[PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[James Calligeros]

Hi all,

This series adds support for the remaining SMC subdevices. These are the
RTC, hwmon, and HID devices. They are being submitted together as the RTC
and hwmon drivers both require changes to the SMC DT schema.

The RTC driver is responsible for getting and setting the system clock,
and requires an NVMEM cell. This series replaces Sven's original RTC driver
submission [1].

The hwmon function is an interesting one. While each Apple Silicon device
exposes pretty similar sets of sensors, these all seem to be paired to
different SMC keys in the firmware interface. This is true even when the
sensors are on the SoC. For example, an M1 MacBook Pro will use different
keys to access the LITTLE core temperature sensors to an M1 Mac mini. This
necessitates describing which keys correspond to which sensors for each
device individually, and populating the hwmon structs at runtime. We do
this with a node in the device tree. This series includes only the keys
for sensors which we know to be common to all devices. The SMC is also
responsible for monitoring and controlling fan speeds on systems with fans,
which we expose via the hwmon driver.

The SMC also handles the hardware power button and lid switch. Power
button presses and lid opening/closing are emitted as HID events, so we
add a HID subdevice to handle them.

Note that this series is based on a branch with three additional commits
applied to add the parent SMC nodes to the relevant Devicetrees. This
was done to silence build errors. The series applies cleanly to 6.17-rc1.

Regards,

James

[1] https://lore.kernel.org/asahi/CAEg-Je84XxLWH7vznQmPRfjf6GxWOu75ZetwN7AdseAwfMLLrQ@mail.gmail.com/T/#t

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
Changes in v2:
- Added Rob's R-b tag to RTC DT binding
- Removed redundant nesting from hwmon DT binding
- Dedpulicated property definitions in hwmon DT schema
- Made label a required property for hwmon DT nodes
- Clarified semantics in hwmon DT schema definitions
- Split mfd tree changes into separate commits
- Fixed numerous style errors in hwmon driver
- Addressed Guenter's initial feedback on the hwmon driver
- Modified hwmon driver to reflect DT schema changes
- Added compatible property to hwmon node
- Link to v1: https://lore.kernel.org/r/20250819-macsmc-subdevs-v1-0-57df6c3e5f19@gmail.com

---
Hector Martin (2):
      rtc: Add new rtc-macsmc driver for Apple Silicon Macs
      input: macsmc-hid: New driver to handle the Apple Mac SMC buttons/lid

James Calligeros (7):
      dt-bindings: hwmon: Add Apple System Management Controller hwmon schema
      mfd: macsmc: Wire up Apple SMC RTC subdevice
      hwmon: Add Apple Silicon SMC hwmon driver
      mfd: macsmc: Wire up Apple SMC hwmon subdevice
      mfd: macsmc: Wire up Apple SMC HID subdevice
      arm64: dts: apple: Add common hwmon sensors and fans
      arm64: dts: apple: t8103, t600x, t8112: Add common hwmon nodes to devices

Sven Peter (2):
      dt-bindings: rtc: Add Apple SMC RTC
      arm64: dts: apple: t8103,t600x,t8112: Add SMC RTC node

 .../bindings/hwmon/apple,smc-hwmon.yaml  | 132 ++++
 .../bindings/mfd/apple,smc.yaml          |  45 ++
 .../bindings/rtc/apple,smc-rtc.yaml      |  35 +
 MAINTAINERS                              |   5 +
 .../boot/dts/apple/hwmon-common.dtsi     |  37 ++
 .../boot/dts/apple/hwmon-fan-dual.dtsi   |  24 +
 arch/arm64/boot/dts/apple/hwmon-fan.dtsi |  19 +
 .../boot/dts/apple/hwmon-laptop.dtsi     |  35 +
 .../boot/dts/apple/hwmon-mac-mini.dtsi   |  17 +
 .../arm64/boot/dts/apple/t6001-j375c.dts |   2 +
 .../arm64/boot/dts/apple/t6002-j375d.dts |   2 +
 .../arm64/boot/dts/apple/t600x-die0.dtsi |   6 +
 .../boot/dts/apple/t600x-j314-j316.dtsi  |   4 +
 .../arm64/boot/dts/apple/t600x-j375.dtsi |   2 +
 arch/arm64/boot/dts/apple/t8103-j274.dts |   2 +
 arch/arm64/boot/dts/apple/t8103-j293.dts |   3 +
 arch/arm64/boot/dts/apple/t8103-j313.dts |   2 +
 arch/arm64/boot/dts/apple/t8103-j456.dts |   2 +
 arch/arm64/boot/dts/apple/t8103-j457.dts |   2 +
 .../arm64/boot/dts/apple/t8103-jxxx.dtsi |   2 +
 arch/arm64/boot/dts/apple/t8103.dtsi     |   6 +
 arch/arm64/boot/dts/apple/t8112-j413.dts |   2 +
 arch/arm64/boot/dts/apple/t8112-j473.dts |   2 +
 arch/arm64/boot/dts/apple/t8112-j493.dts |   3 +
 .../arm64/boot/dts/apple/t8112-jxxx.dtsi |   2 +
 arch/arm64/boot/dts/apple/t8112.dtsi     |   6 +
 drivers/hwmon/Kconfig                    |  12 +
 drivers/hwmon/Makefile                   |   1 +
 drivers/hwmon/macsmc_hwmon.c             | 848 +++++++++++++++++++++++++
 drivers/input/misc/Kconfig               |  11 +
 drivers/input/misc/Makefile              |   1 +
 drivers/input/misc/macsmc-hid.c          | 209 ++++++
 drivers/mfd/macsmc.c                     |   3 +
 drivers/rtc/Kconfig                      |  11 +
 drivers/rtc/Makefile                     |   1 +
 drivers/rtc/rtc-macsmc.c                 | 141 ++++
 36 files changed, 1637 insertions(+)
---
base-commit: 876d6a70b24869f96ebc8672caf86cb4bae72927
change-id: 20250816-macsmc-subdevs-87032c017d0c

Best regards,
-- 
James Calligeros <jcalligeros99@gmail.com>

[PATCH v2 01/11] dt-bindings: rtc: Add Apple SMC RTC

[James Calligeros]

From: Sven Peter <sven@kernel.org>

Apple Silicon Macs (M1, etc.) have an RTC that is part of the PMU IC,
but most of the PMU functionality is abstracted out by the SMC.
An additional RTC offset stored inside NVMEM is required to compute
the current date/time.

Reviewed-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Sven Peter <sven@kernel.org>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 .../bindings/mfd/apple,smc.yaml          |  9 +++++++
 .../bindings/rtc/apple,smc-rtc.yaml      | 35 +++++++++++++++++++++++++
 MAINTAINERS                              |  1 +
 3 files changed, 45 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/apple,smc.yaml b/Documentation/devicetree/bindings/mfd/apple,smc.yaml
index 8a10e270d421ecd703848f64af597de351fcfd74..38f077867bdeedba8a486a63e366e9c943a75681 100644
--- a/Documentation/devicetree/bindings/mfd/apple,smc.yaml
+++ b/Documentation/devicetree/bindings/mfd/apple,smc.yaml
@@ -41,6 +41,9 @@ properties:
   reboot:
     $ref: /schemas/power/reset/apple,smc-reboot.yaml
 
+  rtc:
+    $ref: /schemas/rtc/apple,smc-rtc.yaml
+
 additionalProperties: false
 
 required:
@@ -75,5 +78,11 @@ examples:
           nvmem-cell-names = "shutdown_flag", "boot_stage",
                              "boot_error_count", "panic_count";
         };
+
+        rtc {
+          compatible = "apple,smc-rtc";
+          nvmem-cells = <&rtc_offset>;
+          nvmem-cell-names = "rtc_offset";
+       };
       };
     };
diff --git a/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml b/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..607b610665a28b3ea2e86bd90cb5f3f28ebac726
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/rtc/apple,smc-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SMC RTC
+
+description:
+  Apple Silicon Macs (M1, etc.) have an RTC that is part of the PMU IC,
+  but most of the PMU functionality is abstracted out by the SMC.
+  An additional RTC offset stored inside NVMEM is required to compute
+  the current date/time.
+
+maintainers:
+  - Sven Peter <sven@kernel.org>
+
+properties:
+  compatible:
+    const: apple,smc-rtc
+
+  nvmem-cells:
+    items:
+      - description: 48bit RTC offset, specified in 32768 (2^15) Hz clock ticks
+
+  nvmem-cell-names:
+    items:
+      - const: rtc_offset
+
+required:
+  - compatible
+  - nvmem-cells
+  - nvmem-cell-names
+
+additionalProperties: false
diff --git a/MAINTAINERS b/MAINTAINERS
index fe168477caa45799dfe07de2f54de6d6a1ce0615..aaef8634985b35f54de1123ebb4176602066d177 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2397,6 +2397,7 @@ F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
 F:	Documentation/devicetree/bindings/power/apple*
 F:	Documentation/devicetree/bindings/power/reset/apple,smc-reboot.yaml
 F:	Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
+F:	Documentation/devicetree/bindings/rtc/apple,smc-rtc.yaml
 F:	Documentation/devicetree/bindings/spi/apple,spi.yaml
 F:	Documentation/devicetree/bindings/spmi/apple,spmi.yaml
 F:	Documentation/devicetree/bindings/watchdog/apple,wdt.yaml

-- 
2.51.0

[PATCH v2 02/11] dt-bindings: hwmon: Add Apple System Management Controller hwmon schema

[James Calligeros]

Apple Silicon devices integrate a vast array of sensors, monitoring
current, power, temperature, and voltage across almost every part of
the system. The sensors themselves are all connected to the System
Management Controller (SMC). The SMC firmware exposes the data
reported by these sensors via its standard FourCC-based key-value
API. The SMC is also responsible for monitoring and controlling any
fans connected to the system, exposing them in the same way.

For reasons known only to Apple, each device exposes its sensors with
an almost totally unique set of keys. This is true even for devices
which share an SoC. An M1 Mac mini, for example, will report its core
temperatures on different keys to an M1 MacBook Pro. Worse still, the
SMC does not provide a way to enumerate the available keys at runtime,
nor do the keys follow any sort of reasonable or consistent naming
rules that could be used to deduce their purpose. We must therefore
know which keys are present on any given device, and which function
they serve, ahead of time.

Add a schema so that we can describe the available sensors for a given
Apple Silicon device in the Devicetree.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 .../bindings/hwmon/apple,smc-hwmon.yaml  | 132 +++++++++++++++++++++++++
 .../bindings/mfd/apple,smc.yaml          |  36 +++++++
 MAINTAINERS                              |   1 +
 3 files changed, 169 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml b/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..08cc4f55f3a41ca8b3b428088f96240266fa42e8
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
@@ -0,0 +1,132 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/apple,smc-hwmon.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SMC Hardware Monitoring
+
+description:
+  Apple's System Management Controller (SMC) exposes a vast array of
+  hardware monitoring sensors, including temperature probes, current and
+  voltage sense, power meters, and fan speeds. It also provides endpoints
+  to manually control the speed of each fan individually. Each Apple
+  Silicon device exposes a different set of endpoints via SMC keys. This
+  is true even when two machines share an SoC. The CPU core temperature
+  sensor keys on an M1 Mac mini are different to those on an M1 MacBook
+  Pro, for example.
+
+maintainers:
+  - James Calligeros <jcalligeros99@gmail.com>
+
+definitions:
+  apple,key-id:
+    $ref: /schemas/types.yaml#/definitions/string
+    pattern: "^[A-Za-z0-9]{4}$"
+    description: The SMC FourCC key of the desired sensor.
+      Must match the node's suffix.
+
+  label:
+    description: Human-readable name for the sensor
+
+properties:
+  compatible:
+    const: apple,smc-hwmon
+
+patternProperties:
+  "^current-[A-Za-z0-9]{4}$":
+    type: object
+    additionalProperties: false
+
+    properties:
+      apple,key-id:
+        $ref: "#/definitions/apple,key-id"
+
+      label:
+        $ref: "#/definitions/label"
+
+    required:
+      - apple,key-id
+      - label
+
+  "^fan-[A-Za-z0-9]{4}$":
+    type: object
+    additionalProperties: false
+
+    properties:
+      apple,key-id:
+        $ref: "#/definitions/apple,key-id"
+
+      apple,fan-minimum:
+        $ref: /schemas/types.yaml#/definitions/string
+        pattern: "^[A-Za-z0-9]{4}$"
+        description: SMC key containing the fan's minimum speed
+
+      apple,fan-maximum:
+        $ref: /schemas/types.yaml#/definitions/string
+        pattern: "^[A-Za-z0-9]{4}$"
+        description: SMC key containing the fan's maximum speed
+
+      apple,fan-target:
+        $ref: /schemas/types.yaml#/definitions/string
+        pattern: "^[A-Za-z0-9]{4}$"
+        description: Writeable endpoint for setting desired fan speed
+
+      apple,fan-mode:
+        $ref: /schemas/types.yaml#/definitions/string
+        pattern: "^[A-Za-z0-9]{4}$"
+        description: Writeable key to enable/disable manual fan control
+
+      label:
+        $ref: "#/definitions/label"
+
+    required:
+      - apple,key-id
+      - label
+
+  "^power-[A-Za-z0-9]{4}$":
+    type: object
+    additionalProperties: false
+
+    properties:
+      apple,key-id:
+        $ref: "#/definitions/apple,key-id"
+
+      label:
+        $ref: "#/definitions/label"
+
+    required:
+      - apple,key-id
+      - label
+
+  "^temperature-[A-Za-z0-9]{4}$":
+    type: object
+    additionalProperties: false
+
+    properties:
+      apple,key-id:
+        $ref: "#/definitions/apple,key-id"
+
+      label:
+        $ref: "#/definitions/label"
+
+    required:
+      - apple,key-id
+      - label
+
+  "^voltage-[A-Za-z0-9]{4}$":
+    type: object
+    additionalProperties: false
+
+    properties:
+      apple,key-id:
+        $ref: "#/definitions/apple,key-id"
+
+      label:
+        $ref: "#/definitions/label"
+
+    required:
+      - apple,key-id
+      - label
+
+additionalProperties: false
diff --git a/Documentation/devicetree/bindings/mfd/apple,smc.yaml b/Documentation/devicetree/bindings/mfd/apple,smc.yaml
index 38f077867bdeedba8a486a63e366e9c943a75681..3fc4aa39292395f27b5694550858c6b34d18308d 100644
--- a/Documentation/devicetree/bindings/mfd/apple,smc.yaml
+++ b/Documentation/devicetree/bindings/mfd/apple,smc.yaml
@@ -44,6 +44,9 @@ properties:
   rtc:
     $ref: /schemas/rtc/apple,smc-rtc.yaml
 
+  hwmon:
+    $ref: /schemas/hwmon/apple,smc-hwmon.yaml
+
 additionalProperties: false
 
 required:
@@ -84,5 +87,38 @@ examples:
           nvmem-cells = <&rtc_offset>;
           nvmem-cell-names = "rtc_offset";
        };
+
+        hwmon {
+          compatible = "apple,smc-hwmon";
+
+          current-ID0R {
+            apple,key-id = "ID0R";
+            label = "AC Input Current";
+          };
+
+          fan-F0Ac {
+            apple,key-id = "F0Ac";
+            apple,fan-minimum = "F0Mn";
+            apple,fan-maximum = "F0Mx";
+            apple,fan-target = "F0Tg";
+            apple,fan-mode = "F0Md";
+            label = "Fan 1";
+          };
+
+          power-PSTR {
+            apple,key-id = "PSTR";
+            label = "Total System Power";
+          };
+
+          temperature-TW0P {
+            apple,key-id = "TW0P";
+            label = "WiFi/BT Module Temperature";
+          };
+
+          voltage-VD0R {
+            apple,key-id = "VD0R";
+            label = "AC Input Voltage";
+          };
+        };
       };
     };
diff --git a/MAINTAINERS b/MAINTAINERS
index aaef8634985b35f54de1123ebb4176602066d177..56aabfbc2520749beb9dba235f8e86c15e17b7b6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2380,6 +2380,7 @@ F:	Documentation/devicetree/bindings/cpufreq/apple,cluster-cpufreq.yaml
 F:	Documentation/devicetree/bindings/dma/apple,admac.yaml
 F:	Documentation/devicetree/bindings/gpio/apple,smc-gpio.yaml
 F:	Documentation/devicetree/bindings/gpu/apple,agx.yaml
+F:	Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
 F:	Documentation/devicetree/bindings/i2c/apple,i2c.yaml
 F:	Documentation/devicetree/bindings/input/touchscreen/apple,z2-multitouch.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/apple,*

-- 
2.51.0

[PATCH v2 03/11] rtc: Add new rtc-macsmc driver for Apple Silicon Macs

[James Calligeros]

From: Hector Martin <marcan@marcan.st>

Apple Silicon Macs (M1, etc.) have an RTC that is part of the PMU IC,
but most of the PMU functionality is abstracted out by the SMC.
On T600x machines, the RTC counter must be accessed via the SMC to
get full functionality, and it seems likely that future machines
will move towards making SMC handle all RTC functionality.

The SMC RTC counter access is implemented on all current machines
as of the time of this writing, on firmware 12.x. However, the RTC
offset (needed to set the time) is still only accessible via direct
PMU access. To handle this, we expose the RTC offset as an NVMEM
cell from the SPMI PMU device node, and this driver consumes that
cell and uses it to compute/set the current time.

Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Sven Peter <sven@kernel.org>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 MAINTAINERS              |   1 +
 drivers/rtc/Kconfig      |  11 ++
 drivers/rtc/Makefile     |   1 +
 drivers/rtc/rtc-macsmc.c | 141 +++++++++++++++++++++++++
 4 files changed, 154 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 56aabfbc2520749beb9dba235f8e86c15e17b7b6..5d53d243dc9abdf1db5865f8e6bcddbac3eafebe 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2422,6 +2422,7 @@ 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/rtc/rtc-macsmc.c
 F:	drivers/soc/apple/*
 F:	drivers/spi/spi-apple.c
 F:	drivers/spmi/spmi-apple-controller.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 64f6e9756aff4a1f6f6c50f9b4fc2140f66a8578..d28a46a89c85e6b30b402aec155e8972ed2aaa8e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -2068,6 +2068,17 @@ config RTC_DRV_WILCO_EC
 	  This can also be built as a module. If so, the module will
 	  be named "rtc_wilco_ec".
 
+config RTC_DRV_MACSMC
+	tristate "Apple Mac System Management Controller RTC"
+	depends on MFD_MACSMC
+	help
+	  If you say yes here you get support for RTC functions
+	  inside Apple SPMI PMUs accessed through the SoC's
+	  System Management Controller
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rtc-macsmc.
+
 config RTC_DRV_MSC313
 	tristate "MStar MSC313 RTC"
         depends on ARCH_MSTARV7 || COMPILE_TEST
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 789bddfea99d8fcd024566891c37ee73e527cf93..bcb43b5878a562454986cbb9ab8cc45cec248dda 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_RTC_DRV_M48T35)	+= rtc-m48t35.o
 obj-$(CONFIG_RTC_DRV_M48T59)	+= rtc-m48t59.o
 obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o
 obj-$(CONFIG_RTC_DRV_MA35D1)	+= rtc-ma35d1.o
+obj-$(CONFIG_RTC_DRV_MACSMC)	+= rtc-macsmc.o
 obj-$(CONFIG_RTC_DRV_MAX31335)	+= rtc-max31335.o
 obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
diff --git a/drivers/rtc/rtc-macsmc.c b/drivers/rtc/rtc-macsmc.c
new file mode 100644
index 0000000000000000000000000000000000000000..05e360277f630f3368b2856aadef1f2b96426c37
--- /dev/null
+++ b/drivers/rtc/rtc-macsmc.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SMC RTC driver
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/bitops.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/macsmc.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/slab.h>
+
+/* 48-bit RTC */
+#define RTC_BYTES 6
+#define RTC_BITS (8 * RTC_BYTES)
+
+/* 32768 Hz clock */
+#define RTC_SEC_SHIFT 15
+
+struct macsmc_rtc {
+	struct device *dev;
+	struct apple_smc *smc;
+	struct rtc_device *rtc_dev;
+	struct nvmem_cell *rtc_offset;
+};
+
+static int macsmc_rtc_get_time(struct device *dev, struct rtc_time *tm)
+{
+	struct macsmc_rtc *rtc = dev_get_drvdata(dev);
+	u64 ctr = 0, off = 0;
+	time64_t now;
+	void *p_off;
+	size_t len;
+	int ret;
+
+	ret = apple_smc_read(rtc->smc, SMC_KEY(CLKM), &ctr, RTC_BYTES);
+	if (ret < 0)
+		return ret;
+	if (ret != RTC_BYTES)
+		return -EIO;
+
+	p_off = nvmem_cell_read(rtc->rtc_offset, &len);
+	if (IS_ERR(p_off))
+		return PTR_ERR(p_off);
+	if (len < RTC_BYTES) {
+		kfree(p_off);
+		return -EIO;
+	}
+
+	memcpy(&off, p_off, RTC_BYTES);
+	kfree(p_off);
+
+	/* Sign extend from 48 to 64 bits, then arithmetic shift right 15 bits to get seconds */
+	now = sign_extend64(ctr + off, RTC_BITS - 1) >> RTC_SEC_SHIFT;
+	rtc_time64_to_tm(now, tm);
+
+	return ret;
+}
+
+static int macsmc_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct macsmc_rtc *rtc = dev_get_drvdata(dev);
+	u64 ctr = 0, off = 0;
+	int ret;
+
+	ret = apple_smc_read(rtc->smc, SMC_KEY(CLKM), &ctr, RTC_BYTES);
+	if (ret < 0)
+		return ret;
+	if (ret != RTC_BYTES)
+		return -EIO;
+
+	/* This sets the offset such that the set second begins now */
+	off = (rtc_tm_to_time64(tm) << RTC_SEC_SHIFT) - ctr;
+	return nvmem_cell_write(rtc->rtc_offset, &off, RTC_BYTES);
+}
+
+static const struct rtc_class_ops macsmc_rtc_ops = {
+	.read_time = macsmc_rtc_get_time,
+	.set_time = macsmc_rtc_set_time,
+};
+
+static int macsmc_rtc_probe(struct platform_device *pdev)
+{
+	struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
+	struct macsmc_rtc *rtc;
+
+	/*
+	 * MFD will probe this device even without a node in the device tree,
+	 * thus bail out early if the SMC on the current machines does not
+	 * support RTC and has no node in the device tree.
+	 */
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->dev = &pdev->dev;
+	rtc->smc = smc;
+
+	rtc->rtc_offset = devm_nvmem_cell_get(&pdev->dev, "rtc_offset");
+	if (IS_ERR(rtc->rtc_offset))
+		return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_offset),
+				     "Failed to get rtc_offset NVMEM cell\n");
+
+	rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(rtc->rtc_dev))
+		return PTR_ERR(rtc->rtc_dev);
+
+	rtc->rtc_dev->ops = &macsmc_rtc_ops;
+	rtc->rtc_dev->range_min = S64_MIN >> (RTC_SEC_SHIFT + (64 - RTC_BITS));
+	rtc->rtc_dev->range_max = S64_MAX >> (RTC_SEC_SHIFT + (64 - RTC_BITS));
+
+	platform_set_drvdata(pdev, rtc);
+
+	return devm_rtc_register_device(rtc->rtc_dev);
+}
+
+static const struct of_device_id macsmc_rtc_of_table[] = {
+	{ .compatible = "apple,smc-rtc", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, macsmc_rtc_of_table);
+
+static struct platform_driver macsmc_rtc_driver = {
+	.driver = {
+		.name = "macsmc-rtc",
+		.of_match_table = macsmc_rtc_of_table,
+	},
+	.probe = macsmc_rtc_probe,
+};
+module_platform_driver(macsmc_rtc_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_DESCRIPTION("Apple SMC RTC driver");
+MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");

-- 
2.51.0

[PATCH v2 04/11] mfd: macsmc: Wire up Apple SMC RTC subdevice

[James Calligeros]

Add the new SMC RTC function to the mfd device

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/mfd/macsmc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c
index 870c8b2028a8fc0e905c8934c2636824cbe5d527..59be894460d33afa754927630881532b548b7ad8 100644
--- a/drivers/mfd/macsmc.c
+++ b/drivers/mfd/macsmc.c
@@ -47,6 +47,7 @@
 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"),
+	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,

-- 
2.51.0

[PATCH v2 05/11] hwmon: Add Apple Silicon SMC hwmon driver

[James Calligeros]

The System Management Controller on Apple Silicon devices is responsible
for integrating and exposing the data reported by the vast array of
hardware monitoring sensors present on these devices. It is also
responsible for fan control, and allows users to manually set fan
speeds if they so desire. Add a hwmon driver to expose current,
power, temperature, and voltage monitoring sensors, as well as
fan speed monitoring and control via the SMC on Apple Silicon devices.

The SMC firmware has no consistency between devices, even when they
share an SoC. The FourCC keys used to access sensors are almost
random. An M1 Mac mini will have different FourCCs for its CPU core
temperature sensors to an M1 MacBook Pro, for example. For this
reason, the valid sensors for a given device are specified in a
child of the SMC Devicetree node. The driver uses this information
to determine which sensors to make available at runtime.

Co-developed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 MAINTAINERS                  |   1 +
 drivers/hwmon/Kconfig        |  12 +
 drivers/hwmon/Makefile       |   1 +
 drivers/hwmon/macsmc_hwmon.c | 848 +++++++++++++++++++++++++
 4 files changed, 862 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 5d53d243dc9abdf1db5865f8e6bcddbac3eafebe..2eb23522654dd050262eb06e077587030cc335aa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2408,6 +2408,7 @@ F:	drivers/clk/clk-apple-nco.c
 F:	drivers/cpufreq/apple-soc-cpufreq.c
 F:	drivers/dma/apple-admac.c
 F:	drivers/gpio/gpio-macsmc.c
+F:	drivers/hwmon/macsmc_hwmon.c
 F:	drivers/pmdomain/apple/
 F:	drivers/i2c/busses/i2c-pasemi-core.c
 F:	drivers/i2c/busses/i2c-pasemi-platform.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 9d28fcf7cd2a6f9e2f54694a717bd85ff4047b46..1ca6db71e4d9da32717fd14487c10944433ada41 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1164,6 +1164,18 @@ config SENSORS_LTQ_CPUTEMP
 	  If you say yes here you get support for the temperature
 	  sensor inside your CPU.
 
