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Subject[PATCH 4/5] spi: sh-msiof: Refactor sh_msiof_transfer_one()
Date

- Move buffer pointer and length setup to the top,
- Make unsigned values unsigned,
- Loop over words and increment pointers instead of recalculating them,
which allows to kill bytes_done.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
drivers/spi/spi-sh-msiof.c | 43 +++++++++++++++++++++----------------------
1 file changed, 21 insertions(+), 22 deletions(-)

diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c
index 29dee0436a9a..ef831f1c1803 100644
--- a/drivers/spi/spi-sh-msiof.c
+++ b/drivers/spi/spi-sh-msiof.c
@@ -616,16 +616,17 @@ static int sh_msiof_transfer_one(struct spi_master *master,
struct sh_msiof_spi_priv *p = spi_master_get_devdata(master);
void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int);
void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int);
- int bits;
- int bytes_per_word;
- int bytes_done;
- int words;
+ const void *tx_buf = t->tx_buf;
+ void *rx_buf = t->rx_buf;
+ unsigned int len = t->len;
+ unsigned int bits = t->bits_per_word;
+ unsigned int bytes_per_word;
+ unsigned int words;
int n;
bool swab;

- bits = t->bits_per_word;

- if (bits <= 8 && t->len > 15 && !(t->len & 3)) {
+ if (bits <= 8 && len > 15 && !(len & 3)) {
bits = 32;
swab = true;
} else {
@@ -639,34 +640,34 @@ static int sh_msiof_transfer_one(struct spi_master *master,
rx_fifo = sh_msiof_spi_read_fifo_8;
} else if (bits <= 16) {
bytes_per_word = 2;
- if ((unsigned long)t->tx_buf & 0x01)
+ if ((unsigned long)tx_buf & 0x01)
tx_fifo = sh_msiof_spi_write_fifo_16u;
else
tx_fifo = sh_msiof_spi_write_fifo_16;

- if ((unsigned long)t->rx_buf & 0x01)
+ if ((unsigned long)rx_buf & 0x01)
rx_fifo = sh_msiof_spi_read_fifo_16u;
else
rx_fifo = sh_msiof_spi_read_fifo_16;
} else if (swab) {
bytes_per_word = 4;
- if ((unsigned long)t->tx_buf & 0x03)
+ if ((unsigned long)tx_buf & 0x03)
tx_fifo = sh_msiof_spi_write_fifo_s32u;
else
tx_fifo = sh_msiof_spi_write_fifo_s32;

- if ((unsigned long)t->rx_buf & 0x03)
+ if ((unsigned long)rx_buf & 0x03)
rx_fifo = sh_msiof_spi_read_fifo_s32u;
else
rx_fifo = sh_msiof_spi_read_fifo_s32;
} else {
bytes_per_word = 4;
- if ((unsigned long)t->tx_buf & 0x03)
+ if ((unsigned long)tx_buf & 0x03)
tx_fifo = sh_msiof_spi_write_fifo_32u;
else
tx_fifo = sh_msiof_spi_write_fifo_32;

- if ((unsigned long)t->rx_buf & 0x03)
+ if ((unsigned long)rx_buf & 0x03)
rx_fifo = sh_msiof_spi_read_fifo_32u;
else
rx_fifo = sh_msiof_spi_read_fifo_32;
@@ -676,20 +677,18 @@ static int sh_msiof_transfer_one(struct spi_master *master,
sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);

/* transfer in fifo sized chunks */
- words = t->len / bytes_per_word;
- bytes_done = 0;
-
- while (bytes_done < t->len) {
- void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL;
- const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL;
- n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
- tx_buf,
- rx_buf,
+ words = len / bytes_per_word;
+
+ while (words > 0) {
+ n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf,
words, bits);
if (n < 0)
return n;

- bytes_done += n * bytes_per_word;
+ if (tx_buf)
+ tx_buf += n * bytes_per_word;
+ if (rx_buf)
+ rx_buf += n * bytes_per_word;
words -= n;
}

--
1.9.1


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