diff options
Diffstat (limited to 'Documentation/spi')
| -rw-r--r-- | Documentation/spi/.gitignore | 2 | ||||
| -rw-r--r-- | Documentation/spi/00-INDEX | 22 | ||||
| -rw-r--r-- | Documentation/spi/Makefile | 11 | ||||
| -rw-r--r-- | Documentation/spi/ep93xx_spi | 105 | ||||
| -rw-r--r-- | Documentation/spi/pxa2xx | 47 | ||||
| -rw-r--r-- | Documentation/spi/spi-lm70llp | 12 | ||||
| -rw-r--r-- | Documentation/spi/spi-sc18is602 | 36 | ||||
| -rw-r--r-- | Documentation/spi/spi-summary | 110 | ||||
| -rw-r--r-- | Documentation/spi/spidev | 174 | ||||
| -rw-r--r-- | Documentation/spi/spidev_fdx.c | 158 | ||||
| -rw-r--r-- | Documentation/spi/spidev_test.c | 59 |
11 files changed, 519 insertions, 217 deletions
diff --git a/Documentation/spi/.gitignore b/Documentation/spi/.gitignore new file mode 100644 index 00000000000..4280576397e --- /dev/null +++ b/Documentation/spi/.gitignore @@ -0,0 +1,2 @@ +spidev_fdx +spidev_test diff --git a/Documentation/spi/00-INDEX b/Documentation/spi/00-INDEX new file mode 100644 index 00000000000..a128fa83551 --- /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/Makefile b/Documentation/spi/Makefile new file mode 100644 index 00000000000..a5b03c88bea --- /dev/null +++ b/Documentation/spi/Makefile @@ -0,0 +1,11 @@ +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o + +# List of programs to build +hostprogs-y := spidev_test spidev_fdx + +# Tell kbuild to always build the programs +always := $(hostprogs-y) + +HOSTCFLAGS_spidev_test.o += -I$(objtree)/usr/include +HOSTCFLAGS_spidev_fdx.o += -I$(objtree)/usr/include diff --git a/Documentation/spi/ep93xx_spi b/Documentation/spi/ep93xx_spi new file mode 100644 index 00000000000..832ddce6e5f --- /dev/null +++ b/Documentation/spi/ep93xx_spi @@ -0,0 +1,105 @@ +Cirrus EP93xx SPI controller driver HOWTO +========================================= + +ep93xx_spi driver brings SPI master support for EP93xx SPI controller. Chip +selects are implemented with GPIO lines. + +NOTE: If possible, don't use SFRMOUT (SFRM1) signal as a chip select. It will +not work correctly (it cannot be controlled by software). Use GPIO lines +instead. + +Sample configuration +==================== + +Typically driver configuration is done in platform board files (the files under +arch/arm/mach-ep93xx/*.c). In this example we configure MMC over SPI through +this driver on TS-7260 board. You can adapt the code to suit your needs. + +This example uses EGPIO9 as SD/MMC card chip select (this is wired in DIO1 +header on the board). + +You need to select CONFIG_MMC_SPI to use mmc_spi driver. + +arch/arm/mach-ep93xx/ts72xx.c: + +... +#include <linux/gpio.h> +#include <linux/spi/spi.h> + +#include <linux/platform_data/spi-ep93xx.h> + +/* this is our GPIO line used for chip select */ +#define MMC_CHIP_SELECT_GPIO EP93XX_GPIO_LINE_EGPIO9 + +static int ts72xx_mmc_spi_setup(struct spi_device *spi) +{ + int err; + + err = gpio_request(MMC_CHIP_SELECT_GPIO, spi->modalias); + if (err) + return err; + + gpio_direction_output(MMC_CHIP_SELECT_GPIO, 1); + + return 0; +} + +static void ts72xx_mmc_spi_cleanup(struct spi_device *spi) +{ + gpio_set_value(MMC_CHIP_SELECT_GPIO, 1); + gpio_direction_input(MMC_CHIP_SELECT_GPIO); + gpio_free(MMC_CHIP_SELECT_GPIO); +} + +static void ts72xx_mmc_spi_cs_control(struct spi_device *spi, int value) +{ + gpio_set_value(MMC_CHIP_SELECT_GPIO, value); +} + +static struct ep93xx_spi_chip_ops ts72xx_mmc_spi_ops = { + .setup = ts72xx_mmc_spi_setup, + .cleanup = ts72xx_mmc_spi_cleanup, + .cs_control = ts72xx_mmc_spi_cs_control, +}; + +static struct spi_board_info ts72xx_spi_devices[] __initdata = { + { + .modalias = "mmc_spi", + .controller_data = &ts72xx_mmc_spi_ops, + /* + * We use 10 MHz even though the maximum is 7.4 MHz. The driver + * will limit it automatically to max. frequency. + */ + .max_speed_hz = 10 * 1000 * 1000, + .bus_num = 0, + .chip_select = 0, + .mode = SPI_MODE_0, + }, +}; + +static struct ep93xx_spi_info ts72xx_spi_info = { + .