+config SENSORS_MACSMC_HWMON
+	tristate "Apple SMC (Apple Silicon)"
+	depends on MFD_MACSMC && OF
+	help
+	  This driver enables hwmon support for current, power, temperature,
+	  and voltage sensors, as well as fan speed reporting and control
+	  on Apple Silicon devices. Say Y here if you have an Apple Silicon
+	  device.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called macsmc_hwmon.
+
 config SENSORS_MAX1111
 	tristate "Maxim MAX1111 Serial 8-bit ADC chip and compatibles"
 	depends on SPI_MASTER
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index cd8bc4752b4dbf015c6eb46157626f4e8f87dfae..80fc8447aff15b3b8e8583dc755c8accb3b6a93e 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_LTC4260)	+= ltc4260.o
 obj-$(CONFIG_SENSORS_LTC4261)	+= ltc4261.o
 obj-$(CONFIG_SENSORS_LTC4282)	+= ltc4282.o
 obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
+obj-$(CONFIG_SENSORS_MACSMC_HWMON)	+= macsmc_hwmon.o
 obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o
 obj-$(CONFIG_SENSORS_MAX127)	+= max127.o
 obj-$(CONFIG_SENSORS_MAX16065)	+= max16065.o
diff --git a/drivers/hwmon/macsmc_hwmon.c b/drivers/hwmon/macsmc_hwmon.c
new file mode 100644
index 0000000000000000000000000000000000000000..e44ea357870238aa0b38d7b674a6c456271fdf0c
--- /dev/null
+++ b/drivers/hwmon/macsmc_hwmon.c
@@ -0,0 +1,848 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SMC hwmon driver for Apple Silicon platforms
+ *
+ * The System Management Controller on Apple Silicon devices is responsible for
+ * measuring data from sensors across the SoC and machine. These include power,
+ * temperature, voltage and current sensors. Some "sensors" actually expose
+ * derived values. An example of this is the key PHPC, which is an estimate
+ * of the heat energy being dissipated by the SoC.
+ *
+ * While each SoC only has one SMC variant, each platform exposes a different
+ * set of sensors. For example, M1 MacBooks expose battery telemetry sensors
+ * which are not present on the M1 Mac mini. For this reason, the available
+ * sensors for a given platform are described in the device tree in a child
+ * node of the SMC device. We must walk this list of available sensors and
+ * populate the required hwmon data structures at runtime.
+ *
+ * Originally based on a concept by Jean-Francois Bortolotti <jeff@borto.fr>
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/mfd/macsmc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#define MAX_LABEL_LENGTH	32
+#define NUM_SENSOR_TYPES	5 /* temp, volt, current, power, fan */
+
+#define FLT_EXP_BIAS	127
+#define FLT_EXP_MASK	GENMASK(30, 23)
+#define FLT_MANT_BIAS	23
+#define FLT_MANT_MASK	GENMASK(22, 0)
+#define FLT_SIGN_MASK	BIT(31)
+
+static bool fan_control;
+module_param_unsafe(fan_control, bool, 0644);
+MODULE_PARM_DESC(fan_control,
+		 "Override the SMC to set your own fan speeds on supported machines");
+
+struct macsmc_hwmon_sensor {
+	struct apple_smc_key_info info;
+	smc_key macsmc_key;
+	char label[MAX_LABEL_LENGTH];
+};
+
+struct macsmc_hwmon_fan {
+	struct macsmc_hwmon_sensor now;
+	struct macsmc_hwmon_sensor min;
+	struct macsmc_hwmon_sensor max;
+	struct macsmc_hwmon_sensor set;
+	struct macsmc_hwmon_sensor mode;
+	char label[MAX_LABEL_LENGTH];
+	u32 attrs;
+	bool manual;
+};
+
+struct macsmc_hwmon_sensors {
+	struct hwmon_channel_info channel_info;
+	struct macsmc_hwmon_sensor *sensors;
+	u32 count;
+};
+
+struct macsmc_hwmon_fans {
+	struct hwmon_channel_info channel_info;
+	struct macsmc_hwmon_fan *fans;
+	u32 count;
+};
+
+struct macsmc_hwmon {
+	struct device *dev;
+	struct apple_smc *smc;
+	struct device *hwmon_dev;
+	struct hwmon_chip_info chip_info;
+	/* Chip + sensor types + NULL */
+	const struct hwmon_channel_info *channel_infos[1 + NUM_SENSOR_TYPES + 1];
+	struct macsmc_hwmon_sensors temp;
+	struct macsmc_hwmon_sensors volt;
+	struct macsmc_hwmon_sensors curr;
+	struct macsmc_hwmon_sensors power;
+	struct macsmc_hwmon_fans fan;
+};
+
+static int macsmc_hwmon_read_label(struct device *dev,
+				   enum hwmon_sensor_types type, u32 attr,
+				   int channel, const char **str)
+{
+	struct macsmc_hwmon *hwmon = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_temp:
+		if (channel >= hwmon->temp.count)
+			return -EINVAL;
+		*str = hwmon->temp.sensors[channel].label;
+		break;
+	case hwmon_in:
+		if (channel >= hwmon->volt.count)
+			return -EINVAL;
+		*str = hwmon->volt.sensors[channel].label;
+		break;
+	case hwmon_curr:
+		if (channel >= hwmon->curr.count)
+			return -EINVAL;
+		*str = hwmon->curr.sensors[channel].label;
+		break;
+	case hwmon_power:
+		if (channel >= hwmon->power.count)
+			return -EINVAL;
+		*str = hwmon->power.sensors[channel].label;
+		break;
+	case hwmon_fan:
+		if (channel >= hwmon->fan.count)
+			return -EINVAL;
+		*str = hwmon->fan.fans[channel].label;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+/*
+ * A number of sensors report data in a 48.16 fixed-point decimal format that is
+ * not used by any other function of the SMC.
+ */
+static int macsmc_hwmon_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;
+
+	*p = mult_frac(val, scale, 65536);
+
+	return 0;
+}
+
+/*
+ * Many sensors report their data as IEEE-754 floats. No other SMC function uses
+ * them.
+ */
+static int macsmc_hwmon_read_f32_scaled(struct apple_smc *smc, smc_key key,
+					int *p, int scale)
+{
+	u32 fval;
+	u64 val;
+	int ret, exp;
+
+	ret = apple_smc_read_u32(smc, key, &fval);
+	if (ret < 0)
+		return ret;
+
+	val = ((u64)((fval & FLT_MANT_MASK) | BIT(23)));
+	exp = ((fval >> 23) & 0xff) - FLT_EXP_BIAS - FLT_MANT_BIAS;
+	if (scale < 0) {
+		val <<= 32;
+		exp -= 32;
+		val /= -scale;
+	} else {
+		val *= scale;
+	}
+
+	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;
+
+	if (fval & FLT_SIGN_MASK) {
+		if (val > (-(s64)INT_MIN))
+			*p = INT_MIN;
+		else
+			*p = -val;
+	} else {
+		if (val > INT_MAX)
+			*p = INT_MAX;
+		else
+			*p = val;
+	}
+
+	return 0;
+}
+
+/*
+ * The SMC has keys of multiple types, denoted by a FourCC of the same format
+ * as the key ID. We don't know what data type a key encodes until we poke at it.
+ */
+static int macsmc_hwmon_read_key(struct apple_smc *smc,
+				 struct macsmc_hwmon_sensor *sensor, int scale,
+				 long *val)
+{
+	int ret;
+
+	switch (sensor->info.type_code) {
+	/* 32-bit IEEE 754 float */
+	case _SMC_KEY("flt "): {
+		u32 flt_ = 0;
+
+		ret = macsmc_hwmon_read_f32_scaled(smc, sensor->macsmc_key,
+						   &flt_, scale);
+		*val = flt_;
+		break;
+	}
+	/* 48.16 fixed point decimal */
+	case _SMC_KEY("ioft"): {
+		u64 ioft = 0;
+
+		ret = macsmc_hwmon_read_ioft_scaled(smc, sensor->macsmc_key,
+						    &ioft, scale);
+		*val = (long)ioft;
+		break;
+	}
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	if (ret)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int macsmc_hwmon_write_f32_scaled(struct apple_smc *smc, smc_key key,
+					 int value, int scale)
+{
+	u64 val;
+	u32 fval = 0;
+	int exp, neg;
+
+	val = abs(value);
+	neg = val != value;
+
+	if (scale > 1) {
+		val <<= 32;
+		exp = 32;
+		val /= scale;
+	} else if (scale < 1) {
+		val *= -scale;
+	}
+
+	if (val) {
+		int msb = __fls(val) - exp;
+
+		if (msb > 23) {
+			val >>= msb - 23;
+			exp -= msb - 23;
+		} else if (msb < 23) {
+			val <<= 23 - msb;
+			exp += msb;
+		}
+
+		fval = FIELD_PREP(FLT_SIGN_MASK, neg) |
+		       FIELD_PREP(FLT_EXP_MASK, exp + FLT_EXP_BIAS) |
+		       FIELD_PREP(FLT_MANT_MASK, val);
+	}
+
+	return apple_smc_write_u32(smc, key, fval);
+}
+
+static int macsmc_hwmon_write_key(struct apple_smc *smc,
+				  struct macsmc_hwmon_sensor *sensor, long val,
+				  int scale)
+{
+	switch (sensor->info.type_code) {
+	/* 32-bit IEEE 754 float */
+	case _SMC_KEY("flt "):
+		return macsmc_hwmon_write_f32_scaled(smc, sensor->macsmc_key,
+						     val, scale);
+	/* unsigned 8-bit integer */
+	case _SMC_KEY("ui8 "):
+		return apple_smc_write_u8(smc, sensor->macsmc_key, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int macsmc_hwmon_read_fan(struct macsmc_hwmon *hwmon, u32 attr, int chan,
+				 long *val)
+{
+	if (!(hwmon->fan.fans[chan].attrs & BIT(attr)))
+		return -EINVAL;
+
+	switch (attr) {
+	case hwmon_fan_input:
+		return macsmc_hwmon_read_key(hwmon->smc,
+					     &hwmon->fan.fans[chan].now, 1, val);
+	case hwmon_fan_min:
+		return macsmc_hwmon_read_key(hwmon->smc,
+					     &hwmon->fan.fans[chan].min, 1, val);
+	case hwmon_fan_max:
+		return macsmc_hwmon_read_key(hwmon->smc,
+					     &hwmon->fan.fans[chan].max, 1, val);
+	case hwmon_fan_target:
+		return macsmc_hwmon_read_key(hwmon->smc,
+					     &hwmon->fan.fans[chan].set, 1, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int macsmc_hwmon_write_fan(struct device *dev, u32 attr, int channel,
+				  long val)
+{
+	struct macsmc_hwmon *hwmon = dev_get_drvdata(dev);
+	long min, max;
+	int ret;
+
+	if (!fan_control || hwmon->fan.fans[channel].mode.macsmc_key == 0)
+		return -EOPNOTSUPP;
+
+	if (channel >= hwmon->fan.count ||
+	    !(hwmon->fan.fans[channel].attrs & BIT(attr)) ||
+	    attr != hwmon_fan_target)
+		return -EINVAL;
+
+	/*
+	 * The SMC does no sanity checks on requested fan speeds, so we need to.
+	 */
+	ret = macsmc_hwmon_read_key(hwmon->smc, &hwmon->fan.fans[channel].min,
+				    1, &min);
+	if (ret)
+		return ret;
+
+	ret = macsmc_hwmon_read_key(hwmon->smc, &hwmon->fan.fans[channel].max,
+				    1, &max);
+	if (ret)
+		return ret;
+
+	if (val >= min && val <= max) {
+		if (!hwmon->fan.fans[channel].manual) {
+			/* Write 1 to mode key for manual control */
+			ret = macsmc_hwmon_write_key(hwmon->smc,
+						     &hwmon->fan.fans[channel].mode, 1,
+						     1);
+			if (ret < 0)
+				return ret;
+
+			hwmon->fan.fans[channel].manual = true;
+		}
+		return macsmc_hwmon_write_key(hwmon->smc,
+					      &hwmon->fan.fans[channel].set, val, 1);
+	} else if (!val) {
+		if (hwmon->fan.fans[channel].manual) {
+			ret = macsmc_hwmon_write_key(hwmon->smc,
+						     &hwmon->fan.fans[channel].mode, 0, 1);
+			if (ret < 0)
+				return ret;
+
+			hwmon->fan.fans[channel].manual = false;
+		}
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int macsmc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+			     u32 attr, int channel, long *val)
+{
+	struct macsmc_hwmon *hwmon = dev_get_drvdata(dev);
+	int ret = 0;
+
+	switch (type) {
+	case hwmon_temp:
+		ret = macsmc_hwmon_read_key(hwmon->smc,
+					    &hwmon->temp.sensors[channel], 1000, val);
+		break;
+	case hwmon_in:
+		ret = macsmc_hwmon_read_key(hwmon->smc,
+					    &hwmon->volt.sensors[channel], 1000, val);
+		break;
+	case hwmon_curr:
+		ret = macsmc_hwmon_read_key(hwmon->smc,
+					    &hwmon->curr.sensors[channel], 1000, val);
+		break;
+	case hwmon_power:
+		/* SMC returns power in Watts with acceptable precision to scale to uW */
+		ret = macsmc_hwmon_read_key(hwmon->smc,
+					    &hwmon->power.sensors[channel],
+					    1000000, val);
+		break;
+	case hwmon_fan:
+		ret = macsmc_hwmon_read_fan(hwmon, attr, channel, val);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return ret;
+}
+
+static int macsmc_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
+			      u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_fan:
+		return macsmc_hwmon_write_fan(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t macsmc_hwmon_fan_is_visible(const void *data, u32 attr,
+					   int channel)
+{
+	const struct macsmc_hwmon *hwmon = data;
+
+	if (fan_control && attr == hwmon_fan_target &&
+	    hwmon->fan.fans[channel].mode.macsmc_key != 0)
+		return 0644;
+
+	return 0444;
+}
+
+static umode_t macsmc_hwmon_is_visible(const void *data,
+				       enum hwmon_sensor_types type, u32 attr,
+				       int channel)
+{
+	switch (type) {
+	case hwmon_fan:
+		return macsmc_hwmon_fan_is_visible(data, attr, channel);
+	default:
+		break;
+	}
+
+	return 0444;
+}
+
+static const struct hwmon_ops macsmc_hwmon_ops = {
+	.is_visible = macsmc_hwmon_is_visible,
+	.read = macsmc_hwmon_read,
+	.read_string = macsmc_hwmon_read_label,
+	.write = macsmc_hwmon_write,
+};
+
+/*
+ * Get the key metadata, including key data type, from the SMC.
+ */
+static int macsmc_hwmon_parse_key(struct device *dev, struct apple_smc *smc,
+				  struct macsmc_hwmon_sensor *sensor,
+				  const char *key)
+{
+	int ret;
+
+	ret = apple_smc_get_key_info(smc, _SMC_KEY(key), &sensor->info);
+	if (ret) {
+		dev_err(dev, "Failed to retrieve key info for %s\n", key);
+		return ret;
+	}
+
+	sensor->macsmc_key = _SMC_KEY(key);
+
+	return 0;
+}
+
+/*
+ * A sensor is a single key-value pair as made available by the SMC.
+ * The devicetree gives us the SMC key ID and a friendly name where the
+ * purpose of the sensor is known.
+ */
+static int macsmc_hwmon_create_sensor(struct device *dev, struct apple_smc *smc,
+				      struct device_node *sensor_node,
+				      struct macsmc_hwmon_sensor *sensor)
+{
+	const char *key, *label;
+	int ret;
+
+	ret = of_property_read_string(sensor_node, "apple,key-id", &key);
+	if (ret) {
+		dev_err(dev, "Could not find apple,key-id in sensor node\n");
+		return ret;
+	}
+
+	ret = macsmc_hwmon_parse_key(dev, smc, sensor, key);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_string(sensor_node, "label", &label);
+	if (ret) {
+		dev_err(dev, "No label found for sensor %s\n", key);
+		return ret;
+	}
+
+	strscpy_pad(sensor->label, label, sizeof(sensor->label));
+
+	return 0;
+}
+
+/*
+ * Fan data is exposed by the SMC as multiple sensors.
+ *
+ * The devicetree schema reuses apple,key-id for the actual fan speed sensor.
+ * Min, max and target keys do not need labels, so we can reuse label
+ * for naming the entire fan.
+ */
+static int macsmc_hwmon_create_fan(struct device *dev, struct apple_smc *smc,
+				   struct device_node *fan_node,
+				   struct macsmc_hwmon_fan *fan)
+{
+	const char *label, *now, *min, *max, *set, *mode;
+	int ret;
+
+	ret = of_property_read_string(fan_node, "apple,key-id", &now);
+	if (ret) {
+		dev_err(dev, "apple,key-id not found in fan node!\n");
+		return -EINVAL;
+	}
+
+	ret = macsmc_hwmon_parse_key(dev, smc, &fan->now, now);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_string(fan_node, "label", &label);
+	if (ret) {
+		dev_err(dev, "No label found for fan %s\n", now);
+		return ret;
+	}
+
+	strscpy_pad(fan->label, label, sizeof(fan->label));
+
+	fan->attrs = HWMON_F_LABEL | HWMON_F_INPUT;
+
+	/* The following keys are not required to simply monitor fan speed */
+	if (!of_property_read_string(fan_node, "apple,fan-minimum", &min)) {
+		ret = macsmc_hwmon_parse_key(dev, smc, &fan->min, min);
+		if (ret)
+			return ret;
+
+		fan->attrs |= HWMON_F_MIN;
+	}
+
+	if (!of_property_read_string(fan_node, "apple,fan-maximum", &max)) {
+		ret = macsmc_hwmon_parse_key(dev, smc, &fan->max, max);
+		if (ret)
+			return ret;
+
+		fan->attrs |= HWMON_F_MAX;
+	}
+
+	if (!of_property_read_string(fan_node, "apple,fan-target", &set)) {
+		ret = macsmc_hwmon_parse_key(dev, smc, &fan->set, set);
+		if (ret)
+			return ret;
+
+		fan->attrs |= HWMON_F_TARGET;
+	}
+
+	if (!of_property_read_string(fan_node, "apple,fan-mode", &mode)) {
+		ret = macsmc_hwmon_parse_key(dev, smc, &fan->mode, mode);
+		if (ret)
+			return ret;
+	}
+
+	/* Initialise fan control mode to automatic */
+	fan->manual = false;
+
+	return 0;
+}
+
+static int macsmc_hwmon_populate_sensors(struct macsmc_hwmon *hwmon,
+					 struct device_node *hwmon_node)
+{
+	struct device_node *key_node __maybe_unused;
+	u32 n_current = 0, n_fan = 0, n_power = 0, n_temperature = 0, n_voltage = 0;
+
+	for_each_child_of_node_with_prefix(hwmon_node, key_node, "current-") {
+		n_current++;
+	}
+
+	if (n_current) {
+		hwmon->curr.sensors = devm_kcalloc(hwmon->dev, n_current,
+						   sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
+		if (!hwmon->curr.sensors)
+			return -ENOMEM;
+
+		for_each_child_of_node_with_prefix(hwmon_node, key_node, "current-") {
+			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
+							&hwmon->curr.sensors[hwmon->curr.count]))
+				hwmon->curr.count++;
+		}
+	}
+
+	for_each_child_of_node_with_prefix(hwmon_node, key_node, "fan-") {
+		n_fan++;
+	}
+
+	if (n_fan) {
+		hwmon->fan.fans = devm_kcalloc(hwmon->dev, n_fan,
+					       sizeof(struct macsmc_hwmon_fan), GFP_KERNEL);
+		if (!hwmon->fan.fans)
+			return -ENOMEM;
+
+		for_each_child_of_node_with_prefix(hwmon_node, key_node, "fan-") {
+			if (!macsmc_hwmon_create_fan(hwmon->dev, hwmon->smc, key_node,
+						     &hwmon->fan.fans[hwmon->fan.count]))
+				hwmon->fan.count++;
+		}
+	}
+
+	for_each_child_of_node_with_prefix(hwmon_node, key_node, "power-") {
+		n_power++;
+	}
+
+	if (n_power) {
+		hwmon->power.sensors = devm_kcalloc(hwmon->dev, n_power,
+						    sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
+		if (!hwmon->power.sensors)
+			return -ENOMEM;
+
+		for_each_child_of_node_with_prefix(hwmon_node, key_node, "power-") {
+			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
+							&hwmon->power.sensors[hwmon->power.count]))
+				hwmon->power.count++;
+		}
+	}
+
+	for_each_child_of_node_with_prefix(hwmon_node, key_node, "temperature-") {
+		n_temperature++;
+	}
+
+	if (n_temperature) {
+		hwmon->temp.sensors = devm_kcalloc(hwmon->dev, n_temperature,
+						   sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
+		if (!hwmon->temp.sensors)
+			return -ENOMEM;
+
+		for_each_child_of_node_with_prefix(hwmon_node, key_node, "temperature-") {
+			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
+							&hwmon->temp.sensors[hwmon->temp.count]))
+				hwmon->temp.count++;
+		}
+	}
+
+	for_each_child_of_node_with_prefix(hwmon_node, key_node, "voltage-") {
+		n_voltage++;
+	}
+
+	if (n_voltage) {
+		hwmon->volt.sensors = devm_kcalloc(hwmon->dev, n_voltage,
+						   sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
+		if (!hwmon->volt.sensors)
+			return -ENOMEM;
+
+		for_each_child_of_node_with_prefix(hwmon_node, key_node, "volt-") {
+			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
+							&hwmon->volt.sensors[hwmon->volt.count]))
+				hwmon->volt.count++;
+		}
+	}
+
+	return 0;
+}
+
+/* Create NULL-terminated config arrays */
+static void macsmc_hwmon_populate_configs(u32 *configs, u32 num_keys, u32 flags)
+{
+	int idx;
+
+	for (idx = 0; idx < num_keys; idx++)
+		configs[idx] = flags;
+}
+
+static void macsmc_hwmon_populate_fan_configs(u32 *configs, u32 num_keys,
+					      struct macsmc_hwmon_fans *fans)
+{
+	int idx;
+
+	for (idx = 0; idx < num_keys; idx++)
+		configs[idx] = fans->fans[idx].attrs;
+}
+
+static const struct hwmon_channel_info *const macsmc_chip_channel_info =
+	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ);
+
+static int macsmc_hwmon_create_infos(struct macsmc_hwmon *hwmon)
+{
+	struct hwmon_channel_info *channel_info;
+	int i = 0;
+
+	/* chip */
+	hwmon->channel_infos[i++] = macsmc_chip_channel_info;
+
+	if (hwmon->curr.count) {
+		channel_info = &hwmon->curr.channel_info;
+		channel_info->type = hwmon_curr;
+		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->curr.count + 1,
+						    sizeof(u32), GFP_KERNEL);
+		if (!channel_info->config)
+			return -ENOMEM;
+
+		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
+					      hwmon->curr.count,
+					      (HWMON_C_INPUT | HWMON_C_LABEL));
+		hwmon->channel_infos[i++] = channel_info;
+	}
+
+	if (hwmon->fan.count) {
+		channel_info = &hwmon->fan.channel_info;
+		channel_info->type = hwmon_fan;
+		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->fan.count + 1,
+						    sizeof(u32), GFP_KERNEL);
+		if (!channel_info->config)
+			return -ENOMEM;
+
+		macsmc_hwmon_populate_fan_configs((u32 *)channel_info->config,
+						  hwmon->fan.count,
+						  &hwmon->fan);
+		hwmon->channel_infos[i++] = channel_info;
+	}
+
+	if (hwmon->power.count) {
+		channel_info = &hwmon->power.channel_info;
+		channel_info->type = hwmon_power;
+		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->power.count + 1,
+						    sizeof(u32), GFP_KERNEL);
+		if (!channel_info->config)
+			return -ENOMEM;
+
+		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
+					      hwmon->power.count,
+					      (HWMON_P_INPUT | HWMON_P_LABEL));
+		hwmon->channel_infos[i++] = channel_info;
+	}
+
+	if (hwmon->temp.count) {
+		channel_info = &hwmon->temp.channel_info;
+		channel_info->type = hwmon_temp;
+		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->temp.count + 1,
+						    sizeof(u32), GFP_KERNEL);
+		if (!channel_info->config)
+			return -ENOMEM;
+
+		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
+					      hwmon->temp.count,
+					      (HWMON_T_INPUT | HWMON_T_LABEL));
+		hwmon->channel_infos[i++] = channel_info;
+	}
+
+	if (hwmon->volt.count) {
+		channel_info = &hwmon->volt.channel_info;
+		channel_info->type = hwmon_in;
+		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->volt.count + 1,
+						    sizeof(u32), GFP_KERNEL);
+		if (!channel_info->config)
+			return -ENOMEM;
+
+		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
+					      hwmon->volt.count,
+					      (HWMON_I_INPUT | HWMON_I_LABEL));
+		hwmon->channel_infos[i++] = channel_info;
+	}
+
+	return 0;
+}
+
+static int macsmc_hwmon_probe(struct platform_device *pdev)
+{
+	struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
+	struct macsmc_hwmon *hwmon;
+	int ret;
+
+	/*
+	 * The MFD driver will try to probe us unconditionally. Some devices
+	 * with the SMC do not have hwmon capabilities. Only probe if we have
+	 * a hwmon node.
+	 */
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon),
+			     GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	hwmon->dev = &pdev->dev;
+	hwmon->smc = smc;
+
+	ret = macsmc_hwmon_populate_sensors(hwmon, hwmon->dev->of_node);
+	if (ret) {
+		dev_err(hwmon->dev, "Could not populate keys!\n");
+		return ret;
+	}
+
+	if (!hwmon->curr.count && !hwmon->fan.count &&
+	    !hwmon->power.count && !hwmon->temp.count &&
+	    !hwmon->volt.count) {
+		dev_err(hwmon->dev,
+			"No valid keys found of any supported type");
+		return -ENODEV;
+	}
+
+	ret = macsmc_hwmon_create_infos(hwmon);
+	if (ret)
+		return ret;
+
+	hwmon->chip_info.ops = &macsmc_hwmon_ops;
+	hwmon->chip_info.info =
+		(const struct hwmon_channel_info *const *)&hwmon->channel_infos;
+
+	hwmon->hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
+								"macsmc_hwmon", hwmon,
+								&hwmon->chip_info, NULL);
+	if (IS_ERR(hwmon->hwmon_dev))
+		return dev_err_probe(hwmon->dev, PTR_ERR(hwmon->hwmon_dev),
+				     "Probing SMC hwmon device failed\n");
+
+	dev_info(hwmon->dev, "Registered SMC hwmon device. Sensors:");
+	dev_info(hwmon->dev,
+		 "Current: %d, Fans: %d, Power: %d, Temperature: %d, Voltage: %d",
+		 hwmon->curr.count, hwmon->fan.count,
+		 hwmon->power.count, hwmon->temp.count,
+		 hwmon->volt.count);
+
+	return 0;
+}
+
+static const struct of_device_id macsmc_hwmon_of_table[] = {
+	{ .compatible = "apple,smc-hwmon" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, macsmc_hwmon_of_table);
+
+static struct platform_driver macsmc_hwmon_driver = {
+	.probe = macsmc_hwmon_probe,
+	.driver = {
+		.name = "macsmc_hwmon",
+		.of_match_table = macsmc_hwmon_of_table,
+	},
+};
+module_platform_driver(macsmc_hwmon_driver);
+
+MODULE_DESCRIPTION("Apple Silicon SMC hwmon driver");
+MODULE_AUTHOR("James Calligeros <jcalligeros99@gmail.com>");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_ALIAS("platform:macsmc_hwmon");

-- 
2.51.0

[PATCH v2 06/11] mfd: macsmc: Wire up Apple SMC hwmon subdevice

[James Calligeros]

Add the SMC hwmon functionality to the mfd device

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/mfd/macsmc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c
index 59be894460d33afa754927630881532b548b7ad8..286dc150aa6cfdd6d29f769094278daaddabe7c3 100644
--- a/drivers/mfd/macsmc.c
+++ b/drivers/mfd/macsmc.c
@@ -46,6 +46,7 @@
 
 static const struct mfd_cell apple_smc_devs[] = {
 	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"),
 };

-- 
2.51.0

[PATCH v2 07/11] input: macsmc-hid: New driver to handle the Apple Mac SMC buttons/lid

[James Calligeros]

From: Hector Martin <marcan@marcan.st>

This driver implements power button and lid switch support for Apple Mac
devices using SMC controllers driven by the macsmc driver.

In addition to basic input support, this also responds to the final
shutdown warning (when the power button is held down long enough) by
doing an emergency kernel poweroff. This allows the NVMe controller to
be cleanly shut down, which prevents data loss for in-cache data.

Signed-off-by: Hector Martin <marcan@marcan.st>
Co-developed-by: Sven Peter <sven@kernel.org>
Signed-off-by: Sven Peter <sven@kernel.org>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 MAINTAINERS                     |   1 +
 drivers/input/misc/Kconfig      |  11 ++
 drivers/input/misc/Makefile     |   1 +
 drivers/input/misc/macsmc-hid.c | 209 +++++++++++++++++++++++++
 4 files changed, 222 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 2eb23522654dd050262eb06e077587030cc335aa..b3b5220fcd0d4bbef67613c8ee9afa880c0aa45d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2412,6 +2412,7 @@ F:	drivers/hwmon/macsmc_hwmon.c
 F:	drivers/pmdomain/apple/
 F:	drivers/i2c/busses/i2c-pasemi-core.c
 F:	drivers/i2c/busses/i2c-pasemi-platform.c
+F:	drivers/input/misc/macsmc-hid.c
 F:	drivers/input/touchscreen/apple_z2.c
 F:	drivers/iommu/apple-dart.c
 F:	drivers/iommu/io-pgtable-dart.c
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 0fb21c99a5e3d1230d7f40f99e0c2d360bbe80e8..a430c50e7f63f245bba56bd526026ec7901cf821 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -961,4 +961,15 @@ config INPUT_STPMIC1_ONKEY
 	  To compile this driver as a module, choose M here: the
 	  module will be called stpmic1_onkey.
 
+config INPUT_MACSMC_HID
+	tristate "Apple Mac SMC lid/buttons"
+	depends on MFD_MACSMC
+	help
+	  Say Y here if you want to use the input events delivered via the
+	  SMC controller on Apple Mac machines using the macsmc driver.
+	  This includes lid open/close and the power button.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called macsmc-hid.
+
 endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index d468c8140b93da5bb537e8a3baea2b90e7bb4229..95b8ebbb9ebbe6f3afc9db724d2ebeba1d75d1a6 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_INPUT_IQS7222)		+= iqs7222.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
+obj-$(CONFIG_INPUT_MACSMC_HID)		+= macsmc-hid.o
 obj-$(CONFIG_INPUT_MAX77650_ONKEY)	+= max77650-onkey.o
 obj-$(CONFIG_INPUT_MAX77693_HAPTIC)	+= max77693-haptic.o
 obj-$(CONFIG_INPUT_MAX8925_ONKEY)	+= max8925_onkey.o
diff --git a/drivers/input/misc/macsmc-hid.c b/drivers/input/misc/macsmc-hid.c
new file mode 100644
index 0000000000000000000000000000000000000000..c7cd56e5c17f08936cc623f7d3690f27e05012a5
--- /dev/null
+++ b/drivers/input/misc/macsmc-hid.c
@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SMC input event driver
+ * Copyright The Asahi Linux Contributors
+ *
+ * This driver exposes HID events from the SMC as an input device.
+ * This includes the lid open/close and power button notifications.
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/macsmc.h>
+#include <linux/module.h>
+#include <linux/reboot.h>
+
+/**
+ * struct macsmc_hid
+ * @dev: Underlying struct device for the HID sub-device
+ * @smc: Pointer to apple_smc struct of the mfd parent
+ * @input: Allocated input_dev; devres managed
+ * @nb: Notifier block used for incoming events from SMC (e.g. button pressed down)
+ * @wakeup_mode: Set to true when system is suspended and power button events should wake it
+ */
+struct macsmc_hid {
+	struct device *dev;
+	struct apple_smc *smc;
+	struct input_dev *input;
+	struct notifier_block nb;
+	bool wakeup_mode;
+};
+
+#define SMC_EV_BTN 0x7201
+#define SMC_EV_LID 0x7203
+
+#define BTN_POWER		0x01 /* power button on e.g. Mac Mini chasis pressed */
+#define BTN_TOUCHID		0x06 /* combined TouchID / power button on MacBooks pressed */
+#define BTN_POWER_HELD_SHORT	0xfe /* power button briefly held down */
+#define BTN_POWER_HELD_LONG	0x00 /* power button held down; sent just before forced poweroff */
+
+static void macsmc_hid_event_button(struct macsmc_hid *smchid, unsigned long event)
+{
+	u8 button = (event >> 8) & 0xff;
+	u8 state = !!(event & 0xff);
+
+	switch (button) {
+	case BTN_POWER:
+	case BTN_TOUCHID:
+		if (smchid->wakeup_mode) {
+			if (state)
+				pm_wakeup_hard_event(smchid->dev);
+		} else {
+			input_report_key(smchid->input, KEY_POWER, state);
+			input_sync(smchid->input);
+		}
+		break;
+	case BTN_POWER_HELD_SHORT: /* power button held down; ignore */
+		break;
+	case BTN_POWER_HELD_LONG:
+		/*
+		 * If we get here the power button has been held down for a while and
+		 * we have about 4 seconds before forced power-off is triggered by SMC.
+		 * Try to do an emergency shutdown to make sure the NVMe cache is
+		 * flushed. macOS actually does this by panicing (!)...
+		 */
+		if (state) {
+			dev_crit(smchid->dev, "Triggering forced shutdown!\n");
+			if (kernel_can_power_off())
+				kernel_power_off();
+			else /* Missing macsmc-reboot driver? */
+				kernel_restart("SMC power button triggered restart");
+		}
+		break;
+	default:
+		dev_warn(smchid->dev, "Unknown SMC button event: %04lx\n", event & 0xffff);
+	}
+}
+
+static void macsmc_hid_event_lid(struct macsmc_hid *smchid, unsigned long event)
+{
+	u8 lid_state = !!((event >> 8) & 0xff);
+
+	if (smchid->wakeup_mode && !lid_state)
+		pm_wakeup_hard_event(smchid->dev);
+
+	input_report_switch(smchid->input, SW_LID, lid_state);
+	input_sync(smchid->input);
+}
+
+static int macsmc_hid_event(struct notifier_block *nb, unsigned long event, void *data)
+{
+	struct macsmc_hid *smchid = container_of(nb, struct macsmc_hid, nb);
+	u16 type = event >> 16;
+
+	switch (type) {
+	case SMC_EV_BTN:
+		macsmc_hid_event_button(smchid, event);
+		return NOTIFY_OK;
+	case SMC_EV_LID:
+		macsmc_hid_event_lid(smchid, event);
+		return NOTIFY_OK;
+	default:
+		/* SMC event meant for another driver */
+		return NOTIFY_DONE;
+	}
+}
+
+static int macsmc_hid_probe(struct platform_device *pdev)
+{
+	struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
+	struct macsmc_hid *smchid;
+	bool have_lid, have_power;
+	int ret;
+
+	/* Bail early if this SMC neither supports power button nor lid events */
+	have_lid = apple_smc_key_exists(smc, SMC_KEY(MSLD));
+	have_power = apple_smc_key_exists(smc, SMC_KEY(bHLD));
+	if (!have_lid && !have_power)
+		return -ENODEV;
+
+	smchid = devm_kzalloc(&pdev->dev, sizeof(*smchid), GFP_KERNEL);
+	if (!smchid)
+		return -ENOMEM;
+
+	smchid->dev = &pdev->dev;
+	smchid->smc = smc;
+	platform_set_drvdata(pdev, smchid);
+
+	smchid->input = devm_input_allocate_device(&pdev->dev);
+	if (!smchid->input)
+		return -ENOMEM;
+
+	smchid->input->phys = "macsmc-hid (0)";
+	smchid->input->name = "Apple SMC power/lid events";
+
+	if (have_lid)
+		input_set_capability(smchid->input, EV_SW, SW_LID);
+	if (have_power)
+		input_set_capability(smchid->input, EV_KEY, KEY_POWER);
+
+	ret = input_register_device(smchid->input);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register input device: %d\n", ret);
+		return ret;
+	}
+
+	if (have_lid) {
+		u8 val;
+
+		ret = apple_smc_read_u8(smc, SMC_KEY(MSLD), &val);
+		if (ret < 0)
+			dev_warn(&pdev->dev, "Failed to read initial lid state\n");
+		else
+			input_report_switch(smchid->input, SW_LID, val);
+	}
+
+	if (have_power) {
+		u32 val;
+
+		ret = apple_smc_read_u32(smc, SMC_KEY(bHLD), &val);
+		if (ret < 0)
+			dev_warn(&pdev->dev, "Failed to read initial power button state\n");
+		else
+			input_report_key(smchid->input, KEY_POWER, val & 1);
+	}
+
+	input_sync(smchid->input);
+
+	smchid->nb.notifier_call = macsmc_hid_event;
+	blocking_notifier_chain_register(&smc->event_handlers, &smchid->nb);
+
+	device_init_wakeup(&pdev->dev, 1);
+
+	return 0;
+}
+
+static int macsmc_hid_pm_prepare(struct device *dev)
+{
+	struct macsmc_hid *smchid = dev_get_drvdata(dev);
+
+	smchid->wakeup_mode = true;
+	return 0;
+}
+
+static void macsmc_hid_pm_complete(struct device *dev)
+{
+	struct macsmc_hid *smchid = dev_get_drvdata(dev);
+
+	smchid->wakeup_mode = false;
+}
+
+static const struct dev_pm_ops macsmc_hid_pm_ops = {
+	.prepare = macsmc_hid_pm_prepare,
+	.complete = macsmc_hid_pm_complete,
+};
+
+static struct platform_driver macsmc_hid_driver = {
+	.driver = {
+		.name = "macsmc-hid",
+		.pm = &macsmc_hid_pm_ops,
+	},
+	.probe = macsmc_hid_probe,
+};
+module_platform_driver(macsmc_hid_driver);
+
+MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_DESCRIPTION("Apple SMC HID driver");
+MODULE_ALIAS("platform:macsmc-hid");

-- 
2.51.0

[PATCH v2 08/11] mfd: macsmc: Wire up Apple SMC HID subdevice

[James Calligeros]

Add the new SMC HID function to the mfd device

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/mfd/macsmc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/macsmc.c b/drivers/mfd/macsmc.c
index 286dc150aa6cfdd6d29f769094278daaddabe7c3..893fc47d62b2c956d966d1841895a3fa2b9a3005 100644
--- a/drivers/mfd/macsmc.c
+++ b/drivers/mfd/macsmc.c
@@ -45,6 +45,7 @@
 #define SMC_TIMEOUT_MS		500
 
 static const struct mfd_cell apple_smc_devs[] = {
+	MFD_CELL_NAME("macsmc-hid"),
 	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"),

-- 
2.51.0

[PATCH v2 09/11] arm64: dts: apple: t8103,t600x,t8112: Add SMC RTC node

[James Calligeros]

From: Sven Peter <sven@kernel.org>

The System Manager Controller of all M1/M2 SoCs supports the RTC
sub-device.

Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Sven Peter <sven@kernel.org>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 .../arm64/boot/dts/apple/t600x-die0.dtsi | 6 ++++++
 arch/arm64/boot/dts/apple/t8103.dtsi     | 6 ++++++
 arch/arm64/boot/dts/apple/t8112.dtsi     | 6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/t600x-die0.dtsi b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
index 3603b276a2abcfa6a730f58d5c6b9914f22f00b0..f715b19efd1679e5cd384a967d6e2a7c261ee679 100644
--- a/arch/arm64/boot/dts/apple/t600x-die0.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
@@ -44,6 +44,12 @@ smc_reboot: reboot {
 			nvmem-cell-names = "shutdown_flag", "boot_stage",
 				"boot_error_count", "panic_count";
 		};
+
+		rtc {
+			compatible = "apple,smc-rtc";
+			nvmem-cells = <&rtc_offset>;
+			nvmem-cell-names = "rtc_offset";
+		};
 	};
 
 	smc_mbox: mbox@290408000 {
diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
index 8b7b27887968741b745651e5133dffa7d8d20f6d..59f2678639cf47f469dc699c0ecb5b9e50a45ab1 100644
--- a/arch/arm64/boot/dts/apple/t8103.dtsi
+++ b/arch/arm64/boot/dts/apple/t8103.dtsi
@@ -916,6 +916,12 @@ smc_reboot: reboot {
 				nvmem-cell-names = "shutdown_flag", "boot_stage",
 					"boot_error_count", "panic_count";
 			};
+
+			rtc {
+				compatible = "apple,smc-rtc";
+				nvmem-cells = <&rtc_offset>;
+				nvmem-cell-names = "rtc_offset";
+			};
 		};
 
 		smc_mbox: mbox@23e408000 {
diff --git a/arch/arm64/boot/dts/apple/t8112.dtsi b/arch/arm64/boot/dts/apple/t8112.dtsi
index 3f79878b25af1f7760088aa552589494d67347fb..6bc3f58b06f703ed79578e89a030929a18d57796 100644
--- a/arch/arm64/boot/dts/apple/t8112.dtsi
+++ b/arch/arm64/boot/dts/apple/t8112.dtsi
@@ -919,6 +919,12 @@ smc_reboot: reboot {
 				nvmem-cell-names = "shutdown_flag", "boot_stage",
 					"boot_error_count", "panic_count";
 			};
+
+			rtc {
+				compatible = "apple,smc-rtc";
+				nvmem-cells = <&rtc_offset>;
+				nvmem-cell-names = "rtc_offset";
+			};
 		};
 
 		smc_mbox: mbox@23e408000 {

-- 
2.51.0

[PATCH v2 10/11] arm64: dts: apple: Add common hwmon sensors and fans

[James Calligeros]

Each Apple Silicon device exposes a unique set of sensors and fans,
however some have been found to be reliably common across devices.

Add these as .dtsi files so that they can be combined with any
device-specific sensors without excessive repetition.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 .../boot/dts/apple/hwmon-common.dtsi     | 37 +++++++++++++++++++++++++
 .../boot/dts/apple/hwmon-fan-dual.dtsi   | 24 ++++++++++++++++
 arch/arm64/boot/dts/apple/hwmon-fan.dtsi | 19 +++++++++++++
 .../boot/dts/apple/hwmon-laptop.dtsi     | 35 +++++++++++++++++++++++
 .../boot/dts/apple/hwmon-mac-mini.dtsi   | 17 ++++++++++++
 5 files changed, 132 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/hwmon-common.dtsi b/arch/arm64/boot/dts/apple/hwmon-common.dtsi
new file mode 100644
index 0000000000000000000000000000000000000000..bac4e44d3f9892fe8ad04125e47dcccb2bcf57a0
--- /dev/null
+++ b/arch/arm64/boot/dts/apple/hwmon-common.dtsi
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Hardawre monitoring sensors expected to be found on all Apple Silicon devices
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+&smc {
+	hwmon {
+		compatible = "apple,smc-hwmon";
+
+		current-ID0R {
+			apple,key-id = "ID0R";
+			label = "AC Input Current";
+		};
+		power-PSTR {
+			apple,key-id = "PSTR";
+			label = "Total System Power";
+		};
+		power-PDTR {
+			apple,key-id = "PDTR";
+			label = "AC Input Power";
+		};
+		power-PMVR {
+			apple,key-id = "PMVR";
+			label = "3.8 V Rail Power";
+		};
+		temperature-TH0x {
+			apple,key-id = "TH0x";
+			label = "NAND Flash Temperature";
+		};
+		voltage-VD0R {
+			apple,key-id = "VD0R";
+			label = "AC Input Voltage";
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/apple/hwmon-fan-dual.dtsi b/arch/arm64/boot/dts/apple/hwmon-fan-dual.dtsi
new file mode 100644
index 0000000000000000000000000000000000000000..f81047725de473b85d8f337af63fa10d3aa827a0
--- /dev/null
+++ b/arch/arm64/boot/dts/apple/hwmon-fan-dual.dtsi
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * SMC hwmon fan keys for Apple Silicon desktops/laptops with two fans
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include "hwmon-fan.dtsi"
+
+&smc {
+	hwmon {
+		fan-F0Ac {
+			label = "Fan 1";
+		};
+		fan-F1Ac {
+			apple,key-id = "F1Ac";
+			label = "Fan 2";
+			apple,fan-minimum = "F1Mn";
+			apple,fan-maximum = "F1Mx";
+			apple,fan-target = "F1Tg";
+			apple,fan-mode = "F1Md";
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/apple/hwmon-fan.dtsi b/arch/arm64/boot/dts/apple/hwmon-fan.dtsi
new file mode 100644
index 0000000000000000000000000000000000000000..ae5e1a54b6b780ff880ca0a39bc2712d8cbafbe4
--- /dev/null
+++ b/arch/arm64/boot/dts/apple/hwmon-fan.dtsi
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * hwmon fan keys for Apple Silicon desktops/laptops with a single fan.
+ *
+ *  Copyright The Asahi Linux Contributors
+ */
+
+&smc {
+	hwmon {
+		fan-F0Ac {
+			apple,key-id = "F0Ac";
+			label = "Fan";
+			apple,fan-minimum = "F0Mn";
+			apple,fan-maximum = "F0Mx";
+			apple,fan-target = "F0Tg";
+			apple,fan-mode = "F0Md";
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/apple/hwmon-laptop.dtsi b/arch/arm64/boot/dts/apple/hwmon-laptop.dtsi
new file mode 100644
index 0000000000000000000000000000000000000000..227dc5065bb2b74d9699019b71eed90501e1b4b1
--- /dev/null
+++ b/arch/arm64/boot/dts/apple/hwmon-laptop.dtsi
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Hardware monitoring sensors expected on all Apple Silicon laptops
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+&smc {
+	hwmon {
+		power-PHPC {
+			apple,key-id = "PHPC";
+			label = "Heatpipe Power";
+		};
+		temperature-TB0T {
+			apple,key-id = "TB0T";
+			label = "Battery Hotspot Temperature";
+		};
+		temperature-TCHP {
+			apple,key-id = "TCHP";
+			label = "Charge Regulator Temperature";
+		};
+		temperature-TW0P {
+			apple,key-id = "TW0P";
+			label = "WiFi/BT Module Temperature";
+		};
+		voltage-SBAV {
+			apple,key-id = "SBAV";
+			label = "Battery Voltage";
+		};
+		voltage-VD0R {
+			apple,key-id = "VD0R";
+			label = "Charger Input Voltage";
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/apple/hwmon-mac-mini.dtsi b/arch/arm64/boot/dts/apple/hwmon-mac-mini.dtsi
new file mode 100644
index 0000000000000000000000000000000000000000..6344deff06ebb9c1b0fbbf6b986db879eb5f19cc
--- /dev/null
+++ b/arch/arm64/boot/dts/apple/hwmon-mac-mini.dtsi
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * hwmon sensors expected on all Mac mini models
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include "hwmon-fan.dtsi"
+
+&smc {
+	hwmon {
+		temperature-TW0P {
+			apple,key-id = "TW0P";
+			label = "WiFi/BT Module Temperature";
+		};
+	};
+};

-- 
2.51.0

[PATCH v2 11/11] arm64: dts: apple: t8103, t600x, t8112: Add common hwmon nodes to devices

[James Calligeros]

Add the known, common hwmon-related SMC keys to the DTs for the devices
they pertain to.

Co-developed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 .../arm64/boot/dts/apple/t6001-j375c.dts | 2 ++
 .../arm64/boot/dts/apple/t6002-j375d.dts | 2 ++
 .../boot/dts/apple/t600x-j314-j316.dtsi  | 4 ++++
 .../arm64/boot/dts/apple/t600x-j375.dtsi | 2 ++
 arch/arm64/boot/dts/apple/t8103-j274.dts | 2 ++
 arch/arm64/boot/dts/apple/t8103-j293.dts | 3 +++
 arch/arm64/boot/dts/apple/t8103-j313.dts | 2 ++
 arch/arm64/boot/dts/apple/t8103-j456.dts | 2 ++
 arch/arm64/boot/dts/apple/t8103-j457.dts | 2 ++
 .../arm64/boot/dts/apple/t8103-jxxx.dtsi | 2 ++
 arch/arm64/boot/dts/apple/t8112-j413.dts | 2 ++
 arch/arm64/boot/dts/apple/t8112-j473.dts | 2 ++
 arch/arm64/boot/dts/apple/t8112-j493.dts | 3 +++
 .../arm64/boot/dts/apple/t8112-jxxx.dtsi | 2 ++
 14 files changed, 32 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/t6001-j375c.dts b/arch/arm64/boot/dts/apple/t6001-j375c.dts
index 62ea437b58b25ca649e20b1072b4d835bbc17d3a..9e8c4107e65d8dc47ad2ad99af2f436613c11d8f 100644
--- a/arch/arm64/boot/dts/apple/t6001-j375c.dts
+++ b/arch/arm64/boot/dts/apple/t6001-j375c.dts
@@ -16,3 +16,5 @@ / {
 	compatible = "apple,j375c", "apple,t6001", "apple,arm-platform";
 	model = "Apple Mac Studio (M1 Max, 2022)";
 };
+
+#include "hwmon-fan-dual.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t6002-j375d.dts b/arch/arm64/boot/dts/apple/t6002-j375d.dts
index 3365429bdc8be90b63c8051822243d897854ab27..b62cf16d6b73e74c3d9116730b44596be2a89ea0 100644
--- a/arch/arm64/boot/dts/apple/t6002-j375d.dts
+++ b/arch/arm64/boot/dts/apple/t6002-j375d.dts
@@ -48,3 +48,5 @@ hpm5: usb-pd@3a {
 
 /delete-node/ &ps_disp0_cpu0_die1;
 /delete-node/ &ps_disp0_fe_die1;
+
+#include "hwmon-fan-dual.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi b/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
index 22ebc78e120bf8f0f71fd532e9dce4dcd117bbc6..2cb38861c3855e31c9b8ab66fe69b818c381c604 100644
--- a/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi
@@ -121,3 +121,7 @@ &fpwm0 {
 };
 
 #include "spi1-nvram.dtsi"
+
+#include "hwmon-common.dtsi"
+#include "hwmon-laptop.dtsi"
+#include "hwmon-fan-dual.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t600x-j375.dtsi b/arch/arm64/boot/dts/apple/t600x-j375.dtsi
index d5b985ad567936111ee5cccc9ca9fc23d01d9edf..7e551e8660c9c2b51f021b1188680c5cce9d2951 100644
--- a/arch/arm64/boot/dts/apple/t600x-j375.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-j375.dtsi
@@ -128,3 +128,5 @@ &pcie0_dart_3 {
 };
 
 #include "spi1-nvram.dtsi"
+
+#include "hwmon-common.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8103-j274.dts b/arch/arm64/boot/dts/apple/t8103-j274.dts
index 1c3e37f86d46d7b5d733717b47c4b57dc55e1201..f5b8cc087882d6bd2b0f4f2711844d2a0fa8b604 100644
--- a/arch/arm64/boot/dts/apple/t8103-j274.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j274.dts
@@ -61,3 +61,5 @@ &pcie0_dart_2 {
 &i2c2 {
 	status = "okay";
 };
+
+#include "hwmon-mac-mini.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8103-j293.dts b/arch/arm64/boot/dts/apple/t8103-j293.dts
index 5b3c42e9f0e6776241bf746d3458766e44e3639a..abb88391635fa048c196d0631d90405519ddd178 100644
--- a/arch/arm64/boot/dts/apple/t8103-j293.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j293.dts
@@ -119,3 +119,6 @@ dfr_panel_in: endpoint {
 &displaydfr_dart {
 	status = "okay";
 };
+
+#include "hwmon-laptop.dtsi"
+#include "hwmon-fan.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8103-j313.dts b/arch/arm64/boot/dts/apple/t8103-j313.dts
index 97a4344d8dca685708aff136af92a1b316f3c3dd..491ead016b2193f123f4ded9dadf85ebf37cdc7e 100644
--- a/arch/arm64/boot/dts/apple/t8103-j313.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j313.dts
@@ -41,3 +41,5 @@ &wifi0 {
 &fpwm1 {
 	status = "okay";
 };
+
+#include "hwmon-laptop.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8103-j456.dts b/arch/arm64/boot/dts/apple/t8103-j456.dts
index 58c8e43789b4861544e20c717124ede3327be010..c2ec6fbb633cc6aeec2322f295c054998fbf08cc 100644
--- a/arch/arm64/boot/dts/apple/t8103-j456.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j456.dts
@@ -75,3 +75,5 @@ &pcie0_dart_1 {
 &pcie0_dart_2 {
 	status = "okay";
 };
+
+#include "hwmon-fan-dual.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8103-j457.dts b/arch/arm64/boot/dts/apple/t8103-j457.dts
index 152f95fd49a2118093396838fbd8b6bd1b518f81..20e85612ae70c116cab788f2c03f5a7d76cb19be 100644
--- a/arch/arm64/boot/dts/apple/t8103-j457.dts
+++ b/arch/arm64/boot/dts/apple/t8103-j457.dts
@@ -48,3 +48,5 @@ ethernet0: ethernet@0,0 {
 &pcie0_dart_2 {
 	status = "okay";
 };
+
+#include "hwmon-fan.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8103-jxxx.dtsi b/arch/arm64/boot/dts/apple/t8103-jxxx.dtsi
index 0c8206156bfefda8a32c869787b2e0c8e67a9d17..f711af410a2edf7587ff091e195c5cf243dc8a34 100644
--- a/arch/arm64/boot/dts/apple/t8103-jxxx.dtsi
+++ b/arch/arm64/boot/dts/apple/t8103-jxxx.dtsi
@@ -92,3 +92,5 @@ &nco_clkref {
 };
 
 #include "spi1-nvram.dtsi"
+
+#include "hwmon-common.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8112-j413.dts b/arch/arm64/boot/dts/apple/t8112-j413.dts
index 6f69658623bf89ce73e3486bce504f1f5f8003f3..500dcdf2d4b5da698ee0798f37f624ff70e7b9f0 100644
--- a/arch/arm64/boot/dts/apple/t8112-j413.dts
+++ b/arch/arm64/boot/dts/apple/t8112-j413.dts
@@ -78,3 +78,5 @@ &i2c4 {
 &fpwm1 {
 	status = "okay";
 };
+
+#include "hwmon-laptop.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8112-j473.dts b/arch/arm64/boot/dts/apple/t8112-j473.dts
index 06fe257f08be498ace6906b936012e01084da702..11db6a92493f367cfa64be5e844c80e99bdd325b 100644
--- a/arch/arm64/boot/dts/apple/t8112-j473.dts
+++ b/arch/arm64/boot/dts/apple/t8112-j473.dts
@@ -52,3 +52,5 @@ &pcie1_dart {
 &pcie2_dart {
 	status = "okay";
 };
+
+#include "hwmon-mac-mini.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8112-j493.dts b/arch/arm64/boot/dts/apple/t8112-j493.dts
index fb8ad7d4c65a8fe7966f5541f24f03a379143cfb..a0da02c00f157a0e667b26aebef9157636b14ecf 100644
--- a/arch/arm64/boot/dts/apple/t8112-j493.dts
+++ b/arch/arm64/boot/dts/apple/t8112-j493.dts
@@ -133,3 +133,6 @@ touchbar0: touchbar@0 {
 		touchscreen-inverted-y;
 	};
 };
+
+#include "hwmon-laptop.dtsi"
+#include "hwmon-fan.dtsi"
diff --git a/arch/arm64/boot/dts/apple/t8112-jxxx.dtsi b/arch/arm64/boot/dts/apple/t8112-jxxx.dtsi
index 6da35496a4c88dbaba125ebbe8c5a4a428c647c3..6e54c1fb097e8f72cb4fb37e491893a7e3d7e6c2 100644
--- a/arch/arm64/boot/dts/apple/t8112-jxxx.dtsi
+++ b/arch/arm64/boot/dts/apple/t8112-jxxx.dtsi
@@ -81,3 +81,5 @@ &nco_clkref {
 };
 
 #include "spi1-nvram.dtsi"
+
+#include "hwmon-common.dtsi"

-- 
2.51.0

Re: [PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[Guenter Roeck]

On 8/27/25 04:22, James Calligeros wrote:
> Hi all,
> 
> This series adds support for the remaining SMC subdevices. These are the
> RTC, hwmon, and HID devices. They are being submitted together as the RTC
> and hwmon drivers both require changes to the SMC DT schema.
> 
> The RTC driver is responsible for getting and setting the system clock,
> and requires an NVMEM cell. This series replaces Sven's original RTC driver
> submission [1].
> 
> The hwmon function is an interesting one. While each Apple Silicon device
> exposes pretty similar sets of sensors, these all seem to be paired to
> different SMC keys in the firmware interface. This is true even when the
> sensors are on the SoC. For example, an M1 MacBook Pro will use different
> keys to access the LITTLE core temperature sensors to an M1 Mac mini. This
> necessitates describing which keys correspond to which sensors for each
> device individually, and populating the hwmon structs at runtime. We do
> this with a node in the device tree. This series includes only the keys
> for sensors which we know to be common to all devices. The SMC is also
> responsible for monitoring and controlling fan speeds on systems with fans,
> which we expose via the hwmon driver.
> 
> The SMC also handles the hardware power button and lid switch. Power
> button presses and lid opening/closing are emitted as HID events, so we
> add a HID subdevice to handle them.
> 
> Note that this series is based on a branch with three additional commits
> applied to add the parent SMC nodes to the relevant Devicetrees. This
> was done to silence build errors. The series applies cleanly to 6.17-rc1.
> 
> Regards,
> 
> James
> 
> [1] https://lore.kernel.org/asahi/CAEg-Je84XxLWH7vznQmPRfjf6GxWOu75ZetwN7AdseAwfMLLrQ@mail.gmail.com/T/#t
> 
> Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
> ---
> Changes in v2:
> - Added Rob's R-b tag to RTC DT binding
> - Removed redundant nesting from hwmon DT binding
> - Dedpulicated property definitions in hwmon DT schema
> - Made label a required property for hwmon DT nodes
> - Clarified semantics in hwmon DT schema definitions
> - Split mfd tree changes into separate commits
> - Fixed numerous style errors in hwmon driver
> - Addressed Guenter's initial feedback on the hwmon driver

Don't you think that is a bit useless ? You might as well say "Addressed
feedback comments" and be done with the change log.

Guenter

Re: [PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[James Calligeros]

On Wed, Aug 27, 2025 at 11:47 PM Guenter Roeck <linux@roeck-us.net> wrote:
> > ---
> > Changes in v2:
> > - Added Rob's R-b tag to RTC DT binding
> > - Removed redundant nesting from hwmon DT binding
> > - Dedpulicated property definitions in hwmon DT schema
> > - Made label a required property for hwmon DT nodes
> > - Clarified semantics in hwmon DT schema definitions
> > - Split mfd tree changes into separate commits
> > - Fixed numerous style errors in hwmon driver
> > - Addressed Guenter's initial feedback on the hwmon driver
>
> Don't you think that is a bit useless ? You might as well say "Addressed
> feedback comments" and be done with the change log.
>
> Guenter

I don't think this warrants a v3, so hopefully the amended
changelog below will suffice.

---
Changes in v2:
- Added Rob's R-b tag to RTC DT binding
- Removed redundant nesting from hwmon DT binding
- Dedpulicated property definitions in hwmon DT schema
- Made label a required property for hwmon DT nodes
- Clarified semantics in hwmon DT schema definitions
- Split mfd tree changes into separate commits
- Fixed numerous style errors in hwmon driver
- Removed log messages sysfs read/write functions in hwmon driver
- Removed ignored errors from hwmon driver
- Removed uses of dev_err for non-errors in hwmon driver
- Made it more obvious that a number of hwmon fan properties are optional
- Modified hwmon driver to reflect DT schema changes
- Added compatible property to hwmon node
- Link to v1: https://lore.kernel.org/r/20250819-macsmc-subdevs-v1-0-57df6c3e5f19@gmail.com

James

Re: [PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[Neal Gompa]

On Wed, Aug 27, 2025 at 6:07 PM James Calligeros
<jcalligeros99@gmail.com> wrote:
>
> On Wed, Aug 27, 2025 at 11:47 PM Guenter Roeck <linux@roeck-us.net> wrote:
> > > ---
> > > Changes in v2:
> > > - Added Rob's R-b tag to RTC DT binding
> > > - Removed redundant nesting from hwmon DT binding
> > > - Dedpulicated property definitions in hwmon DT schema
> > > - Made label a required property for hwmon DT nodes
> > > - Clarified semantics in hwmon DT schema definitions
> > > - Split mfd tree changes into separate commits
> > > - Fixed numerous style errors in hwmon driver
> > > - Addressed Guenter's initial feedback on the hwmon driver
> >
> > Don't you think that is a bit useless ? You might as well say "Addressed
> > feedback comments" and be done with the change log.
> >
> > Guenter
>
> I don't think this warrants a v3, so hopefully the amended
> changelog below will suffice.
>
> ---
> Changes in v2:
> - Added Rob's R-b tag to RTC DT binding
> - Removed redundant nesting from hwmon DT binding
> - Dedpulicated property definitions in hwmon DT schema
> - Made label a required property for hwmon DT nodes
> - Clarified semantics in hwmon DT schema definitions
> - Split mfd tree changes into separate commits
> - Fixed numerous style errors in hwmon driver
> - Removed log messages sysfs read/write functions in hwmon driver
> - Removed ignored errors from hwmon driver
> - Removed uses of dev_err for non-errors in hwmon driver
> - Made it more obvious that a number of hwmon fan properties are optional
> - Modified hwmon driver to reflect DT schema changes
> - Added compatible property to hwmon node
> - Link to v1: https://lore.kernel.org/r/20250819-macsmc-subdevs-v1-0-57df6c3e5f19@gmail.com
>

Series LGTM.

Reviewed-by: Neal Gompa <neal@gompa.dev>



-- 
真実はいつも一つ！/ Always, there's only one truth!

Re: [PATCH v2 00/11] mfd: macsmc: add rtc, hwmon and hid subdevices

[Alexandre Belloni]

Hello,

On 27/08/2025 21:22:34+1000, James Calligeros wrote:
> Hi all,
> 
> This series adds support for the remaining SMC subdevices. These are the
> RTC, hwmon, and HID devices. They are being submitted together as the RTC
> and hwmon drivers both require changes to the SMC DT schema.
> 

How do you expect this to be merged? From what I get, I could just take
1 and 3 as there doesn't seem to be any actual dependencies on any of
the other patches and the MFD change doesn't depend on the RTC changes.

> The RTC driver is responsible for getting and setting the system clock,
> and requires an NVMEM cell. This series replaces Sven's original RTC driver
> submission [1].
> 
> The hwmon function is an interesting one. While each Apple Silicon device
> exposes pretty similar sets of sensors, these all seem to be paired to
> different SMC keys in the firmware interface. This is true even when the
> sensors are on the SoC. For example, an M1 MacBook Pro will use different
> keys to access the LITTLE core temperature sensors to an M1 Mac mini. This
> necessitates describing which keys correspond to which sensors for each
> device individually, and populating the hwmon structs at runtime. We do
> this with a node in the device tree. This series includes only the keys
> for sensors which we know to be common to all devices. The SMC is also
> responsible for monitoring and controlling fan speeds on systems with fans,
> which we expose via the hwmon driver.
> 
> The SMC also handles the hardware power button and lid switch. Power
> button presses and lid opening/closing are emitted as HID events, so we
> add a HID subdevice to handle them.
> 
> Note that this series is based on a branch with three additional commits
> applied to add the parent SMC nodes to the relevant Devicetrees. This
> was done to silence build errors. The series applies cleanly to 6.17-rc1.
> 
> Regards,
> 
> James
> 
> [1] https://lore.kernel.org/asahi/CAEg-Je84XxLWH7vznQmPRfjf6GxWOu75ZetwN7AdseAwfMLLrQ@mail.gmail.com/T/#t
> 
> Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
> ---
> Changes in v2:
> - Added Rob's R-b tag to RTC DT binding
> - Removed redundant nesting from hwmon DT binding
> - Dedpulicated property definitions in hwmon DT schema
> - Made label a required property for hwmon DT nodes
> - Clarified semantics in hwmon DT schema definitions
> - Split mfd tree changes into separate commits
> - Fixed numerous style errors in hwmon driver
> - Addressed Guenter's initial feedback on the hwmon driver
> - Modified hwmon driver to reflect DT schema changes
> - Added compatible property to hwmon node
> - Link to v1: https://lore.kernel.org/r/20250819-macsmc-subdevs-v1-0-57df6c3e5f19@gmail.com
> 
> ---
> Hector Martin (2):
>       rtc: Add new rtc-macsmc driver for Apple Silicon Macs
>       input: macsmc-hid: New driver to handle the Apple Mac SMC buttons/lid
> 
> James Calligeros (7):
>       dt-bindings: hwmon: Add Apple System Management Controller hwmon schema
>       mfd: macsmc: Wire up Apple SMC RTC subdevice
>       hwmon: Add Apple Silicon SMC hwmon driver
>       mfd: macsmc: Wire up Apple SMC hwmon subdevice
>       mfd: macsmc: Wire up Apple SMC HID subdevice
>       arm64: dts: apple: Add common hwmon sensors and fans
>       arm64: dts: apple: t8103, t600x, t8112: Add common hwmon nodes to devices
> 
> Sven Peter (2):
>       dt-bindings: rtc: Add Apple SMC RTC
>       arm64: dts: apple: t8103,t600x,t8112: Add SMC RTC node
> 
>  .../bindings/hwmon/apple,smc-hwmon.yaml  | 132 ++++
>  .../bindings/mfd/apple,smc.yaml          |  45 ++
>  .../bindings/rtc/apple,smc-rtc.yaml      |  35 +
>  MAINTAINERS                              |   5 +
>  .../boot/dts/apple/hwmon-common.dtsi     |  37 ++
>  .../boot/dts/apple/hwmon-fan-dual.dtsi   |  24 +
>  arch/arm64/boot/dts/apple/hwmon-fan.dtsi |  19 +
>  .../boot/dts/apple/hwmon-laptop.dtsi     |  35 +
>  .../boot/dts/apple/hwmon-mac-mini.dtsi   |  17 +
>  .../arm64/boot/dts/apple/t6001-j375c.dts |   2 +
>  .../arm64/boot/dts/apple/t6002-j375d.dts |   2 +
>  .../arm64/boot/dts/apple/t600x-die0.dtsi |   6 +
>  .../boot/dts/apple/t600x-j314-j316.dtsi  |   4 +
>  .../arm64/boot/dts/apple/t600x-j375.dtsi |   2 +
>  arch/arm64/boot/dts/apple/t8103-j274.dts |   2 +
>  arch/arm64/boot/dts/apple/t8103-j293.dts |   3 +
>  arch/arm64/boot/dts/apple/t8103-j313.dts |   2 +
>  arch/arm64/boot/dts/apple/t8103-j456.dts |   2 +
>  arch/arm64/boot/dts/apple/t8103-j457.dts |   2 +
>  .../arm64/boot/dts/apple/t8103-jxxx.dtsi |   2 +
>  arch/arm64/boot/dts/apple/t8103.dtsi     |   6 +
>  arch/arm64/boot/dts/apple/t8112-j413.dts |   2 +
>  arch/arm64/boot/dts/apple/t8112-j473.dts |   2 +
>  arch/arm64/boot/dts/apple/t8112-j493.dts |   3 +
>  .../arm64/boot/dts/apple/t8112-jxxx.dtsi |   2 +
>  arch/arm64/boot/dts/apple/t8112.dtsi     |   6 +
>  drivers/hwmon/Kconfig                    |  12 +
>  drivers/hwmon/Makefile                   |   1 +
>  drivers/hwmon/macsmc_hwmon.c             | 848 +++++++++++++++++++++++++
>  drivers/input/misc/Kconfig               |  11 +
>  drivers/input/misc/Makefile              |   1 +
>  drivers/input/misc/macsmc-hid.c          | 209 ++++++
>  drivers/mfd/macsmc.c                     |   3 +
>  drivers/rtc/Kconfig                      |  11 +
>  drivers/rtc/Makefile                     |   1 +
>  drivers/rtc/rtc-macsmc.c                 | 141 ++++
>  36 files changed, 1637 insertions(+)
> ---
> base-commit: 876d6a70b24869f96ebc8672caf86cb4bae72927
> change-id: 20250816-macsmc-subdevs-87032c017d0c
> 
> Best regards,
> -- 
> James Calligeros <jcalligeros99@gmail.com>
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v2 05/11] hwmon: Add Apple Silicon SMC hwmon driver

[Guenter Roeck]

On Wed, Aug 27, 2025 at 09:22:39PM +1000, James Calligeros wrote:
> The System Management Controller on Apple Silicon devices is responsible
> for integrating and exposing the data reported by the vast array of
> hardware monitoring sensors present on these devices. It is also
> responsible for fan control, and allows users to manually set fan
> speeds if they so desire. Add a hwmon driver to expose current,
> power, temperature, and voltage monitoring sensors, as well as
> fan speed monitoring and control via the SMC on Apple Silicon devices.
> 
> The SMC firmware has no consistency between devices, even when they
> share an SoC. The FourCC keys used to access sensors are almost
> random. An M1 Mac mini will have different FourCCs for its CPU core
> temperature sensors to an M1 MacBook Pro, for example. For this
> reason, the valid sensors for a given device are specified in a
> child of the SMC Devicetree node. The driver uses this information
> to determine which sensors to make available at runtime.
> 
> Co-developed-by: Janne Grunau <j@jannau.net>
> Signed-off-by: Janne Grunau <j@jannau.net>
> Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
> ---
>  MAINTAINERS                  |   1 +
>  drivers/hwmon/Kconfig        |  12 +
>  drivers/hwmon/Makefile       |   1 +
>  drivers/hwmon/macsmc_hwmon.c | 848 +++++++++++++++++++++++++

Documentation/hwmon/macsmc_hwmon missing

>  4 files changed, 862 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5d53d243dc9abdf1db5865f8e6bcddbac3eafebe..2eb23522654dd050262eb06e077587030cc335aa 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2408,6 +2408,7 @@ F:	drivers/clk/clk-apple-nco.c
>  F:	drivers/cpufreq/apple-soc-cpufreq.c
>  F:	drivers/dma/apple-admac.c
>  F:	drivers/gpio/gpio-macsmc.c
> +F:	drivers/hwmon/macsmc_hwmon.c
>  F:	drivers/pmdomain/apple/
>  F:	drivers/i2c/busses/i2c-pasemi-core.c
>  F:	drivers/i2c/busses/i2c-pasemi-platform.c
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 9d28fcf7cd2a6f9e2f54694a717bd85ff4047b46..1ca6db71e4d9da32717fd14487c10944433ada41 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1164,6 +1164,18 @@ config SENSORS_LTQ_CPUTEMP
>  	  If you say yes here you get support for the temperature
>  	  sensor inside your CPU.
>  
> +config SENSORS_MACSMC_HWMON
> +	tristate "Apple SMC (Apple Silicon)"
> +	depends on MFD_MACSMC && OF
> +	help
> +	  This driver enables hwmon support for current, power, temperature,
> +	  and voltage sensors, as well as fan speed reporting and control
> +	  on Apple Silicon devices. Say Y here if you have an Apple Silicon
> +	  device.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called macsmc_hwmon.
> +
>  config SENSORS_MAX1111
>  	tristate "Maxim MAX1111 Serial 8-bit ADC chip and compatibles"
>  	depends on SPI_MASTER
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index cd8bc4752b4dbf015c6eb46157626f4e8f87dfae..80fc8447aff15b3b8e8583dc755c8accb3b6a93e 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_LTC4260)	+= ltc4260.o
>  obj-$(CONFIG_SENSORS_LTC4261)	+= ltc4261.o
>  obj-$(CONFIG_SENSORS_LTC4282)	+= ltc4282.o
>  obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
> +obj-$(CONFIG_SENSORS_MACSMC_HWMON)	+= macsmc_hwmon.o
>  obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o
>  obj-$(CONFIG_SENSORS_MAX127)	+= max127.o
>  obj-$(CONFIG_SENSORS_MAX16065)	+= max16065.o
> diff --git a/drivers/hwmon/macsmc_hwmon.c b/drivers/hwmon/macsmc_hwmon.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..e44ea357870238aa0b38d7b674a6c456271fdf0c
> --- /dev/null
> +++ b/drivers/hwmon/macsmc_hwmon.c
> @@ -0,0 +1,848 @@
> +// SPDX-License-Identifier: GPL-2.0-only OR MIT
> +/*
> + * Apple SMC hwmon driver for Apple Silicon platforms
> + *
> + * The System Management Controller on Apple Silicon devices is responsible for
> + * measuring data from sensors across the SoC and machine. These include power,
> + * temperature, voltage and current sensors. Some "sensors" actually expose
> + * derived values. An example of this is the key PHPC, which is an estimate
> + * of the heat energy being dissipated by the SoC.
> + *
> + * While each SoC only has one SMC variant, each platform exposes a different
> + * set of sensors. For example, M1 MacBooks expose battery telemetry sensors
> + * which are not present on the M1 Mac mini. For this reason, the available
> + * sensors for a given platform are described in the device tree in a child
> + * node of the SMC device. We must walk this list of available sensors and
> + * populate the required hwmon data structures at runtime.
> + *
> + * Originally based on a concept by Jean-Francois Bortolotti <jeff@borto.fr>
> + *
> + * Copyright The Asahi Linux Contributors
> + */
> +
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>

Unnecessary include file

> +#include <linux/mfd/macsmc.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +
> +#define MAX_LABEL_LENGTH	32
> +#define NUM_SENSOR_TYPES	5 /* temp, volt, current, power, fan */
> +
> +#define FLT_EXP_BIAS	127
> +#define FLT_EXP_MASK	GENMASK(30, 23)
> +#define FLT_MANT_BIAS	23
> +#define FLT_MANT_MASK	GENMASK(22, 0)
> +#define FLT_SIGN_MASK	BIT(31)
> +
> +static bool fan_control;
> +module_param_unsafe(fan_control, bool, 0644);
> +MODULE_PARM_DESC(fan_control,
> +		 "Override the SMC to set your own fan speeds on supported machines");
> +
> +struct macsmc_hwmon_sensor {
> +	struct apple_smc_key_info info;
> +	smc_key macsmc_key;
> +	char label[MAX_LABEL_LENGTH];
> +};
> +
> +struct macsmc_hwmon_fan {
> +	struct macsmc_hwmon_sensor now;
> +	struct macsmc_hwmon_sensor min;
> +	struct macsmc_hwmon_sensor max;
> +	struct macsmc_hwmon_sensor set;
> +	struct macsmc_hwmon_sensor mode;
> +	char label[MAX_LABEL_LENGTH];
> +	u32 attrs;
> +	bool manual;
> +};
> +
> +struct macsmc_hwmon_sensors {
> +	struct hwmon_channel_info channel_info;
> +	struct macsmc_hwmon_sensor *sensors;
> +	u32 count;
> +};
> +
> +struct macsmc_hwmon_fans {
> +	struct hwmon_channel_info channel_info;
> +	struct macsmc_hwmon_fan *fans;
> +	u32 count;
> +};
> +
> +struct macsmc_hwmon {
> +	struct device *dev;
> +	struct apple_smc *smc;
> +	struct device *hwmon_dev;
> +	struct hwmon_chip_info chip_info;
> +	/* Chip + sensor types + NULL */
> +	const struct hwmon_channel_info *channel_infos[1 + NUM_SENSOR_TYPES + 1];
> +	struct macsmc_hwmon_sensors temp;
> +	struct macsmc_hwmon_sensors volt;
> +	struct macsmc_hwmon_sensors curr;
> +	struct macsmc_hwmon_sensors power;
> +	struct macsmc_hwmon_fans fan;
> +};
> +
> +static int macsmc_hwmon_read_label(struct device *dev,
> +				   enum hwmon_sensor_types type, u32 attr,
> +				   int channel, const char **str)
> +{
> +	struct macsmc_hwmon *hwmon = dev_get_drvdata(dev);
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		if (channel >= hwmon->temp.count)
> +			return -EINVAL;

Wrong. Such channels should not be instantiated. It is completely
unacceptable for the "sensors" command to report such errors.
Also more below on the use of -EINVAL when readin values.

> +		*str = hwmon->temp.sensors[channel].label;
> +		break;
> +	case hwmon_in:
> +		if (channel >= hwmon->volt.count)
> +			return -EINVAL;
> +		*str = hwmon->volt.sensors[channel].label;
> +		break;
> +	case hwmon_curr:
> +		if (channel >= hwmon->curr.count)
> +			return -EINVAL;
> +		*str = hwmon->curr.sensors[channel].label;
> +		break;
> +	case hwmon_power:
> +		if (channel >= hwmon->power.count)
> +			return -EINVAL;
> +		*str = hwmon->power.sensors[channel].label;
> +		break;
> +	case hwmon_fan:
> +		if (channel >= hwmon->fan.count)
> +			return -EINVAL;
> +		*str = hwmon->fan.fans[channel].label;
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * A number of sensors report data in a 48.16 fixed-point decimal format that is
> + * not used by any other function of the SMC.
> + */
> +static int macsmc_hwmon_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;
> +
> +	*p = mult_frac(val, scale, 65536);
> +
> +	return 0;
> +}
> +
> +/*
> + * Many sensors report their data as IEEE-754 floats. No other SMC function uses
> + * them.
> + */
> +static int macsmc_hwmon_read_f32_scaled(struct apple_smc *smc, smc_key key,
> +					int *p, int scale)
> +{
> +	u32 fval;
> +	u64 val;
> +	int ret, exp;
> +
> +	ret = apple_smc_read_u32(smc, key, &fval);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = ((u64)((fval & FLT_MANT_MASK) | BIT(23)));
> +	exp = ((fval >> 23) & 0xff) - FLT_EXP_BIAS - FLT_MANT_BIAS;
> +	if (scale < 0) {
> +		val <<= 32;
> +		exp -= 32;
> +		val /= -scale;
> +	} else {
> +		val *= scale;
> +	}
> +
> +	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;
> +
> +	if (fval & FLT_SIGN_MASK) {
> +		if (val > (-(s64)INT_MIN))
> +			*p = INT_MIN;
> +		else
> +			*p = -val;
> +	} else {
> +		if (val > INT_MAX)
> +			*p = INT_MAX;
> +		else
> +			*p = val;
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * The SMC has keys of multiple types, denoted by a FourCC of the same format
> + * as the key ID. We don't know what data type a key encodes until we poke at it.
> + */
> +static int macsmc_hwmon_read_key(struct apple_smc *smc,
> +				 struct macsmc_hwmon_sensor *sensor, int scale,
> +				 long *val)
> +{
> +	int ret;
> +
> +	switch (sensor->info.type_code) {
> +	/* 32-bit IEEE 754 float */
> +	case _SMC_KEY("flt "): {
> +		u32 flt_ = 0;
> +
> +		ret = macsmc_hwmon_read_f32_scaled(smc, sensor->macsmc_key,
> +						   &flt_, scale);
		if (ret)
			return ret;

> +		*val = flt_;
> +		break;
> +	}
> +	/* 48.16 fixed point decimal */
> +	case _SMC_KEY("ioft"): {
> +		u64 ioft = 0;
> +
> +		ret = macsmc_hwmon_read_ioft_scaled(smc, sensor->macsmc_key,
> +						    &ioft, scale);
		if (ret)
			return ret;

> +		*val = (long)ioft;
> +		break;
> +	}
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (ret)
> +		return -EINVAL;

Drop

> +
> +	return 0;
> +}
> +
> +static int macsmc_hwmon_write_f32_scaled(struct apple_smc *smc, smc_key key,
> +					 int value, int scale)
> +{
> +	u64 val;
> +	u32 fval = 0;
> +	int exp, neg;
> +
> +	val = abs(value);
> +	neg = val != value;
> +
> +	if (scale > 1) {
> +		val <<= 32;
> +		exp = 32;
> +		val /= scale;
> +	} else if (scale < 1) {
> +		val *= -scale;
> +	}
> +
> +	if (val) {
> +		int msb = __fls(val) - exp;
> +
> +		if (msb > 23) {
> +			val >>= msb - 23;
> +			exp -= msb - 23;
> +		} else if (msb < 23) {
> +			val <<= 23 - msb;
> +			exp += msb;
> +		}
> +
> +		fval = FIELD_PREP(FLT_SIGN_MASK, neg) |
> +		       FIELD_PREP(FLT_EXP_MASK, exp + FLT_EXP_BIAS) |
> +		       FIELD_PREP(FLT_MANT_MASK, val);
> +	}
> +
> +	return apple_smc_write_u32(smc, key, fval);
> +}
> +
> +static int macsmc_hwmon_write_key(struct apple_smc *smc,
> +				  struct macsmc_hwmon_sensor *sensor, long val,
> +				  int scale)
> +{
> +	switch (sensor->info.type_code) {
> +	/* 32-bit IEEE 754 float */
> +	case _SMC_KEY("flt "):
> +		return macsmc_hwmon_write_f32_scaled(smc, sensor->macsmc_key,
> +						     val, scale);
> +	/* unsigned 8-bit integer */
> +	case _SMC_KEY("ui8 "):
> +		return apple_smc_write_u8(smc, sensor->macsmc_key, val);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int macsmc_hwmon_read_fan(struct macsmc_hwmon *hwmon, u32 attr, int chan,
> +				 long *val)
> +{
> +	if (!(hwmon->fan.fans[chan].attrs & BIT(attr)))
> +		return -EINVAL;

This is wrong. If the fan does not exist, the is_visible function should
have dropped the attribute. Also, EINVAL is "invalid argument" which is
just impossible when _reading_ a value from the kernel.

> +
> +	switch (attr) {
> +	case hwmon_fan_input:
> +		return macsmc_hwmon_read_key(hwmon->smc,
> +					     &hwmon->fan.fans[chan].now, 1, val);
> +	case hwmon_fan_min:
> +		return macsmc_hwmon_read_key(hwmon->smc,
> +					     &hwmon->fan.fans[chan].min, 1, val);
> +	case hwmon_fan_max:
> +		return macsmc_hwmon_read_key(hwmon->smc,
> +					     &hwmon->fan.fans[chan].max, 1, val);
> +	case hwmon_fan_target:
> +		return macsmc_hwmon_read_key(hwmon->smc,
> +					     &hwmon->fan.fans[chan].set, 1, val);
> +	default:
> +		return -EINVAL;

As above.

> +	}
> +}
> +
> +static int macsmc_hwmon_write_fan(struct device *dev, u32 attr, int channel,
> +				  long val)
> +{
> +	struct macsmc_hwmon *hwmon = dev_get_drvdata(dev);
> +	long min, max;
> +	int ret;
> +
> +	if (!fan_control || hwmon->fan.fans[channel].mode.macsmc_key == 0)
> +		return -EOPNOTSUPP;
> +
> +	if (channel >= hwmon->fan.count ||
> +	    !(hwmon->fan.fans[channel].attrs & BIT(attr)) ||
> +	    attr != hwmon_fan_target)
> +		return -EINVAL;

And again.

> +
> +	/*
> +	 * The SMC does no sanity checks on requested fan speeds, so we need to.
> +	 */
> +	ret = macsmc_hwmon_read_key(hwmon->smc, &hwmon->fan.fans[channel].min,
> +				    1, &min);
> +	if (ret)
> +		return ret;
> +
> +	ret = macsmc_hwmon_read_key(hwmon->smc, &hwmon->fan.fans[channel].max,
> +				    1, &max);
> +	if (ret)
> +		return ret;
> +
> +	if (val >= min && val <= max) {
> +		if (!hwmon->fan.fans[channel].manual) {
> +			/* Write 1 to mode key for manual control */
> +			ret = macsmc_hwmon_write_key(hwmon->smc,
> +						     &hwmon->fan.fans[channel].mode, 1,
> +						     1);
> +			if (ret < 0)
> +				return ret;
> +
> +			hwmon->fan.fans[channel].manual = true;
> +		}
> +		return macsmc_hwmon_write_key(hwmon->smc,
> +					      &hwmon->fan.fans[channel].set, val, 1);
> +	} else if (!val) {
> +		if (hwmon->fan.fans[channel].manual) {
> +			ret = macsmc_hwmon_write_key(hwmon->smc,
> +						     &hwmon->fan.fans[channel].mode, 0, 1);
> +			if (ret < 0)
> +				return ret;
> +
> +			hwmon->fan.fans[channel].manual = false;
> +		}
> +	} else {
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int macsmc_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> +			     u32 attr, int channel, long *val)
> +{
> +	struct macsmc_hwmon *hwmon = dev_get_drvdata(dev);
> +	int ret = 0;
> +
> +	switch (type) {
> +	case hwmon_temp:
> +		ret = macsmc_hwmon_read_key(hwmon->smc,
> +					    &hwmon->temp.sensors[channel], 1000, val);
> +		break;
> +	case hwmon_in:
> +		ret = macsmc_hwmon_read_key(hwmon->smc,
> +					    &hwmon->volt.sensors[channel], 1000, val);
> +		break;
> +	case hwmon_curr:
> +		ret = macsmc_hwmon_read_key(hwmon->smc,
> +					    &hwmon->curr.sensors[channel], 1000, val);
> +		break;
> +	case hwmon_power:
> +		/* SMC returns power in Watts with acceptable precision to scale to uW */
> +		ret = macsmc_hwmon_read_key(hwmon->smc,
> +					    &hwmon->power.sensors[channel],
> +					    1000000, val);
> +		break;
> +	case hwmon_fan:
> +		ret = macsmc_hwmon_read_fan(hwmon, attr, channel, val);
> +		break;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return ret;
> +}
> +
> +static int macsmc_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
> +			      u32 attr, int channel, long val)
> +{
> +	switch (type) {
> +	case hwmon_fan:
> +		return macsmc_hwmon_write_fan(dev, attr, channel, val);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static umode_t macsmc_hwmon_fan_is_visible(const void *data, u32 attr,
> +					   int channel)
> +{
> +	const struct macsmc_hwmon *hwmon = data;
> +
> +	if (fan_control && attr == hwmon_fan_target &&
> +	    hwmon->fan.fans[channel].mode.macsmc_key != 0)
> +		return 0644;
> +
> +	return 0444;

This should return 0 for non-existing fans.

> +}
> +
> +static umode_t macsmc_hwmon_is_visible(const void *data,
> +				       enum hwmon_sensor_types type, u32 attr,
> +				       int channel)
> +{
> +	switch (type) {
> +	case hwmon_fan:
> +		return macsmc_hwmon_fan_is_visible(data, attr, channel);
> +	default:
> +		break;
> +	}
> +
> +	return 0444;

If those attributes exist they must be supported. Otherwise return 0.

> +}
> +
> +static const struct hwmon_ops macsmc_hwmon_ops = {
> +	.is_visible = macsmc_hwmon_is_visible,
> +	.read = macsmc_hwmon_read,
> +	.read_string = macsmc_hwmon_read_label,
> +	.write = macsmc_hwmon_write,
> +};
> +
> +/*
> + * Get the key metadata, including key data type, from the SMC.
> + */
> +static int macsmc_hwmon_parse_key(struct device *dev, struct apple_smc *smc,
> +				  struct macsmc_hwmon_sensor *sensor,
> +				  const char *key)
> +{
> +	int ret;
> +
> +	ret = apple_smc_get_key_info(smc, _SMC_KEY(key), &sensor->info);
> +	if (ret) {
> +		dev_err(dev, "Failed to retrieve key info for %s\n", key);
> +		return ret;
> +	}
> +
> +	sensor->macsmc_key = _SMC_KEY(key);
> +
> +	return 0;
> +}
> +
> +/*
> + * A sensor is a single key-value pair as made available by the SMC.
> + * The devicetree gives us the SMC key ID and a friendly name where the
> + * purpose of the sensor is known.
> + */
> +static int macsmc_hwmon_create_sensor(struct device *dev, struct apple_smc *smc,
> +				      struct device_node *sensor_node,
> +				      struct macsmc_hwmon_sensor *sensor)
> +{
> +	const char *key, *label;
> +	int ret;
> +
> +	ret = of_property_read_string(sensor_node, "apple,key-id", &key);
> +	if (ret) {
> +		dev_err(dev, "Could not find apple,key-id in sensor node\n");
> +		return ret;
> +	}
> +
> +	ret = macsmc_hwmon_parse_key(dev, smc, sensor, key);
> +	if (ret)
> +		return ret;
> +
> +	ret = of_property_read_string(sensor_node, "label", &label);
> +	if (ret) {
> +		dev_err(dev, "No label found for sensor %s\n", key);
> +		return ret;
> +	}
> +
> +	strscpy_pad(sensor->label, label, sizeof(sensor->label));
> +
> +	return 0;
> +}
> +
> +/*
> + * Fan data is exposed by the SMC as multiple sensors.
> + *
> + * The devicetree schema reuses apple,key-id for the actual fan speed sensor.
> + * Min, max and target keys do not need labels, so we can reuse label
> + * for naming the entire fan.
> + */
> +static int macsmc_hwmon_create_fan(struct device *dev, struct apple_smc *smc,
> +				   struct device_node *fan_node,
> +				   struct macsmc_hwmon_fan *fan)
> +{
> +	const char *label, *now, *min, *max, *set, *mode;
> +	int ret;
> +
> +	ret = of_property_read_string(fan_node, "apple,key-id", &now);
> +	if (ret) {
> +		dev_err(dev, "apple,key-id not found in fan node!\n");
> +		return -EINVAL;

		return ret;

Never overwrite error numbers.

> +	}
> +
> +	ret = macsmc_hwmon_parse_key(dev, smc, &fan->now, now);
> +	if (ret)
> +		return ret;
> +
> +	ret = of_property_read_string(fan_node, "label", &label);
> +	if (ret) {
> +		dev_err(dev, "No label found for fan %s\n", now);
> +		return ret;
> +	}
> +
> +	strscpy_pad(fan->label, label, sizeof(fan->label));
> +
> +	fan->attrs = HWMON_F_LABEL | HWMON_F_INPUT;
> +
> +	/* The following keys are not required to simply monitor fan speed */
> +	if (!of_property_read_string(fan_node, "apple,fan-minimum", &min)) {
> +		ret = macsmc_hwmon_parse_key(dev, smc, &fan->min, min);
> +		if (ret)
> +			return ret;
> +
> +		fan->attrs |= HWMON_F_MIN;
> +	}
> +
> +	if (!of_property_read_string(fan_node, "apple,fan-maximum", &max)) {
> +		ret = macsmc_hwmon_parse_key(dev, smc, &fan->max, max);
> +		if (ret)
> +			return ret;
> +
> +		fan->attrs |= HWMON_F_MAX;
> +	}
> +
> +	if (!of_property_read_string(fan_node, "apple,fan-target", &set)) {
> +		ret = macsmc_hwmon_parse_key(dev, smc, &fan->set, set);
> +		if (ret)
> +			return ret;
> +
> +		fan->attrs |= HWMON_F_TARGET;
> +	}
> +
> +	if (!of_property_read_string(fan_node, "apple,fan-mode", &mode)) {
> +		ret = macsmc_hwmon_parse_key(dev, smc, &fan->mode, mode);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* Initialise fan control mode to automatic */
> +	fan->manual = false;
> +
> +	return 0;
> +}
> +
> +static int macsmc_hwmon_populate_sensors(struct macsmc_hwmon *hwmon,
> +					 struct device_node *hwmon_node)
> +{
> +	struct device_node *key_node __maybe_unused;
> +	u32 n_current = 0, n_fan = 0, n_power = 0, n_temperature = 0, n_voltage = 0;
> +
> +	for_each_child_of_node_with_prefix(hwmon_node, key_node, "current-") {
> +		n_current++;
> +	}
> +
> +	if (n_current) {
> +		hwmon->curr.sensors = devm_kcalloc(hwmon->dev, n_current,
> +						   sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
> +		if (!hwmon->curr.sensors)
> +			return -ENOMEM;
> +
> +		for_each_child_of_node_with_prefix(hwmon_node, key_node, "current-") {
> +			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
> +							&hwmon->curr.sensors[hwmon->curr.count]))
> +				hwmon->curr.count++;
> +		}
> +	}
> +
> +	for_each_child_of_node_with_prefix(hwmon_node, key_node, "fan-") {
> +		n_fan++;
> +	}
> +
> +	if (n_fan) {
> +		hwmon->fan.fans = devm_kcalloc(hwmon->dev, n_fan,
> +					       sizeof(struct macsmc_hwmon_fan), GFP_KERNEL);
> +		if (!hwmon->fan.fans)
> +			return -ENOMEM;
> +
> +		for_each_child_of_node_with_prefix(hwmon_node, key_node, "fan-") {
> +			if (!macsmc_hwmon_create_fan(hwmon->dev, hwmon->smc, key_node,
> +						     &hwmon->fan.fans[hwmon->fan.count]))
> +				hwmon->fan.count++;
> +		}
> +	}
> +
> +	for_each_child_of_node_with_prefix(hwmon_node, key_node, "power-") {
> +		n_power++;
> +	}
> +
> +	if (n_power) {
> +		hwmon->power.sensors = devm_kcalloc(hwmon->dev, n_power,
> +						    sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
> +		if (!hwmon->power.sensors)
> +			return -ENOMEM;
> +
> +		for_each_child_of_node_with_prefix(hwmon_node, key_node, "power-") {
> +			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
> +							&hwmon->power.sensors[hwmon->power.count]))
> +				hwmon->power.count++;
> +		}
> +	}
> +
> +	for_each_child_of_node_with_prefix(hwmon_node, key_node, "temperature-") {
> +		n_temperature++;
> +	}
> +
> +	if (n_temperature) {
> +		hwmon->temp.sensors = devm_kcalloc(hwmon->dev, n_temperature,
> +						   sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
> +		if (!hwmon->temp.sensors)
> +			return -ENOMEM;
> +
> +		for_each_child_of_node_with_prefix(hwmon_node, key_node, "temperature-") {
> +			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
> +							&hwmon->temp.sensors[hwmon->temp.count]))
> +				hwmon->temp.count++;
> +		}
> +	}
> +
> +	for_each_child_of_node_with_prefix(hwmon_node, key_node, "voltage-") {
> +		n_voltage++;
> +	}
> +
> +	if (n_voltage) {
> +		hwmon->volt.sensors = devm_kcalloc(hwmon->dev, n_voltage,
> +						   sizeof(struct macsmc_hwmon_sensor), GFP_KERNEL);
> +		if (!hwmon->volt.sensors)
> +			return -ENOMEM;
> +
> +		for_each_child_of_node_with_prefix(hwmon_node, key_node, "volt-") {
> +			if (!macsmc_hwmon_create_sensor(hwmon->dev, hwmon->smc, key_node,
> +							&hwmon->volt.sensors[hwmon->volt.count]))
> +				hwmon->volt.count++;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/* Create NULL-terminated config arrays */
> +static void macsmc_hwmon_populate_configs(u32 *configs, u32 num_keys, u32 flags)
> +{
> +	int idx;
> +
> +	for (idx = 0; idx < num_keys; idx++)
> +		configs[idx] = flags;
> +}
> +
> +static void macsmc_hwmon_populate_fan_configs(u32 *configs, u32 num_keys,
> +					      struct macsmc_hwmon_fans *fans)
> +{
> +	int idx;
> +
> +	for (idx = 0; idx < num_keys; idx++)
> +		configs[idx] = fans->fans[idx].attrs;
> +}
> +
> +static const struct hwmon_channel_info *const macsmc_chip_channel_info =
> +	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ);
> +
> +static int macsmc_hwmon_create_infos(struct macsmc_hwmon *hwmon)
> +{
> +	struct hwmon_channel_info *channel_info;
> +	int i = 0;
> +
> +	/* chip */
> +	hwmon->channel_infos[i++] = macsmc_chip_channel_info;
> +
> +	if (hwmon->curr.count) {
> +		channel_info = &hwmon->curr.channel_info;
> +		channel_info->type = hwmon_curr;
> +		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->curr.count + 1,
> +						    sizeof(u32), GFP_KERNEL);
> +		if (!channel_info->config)
> +			return -ENOMEM;
> +
> +		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
> +					      hwmon->curr.count,
> +					      (HWMON_C_INPUT | HWMON_C_LABEL));

