root/drivers/iio/accel/bmc150-accel-i2c.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * 3-axis accelerometer driver supporting many I2C Bosch-Sensortec chips
 * Copyright (c) 2014, Intel Corporation.
 */

#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/regmap.h>

#include "bmc150-accel.h"

#ifdef CONFIG_ACPI
static const struct acpi_device_id bmc150_acpi_dual_accel_ids[] = {
        {"BOSC0200"},
        {"DUAL250E"},
        { }
};

/*
 * The DUAL250E ACPI device for 360° hinges type 2-in-1s with 1 accelerometer
 * in the display and 1 in the hinge has an ACPI-method (DSM) to tell the
 * ACPI code about the angle between the 2 halves. This will make the ACPI
 * code enable/disable the keyboard and touchpad. We need to call this to avoid
 * the keyboard being disabled when the 2-in-1 is turned-on or resumed while
 * fully folded into tablet mode (which gets detected with a HALL-sensor).
 * If we don't call this then the keyboard won't work even when the 2-in-1 is
 * changed to be used in laptop mode after the power-on / resume.
 *
 * This DSM takes 2 angles, selected by setting aux0 to 0 or 1, these presumably
 * define the angle between the gravity vector measured by the accelerometer in
 * the display (aux0=0) resp. the base (aux0=1) and some reference vector.
 * The 2 angles get subtracted from each other so the reference vector does
 * not matter and we can simply leave the second angle at 0.
 */

#define BMC150_DSM_GUID                         "7681541e-8827-4239-8d9d-36be7fe12542"
#define DUAL250E_SET_ANGLE_FN_INDEX             3

struct dual250e_set_angle_args {
        u32 aux0;
        u32 ang0;
        u32 rawx;
        u32 rawy;
        u32 rawz;
} __packed;

static bool bmc150_acpi_set_angle_dsm(struct i2c_client *client, u32 aux0, u32 ang0)
{
        struct acpi_device *adev = ACPI_COMPANION(&client->dev);
        struct dual250e_set_angle_args args = {
                .aux0 = aux0,
                .ang0 = ang0,
        };
        union acpi_object args_obj, *obj;
        guid_t guid;

        if (!acpi_dev_hid_uid_match(adev, "DUAL250E", NULL))
                return false;

        guid_parse(BMC150_DSM_GUID, &guid);

        if (!acpi_check_dsm(adev->handle, &guid, 0, BIT(DUAL250E_SET_ANGLE_FN_INDEX)))
                return false;

        /*
         * Note this triggers the following warning:
         * "ACPI Warning: \_SB.PCI0.I2C2.ACC1._DSM: Argument #4 type mismatch -
         *                Found [Buffer], ACPI requires [Package]"
         * This is unavoidable since the _DSM implementation expects a "naked"
         * buffer, so wrapping it in a package will _not_ work.
         */
        args_obj.type = ACPI_TYPE_BUFFER;
        args_obj.buffer.length = sizeof(args);
        args_obj.buffer.pointer = (u8 *)&args;

        obj = acpi_evaluate_dsm(adev->handle, &guid, 0, DUAL250E_SET_ANGLE_FN_INDEX, &args_obj);
        if (!obj) {
                dev_err(&client->dev, "Failed to call DSM to enable keyboard and touchpad\n");
                return false;
        }

        ACPI_FREE(obj);
        return true;
}

static bool bmc150_acpi_enable_keyboard(struct i2c_client *client)
{
        /*
         * The EC must see a change for it to re-enable the kbd, so first
         * set the angle to 270° (tent/stand mode) and then change it to
         * 90° (laptop mode).
         */
        if (!bmc150_acpi_set_angle_dsm(client, 0, 270))
                return false;

        /* The EC needs some time to notice the angle being changed */
        msleep(100);

        return bmc150_acpi_set_angle_dsm(client, 0, 90);
}

static void bmc150_acpi_resume_work(struct work_struct *work)
{
        struct bmc150_accel_data *data =
                container_of(work, struct bmc150_accel_data, resume_work.work);

        bmc150_acpi_enable_keyboard(data->second_device);
}

static void bmc150_acpi_resume_handler(struct device *dev)
{
        struct bmc150_accel_data *data = iio_priv(dev_get_drvdata(dev));

        /*
         * Delay the bmc150_acpi_enable_keyboard() call till after the system
         * resume has completed, otherwise it will not work.
         */
        schedule_delayed_work(&data->resume_work, msecs_to_jiffies(1000));
}

/*
 * Some acpi_devices describe 2 accelerometers in a single ACPI device,
 * try instantiating a second i2c_client for an I2cSerialBusV2 ACPI resource
 * with index 1.
 */
static void bmc150_acpi_dual_accel_probe(struct i2c_client *client)
{
        struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client));
        struct acpi_device *adev = ACPI_COMPANION(&client->dev);
        char dev_name[16];
        struct i2c_board_info board_info = {
                .type = "bmc150_accel",
                .dev_name = dev_name,
                .fwnode = client->dev.fwnode,
        };

        if (acpi_match_device_ids(adev, bmc150_acpi_dual_accel_ids))
                return;

