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/bits.h>
  11 #include <linux/i2c.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/types.h>
  17
  18 #define IRQ_RESOURCE_TYPE       GENMASK(1, 0)
  19 #define IRQ_RESOURCE_NONE       0
  20 #define IRQ_RESOURCE_GPIO       1
  21 #define IRQ_RESOURCE_APIC       2
  22
  23 struct i2c_inst_data {
  24         const char *type;
  25         unsigned int flags;
  26         int irq_idx;
  27 };
  28
  29 struct i2c_multi_inst_data {
  30         int num_clients;
  31         struct i2c_client *clients[0];
  32 };
  33
  34 static int i2c_multi_inst_count(struct acpi_resource *ares, void *data)
  35 {
  36         struct acpi_resource_i2c_serialbus *sb;
  37         int *count = data;
  38
  39         if (i2c_acpi_get_i2c_resource(ares, &sb))
  40                 *count = *count + 1;
  41
  42         return 1;
  43 }
  44
  45 static int i2c_multi_inst_count_resources(struct acpi_device *adev)
  46 {
  47         LIST_HEAD(r);
  48         int count = 0;
  49         int ret;
  50
  51         ret = acpi_dev_get_resources(adev, &r, i2c_multi_inst_count, &count);
  52         if (ret < 0)
  53                 return ret;
  54
  55         acpi_dev_free_resource_list(&r);
  56         return count;
  57 }
  58
  59 static int i2c_multi_inst_probe(struct platform_device *pdev)
  60 {
  61         struct i2c_multi_inst_data *multi;
  62         const struct acpi_device_id *match;
  63         const struct i2c_inst_data *inst_data;
  64         struct i2c_board_info board_info = {};
  65         struct device *dev = &pdev->dev;
  66         struct acpi_device *adev;
  67         char name[32];
  68         int i, ret;
  69
  70         match = acpi_match_device(dev->driver->acpi_match_table, dev);
  71         if (!match) {
  72                 dev_err(dev, "Error ACPI match data is missing\n");
  73                 return -ENODEV;
  74         }
  75         inst_data = (const struct i2c_inst_data *)match->driver_data;
  76
  77         adev = ACPI_COMPANION(dev);
  78
  79         /* Count number of clients to instantiate */
  80         ret = i2c_multi_inst_count_resources(adev);
  81         if (ret < 0)
  82                 return ret;
  83
  84         multi = devm_kmalloc(dev,
  85                         offsetof(struct i2c_multi_inst_data, clients[ret]),
  86                         GFP_KERNEL);
  87         if (!multi)
  88                 return -ENOMEM;
  89
  90         multi->num_clients = ret;
  91
  92         for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
  93                 memset(&board_info, 0, sizeof(board_info));
  94                 strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
  95                 snprintf(name, sizeof(name), "%s-%s.%d", match->id,
  96                          inst_data[i].type, i);
  97                 board_info.dev_name = name;
  98                 switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
  99                 case IRQ_RESOURCE_GPIO:
 100                         ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
 101                         if (ret < 0) {
 102                                 dev_err(dev, "Error requesting irq at index %d: %d\n",
 103                                         inst_data[i].irq_idx, ret);
 104                                 goto error;
 105                         }
 106                         board_info.irq = ret;
 107                         break;
 108                 case IRQ_RESOURCE_APIC:
 109                         ret = platform_get_irq(pdev, inst_data[i].irq_idx);
 110                         if (ret < 0) {
 111                                 dev_dbg(dev, "Error requesting irq at index %d: %d\n",
 112                                         inst_data[i].irq_idx, ret);
 113                         }
 114                         board_info.irq = ret;
 115                         break;
 116                 default:
 117                         board_info.irq = 0;
 118                         break;
 119                 }
 120                 multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
 121                 if (IS_ERR(multi->clients[i])) {
 122                         ret = PTR_ERR(multi->clients[i]);
 123                         if (ret != -EPROBE_DEFER)
 124                                 dev_err(dev, "Error creating i2c-client, idx %d\n", i);
 125                         goto error;
 126                 }
 127         }
 128         if (i < multi->num_clients) {
 129                 dev_err(dev, "Error finding driver, idx %d\n", i);
 130                 ret = -ENODEV;
 131                 goto error;
 132         }
 133
 134         platform_set_drvdata(pdev, multi);
 135         return 0;
 136
 137 error:
 138         while (--i >= 0)
 139                 i2c_unregister_device(multi->clients[i]);
 140
 141         return ret;
 142 }
 143
 144 static int i2c_multi_inst_remove(struct platform_device *pdev)
 145 {
 146         struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
 147         int i;
 148
 149         for (i = 0; i < multi->num_clients; i++)
 150                 i2c_unregister_device(multi->clients[i]);
 151
 152         return 0;
 153 }
 154
 155 static const struct i2c_inst_data bsg1160_data[]  = {
 156         { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
 157         { "bmc150_magn" },
 158         { "bmg160" },
 159         {}
 160 };
 161
 162 static const struct i2c_inst_data bsg2150_data[]  = {
 163         { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
 164         { "bmc150_magn" },
 165         /* The resources describe a 3th client, but it is not really there. */
 166         { "bsg2150_dummy_dev" },
 167         {}
 168 };
 169
 170 static const struct i2c_inst_data int3515_data[]  = {
 171         { "tps6598x", IRQ_RESOURCE_APIC, 0 },
 172         { "tps6598x", IRQ_RESOURCE_APIC, 1 },
 173         { "tps6598x", IRQ_RESOURCE_APIC, 2 },
 174         { "tps6598x", IRQ_RESOURCE_APIC, 3 },
 175         {}
 176 };
 177
 178 /*
 179  * Note new device-ids must also be added to i2c_multi_instantiate_ids in
 180  * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
 181  */
 182 static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
 183         { "BSG1160", (unsigned long)bsg1160_data },
 184         { "BSG2150", (unsigned long)bsg2150_data },
 185         { "INT3515", (unsigned long)int3515_data },
 186         { }
 187 };
 188 MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
 189
 190 static struct platform_driver i2c_multi_inst_driver = {
 191         .driver = {
 192                 .name = "I2C multi instantiate pseudo device driver",
 193                 .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
 194         },
 195         .probe = i2c_multi_inst_probe,
 196         .remove = i2c_multi_inst_remove,
 197 };
 198 module_platform_driver(i2c_multi_inst_driver);
 199
 200 MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
 201 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 202 MODULE_LICENSE("GPL");