diff --git a/MAINTAINERS b/MAINTAINERS index 28e4d38238..4ccefb7a11 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1091,6 +1091,13 @@ F: cmd/nvme.c F: include/nvme.h F: doc/develop/driver-model/nvme.rst +NVMEM +M: Sean Anderson +S: Maintained +F: doc/api/nvmem.rst +F: drivers/misc/nvmem.c +F: include/nvmem.h + NXP C45 TJA11XX PHY DRIVER M: Radu Pirea S: Maintained diff --git a/doc/api/index.rst b/doc/api/index.rst index 72fea981b7..a9338cfef9 100644 --- a/doc/api/index.rst +++ b/doc/api/index.rst @@ -14,6 +14,7 @@ U-Boot API documentation linker_lists lmb logging + nvmem pinctrl rng sandbox diff --git a/doc/api/nvmem.rst b/doc/api/nvmem.rst new file mode 100644 index 0000000000..d923784652 --- /dev/null +++ b/doc/api/nvmem.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +NVMEM API +========= + +.. kernel-doc:: include/nvmem.h + :doc: Design + +.. kernel-doc:: include/nvmem.h + :internal: diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index 419ddd31c0..f368d52c56 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -43,6 +43,22 @@ config VPL_MISC set of generic read, write and ioctl methods may be used to access the device. +config NVMEM + bool "NVMEM support" + help + This adds support for a common interface to different types of + non-volatile memory. Consumers can use nvmem-cells properties to look + up hardware configuration data such as MAC addresses and calibration + settings. + +config SPL_NVMEM + bool "NVMEM support in SPL" + help + This adds support for a common interface to different types of + non-volatile memory. Consumers can use nvmem-cells properties to look + up hardware configuration data such as MAC addresses and calibration + settings. + config ALTERA_SYSID bool "Altera Sysid support" depends on MISC diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 7a6047f64f..6c79030893 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -4,6 +4,7 @@ # Wolfgang Denk, DENX Software Engineering, wd@denx.de. obj-$(CONFIG_$(SPL_TPL_)MISC) += misc-uclass.o +obj-$(CONFIG_$(SPL_TPL_)NVMEM) += nvmem.o obj-$(CONFIG_$(SPL_TPL_)CROS_EC) += cros_ec.o obj-$(CONFIG_$(SPL_TPL_)CROS_EC_SANDBOX) += cros_ec_sandbox.o diff --git a/drivers/misc/nvmem.c b/drivers/misc/nvmem.c new file mode 100644 index 0000000000..5a2bd1f9f7 --- /dev/null +++ b/drivers/misc/nvmem.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2022 Sean Anderson + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +int nvmem_cell_read(struct nvmem_cell *cell, void *buf, size_t size) +{ + dev_dbg(cell->nvmem, "%s: off=%u size=%zu\n", __func__, cell->offset, size); + if (size != cell->size) + return -EINVAL; + + switch (cell->nvmem->driver->id) { + case UCLASS_I2C_EEPROM: + return i2c_eeprom_read(cell->nvmem, cell->offset, buf, size); + case UCLASS_MISC: { + int ret = misc_read(cell->nvmem, cell->offset, buf, size); + + if (ret < 0) + return ret; + if (ret != size) + return -EIO; + return 0; + } + case UCLASS_RTC: + return dm_rtc_read(cell->nvmem, cell->offset, buf, size); + default: + return -ENOSYS; + } +} + +int nvmem_cell_write(struct nvmem_cell *cell, const void *buf, size_t size) +{ + dev_dbg(cell->nvmem, "%s: off=%u size=%zu\n", __func__, cell->offset, size); + if (size != cell->size) + return -EINVAL; + + switch (cell->nvmem->driver->id) { + case UCLASS_I2C_EEPROM: + return i2c_eeprom_write(cell->nvmem, cell->offset, buf, size); + case UCLASS_MISC: { + int ret = misc_write(cell->nvmem, cell->offset, buf, size); + + if (ret < 0) + return ret; + if (ret != size) + return -EIO; + return 0; + } + case UCLASS_RTC: + return dm_rtc_write(cell->nvmem, cell->offset, buf, size); + default: + return -ENOSYS; + } +} + +/** + * nvmem_get_device() - Get an nvmem device for a cell + * @node: ofnode of the nvmem device + * @cell: Cell to look up + * + * Try to find a nvmem-compatible device by going through the nvmem interfaces. + * + * Return: + * * 0 on success + * * -ENODEV if we didn't find anything + * * A negative error if there was a problem looking up the device + */ +static int nvmem_get_device(ofnode node, struct nvmem_cell *cell) +{ + int i, ret; + enum uclass_id ids[] = { + UCLASS_I2C_EEPROM, + UCLASS_MISC, + UCLASS_RTC, + }; + + for (i = 0; i < ARRAY_SIZE(ids); i++) { + ret = uclass_get_device_by_ofnode(ids[i], node, &cell->nvmem); + if (!ret) + return 0; + if (ret != -ENODEV && ret != -EPFNOSUPPORT) + return ret; + } + + return -ENODEV; +} + +int nvmem_cell_get_by_index(struct udevice *dev, int index, + struct nvmem_cell *cell) +{ + fdt_addr_t offset; + fdt_size_t size = FDT_SIZE_T_NONE; + int ret; + struct ofnode_phandle_args args; + + dev_dbg(dev, "%s: index=%d\n", __func__, index); + + ret = dev_read_phandle_with_args(dev, "nvmem-cells", NULL, 0, index, + &args); + if (ret) + return ret; + + ret = nvmem_get_device(ofnode_get_parent(args.node), cell); + if (ret) + return ret; + + offset = ofnode_get_addr_size_index_notrans(args.node, 0, &size); + if (offset == FDT_ADDR_T_NONE || size == FDT_SIZE_T_NONE) { + dev_dbg(cell->nvmem, "missing address or size for %s\n", + ofnode_get_name(args.node)); + return -EINVAL; + } + + cell->offset = offset; + cell->size = size; + return 0; +} + +int nvmem_cell_get_by_name(struct udevice *dev, const char *name, + struct nvmem_cell *cell) +{ + int index; + + dev_dbg(dev, "%s, name=%s\n", __func__, name); + + index = dev_read_stringlist_search(dev, "nvmem-cell-names", name); + if (index < 0) + return index; + + return nvmem_cell_get_by_index(dev, index, cell); +} diff --git a/include/nvmem.h b/include/nvmem.h new file mode 100644 index 0000000000..822e698bdd --- /dev/null +++ b/include/nvmem.h @@ -0,0 +1,134 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c) 2022 Sean Anderson + */ + +#ifndef NVMEM_H +#define NVMEM_H + +/** + * DOC: Design + * + * The NVMEM subsystem is a "meta-uclass" in that it abstracts over several + * different uclasses all with read/write APIs. One approach to implementing + * this could be to add a new sub-device for each nvmem-style device of + * UCLASS_NVMEM. This subsystem has taken the approach of using the existing + * access methods (i2c_eeprom_write, misc_write, etc.) directly. This has the + * advantage of not requiring an extra device/driver, saving on binary size and + * runtime memory usage. On the other hand, it is not idiomatic. Similar + * efforts should generally use a new uclass. + */ + +/** + * struct nvmem_cell - One datum within non-volatile memory + * @nvmem: The backing storage device + * @offset: The offset of the cell from the start of @nvmem + * @size: The size of the cell, in bytes + */ +struct nvmem_cell { + struct udevice *nvmem; + unsigned int offset; + size_t size; +}; + +struct udevice; + +#if CONFIG_IS_ENABLED(NVMEM) + +/** + * nvmem_cell_read() - Read the value of an nvmem cell + * @cell: The nvmem cell to read + * @buf: The buffer to read into + * @size: The size of @buf + * + * Return: + * * 0 on success + * * -EINVAL if @buf is not the same size as @cell. + * * -ENOSYS if CONFIG_NVMEM is disabled + * * A negative error if there was a problem reading the underlying storage + */ +int nvmem_cell_read(struct nvmem_cell *cell, void *buf, size_t size); + +/** + * nvmem_cell_write() - Write a value to an nvmem cell + * @cell: The nvmem cell to write + * @buf: The buffer to write from + * @size: The size of @buf + * + * Return: + * * 0 on success + * * -EINVAL if @buf is not the same size as @cell + * * -ENOSYS if @cell is read-only, or if CONFIG_NVMEM is disabled + * * A negative error if there was a problem writing the underlying storage + */ +int nvmem_cell_write(struct nvmem_cell *cell, const void *buf, size_t size); + +/** + * nvmem_cell_get_by_index() - Get an nvmem cell from a given device and index + * @dev: The device that uses the nvmem cell + * @index: The index of the cell in nvmem-cells + * @cell: The cell to initialize + * + * Look up the nvmem cell referenced by the phandle at @index in nvmem-cells in + * @dev. + * + * Return: + * * 0 on success + * * -EINVAL if the regs property is missing, empty, or undersized + * * -ENODEV if the nvmem device is missing or unimplemented + * * -ENOSYS if CONFIG_NVMEM is disabled + * * A negative error if there was a problem reading nvmem-cells or getting the + * device + */ +int nvmem_cell_get_by_index(struct udevice *dev, int index, + struct nvmem_cell *cell); + +/** + * nvmem_cell_get_by_name() - Get an nvmem cell from a given device and name + * @dev: The device that uses the nvmem cell + * @name: The name of the nvmem cell + * @cell: The cell to initialize + * + * Look up the nvmem cell referenced by @name in the nvmem-cell-names property + * of @dev. + * + * Return: + * * 0 on success + * * -EINVAL if the regs property is missing, empty, or undersized + * * -ENODEV if the nvmem device is missing or unimplemented + * * -ENODATA if @name is not in nvmem-cell-names + * * -ENOSYS if CONFIG_NVMEM is disabled + * * A negative error if there was a problem reading nvmem-cell-names, + * nvmem-cells, or getting the device + */ +int nvmem_cell_get_by_name(struct udevice *dev, const char *name, + struct nvmem_cell *cell); + +#else /* CONFIG_NVMEM */ + +static inline int nvmem_cell_read(struct nvmem_cell *cell, void *buf, int size) +{ + return -ENOSYS; +} + +static inline int nvmem_cell_write(struct nvmem_cell *cell, const void *buf, + int size) +{ + return -ENOSYS; +} + +static inline int nvmem_cell_get_by_index(struct udevice *dev, int index, + struct nvmem_cell *cell) +{ + return -ENOSYS; +} + +static inline int nvmem_cell_get_by_name(struct udevice *dev, const char *name, + struct nvmem_cell *cell) +{ + return -ENOSYS; +} + +#endif /* CONFIG_NVMEM */ + +#endif /* NVMEM_H */