kernel/linux.git/drivers/nvmem/core.c, branch v4.11.5

nvmem: core: Allow getting nvmem cell with a NULL cell id

2017-01-25T10:49:39+00:00

The nvmem cell with a NULL cell name/id should be the one with no accompanying 'nvmem-cell-names' property, and thus will be the cell at index 0 in the device tree. So, we default to index 0 and update the cell index only when nvmem cell name id exists. Suggested-by: Stephen Boyd Signed-off-by: Vivek Gautam Reviewed-by: Stephen Boyd Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Correct a bunch of function documentations

2017-01-25T10:49:39+00:00

Correct the documentation for arguments to a number of functions. Signed-off-by: Vivek Gautam Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Allow ignoring length when reading a cell

2017-01-25T10:49:39+00:00

nvmem_cell_read() API fills in the argument 'len' with the number of bytes read from the cell. Many users don't care about this length value. So allow users to pass a NULL pointer to this len field. Signed-off-by: Vivek Gautam Reviewed-by: Stephen Boyd Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: fix nvmem_cell_read() return type doc

2017-01-04T17:22:47+00:00

nvmem_cell_read() returns void *, not char *. This is a cleanup that got left out of commit a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently"). Signed-off-by: Brian Norris Fixes: a6c50912508d ("nvmem: Declare nvmem_cell_read() consistently") Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

remove lots of IS_ERR_VALUE abuses

2016-05-27T22:26:11+00:00

Most users of IS_ERR_VALUE() in the kernel are wrong, as they pass an 'int' into a function that takes an 'unsigned long' argument. This happens to work because the type is sign-extended on 64-bit architectures before it gets converted into an unsigned type. However, anything that passes an 'unsigned short' or 'unsigned int' argument into IS_ERR_VALUE() is guaranteed to be broken, as are 8-bit integers and types that are wider than 'unsigned long'. Andrzej Hajda has already fixed a lot of the worst abusers that were causing actual bugs, but it would be nice to prevent any users that are not passing 'unsigned long' arguments. This patch changes all users of IS_ERR_VALUE() that I could find on 32-bit ARM randconfig builds and x86 allmodconfig. For the moment, this doesn't change the definition of IS_ERR_VALUE() because there are probably still architecture specific users elsewhere. Almost all the warnings I got are for files that are better off using 'if (err)' or 'if (err < 0)'. The only legitimate user I could find that we get a warning for is the (32-bit only) freescale fman driver, so I did not remove the IS_ERR_VALUE() there but changed the type to 'unsigned long'. For 9pfs, I just worked around one user whose calling conventions are so obscure that I did not dare change the behavior. I was using this definition for testing: #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \ unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO)) which ends up making all 16-bit or wider types work correctly with the most plausible interpretation of what IS_ERR_VALUE() was supposed to return according to its users, but also causes a compile-time warning for any users that do not pass an 'unsigned long' argument. I suggested this approach earlier this year, but back then we ended up deciding to just fix the users that are obviously broken. After the initial warning that caused me to get involved in the discussion (fs/gfs2/dir.c) showed up again in the mainline kernel, Linus asked me to send the whole thing again. [ Updated the 9p parts as per Al Viro - Linus ] Signed-off-by: Arnd Bergmann Cc: Andrzej Hajda Cc: Andrew Morton Link: https://lkml.org/lkml/2016/1/7/363 Link: https://lkml.org/lkml/2016/5/27/486 Acked-by: Srinivas Kandagatla # For nvmem part Signed-off-by: Linus Torvalds

nvmem: core: remove regmap dependency

2016-05-01T21:01:00+00:00

nvmem uses regmap_raw_read/write apis to read/write data from providers, regmap raw apis stopped working with recent kernels which removed raw accessors on mmio bus. This resulted in broken nvmem for providers which are based on regmap mmio bus. This issue can be fixed temporarly by moving to other regmap apis, but we might hit same issue in future. Moving to interfaces based on read/write callbacks from providers would be more robust. This patch removes regmap dependency from nvmem and introduces read/write callbacks from the providers. Without this patch nvmem providers like qfprom based on regmap mmio bus would not work. Reported-by: Rajendra Nayak Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: Add backwards compatibility support for older EEPROM drivers.

2016-03-02T00:55:48+00:00

Older drivers made an 'eeprom' file available in the /sys device directory. Have the NVMEM core provide this to retain backwards compatibility. Signed-off-by: Andrew Lunn Acked-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: Add flag to export NVMEM to root only

2016-03-02T00:55:48+00:00

Legacy AT24, AT25 EEPROMs are exported in sys so that only root can read the contents. The EEPROMs may contain sensitive information. Add a flag so the provide can indicate that NVMEM should also restrict access to root only. Signed-off-by: Andrew Lunn Acked-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix error path in nvmem_add_cells()

2016-02-12T03:23:28+00:00

The current code fails to nvmem_cell_drop(cells[0]) - even worse, if the loop above fails already at i==0, we'll enter an essentially infinite loop doing nvmem_cell_drop on cells[-1], cells[-2], ... which is unlikely to end well. Also, we're not freeing the temporary backing array cells on the error path. Signed-off-by: Rasmus Villemoes Signed-off-by: Greg Kroah-Hartman

nvmem: core: return error for non word aligned access

2016-02-08T07:07:21+00:00

nvmem providers have restrictions on register strides, so return error when users attempt to read/write buffers with sizes which are less than word size. Without this patch the userspace would continue to try as it does not get any error from the nvmem core, resulting in a hang or endless loop in userspace. Reported-by: Ariel D'Alessandro Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman