linux/drivers/platform/x86/i2c-multi-instantiate.c
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   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
  23struct i2c_inst_data {
  24        const char *type;
  25        unsigned int flags;
  26        int irq_idx;
  27};
  28
  29struct i2c_multi_inst_data {
  30        int num_clients;
  31        struct i2c_client *clients[0];
  32};
  33
  34static 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
  45static 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
  59static 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
 136error:
 137        while (--i >= 0)
 138                i2c_unregister_device(multi->clients[i]);
 139
 140        return ret;
 141}
 142
 143static 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
 154static const struct i2c_inst_data bsg1160_data[]  = {
 155        { "bmc150_accel", IRQ_RESOURCE_GPIO, 0 },
 156        { "bmc150_magn" },
 157        { "bmg160" },
 158        {}
 159};
 160
 161static 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
 169static 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 */
 181static 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};
 187MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
 188
 189static 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};
 197module_platform_driver(i2c_multi_inst_driver);
 198
 199MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
 200MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
 201MODULE_LICENSE("GPL");
 202