[PATCH 03/14] spi: rspi: Abstract 8/16-bit Data Register access

From: Geert Uytterhoeven
Date: Fri Jan 24 2014 - 03:47:19 EST


From: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
---
drivers/spi/spi-rspi.c | 56 ++++++++++++++++++++++++++++++------------------
1 file changed, 35 insertions(+), 21 deletions(-)

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 0e4d169c90d7..a0bb3c28ae91 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -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)
@@ -219,10 +220,25 @@ 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);
};
@@ -230,8 +246,7 @@ struct spi_ops {
/*
* 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;

@@ -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);
@@ -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;
@@ -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);
@@ -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--;
}
@@ -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--;
}
@@ -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);
@@ -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--;
@@ -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);
}
@@ -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--;
}

--
1.7.9.5

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