1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2022 Sean Anderson <sean.anderson@seco.com>
4 */
5
6#include <i2c_eeprom.h>
7#include <linker_lists.h>
8#include <misc.h>
9#include <nvmem.h>
10#include <rtc.h>
11#include <dm/device_compat.h>
12#include <dm/ofnode.h>
13#include <dm/read.h>
14#include <dm/uclass.h>
15
16int nvmem_cell_read(struct nvmem_cell *cell, void *buf, size_t size)
17{
18	dev_dbg(cell->nvmem, "%s: off=%u size=%zu\n", __func__, cell->offset, size);
19	if (size != cell->size)
20		return -EINVAL;
21
22	switch (cell->nvmem->driver->id) {
23	case UCLASS_I2C_EEPROM:
24		return i2c_eeprom_read(cell->nvmem, cell->offset, buf, size);
25	case UCLASS_MISC: {
26		int ret = misc_read(cell->nvmem, cell->offset, buf, size);
27
28		if (ret < 0)
29			return ret;
30		if (ret != size)
31			return -EIO;
32		return 0;
33	}
34	case UCLASS_RTC:
35		return dm_rtc_read(cell->nvmem, cell->offset, buf, size);
36	default:
37		return -ENOSYS;
38	}
39}
40
41int nvmem_cell_write(struct nvmem_cell *cell, const void *buf, size_t size)
42{
43	dev_dbg(cell->nvmem, "%s: off=%u size=%zu\n", __func__, cell->offset, size);
44	if (size != cell->size)
45		return -EINVAL;
46
47	switch (cell->nvmem->driver->id) {
48	case UCLASS_I2C_EEPROM:
49		return i2c_eeprom_write(cell->nvmem, cell->offset, buf, size);
50	case UCLASS_MISC: {
51		int ret = misc_write(cell->nvmem, cell->offset, buf, size);
52
53		if (ret < 0)
54			return ret;
55		if (ret != size)
56			return -EIO;
57		return 0;
58	}
59	case UCLASS_RTC:
60		return dm_rtc_write(cell->nvmem, cell->offset, buf, size);
61	default:
62		return -ENOSYS;
63	}
64}
65
66/**
67 * nvmem_get_device() - Get an nvmem device for a cell
68 * @node: ofnode of the nvmem device
69 * @cell: Cell to look up
70 *
71 * Try to find a nvmem-compatible device by going through the nvmem interfaces.
72 *
73 * Return:
74 * * 0 on success
75 * * -ENODEV if we didn't find anything
76 * * A negative error if there was a problem looking up the device
77 */
78static int nvmem_get_device(ofnode node, struct nvmem_cell *cell)
79{
80	int i, ret;
81	enum uclass_id ids[] = {
82		UCLASS_I2C_EEPROM,
83		UCLASS_MISC,
84		UCLASS_RTC,
85	};
86
87	for (i = 0; i < ARRAY_SIZE(ids); i++) {
88		ret = uclass_get_device_by_ofnode(ids[i], node, &cell->nvmem);
89		if (!ret)
90			return 0;
91		if (ret != -ENODEV && ret != -EPFNOSUPPORT)
92			return ret;
93	}
94
95	return -ENODEV;
96}
97
98int nvmem_cell_get_by_index(struct udevice *dev, int index,
99			    struct nvmem_cell *cell)
100{
101	fdt_addr_t offset;
102	fdt_size_t size = FDT_SIZE_T_NONE;
103	int ret;
104	struct ofnode_phandle_args args;
105
106	dev_dbg(dev, "%s: index=%d\n", __func__, index);
107
108	ret = dev_read_phandle_with_args(dev, "nvmem-cells", NULL, 0, index,
109					 &args);
110	if (ret)
111		return ret;
112
113	ret = nvmem_get_device(ofnode_get_parent(args.node), cell);
114	if (ret)
115		return ret;
116
117	offset = ofnode_get_addr_size_index_notrans(args.node, 0, &size);
118	if (offset == FDT_ADDR_T_NONE || size == FDT_SIZE_T_NONE) {
119		dev_dbg(cell->nvmem, "missing address or size for %s\n",
120			ofnode_get_name(args.node));
121		return -EINVAL;
122	}
123
124	cell->offset = offset;
125	cell->size = size;
126	return 0;
127}
128
129int nvmem_cell_get_by_name(struct udevice *dev, const char *name,
130			   struct nvmem_cell *cell)
131{
132	int index;
133
134	dev_dbg(dev, "%s, name=%s\n", __func__, name);
135
136	index = dev_read_stringlist_search(dev, "nvmem-cell-names", name);
137	if (index < 0)
138		return index;
139
140	return nvmem_cell_get_by_index(dev, index, cell);
141}
142