drivers/platform/x86/i2c-multi-instantiate.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * I2C multi-instantiate driver, pseudo driver to instantiate multiple
   4  * i2c-clients from a single fwnode.
   5  *
   6  * Copyright 2018 Hans de Goede <hdegoede@redhat.com>
   7  */
   8
   9 #include <linux/acpi.h>
  10 #include <linux/i2c.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15
  16 struct i2c_inst_data {
  17         const char *type;
  18         int gpio_irq_idx;
  19 };
  20
  21 struct i2c_multi_inst_data {
  22         int num_clients;
  23         struct i2c_client *clients[0];
  24 };
  25
  26 static int i2c_multi_inst_probe(struct platform_device *pdev)
  27 {
  28         struct i2c_multi_inst_data *multi;
  29         const struct acpi_device_id *match;
  30         const struct i2c_inst_data *inst_data;
  31         struct i2c_board_info board_info = {};
  32         struct device *dev = &pdev->dev;
  33         struct acpi_device *adev;
  34         char name[32];
  35         int i, ret;
  36
  37         match = acpi_match_device(dev->driver->acpi_match_table, dev);
  38         if (!match) {
  39                 dev_err(dev, "Error ACPI match data is missing\n");
  40                 return -ENODEV;
  41         }
  42         inst_data = (const struct i2c_inst_data *)match->driver_data;
  43
  44         adev = ACPI_COMPANION(dev);
  45
  46         /* Count number of clients to instantiate */
  47         for (i = 0; inst_data[i].type; i++) {}
  48
  49         multi = devm_kmalloc(dev,
  50                         offsetof(struct i2c_multi_inst_data, clients[i]),
  51                         GFP_KERNEL);
  52         if (!multi)
  53                 return -ENOMEM;
  54
  55         multi->num_clients = i;
  56
  57         for (i = 0; i < multi->num_clients; i++) {
  58                 memset(&board_info, 0, sizeof(board_info));
  59                 strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
  60                 snprintf(name, sizeof(name), "%s-%s", match->id,
  61                          inst_data[i].type);
  62                 board_info.dev_name = name;
  63                 board_info.irq = 0;
  64                 if (inst_data[i].gpio_irq_idx != -1) {
  65                         ret = acpi_dev_gpio_irq_get(adev,
  66                                                     inst_data[i].gpio_irq_idx);
  67                         if (ret < 0) {
  68                                 dev_err(dev, "Error requesting irq at index %d: %d\n",
  69                                         inst_data[i].gpio_irq_idx, ret);
  70                                 goto error;
  71                         }
  72                         board_info.irq = ret;
  73                 }
  74                 multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
  75                 if (!multi->clients[i]) {
  76                         dev_err(dev, "Error creating i2c-client, idx %d\n", i);
  77                         ret = -ENODEV;
  78                         goto error;
  79                 }
  80         }
  81
  82         platform_set_drvdata(pdev, multi);
  83         return 0;
  84
  85 error:
  86         while (--i >= 0)
  87                 i2c_unregister_device(multi->clients[i]);
  88
  89         return ret;
  90 }
  91
  92 static int i2c_multi_inst_remove(struct platform_device *pdev)
  93 {
  94         struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
  95         int i;
  96
  97         for (i = 0; i < multi->num_clients; i++)
  98                 i2c_unregister_device(multi->clients[i]);
  99
 100         return 0;
 101 }
 102
 103 static const struct i2c_inst_data bsg1160_data[]  = {
 104         { "bmc150_accel", 0 },
 105         { "bmc150_magn", -1 },
 106         { "bmg160", -1 },
 107         {}
 108 };
 109
 110 /*
 111  * Note new device-ids must also be added to i2c_multi_instantiate_ids in
 112  * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
 113  */
 114 static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
 115         { "BSG1160", (unsigned long)bsg1160_data },
 116         { }
 117 };
 118 MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
 119
 120 static struct platform_driver i2c_multi_inst_driver = {
 121         .driver = {
 122                 .name = "I2C multi instantiate pseudo device driver",
 123                 .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
 124         },
 125         .probe = i2c_multi_inst_probe,
 126         .remove = i2c_multi_inst_remove,
 127 };
 128 module_platform_driver(i2c_multi_inst_driver);
 129
 130 MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
 131 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 132 MODULE_LICENSE("GPL");