[PATCH V2] SPI: DUAL and QUAD support
wangyuhang
wangyuhang2014 at gmail.com
Sat Jul 27 05:39:33 EDT 2013
Hi,
I corrected the previous patch as below.
1:dual and quad is still as the attribute in mode. Just like SPI_3WIRE,
dual and quad also can be regarded as a spi interface.
Another point, master->mode_bits and spi_device->mode will be checked
in spi_setup to prevend some mode that master dont support. It is
better than add new member and do redundant check operation.
2:To spidev, in order to backward compatible, still use
SPI_IOC_RD_MODE to deal with user who use <u8 mode>. Add
SPI_IOC_EXTRD_MODE to fix the <u16 mode>. And SPI_IOC_RD_LSB_FIRST
seems a little redundant, so del it.
Signed-off-by: wangyuhang <wangyuhang2014 at gmail.com>
---
drivers/spi/spi.c | 14 ++++++++++++++
drivers/spi/spidev.c | 39 +++++++++++++--------------------------
include/linux/spi/spi.h | 20 ++++++++++++++++++--
include/uapi/linux/spi/spidev.h | 20 +++++++++++++++-----
4 files changed, 60 insertions(+), 33 deletions(-)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 004b10f..dc6a7ba 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -868,6 +868,14 @@ static void of_register_spi_devices(struct spi_master *master)
spi->mode |= SPI_CS_HIGH;
if (of_find_property(nc, "spi-3wire", NULL))
spi->mode |= SPI_3WIRE;
+ if (of_find_property(nc, "spi-tx-dual", NULL))
+ spi->mode |= SPI_TX_DUAL;
+ if (of_find_property(nc, "spi-tx-quad", NULL))
+ spi->mode |= SPI_TX_QUAD;
+ if (of_find_property(nc, "spi-rx-dual", NULL))
+ spi->mode |= SPI_RX_DUAL;
+ if (of_find_property(nc, "spi-rx-quad", NULL))
+ spi->mode |= SPI_RX_QUAD;
/* Device speed */
prop = of_get_property(nc, "spi-max-frequency", &len);
@@ -1316,6 +1324,12 @@ int spi_setup(struct spi_device *spi)
/* help drivers fail *cleanly* when they need options
* that aren't supported with their current master
*/
+ if (((spi->mode >> 8) & 0x03) == 0x03 ||
+ ((spi->mode >> 10) & 0x03) == 0x03) {
+ dev_err(&spi->dev,
+ "setup: can not select dual and quad at the same time\n");
+ return -EINVAL;
+ }
bad_bits = spi->mode & ~spi->master->mode_bits;
if (bad_bits) {
dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 2e0655d..be96cb5 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -75,6 +75,9 @@ static DECLARE_BITMAP(minors, N_SPI_MINORS);
| SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
| SPI_NO_CS | SPI_READY)
+#define SPI_EXTMODE_MASK (SPI_MODE_MASK | SPI_TX_DUAL \
+ | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)
+
struct spidev_data {
dev_t devt;
spinlock_t spi_lock;
@@ -268,6 +271,8 @@ static int spidev_message(struct spidev_data *spidev,
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;
+ k_tmp->tx_nbits = u_tmp->tx_nbits;
+ k_tmp->rx_nbits = u_tmp->rx_nbits;
#ifdef VERBOSE
dev_dbg(&spidev->spi->dev,
" xfer len %zd %s%s%s%dbits %u usec %uHz\n",
@@ -359,10 +364,9 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
retval = __put_user(spi->mode & SPI_MODE_MASK,
(__u8 __user *)arg);
break;
- case SPI_IOC_RD_LSB_FIRST:
- retval = __put_user((spi->mode & SPI_LSB_FIRST) ? 1 : 0,
- (__u8 __user *)arg);
- break;
+ case SPI_IOC_EXTRD_MODE:
+ retval = __put_user(spi->mode & SPI_EXTMODE_MASK,
+ (__u16 __user *)arg);
case SPI_IOC_RD_BITS_PER_WORD:
retval = __put_user(spi->bits_per_word, (__u8 __user *)arg);
break;
@@ -372,17 +376,17 @@ 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) {
+ if (tmp & ~SPI_EXTMODE_MASK) {
retval = -EINVAL;
break;
}
- tmp |= spi->mode & ~SPI_MODE_MASK;
- spi->mode = (u8)tmp;
+ tmp |= spi->mode & ~SPI_EXTMODE_MASK;
+ spi->mode = (u16)tmp;
retval = spi_setup(spi);
if (retval < 0)
spi->mode = save;
@@ -390,23 +394,6 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
}
break;
- case SPI_IOC_WR_LSB_FIRST:
- retval = __get_user(tmp, (__u8 __user *)arg);
- if (retval == 0) {
- u8 save = spi->mode;
-
- if (tmp)
- spi->mode |= SPI_LSB_FIRST;
- else
- spi->mode &= ~SPI_LSB_FIRST;
- retval = spi_setup(spi);
- if (retval < 0)
- spi->mode = save;
- else
- dev_dbg(&spi->dev, "%csb first\n",
- tmp ? 'l' : 'm');
- }
- break;
case SPI_IOC_WR_BITS_PER_WORD:
retval = __get_user(tmp, (__u8 __user *)arg);
if (retval == 0) {
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 38c2b92..222e49e 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -74,7 +74,7 @@ struct spi_device {
struct spi_master *master;
u32 max_speed_hz;
u8 chip_select;
- u8 mode;
+ u16 mode;
#define SPI_CPHA 0x01 /* clock phase */
#define SPI_CPOL 0x02 /* clock polarity */
#define SPI_MODE_0 (0|0) /* (original MicroWire) */
@@ -87,6 +87,10 @@ struct spi_device {
#define SPI_LOOP 0x20 /* loopback mode */
#define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */
#define SPI_READY 0x80 /* slave pulls low to pause */
+#define SPI_TX_DUAL 0x100 /* transmit with 2 wires */
+#define SPI_TX_QUAD 0x200 /* transmit with 4 wires */
+#define SPI_RX_DUAL 0x400 /* receive with 2 wires */
+#define SPI_RX_QUAD 0x800 /* receive with 4 wires */
u8 bits_per_word;
int irq;
void *controller_state;
@@ -437,6 +441,8 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum);
* @rx_buf: data to be read (dma-safe memory), or NULL
* @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
* @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
+ * @tx_nbits: number of bits used for writting
+ * @rx_nbits: number of bits used for reading
* @len: size of rx and tx buffers (in bytes)
* @speed_hz: Select a speed other than the device default for this
* transfer. If 0 the default (from @spi_device) is used.
@@ -491,6 +497,11 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum);
* by the results of previous messages and where the whole transaction
* ends when the chipselect goes intactive.
*
+ * When SPI can transfer in 1x,2x or 4x. It can get this tranfer information
+ * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
+ * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
+ * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
+ *
* The code that submits an spi_message (and its spi_transfers)
* to the lower layers is responsible for managing its memory.
* Zero-initialize every field you don't set up explicitly, to
@@ -511,6 +522,11 @@ struct spi_transfer {
dma_addr_t rx_dma;
unsigned cs_change:1;
+ u8 tx_nbits;
+ u8 rx_nbits;
+#define SPI_NBITS_SINGLE 0x0; /* 1bit transfer */
+#define SPI_NBITS_DUAL 0x01; /* 2bits transfer */
+#define SPI_NBITS_QUAD 0x02; /* 4bits transfer */
u8 bits_per_word;
u16 delay_usecs;
u32 speed_hz;
@@ -858,7 +874,7 @@ struct spi_board_info {
/* mode becomes spi_device.mode, and is essential for chips
* where the default of SPI_CS_HIGH = 0 is wrong.
*/
- u8 mode;
+ u16 mode;
/* ... may need additional spi_device chip config data here.
* avoid stuff protocol drivers can set; but include stuff
diff --git a/include/uapi/linux/spi/spidev.h b/include/uapi/linux/spi/spidev.h
index 52d9ed0..5dc1e95 100644
--- a/include/uapi/linux/spi/spidev.h
+++ b/include/uapi/linux/spi/spidev.h
@@ -42,7 +42,14 @@
#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
+
+#define SPI_NBITS_SINGLE 0x0; /* 1bit transfer */
+#define SPI_NBITS_DUAL 0x01; /* 2bits transfer */
+#define SPI_NBITS_QUAD 0x02; /* 4bits transfer */
/*---------------------------------------------------------------------------*/
/* IOCTL commands */
@@ -54,6 +61,8 @@
* @tx_buf: Holds pointer to userspace buffer with transmit data, or null.
* If no data is provided, zeroes are shifted out.
* @rx_buf: Holds pointer to userspace buffer for receive data, or null.
+ * @tx_nbits: number of bits used for writting.
+ * @rx_nbits: number of bits used for reading.
* @len: Length of tx and rx buffers, in bytes.
* @speed_hz: Temporary override of the device's bitrate.
* @bits_per_word: Temporary override of the device's wordsize.
@@ -85,6 +94,8 @@
struct spi_ioc_transfer {
__u64 tx_buf;
__u64 rx_buf;
+ __u8 tx_nbits;
+ __u8 rx_nbits;
__u32 len;
__u32 speed_hz;
@@ -112,11 +123,10 @@ 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_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)
-#define SPI_IOC_WR_LSB_FIRST _IOW(SPI_IOC_MAGIC, 2, __u8)
+/* Read of SPI mode (including SPI DUAL/QUAD) */
+#define SPI_IOC_EXTRD_MODE _IOR(SPI_IOC_MAGIC, 2, __u16)
/* Read / Write SPI device word length (1..N) */
#define SPI_IOC_RD_BITS_PER_WORD _IOR(SPI_IOC_MAGIC, 3, __u8)
--
1.7.9.5
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