From: Hector Martin <marcan@marcan.st>
This driver implements the reboot/shutdown support exposed by the SMC
on Apple Silicon machines, such as Apple M1 Macs.
Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sven Peter <sven@kernel.org>
---
MAINTAINERS | 1 +
drivers/power/reset/Kconfig | 9 ++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/macsmc-reboot.c | 290 ++++++++++++++++++++++++++++++++++++
4 files changed, 301 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c1977d0af7c99aaef38a89e5d7eb32f42c4565f..9a3f273c557fbb24fe8b6f77d9df3c026b898e7a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2370,6 +2370,7 @@ F: drivers/nvme/host/apple.c
F: drivers/nvmem/apple-efuses.c
F: drivers/nvmem/apple-spmi-nvmem.c
F: drivers/pinctrl/pinctrl-apple-gpio.c
+F: drivers/power/reset/macsmc-reboot.c
F: drivers/pwm/pwm-apple.c
F: drivers/soc/apple/*
F: drivers/spi/spi-apple.c
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index e71f0af4e378c1d0e5a73bdf0b52262976fff190..733d812621599dadffb8303b6b95150c228f6426 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -128,6 +128,15 @@ config POWER_RESET_LINKSTATION
Say Y here if you have a Buffalo LinkStation LS421D/E.
+config POWER_RESET_MACSMC
+ tristate "Apple SMC reset/power-off driver"
+ depends on MFD_MACSMC
+ help
+ This driver supports reset and power-off on Apple Mac machines
+ that implement this functionality via the SMC.
+
+ Say Y here if you have an Apple Silicon Mac.
+
config POWER_RESET_MSM
bool "Qualcomm MSM power-off driver"
depends on ARCH_QCOM
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 1b9b63a1a8731b765c0010e02543083dd184ee6c..b7c2b5940be9971548a5527384d1931abff11c4c 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
obj-$(CONFIG_POWER_RESET_LINKSTATION) += linkstation-poweroff.o
+obj-$(CONFIG_POWER_RESET_MACSMC) += macsmc-reboot.o
obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o
obj-$(CONFIG_POWER_RESET_QCOM_PON) += qcom-pon.o
diff --git a/drivers/power/reset/macsmc-reboot.c b/drivers/power/reset/macsmc-reboot.c
new file mode 100644
index 0000000000000000000000000000000000000000..e9702acdd366b053ce7a032bb09f636ac5c02444
--- /dev/null
+++ b/drivers/power/reset/macsmc-reboot.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SMC Reboot/Poweroff Handler
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/delay.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/macsmc.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/slab.h>
+
+struct macsmc_reboot_nvmem {
+ struct nvmem_cell *shutdown_flag;
+ struct nvmem_cell *boot_stage;
+ struct nvmem_cell *boot_error_count;
+ struct nvmem_cell *panic_count;
+};
+
+static const char * const nvmem_names[] = {
+ "shutdown_flag",
+ "boot_stage",
+ "boot_error_count",
+ "panic_count",
+};
+
+enum boot_stage {
+ BOOT_STAGE_SHUTDOWN = 0x00, /* Clean shutdown */
+ BOOT_STAGE_IBOOT_DONE = 0x2f, /* Last stage of bootloader */
+ BOOT_STAGE_KERNEL_STARTED = 0x30, /* Normal OS booting */
+};
+
+struct macsmc_reboot {
+ struct device *dev;
+ struct apple_smc *smc;
+ struct notifier_block reboot_notify;
+
+ union {
+ struct macsmc_reboot_nvmem nvm;
+ struct nvmem_cell *nvm_cells[ARRAY_SIZE(nvmem_names)];
+ };
+};
+
+/* Helpers to read/write a u8 given a struct nvmem_cell */
+static int nvmem_cell_get_u8(struct nvmem_cell *cell)
+{
+ size_t len;
+ void *bfr;
+ u8 val;
+
+ bfr = nvmem_cell_read(cell, &len);
+ if (IS_ERR(bfr))
+ return PTR_ERR(bfr);
+
+ if (len < 1) {
+ kfree(bfr);
+ return -EINVAL;
+ }
+
+ val = *(u8 *)bfr;
+ kfree(bfr);
+ return val;
+}
+
+static int nvmem_cell_set_u8(struct nvmem_cell *cell, u8 val)
+{
+ return nvmem_cell_write(cell, &val, sizeof(val));
+}
+
+/*
+ * SMC 'MBSE' key actions:
+ *
+ * 'offw' - shutdown warning
+ * 'slpw' - sleep warning
+ * 'rest' - restart warning
+ * 'off1' - shutdown (needs PMU bit set to stay on)
+ * 'susp' - suspend
+ * 'phra' - restart ("PE Halt Restart Action"?)
+ * 'panb' - panic beginning
+ * 'pane' - panic end
+ */
+
+static int macsmc_prepare_atomic(struct sys_off_data *data)
+{
+ struct macsmc_reboot *reboot = data->cb_data;
+
+ dev_info(reboot->dev, "Preparing SMC for atomic mode\n");
+
+ apple_smc_enter_atomic(reboot->smc);
+ return NOTIFY_OK;
+}
+
+static int macsmc_power_off(struct sys_off_data *data)
+{
+ struct macsmc_reboot *reboot = data->cb_data;
+
+ dev_info(reboot->dev, "Issuing power off (off1)\n");
+
+ if (apple_smc_write_u32_atomic(reboot->smc, SMC_KEY(MBSE), SMC_KEY(off1)) < 0) {
+ dev_err(reboot->dev, "Failed to issue MBSE = off1 (power_off)\n");
+ } else {
+ mdelay(100);
+ WARN_ONCE(1, "Unable to power off system\n");
+ }
+
+ return NOTIFY_OK;
+}
+
+static int macsmc_restart(struct sys_off_data *data)
+{
+ struct macsmc_reboot *reboot = data->cb_data;
+
+ dev_info(reboot->dev, "Issuing restart (phra)\n");
+
+ if (apple_smc_write_u32_atomic(reboot->smc, SMC_KEY(MBSE), SMC_KEY(phra)) < 0) {
+ dev_err(reboot->dev, "Failed to issue MBSE = phra (restart)\n");
+ } else {
+ mdelay(100);
+ WARN_ONCE(1, "Unable to restart system\n");
+ }
+
+ return NOTIFY_OK;
+}
+
+static int macsmc_reboot_notify(struct notifier_block *this, unsigned long action, void *data)
+{
+ struct macsmc_reboot *reboot = container_of(this, struct macsmc_reboot, reboot_notify);
+ u8 shutdown_flag;
+ u32 val;
+
+ switch (action) {
+ case SYS_RESTART:
+ val = SMC_KEY(rest);
+ shutdown_flag = 0;
+ break;
+ case SYS_POWER_OFF:
+ val = SMC_KEY(offw);
+ shutdown_flag = 1;
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ dev_info(reboot->dev, "Preparing for reboot (%p4ch)\n", &val);
+
+ /* On the Mac Mini, this will turn off the LED for power off */
+ if (apple_smc_write_u32(reboot->smc, SMC_KEY(MBSE), val) < 0)
+ dev_err(reboot->dev, "Failed to issue MBSE = %p4ch (reboot_prepare)\n", &val);
+
+ /* Set the boot_stage to 0, which means we're doing a clean shutdown/reboot. */
+ if (reboot->nvm.boot_stage &&
+ nvmem_cell_set_u8(reboot->nvm.boot_stage, BOOT_STAGE_SHUTDOWN) < 0)
+ dev_err(reboot->dev, "Failed to write boot_stage\n");
+
+ /*
+ * Set the PMU flag to actually reboot into the off state.
+ * Without this, the device will just reboot. We make it optional in case it is no longer
+ * necessary on newer hardware.
