Allow using the IIO st_accel driver so that the accelerometer gets presented to userspace as an IIO device like all modern accelerometer drivers do. Note the default is still to use the drivers/misc/lis3lv02d/lis3lv02d.c /dev/freefall + evdev joystick emulation driver, so as to not break existing userspace consumers. /dev/freefall is used by the tools/laptop/freefall/freefall.c tool which is shipped by the kernel as well as by the linux-thinkpad hdapsd daemon. Using the IIO st_accel driver can be enabled by setting the new use_iio_driver module parameter. Link: https://github.com/linux-thinkpad/hdapsd/ Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- Changes in v2: - Keep using drivers/misc/lis3lv02d/lis3lv02d.c be default - Rename the module-parameter to use_iio_driver which can be set to use the IIO st_accel driver instead --- drivers/platform/x86/dell/dell-smo8800.c | 83 ++++++++++++++++++++++-- 1 file changed, 79 insertions(+), 4 deletions(-) diff --git a/drivers/platform/x86/dell/dell-smo8800.c b/drivers/platform/x86/dell/dell-smo8800.c index 3e64ebcf4b21..58bb7275ba5c 100644 --- a/drivers/platform/x86/dell/dell-smo8800.c +++ b/drivers/platform/x86/dell/dell-smo8800.c @@ -10,6 +10,7 @@ */ #define DRIVER_NAME "smo8800" +#define LIS3_WHO_AM_I 0x0f #include <linux/device/bus.h> #include <linux/dmi.h> @@ -24,6 +25,10 @@ #include <linux/platform_device.h> #include <linux/uaccess.h> +static bool use_iio_driver; +module_param(use_iio_driver, bool, 0444); +MODULE_PARM_DESC(use_iio_driver, "Use IIO accelerometer driver instead of /dev/freefall chardev + evdev joystick emulation"); + struct smo8800_device { u32 irq; /* acpi device irq */ atomic_t counter; /* count after last read */ @@ -145,6 +150,65 @@ static int smo8800_find_i801(struct device *dev, void *data) return 1; } +/* + * Set label to let iio-sensor-proxy know these freefall sensors are located in + * the laptop base (not the display) and are not intended for screen rotation. + */ +static const struct property_entry smo8800_accel_props[] = { + PROPERTY_ENTRY_STRING("label", "accel-base"), + {} +}; + +const struct software_node smo8800_accel_node = { + .properties = smo8800_accel_props, +}; + +static int smo8800_detect_accel(struct smo8800_device *smo8800, + struct i2c_adapter *adap, u8 addr, + struct i2c_board_info *info) +{ + union i2c_smbus_data smbus_data; + const char *type; + int err; + + err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, LIS3_WHO_AM_I, + I2C_SMBUS_BYTE_DATA, &smbus_data); + if (err < 0) { + dev_warn(smo8800->dev, "Failed to read who-am-i register: %d\n", err); + return err; + } + + /* + * These who-am-i register mappings to model strings have been + * taken from the old /dev/freefall chardev and joystick driver: + * drivers/misc/lis3lv02d/lis3lv02d.c + */ + switch (smbus_data.byte) { + case 0x32: + type = "lis331dlh"; + break; + case 0x33: + type = "lis2de12"; /* LIS3DC / HP3DC in drivers/misc/lis3lv02d/lis3lv02d.c */ + break; + case 0x3a: + type = "lis3lv02dl_accel"; + break; + case 0x3b: + type = "lis302dl"; + break; + default: + dev_warn(smo8800->dev, "Unknown who-am-i register value 0x%02x\n", + smbus_data.byte); + return -ENODEV; + } + + strscpy(info->type, type, I2C_NAME_SIZE); + info->addr = addr; + info->irq = smo8800->irq; + info->swnode = &smo8800_accel_node; + return 0; +} + /* * Accelerometer's I2C address is not specified in DMI nor ACPI, * so it is needed to define mapping table based on DMI product names. @@ -177,7 +241,7 @@ static void smo8800_instantiate_i2c_client(struct smo8800_device *smo8800) struct i2c_adapter *adap = NULL; const char *dmi_product_name; u8 addr = 0; - int i; + int i, err; bus_for_each_dev(&i2c_bus_type, NULL, &adap, smo8800_find_i801); if (!adap) @@ -198,9 +262,20 @@ static void smo8800_instantiate_i2c_client(struct smo8800_device *smo8800) goto put_adapter; } - info.addr = addr; - info.irq = smo8800->irq; - strscpy(info.type, "lis3lv02d", I2C_NAME_SIZE); + /* Always detect the accel-type, this also checks the accel is actually there */ + err = smo8800_detect_accel(smo8800, adap, addr, &info); + if (err) + goto put_adapter; + + /* + * Unless using the IIO driver is requested, override the detected type + * with "lis3lv02d" so that drivers/misc/lis3lv02d/lis3lv02d.c is used + * and /dev/freefall functionality is provided. + */ + if (!use_iio_driver) { + strscpy(info.type, "lis3lv02d", I2C_NAME_SIZE); + info.swnode = NULL; + } smo8800->i2c_dev = i2c_new_client_device(adap, &info); if (IS_ERR(smo8800->i2c_dev)) { -- 2.43.0
