spi: sh-msiof: Refactor sh_msiof_transfer_one()

- 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>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Geert Uytterhoeven 2014-06-20 12:16:19 +02:00 коммит произвёл Mark Brown
Родитель 75b82e23a4
Коммит 0312d59130
1 изменённых файлов: 20 добавлений и 21 удалений

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@ -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;
words = len / bytes_per_word;
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,
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;
}