+ */
+ if (reboot->nvm.shutdown_flag &&
+ nvmem_cell_set_u8(reboot->nvm.shutdown_flag, shutdown_flag) < 0)
+ dev_err(reboot->dev, "Failed to write shutdown_flag\n");
+
+ return NOTIFY_OK;
+}
+
+static void macsmc_power_init_error_counts(struct macsmc_reboot *reboot)
+{
+ int boot_error_count, panic_count;
+
+ if (!reboot->nvm.boot_error_count || !reboot->nvm.panic_count)
+ return;
+
+ boot_error_count = nvmem_cell_get_u8(reboot->nvm.boot_error_count);
+ if (boot_error_count < 0) {
+ dev_err(reboot->dev, "Failed to read boot_error_count (%d)\n", boot_error_count);
+ return;
+ }
+
+ panic_count = nvmem_cell_get_u8(reboot->nvm.panic_count);
+ if (panic_count < 0) {
+ dev_err(reboot->dev, "Failed to read panic_count (%d)\n", panic_count);
+ return;
+ }
+
+ if (!boot_error_count && !panic_count)
+ return;
+
+ dev_warn(reboot->dev, "PMU logged %d boot error(s) and %d panic(s)\n",
+ boot_error_count, panic_count);
+
+ if (nvmem_cell_set_u8(reboot->nvm.panic_count, 0) < 0)
+ dev_err(reboot->dev, "Failed to reset panic_count\n");
+ if (nvmem_cell_set_u8(reboot->nvm.boot_error_count, 0) < 0)
+ dev_err(reboot->dev, "Failed to reset boot_error_count\n");
+}
+
+static int macsmc_reboot_probe(struct platform_device *pdev)
+{
+ struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
+ struct macsmc_reboot *reboot;
+ int ret, i;
+
+ reboot = devm_kzalloc(&pdev->dev, sizeof(*reboot), GFP_KERNEL);
+ if (!reboot)
+ return -ENOMEM;
+
+ reboot->dev = &pdev->dev;
+ reboot->smc = smc;
+
+ platform_set_drvdata(pdev, reboot);
+
+ for (i = 0; i < ARRAY_SIZE(nvmem_names); i++) {
+ struct nvmem_cell *cell;
+
+ cell = devm_nvmem_cell_get(&pdev->dev,
+ nvmem_names[i]);
+ if (IS_ERR(cell)) {
+ if (PTR_ERR(cell) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ dev_warn(&pdev->dev, "Missing NVMEM cell %s (%ld)\n",
+ nvmem_names[i], PTR_ERR(cell));
+ /* Non fatal, we'll deal with it */
+ cell = NULL;
+ }
+ reboot->nvm_cells[i] = cell;
+ }
+
+ /* Set the boot_stage to indicate we're running the OS kernel */
+ if (reboot->nvm.boot_stage &&
+ nvmem_cell_set_u8(reboot->nvm.boot_stage, BOOT_STAGE_KERNEL_STARTED) < 0)
+ dev_err(reboot->dev, "Failed to write boot_stage\n");
+
+ /* Display and clear the error counts */
+ macsmc_power_init_error_counts(reboot);
+
+ reboot->reboot_notify.notifier_call = macsmc_reboot_notify;
+
+ ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_POWER_OFF_PREPARE,
+ SYS_OFF_PRIO_HIGH, macsmc_prepare_atomic, reboot);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "Failed to register power-off prepare handler\n");
+ ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_HIGH,
+ macsmc_power_off, reboot);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "Failed to register power-off handler\n");
+
+ ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART_PREPARE,
+ SYS_OFF_PRIO_HIGH, macsmc_prepare_atomic, reboot);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "Failed to register restart prepare handler\n");
+ ret = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART, SYS_OFF_PRIO_HIGH,
+ macsmc_restart, reboot);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to register restart handler\n");
+
+ ret = devm_register_reboot_notifier(&pdev->dev, &reboot->reboot_notify);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "Failed to register reboot notifier\n");
+
+ dev_info(&pdev->dev, "Handling reboot and poweroff requests via SMC\n");
+
+ return 0;
+}
+
+static const struct of_device_id macsmc_reboot_of_table[] = {
+ { .compatible = "apple,smc-reboot", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, macsmc_reboot_of_table);
+
+static struct platform_driver macsmc_reboot_driver = {
+ .driver = {
+ .name = "macsmc-reboot",
+ .of_match_table = macsmc_reboot_of_table,
+ },
+ .probe = macsmc_reboot_probe,
+};
+module_platform_driver(macsmc_reboot_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_DESCRIPTION("Apple SMC reboot/poweroff driver");
+MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");
--