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices), +}; + +static void __init ts72xx_init_machine(void) +{ + ... + ep93xx_register_spi(&ts72xx_spi_info, ts72xx_spi_devices, + ARRAY_SIZE(ts72xx_spi_devices)); +} + +The driver can use DMA for the transfers also. In this case ts72xx_spi_info +becomes: + +static struct ep93xx_spi_info ts72xx_spi_info = { + .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices), + .use_dma = true; +}; + +Note that CONFIG_EP93XX_DMA should be enabled as well. + +Thanks to +========= +Martin Guy, H. Hartley Sweeten and others who helped me during development of +the driver. Simplemachines.it donated me a Sim.One board which I used testing +the driver on EP9307. diff --git a/Documentation/spi/pxa2xx b/Documentation/spi/pxa2xx index f3853cc37bd..3352f97430e 100644 --- a/Documentation/spi/pxa2xx +++ b/Documentation/spi/pxa2xx @@ -2,7 +2,7 @@ PXA2xx SPI on SSP driver HOWTO =================================================== This a mini howto on the pxa2xx_spi driver. The driver turns a PXA2xx synchronous serial port into a SPI master controller -(see Documentation/spi/spi_summary). The driver has the following features +(see Documentation/spi/spi-summary). The driver has the following features - Support for any PXA2xx SSP - SSP PIO and SSP DMA data transfers. @@ -19,18 +19,14 @@ Declaring PXA2xx Master Controllers ----------------------------------- Typically a SPI master is defined in the arch/.../mach-*/board-*.c as a "platform device". The master configuration is passed to the driver via a table -found in include/asm-arm/arch-pxa/pxa2xx_spi.h: +found in include/linux/spi/pxa2xx_spi.h: struct pxa2xx_spi_master { - enum pxa_ssp_type ssp_type; u32 clock_enable; u16 num_chipselect; u8 enable_dma; }; -The "pxa2xx_spi_master.ssp_type" field must have a value between 1 and 3 and -informs the driver which features a particular SSP supports. - The "pxa2xx_spi_master.clock_enable" field is used to enable/disable the corresponding SSP peripheral block in the "Clock Enable Register (CKEN"). See the "PXA2xx Developer Manual" section "Clocks and Power Management". @@ -61,7 +57,6 @@ static struct resource pxa_spi_nssp_resources[] = { }; static struct pxa2xx_spi_master pxa_nssp_master_info = { - .ssp_type = PXA25x_NSSP, /* Type of SSP */ .clock_enable = CKEN_NSSP, /* NSSP Peripheral clock */ .num_chipselect = 1, /* Matches the number of chips attached to NSSP */ .enable_dma = 1, /* Enables NSSP DMA */ @@ -90,13 +85,13 @@ Declaring Slave Devices ----------------------- Typically each SPI slave (chip) is defined in the arch/.../mach-*/board-*.c using the "spi_board_info" structure found in "linux/spi/spi.h". See -"Documentation/spi/spi_summary" for additional information. +"Documentation/spi/spi-summary" for additional information. Each slave device attached to the PXA must provide slave specific configuration information via the structure "pxa2xx_spi_chip" found in -"include/asm-arm/arch-pxa/pxa2xx_spi.h". The pxa2xx_spi master controller driver +"include/linux/spi/pxa2xx_spi.h". The pxa2xx_spi master controller driver will uses the configuration whenever the driver communicates with the slave -device. +device. All fields are optional. struct pxa2xx_spi_chip { u8 tx_threshold; @@ -112,14 +107,17 @@ used to configure the SSP hardware fifo. These fields are critical to the performance of pxa2xx_spi driver and misconfiguration will result in rx fifo overruns (especially in PIO mode transfers). Good default values are - .tx_threshold = 12, - .rx_threshold = 4, + .tx_threshold = 8, + .rx_threshold = 8, + +The range is 1 to 16 where zero indicates "use default". The "pxa2xx_spi_chip.dma_burst_size" field is used to configure PXA2xx DMA engine and is related the "spi_device.bits_per_word" field. Read and understand the PXA2xx "Developer Manual" sections on the DMA controller and