| From 21a99150a566b69edc7f3b9bc369bb4525e04acd Mon Sep 17 00:00:00 2001 |
| From: Sam Shih <sam.shih@mediatek.com> |
| 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 |
| |