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