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, struct_size(multi, clients, ret), GFP_KERNEL);
  85         if (!multi)
  86                 return -ENOMEM;
  87
  88         multi->num_clients = ret;
  89
  90         for (i = 0; i < multi->num_clients && inst_data[i].type; i++) {
  91                 memset(&board_info, 0, sizeof(board_info));
  92                 strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
  93                 snprintf(name, sizeof(name), "%s-%s.%d", dev_name(dev),
  94                          inst_data[i].type, i);
  95                 board_info.dev_name = name;
  96                 switch (inst_data[i].flags & IRQ_RESOURCE_TYPE) {
  97                 case IRQ_RESOURCE_GPIO:
  98                         ret = acpi_dev_gpio_irq_get(adev, inst_data[i].irq_idx);
  99                         if (ret < 0) {
 100                                 dev_err(dev, "Error requesting irq at index %d: %d\n",
 101                                         inst_data[i].irq_idx, ret);
 102                                 goto error;
 103                         }
 104                         board_info.irq = ret;
 105                         break;
 106                 case IRQ_RESOURCE_APIC:
 107                         ret = platform_get_irq(pdev, inst_data[i].irq_idx);
 108                         if (ret < 0) {
 109                                 dev_dbg(dev, "Error requesting irq at index %d: %d\n",
 110                                         inst_data[i].irq_idx, ret);
 111                                 goto error;
 112                         }
 113                         board_info.irq = ret;
 114                         break;
 115                 default:
 116                         board_info.irq = 0;
 117                         break;
 118                 }
 119                 multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
 120                 if (IS_ERR(multi->clients[i])) {
 121                         ret = PTR_ERR(multi->clients[i]);
 122                         if (ret != -EPROBE_DEFER)
 123                                 dev_err(dev, "Error creating i2c-client, idx %d\n", i);
 124                         goto error;
 125                 }
 126         }
 127         if (i < multi->num_clients) {
 128                 dev_err(dev, "Error finding driver, idx %d\n", i);
 129                 ret = -ENODEV;
 130                 goto error;
 131         }
 132
 133         platform_set_drvdata(pdev, multi);
 134         return 0;
 135
 136 error:
 137         while (--i >= 0)
 138                 i2c_unregister_device(multi->clients[i]);
 139
 140         return ret;
 141 }
 142
 143 static int i2c_multi_inst_remove(struct platform_device *pdev)
 144 {
 145         struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
 146         int i;
 147
 148         for (i = 0; i < multi->num_clients; i++)
 149                 i2c_unregister_device(multi->clients[i]);
 150
 151         return 0;
 152 }
 153
 154 static const struct i2c_inst_data bsg1160_data[]  = {
 155         { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
 156         { "bmc150_magn" },
 157         { "bmg160" },
 158         {}
 159 };
 160
 161 static const struct i2c_inst_data bsg2150_data[]  = {
 162         { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
 163         { "bmc150_magn" },
 164         /* The resources describe a 3th client, but it is not really there. */
 165         { "bsg2150_dummy_dev" },
 166         {}
 167 };
 168
 169 static const struct i2c_inst_data int3515_data[]  = {
 170         { "tps6598x", IRQ_RESOURCE_APIC, 0 },
 171         { "tps6598x", IRQ_RESOURCE_APIC, 1 },
 172         { "tps6598x", IRQ_RESOURCE_APIC, 2 },
 173         { "tps6598x", IRQ_RESOURCE_APIC, 3 },
 174         {}
 175 };
 176
 177 /*
 178  * Note new device-ids must also be added to i2c_multi_instantiate_ids in
 179  * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
 180  */
 181 static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
 182         { "BSG1160", (unsigned long)bsg1160_data },
 183         { "BSG2150", (unsigned long)bsg2150_data },
 184         { "INT3515", (unsigned long)int3515_data },
 185         { }
 186 };
 187 MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
 188
 189 static struct platform_driver i2c_multi_inst_driver = {
 190         .driver = {
 191                 .name = "I2C multi instantiate pseudo device driver",
 192                 .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
 193         },
 194         .probe = i2c_multi_inst_probe,
 195         .remove = i2c_multi_inst_remove,
 196 };
 197 module_platform_driver(i2c_multi_inst_driver);
 198
 199 MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
 200 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 201 MODULE_LICENSE("GPL");