SSP Controllers to determine the correct value. An SSP configured for byte-wide transfers would -use a value of 8. +use a value of 8. The driver will determine a reasonable default if +dma_burst_size == 0. The "pxa2xx_spi_chip.timeout" fields is used to efficiently handle trailing bytes in the SSP receiver fifo. The correct value for this field is @@ -137,7 +135,13 @@ function for asserting/deasserting a slave device chip select. If the field is NULL, the pxa2xx_spi master controller driver assumes that the SSP port is configured to use SSPFRM instead. -NSSP SALVE SAMPLE +NOTE: the SPI driver cannot control the chip select if SSPFRM is used, so the +chipselect is dropped after each spi_transfer. Most devices need chip select +asserted around the complete message. Use SSPFRM as a GPIO (through cs_control) +to accommodate these chips. + + +NSSP SLAVE SAMPLE ----------------- The pxa2xx_spi_chip structure is passed to the pxa2xx_spi driver in the "spi_board_info.controller_data" field. Below is a sample configuration using @@ -206,18 +210,21 @@ static void __init streetracer_init(void) DMA and PIO I/O Support ----------------------- -The pxa2xx_spi driver support both DMA and interrupt driven PIO message -transfers. The driver defaults to PIO mode and DMA transfers must enabled by -setting the "enable_dma" flag in the "pxa2xx_spi_master" structure and -ensuring that the "pxa2xx_spi_chip.dma_burst_size" field is non-zero. The DMA -mode support both coherent and stream based DMA mappings. +The pxa2xx_spi driver supports both DMA and interrupt driven PIO message +transfers. The driver defaults to PIO mode and DMA transfers must be enabled +by setting the "enable_dma" flag in the "pxa2xx_spi_master" structure. The DMA +mode supports both coherent and stream based DMA mappings. The following logic is used to determine the type of I/O to be used on a per "spi_transfer" basis: -if !enable_dma or dma_burst_size == 0 then +if !enable_dma then always use PIO transfers +if spi_message.len > 8191 then + print "rate limited" warning + use PIO transfers + if spi_message.is_dma_mapped and rx_dma_buf != 0 and tx_dma_buf != 0 then use coherent DMA mode diff --git a/Documentation/spi/spi-lm70llp b/Documentation/spi/spi-lm70llp index 154bd02220b..463f6d01fa1 100644 --- a/Documentation/spi/spi-lm70llp +++ b/Documentation/spi/spi-lm70llp @@ -13,10 +13,20 @@ Description This driver provides glue code connecting a National Semiconductor LM70 LLP temperature sensor evaluation board to the kernel's SPI core subsystem. +This is a SPI master controller driver. It can be used in conjunction with +(layered under) the LM70 logical driver (a "SPI protocol driver"). In effect, this driver turns the parallel port interface on the eval board into a SPI bus with a single device, which will be driven by the generic LM70 driver (drivers/hwmon/lm70.c). + +Hardware Interfacing +-------------------- +The schematic for this particular board (the LM70EVAL-LLP) is +available (on page 4) here: + + http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf + The hardware interfacing on the LM70 LLP eval board is as follows: Parallel LM70 LLP @@ -36,7 +46,7 @@ The hardware interfacing on the LM70 LLP eval board is as follows: Note that since the LM70 uses a "3-wire" variant of SPI, the SI/SO pin is connected to both pin D7 (as Master Out) and Select (as Master In) -using an arrangment that lets either the parport or the LM70 pull the +using an arrangement that lets either the parport or the LM70 pull the pin low. This can't be shared with true SPI devices, but other 3-wire devices might share the same SI/SO pin. diff --git a/Documentation/spi/spi-sc18is602 b/Documentation/spi/spi-sc18is602 new file mode 100644 index 00000000000..a45702865a3 --- /dev/null +++ b/Documentation/spi/spi-sc18is602 @@ -0,0 +1,36 @@ +Kernel driver spi-sc18is602 +=========================== + +Supported chips: + * NXP