mfd: macsmc: Support T6050 power and pcIO consumers

Documentation/devicetree/bindings/gpio/apple,smc-pcio-gpio.yaml

@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/apple,smc-pcio-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SMC pcIO output GPIOs
+
+maintainers:
+  - Dj <hey@djdev.me>
+
+description: |
+  The writable eight-byte pcIO SMC key controls outputs through board
+  command templates. Each template has its low 16 bits clear; the driver
+  inserts a boolean output level and sends the little-endian command.
+  Input reads and mode changes are not supported by this interface.
+
+properties:
+  compatible:
+    const: apple,smc-pcio-gpio
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  apple,output-commands:
+    $ref: /schemas/types.yaml#/definitions/uint64-array
+    minItems: 1
+    maxItems: 64
+    uniqueItems: true
+    description: Unique command templates with low 16 bits clear, in GPIO order
+
+required:
+  - compatible
+  - gpio-controller
+  - '#gpio-cells'
+  - apple,output-commands
+
+additionalProperties: false

Documentation/devicetree/bindings/mfd/apple,smc.yaml

@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) AND GPL-2.0-only
 %YAML 1.2
 ---
 $id: http://devicetree.org/schemas/mfd/apple,smc.yaml#
@@ -16,6 +16,7 @@ description:
 properties:
   compatible:
     oneOf:
+      - const: apple,t6050-smc
       - items:
           - enum:
               - apple,t6020-smc
@@ -47,7 +48,9 @@ properties:
     maxItems: 1
 
   gpio:
-    $ref: /schemas/gpio/apple,smc-gpio.yaml
+    oneOf:
+      - $ref: /schemas/gpio/apple,smc-gpio.yaml
+      - $ref: /schemas/gpio/apple,smc-pcio-gpio.yaml
 
   reboot:
     $ref: /schemas/power/reset/apple,smc-reboot.yaml

drivers/gpio/gpio-macsmc.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0-only OR MIT
+// SPDX-License-Identifier: (GPL-2.0-only OR MIT) AND GPL-2.0-only
 /*
  * Apple SMC GPIO driver
  * Copyright The Asahi Linux Contributors
@@ -15,6 +15,7 @@
 #include <linux/mfd/macsmc.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/unaligned.h>
 
 #define MAX_GPIO 64
 
@@ -101,6 +102,7 @@ struct macsmc_gpio {
 	struct apple_smc *smc;
 	struct gpio_chip gc;
 
+	u64 *output_commands;
 	int first_index;
 	smc_key base_key;
 
@@ -342,6 +344,72 @@ static int macsmc_gpio_init_valid_mask(struct gpio_chip *gc,
 	return 0;
 }
 
+/* Each DT template identifies one output; its low 16 bits carry the value. */
+static int macsmc_pcio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	struct macsmc_gpio *smcgp = gpiochip_get_data(gc);
+	u8 command[8];
+	int ret;
+
+	put_unaligned_le64(smcgp->output_commands[offset] | !!value, command);
+	ret = apple_smc_write(smcgp->smc, SMC_KEY(pcIO), command, sizeof(command));
+	/* SMC writes return status, not a byte count. */
+	return ret < 0 ? ret : 0;
+}
+
+static int macsmc_pcio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	/* The native output command has no established input/readback operation. */
+	return -EOPNOTSUPP;
+}
+
+static int macsmc_pcio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int macsmc_pcio_probe(struct macsmc_gpio *smcgp)
+{
+	struct device *dev = smcgp->dev;
+	struct apple_smc_key_info info;
+	int count, ret;
+
+	ret = apple_smc_get_key_info(smcgp->smc, SMC_KEY(pcIO), &info);
+	if (ret < 0)
+		return ret;
+	if (info.size != 8 || !(info.flags & APPLE_SMC_WRITABLE))
+		return dev_err_probe(dev, -EINVAL, "pcIO is not an eight-byte output key\n");
+	count = of_property_count_u64_elems(dev->of_node, "apple,output-commands");
+	if (count <= 0 || count > MAX_GPIO)
+		return -EINVAL;
+	smcgp->output_commands = devm_kcalloc(dev, count, sizeof(u64), GFP_KERNEL);
+	if (!smcgp->output_commands)
+		return -ENOMEM;
+	ret = of_property_read_u64_array(dev->of_node, "apple,output-commands",
+					smcgp->output_commands, count);
+	if (ret)
+		return ret;
+	for (int i = 0; i < count; i++) {
+		if (smcgp->output_commands[i] & 0xffff)
+			return -EINVAL;
+		for (int j = 0; j < i; j++)
+			if (smcgp->output_commands[i] == smcgp->output_commands[j])
+				return -EINVAL;
+	}
+
+	smcgp->gc.label = "macsmc-pcio-output";
+	smcgp->gc.owner = THIS_MODULE;
+	smcgp->gc.get = macsmc_pcio_get;
+	smcgp->gc.set = macsmc_pcio_set;
+	smcgp->gc.direction_output = macsmc_pcio_set;
+	smcgp->gc.get_direction = macsmc_pcio_get_direction;
+	smcgp->gc.can_sleep = true;
+	smcgp->gc.ngpio = count;
+	smcgp->gc.base = -1;
+	smcgp->gc.parent = dev;
+	return devm_gpiochip_add_data(dev, &smcgp->gc, smcgp);
+}
+
 struct macsmc_gpio_of_match_data {
 	smc_key base_key;
 };
@@ -360,6 +428,8 @@ static int macsmc_gpio_probe(struct platform_device *pdev)
 
