From 21a99150a566b69edc7f3b9bc369bb4525e04acd Mon Sep 17 00:00:00 2001 From: Sam Shih Date: Fri, 2 Jun 2023 13:06:17 +0800 Subject: [PATCH] [spi-and-storage][999-2350-nvmem-core-Add-functions-to-make-number-reading-easy.patch] --- drivers/nvmem/core.c | 161 +++++++++++++++++++++++++++------ include/linux/nvmem-consumer.h | 15 +++ 2 files changed, 150 insertions(+), 26 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 19ac0d055..f65305b6d 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -1102,16 +1102,8 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) } EXPORT_SYMBOL_GPL(nvmem_cell_write); -/** - * nvmem_cell_read_u16() - Read a cell value as an u16 - * - * @dev: Device that requests the nvmem cell. - * @cell_id: Name of nvmem cell to read. - * @val: pointer to output value. - * - * Return: 0 on success or negative errno. - */ -int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val) +static int nvmem_cell_read_common(struct device *dev, const char *cell_id, + void *val, size_t count) { struct nvmem_cell *cell; void *buf; @@ -1126,21 +1118,50 @@ int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val) nvmem_cell_put(cell); return PTR_ERR(buf); } - if (len != sizeof(*val)) { + if (len != count) { kfree(buf); nvmem_cell_put(cell); return -EINVAL; } - memcpy(val, buf, sizeof(*val)); + memcpy(val, buf, count); kfree(buf); nvmem_cell_put(cell); return 0; } + +/** + * nvmem_cell_read_u8() - Read a cell value as a u8 + * + * @dev: Device that requests the nvmem cell. + * @cell_id: Name of nvmem cell to read. + * @val: pointer to output value. + * + * Return: 0 on success or negative errno. + */ +int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val) +{ + return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); +} +EXPORT_SYMBOL_GPL(nvmem_cell_read_u8); + +/** + * nvmem_cell_read_u16() - Read a cell value as a u16 + * + * @dev: Device that requests the nvmem cell. + * @cell_id: Name of nvmem cell to read. + * @val: pointer to output value. + * + * Return: 0 on success or negative errno. + */ +int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val) +{ + return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); +} EXPORT_SYMBOL_GPL(nvmem_cell_read_u16); /** - * nvmem_cell_read_u32() - Read a cell value as an u32 + * nvmem_cell_read_u32() - Read a cell value as a u32 * * @dev: Device that requests the nvmem cell. * @cell_id: Name of nvmem cell to read. @@ -1149,32 +1170,120 @@ EXPORT_SYMBOL_GPL(nvmem_cell_read_u16); * Return: 0 on success or negative errno. */ int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val) +{ + return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); +} +EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); + +/** + * nvmem_cell_read_u64() - Read a cell value as a u64 + * + * @dev: Device that requests the nvmem cell. + * @cell_id: Name of nvmem cell to read. + * @val: pointer to output value. + * + * Return: 0 on success or negative errno. + */ +int nvmem_cell_read_u64(struct device *dev, const char *cell_id, u64 *val) +{ + return nvmem_cell_read_common(dev, cell_id, val, sizeof(*val)); +} +EXPORT_SYMBOL_GPL(nvmem_cell_read_u64); + +static const void *nvmem_cell_read_variable_common(struct device *dev, + const char *cell_id, + size_t max_len, size_t *len) { struct nvmem_cell *cell; + int nbits; void *buf; - size_t len; cell = nvmem_cell_get(dev, cell_id); if (IS_ERR(cell)) - return PTR_ERR(cell); + return cell; - buf = nvmem_cell_read(cell, &len); - if (IS_ERR(buf)) { - nvmem_cell_put(cell); - return PTR_ERR(buf); - } - if (len != sizeof(*val)) { + nbits = cell->nbits; + buf = nvmem_cell_read(cell, len); + nvmem_cell_put(cell); + if (IS_ERR(buf)) + return buf; + + /* + * If nbits is set then nvmem_cell_read() can significantly exaggerate + * the length of the real data. Throw away the extra junk. + */ + if (nbits) + *len = DIV_ROUND_UP(nbits, 8); + + if (*len > max_len) { kfree(buf); - nvmem_cell_put(cell); - return -EINVAL; + return ERR_PTR(-ERANGE); } - memcpy(val, buf, sizeof(*val)); + + return buf; +} + +/** + * nvmem_cell_read_variable_le_u32() - Read up to 32-bits of data as a little endian number. + * + * @dev: Device that requests the nvmem cell. + * @cell_id: Name of nvmem cell to read. + * @val: pointer to output value. + * + * Return: 0 on success or negative errno. + */ +int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id, + u32 *val) +{ + size_t len; + const u8 *buf; + int i; + + buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + /* Copy w/ implicit endian conversion */ + *val = 0; + for (i = 0; i < len; i++) + *val |= buf[i] << (8 * i); kfree(buf); - nvmem_cell_put(cell); + return 0; } -EXPORT_SYMBOL_GPL(nvmem_cell_read_u32); +EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u32); + +/** + * nvmem_cell_read_variable_le_u64() - Read up to 64-bits of data as a little endian number. + * + * @dev: Device that requests the nvmem cell. + * @cell_id: Name of nvmem cell to read. + * @val: pointer to output value. + * + * Return: 0 on success or negative errno. + */ +int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id, + u64 *val) +{ + size_t len; + const u8 *buf; + int i; + + buf = nvmem_cell_read_variable_common(dev, cell_id, sizeof(*val), &len); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + /* Copy w/ implicit endian conversion */ + *val = 0; + for (i = 0; i < len; i++) + *val |= (uint64_t)buf[i] << (8 * i); + + kfree(buf); + + return 0; +} +EXPORT_SYMBOL_GPL(nvmem_cell_read_variable_le_u64); /** * nvmem_device_cell_read() - Read a given nvmem device and cell diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h index 0f490b288..227b93158 100644 --- a/include/linux/nvmem-consumer.h +++ b/include/linux/nvmem-consumer.h @@ -64,6 +64,10 @@ void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len); int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len); int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val); int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val); +int nvmem_cell_read_variable_le_u32(struct device *dev, const char *cell_id, + u32 *val); +int nvmem_cell_read_variable_le_u64(struct device *dev, const char *cell_id, + u64 *val); /* direct nvmem device read/write interface */ struct nvmem_device *nvmem_device_get(struct device *dev, const char *name); @@ -135,6 +139,17 @@ static inline int nvmem_cell_read_u32(struct device *dev, { return -EOPNOTSUPP; } +static inline int nvmem_cell_read_variable_le_u32(struct device *dev, + const char *cell_id, u32 *val) +{ + return -ENOSYS; +} + +static inline int nvmem_cell_read_variable_le_u64(struct device *dev, + const char *cell_id, u64 *val); +{ + return -ENOSYS; +} static inline struct nvmem_device *nvmem_device_get(struct device *dev, const char *name) -- 2.34.1