Hi Pratyush On 4/26/21 6:26 PM, Pratyush Yadav wrote: > Hi, > > On 26/04/21 04:39PM, patrice.chotard@xxxxxxxxxxx wrote: >> From: Christophe Kerello <christophe.kerello@xxxxxxxxxxx> >> >> With STM32 QSPI, it is possible to poll the status register of the device. >> This could be done to offload the CPU during an operation (erase or >> program a SPI NAND for example). >> >> spi_mem_poll_status API has been added to handle this feature. >> >> Signed-off-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx> >> Signed-off-by: Patrice Chotard <patrice.chotard@xxxxxxxxxxx> >> --- >> drivers/spi/spi-mem.c | 34 ++++++++++++++++++++++++++++++++++ >> include/linux/spi/spi-mem.h | 8 ++++++++ >> 2 files changed, 42 insertions(+) >> >> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c >> index 1513553e4080..43dce4b0efa4 100644 >> --- a/drivers/spi/spi-mem.c >> +++ b/drivers/spi/spi-mem.c >> @@ -743,6 +743,40 @@ static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv) >> return container_of(drv, struct spi_mem_driver, spidrv.driver); >> } >> >> +/** >> + * spi_mem_poll_status() - Poll memory device status >> + * @mem: SPI memory device >> + * @op: the memory operation to execute >> + * @mask: status bitmask to ckeck >> + * @match: status expected value > > Technically, (status & mask) expected value. Dunno if that is obvious > enough to not spell out explicitly. Yes, match = (status & mask) I will update the comment accordingly. > >> + * @timeout: timeout >> + * >> + * This function send a polling status request to the controller driver >> + * >> + * Return: 0 in case of success, -ETIMEDOUT in case of error, >> + * -EOPNOTSUPP if not supported. >> + */ >> +int spi_mem_poll_status(struct spi_mem *mem, >> + const struct spi_mem_op *op, >> + u8 mask, u8 match, u16 timeout) >> +{ >> + struct spi_controller *ctlr = mem->spi->controller; >> + int ret = -EOPNOTSUPP; >> + >> + if (ctlr->mem_ops && ctlr->mem_ops->poll_status) { > > You should call spi_mem_supports_op() before sending any ops to the > controller. Invalid/unsupported ops can cause unexpected behavior. Ok i will add it. Thanks Patrice > >> + ret = spi_mem_access_start(mem); >> + if (ret) >> + return ret; >> + >> + ret = ctlr->mem_ops->poll_status(mem, op, mask, match, timeout); > > I wonder if it is better to let spi-mem core take care of the timeout > part. On one hand it reduces code duplication on the driver side a > little bit. Plus it makes sure drivers don't mess anything up with bad > (or no) handling of the timeout. But on the other hand the interface > becomes a bit awkward since you'd have to pass a struct completion > around, and it isn't something particularly hard to get right either. > What do you think? > >> + >> + spi_mem_access_end(mem); >> + } >> + >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(spi_mem_poll_status); >> + >> static int spi_mem_probe(struct spi_device *spi) >> { >> struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver); >> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h >> index 2b65c9edc34e..5f78917c0f68 100644 >> --- a/include/linux/spi/spi-mem.h >> +++ b/include/linux/spi/spi-mem.h >> @@ -250,6 +250,7 @@ static inline void *spi_mem_get_drvdata(struct spi_mem *mem) >> * the currently mapped area), and the caller of >> * spi_mem_dirmap_write() is responsible for calling it again in >> * this case. >> + * @poll_status: poll memory device status >> * >> * This interface should be implemented by SPI controllers providing an >> * high-level interface to execute SPI memory operation, which is usually the >> @@ -274,6 +275,9 @@ struct spi_controller_mem_ops { >> u64 offs, size_t len, void *buf); >> ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc, >> u64 offs, size_t len, const void *buf); >> + int (*poll_status)(struct spi_mem *mem, >> + const struct spi_mem_op *op, >> + u8 mask, u8 match, u16 timeout); >> }; >> >> /** >> @@ -369,6 +373,10 @@ devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem, >> void devm_spi_mem_dirmap_destroy(struct device *dev, >> struct spi_mem_dirmap_desc *desc); >> >> +int spi_mem_poll_status(struct spi_mem *mem, >> + const struct spi_mem_op *op, >> + u8 mask, u8 match, u16 timeout); >> + >> int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv, >> struct module *owner); >