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