diff options
Diffstat (limited to 'drivers/platform/x86/dell/dell-lis3lv02d.c')
| -rw-r--r-- | drivers/platform/x86/dell/dell-lis3lv02d.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/platform/x86/dell/dell-lis3lv02d.c b/drivers/platform/x86/dell/dell-lis3lv02d.c new file mode 100644 index 000000000000..efe26d667973 --- /dev/null +++ b/drivers/platform/x86/dell/dell-lis3lv02d.c @@ -0,0 +1,256 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * lis3lv02d i2c-client instantiation for ACPI SMO88xx devices without I2C resources. + * + * Copyright (C) 2024 Hans de Goede <hansg@kernel.org> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/device/bus.h> +#include <linux/dmi.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/notifier.h> +#include <linux/platform_device.h> +#include <linux/workqueue.h> +#include "dell-smo8800-ids.h" + +#define LIS3_WHO_AM_I 0x0f + +#define DELL_LIS3LV02D_DMI_ENTRY(product_name, i2c_addr) \ + { \ + .matches = { \ + DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."), \ + DMI_EXACT_MATCH(DMI_PRODUCT_NAME, product_name), \ + }, \ + .driver_data = (void *)(uintptr_t)(i2c_addr), \ + } + +/* + * Accelerometer's I2C address is not specified in DMI nor ACPI, + * so it is needed to define mapping table based on DMI product names. + */ +static const struct dmi_system_id lis3lv02d_devices[] __initconst = { + /* + * Dell platform team told us that these Latitude devices have + * ST microelectronics accelerometer at I2C address 0x29. + */ + DELL_LIS3LV02D_DMI_ENTRY("Latitude E5250", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E5450", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E5550", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E6440", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E6440 ATG", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E6540", 0x29), + /* + * Additional individual entries were added after verification. + */ + DELL_LIS3LV02D_DMI_ENTRY("Latitude 5480", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E6330", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Latitude E6430", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Precision 3540", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Precision M6800", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("Vostro V131", 0x1d), + DELL_LIS3LV02D_DMI_ENTRY("Vostro 5568", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("XPS 15 7590", 0x29), + DELL_LIS3LV02D_DMI_ENTRY("XPS 15 9550", 0x29), + { } +}; + +static u8 i2c_addr; +static struct i2c_client *i2c_dev; +static bool notifier_registered; + +static bool probe_i2c_addr; +module_param(probe_i2c_addr, bool, 0444); +MODULE_PARM_DESC(probe_i2c_addr, "Probe the i801 I2C bus for the accelerometer on models where the address is unknown, this may be dangerous."); + +static int detect_lis3lv02d(struct i2c_adapter *adap, unsigned short addr) +{ + union i2c_smbus_data smbus_data; + int err; + + dev_info(&adap->dev, "Probing for lis3lv02d on address 0x%02x\n", addr); + + err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, LIS3_WHO_AM_I, + I2C_SMBUS_BYTE_DATA, &smbus_data); + if (err < 0) + return 0; /* Not found */ + + /* valid who-am-i values are from drivers/misc/lis3lv02d/lis3lv02d.c */ + switch (smbus_data.byte) { + case 0x32: + case 0x33: + case 0x3a: + case 0x3b: + break; + default: + dev_warn(&adap->dev, "Unknown who-am-i register value 0x%02x\n", + smbus_data.byte); + return 0; /* Not found */ + } + + dev_info(&adap->dev, + "Detected lis3lv02d on address 0x%02x, please report this upstream to platform-driver-x86@vger.kernel.org so that a quirk can be added\n", + addr); + + return 1; /* Found */ +} + +static bool i2c_adapter_is_main_i801(struct i2c_adapter *adap) +{ + /* + * Only match the main I801 adapter and reject secondary adapters + * which names start with "SMBus I801 IDF adapter". + */ + return strstarts(adap->name, "SMBus