From 266570f496b90dea8fda893c2cf7c28d63ae2bd9 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 4 Apr 2023 18:21:21 +0100 Subject: nvmem: core: introduce NVMEM layouts NVMEM layouts are used to generate NVMEM cells during runtime. Think of an EEPROM with a well-defined conent. For now, the content can be described by a device tree or a board file. But this only works if the offsets and lengths are static and don't change. One could also argue that putting the layout of the EEPROM in the device tree is the wrong place. Instead, the device tree should just have a specific compatible string. Right now there are two use cases: (1) The NVMEM cell needs special processing. E.g. if it only specifies a base MAC address offset and you need to add an offset, or it needs to parse a MAC from ASCII format or some proprietary format. (Post processing of cells is added in a later commit). (2) u-boot environment parsing. The cells don't have a particular offset but it needs parsing the content to determine the offsets and length. Co-developed-by: Miquel Raynal Signed-off-by: Miquel Raynal Signed-off-by: Michael Walle Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-14-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- include/linux/nvmem-provider.h | 51 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) (limited to 'include/linux/nvmem-provider.h') diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index 0262b86194eb..535c5f9f3309 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -88,6 +88,7 @@ struct nvmem_cell_info { * @stride: Minimum read/write access stride. * @priv: User context passed to read/write callbacks. * @ignore_wp: Write Protect pin is managed by the provider. + * @layout: Fixed layout associated with this nvmem device. * * Note: A default "nvmem" name will be assigned to the device if * no name is specified in its configuration. In such case "" is @@ -109,6 +110,7 @@ struct nvmem_config { bool read_only; bool root_only; bool ignore_wp; + struct nvmem_layout *layout; struct device_node *of_node; bool no_of_node; nvmem_reg_read_t reg_read; @@ -142,6 +144,33 @@ struct nvmem_cell_table { struct list_head node; }; +/** + * struct nvmem_layout - NVMEM layout definitions + * + * @name: Layout name. + * @of_match_table: Open firmware match table. + * @add_cells: Will be called if a nvmem device is found which + * has this layout. The function will add layout + * specific cells with nvmem_add_one_cell(). + * @owner: Pointer to struct module. + * @node: List node. + * + * A nvmem device can hold a well defined structure which can just be + * evaluated during runtime. For example a TLV list, or a list of "name=val" + * pairs. A nvmem layout can parse the nvmem device and add appropriate + * cells. + */ +struct nvmem_layout { + const char *name; + const struct of_device_id *of_match_table; + int (*add_cells)(struct device *dev, struct nvmem_device *nvmem, + struct nvmem_layout *layout); + + /* private */ + struct module *owner; + struct list_head node; +}; + #if IS_ENABLED(CONFIG_NVMEM) struct nvmem_device *nvmem_register(const struct nvmem_config *cfg); @@ -156,6 +185,14 @@ void nvmem_del_cell_table(struct nvmem_cell_table *table); int nvmem_add_one_cell(struct nvmem_device *nvmem, const struct nvmem_cell_info *info); +int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner); +#define nvmem_layout_register(layout) \ + __nvmem_layout_register(layout, THIS_MODULE) +void nvmem_layout_unregister(struct nvmem_layout *layout); + +const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem, + struct nvmem_layout *layout); + #else static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c) @@ -179,5 +216,19 @@ static inline int nvmem_add_one_cell(struct nvmem_device *nvmem, return -EOPNOTSUPP; } +static inline int nvmem_layout_register(struct nvmem_layout *layout) +{ + return -EOPNOTSUPP; +} + +static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {} + +static inline const void * +nvmem_layout_get_match_data(struct nvmem_device *nvmem, + struct nvmem_layout *layout) +{ + return NULL; +} + #endif /* CONFIG_NVMEM */ #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ -- cgit v1.2.3-70-g09d2 From 345ec382cd4b736c36e01f155d08c913b225b736 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 4 Apr 2023 18:21:24 +0100 Subject: nvmem: core: add per-cell post processing Instead of relying on the name the consumer is using for the cell, like it is done for the nvmem .cell_post_process configuration parameter, provide a per-cell post processing hook. This can then be populated by the NVMEM provider (or the NVMEM layout) when adding the cell. Signed-off-by: Michael Walle Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-17-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 17 +++++++++++++++++ include/linux/nvmem-provider.h | 3 +++ 2 files changed, 20 insertions(+) (limited to 'include/linux/nvmem-provider.h') diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 49b4bbaf59e8..0708f9f27898 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -54,6 +54,7 @@ struct nvmem_cell_entry { int bytes; int bit_offset; int nbits; + nvmem_cell_post_process_t read_post_process; struct device_node *np; struct nvmem_device *nvmem; struct list_head node; @@ -470,6 +471,7 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem, cell->offset = info->offset; cell->bytes = info->bytes; cell->name = info->name; + cell->read_post_process = info->read_post_process; cell->bit_offset = info->bit_offset; cell->nbits = info->nbits; @@ -1563,6 +1565,13 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem, if (cell->bit_offset || cell->nbits) nvmem_shift_read_buffer_in_place(cell, buf); + if (cell->read_post_process) { + rc = cell->read_post_process(nvmem->priv, id, index, + cell->offset, buf, cell->bytes); + if (rc) + return rc; + } + if (nvmem->cell_post_process) { rc = nvmem->cell_post_process(nvmem->priv, id, index, cell->offset, buf, cell->bytes); @@ -1671,6 +1680,14 @@ static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, si (cell->bit_offset == 0 && len != cell->bytes)) return -EINVAL; + /* + * Any cells which have a read_post_process hook are read-only because + * we cannot reverse the operation and it might affect other cells, + * too. + */ + if (cell->read_post_process) + return -EINVAL; + if (cell->bit_offset || cell->nbits) { buf = nvmem_cell_prepare_write_buffer(cell, buf, len); if (IS_ERR(buf)) diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index 535c5f9f3309..3bfc23553a9e 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -54,6 +54,8 @@ struct nvmem_keepout { * @bit_offset: Bit offset if cell is smaller than a byte. * @nbits: Number of bits. * @np: Optional device_node pointer. + * @read_post_process: Callback for optional post processing of cell data + * on reads. */ struct nvmem_cell_info { const char *name; @@ -62,6 +64,7 @@ struct nvmem_cell_info { unsigned int bit_offset; unsigned int nbits; struct device_node *np; + nvmem_cell_post_process_t read_post_process; }; /** -- cgit v1.2.3-70-g09d2 From de12c9691501ccba41a154c223869f82be4c12fd Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 4 Apr 2023 18:21:25 +0100 Subject: nvmem: core: allow to modify a cell before adding it Provide a way to modify a cell before it will get added. This is useful to attach a custom post processing hook via a layout. Signed-off-by: Michael Walle Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-18-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 4 ++++ include/linux/nvmem-provider.h | 5 +++++ 2 files changed, 9 insertions(+) (limited to 'include/linux/nvmem-provider.h') diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 0708f9f27898..f43025ad315b 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -695,6 +695,7 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem) static int nvmem_add_cells_from_of(struct nvmem_device *nvmem) { + struct nvmem_layout *layout = nvmem->layout; struct device *dev = &nvmem->dev; struct device_node *child; const __be32 *addr; @@ -724,6 +725,9 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem) info.np = of_node_get(child); + if (layout && layout->fixup_cell_info) + layout->fixup_cell_info(nvmem, layout, &info); + ret = nvmem_add_one_cell(nvmem, &info); kfree(info.name); if (ret) { diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index 3bfc23553a9e..be81cc88eabc 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -155,6 +155,8 @@ struct nvmem_cell_table { * @add_cells: Will be called if a nvmem device is found which * has this layout. The function will add layout * specific cells with nvmem_add_one_cell(). + * @fixup_cell_info: Will be called before a cell is added. Can be + * used to modify the nvmem_cell_info. * @owner: Pointer to struct module. * @node: List node. * @@ -168,6 +170,9 @@ struct nvmem_layout { const struct of_device_id *of_match_table; int (*add_cells)(struct device *dev, struct nvmem_device *nvmem, struct nvmem_layout *layout); + void (*fixup_cell_info)(struct nvmem_device *nvmem, + struct nvmem_layout *layout, + struct nvmem_cell_info *cell); /* private */ struct module *owner; -- cgit v1.2.3-70-g09d2 From 011e40a166fdaa65fb9946b7cd91efec85b70dbb Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 4 Apr 2023 18:21:27 +0100 Subject: nvmem: cell: drop global cell_post_process There are no users anymore for the global cell_post_process callback anymore. New users should use proper nvmem layouts. Signed-off-by: Michael Walle Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-20-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 9 --------- include/linux/nvmem-provider.h | 2 -- 2 files changed, 11 deletions(-) (limited to 'include/linux/nvmem-provider.h') diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index f43025ad315b..fccb2728193a 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -39,7 +39,6 @@ struct nvmem_device { unsigned int nkeepout; nvmem_reg_read_t reg_read; nvmem_reg_write_t reg_write; - nvmem_cell_post_process_t cell_post_process; struct gpio_desc *wp_gpio; struct nvmem_layout *layout; void *priv; @@ -903,7 +902,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) nvmem->type = config->type; nvmem->reg_read = config->reg_read; nvmem->reg_write = config->reg_write; - nvmem->cell_post_process = config->cell_post_process; nvmem->keepout = config->keepout; nvmem->nkeepout = config->nkeepout; if (config->of_node) @@ -1576,13 +1574,6 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem, return rc; } - if (nvmem->cell_post_process) { - rc = nvmem->cell_post_process(nvmem->priv, id, index, - cell->offset, buf, cell->bytes); - if (rc) - return rc; - } - if (len) *len = cell->bytes; diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index be81cc88eabc..d3d7af86a283 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -85,7 +85,6 @@ struct nvmem_cell_info { * @no_of_node: Device should not use the parent's of_node even if it's !NULL. * @reg_read: Callback to read data. * @reg_write: Callback to write data. - * @cell_post_process: Callback for vendor specific post processing of cell data * @size: Device size. * @word_size: Minimum read/write access granularity. * @stride: Minimum read/write access stride. @@ -118,7 +117,6 @@ struct nvmem_config { bool no_of_node; nvmem_reg_read_t reg_read; nvmem_reg_write_t reg_write; - nvmem_cell_post_process_t cell_post_process; int size; int word_size; int stride; -- cgit v1.2.3-70-g09d2 From 8a134fd9f9323f4c39ec27055b3d3723cfb5c1e9 Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Tue, 4 Apr 2023 18:21:28 +0100 Subject: nvmem: core: provide own priv pointer in post process callback It doesn't make any more sense to have a opaque pointer set up by the nvmem device. Usually, the layout isn't associated with a particular nvmem device. Instead, let the caller who set the post process callback provide the priv pointer. Signed-off-by: Michael Walle Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-21-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 4 +++- include/linux/nvmem-provider.h | 5 ++++- 2 files changed, 7 insertions(+), 2 deletions(-) (limited to 'include/linux/nvmem-provider.h') diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index fccb2728193a..212c5ba5789f 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -54,6 +54,7 @@ struct nvmem_cell_entry { int bit_offset; int nbits; nvmem_cell_post_process_t read_post_process; + void *priv; struct device_node *np; struct nvmem_device *nvmem; struct list_head node; @@ -471,6 +472,7 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem, cell->bytes = info->bytes; cell->name = info->name; cell->read_post_process = info->read_post_process; + cell->priv = info->priv; cell->bit_offset = info->bit_offset; cell->nbits = info->nbits; @@ -1568,7 +1570,7 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem, nvmem_shift_read_buffer_in_place(cell, buf); if (cell->read_post_process) { - rc = cell->read_post_process(nvmem->priv, id, index, + rc = cell->read_post_process(cell->priv, id, index, cell->offset, buf, cell->bytes); if (rc) return rc; diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index d3d7af86a283..0cf9f9490514 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -20,7 +20,8 @@ typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset, void *val, size_t bytes); /* used for vendor specific post processing of cell data */ typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, int index, - unsigned int offset, void *buf, size_t bytes); + unsigned int offset, void *buf, + size_t bytes); enum nvmem_type { NVMEM_TYPE_UNKNOWN = 0, @@ -56,6 +57,7 @@ struct nvmem_keepout { * @np: Optional device_node pointer. * @read_post_process: Callback for optional post processing of cell data * on reads. + * @priv: Opaque data passed to the read_post_process hook. */ struct nvmem_cell_info { const char *name; @@ -65,6 +67,7 @@ struct nvmem_cell_info { unsigned int nbits; struct device_node *np; nvmem_cell_post_process_t read_post_process; + void *priv; }; /** -- cgit v1.2.3-70-g09d2 From 55d4980ce55b6bb4be66877de4dbec513911b988 Mon Sep 17 00:00:00 2001 From: Rafał Miłecki Date: Tue, 4 Apr 2023 18:21:42 +0100 Subject: nvmem: core: support specifying both: cell raw data & post read lengths MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Callback .read_post_process() is designed to modify raw cell content before providing it to the consumer. So far we were dealing with modifications that didn't affect cell size (length). In some cases however cell content needs to be reformatted and resized. It's required e.g. to provide properly formatted MAC address in case it's stored in a non-binary format (e.g. using ASCII). There were few discussions how to optimally handle that. Following possible solutions were considered: 1. Allow .read_post_process() to realloc (resize) content buffer 2. Allow .read_post_process() to adjust (decrease) just buffer length 3. Register NVMEM cells using post-read sizes The preferred solution was the last one. The problem is that simply adjusting "bytes" in NVMEM providers would result in core code NOT passing whole raw data to .read_post_process() callbacks. It means callback functions couldn't do their job without somehow manually reading original cell content on their own. This patch deals with that by registering NVMEM cells with both lengths: raw content one and post read one. It allows: 1. Core code to read whole raw cell content 2. Callbacks to return content they want Signed-off-by: Rafał Miłecki Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-35-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 11 +++++++---- include/linux/nvmem-provider.h | 2 ++ 2 files changed, 9 insertions(+), 4 deletions(-) (limited to 'include/linux/nvmem-provider.h') diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 212c5ba5789f..a62973d010ff 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -50,6 +50,7 @@ struct nvmem_device { struct nvmem_cell_entry { const char *name; int offset; + size_t raw_len; int bytes; int bit_offset; int nbits; @@ -469,6 +470,7 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem, { cell->nvmem = nvmem; cell->offset = info->offset; + cell->raw_len = info->raw_len ?: info->bytes; cell->bytes = info->bytes; cell->name = info->name; cell->read_post_process = info->read_post_process; @@ -1560,7 +1562,7 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem, { int rc; - rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes); + rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->raw_len); if (rc) return rc; @@ -1571,7 +1573,7 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem, if (cell->read_post_process) { rc = cell->read_post_process(cell->priv, id, index, - cell->offset, buf, cell->bytes); + cell->offset, buf, cell->raw_len); if (rc) return rc; } @@ -1594,14 +1596,15 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem, */ void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len) { - struct nvmem_device *nvmem = cell->entry->nvmem; + struct nvmem_cell_entry *entry = cell->entry; + struct nvmem_device *nvmem = entry->nvmem; u8 *buf; int rc; if (!nvmem) return ERR_PTR(-EINVAL); - buf = kzalloc(cell->entry->bytes, GFP_KERNEL); + buf = kzalloc(max_t(size_t, entry->raw_len, entry->bytes), GFP_KERNEL); if (!buf) return ERR_PTR(-ENOMEM); diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index 0cf9f9490514..8ffb42ba0f62 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -51,6 +51,7 @@ struct nvmem_keepout { * struct nvmem_cell_info - NVMEM cell description * @name: Name. * @offset: Offset within the NVMEM device. + * @raw_len: Length of raw data (without post processing). * @bytes: Length of the cell. * @bit_offset: Bit offset if cell is smaller than a byte. * @nbits: Number of bits. @@ -62,6 +63,7 @@ struct nvmem_keepout { struct nvmem_cell_info { const char *name; unsigned int offset; + size_t raw_len; unsigned int bytes; unsigned int bit_offset; unsigned int nbits; -- cgit v1.2.3-70-g09d2 From 814c978f02db17f16e6aa2efa2a929372f06da09 Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Tue, 4 Apr 2023 18:21:44 +0100 Subject: nvmem: Add macro to register nvmem layout drivers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Provide a module_nvmem_layout_driver() macro at the end of the nvmem-provider.h header to reduce the boilerplate when registering nvmem layout drivers. Suggested-by: Srinivas Kandagatla Signed-off-by: Miquel Raynal Acked-by: Rafał Miłecki Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-37-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- include/linux/nvmem-provider.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/nvmem-provider.h') diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h index 8ffb42ba0f62..dae26295e6be 100644 --- a/include/linux/nvmem-provider.h +++ b/include/linux/nvmem-provider.h @@ -9,6 +9,7 @@ #ifndef _LINUX_NVMEM_PROVIDER_H #define _LINUX_NVMEM_PROVIDER_H +#include #include #include #include @@ -242,4 +243,9 @@ nvmem_layout_get_match_data(struct nvmem_device *nvmem, } #endif /* CONFIG_NVMEM */ + +#define module_nvmem_layout_driver(__layout_driver) \ + module_driver(__layout_driver, nvmem_layout_register, \ + nvmem_layout_unregister) + #endif /* ifndef _LINUX_NVMEM_PROVIDER_H */ -- cgit v1.2.3-70-g09d2