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
nvmem_cell_read(struct nvmem_cell * cell,void * buf,size_t size)16 int 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
nvmem_cell_write(struct nvmem_cell * cell,const void * buf,size_t size)41 int 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 */
nvmem_get_device(ofnode node,struct nvmem_cell * cell)78 static 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
nvmem_cell_get_by_index(struct udevice * dev,int index,struct nvmem_cell * cell)98 int 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
nvmem_cell_get_by_name(struct udevice * dev,const char * name,struct nvmem_cell * cell)129 int 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