SI18IS602/602B/603 + Datasheet: http://www.nxp.com/documents/data_sheet/SC18IS602_602B_603.pdf + +Author: + Guenter Roeck <linux@roeck-us.net> + + +Description +----------- + +This driver provides connects a NXP SC18IS602/603 I2C-bus to SPI bridge to the +kernel's SPI core subsystem. + +The driver does not probe for supported chips, since the SI18IS602/603 does not +support Chip ID registers. You will have to instantiate the devices explicitly. +Please see Documentation/i2c/instantiating-devices for details. + + +Usage Notes +----------- + +This driver requires the I2C adapter driver to support raw I2C messages. I2C +adapter drivers which can only handle the SMBus protocol are not supported. + +The maximum SPI message size supported by SC18IS602/603 is 200 bytes. Attempts +to initiate longer transfers will fail with -EINVAL. EEPROM read operations and +similar large accesses have to be split into multiple chunks of no more than +200 bytes per SPI message (128 bytes of data per message is recommended). This +means that programs such as "cp" or "od", which automatically use large block +sizes to access a device, can not be used directly to read data from EEPROM. +Programs such as dd, where the block size can be specified, should be used +instead. diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index 8861e47e5a2..7982bcc4d15 100644 --- a/Documentation/spi/spi-summary +++ b/Documentation/spi/spi-summary @@ -1,7 +1,7 @@ Overview of Linux kernel SPI support ==================================== -21-May-2007 +02-Feb-2012 What is SPI? ------------ @@ -34,7 +34,7 @@ SPI slave functions are usually not interoperable between vendors - It may also be used to stream data in either direction (half duplex), or both of them at the same time (full duplex). - - Some devices may use eight bit words. Others may different word + - Some devices may use eight bit words. Others may use different word lengths, such as streams of 12-bit or 20-bit digital samples. - Words are usually sent with their most significant bit (MSB) first, @@ -116,6 +116,13 @@ low order bit. So when a chip's timing diagram shows the clock starting low (CPOL=0) and data stabilized for sampling during the trailing clock edge (CPHA=1), that's SPI mode 1. +Note that the clock mode is relevant as soon as the chipselect goes +active. So the master must set the clock to inactive before selecting +a slave, and the slave can tell the chosen polarity by sampling the +clock level when its select line goes active. That's why many devices +support for example both modes 0 and 3: they don't care about polarity, +and always clock data in/out on rising clock edges. + How do these driver programming interfaces work? ------------------------------------------------ @@ -132,7 +139,7 @@ a command and then reading its response. There are two types of SPI driver, here called: - Controller drivers ... controllers may be built in to System-On-Chip + Controller drivers ... controllers may be built into System-On-Chip processors, and often support both Master and Slave roles. These drivers touch hardware registers and may use DMA. Or they can be PIO bitbangers, needing just GPIO pins. @@ -203,12 +210,12 @@ board should normally be set up and registered. So for example arch/.../mach-*/board-*.c files might have code like: - #include <asm/arch/spi.h> /* for mysoc_spi_data */ + #include <mach/spi.h> /* for mysoc_spi_data */ /* if your mach-* infrastructure doesn't support kernels that can * run on multiple boards, pdata wouldn't benefit from "__init". */ - static struct mysoc_spi_data __init pdata = { ... }; + static struct mysoc_spi_data pdata __initdata = { ... }; static __init board_init(void) { @@ -220,7 +227,7 @@ So for example arch/.../mach-*/board-*.c files might have code like: And SOC-specific utility code might look something like: - #include <asm/arch/spi.h> + #include <mach/spi.h> static struct platform_device spi2 = { ... }; @@ -338,17 +345,17 @@ SPI protocol drivers somewhat resemble platform device drivers: }, .probe = CHIP_probe, - .remove = __devexit_p(CHIP_remove), + .remove = CHIP_remove, .suspend = CHIP_suspend, .resume = CHIP_resume, }; -The driver core will autmatically attempt to bind this driver to any SPI +The driver core will automatically attempt to bind this driver to any SPI device whose board_info gave a modalias of "CHIP". Your probe() code might look like this unless you're creating a device which is managing a bus (appearing under /sys/class/spi_master). - static int __devinit CHIP_probe(struct spi_device *spi) + static int CHIP_probe(struct spi_device *spi) { struct CHIP *chip; struct CHIP_platform_data *pdata; @@ -379,8 +386,14 @@ any more such messages. + when bidirectional reads and writes start ... by how its sequence of spi_transfer requests is arranged; + + which I/O buffers are used ... each spi_transfer wraps a + buffer for each transfer direction, supporting full duplex + (two pointers, maybe the same one in both cases) and half + duplex (one pointer is NULL) transfers; + + optionally defining short delays after transfers ... using - the spi_transfer.delay_usecs setting; + the spi_transfer.delay_usecs setting (this delay can be the + only protocol effect, if the buffer length is zero); + whether the chipselect becomes inactive after a transfer and any delay ... by using the spi_transfer.cs_change flag; @@ -470,9 +483,9 @@ also initialize its own internal state. (See below about bus numbering and those methods.) After you initialize the spi_master, then use spi_register_master() to -publish it to the rest of the system. At that time, device nodes for -the controller and any predeclared spi devices will be made available, -and the driver model core will take care of binding them to drivers. +publish it to the rest of the system. At that time, device nodes for the +controller and any predeclared spi devices will be made available, and +the driver model core will take care of binding them to drivers. If you need to remove your SPI controller driver, spi_unregister_master() will reverse the effect of spi_register_master(). @@ -498,28 +511,81 @@ SPI MASTER METHODS This sets up the device clock rate, SPI mode, and word sizes. Drivers may change the defaults provided by board_info, and then call spi_setup(spi) to invoke this routine. It may sleep. + Unless each SPI slave has its own configuration registers, don't change them right away ... otherwise drivers could corrupt I/O that's in progress for other SPI devices. - master->transfer(struct spi_device *spi, struct spi_message *message) - This must not sleep. Its responsibility is arrange that the - transfer happens and its complete() callback is issued. The two - will normally happen later, after other transfers complete, and - if the controller is idle it will need to be kickstarted. + ** BUG ALERT: for some reason the first version of + ** many spi_master drivers seems to get this wrong. + ** When you code setup(), ASSUME that the controller + ** is actively processing transfers for another device. master->cleanup(struct spi_device *spi) Your controller driver may use spi_device.controller_state to hold state it dynamically associates with that device. If you do that, be sure to provide the cleanup() method to free that state. + master->prepare_transfer_hardware(struct spi_master *master) + This will be called by the queue mechanism to signal to the driver + that a message is coming in soon, so the subsystem requests the + driver to prepare the transfer hardware by issuing this call. + This may sleep. + + master->unprepare_transfer_hardware(struct spi_master *master) + This will be called by the queue mechanism to signal to the driver + that there are no more messages pending in the queue and it may + relax the hardware (e.g. by power management calls). This may