2.34.1On 10/6/2025 23:29, Sven Peter wrote: > From: Hector Martin <marcan@marcan.st> > > This driver implements the reboot/shutdown support exposed by the SMC > on Apple Silicon machines, such as Apple M1 Macs. > > Signed-off-by: Hector Martin <marcan@marcan.st> > Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io> > Reviewed-by: Neal Gompa <neal@gompa.dev> > Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com> > Signed-off-by: Sven Peter <sven@kernel.org> > --- > MAINTAINERS | 1 + > drivers/power/reset/Kconfig | 9 ++ > drivers/power/reset/Makefile | 1 + > drivers/power/reset/macsmc-reboot.c | 290 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 301 insertions(+) [...] It seems that the reboot driver still probes even without the smc_reboot node in the smc node: [ 0.994942] macsmc 236000100.smc: RTKit: Initializing (protocol version 12) [ 1.002862] macsmc-gpio macsmc-gpio: First GPIO key: gP01 (0x67503031) [ 1.013156] macsmc-reboot: Failed to locate of_node [id: -1] [ 1.048188] macsmc-reboot macsmc-reboot: Missing NVMEM cell shutdown_flag (-2) [ 1.055359] macsmc-reboot macsmc-reboot: Missing NVMEM cell boot_stage (-2) [ 1.062332] macsmc-reboot macsmc-reboot: Missing NVMEM cell boot_error_count (-2) [ 1.069799] macsmc-reboot macsmc-reboot: Missing NVMEM cell panic_count (-2) [ 1.076902] macsmc-reboot macsmc-reboot: Handling reboot and poweroff requests via SMC Best regards, Nick Chan
On 16.06.25 06:13, Nick Chan wrote:
>
>
> On 10/6/2025 23:29, Sven Peter wrote:
>> From: Hector Martin <marcan@marcan.st>
>>
>> This driver implements the reboot/shutdown support exposed by the SMC
>> on Apple Silicon machines, such as Apple M1 Macs.
>>
>> Signed-off-by: Hector Martin <marcan@marcan.st>
>> Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
>> Reviewed-by: Neal Gompa <neal@gompa.dev>
>> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
>> Signed-off-by: Sven Peter <sven@kernel.org>
>> ---
>> MAINTAINERS | 1 +
>> drivers/power/reset/Kconfig | 9 ++
>> drivers/power/reset/Makefile | 1 +
>> drivers/power/reset/macsmc-reboot.c | 290 ++++++++++++++++++++++++++++++++++++
>> 4 files changed, 301 insertions(+)
> [...]
>
> It seems that the reboot driver still probes even without the smc_reboot node in the smc node:
That's odd...
Lee, is it expected that a mfd sub-device declared with
MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"),
is loaded even if there's no corresponding node in the device tree?
I'll have to re-add the check that makes sure the sub-device is
available then.
Thanks,
Sven
On Sat, 21 Jun 2025, Sven Peter wrote:
> On 16.06.25 06:13, Nick Chan wrote:
> >
> >
> > On 10/6/2025 23:29, Sven Peter wrote:
> > > From: Hector Martin <marcan@marcan.st>
> > >
> > > This driver implements the reboot/shutdown support exposed by the SMC
> > > on Apple Silicon machines, such as Apple M1 Macs.
> > >
> > > Signed-off-by: Hector Martin <marcan@marcan.st>
> > > Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
> > > Reviewed-by: Neal Gompa <neal@gompa.dev>
> > > Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > > Signed-off-by: Sven Peter <sven@kernel.org>
> > > ---
> > > MAINTAINERS | 1 +
> > > drivers/power/reset/Kconfig | 9 ++
> > > drivers/power/reset/Makefile | 1 +
> > > drivers/power/reset/macsmc-reboot.c | 290 ++++++++++++++++++++++++++++++++++++
> > > 4 files changed, 301 insertions(+)
> > [...]
> >
> > It seems that the reboot driver still probes even without the smc_reboot node in the smc node:
>
>
> That's odd...
>
> Lee, is it expected that a mfd sub-device declared with
> MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"),
> is loaded even if there's no corresponding node in the device tree?
>
> I'll have to re-add the check that makes sure the sub-device is available
> then.
Yes, that's expected. MFD is orthogonal to DT with respect to device
registration, unless you specifically disable the node in DT. If the
node is missing, the device will still be registered, but no link will
be made from the (non-existent) node to the 'of_node' pointer.
You have 3 choices; provide a DT node and explicitly set the status to
'disabled', optionally omit registration from MFD (i.e. do not call
mfd_add_devices()) or check for (!pdev->dev.of_node) in the sub-device's
.probe() and bomb out early if true.
--
Lee Jones [李琼斯]
On 23.07.25 10:06, Lee Jones wrote:
> On Sat, 21 Jun 2025, Sven Peter wrote:
>
>> On 16.06.25 06:13, Nick Chan wrote:
>>>
>>>
>>> On 10/6/2025 23:29, Sven Peter wrote:
>>>> From: Hector Martin <marcan@marcan.st>
>>>>
>>>> This driver implements the reboot/shutdown support exposed by the SMC
>>>> on Apple Silicon machines, such as Apple M1 Macs.
