Hi Frieder, On Thu, 5 Jul 2018 13:14:57 +0200 Frieder Schrempf <[email protected]> wrote:
> When porting (Q)SPI controller drivers from the MTD layer to the SPI > layer, the naming scheme for the memory devices changes. To be able > to keep compatibility with the old drivers naming scheme, a function > is added to the SPI mem interface to let controller drivers set a > custom name for the memory. > > Example for the FSL QSPI driver: > > Name with the old driver: 21e0000.qspi, > or with multiple devices: 21e0000.qspi-0, 21e0000.qspi-1, ... > > Name with the new driver without spi_mem_get_name: spi4.0 > > Signed-off-by: Frieder Schrempf <[email protected]> > --- > Changes in v2: > ============== > * Add a name field to struct spi_mem and fill it while probing > > drivers/spi/spi-mem.c | 30 ++++++++++++++++++++++++++++++ > include/linux/spi/spi-mem.h | 7 ++++++- > 2 files changed, 36 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c > index 990770d..048101c 100644 > --- a/drivers/spi/spi-mem.c > +++ b/drivers/spi/spi-mem.c > @@ -311,6 +311,26 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct > spi_mem_op *op) > EXPORT_SYMBOL_GPL(spi_mem_exec_op); > > /** > + * spi_mem_get_name() - Let drivers using the SPI mem interface specify a > + * custom name for the memory to avoid compatibility > + * issues with ported drivers. You're not describing what this function does, but why it was introduced. Not sure the spi-mem user/driver cares about that, these are just internal details. Probably something you should put in the ->get_name() hook doc. > + * @mem: the SPI memory > + * > + * When porting (Q)SPI controller drivers from the MTD layer to the SPI > + * layer, the naming scheme for the memory devices changes. To be able to > + * keep compatibility with the old drivers naming scheme, this function can > + * be used to get a custom name from the controller driver. > + * If no custom name is available, the name of the SPI device is returned. Ditto. Just say that this function returns the spi-mem device name which can be used by the upper layer if they need to expose a user-friendly name. > + * > + * Return: a char array that contains the name for the flash memory ^ a string? Return: a string containing the name of the memory device to be used by the spi-mem user > + */ > +const char *spi_mem_get_name(struct spi_mem *mem) > +{ > + return mem->name; > +} > +EXPORT_SYMBOL_GPL(spi_mem_get_name); > + > +/** > * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to > * match controller limitations > * @mem: the SPI memory > @@ -344,6 +364,7 @@ static inline struct spi_mem_driver > *to_spi_mem_drv(struct device_driver *drv) > static int spi_mem_probe(struct spi_device *spi) > { > struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver); > + struct spi_controller *ctlr = spi->controller; > struct spi_mem *mem; > > mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL); > @@ -351,6 +372,15 @@ static int spi_mem_probe(struct spi_device *spi) > return -ENOMEM; > > mem->spi = spi; > + > + if (ctlr->mem_ops && ctlr->mem_ops->get_name) > + mem->name = ctlr->mem_ops->get_name(mem); > + else > + mem->name = dev_name(&spi->dev); > + > + if (IS_ERR_OR_NULL(mem->name)) > + return PTR_ERR(mem->name); > + > spi_set_drvdata(spi, mem); > > return memdrv->probe(mem); > diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h > index 4fa34a2..c3f82d1 100644 > --- a/include/linux/spi/spi-mem.h > +++ b/include/linux/spi/spi-mem.h > @@ -124,7 +124,8 @@ struct spi_mem_op { > /** > * struct spi_mem - describes a SPI memory device > * @spi: the underlying SPI device > - * @drvpriv: spi_mem_drviver private data > + * @drvpriv: spi_mem_driver private data Can you fix this typo in a separate patch? > + * @name: name of the SPI memory device > * > * Extra information that describe the SPI memory device and may be needed by > * the controller to properly handle this device should be placed here. > @@ -135,6 +136,7 @@ struct spi_mem_op { > struct spi_mem { > struct spi_device *spi; > void *drvpriv; > + char *name; > }; > > /** > @@ -178,6 +180,7 @@ struct spi_controller_mem_ops { > const struct spi_mem_op *op); > int (*exec_op)(struct spi_mem *mem, > const struct spi_mem_op *op); > + const char *(*get_name)(struct spi_mem *mem); You forgot to document this hook. Also, it's important to mention that if the name returned by this function is dynamically allocated, it should be allocated with devm_xxxx(), because we don't have a ->free_name() function. > }; > > /** > @@ -236,6 +239,8 @@ bool spi_mem_supports_op(struct spi_mem *mem, > int spi_mem_exec_op(struct spi_mem *mem, > const struct spi_mem_op *op); > > +const char *spi_mem_get_name(struct spi_mem *mem); > + > int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv, > struct module *owner); > Thanks, Boris
