platform/x86: x86-android-tablets: Add support for SPI device instantiation

Some x86 Android tablets have SPI devices which are not properly described
in their DSDT. Add support for instantiating SPI devices.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20231104205828.63139-2-hdegoede@redhat.com

drivers/platform/x86/x86-android-tablets/core.c

@@ -141,9 +141,11 @@ int x86_acpi_irq_helper_get(const struct x86_acpi_irq_data *data)
 }
 
 static int i2c_client_count;
+static int spi_dev_count;
 static int pdev_count;
 static int serdev_count;
 static struct i2c_client **i2c_clients;
+static struct spi_device **spi_devs;
 static struct platform_device **pdevs;
 static struct serdev_device **serdevs;
 static struct gpio_keys_button *buttons;
@@ -185,6 +187,46 @@ static __init int x86_instantiate_i2c_client(const struct x86_dev_info *dev_info
 	return 0;
 }
 
+static __init int x86_instantiate_spi_dev(const struct x86_dev_info *dev_info, int idx)
+{
+	const struct x86_spi_dev_info *spi_dev_info = &dev_info->spi_dev_info[idx];
+	struct spi_board_info board_info = spi_dev_info->board_info;
+	struct spi_controller *controller;
+	struct acpi_device *adev;
+	acpi_handle handle;
+	acpi_status status;
+
+	board_info.irq = x86_acpi_irq_helper_get(&spi_dev_info->irq_data);
+	if (board_info.irq < 0)
+		return board_info.irq;
+
+	status = acpi_get_handle(NULL, spi_dev_info->ctrl_path, &handle);
+	if (ACPI_FAILURE(status)) {
+		pr_err("Error could not get %s handle\n", spi_dev_info->ctrl_path);
+		return -ENODEV;
+	}
+
+	adev = acpi_fetch_acpi_dev(handle);
+	if (!adev) {
+		pr_err("Error could not get adev for %s\n", spi_dev_info->ctrl_path);
+		return -ENODEV;
+	}
+
+	controller = acpi_spi_find_controller_by_adev(adev);
+	if (!controller) {
+		pr_err("Error could not get SPI controller for %s\n", spi_dev_info->ctrl_path);
+		return -ENODEV;
+	}
+
+	spi_devs[idx] = spi_new_device(controller, &board_info);
+	put_device(&controller->dev);
+	if (IS_ERR(spi_devs[idx]))
+		return dev_err_probe(&controller->dev, PTR_ERR(spi_devs[idx]),
+				     "creating SPI-device %d\n", idx);
+
+	return 0;
+}
+
 static __init int x86_instantiate_serdev(const struct x86_serdev_info *info, int idx)
 {
 	struct acpi_device *ctrl_adev, *serdev_adev;
@@ -263,6 +305,11 @@ static void x86_android_tablet_remove(struct platform_device *pdev)
 	kfree(pdevs);
 	kfree(buttons);
 
+	for (i = 0; i < spi_dev_count; i++)
+		spi_unregister_device(spi_devs[i]);
+
+	kfree(spi_devs);
+
 	for (i = 0; i < i2c_client_count; i++)
 		i2c_unregister_device(i2c_clients[i]);
 
@@ -333,6 +380,21 @@ static __init int x86_android_tablet_probe(struct platform_device *pdev)
 		}
 	}
 
+	spi_devs = kcalloc(dev_info->spi_dev_count, sizeof(*spi_devs), GFP_KERNEL);
+	if (!spi_devs) {
+		x86_android_tablet_remove(pdev);
+		return -ENOMEM;
+	}
+
+	spi_dev_count = dev_info->spi_dev_count;
+	for (i = 0; i < spi_dev_count; i++) {
+		ret = x86_instantiate_spi_dev(dev_info, i);
+		if (ret < 0) {
+			x86_android_tablet_remove(pdev);
+			return ret;
+		}
+	}
+
 	/* + 1 to make space for (optional) gpio_keys_button pdev */
 	pdevs = kcalloc(dev_info->pdev_count + 1, sizeof(*pdevs), GFP_KERNEL);
 	if (!pdevs) {

drivers/platform/x86/x86-android-tablets/x86-android-tablets.h

@@ -14,6 +14,7 @@
 #include <linux/gpio_keys.h>
 #include <linux/i2c.h>
 #include <linux/irqdomain_defs.h>
+#include <linux/spi/spi.h>
 
 struct gpio_desc;
 struct gpiod_lookup_table;
@@ -48,6 +49,12 @@ struct x86_i2c_client_info {
 	struct x86_acpi_irq_data irq_data;
 };
 
+struct x86_spi_dev_info {
+	struct spi_board_info board_info;
+	char *ctrl_path;
+	struct x86_acpi_irq_data irq_data;
+};
+
 struct x86_serdev_info {
 	const char *ctrl_hid;
 	const char *ctrl_uid;
@@ -72,10 +79,12 @@ struct x86_dev_info {
 	const struct software_node *bat_swnode;
 	struct gpiod_lookup_table * const *gpiod_lookup_tables;
 	const struct x86_i2c_client_info *i2c_client_info;
+	const struct x86_spi_dev_info *spi_dev_info;
 	const struct platform_device_info *pdev_info;
 	const struct x86_serdev_info *serdev_info;
 	const struct x86_gpio_button *gpio_button;
 	int i2c_client_count;
+	int spi_dev_count;
 	int pdev_count;
 	int serdev_count;
 	int gpio_button_count;