>>>>
>>>> Signed-off-by: Hector Martin <marcan@marcan.st>
>>>> Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
>>>> Reviewed-by: Neal Gompa <neal@gompa.dev>
>>>> Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
>>>> Signed-off-by: Sven Peter <sven@kernel.org>
>>>> ---
>>>> MAINTAINERS | 1 +
>>>> drivers/power/reset/Kconfig | 9 ++
>>>> drivers/power/reset/Makefile | 1 +
>>>> drivers/power/reset/macsmc-reboot.c | 290 ++++++++++++++++++++++++++++++++++++
>>>> 4 files changed, 301 insertions(+)
>>> [...]
>>>
>>> It seems that the reboot driver still probes even without the smc_reboot node in the smc node:
>>
>>
>> That's odd...
>>
>> Lee, is it expected that a mfd sub-device declared with
>> MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"),
>> is loaded even if there's no corresponding node in the device tree?
>>
>> I'll have to re-add the check that makes sure the sub-device is available
>> then.
>
> Yes, that's expected. MFD is orthogonal to DT with respect to device
> registration, unless you specifically disable the node in DT. If the
> node is missing, the device will still be registered, but no link will
> be made from the (non-existent) node to the 'of_node' pointer.
Makes sense!
>
> You have 3 choices; provide a DT node and explicitly set the status to
> 'disabled', optionally omit registration from MFD (i.e. do not call
> mfd_add_devices()) or check for (!pdev->dev.of_node) in the sub-device's
> .probe() and bomb out early if true.
>
Alright, so everything's working as intended then and the series has all
required Acks. I'd suggest that we take it as-is then (either now if
you're still picking things up before the merge window or after -rc1 is
out otherwise) since it only adds support for M1 and later and those
have all subdevices added here.
Once Nick adds support for pre-M1 SMC we can do one of those three
things to disable the reboot sub-device then.
Best,
Sven
On Wed, 23 Jul 2025, Lee Jones wrote:
> On Sat, 21 Jun 2025, Sven Peter wrote:
>
> > On 16.06.25 06:13, Nick Chan wrote:
> > >
> > >
> > > On 10/6/2025 23:29, Sven Peter wrote:
> > > > From: Hector Martin <marcan@marcan.st>
> > > >
> > > > This driver implements the reboot/shutdown support exposed by the SMC
> > > > on Apple Silicon machines, such as Apple M1 Macs.
> > > >
> > > > Signed-off-by: Hector Martin <marcan@marcan.st>
> > > > Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
> > > > Reviewed-by: Neal Gompa <neal@gompa.dev>
> > > > Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> > > > Signed-off-by: Sven Peter <sven@kernel.org>
> > > > ---
> > > > MAINTAINERS | 1 +
> > > > drivers/power/reset/Kconfig | 9 ++
> > > > drivers/power/reset/Makefile | 1 +
> > > > drivers/power/reset/macsmc-reboot.c | 290 ++++++++++++++++++++++++++++++++++++
> > > > 4 files changed, 301 insertions(+)
> > > [...]
> > >
> > > It seems that the reboot driver still probes even without the smc_reboot node in the smc node:
> >
> >
> > That's odd...
> >
> > Lee, is it expected that a mfd sub-device declared with
> > MFD_CELL_OF("macsmc-reboot", NULL, NULL, 0, 0, "apple,smc-reboot"),
> > is loaded even if there's no corresponding node in the device tree?
> >
> > I'll have to re-add the check that makes sure the sub-device is available
> > then.
>
> Yes, that's expected. MFD is orthogonal to DT with respect to device
> registration, unless you specifically disable the node in DT. If the
> node is missing, the device will still be registered, but no link will
> be made from the (non-existent) node to the 'of_node' pointer.
>
> You have 3 choices; provide a DT node and explicitly set the status to
> 'disabled', optionally omit registration from MFD (i.e. do not call
> mfd_add_devices()) or check for (!pdev->dev.of_node) in the sub-device's
> .probe() and bomb out early if true.
Did you see this warning in your bootlog:
pr_warn("%s: Failed to locate of_node [id: %d]\n", cell->name, platform_id);
It's just a warning - the device will still be registered.
--
Lee Jones [李琼斯]
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