Commit c2138b25 authored by Hans de Goede's avatar Hans de Goede
Browse files

platform/x86: x86-android-tablets: Add support for instantiating serdevs 



Add support for instantiating serdevs, this is necessary on some boards
where the serdev info in the DSDT has issues.

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211229231431.437982-8-hdegoede@redhat.com
parent 5eba0141

drivers/platform/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -1006,7 +1006,7 @@ config TOUCHSCREEN_DMI 


config X86_ANDROID_TABLETS

	tristate "X86 Android tablet support"

	depends on I2C && ACPI && GPIOLIB

	depends on I2C && SERIAL_DEV_BUS && ACPI && GPIOLIB

	help

	  X86 tablets which ship with Android as (part of) the factory image

	  typically have various problems with their DSDTs. The factory kernels

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

+101 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/module.h>

#include <linux/mod_devicetable.h>

#include <linux/platform_device.h>

#include <linux/serdev.h>

#include <linux/string.h>

/* For gpio_get_desc() which is EXPORT_SYMBOL_GPL() */

#include "../../gpio/gpiolib.h"
@@ -127,11 +128,26 @@ struct x86_i2c_client_info { 
	struct x86_acpi_irq_data irq_data;

};



struct x86_serdev_info {

	const char *ctrl_hid;

	const char *ctrl_uid;

	const char *ctrl_devname;

	/*

	 * ATM the serdev core only supports of or ACPI matching; and sofar all

	 * Android x86 tablets DSDTs have usable serdev nodes, but sometimes

	 * under the wrong controller. So we just tie the existing serdev ACPI

	 * node to the right controller.

	 */

	const char *serdev_hid;

};



struct x86_dev_info {

	const struct x86_i2c_client_info *i2c_client_info;

	const struct platform_device_info *pdev_info;

	const struct x86_serdev_info *serdev_info;

	int i2c_client_count;

	int pdev_count;

	int serdev_count;

};



/*
@@ -273,8 +289,10 @@ MODULE_DEVICE_TABLE(dmi, x86_android_tablet_ids); 


static int i2c_client_count;

static int pdev_count;

static int serdev_count;

static struct i2c_client **i2c_clients;

static struct platform_device **pdevs;

static struct serdev_device **serdevs;



static __init int x86_instantiate_i2c_client(const struct x86_dev_info *dev_info,

					     int idx)
@@ -310,10 +328,78 @@ static __init int x86_instantiate_i2c_client(const struct x86_dev_info *dev_info 
	return 0;

}



static __init int x86_instantiate_serdev(const struct x86_serdev_info *info, int idx)

{

	struct acpi_device *ctrl_adev, *serdev_adev;

	struct serdev_device *serdev;

	struct device *ctrl_dev;

	int ret = -ENODEV;



	ctrl_adev = acpi_dev_get_first_match_dev(info->ctrl_hid, info->ctrl_uid, -1);

	if (!ctrl_adev) {

		pr_err("error could not get %s/%s ctrl adev\n",

		       info->ctrl_hid, info->ctrl_uid);

		return -ENODEV;

	}



	serdev_adev = acpi_dev_get_first_match_dev(info->serdev_hid, NULL, -1);

	if (!serdev_adev) {

		pr_err("error could not get %s serdev adev\n", info->serdev_hid);

		goto put_ctrl_adev;

	}



	/* get_first_physical_node() returns a weak ref, no need to put() it */

	ctrl_dev = acpi_get_first_physical_node(ctrl_adev);

	if (!ctrl_dev)	{

		pr_err("error could not get %s/%s ctrl physical dev\n",

		       info->ctrl_hid, info->ctrl_uid);

		goto put_serdev_adev;

	}



	/* ctrl_dev now points to the controller's parent, get the controller */

	ctrl_dev = device_find_child_by_name(ctrl_dev, info->ctrl_devname);

	if (!ctrl_dev) {

		pr_err("error could not get %s/%s %s ctrl dev\n",

		       info->ctrl_hid, info->ctrl_uid, info->ctrl_devname);

		goto put_serdev_adev;

	}



	serdev = serdev_device_alloc(to_serdev_controller(ctrl_dev));

	if (!serdev) {

		ret = -ENOMEM;

		goto put_serdev_adev;

	}



	ACPI_COMPANION_SET(&serdev->dev, serdev_adev);

	acpi_device_set_enumerated(serdev_adev);



	ret = serdev_device_add(serdev);

	if (ret) {

		dev_err(&serdev->dev, "error %d adding serdev\n", ret);

		serdev_device_put(serdev);

		goto put_serdev_adev;

	}



	serdevs[idx] = serdev;



put_serdev_adev:

	acpi_dev_put(serdev_adev);

put_ctrl_adev:

	acpi_dev_put(ctrl_adev);

	return ret;

}



static void x86_android_tablet_cleanup(void)

{

	int i;



	for (i = 0; i < serdev_count; i++) {

		if (serdevs[i])

			serdev_device_remove(serdevs[i]);

	}



	kfree(serdevs);



	for (i = 0; i < pdev_count; i++)

		platform_device_unregister(pdevs[i]);
@@ -365,6 +451,21 @@ static __init int x86_android_tablet_init(void) 
		}

	}



	serdevs = kcalloc(dev_info->serdev_count, sizeof(*serdevs), GFP_KERNEL);

	if (!serdevs) {

		x86_android_tablet_cleanup();

		return -ENOMEM;

	}



	serdev_count = dev_info->serdev_count;

	for (i = 0; i < serdev_count; i++) {

		ret = x86_instantiate_serdev(&dev_info->serdev_info[i], i);

		if (ret < 0) {

			x86_android_tablet_cleanup();

			return ret;

		}

	}



	return 0;

}