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spi: rspi: Abstract 8/16-bit Data Register access
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Add rspi_{write,read}_data(), to abstract 8-bit (QSPI, and RSPI on RZ/A1H)
versus 16-bit (RSPI) Data Register access.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
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Geert Uytterhoeven authored and Mark Brown committed Jan 27, 2014
1 parent 79d2349 commit 74da768
Showing 1 changed file with 35 additions and 21 deletions.
56 changes: 35 additions & 21 deletions drivers/spi/spi-rspi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -192,6 +192,7 @@ struct rspi_data {

unsigned dma_width_16bit:1;
unsigned dma_callbacked:1;
unsigned byte_access:1;
};

static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
Expand Down Expand Up @@ -219,19 +220,33 @@ static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
return ioread16(rspi->addr + offset);
}

static void rspi_write_data(const struct rspi_data *rspi, u16 data)
{
if (rspi->byte_access)
rspi_write8(rspi, data, RSPI_SPDR);
else /* 16 bit */
rspi_write16(rspi, data, RSPI_SPDR);
}

static u16 rspi_read_data(const struct rspi_data *rspi)
{
if (rspi->byte_access)
return rspi_read8(rspi, RSPI_SPDR);
else /* 16 bit */
return rspi_read16(rspi, RSPI_SPDR);
}

/* optional functions */
struct spi_ops {
int (*set_config_register)(const struct rspi_data *rspi,
int access_size);
int (*set_config_register)(struct rspi_data *rspi, int access_size);
int (*send_pio)(struct rspi_data *rspi, struct spi_transfer *t);
int (*receive_pio)(struct rspi_data *rspi, struct spi_transfer *t);
};

/*
* functions for RSPI
*/
static int rspi_set_config_register(const struct rspi_data *rspi,
int access_size)
static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
{
int spbr;

Expand All @@ -242,8 +257,9 @@ static int rspi_set_config_register(const struct rspi_data *rspi,
spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1;
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);

/* Sets number of frames to be used: 1 frame */
rspi_write8(rspi, 0x00, RSPI_SPDCR);
/* Disable dummy transmission, set 16-bit word access, 1 frame */
rspi_write8(rspi, 0, RSPI_SPDCR);
rspi->byte_access = 0;

/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
Expand All @@ -266,8 +282,7 @@ static int rspi_set_config_register(const struct rspi_data *rspi,
/*
* functions for QSPI
*/
static int qspi_set_config_register(const struct rspi_data *rspi,
int access_size)
static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
{
u16 spcmd;
int spbr;
Expand All @@ -279,8 +294,9 @@ static int qspi_set_config_register(const struct rspi_data *rspi,
spbr = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz);
rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);

/* Sets number of frames to be used: 1 frame */
rspi_write8(rspi, 0x00, RSPI_SPDCR);
/* Disable dummy transmission, set byte access */
rspi_write8(rspi, 0, RSPI_SPDCR);
rspi->byte_access = 1;

/* Sets RSPCK, SSL, next-access delay value */
rspi_write8(rspi, 0x00, RSPI_SPCKD);
Expand Down Expand Up @@ -354,7 +370,7 @@ static int rspi_send_pio(struct rspi_data *rspi, struct spi_transfer *t)
return -ETIMEDOUT;
}

rspi_write16(rspi, *data, RSPI_SPDR);
rspi_write_data(rspi, *data);
data++;
remain--;
}
Expand All @@ -380,14 +396,14 @@ static int qspi_send_pio(struct rspi_data *rspi, struct spi_transfer *t)
"%s: tx empty timeout\n", __func__);
return -ETIMEDOUT;
}
rspi_write8(rspi, *data++, RSPI_SPDR);
rspi_write_data(rspi, *data++);

if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
dev_err(&rspi->master->dev,
"%s: receive timeout\n", __func__);
return -ETIMEDOUT;
}
rspi_read8(rspi, RSPI_SPDR);
rspi_read_data(rspi);

remain--;
}
Expand Down Expand Up @@ -525,7 +541,7 @@ static void rspi_receive_init(const struct rspi_data *rspi)

spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
rspi_read16(rspi, RSPI_SPDR); /* dummy read */
rspi_read_data(rspi); /* dummy read */
if (spsr & SPSR_OVRF)
rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
RSPI_SPSR);
Expand All @@ -549,15 +565,14 @@ static int rspi_receive_pio(struct rspi_data *rspi, struct spi_transfer *t)
return -ETIMEDOUT;
}
/* dummy write for generate clock */
rspi_write16(rspi, DUMMY_DATA, RSPI_SPDR);
rspi_write_data(rspi, DUMMY_DATA);

if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
dev_err(&rspi->master->dev,
"%s: receive timeout\n", __func__);
return -ETIMEDOUT;
}
/* SPDR allows 16 or 32-bit access only */
*data = (u8)rspi_read16(rspi, RSPI_SPDR);
*data = rspi_read_data(rspi);

data++;
remain--;
Expand All @@ -572,7 +587,7 @@ static void qspi_receive_init(const struct rspi_data *rspi)

spsr = rspi_read8(rspi, RSPI_SPSR);
if (spsr & SPSR_SPRF)
rspi_read8(rspi, RSPI_SPDR); /* dummy read */
rspi_read_data(rspi); /* dummy read */
rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
rspi_write8(rspi, 0x00, QSPI_SPBFCR);
}
Expand All @@ -593,15 +608,14 @@ static int qspi_receive_pio(struct rspi_data *rspi, struct spi_transfer *t)
return -ETIMEDOUT;
}
/* dummy write for generate clock */
rspi_write8(rspi, DUMMY_DATA, RSPI_SPDR);
rspi_write_data(rspi, DUMMY_DATA);

if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) {
dev_err(&rspi->master->dev,
"%s: receive timeout\n", __func__);
return -ETIMEDOUT;
}
/* SPDR allows 8, 16 or 32-bit access */
*data++ = rspi_read8(rspi, RSPI_SPDR);
*data++ = rspi_read_data(rspi);
remain--;
}

Expand Down

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