_call_chain(&smc->event_handlers, event, 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, + .shmem_destroy = apple_smc_rtkit_shmem_destroy, +}; + +static int apple_smc_platform_probe(struct platform_device *pdev) +{ + int ret; + u32 count; + struct apple_smc *smc; + struct device *dev = &pdev->dev; + + smc = devm_kzalloc(dev, sizeof(*smc), GFP_KERNEL); + if (!smc) + return -ENOMEM; + + smc->dev = &pdev->dev; + smc->sram = platform_get_resource_byname(pdev, IORESOURCE_MEM, "sram"); + if (!smc->sram) + return dev_err_probe(dev, EIO, + "No SRAM region"); + + smc->sram_base = devm_ioremap_resource(dev, 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"); + + ret = apple_rtkit_wake(smc->rtk); + if (ret != 0) + return dev_err_probe(dev, ret, + "Failed to wake up SMC"); + + ret = apple_rtkit_start_ep(smc->rtk, SMC_ENDPOINT); + if (ret != 0) { + ret = dev_err_probe(dev, ret, + "Failed to start SMC endpoint"); + goto cleanup; + } + + 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 < 0) { + ret = dev_err_probe(dev, ret, "Failed to send init message"); + goto cleanup; + } + + if (wait_for_completion_timeout(&smc->init_done, + msecs_to_jiffies(SMC_RECV_TIMEOUT)) == 0) { + ret = -ETIMEDOUT; + dev_err(dev, "Timed out initializing SMC"); + goto cleanup; + } + + if (!smc->alive) { + ret = -EIO; + goto cleanup; + } + + 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) { + ret = dev_err_probe(smc->dev, ret, "Failed to get key count"); + goto cleanup; + } + smc->key_count = be32_to_cpu(count); + + ret = apple_smc_get_key_by_index(smc, 0, &smc->first_key); + if (ret) { + ret = dev_err_probe(smc->dev, ret, "Failed to get first key"); + goto cleanup; + } + + ret = apple_smc_get_key_by_index(smc, smc->key_count - 1, &smc->last_key); + if (ret) { + ret = dev_err_probe(smc->dev, ret, "Failed to get last key"); + goto cleanup; + } + + /* Enable notifications */ + apple_smc_write_flag(smc, SMC_KEY(NTAP), true); + + dev_info(smc->dev, "Initialized (%d keys %p4ch ... %p4ch)\n", + smc->key_count, &smc->first_key, &smc->last_key); + + ret = mfd_add_devices(smc->dev, -1, + apple_smc_devs, ARRAY_SIZE(apple_smc_devs), + NULL, 0, NULL); + if (ret) { + ret = dev_err_probe(smc->dev, ret, "Subdevice initialization failed"); + goto cleanup; + } + + return 0; + +cleanup: + /* Try to shut down RTKit, if it's not completely wedged */ + if (apple_rtkit_is_running(smc->rtk)) + apple_rtkit_quiesce(smc->rtk); + + return ret; +} + +static void apple_smc_platform_remove(struct platform_device *pdev) +{ + struct apple_smc *smc = platform_get_drvdata(pdev); + + mfd_remove_devices(smc->dev); + + /* Disable notifications */ + apple_smc_write_flag(smc, SMC_KEY(NTAP), false); + + /* Shut down SMC firmware */ + if (apple_rtkit_is_running(smc->rtk)) + apple_rtkit_quiesce(smc->rtk); +} + +static const struct of_device_id apple_smc_of_match[] = { + { .compatible = "apple,smc" }, + {}, +}; +MODULE_DEVICE_TABLE(of, apple_smc_of_match); + +static struct platform_driver apple_smc_driver = { + .driver = { + .name = "mfd-macsmc", + .owner = THIS_MODULE, + .of_match_table = apple_smc_of_match, + }, + .probe = apple_smc_platform_probe, + .remove = apple_smc_platform_remove, +}; +module_platform_driver(apple_smc_driver); + +MODULE_AUTHOR("Hector Martin "); +MODULE_AUTHOR("Sven Peter "); +MODULE_LICENSE("Dual MIT/GPL"); +MODULE_DESCRIPTION("Apple SMC driver"); diff --git a/include/linux/mfd/macsmc.h b/include/linux/mfd/macsmc.h new file mode 100644 index 0000000000000000000000000000000000000000..0b24b8e44dcb4564b50e6d2145f23f23321139c1 --- /dev/null +++ b/include/linux/mfd/macsmc.h @@ -0,0 +1,337 @@ +/* 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 + +/** + * 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. + */ +#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 + * @size: size of the buffer associated with this key + * @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) + * si8, ui8, si16, ui16, si32, ui32, si64, ui64: signed/unsigned 8-/16-/32-/64-bit integer + * @flags: bitfield encoding flags (APPLE_SMC_{READABLE,WRITABLE,FUNCTION}) + */ +struct apple_smc_key_info { + u8 size; + u32 type_code; + u8 flags; +}; + +/** + * 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 + * @initialized: flag indicating if SMC is initialized + * @alive: flag indicating if SMC is alive + * @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; + bool initialized; + bool alive; + + 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_find_first_key_index - find index of first SMC key bigger or equal to key + * @smc: pointer to apple_smc struct + * @key: smc_key to be found + * + * SMC keys are represented using either FourCC (which is stored as + * uint32_t / smc_key in this driver) or an index into the table of available + * keys which is sorted lexicographically. + * This function takes a FourCC key and uses binary search to find the + * index of the first SMC key that is lexicographically equal or bigger than the + * given input. + * This is required for e.g. the GPIO driver: GPIO keys start with gP + * and the driver has to find the first such key (by calling this function with + * key = SMC_KEY(gP00)) to be able to enumerate and register all available GPIOs + * at probe time. + * + * Return: Index of the first smc key that's bigger or equal to the given key. + * + * If the key is smaller than the first available key zero will be returned. + * If the key is bigger than the last available key smc->key_count (i.e. an out + * of bounds key) will be returned. + */ +int apple_smc_find_first_key_index(struct apple_smc *smc, smc_key key); + +/** + * apple_smc_key_exists - check if the given SMC key exists + * @smc: pointer to apple_smc struct + * @key: smc_key to be checked + */ +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); +} + +/** + * apple_smc_read_f32_scaled - read a float value from SMC and scale to a regular integer + * @smc: pointer to apple_smc struct + * @key: key to be read + * @p: pointer to integer that will be overwritten with the read value + * @scale: target scale + * + * Read a float value from the given SMC key and scale it to the given order + * of magnitude. If the value is smaller than the given scale zero will be + * used. If the value overflows an integer at the given scale p will be set to + * U64_MAX. + * + * This is useful for e.g. reading power consumption, which is reported by SMC + * in Watt (W) as a floating point number, and scale it to uW like so: + * + * apple_smc_read_f32_scaled(smc, SMC_KEY(PSTR), &power_uW, 1000000); + * + * At that scale, noise starts to dominate the power measurements anyway and + * there's no reason to deal with floats. + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_read_f32_scaled(struct apple_smc *smc, smc_key key, int *p, int scale); + +/** + * apple_smc_read_ioft_scaled - read a 48.16 fixed point from SMC and scale to a regular integer + * @smc: pointer to apple_smc struct + * @key: key to be read + * @p: pointer to integer that will be overwritten with the read value + * @scale: target scale + * + * Read a 48.16 fixed point value from the given SMC key and scale it to the + * given order of magnitude. If the value is smaller than the given scale zero + * will be used. If the value overflows an integer at the given scale p will be + * set to U64_MAX. + * + * This is useful for e.g. reading temperature, which is reported by SMC in + * degrees as a 48.16 fixed point number, and scale it to milli-degrees Celsius + * like so: + * + * apple_smc_read_ioft_scaled(smc, SMC_KEY(TR0Z), &temperature_mC, 1000); + * + * Reporting temperature with more precision runs into measurements errors and + * isn't very useful such that using a simple integer instead of fixed point + * numbers is reasonable. + * + * Return: Zero on success, negative errno on error + */ +int apple_smc_read_ioft_scaled(struct apple_smc *smc, smc_key key, u64 *p, int scale); + +#endif