[PATCH] SPI: DUAL and QUAD support

[wangyuhang <wangyuhang2014-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Hi,

modify two things.
1:
>> @@ -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;
>> +       }
>> +               return -EINVAL;
>> +       }

>This code won't work if the constants you added for mode flags change
>value.  More importantly, anyone searching the code for SPI_TX_DUAL,
>etc. won't find this code.

so use the certain macro to replace.

2:
>You need to make sure that existing userspace binaries can run
>unmodified, changing the types will change the layout of the ioctl
>arguments.  This may mean that you need to add new ioctls if you need to
>change types.

I recovered the SPI_IOC_RD_LSB_FIRST ioctl.
Add new ioctl to fit u16 mode.
In addition,may SPI_IOC_RD_LSB_FIRST should be del in a better way.

Signed-off-by: wangyuhang <wangyuhang2014-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/spi/spi.c               |   14 ++++++++++++++
 drivers/spi/spidev.c            |   29 ++++++++++++++++++++++++++++-
 include/linux/spi/spi.h         |   20 ++++++++++++++++++--
 include/uapi/linux/spi/spidev.h |   17 ++++++++++++++++-
 4 files changed, 76 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 004b10f..3f6dc93 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 & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
+		((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
+		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..0b776de 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",
@@ -369,7 +374,10 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	case SPI_IOC_RD_MAX_SPEED_HZ:
 		retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg);
 		break;
-
+	case SPI_IOC_EXTRD_MODE:
+		retval = __put_user(spi->mode & SPI_EXTMODE_MASK,
+					(__u16 __user *)arg);
+		break;
 	/* write requests */
 	case SPI_IOC_WR_MODE:
 		retval = __get_user(tmp, (u8 __user *)arg);
@@ -433,6 +441,25 @@ spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 				dev_dbg(&spi->dev, "%d Hz (max)\n", tmp);
 		}
 		break;
+	case SPI_IOC_EXTWR_MODE:
+		retval = __get_user(tmp, (u16 __user *)arg);
+		if (retval == 0) {
+			u16	save = spi->mode;
+
+			if (tmp & ~SPI_EXTMODE_MASK) {
+				retval = -EINVAL;
+				break;
+			}
+
+			tmp |= spi->mode & ~SPI_EXTMODE_MASK;
+			spi->mode = (u16)tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->mode = save;
+			else
+				dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
+		}
+		break;
 
 	default:
 		/* segmented and/or full-duplex I/O request */
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..4d47e8a 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;
@@ -126,6 +137,10 @@ struct spi_ioc_transfer {
 #define SPI_IOC_RD_MAX_SPEED_HZ		_IOR(SPI_IOC_MAGIC, 4, __u32)
 #define SPI_IOC_WR_MAX_SPEED_HZ		_IOW(SPI_IOC_MAGIC, 4, __u32)
 
+/* Read / Write of SPI mode (including SPI DUAL/QUAD) */
+#define SPI_IOC_EXTRD_MODE		_IOR(SPI_IOC_MAGIC, 5, __u16)
+#define SPI_IOC_EXTWR_MODE		_IOW(SPI_IOC_MAGIC, 5, __u16)
+
 
 
 #endif /* SPIDEV_H */
-- 
1.7.9.5


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