        /*
         * The 2nd accel sits in the base of 2-in-1s. The suffix is static, as
         * there should never be more then 1 ACPI node with 2 accelerometers.
         */
        snprintf(dev_name, sizeof(dev_name), "%s:base", acpi_device_hid(adev));

        board_info.irq = acpi_dev_gpio_irq_get(adev, 1);

        data->second_device = i2c_acpi_new_device(&client->dev, 1, &board_info);

        if (!IS_ERR(data->second_device) && bmc150_acpi_enable_keyboard(data->second_device)) {
                INIT_DELAYED_WORK(&data->resume_work, bmc150_acpi_resume_work);
                data->resume_callback = bmc150_acpi_resume_handler;
        }
}

static void bmc150_acpi_dual_accel_remove(struct i2c_client *client)
{
        struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client));

        if (data->resume_callback)
                cancel_delayed_work_sync(&data->resume_work);

        i2c_unregister_device(data->second_device);
}
#else
static void bmc150_acpi_dual_accel_probe(struct i2c_client *client) {}
static void bmc150_acpi_dual_accel_remove(struct i2c_client *client) {}
#endif

static int bmc150_accel_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        struct regmap *regmap;
        const char *name = NULL;
        enum bmc150_type type = BOSCH_UNKNOWN;
        bool block_supported =
                i2c_check_functionality(client->adapter, I2C_FUNC_I2C) ||
                i2c_check_functionality(client->adapter,
                                        I2C_FUNC_SMBUS_READ_I2C_BLOCK);
        int ret;

        regmap = devm_regmap_init_i2c(client, &bmc150_regmap_conf);
        if (IS_ERR(regmap)) {
                dev_err(&client->dev, "Failed to initialize i2c regmap\n");
                return PTR_ERR(regmap);
        }

        if (id) {
                name = id->name;
                type = id->driver_data;
        }

        ret = bmc150_accel_core_probe(&client->dev, regmap, client->irq,
                                      type, name, block_supported);
        if (ret)
                return ret;

        /*
         * The !id check avoids recursion when probe() gets called
         * for the second client.
         */
        if (!id && has_acpi_companion(&client->dev))
                bmc150_acpi_dual_accel_probe(client);

        return 0;
}

static void bmc150_accel_remove(struct i2c_client *client)
{
        bmc150_acpi_dual_accel_remove(client);

        bmc150_accel_core_remove(&client->dev);
}

static const struct acpi_device_id bmc150_accel_acpi_match[] = {
        {"BMA0255"},
        {"BMA0280"},
        {"BMA222"},
        {"BMA222E"},
        {"BMA250E"},
        {"BMC150A"},
        {"BMI055A"},
        /*
         * The "BOSC0200" identifier used here is not unique to devices using
         * bmc150. The same "BOSC0200" identifier is found in the ACPI tables
         * of the ASUS ROG ALLY and Ayaneo AIR Plus which both use a Bosch
         * BMI323 chip. This creates a conflict with duplicate ACPI identifiers
         * which multiple drivers want to use. Fortunately, when the bmc150
         * driver starts to load on the ASUS ROG ALLY, the chip ID check
         * portion fails (correctly) because the chip IDs received (via i2c)
         * are unique between bmc150 and bmi323 and a dmesg output similar to
         * this: "bmc150_accel_i2c i2c-BOSC0200:00: Invalid chip 0" can be
         * seen. This allows the bmi323 driver to take over for ASUS ROG ALLY,
         * and other devices using the bmi323 chip.
         */
        {"BOSC0200"},
        {"BSBA0150"},
        {"DUAL250E"},
        { }
};
MODULE_DEVICE_TABLE(acpi, bmc150_accel_acpi_match);

static const struct i2c_device_id bmc150_accel_id[] = {
        {"bma222"},
        {"bma222e"},
        {"bma250e"},
        {"bma253"},
        {"bma254"},
        {"bma255"},
        {"bma280"},
        {"bmc150_accel"},
        {"bmc156_accel", BOSCH_BMC156},
        {"bmi055_accel"},
        { }
};

MODULE_DEVICE_TABLE(i2c, bmc150_accel_id);

static const struct of_device_id bmc150_accel_of_match[] = {
        { .compatible = "bosch,bma222" },
        { .compatible = "bosch,bma222e" },
        { .compatible = "bosch,bma250e" },
        { .compatible = "bosch,bma253" },
        { .compatible = "bosch,bma254" },
        { .compatible = "bosch,bma255" },
        { .compatible = "bosch,bma280" },
        { .compatible = "bosch,bmc150_accel" },
        { .compatible = "bosch,bmc156_accel" },
        { .compatible = "bosch,bmi055_accel" },
        { }
};
MODULE_DEVICE_TABLE(of, bmc150_accel_of_match);

static struct i2c_driver bmc150_accel_driver = {
        .driver = {
                .name   = "bmc150_accel_i2c",
                .of_match_table = bmc150_accel_of_match,
                .acpi_match_table = bmc150_accel_acpi_match,
                .pm     = &bmc150_accel_pm_ops,
        },
        .probe          = bmc150_accel_probe,
        .remove         = bmc150_accel_remove,
        .id_table       = bmc150_accel_id,
};
module_i2c_driver(bmc150_accel_driver);

MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("BMC150 I2C accelerometer driver");
MODULE_IMPORT_NS("IIO_BMC150");