2013-06-28 18:44:39

by Hartley Sweeten

Subject: [PATCH 4/8] spi: spi-ep93xx: remove bits_per_word() helper

This inline helper function is only used to determine the bus width
of the current transfer (8 or 16 bit). Add a bool flag to the private
structure and set it appropriately for each transfer.

Signed-off-by: H Hartley Sweeten <[email protected]>
Cc: Ryan Mallon <[email protected]>
Cc: Mika Westerberg <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Grant Likely <[email protected]>
---
drivers/spi/spi-ep93xx.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
index bcfd35a..4fab3bb 100644
--- a/drivers/spi/spi-ep93xx.c
+++ b/drivers/spi/spi-ep93xx.c
@@ -116,6 +116,7 @@ struct ep93xx_spi {
unsigned long min_rate;
unsigned long max_rate;
bool running;
+ bool word_xfer;
struct workqueue_struct *wq;
struct work_struct msg_work;
struct completion wait;
@@ -407,17 +408,9 @@ static void ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
writew(cr0, espi->regs_base + SSPCR0);
}

-static inline int bits_per_word(const struct ep93xx_spi *espi)
-{
- struct spi_message *msg = espi->current_msg;
- struct spi_transfer *t = msg->state;
-
- return t->bits_per_word;
-}
-
static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
{
- if (bits_per_word(espi) > 8) {
+ if (espi->word_xfer) {
u16 tx_val = 0;

if (t->tx_buf)
@@ -436,7 +429,7 @@ static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)

static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
{
- if (bits_per_word(espi) > 8) {
+ if (espi->word_xfer) {
u16 rx_val;

rx_val = readw(espi->regs_base + SSPDR);
@@ -522,7 +515,7 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
size_t len = t->len;
int i, ret, nents;

- if (bits_per_word(espi) > 8)
+ if (espi->word_xfer)
buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
else
buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
@@ -699,6 +692,7 @@ static void ep93xx_spi_process_transfer(struct ep93xx_spi *espi,

ep93xx_spi_chip_setup(espi, chip);

+ espi->word_xfer = (t->bits_per_word > 8) ? true : false;
espi->rx = 0;
espi->tx = 0;

--
1.8.1.4

2013-06-28 23:22:17

by Ryan Mallon

Subject: Re: [PATCH 4/8] spi: spi-ep93xx: remove bits_per_word() helper

On 29/06/13 04:44, H Hartley Sweeten wrote:

> This inline helper function is only used to determine the bus width
> of the current transfer (8 or 16 bit). Add a bool flag to the private
> structure and set it appropriately for each transfer.
>
> Signed-off-by: H Hartley Sweeten <[email protected]>
> Cc: Ryan Mallon <[email protected]>
> Cc: Mika Westerberg <[email protected]>
> Cc: Mark Brown <[email protected]>
> Cc: Grant Likely <[email protected]>
> ---
> drivers/spi/spi-ep93xx.c | 16 +++++-----------
> 1 file changed, 5 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
> index bcfd35a..4fab3bb 100644
> --- a/drivers/spi/spi-ep93xx.c
> +++ b/drivers/spi/spi-ep93xx.c
> @@ -116,6 +116,7 @@ struct ep93xx_spi {
> unsigned long min_rate;
> unsigned long max_rate;
> bool running;
> + bool word_xfer;


I think this is a slightly confusing name. Maybe something like
is_16bit_xfer would be better?

> struct workqueue_struct *wq;
> struct work_struct msg_work;
> struct completion wait;
> @@ -407,17 +408,9 @@ static void ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
> writew(cr0, espi->regs_base + SSPCR0);
> }
>
> -static inline int bits_per_word(const struct ep93xx_spi *espi)
> -{
> - struct spi_message *msg = espi->current_msg;
> - struct spi_transfer *t = msg->state;
> -
> - return t->bits_per_word;
> -}
> -
> static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
> {
> - if (bits_per_word(espi) > 8) {
> + if (espi->word_xfer) {
> u16 tx_val = 0;
>
> if (t->tx_buf)
> @@ -436,7 +429,7 @@ static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
>
> static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
> {
> - if (bits_per_word(espi) > 8) {
> + if (espi->word_xfer) {
> u16 rx_val;
>
> rx_val = readw(espi->regs_base + SSPDR);
> @@ -522,7 +515,7 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
> size_t len = t->len;
> int i, ret, nents;
>
> - if (bits_per_word(espi) > 8)
> + if (espi->word_xfer)
> buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
> else
> buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
> @@ -699,6 +692,7 @@ static void ep93xx_spi_process_transfer(struct ep93xx_spi *espi,
>
> ep93xx_spi_chip_setup(espi, chip);
>
> + espi->word_xfer = (t->bits_per_word > 8) ? true : false;


espi->word_xfer = (t->bits_per_word > 8);

This patch is fine, but not sure it is entirely worth it. The
information is already stored in t->bits_per_word and the cost
of retrieving it is pretty minimal.

~Ryan

2013-06-30 16:18:45

by Mika Westerberg

Subject: Re: [PATCH 4/8] spi: spi-ep93xx: remove bits_per_word() helper

On Sat, Jun 29, 2013 at 09:21:48AM +1000, Ryan Mallon wrote:
> On 29/06/13 04:44, H Hartley Sweeten wrote:
>
> > This inline helper function is only used to determine the bus width
> > of the current transfer (8 or 16 bit). Add a bool flag to the private
> > structure and set it appropriately for each transfer.
> >
> > Signed-off-by: H Hartley Sweeten <[email protected]>
> > Cc: Ryan Mallon <[email protected]>
> > Cc: Mika Westerberg <[email protected]>
> > Cc: Mark Brown <[email protected]>
> > Cc: Grant Likely <[email protected]>
> > ---
> > drivers/spi/spi-ep93xx.c | 16 +++++-----------
> > 1 file changed, 5 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
> > index bcfd35a..4fab3bb 100644
> > --- a/drivers/spi/spi-ep93xx.c
> > +++ b/drivers/spi/spi-ep93xx.c
> > @@ -116,6 +116,7 @@ struct ep93xx_spi {
> > unsigned long min_rate;
> > unsigned long max_rate;
> > bool running;
> > + bool word_xfer;
>
>
> I think this is a slightly confusing name. Maybe something like
> is_16bit_xfer would be better?
>
> > struct workqueue_struct *wq;
> > struct work_struct msg_work;
> > struct completion wait;
> > @@ -407,17 +408,9 @@ static void ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
> > writew(cr0, espi->regs_base + SSPCR0);
> > }
> >
> > -static inline int bits_per_word(const struct ep93xx_spi *espi)
> > -{
> > - struct spi_message *msg = espi->current_msg;
> > - struct spi_transfer *t = msg->state;
> > -
> > - return t->bits_per_word;
> > -}
> > -
> > static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
> > {
> > - if (bits_per_word(espi) > 8) {
> > + if (espi->word_xfer) {
> > u16 tx_val = 0;
> >
> > if (t->tx_buf)
> > @@ -436,7 +429,7 @@ static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
> >
> > static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
> > {
> > - if (bits_per_word(espi) > 8) {
> > + if (espi->word_xfer) {
> > u16 rx_val;
> >
> > rx_val = readw(espi->regs_base + SSPDR);
> > @@ -522,7 +515,7 @@ ep93xx_spi_dma_prepare(struct ep93xx_spi *espi, enum dma_transfer_direction dir)
> > size_t len = t->len;
> > int i, ret, nents;
> >
> > - if (bits_per_word(espi) > 8)
> > + if (espi->word_xfer)
> > buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
> > else
> > buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > @@ -699,6 +692,7 @@ static void ep93xx_spi_process_transfer(struct ep93xx_spi *espi,
> >
> > ep93xx_spi_chip_setup(espi, chip);
> >
> > + espi->word_xfer = (t->bits_per_word > 8) ? true : false;
>
>
> espi->word_xfer = (t->bits_per_word > 8);

Or even
espi->word_xfer = t->bits_per_word > 8;

> This patch is fine, but not sure it is entirely worth it. The
> information is already stored in t->bits_per_word and the cost
> of retrieving it is pretty minimal.

I agree.