| Message ID | 20210401193133.18129-5-p.yadav@ti.com |
|---|---|
| State | Superseded |
| Delegated to: | Jagannadha Sutradharudu Teki |
| Headers | show |
| Series | mtd: spi-nor-core: add xSPI Octal DTR support | expand |
On 4/1/21 3:31 PM, Pratyush Yadav wrote: > spi_mem_default_supports_op() rejects DTR ops by default to ensure that > the controller drivers that haven't been updated with DTR support > continue to reject them. It also makes sure that controllers that don't > support DTR mode at all (which is most of them at the moment) also > reject them. > > This means that controller drivers that want to support DTR mode can't > use spi_mem_default_supports_op(). Driver authors have to roll their own > supports_op() function and mimic the buswidth checks. See > spi-cadence-quadspi.c for example. Or even worse, driver authors might > skip it completely or get it wrong. > > Add spi_mem_dtr_supports_op(). It provides a basic sanity check for DTR > ops and performs the buswidth requirement check. Move the logic for > checking buswidth in spi_mem_default_supports_op() to a separate > function so the logic is not repeated twice. > > Signed-off-by: Pratyush Yadav <p.yadav@ti.com> > --- > drivers/spi/spi-mem.c | 22 +++++++++++++++++++--- > include/spi-mem.h | 2 ++ > 2 files changed, 21 insertions(+), 3 deletions(-) > > diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c > index 541cd0e5a7..be1737a2c6 100644 > --- a/drivers/spi/spi-mem.c > +++ b/drivers/spi/spi-mem.c > @@ -145,8 +145,8 @@ static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx) > return -ENOTSUPP; > } > > -bool spi_mem_default_supports_op(struct spi_slave *slave, > - const struct spi_mem_op *op) > +static bool spi_mem_check_buswidth(struct spi_slave *slave, > + const struct spi_mem_op *op) > { > if (spi_check_buswidth_req(slave, op->cmd.buswidth, true)) > return false; > @@ -164,13 +164,29 @@ bool spi_mem_default_supports_op(struct spi_slave *slave, > op->data.dir == SPI_MEM_DATA_OUT)) > return false; > > + return true; > +} > + > +bool spi_mem_dtr_supports_op(struct spi_slave *slave, > + const struct spi_mem_op *op) > +{ > + if (op->cmd.nbytes != 2) > + return false; Why does the command bytes need to be 2? --Sean > + > + return spi_mem_check_buswidth(slave, op); > +} > +EXPORT_SYMBOL_GPL(spi_mem_dtr_supports_op); > + > +bool spi_mem_default_supports_op(struct spi_slave *slave, > + const struct spi_mem_op *op) > +{ > if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr) > return false; > > if (op->cmd.nbytes != 1) > return false;> > - return true; > + return spi_mem_check_buswidth(slave, op); > } > EXPORT_SYMBOL_GPL(spi_mem_default_supports_op); > > diff --git a/include/spi-mem.h b/include/spi-mem.h > index dc53b517c1..37a9128c5b 100644 > --- a/include/spi-mem.h > +++ b/include/spi-mem.h > @@ -249,6 +249,8 @@ spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, > int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op); > > bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op); > +bool spi_mem_dtr_supports_op(struct spi_slave *slave, > + const struct spi_mem_op *op); > > bool spi_mem_default_supports_op(struct spi_slave *slave, > const struct spi_mem_op *op); >
On 02/04/21 06:31PM, Sean Anderson wrote: > On 4/1/21 3:31 PM, Pratyush Yadav wrote: > > spi_mem_default_supports_op() rejects DTR ops by default to ensure that > > the controller drivers that haven't been updated with DTR support > > continue to reject them. It also makes sure that controllers that don't > > support DTR mode at all (which is most of them at the moment) also > > reject them. > > > > This means that controller drivers that want to support DTR mode can't > > use spi_mem_default_supports_op(). Driver authors have to roll their own > > supports_op() function and mimic the buswidth checks. See > > spi-cadence-quadspi.c for example. Or even worse, driver authors might > > skip it completely or get it wrong. > > > > Add spi_mem_dtr_supports_op(). It provides a basic sanity check for DTR > > ops and performs the buswidth requirement check. Move the logic for > > checking buswidth in spi_mem_default_supports_op() to a separate > > function so the logic is not repeated twice. > > > > Signed-off-by: Pratyush Yadav <p.yadav@ti.com> > > --- > > drivers/spi/spi-mem.c | 22 +++++++++++++++++++--- > > include/spi-mem.h | 2 ++ > > 2 files changed, 21 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c > > index 541cd0e5a7..be1737a2c6 100644 > > --- a/drivers/spi/spi-mem.c > > +++ b/drivers/spi/spi-mem.c > > @@ -145,8 +145,8 @@ static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx) > > return -ENOTSUPP; > > } > > -bool spi_mem_default_supports_op(struct spi_slave *slave, > > - const struct spi_mem_op *op) > > +static bool spi_mem_check_buswidth(struct spi_slave *slave, > > + const struct spi_mem_op *op) > > { > > if (spi_check_buswidth_req(slave, op->cmd.buswidth, true)) > > return false; > > @@ -164,13 +164,29 @@ bool spi_mem_default_supports_op(struct spi_slave *slave, > > op->data.dir == SPI_MEM_DATA_OUT)) > > return false; > > + return true; > > +} > > + > > +bool spi_mem_dtr_supports_op(struct spi_slave *slave, > > + const struct spi_mem_op *op) > > +{ > > + if (op->cmd.nbytes != 2) > > + return false; > > Why does the command bytes need to be 2? They need to be 2 if the command buswidth is 8 because otherwise the command phase will only take up half a cycle. This should have been if (op->cmd.buswidth == 8 && op->cmd.nbytes != 2). > > --Sean > > > + > > + return spi_mem_check_buswidth(slave, op); > > +} > > +EXPORT_SYMBOL_GPL(spi_mem_dtr_supports_op); > > + > > +bool spi_mem_default_supports_op(struct spi_slave *slave, > > + const struct spi_mem_op *op) > > +{ > > if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr) > > return false; > > if (op->cmd.nbytes != 1) > > return false;> - return true; > > + return spi_mem_check_buswidth(slave, op); > > } > > EXPORT_SYMBOL_GPL(spi_mem_default_supports_op); > > diff --git a/include/spi-mem.h b/include/spi-mem.h > > index dc53b517c1..37a9128c5b 100644 > > --- a/include/spi-mem.h > > +++ b/include/spi-mem.h > > @@ -249,6 +249,8 @@ spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, > > int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op); > > bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op); > > +bool spi_mem_dtr_supports_op(struct spi_slave *slave, > > + const struct spi_mem_op *op); > > bool spi_mem_default_supports_op(struct spi_slave *slave, > > const struct spi_mem_op *op); > > >
On 4/5/21 3:40 AM, Pratyush Yadav wrote: > On 02/04/21 06:31PM, Sean Anderson wrote: >> On 4/1/21 3:31 PM, Pratyush Yadav wrote: >>> spi_mem_default_supports_op() rejects DTR ops by default to ensure that >>> the controller drivers that haven't been updated with DTR support >>> continue to reject them. It also makes sure that controllers that don't >>> support DTR mode at all (which is most of them at the moment) also >>> reject them. >>> >>> This means that controller drivers that want to support DTR mode can't >>> use spi_mem_default_supports_op(). Driver authors have to roll their own >>> supports_op() function and mimic the buswidth checks. See >>> spi-cadence-quadspi.c for example. Or even worse, driver authors might >>> skip it completely or get it wrong. >>> >>> Add spi_mem_dtr_supports_op(). It provides a basic sanity check for DTR >>> ops and performs the buswidth requirement check. Move the logic for >>> checking buswidth in spi_mem_default_supports_op() to a separate >>> function so the logic is not repeated twice. >>> >>> Signed-off-by: Pratyush Yadav <p.yadav@ti.com> >>> --- >>> drivers/spi/spi-mem.c | 22 +++++++++++++++++++--- >>> include/spi-mem.h | 2 ++ >>> 2 files changed, 21 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c >>> index 541cd0e5a7..be1737a2c6 100644 >>> --- a/drivers/spi/spi-mem.c >>> +++ b/drivers/spi/spi-mem.c >>> @@ -145,8 +145,8 @@ static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx) >>> return -ENOTSUPP; >>> } >>> -bool spi_mem_default_supports_op(struct spi_slave *slave, >>> - const struct spi_mem_op *op) >>> +static bool spi_mem_check_buswidth(struct spi_slave *slave, >>> + const struct spi_mem_op *op) >>> { >>> if (spi_check_buswidth_req(slave, op->cmd.buswidth, true)) >>> return false; >>> @@ -164,13 +164,29 @@ bool spi_mem_default_supports_op(struct spi_slave *slave, >>> op->data.dir == SPI_MEM_DATA_OUT)) >>> return false; >>> + return true; >>> +} >>> + >>> +bool spi_mem_dtr_supports_op(struct spi_slave *slave, >>> + const struct spi_mem_op *op) >>> +{ >>> + if (op->cmd.nbytes != 2) >>> + return false; >> >> Why does the command bytes need to be 2? > > They need to be 2 if the command buswidth is 8 because otherwise the > command phase will only take up half a cycle. This should have been if > (op->cmd.buswidth == 8 && op->cmd.nbytes != 2). Perhaps the most correct then is int width = cmd.dtr ? cmd.buswidth * 2 : cmd.buswidth; if (cmd.nbytes % width) { ... } >> >> --Sean >> >>> + >>> + return spi_mem_check_buswidth(slave, op); >>> +} >>> +EXPORT_SYMBOL_GPL(spi_mem_dtr_supports_op); >>> + >>> +bool spi_mem_default_supports_op(struct spi_slave *slave, >>> + const struct spi_mem_op *op) >>> +{ >>> if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr) >>> return false; >>> if (op->cmd.nbytes != 1) >>> return false;> - return true; >>> + return spi_mem_check_buswidth(slave, op); >>> } >>> EXPORT_SYMBOL_GPL(spi_mem_default_supports_op); >>> diff --git a/include/spi-mem.h b/include/spi-mem.h >>> index dc53b517c1..37a9128c5b 100644 >>> --- a/include/spi-mem.h >>> +++ b/include/spi-mem.h >>> @@ -249,6 +249,8 @@ spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, >>> int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op); >>> bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op); >>> +bool spi_mem_dtr_supports_op(struct spi_slave *slave, >>> + const struct spi_mem_op *op); >>> bool spi_mem_default_supports_op(struct spi_slave *slave, >>> const struct spi_mem_op *op); >>> >> >
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 541cd0e5a7..be1737a2c6 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -145,8 +145,8 @@ static int spi_check_buswidth_req(struct spi_slave *slave, u8 buswidth, bool tx) return -ENOTSUPP; } -bool spi_mem_default_supports_op(struct spi_slave *slave, - const struct spi_mem_op *op) +static bool spi_mem_check_buswidth(struct spi_slave *slave, + const struct spi_mem_op *op) { if (spi_check_buswidth_req(slave, op->cmd.buswidth, true)) return false; @@ -164,13 +164,29 @@ bool spi_mem_default_supports_op(struct spi_slave *slave, op->data.dir == SPI_MEM_DATA_OUT)) return false; + return true; +} + +bool spi_mem_dtr_supports_op(struct spi_slave *slave, + const struct spi_mem_op *op) +{ + if (op->cmd.nbytes != 2) + return false; + + return spi_mem_check_buswidth(slave, op); +} +EXPORT_SYMBOL_GPL(spi_mem_dtr_supports_op); + +bool spi_mem_default_supports_op(struct spi_slave *slave, + const struct spi_mem_op *op) +{ if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr) return false; if (op->cmd.nbytes != 1) return false; - return true; + return spi_mem_check_buswidth(slave, op); } EXPORT_SYMBOL_GPL(spi_mem_default_supports_op); diff --git a/include/spi-mem.h b/include/spi-mem.h index dc53b517c1..37a9128c5b 100644 --- a/include/spi-mem.h +++ b/include/spi-mem.h @@ -249,6 +249,8 @@ spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, int spi_mem_adjust_op_size(struct spi_slave *slave, struct spi_mem_op *op); bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op); +bool spi_mem_dtr_supports_op(struct spi_slave *slave, + const struct spi_mem_op *op); bool spi_mem_default_supports_op(struct spi_slave *slave, const struct spi_mem_op *op);
spi_mem_default_supports_op() rejects DTR ops by default to ensure that the controller drivers that haven't been updated with DTR support continue to reject them. It also makes sure that controllers that don't support DTR mode at all (which is most of them at the moment) also reject them. This means that controller drivers that want to support DTR mode can't use spi_mem_default_supports_op(). Driver authors have to roll their own supports_op() function and mimic the buswidth checks. See spi-cadence-quadspi.c for example. Or even worse, driver authors might skip it completely or get it wrong. Add spi_mem_dtr_supports_op(). It provides a basic sanity check for DTR ops and performs the buswidth requirement check. Move the logic for checking buswidth in spi_mem_default_supports_op() to a separate function so the logic is not repeated twice. Signed-off-by: Pratyush Yadav <p.yadav@ti.com> --- drivers/spi/spi-mem.c | 22 +++++++++++++++++++--- include/spi-mem.h | 2 ++ 2 files changed, 21 insertions(+), 3 deletions(-)