| Message ID | 20200206084443.209719-1-gch981213@gmail.com |
|---|---|
| Headers | show |
| Series | spi: add driver for ar934x spi controller | expand |
On Thu, Feb 06, 2020 at 04:44:42PM +0800, Chuanhong Guo wrote: This looks good, just a couple of comments below: > --- /dev/null > +++ b/drivers/spi/spi-ar934x.c > @@ -0,0 +1,230 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * SPI controller driver for Qualcomm Atheros AR934x/QCA95xx SoCs Please make the entire comment block a C++ one so things look more intentional. > +static int ar934x_spi_transfer_one(struct spi_controller *master, > + struct spi_message *m) > +{ > + struct ar934x_spi *sp = spi_controller_get_devdata(master); > + struct spi_transfer *t = NULL; ... > + > + m->actual_length = 0; > + list_for_each_entry(t, &m->transfers, transfer_list) { It looks like this could just be a transfer_one() operation instead of transfer_one_message() (which is what this is in spite of the name)? There's nothing custom outside this loop that I can see.
On Thu, Feb 6, 2020 at 7:31 PM Mark Brown <broonie@kernel.org> wrote: > > On Thu, Feb 06, 2020 at 04:44:42PM +0800, Chuanhong Guo wrote: > > This looks good, just a couple of comments below: > > > --- /dev/null > > +++ b/drivers/spi/spi-ar934x.c > > @@ -0,0 +1,230 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * SPI controller driver for Qualcomm Atheros AR934x/QCA95xx SoCs > > Please make the entire comment block a C++ one so things look > more intentional. Got it. I'll do this in v2. > > > +static int ar934x_spi_transfer_one(struct spi_controller *master, > > + struct spi_message *m) > > +{ > > + struct ar934x_spi *sp = spi_controller_get_devdata(master); > > + struct spi_transfer *t = NULL; > > ... > > > + > > + m->actual_length = 0; > > + list_for_each_entry(t, &m->transfers, transfer_list) { > > It looks like this could just be a transfer_one() operation > instead of transfer_one_message() (which is what this is in spite > of the name)? There's nothing custom outside this loop that I > can see. Chipselect is also handled during transfer. Controller asserts corresponding chipselect in SHIFT_CTRL register, and if SHIFT_TERM bit is set, controller will deassert chipselect after current transfer is done. I need to know whether this is the last transfer and set SHIFT_TERM accordingly. Regards, Chuanhong Guo
On Thu, Feb 6, 2020 at 8:30 PM Chuanhong Guo <gch981213@gmail.com> wrote: > > It looks like this could just be a transfer_one() operation > > instead of transfer_one_message() (which is what this is in spite > > of the name)? There's nothing custom outside this loop that I > > can see. > > Chipselect is also handled during transfer. Controller asserts > corresponding chipselect in SHIFT_CTRL register, and if SHIFT_TERM bit > is set, controller will deassert chipselect after current transfer is > done. I need to know whether this is the last transfer and set > SHIFT_TERM accordingly. Oh, I remembered that I saw transfer_one function name somewhere and thought maybe I could shorten the function name a bit. I'll correct this back to ar934x_spi_transfer_one_message in v2. Regards, Chuanhong Guo
On Thu, Feb 06, 2020 at 08:33:33PM +0800, Chuanhong Guo wrote: > On Thu, Feb 6, 2020 at 8:30 PM Chuanhong Guo <gch981213@gmail.com> wrote: > > Chipselect is also handled during transfer. Controller asserts > > corresponding chipselect in SHIFT_CTRL register, and if SHIFT_TERM bit > > is set, controller will deassert chipselect after current transfer is > > done. I need to know whether this is the last transfer and set > > SHIFT_TERM accordingly. > Oh, I remembered that I saw transfer_one function name somewhere and > thought maybe I could shorten the function name a bit. I'll correct > this back to ar934x_spi_transfer_one_message in v2. OK, sounds good - I see the chip select handling now.