linux-t2-patches/3003-applesmc-switch-to-acpi_device-from-platform.patch

From ee3d4bf4a01bc94553bde2ae3e806a63a13faa12 Mon Sep 17 00:00:00 2001
From: Paul Pawlowski <paul@mrarm.io>
Date: Sun, 17 Nov 2019 23:12:08 +0100
Subject: [PATCH 3/6] applesmc: switch to acpi_device (from platform)

This change makes the change from platform_device
to acpi_device. The rationale for this change is
that on T2 Macs, an additional FixedMemory32
region is needed for device operation, and it can
be easily resolved via ACPI tables (this will be
done in another commit).

Additionally, on older Macs, the OS X driver also
looks for the specified ACPI device to resolve
its memory regions, and therefore this change
should not result in any incompatibilities.

Signed-off-by: Aun-Ali Zaidi <admin@kodeit.net>
---
 drivers/hwmon/applesmc.c | 125 ++++++++++++++++++++++++++-------------
 1 file changed, 85 insertions(+), 40 deletions(-)

diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c
index 39ed0bb21365..bdaaf696f7b6 100644
--- a/drivers/hwmon/applesmc.c
+++ b/drivers/hwmon/applesmc.c
@@ -19,7 +19,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/delay.h>
-#include <linux/platform_device.h>
+#include <linux/acpi.h>
 #include <linux/input.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
@@ -35,7 +35,6 @@
 #include <linux/err.h>
 #include <linux/bits.h>
 
-#define APPLESMC_PORT_BASE	0x300
 /* data port used by Apple SMC */
 #define APPLESMC_DATA_PORT	0
 /* command/status port used by Apple SMC */
@@ -138,9 +137,10 @@ struct applesmc_registers {
 };
 
 struct applesmc_device {
-	struct platform_device *dev;
+	struct acpi_device *dev;
 	struct applesmc_registers reg;
 
+	bool port_base_set;
 	u16 port_base;
 
 	s16 rest_x;
@@ -692,9 +692,13 @@ static int applesmc_init_smcreg(struct applesmc_device *smc)
 }
 
 /* Device model stuff */
+
+static int applesmc_init_resources(struct applesmc_device *smc);
+static void applesmc_free_resources(struct applesmc_device *smc);
 static int applesmc_create_modules(struct applesmc_device *smc);
 static void applesmc_destroy_modules(struct applesmc_device *smc);
-static int applesmc_probe(struct platform_device *dev)
+
+static int applesmc_add(struct acpi_device *dev)
 {
 	struct applesmc_device *smc;
 	int ret;
@@ -705,12 +709,16 @@ static int applesmc_probe(struct platform_device *dev)
 	smc->dev = dev;
 	mutex_init(&smc->reg.mutex);
 
-	platform_set_drvdata(dev, smc);
+	dev_set_drvdata(&dev->dev, smc);
 
-	ret = applesmc_init_smcreg(smc);
+	ret = applesmc_init_resources(smc);
 	if (ret)
 		goto out_mem;
 
+	ret = applesmc_init_smcreg(smc);
+	if (ret)
+		goto out_res;
+
 	applesmc_device_init(smc);
 
 	ret = applesmc_create_modules(smc);
@@ -721,20 +729,23 @@ static int applesmc_probe(struct platform_device *dev)
 
 out_reg:
 	applesmc_destroy_smcreg(smc);
+out_res:
+	applesmc_free_resources(smc);
 out_mem:
-	platform_set_drvdata(dev, NULL);
+	dev_set_drvdata(&dev->dev, NULL);
 	mutex_destroy(&smc->reg.mutex);
 	kfree(smc);
 
 	return ret;
 }
 
-static int applesmc_remove(struct platform_device *dev)
+static int applesmc_remove(struct acpi_device *dev)
 {
-	struct applesmc_device *smc = platform_get_drvdata(dev);
+	struct applesmc_device *smc = dev_get_drvdata(&dev->dev);
 
 	applesmc_destroy_modules(smc);
 	applesmc_destroy_smcreg(smc);
+	applesmc_free_resources(smc);
 
 	mutex_destroy(&smc->reg.mutex);
 	kfree(smc);
@@ -742,6 +753,52 @@ static int applesmc_remove(struct platform_device *dev)
 	return 0;
 }
 