 	smcgp->dev = &pdev->dev;
 	smcgp->smc = smc;
+	if (device_is_compatible(&pdev->dev, "apple,smc-pcio-gpio"))
+		return macsmc_pcio_probe(smcgp);
 	smcgp->base_key = data ? data->base_key : _SMC_KEY("gP\0\0");
 	smcgp->j700_pcio = of_machine_is_compatible("apple,j700") &&
 				device_is_compatible(&pdev->dev, "apple,smc-gpio");
@@ -405,6 +475,7 @@ static const struct macsmc_gpio_of_match_data macsmc_gpio_low_data = {
 };
 
 static const struct of_device_id macsmc_gpio_of_table[] = {
+	{ .compatible = "apple,smc-pcio-gpio" },
 	{
 		.compatible = "apple,smc-gpio",
 		.data = &macsmc_gpio_up_data,

drivers/mfd/macsmc.c

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0-only OR MIT
+// SPDX-License-Identifier: (GPL-2.0-only OR MIT) AND GPL-2.0-only
 /*
  * Apple SMC (System Management Controller) MFD driver
  *
@@ -56,6 +56,16 @@ static const struct mfd_cell apple_smc_devs[] = {
 	MFD_CELL_OF("macsmc-rtc", NULL, NULL, 0, 0, "apple,smc-rtc"),
 };
 
+/* This profile exposes notifications and the explicitly described outputs. */
+static const struct mfd_cell apple_smc_t6050_devs[] = {
+	MFD_CELL_NAME("macsmc-input"),
+	MFD_CELL_NAME("macsmc-power"),
+	MFD_CELL_OF("macsmc-hwmon", NULL, NULL, 0, 0, "apple,smc-hwmon"),
+};
+
+static const struct mfd_cell apple_smc_pcio_dev =
+	MFD_CELL_OF("macsmc-gpio", NULL, NULL, 0, 0, "apple,smc-pcio-gpio");
+
 /* The second GPIO bank ('gp' keys) only exists on some SMCs. */
 static const struct mfd_cell apple_smc_low_gpio_dev =
 	MFD_CELL_OF("macsmc-low-gpio", NULL, NULL, 0, 0, "apple,smc-low-gpio");
@@ -242,8 +252,8 @@ int apple_smc_get_key_info(struct apple_smc *smc, smc_key key, struct apple_smc_
 	u8 key_info[6];
 	int ret;
 
+	/* Keep the shared reply buffer stable until its metadata is copied. */
 	guard(mutex)(&smc->mutex);
-
 	ret = apple_smc_cmd_locked(smc, SMC_MSG_GET_KEY_INFO, key, 0, 0, NULL);
 	if (ret >= 0 && info) {
 		apple_smc_read_sram(smc, key_info, sizeof(key_info));
@@ -529,12 +539,26 @@ static int apple_smc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	ret = devm_mfd_add_devices(smc->dev, PLATFORM_DEVID_NONE,
-				   apple_smc_devs, ARRAY_SIZE(apple_smc_devs),
-				   NULL, 0, NULL);
+	if (of_device_is_compatible(dev->of_node, "apple,t6050-smc"))
+		ret = devm_mfd_add_devices(smc->dev, PLATFORM_DEVID_NONE,
+					 apple_smc_t6050_devs,
+					 ARRAY_SIZE(apple_smc_t6050_devs), NULL, 0, NULL);
+	else
+		ret = devm_mfd_add_devices(smc->dev, PLATFORM_DEVID_NONE,
+					 apple_smc_devs, ARRAY_SIZE(apple_smc_devs),
+					 NULL, 0, NULL);
 	if (ret)
 		return dev_err_probe(smc->dev, ret, "Failed to register sub-devices");
 
+	np = of_get_compatible_child(dev->of_node, "apple,smc-pcio-gpio");
+	if (np) {
+		of_node_put(np);
+		ret = devm_mfd_add_devices(smc->dev, PLATFORM_DEVID_NONE,
+					 &apple_smc_pcio_dev, 1, NULL, 0, NULL);
+		if (ret)
+			return dev_err_probe(dev, ret, "Failed to register pcIO outputs\n");
+	}
+
 	/*
 	 * Register the second GPIO bank only where the device tree describes
 	 * it: the MFD core would otherwise create an unbound device and warn
@@ -554,6 +578,7 @@ static int apple_smc_probe(struct platform_device *pdev)
 }
 
 static const struct of_device_id apple_smc_of_match[] = {
+	{ .compatible = "apple,t6050-smc" },
 	{ .compatible = "apple,t8103-smc" },
 	{ .compatible = "apple,smc" },
 	{},

drivers/power/supply/macsmc-power.c

@@ -979,10 +979,34 @@ static int macsmc_power_event(struct notifier_block *nb, unsigned long event, vo
 	return NOTIFY_DONE;
 }
 
+static int macsmc_read_identity(struct apple_smc *smc, smc_key key,
+			       char *out, size_t capacity)
+{
+	struct apple_smc_key_info info;
+	int ret;
+
+	if (!capacity)
+		return -EINVAL;
+	out[0] = '\0';
+	ret = apple_smc_get_key_info(smc, key, &info);
+	if (ret < 0)
+		return ret;
+	if (!info.size || info.size >= capacity || !(info.flags & APPLE_SMC_READABLE))
+		return -EINVAL;
+	/* SMC read requests must describe this key, not the destination buffer. */
+	ret = apple_smc_read(smc, key, out, info.size);
+	if (ret != info.size) {
+		out[0] = '\0';
+		return ret < 0 ? ret : -EIO;
+	}
+	out[info.size] = '\0';
+	return 0;
+}
+
 static int macsmc_power_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct apple_smc *smc = dev_get_drvdata(pdev->dev.parent);
+	struct apple_smc *smc;
 	struct power_supply_config psy_cfg = {};
 	struct apple_smc_key_info info;
 	struct macsmc_power *power;
@@ -995,6 +1019,9 @@ static int macsmc_power_probe(struct platform_device *pdev)
 	enum power_supply_property *props;
 	size_t nprops;
 
+	if (!dev->parent)
+		return dev_err_probe(dev, -ENODEV, "Missing SMC parent\n");
+	smc = dev_get_drvdata(dev->parent);
 	if (!smc)
 		return -ENODEV;
 
@@ -1108,17 +1135,22 @@ static int macsmc_power_probe(struct platform_device *pdev)
 				     of_machine_is_compatible("apple,j700");
 		power->status_from_current = of_machine_is_compatible("apple,j700");
 
-		/* Reset "Optimised Battery Charging" flags to default state */
-		if (power->has_chte)
-			apple_smc_write_u32(smc, SMC_KEY(CHTE), 0);
-		else if (power->has_ch0c)
-			apple_smc_write_u8(smc, SMC_KEY(CH0C), 0);
-
-		if (power->has_ch0i)
-			apple_smc_write_u8(smc, SMC_KEY(CH0I), 0);
-
-		apple_smc_write_u8(smc, SMC_KEY(CH0K), 0);
-		apple_smc_write_u8(smc, SMC_KEY(CH0B), 0);
+		/* T6050 telemetry discovery must preserve firmware charge policy.
+		 * Do not reset charging controls merely to publish the battery.
+		 */
+		if (!of_device_is_compatible(dev->parent->of_node, "apple,t6050-smc")) {
+			/* Reset "Optimised Battery Charging" flags to default state. */
+			if (power->has_chte)
+				apple_smc_write_u32(smc, SMC_KEY(CHTE), 0);
+			else if (power->has_ch0c)
+				apple_smc_write_u8(smc, SMC_KEY(CH0C), 0);
+
+			if (power->has_ch0i)
+				apple_smc_write_u8(smc, SMC_KEY(CH0I), 0);
+
+			apple_smc_write_u8(smc, SMC_KEY(CH0K), 0);
+			apple_smc_write_u8(smc, SMC_KEY(CH0B), 0);
+		}
 
 		/* Detect charge limit method (CHWA vs CHLS) */
 		if (apple_smc_read_flag(power->smc, SMC_KEY(CHWA), &flag) == 0)
@@ -1150,12 +1182,12 @@ static int macsmc_power_probe(struct platform_device *pdev)
 		power->batt_desc.num_properties = nprops;
 
 		/* Fetch identity strings */
-		apple_smc_read(smc, SMC_KEY(BMDN), power->model_name,
-			       sizeof(power->model_name) - 1);
-		apple_smc_read(smc, SMC_KEY(BMSN), power->serial_number,
-			       sizeof(power->serial_number) - 1);
-		apple_smc_read(smc, SMC_KEY(BMDT), power->mfg_date,
-			       sizeof(power->mfg_date) - 1);
+		macsmc_read_identity(smc, SMC_KEY(BMDN), power->model_name,
+				     sizeof(power->model_name));
+		macsmc_read_identity(smc, SMC_KEY(BMSN), power->serial_number,
+				     sizeof(power->serial_number));
+		macsmc_read_identity(smc, SMC_KEY(BMDT), power->mfg_date,
+				     sizeof(power->mfg_date));
 
 		apple_smc_read_u8(power->smc, SMC_KEY(BNCB), &power->num_cells);
 		power->nominal_voltage_mv = MACSMC_NOMINAL_CELL_VOLTAGE_MV * power->num_cells;

tools/testing/selftests/aurora-apif/smc_charge_policy.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+"""Ensure T6050 battery discovery cannot reset charging policy."""
+from pathlib import Path
+import subprocess, tempfile
+from common import block
+
+ROOT=Path(__file__).resolve().parents[4]
+source=(ROOT/'drivers/power/supply/macsmc-power.c').read_text()
+guarded=block(source,r'^\t\tif \(!of_device_is_compatible\(dev->parent->of_node, "apple,t6050-smc"\)\)')
+probe=block(source,r'^static int macsmc_power_probe\(')
+assert probe.count('apple_smc_write_')==guarded.count('apple_smc_write_')==5
+program=r'''
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <string.h>
+struct device { struct device *parent; bool *of_node; };
+struct macsmc_power { bool has_chte,has_ch0c,has_ch0i; };
+static int calls;
+static bool of_device_is_compatible(bool *node,const char *name){assert(!strcmp(name,"apple,t6050-smc"));return *node;}
+#define SMC_KEY(k) #k
+static void apple_smc_write_u32(void *smc,const char *key,uint32_t value){(void)smc;assert(value==0);assert(!strcmp(key,"CHTE"));calls++;}
+static void apple_smc_write_u8(void *smc,const char *key,uint8_t value){(void)smc;(void)key;assert(value==0);calls++;}
+static void policy(struct device *dev, struct macsmc_power *power){void *smc=0;
+''' + guarded + r'''
+}
+int main(void) {
+ bool t6050=true;struct device parent={.of_node=&t6050},dev={.parent=&parent};
+ struct macsmc_power p={true,true,true};policy(&dev,&p);assert(calls==0);
+ t6050=false;policy(&dev,&p);assert(calls==4);
+ calls=0;p.has_chte=false;policy(&dev,&p);assert(calls==4);
+ calls=0;p.has_ch0c=false;p.has_ch0i=false;policy(&dev,&p);assert(calls==2);
+}
+'''
+with tempfile.TemporaryDirectory(prefix='smc-charge-') as directory:
+ d=Path(directory);(d/'test.c').write_text(program)
+ subprocess.run(['cc','-std=gnu11','-Wall','-Wextra','-Werror','-fsanitize=address,undefined',str(d/'test.c'),'-o',str(d/'test')],check=True)
+ subprocess.run([str(d/'test')],check=True)
+print('T6050 probe preserves charge policy; older-platform reset behavior unchanged')