Unnecessary ()

> +		hwmon->channel_infos[i++] = channel_info;
> +	}
> +
> +	if (hwmon->fan.count) {
> +		channel_info = &hwmon->fan.channel_info;
> +		channel_info->type = hwmon_fan;
> +		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->fan.count + 1,
> +						    sizeof(u32), GFP_KERNEL);
> +		if (!channel_info->config)
> +			return -ENOMEM;
> +
> +		macsmc_hwmon_populate_fan_configs((u32 *)channel_info->config,
> +						  hwmon->fan.count,
> +						  &hwmon->fan);
> +		hwmon->channel_infos[i++] = channel_info;
> +	}
> +
> +	if (hwmon->power.count) {
> +		channel_info = &hwmon->power.channel_info;
> +		channel_info->type = hwmon_power;
> +		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->power.count + 1,
> +						    sizeof(u32), GFP_KERNEL);
> +		if (!channel_info->config)
> +			return -ENOMEM;
> +
> +		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
> +					      hwmon->power.count,
> +					      (HWMON_P_INPUT | HWMON_P_LABEL));

Unnecessary (). Drop everywhere.

> +		hwmon->channel_infos[i++] = channel_info;
> +	}
> +
> +	if (hwmon->temp.count) {
> +		channel_info = &hwmon->temp.channel_info;
> +		channel_info->type = hwmon_temp;
> +		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->temp.count + 1,
> +						    sizeof(u32), GFP_KERNEL);
> +		if (!channel_info->config)
> +			return -ENOMEM;
> +
> +		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
> +					      hwmon->temp.count,
> +					      (HWMON_T_INPUT | HWMON_T_LABEL));
> +		hwmon->channel_infos[i++] = channel_info;
> +	}
> +
> +	if (hwmon->volt.count) {
> +		channel_info = &hwmon->volt.channel_info;
> +		channel_info->type = hwmon_in;
> +		channel_info->config = devm_kcalloc(hwmon->dev, hwmon->volt.count + 1,
> +						    sizeof(u32), GFP_KERNEL);
> +		if (!channel_info->config)
> +			return -ENOMEM;
> +
> +		macsmc_hwmon_populate_configs((u32 *)channel_info->config,
> +					      hwmon->volt.count,
> +					      (HWMON_I_INPUT | HWMON_I_LABEL));
> +		hwmon->channel_infos[i++] = channel_info;
> +	}
> +
> +	return 0;
> +}
> +
> +static int macsmc_hwmon_probe(struct platform_device *pdev)
> +{
> +	struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
> +	struct macsmc_hwmon *hwmon;
> +	int ret;
> +
> +	/*
> +	 * The MFD driver will try to probe us unconditionally. Some devices
> +	 * with the SMC do not have hwmon capabilities. Only probe if we have
> +	 * a hwmon node.
> +	 */
> +	if (!pdev->dev.of_node)
> +		return -ENODEV;
> +
> +	hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon),
> +			     GFP_KERNEL);
> +	if (!hwmon)
> +		return -ENOMEM;
> +
> +	hwmon->dev = &pdev->dev;
> +	hwmon->smc = smc;
> +
> +	ret = macsmc_hwmon_populate_sensors(hwmon, hwmon->dev->of_node);
> +	if (ret) {
> +		dev_err(hwmon->dev, "Could not populate keys!\n");
> +		return ret;
> +	}
> +
> +	if (!hwmon->curr.count && !hwmon->fan.count &&
> +	    !hwmon->power.count && !hwmon->temp.count &&
> +	    !hwmon->volt.count) {
> +		dev_err(hwmon->dev,
> +			"No valid keys found of any supported type");
> +		return -ENODEV;
> +	}
> +
> +	ret = macsmc_hwmon_create_infos(hwmon);
> +	if (ret)
> +		return ret;
> +
> +	hwmon->chip_info.ops = &macsmc_hwmon_ops;
> +	hwmon->chip_info.info =
> +		(const struct hwmon_channel_info *const *)&hwmon->channel_infos;
> +
> +	hwmon->hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
> +								"macsmc_hwmon", hwmon,
> +								&hwmon->chip_info, NULL);
> +	if (IS_ERR(hwmon->hwmon_dev))
> +		return dev_err_probe(hwmon->dev, PTR_ERR(hwmon->hwmon_dev),
> +				     "Probing SMC hwmon device failed\n");
> +
> +	dev_info(hwmon->dev, "Registered SMC hwmon device. Sensors:");
> +	dev_info(hwmon->dev,
> +		 "Current: %d, Fans: %d, Power: %d, Temperature: %d, Voltage: %d",
> +		 hwmon->curr.count, hwmon->fan.count,
> +		 hwmon->power.count, hwmon->temp.count,
> +		 hwmon->volt.count);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id macsmc_hwmon_of_table[] = {
> +	{ .compatible = "apple,smc-hwmon" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, macsmc_hwmon_of_table);
> +
> +static struct platform_driver macsmc_hwmon_driver = {
> +	.probe = macsmc_hwmon_probe,
> +	.driver = {
> +		.name = "macsmc_hwmon",
> +		.of_match_table = macsmc_hwmon_of_table,
> +	},
> +};
> +module_platform_driver(macsmc_hwmon_driver);
> +
> +MODULE_DESCRIPTION("Apple Silicon SMC hwmon driver");
> +MODULE_AUTHOR("James Calligeros <jcalligeros99@gmail.com>");
> +MODULE_LICENSE("Dual MIT/GPL");
> +MODULE_ALIAS("platform:macsmc_hwmon");

Re: [PATCH v2 07/11] input: macsmc-hid: New driver to handle the Apple Mac SMC buttons/lid

[Dmitry Torokhov]

Hi James,

On Wed, Aug 27, 2025 at 09:22:41PM +1000, James Calligeros wrote:
> +static void macsmc_hid_event_button(struct macsmc_hid *smchid, unsigned long event)
> +{
> +	u8 button = (event >> 8) & 0xff;
> +	u8 state = !!(event & 0xff);
> +
> +	switch (button) {
> +	case BTN_POWER:
> +	case BTN_TOUCHID:
> +		if (smchid->wakeup_mode) {
> +			if (state)
> +				pm_wakeup_hard_event(smchid->dev);
> +		} else {
> +			input_report_key(smchid->input, KEY_POWER, state);
> +			input_sync(smchid->input);
> +		}

I believe you should be using pm_wakeup_event() in all cases so that
pressing power would interrupt suspend even if resume() handler has not
been run yet. Also I do not think suppressing KEY_POWER is needed.
Userspace should be smart and decide whether to shutdown the system or
not when receiving KEY_POWER depending on the overall system state.

...
> +
> +static int macsmc_hid_probe(struct platform_device *pdev)
> +{
> +	struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
> +	struct macsmc_hid *smchid;
> +	bool have_lid, have_power;
> +	int ret;

	int error;

> +
> +	/* Bail early if this SMC neither supports power button nor lid events */
> +	have_lid = apple_smc_key_exists(smc, SMC_KEY(MSLD));
> +	have_power = apple_smc_key_exists(smc, SMC_KEY(bHLD));
> +	if (!have_lid && !have_power)
> +		return -ENODEV;
> +
> +	smchid = devm_kzalloc(&pdev->dev, sizeof(*smchid), GFP_KERNEL);
> +	if (!smchid)
> +		return -ENOMEM;
> +
> +	smchid->dev = &pdev->dev;
> +	smchid->smc = smc;
> +	platform_set_drvdata(pdev, smchid);
> +
> +	smchid->input = devm_input_allocate_device(&pdev->dev);
> +	if (!smchid->input)
> +		return -ENOMEM;
> +
> +	smchid->input->phys = "macsmc-hid (0)";
> +	smchid->input->name = "Apple SMC power/lid events";
> +
> +	if (have_lid)
> +		input_set_capability(smchid->input, EV_SW, SW_LID);
> +	if (have_power)
> +		input_set_capability(smchid->input, EV_KEY, KEY_POWER);
> +
> +	ret = input_register_device(smchid->input);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Failed to register input device: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (have_lid) {
> +		u8 val;
> +
> +		ret = apple_smc_read_u8(smc, SMC_KEY(MSLD), &val);
> +		if (ret < 0)
> +			dev_warn(&pdev->dev, "Failed to read initial lid state\n");
> +		else
> +			input_report_switch(smchid->input, SW_LID, val);
> +	}
> +
> +	if (have_power) {
> +		u32 val;
> +
> +		ret = apple_smc_read_u32(smc, SMC_KEY(bHLD), &val);
> +		if (ret < 0)
> +			dev_warn(&pdev->dev, "Failed to read initial power button state\n");
> +		else
> +			input_report_key(smchid->input, KEY_POWER, val & 1);
> +	}

Since you are doing this to seed initial switch/button state I would do
this before registering input device (this is safe to do so).

Thanks.

-- 
Dmitry

Re: [PATCH v2 02/11] dt-bindings: hwmon: Add Apple System Management Controller hwmon schema

[Rob Herring]

On Wed, Aug 27, 2025 at 09:22:36PM +1000, James Calligeros wrote:
> Apple Silicon devices integrate a vast array of sensors, monitoring
> current, power, temperature, and voltage across almost every part of
> the system. The sensors themselves are all connected to the System
> Management Controller (SMC). The SMC firmware exposes the data
> reported by these sensors via its standard FourCC-based key-value
> API. The SMC is also responsible for monitoring and controlling any
> fans connected to the system, exposing them in the same way.
> 
> For reasons known only to Apple, each device exposes its sensors with
> an almost totally unique set of keys. This is true even for devices
> which share an SoC. An M1 Mac mini, for example, will report its core
> temperatures on different keys to an M1 MacBook Pro. Worse still, the
> SMC does not provide a way to enumerate the available keys at runtime,
> nor do the keys follow any sort of reasonable or consistent naming
> rules that could be used to deduce their purpose. We must therefore
> know which keys are present on any given device, and which function
> they serve, ahead of time.
> 
> Add a schema so that we can describe the available sensors for a given
> Apple Silicon device in the Devicetree.
> 
> Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
> ---
>  .../bindings/hwmon/apple,smc-hwmon.yaml  | 132 +++++++++++++++++++++++++
>  .../bindings/mfd/apple,smc.yaml          |  36 +++++++
>  MAINTAINERS                              |   1 +
>  3 files changed, 169 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml b/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..08cc4f55f3a41ca8b3b428088f96240266fa42e8
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
> @@ -0,0 +1,132 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/apple,smc-hwmon.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Apple SMC Hardware Monitoring
> +
> +description:
> +  Apple's System Management Controller (SMC) exposes a vast array of
> +  hardware monitoring sensors, including temperature probes, current and
> +  voltage sense, power meters, and fan speeds. It also provides endpoints
> +  to manually control the speed of each fan individually. Each Apple
> +  Silicon device exposes a different set of endpoints via SMC keys. This
> +  is true even when two machines share an SoC. The CPU core temperature
> +  sensor keys on an M1 Mac mini are different to those on an M1 MacBook
> +  Pro, for example.
> +
> +maintainers:
> +  - James Calligeros <jcalligeros99@gmail.com>
> +
> +definitions:

$defs

definitions was convention. $defs is in json-schema spec now.

> +  apple,key-id:
> +    $ref: /schemas/types.yaml#/definitions/string
> +    pattern: "^[A-Za-z0-9]{4}$"
> +    description: The SMC FourCC key of the desired sensor.
> +      Must match the node's suffix.
> +
> +  label:
> +    description: Human-readable name for the sensor
> +
> +properties:
> +  compatible:
> +    const: apple,smc-hwmon
> +
> +patternProperties:
> +  "^current-[A-Za-z0-9]{4}$":
> +    type: object
> +    additionalProperties: false
> +
> +    properties:
> +      apple,key-id:
> +        $ref: "#/definitions/apple,key-id"
> +
> +      label:
> +        $ref: "#/definitions/label"
> +
> +    required:
> +      - apple,key-id
> +      - label

This should be something like this:

"^current-[A-Za-z0-9]{4}$":
  $ref: "#/$defs/sensor"
  unevaluatedProperties: false

With the $defs/sensor being:

$defs:
  sensor:
    type: object
    
    properties:
      apple,key-id:
        $ref: /schemas/types.yaml#/definitions/string
        pattern: "^[A-Za-z0-9]{4}$"
        description: 
          The SMC FourCC key of the desired sensor. Must match the 
          node's suffix.

      label:
        description: Human-readable name for the sensor

    required:
      - apple,key-id
      - label

Though in general, 'label' should never be required being just for human 
convenience.

> +
> +  "^fan-[A-Za-z0-9]{4}$":
> +    type: object
> +    additionalProperties: false

And this one the same as above, but with the additional fan properties 
listed here.

> +
> +    properties:
> +      apple,key-id:
> +        $ref: "#/definitions/apple,key-id"
> +
> +      apple,fan-minimum:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        pattern: "^[A-Za-z0-9]{4}$"
> +        description: SMC key containing the fan's minimum speed
> +
> +      apple,fan-maximum:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        pattern: "^[A-Za-z0-9]{4}$"
> +        description: SMC key containing the fan's maximum speed
> +
> +      apple,fan-target:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        pattern: "^[A-Za-z0-9]{4}$"
> +        description: Writeable endpoint for setting desired fan speed
> +
> +      apple,fan-mode:
> +        $ref: /schemas/types.yaml#/definitions/string
> +        pattern: "^[A-Za-z0-9]{4}$"
> +        description: Writeable key to enable/disable manual fan control
> +
> +      label:
> +        $ref: "#/definitions/label"
> +
> +    required:
> +      - apple,key-id
> +      - label
> +
> +  "^power-[A-Za-z0-9]{4}$":
> +    type: object
> +    additionalProperties: false
> +
> +    properties:
> +      apple,key-id:
> +        $ref: "#/definitions/apple,key-id"
> +
> +      label:
> +        $ref: "#/definitions/label"
> +
> +    required:
> +      - apple,key-id
> +      - label
> +
> +  "^temperature-[A-Za-z0-9]{4}$":
> +    type: object
> +    additionalProperties: false
> +
> +    properties:
> +      apple,key-id:
> +        $ref: "#/definitions/apple,key-id"
> +
> +      label:
> +        $ref: "#/definitions/label"
> +
> +    required:
> +      - apple,key-id
> +      - label
> +
> +  "^voltage-[A-Za-z0-9]{4}$":
> +    type: object
> +    additionalProperties: false
> +
> +    properties:
> +      apple,key-id:
> +        $ref: "#/definitions/apple,key-id"
> +
> +      label:
> +        $ref: "#/definitions/label"
> +
> +    required:
> +      - apple,key-id
> +      - label
> +
> +additionalProperties: false