kernel/linux.git/drivers/nvmem/core.c, branch v5.2.16

nvmem: core: add NVMEM_SYSFS Kconfig

2019-04-25T17:44:33+00:00

Many nvmem providers are not very keen on having default sysfs nvmem entry, as most of the usecases for them are inside kernel itself. And in some cases read/writes to some areas in nvmem are restricted and trapped at secure monitor level, so accessing them from userspace would result in board reboots. This patch adds new NVMEM_SYSFS Kconfig to make binary sysfs entry an optional one. This provision will give more flexibility to users. This patch also moves existing sysfs code to a new file so that its not compiled in when its not really required. Signed-off-by: Srinivas Kandagatla Reviewed-by: Mika Westerberg Reviewed-by: Gaurav Kohli Tested-by: Gaurav Kohli Signed-off-by: Greg Kroah-Hartman

nvmem: core: fix read buffer in place

2019-04-25T17:43:12+00:00

When the bit_offset in the cell is zero, the pointer to the msb will not be properly initialized (ie, will still be pointing to the first byte in the buffer). This being the case, if there are bits to clear in the msb, those will be left untouched while the mask will incorrectly clear bit positions on the first byte. This commit also makes sure that any byte unused in the cell is cleared. Signed-off-by: Jorge Ramirez-Ortiz Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: add nvmem_cell_read_u16

2019-04-25T17:43:12+00:00

Add nvmem_cell_read_u16() helper to ease read of an u16 value on consumer side. This is inspired by nvmem_cell_read_u32() function. This helper is useful on stm32 that has 16 bits data cells stored in non volatile memory. Signed-off-by: Fabrice Gasnier Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: don't check the return value of notifier chain call

2019-02-19T13:50:11+00:00

blocking_notifier_call_chain() returns the value returned by the last registered callback. A positive return value doesn't indicate an error and an nvmem device should correctly register irrespective of any notifier callback failures. Drop the retval check. Fixes: bee1138bea15 ("nvmem: add a notifier chain") Cc: stable@vger.kernel.org Signed-off-by: Bartosz Golaszewski Acked-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Avoid useless iterations in nvmem_cell_get_from_lookup()

2019-01-31T15:24:15+00:00

Once the correct cell has been found there is no need to continue iterating, just stop there. While at it replace the goto used to leave the loop with simple break statements. Signed-off-by: Alban Bedel Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Fix device reference leak

2019-01-31T15:24:15+00:00

__nvmem_device_get() make use of bus_find_device() to get the relevant device and this function increase the reference count of the device found, however this is not accounted for anywhere. Fix __nvmem_device_get() and __nvmem_device_put() to properly release this reference count. Signed-off-by: Alban Bedel Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Always reference the device returned by nvmem_device_get()

2019-01-31T15:24:14+00:00

In nvmem_device_get(), when the device lookup fails with DT it currently fallback on nvmem_find() which is wrong for two reasons. First nvmem_find() return NULL when nothing is found instead of an ERR_PTR. But nvmem_find() also just lookup the device, it doesn't reference the module and increment the reference count like it is done in the DT path. To fix this we replace the call to nvmem_find() with a call to __nvmem_device_get() which does all the referencing and return a proper ERR_PTR in case of error. Signed-off-by: Alban Bedel Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Properly handle connection ID in of_nvmem_device_get()

2019-01-31T15:24:14+00:00

of_nvmem_device_get() would crash if NULL was passed as a connection ID. Rework this to use the usual sementic of assuming the first connection when no connection ID is given. Furthermore of_nvmem_device_get() would return -EINVAL when it failed to resolve the connection, making it impossible to properly implement an optional connection. Return -ENOENT instead to let the caller know that the connection doesn't exists. Signed-off-by: Alban Bedel Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Fix cell lookup when no cell is found

2019-01-31T15:24:14+00:00

If the cell list is not empty and nvmem_find_cell_by_node/name() is called for a cell that is not present in the list they will return an invalid pointer instead of NULL. This happen because list_for_each_entry() stop once it reach the list head again, but as the list head is not contained in a struct nvmem_cell the iteration variable then contains an invalid value. This is easily solved by using a variable to iterate over the list and one to return the cell found. Signed-off-by: Alban Bedel Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman

nvmem: core: Fix of_nvmem_cell_get() for optional cells

2019-01-31T15:24:14+00:00

of_nvmem_cell_get() should return -ENOENT when a cell isn't defined, otherwise callers can't distinguish between a missing cell and other errors. Signed-off-by: Alban Bedel Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman