diff options
Diffstat (limited to 'Documentation/spi')
| -rw-r--r-- | Documentation/spi/00-INDEX | 22 | ||||
| -rw-r--r-- | Documentation/spi/spi-summary | 17 | ||||
| -rw-r--r-- | Documentation/spi/spidev | 6 | ||||
| -rw-r--r-- | Documentation/spi/spidev_fdx.c | 8 | ||||
| -rw-r--r-- | Documentation/spi/spidev_test.c | 45 |
5 files changed, 87 insertions, 11 deletions
diff --git a/Documentation/spi/00-INDEX b/Documentation/spi/00-INDEX new file mode 100644 index 000000000000..a128fa835512 --- /dev/null +++ b/Documentation/spi/00-INDEX @@ -0,0 +1,22 @@ +00-INDEX + - this file. +Makefile + - Makefile for the example sourcefiles. +butterfly + - AVR Butterfly SPI driver overview and pin configuration. +ep93xx_spi + - Basic EP93xx SPI driver configuration. +pxa2xx + - PXA2xx SPI master controller build by spi_message fifo wq +spidev + - Intro to the userspace API for spi devices +spidev_fdx.c + - spidev example file +spi-lm70llp + - Connecting an LM70-LLP sensor to the kernel via the SPI subsys. +spi-sc18is602 + - NXP SC18IS602/603 I2C-bus to SPI bridge +spi-summary + - (Linux) SPI overview. If unsure about SPI or SPI in Linux, start here. +spidev_test.c + - SPI testing utility. diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index f72e0d1e0da8..7982bcc4d151 100644 --- a/Documentation/spi/spi-summary +++ b/Documentation/spi/spi-summary @@ -543,7 +543,22 @@ SPI MASTER METHODS queuing transfers that arrive in the meantime. When the driver is finished with this message, it must call spi_finalize_current_message() so the subsystem can issue the next - transfer. This may sleep. + message. This may sleep. + + master->transfer_one(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *transfer) + The subsystem calls the driver to transfer a single transfer while + queuing transfers that arrive in the meantime. When the driver is + finished with this transfer, it must call + spi_finalize_current_transfer() so the subsystem can issue the next + transfer. This may sleep. Note: transfer_one and transfer_one_message + are mutually exclusive; when both are set, the generic subsystem does + not call your transfer_one callback. + + Return values: + negative errno: error + 0: transfer is finished + 1: transfer is still in progress DEPRECATED METHODS diff --git a/Documentation/spi/spidev b/Documentation/spi/spidev index ed2da5e5b28a..3d14035b1766 100644 --- a/Documentation/spi/spidev +++ b/Documentation/spi/spidev @@ -85,6 +85,12 @@ settings for data transfer parameters: SPI_MODE_0..SPI_MODE_3; or if you prefer you can combine SPI_CPOL (clock polarity, idle high iff this is set) or SPI_CPHA (clock phase, sample on trailing edge iff this is set) flags. + Note that this request is limited to SPI mode flags that fit in a + single byte. + + SPI_IOC_RD_MODE32, SPI_IOC_WR_MODE32 ... pass a pointer to a uin32_t + which will return (RD) or assign (WR) the full SPI transfer mode, + not limited to the bits that fit in one byte. SPI_IOC_RD_LSB_FIRST, SPI_IOC_WR_LSB_FIRST ... pass a pointer to a byte which will return (RD) or assign (WR) the bit justification used to diff --git a/Documentation/spi/spidev_fdx.c b/Documentation/spi/spidev_fdx.c index 36ec0774ca0b..0ea3e51292fc 100644 --- a/Documentation/spi/spidev_fdx.c +++ b/Documentation/spi/spidev_fdx.c @@ -78,10 +78,10 @@ static void do_msg(int fd, int len) static void dumpstat(const char *name, int fd) { - __u8 mode, lsb, bits; - __u32 speed; + __u8 lsb, bits; + __u32 mode, speed; - if (ioctl(fd, SPI_IOC_RD_MODE, &mode) < 0) { + if (ioctl(fd, SPI_IOC_RD_MODE32, &mode) < 0) { perror("SPI rd_mode"); return; } @@ -98,7 +98,7 @@ static void dumpstat(const char *name, int fd) return; } - printf("%s: spi mode %d, %d bits %sper word, %d Hz max\n", + printf("%s: spi mode 0x%x, %d bits %sper word, %d Hz max\n", name, mode, bits, lsb ? "(lsb first) " : "", speed); } diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c index 16feda901469..3a2f9d59edab 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 uint32_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"); @@ -81,7 +96,11 @@ static void print_usage(const char *prog) " -O --cpol clock polarity\n" " -L --lsb least significant bit first\n" " -C --cs-high chip select active high\n" - " -3 --3wire SI/SO signals shared\n"); + " -3 --3wire SI/SO signals shared\n" + " -N --no-cs no chip select\n" + " -R --ready slave pulls low to pause\n" + " -2 --dual dual transfer\n" + " -4 --quad quad transfer\n"); exit(1); } @@ -101,11 +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; @@ -147,11 +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[]) @@ -168,11 +201,11 @@ int main(int argc, char *argv[]) /* * spi mode */ - ret = ioctl(fd, SPI_IOC_WR_MODE, &mode); + ret = ioctl(fd, SPI_IOC_WR_MODE32, &mode); if (ret == -1) pabort("can't set spi mode"); - ret = ioctl(fd, SPI_IOC_RD_MODE, &mode); + ret = ioctl(fd, SPI_IOC_RD_MODE32, &mode); if (ret == -1) pabort("can't get spi mode"); @@ -198,7 +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: 0x%x\n", mode); printf("bits per word: %d\n", bits); printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000); |