+static acpi_status applesmc_walk_resources(struct acpi_resource *res,
+	void *data)
+{
+	struct applesmc_device *smc = data;
+
+	switch (res->type) {
+	case ACPI_RESOURCE_TYPE_IO:
+		if (!smc->port_base_set) {
+			if (res->data.io.address_length < APPLESMC_NR_PORTS)
+				return AE_ERROR;
+			smc->port_base = res->data.io.minimum;
+			smc->port_base_set = true;
+		}
+		return AE_OK;
+
+	case ACPI_RESOURCE_TYPE_END_TAG:
+		if (smc->port_base_set)
+			return AE_OK;
+		else
+			return AE_NOT_FOUND;
+
+	default:
+		return AE_OK;
+	}
+}
+
+static int applesmc_init_resources(struct applesmc_device *smc)
+{
+	int ret;
+
+	ret = acpi_walk_resources(smc->dev->handle, METHOD_NAME__CRS,
+			applesmc_walk_resources, smc);
+	if (ACPI_FAILURE(ret))
+		return -ENXIO;
+
+	if (!request_region(smc->port_base, APPLESMC_NR_PORTS, "applesmc"))
+		return -ENXIO;
+
+	return 0;
+}
+
+static void applesmc_free_resources(struct applesmc_device *smc)
+{
+	release_region(smc->port_base, APPLESMC_NR_PORTS);
+}
+
 /* Synchronize device with memorized backlight state */
 static int applesmc_pm_resume(struct device *dev)
 {
@@ -763,18 +820,28 @@ static int applesmc_pm_restore(struct device *dev)
 	return applesmc_pm_resume(dev);
 }
 
+static const struct acpi_device_id applesmc_ids[] = {
+	{"APP0001", 0},
+	{"", 0},
+};
+
 static const struct dev_pm_ops applesmc_pm_ops = {
 	.resume = applesmc_pm_resume,
 	.restore = applesmc_pm_restore,
 };
 
-static struct platform_driver applesmc_driver = {
-	.probe = applesmc_probe,
-	.remove = applesmc_remove,
-	.driver	= {
-		.name = "applesmc",
-		.pm = &applesmc_pm_ops,
+static struct acpi_driver applesmc_driver = {
+	.name = "applesmc",
+	.class = "applesmc",
+	.ids = applesmc_ids,
+	.ops = {
+		.add = applesmc_add,
+		.remove = applesmc_remove
 	},
+	.drv = {
+		.pm = &applesmc_pm_ops
+	},
+	.owner = THIS_MODULE
 };
 
 /*
@@ -1262,7 +1329,6 @@ static int applesmc_create_nodes(struct applesmc_device *smc,
 static int applesmc_create_accelerometer(struct applesmc_device *smc)
 {
 	int ret;
-
 	if (!smc->reg.has_accelerometer)
 		return 0;
 
@@ -1463,8 +1529,6 @@ static void applesmc_destroy_modules(struct applesmc_device *smc)
 	applesmc_destroy_nodes(smc, info_group);
 }
 
-static struct platform_device *pdev;
-
 static int __init applesmc_init(void)
 {
 	int ret;
@@ -1475,29 +1539,12 @@ static int __init applesmc_init(void)
 		goto out;
 	}
 
-	if (!request_region(APPLESMC_PORT_BASE, APPLESMC_NR_PORTS,
-								"applesmc")) {
-		ret = -ENXIO;
-		goto out;
-	}
-
-	ret = platform_driver_register(&applesmc_driver);
+	ret = acpi_bus_register_driver(&applesmc_driver);
 	if (ret)
-		goto out_region;
-
-	pdev = platform_device_register_simple("applesmc", APPLESMC_DATA_PORT,
-					       NULL, 0);
-	if (IS_ERR(pdev)) {
-		ret = PTR_ERR(pdev);
-		goto out_driver;
-	}
+		goto out;
 
 	return 0;
 
-out_driver:
-	platform_driver_unregister(&applesmc_driver);
-out_region:
-	release_region(APPLESMC_PORT_BASE, APPLESMC_NR_PORTS);
 out:
 	pr_warn("driver init failed (ret=%d)!\n", ret);
 	return ret;
@@ -1505,9 +1552,7 @@ static int __init applesmc_init(void)
 
 static void __exit applesmc_exit(void)
 {
-	platform_device_unregister(pdev);
-	platform_driver_unregister(&applesmc_driver);
-	release_region(APPLESMC_PORT_BASE, APPLESMC_NR_PORTS);
+	acpi_bus_unregister_driver(&applesmc_driver);
 }
 
 module_init(applesmc_init);
-- 
2.30.0