I801 adapter"); +} + +static int find_i801(struct device *dev, void *data) +{ + struct i2c_adapter *adap, **adap_ret = data; + + adap = i2c_verify_adapter(dev); + if (!adap) + return 0; + + if (!i2c_adapter_is_main_i801(adap)) + return 0; + + *adap_ret = i2c_get_adapter(adap->nr); + return 1; +} + +static void instantiate_i2c_client(struct work_struct *work) +{ + struct i2c_board_info info = { }; + struct i2c_adapter *adap = NULL; + + if (i2c_dev) + return; + + /* + * bus_for_each_dev() and not i2c_for_each_dev() to avoid + * a deadlock when find_i801() calls i2c_get_adapter(). + */ + bus_for_each_dev(&i2c_bus_type, NULL, &adap, find_i801); + if (!adap) + return; + + strscpy(info.type, "lis3lv02d", I2C_NAME_SIZE); + + if (i2c_addr) { + info.addr = i2c_addr; + i2c_dev = i2c_new_client_device(adap, &info); + } else { + /* First try address 0x29 (most used) and then try 0x1d */ + static const unsigned short addr_list[] = { 0x29, 0x1d, I2C_CLIENT_END }; + + i2c_dev = i2c_new_scanned_device(adap, &info, addr_list, detect_lis3lv02d); + } + + if (IS_ERR(i2c_dev)) { + dev_err(&adap->dev, "error %ld registering i2c_client\n", PTR_ERR(i2c_dev)); + i2c_dev = NULL; + } else { + dev_dbg(&adap->dev, "registered lis3lv02d on address 0x%02x\n", info.addr); + } + + i2c_put_adapter(adap); +} +static DECLARE_WORK(i2c_work, instantiate_i2c_client); + +static int i2c_bus_notify(struct notifier_block *nb, unsigned long action, void *data) +{ + struct device *dev = data; + struct i2c_client *client; + struct i2c_adapter *adap; + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + adap = i2c_verify_adapter(dev); + if (!adap) + break; + + if (i2c_adapter_is_main_i801(adap)) + queue_work(system_long_wq, &i2c_work); + break; + case BUS_NOTIFY_REMOVED_DEVICE: + client = i2c_verify_client(dev); + if (!client) + break; + + if (i2c_dev == client) { + dev_dbg(&client->adapter->dev, "lis3lv02d i2c_client removed\n"); + i2c_dev = NULL; + } + break; + default: + break; + } + + return 0; +} +static struct notifier_block i2c_nb = { .notifier_call = i2c_bus_notify }; + +static int __init match_acpi_device_ids(struct device *dev, const void *data) +{ + return acpi_match_device(data, dev) ? 1 : 0; +} + +static int __init dell_lis3lv02d_init(void) +{ + const struct dmi_system_id *lis3lv02d_dmi_id; + struct device *dev; + int err; + + /* + * First check for a matching platform_device. This protects against + * SMO88xx ACPI fwnodes which actually do have an I2C resource, which + * will already have an i2c_client instantiated (not a platform_device). + */ + dev = bus_find_device(&platform_bus_type, NULL, smo8800_ids, match_acpi_device_ids); + if (!dev) { + pr_debug("No SMO88xx platform-device found\n"); + return 0; + } + put_device(dev); + + lis3lv02d_dmi_id = dmi_first_match(lis3lv02d_devices); + if (!lis3lv02d_dmi_id && !probe_i2c_addr) { + pr_warn("accelerometer is present on SMBus but its address is unknown, skipping registration\n"); + pr_info("Pass dell_lis3lv02d.probe_i2c_addr=1 on the kernel command line to probe, this may be dangerous!\n"); + return 0; + } + + if (lis3lv02d_dmi_id) + i2c_addr = (long)lis3lv02d_dmi_id->driver_data; + + /* + * Register i2c-bus notifier + queue initial scan for lis3lv02d + * i2c_client instantiation. + */ + err = bus_register_notifier(&i2c_bus_type, &i2c_nb); + if (err) + return err; + + notifier_registered = true; + + queue_work(system_long_wq, &i2c_work); + return 0; +} +module_init(dell_lis3lv02d_init); + +static void __exit dell_lis3lv02d_module_exit(void) +{ + if (!notifier_registered) + return; + + bus_unregister_notifier(&i2c_bus_type, &i2c_nb); + cancel_work_sync(&i2c_work); + i2c_unregister_device(i2c_dev); +} +module_exit(dell_lis3lv02d_module_exit); + +MODULE_DESCRIPTION("lis3lv02d i2c-client instantiation for ACPI SMO88xx devices"); +MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>"); +MODULE_LICENSE("GPL"); |