| Message ID | 20220825214423.903672-8-michael@walle.cc (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | nvmem: core: introduce NVMEM layouts | expand |
On 25/08/2022 22:44, Michael Walle wrote: > 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 <michael@walle.cc> > --- > drivers/nvmem/core.c | 16 ++++++++++++++++ > include/linux/nvmem-consumer.h | 5 +++++ > 2 files changed, 21 insertions(+) > > diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c > index 5357fc378700..cbfbe6264e6c 100644 > --- a/drivers/nvmem/core.c > +++ b/drivers/nvmem/core.c > @@ -52,6 +52,7 @@ struct nvmem_cell_entry { > int bytes; > int bit_offset; > int nbits; > + nvmem_cell_post_process_t post_process; two post_processing callbacks for cells is confusing tbh, we could totally move to use of cell->post_process. one idea is to point cell->post_process to nvmem->cell_post_process during cell creation time which should clean this up a bit. Other option is to move to using layouts for every thing. prefixing post_process with read should also make it explicit that this callback is very specific to reads only. > struct device_node *np; > struct nvmem_device *nvmem; > struct list_head node; > @@ -468,6 +469,7 @@ 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->post_process = info->post_process; > > cell->bit_offset = info->bit_offset; > cell->nbits = info->nbits; > @@ -1500,6 +1502,13 @@ 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->post_process) { > + rc = cell->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); > @@ -1608,6 +1617,13 @@ 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 post_process hook are read-only because we > + * cannot reverse the operation and it might affect other cells, too. > + */ > + if (cell->post_process) > + return -EINVAL; Post process was always implicitly for reads only, this check should also tie the loose ends of cell_post_processing callback. --srini > + > 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-consumer.h b/include/linux/nvmem-consumer.h > index 980f9c9ac0bc..761b8ef78adc 100644 > --- a/include/linux/nvmem-consumer.h > +++ b/include/linux/nvmem-consumer.h > @@ -19,6 +19,10 @@ struct device_node; > struct nvmem_cell; > struct nvmem_device; > > +/* duplicated from nvmem-provider.h */ > +typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, int index, > + unsigned int offset, void *buf, size_t bytes); > + > struct nvmem_cell_info { > const char *name; > unsigned int offset; > @@ -26,6 +30,7 @@ struct nvmem_cell_info { > unsigned int bit_offset; > unsigned int nbits; > struct device_node *np; > + nvmem_cell_post_process_t post_process; > }; > > /**
Hi, Am 2022-08-30 15:37, schrieb Srinivas Kandagatla: > On 25/08/2022 22:44, Michael Walle wrote: >> 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 <michael@walle.cc> >> --- >> drivers/nvmem/core.c | 16 ++++++++++++++++ >> include/linux/nvmem-consumer.h | 5 +++++ >> 2 files changed, 21 insertions(+) >> >> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c >> index 5357fc378700..cbfbe6264e6c 100644 >> --- a/drivers/nvmem/core.c >> +++ b/drivers/nvmem/core.c >> @@ -52,6 +52,7 @@ struct nvmem_cell_entry { >> int bytes; >> int bit_offset; >> int nbits; >> + nvmem_cell_post_process_t post_process; > > > two post_processing callbacks for cells is confusing tbh, we could > totally move to use of cell->post_process. > > one idea is to point cell->post_process to nvmem->cell_post_process > during cell creation time which should clean this up a bit. You'll then trigger the read-only check below for all the cells if nvmem->cell_post_process is set. > Other option is to move to using layouts for every thing. As mentioned in a previous reply, I can't see how it could be achieved. The problem here is that: (1) the layout isn't creating the cells, the OF parser is (2) even if we would create the cells, we wouldn't know which cell needs the post_process. So we are back to the situation above, were we have to add it to all the cells, making them read-only. [We depend on the name of the nvmem-consumer to apply the hook. > prefixing post_process with read should also make it explicit that > this callback is very specific to reads only. good idea. -michael >> struct device_node *np; >> struct nvmem_device *nvmem; >> struct list_head node; >> @@ -468,6 +469,7 @@ 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->post_process = info->post_process; >> cell->bit_offset = info->bit_offset; >> cell->nbits = info->nbits; >> @@ -1500,6 +1502,13 @@ 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->post_process) { >> + rc = cell->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); >> @@ -1608,6 +1617,13 @@ 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 post_process hook are read-only because we >> + * cannot reverse the operation and it might affect other cells, >> too. >> + */ >> + if (cell->post_process) >> + return -EINVAL; > > Post process was always implicitly for reads only, this check should > also tie the loose ends of cell_post_processing callback. > > > --srini >> + >> 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-consumer.h >> b/include/linux/nvmem-consumer.h >> index 980f9c9ac0bc..761b8ef78adc 100644 >> --- a/include/linux/nvmem-consumer.h >> +++ b/include/linux/nvmem-consumer.h >> @@ -19,6 +19,10 @@ struct device_node; >> struct nvmem_cell; >> struct nvmem_device; >> +/* duplicated from nvmem-provider.h */ >> +typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, >> int index, >> + unsigned int offset, void *buf, size_t bytes); >> + >> struct nvmem_cell_info { >> const char *name; >> unsigned int offset; >> @@ -26,6 +30,7 @@ struct nvmem_cell_info { >> unsigned int bit_offset; >> unsigned int nbits; >> struct device_node *np; >> + nvmem_cell_post_process_t post_process; >> }; >> /**
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 5357fc378700..cbfbe6264e6c 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -52,6 +52,7 @@ struct nvmem_cell_entry { int bytes; int bit_offset; int nbits; + nvmem_cell_post_process_t post_process; struct device_node *np; struct nvmem_device *nvmem; struct list_head node; @@ -468,6 +469,7 @@ 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->post_process = info->post_process; cell->bit_offset = info->bit_offset; cell->nbits = info->nbits; @@ -1500,6 +1502,13 @@ 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->post_process) { + rc = cell->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); @@ -1608,6 +1617,13 @@ 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 post_process hook are read-only because we + * cannot reverse the operation and it might affect other cells, too. + */ + if (cell->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-consumer.h b/include/linux/nvmem-consumer.h index 980f9c9ac0bc..761b8ef78adc 100644 --- a/include/linux/nvmem-consumer.h +++ b/include/linux/nvmem-consumer.h @@ -19,6 +19,10 @@ struct device_node; struct nvmem_cell; struct nvmem_device; +/* duplicated from nvmem-provider.h */ +typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, int index, + unsigned int offset, void *buf, size_t bytes); + struct nvmem_cell_info { const char *name; unsigned int offset; @@ -26,6 +30,7 @@ struct nvmem_cell_info { unsigned int bit_offset; unsigned int nbits; struct device_node *np; + nvmem_cell_post_process_t post_process; }; /**
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 <michael@walle.cc> --- drivers/nvmem/core.c | 16 ++++++++++++++++ include/linux/nvmem-consumer.h | 5 +++++ 2 files changed, 21 insertions(+)