From: Geert Uytterhoeven <geert+rene...@linux-m68k.org>
Add support for Dual/Quad SPI Transfers to the spidev API, and the
spidev_test test program.
This requires enlarging the mode from 8 to 16 bits.
Note that this does break binary compatibility with userspace.
Signed-off-by: Geert Uytterhoeven <geert+rene...@linux-m68k.org>
---
The Kconfig entry for SPI_SPIDEV states:
Note that this application programming interface is EXPERIMENTAL
and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes.
So it's OK to break binary compatibility?
Or should we introduce PI_IOC_RD_MODE16 and SPI_IOC_WR_MODE16 instead?
---
Documentation/spi/spidev_test.c | 39 +++++++++++++++++++++++++++++++++++----
drivers/spi/spidev.c | 17 ++++++++++-------
include/uapi/linux/spi/spidev.h | 12 +++++++++---
3 files changed, 54 insertions(+), 14 deletions(-)
diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c
index efd7385e907f..68c705b1326c 100644
--- a/Documentation/spi/spidev_test.c
+++ b/Documentation/spi/spidev_test.c
@@ -30,7 +30,7 @@ static void pabort(const char *s)
}
static const char *device = "/dev/spidev1.1";
-static uint8_t mode;
+static uint16_t mode;
static uint8_t bits = 8;
static uint32_t speed = 500000;
static uint16_t delay;
@@ -57,6 +57,21 @@ static void transfer(int fd)
.bits_per_word = bits,
};
+ if (mode & SPI_TX_QUAD)
+ tr.tx_nbits = 4;
+ else if (mode & SPI_TX_DUAL)
+ tr.tx_nbits = 2;
+ if (mode & SPI_RX_QUAD)
+ tr.rx_nbits = 4;
+ else if (mode & SPI_RX_DUAL)
+ tr.rx_nbits = 2;
+ if (!(mode & SPI_LOOP)) {
+ if (mode & (SPI_TX_QUAD | SPI_TX_DUAL))
+ tr.rx_buf = 0;
+ else if (mode & (SPI_RX_QUAD | SPI_RX_DUAL))
+ tr.tx_buf = 0;
+ }
+
ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
if (ret < 1)
pabort("can't send spi message");
@@ -83,7 +98,9 @@ static void print_usage(const char *prog)
" -C --cs-high chip select active high\n"
" -3 --3wire SI/SO signals shared\n"
" -N --no-cs no chip select\n"
- " -R --ready slave pulls low to pause\n");
+ " -R --ready slave pulls low to pause\n"
+ " -2 --dual dual transfer\n"
+ " -4 --quad quad transfer\n");
exit(1);
}
@@ -103,11 +120,13 @@ static void parse_opts(int argc, char *argv[])
{ "3wire", 0, 0, '3' },
{ "no-cs", 0, 0, 'N' },
{ "ready", 0, 0, 'R' },
+ { "dual", 0, 0, '2' },
+ { "quad", 0, 0, '4' },
{ NULL, 0, 0, 0 },
};
int c;
- c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR", lopts, NULL);
+ c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR24", lopts, NULL);
if (c == -1)
break;
@@ -149,11 +168,23 @@ static void parse_opts(int argc, char *argv[])
case 'R':
mode |= SPI_READY;
break;
+ case '2':
+ mode |= SPI_TX_DUAL;
+ break;
+ case '4':
+ mode |= SPI_TX_QUAD;
+ break;
default:
print_usage(argv[0]);
break;
}
}
+ if (mode & SPI_LOOP) {
+ if (mode & SPI_TX_DUAL)
+ mode |= SPI_RX_DUAL;
+ if (mode & SPI_TX_QUAD)
+ mode |= SPI_RX_QUAD;
+ }
}
int main(int argc, char *argv[])
@@ -200,7 +231,7 @@ int main(int argc, char *argv[])
if (ret == -1)
pabort("can't get max speed hz");
- printf("spi mode: %d\n", mode);
+ printf("spi mode: %x\n", mode);
printf("bits per word: %d\n", bits);
printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index d7c6e36021e8..e490e01db192 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -73,7 +73,8 @@ static DECLARE_BITMAP(minors, N_SPI_MINORS);
*/
#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
- | SPI_NO_CS | SPI_READY)
+ | SPI_NO_CS | SPI_READY | SPI_TX_DUAL \
+ | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)
struct spidev_data {
dev_t devt;
@@ -265,6 +266,8 @@ static int spidev_message(struct spidev_data *spidev,
buf += k_tmp->len;
k_tmp->cs_change = !!u_tmp->cs_change;
+ k_tmp->tx_nbits = u_tmp->tx_nbits;
+ k_tmp->rx_nbits = u_tmp->rx_nbits;
k_tmp->bits_per_word = u_tmp->bits_per_word;
k_tmp->delay_usecs = u_tmp->delay_usecs;
k_tmp->speed_hz = u_tmp->speed_hz;
@@ -357,7 +360,7 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned
long arg)
/* read requests */
case SPI_IOC_RD_MODE:
retval = __put_user(spi->mode & SPI_MODE_MASK,
- (__u8 __user *)arg);
+ (__u16 __user *)arg);
break;
case SPI_IOC_RD_LSB_FIRST:
retval = __put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0,
@@ -372,9 +375,9 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned
long arg)
/* write requests */
case SPI_IOC_WR_MODE:
- retval = __get_user(tmp, (u8 __user *)arg);
+ retval = __get_user(tmp, (u16 __user *)arg);
if (retval == 0) {
- u8 save = spi->mode;
+ u16 save = spi->mode;
if (tmp & ~SPI_MODE_MASK) {
retval = -EINVAL;
@@ -382,18 +385,18 @@ spidev_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
}
tmp |= spi->mode & ~SPI_MODE_MASK;
- spi->mode = (u8)tmp;
+ spi->mode = (u16)tmp;
retval = spi_setup(spi);
if (retval < 0)
spi->mode = save;
else
- dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
+ dev_dbg(&spi->dev, "spi mode %04x\n", tmp);
}
break;
case SPI_IOC_WR_LSB_FIRST:
retval = __get_user(tmp, (__u8 __user *)arg);
if (retval == 0) {
- u8 save = spi->mode;
+ u16 save = spi->mode;
if (tmp)
spi->mode |= SPI_LSB_FIRST;
diff --git a/include/uapi/linux/spi/spidev.h b/include/uapi/linux/spi/spidev.h
index 52d9ed01855f..50e8aef0e7ca 100644
--- a/include/uapi/linux/spi/spidev.h
+++ b/include/uapi/linux/spi/spidev.h
@@ -42,6 +42,10 @@
#define SPI_LOOP 0x20
#define SPI_NO_CS 0x40
#define SPI_READY 0x80
+#define SPI_TX_DUAL 0x100
+#define SPI_TX_QUAD 0x200
+#define SPI_RX_DUAL 0x400
+#define SPI_RX_QUAD 0x800
/*---------------------------------------------------------------------------*/
@@ -92,7 +96,9 @@ struct spi_ioc_transfer {
__u16 delay_usecs;
__u8 bits_per_word;
__u8 cs_change;
- __u32 pad;
+ __u8 tx_nbits;
+ __u8 rx_nbits;
+ __u16 pad;
/* If the contents of 'struct spi_ioc_transfer' ever change
* incompatibly, then the ioctl number (currently 0) must change;
@@ -111,8 +117,8 @@ struct spi_ioc_transfer {
/* Read / Write of SPI mode (SPI_MODE_0..SPI_MODE_3) */
-#define SPI_IOC_RD_MODE _IOR(SPI_IOC_MAGIC, 1, __u8)
-#define SPI_IOC_WR_MODE _IOW(SPI_IOC_MAGIC, 1, __u8)
+#define SPI_IOC_RD_MODE _IOR(SPI_IOC_MAGIC, 1, __u16)
+#define SPI_IOC_WR_MODE _IOW(SPI_IOC_MAGIC, 1, __u16)
/* Read / Write SPI bit justification */
#define SPI_IOC_RD_LSB_FIRST _IOR(SPI_IOC_MAGIC, 2, __u8)
--
1.7.9.5
--
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