LXR uboot/drivers/i2c/i2c-emul-uclass.c

   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (c) 2014 Google, Inc
   4 */
   5
   6#define LOG_CATEGORY UCLASS_I2C_EMUL
   7
   8#include <common.h>
   9#include <dm.h>
  10#include <i2c.h>
  11#include <log.h>
  12#include <asm/i2c.h>
  13#include <dm/device-internal.h>
  14#include <dm/uclass-internal.h>
  15
  16/*
  17 * i2c emulation works using an 'emul' node at the bus level. Each device in
  18 * that node is in the UCLASS_I2C_EMUL uclass, and emulates one i2c device. A
  19 * pointer to the device it emulates is in the 'dev' property of the emul device
  20 * uclass plat (struct i2c_emul_plat), put there by i2c_emul_find().
  21 * When sandbox wants an emulator for a device, it calls i2c_emul_find() which
  22 * searches for the emulator with the correct address. To find the device for an
  23 * emulator, call i2c_emul_get_device().
  24 *
  25 * The 'emul' node is in the UCLASS_I2C_EMUL_PARENT uclass. We use a separate
  26 * uclass so avoid having strange devices on the I2C bus.
  27 */
  28
  29struct udevice *i2c_emul_get_device(struct udevice *emul)
  30{
  31        struct i2c_emul_uc_plat *uc_plat = dev_get_uclass_plat(emul);
  32
  33        return uc_plat->dev;
  34}
  35
  36void i2c_emul_set_idx(struct udevice *dev, int emul_idx)
  37{
  38        struct dm_i2c_chip *plat = dev_get_parent_plat(dev);
  39
  40        plat->emul_idx = emul_idx;
  41}
  42
  43int i2c_emul_find(struct udevice *dev, struct udevice **emulp)
  44{
  45        struct i2c_emul_uc_plat *uc_plat;
  46        struct udevice *emul;
  47        int ret;
  48
  49        if (!CONFIG_IS_ENABLED(OF_PLATDATA)) {
  50                ret = uclass_find_device_by_phandle(UCLASS_I2C_EMUL, dev,
  51                                                    "sandbox,emul", &emul);
  52        } else {
  53                struct dm_i2c_chip *plat = dev_get_parent_plat(dev);
  54
  55                ret = device_get_by_ofplat_idx(plat->emul_idx, &emul);
  56        }
  57        if (ret) {
  58                log_err("No emulators for device '%s'\n", dev->name);
  59                return ret;
  60        }
  61        uc_plat = dev_get_uclass_plat(emul);
  62        uc_plat->dev = dev;
  63        *emulp = emul;
  64
  65        return device_probe(emul);
  66}
  67
  68UCLASS_DRIVER(i2c_emul) = {
  69        .id             = UCLASS_I2C_EMUL,
  70        .name           = "i2c_emul",
  71        .per_device_plat_auto   = sizeof(struct i2c_emul_uc_plat),
  72};
  73
  74/*
  75 * This uclass is a child of the i2c bus. Its plat is not defined here so
  76 * is defined by its parent, UCLASS_I2C, which uses struct dm_i2c_chip. See
  77 * per_child_plat_auto  in UCLASS_DRIVER(i2c).
  78 */
  79UCLASS_DRIVER(i2c_emul_parent) = {
  80        .id             = UCLASS_I2C_EMUL_PARENT,
  81        .name           = "i2c_emul_parent",
  82#if !CONFIG_IS_ENABLED(OF_PLATDATA)
  83        .post_bind      = dm_scan_fdt_dev,
  84#endif
  85};
  86
  87static const struct udevice_id i2c_emul_parent_ids[] = {
  88        { .compatible = "sandbox,i2c-emul-parent" },
  89        { }
  90};
  91
  92U_BOOT_DRIVER(sandbox_i2c_emul_parent) = {
  93        .name           = "sandbox_i2c_emul_parent",
  94        .id             = UCLASS_I2C_EMUL_PARENT,
  95        .of_match       = i2c_emul_parent_ids,
  96};
  97