--- /dev/null
+ // 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");
gentwo / linux / .git / commitdiff