sleep. + + master->transfer_one_message(struct spi_master *master, + struct spi_message *mesg) + The subsystem calls the driver to transfer a single message while + 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 + 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 + + master->transfer(struct spi_device *spi, struct spi_message *message) + This must not sleep. Its responsibility is to arrange that the + transfer happens and its complete() callback is issued. The two + will normally happen later, after other transfers complete, and + if the controller is idle it will need to be kickstarted. This + method is not used on queued controllers and must be NULL if + transfer_one_message() and (un)prepare_transfer_hardware() are + implemented. + SPI MESSAGE QUEUE -The bulk of the driver will be managing the I/O queue fed by transfer(). +If you are happy with the standard queueing mechanism provided by the +SPI subsystem, just implement the queued methods specified above. Using +the message queue has the upside of centralizing a lot of code and +providing pure process-context execution of methods. The message queue +can also be elevated to realtime priority on high-priority SPI traffic. + +Unless the queueing mechanism in the SPI subsystem is selected, the bulk +of the driver will be managing the I/O queue fed by the now deprecated +function transfer(). That queue could be purely conceptual. For example, a driver used only -for low-frequency sensor acess might be fine using synchronous PIO. +for low-frequency sensor access might be fine using synchronous PIO. But the queue will probably be very real, using message->queue, PIO, often DMA (especially if the root filesystem is in SPI flash), and @@ -542,4 +608,6 @@ Stephen Street Mark Underwood Andrew Victor Vitaly Wool - +Grant Likely +Mark Brown +Linus Walleij diff --git a/Documentation/spi/spidev b/Documentation/spi/spidev index 5c8e1b988a0..3d14035b176 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 @@ -126,8 +132,8 @@ NOTES: FULL DUPLEX CHARACTER DEVICE API ================================ -See the sample program below for one example showing the use of the full -duplex programming interface. (Although it doesn't perform a full duplex +See the spidev_fdx.c sample program for one example showing the use of the +full duplex programming interface. (Although it doesn't perform a full duplex transfer.) The model is the same as that used in the kernel spi_sync() request; the individual transfers offer the same capabilities as are available to kernel drivers (except that it's not asynchronous). @@ -141,167 +147,3 @@ and bitrate for each transfer segment.) To make a full duplex request, provide both rx_buf and tx_buf for the same transfer. It's even OK if those are the same buffer. - - -SAMPLE PROGRAM -============== - --------------------------------- CUT HERE -#include <stdio.h> -#include <unistd.h> -#include <stdlib.h> -#include <fcntl.h> -#include <string.h> - -#include <sys/ioctl.h> -#include <sys/types.h> -#include <sys/stat.h> - -#include <linux/types.h> -#include <linux/spi/spidev.h> - - -static int verbose; - -static void do_read(int fd, int len) -{ - unsigned char buf[32], *bp; - int status; - - /* read at least 2 bytes, no more than 32 */ - if (len < 2) - len = 2; - else if (len > sizeof(buf)) - len = sizeof(buf); - memset(buf, 0, sizeof buf); - - status = read(fd, buf, len); - if (status < 0) { - perror("read"); - return; - } - if (status != len) { - fprintf(stderr, "short read\n"); - return; - } - - printf("read(%2d, %2d): %02x %02x,", len, status, - buf[0], buf[1]); - status -= 2; - bp = buf + 2; - while (status-- > 0) - printf(" %02x", *bp++); - printf("\n"); -} - -static void do_msg(int fd, int len) -{ - struct spi_ioc_transfer xfer[2]; - unsigned char buf[32], *bp; - int status; - - memset(xfer, 0, sizeof xfer); - memset(buf, 0, sizeof buf); - - if (len > sizeof buf) - len = sizeof buf; - - buf[0] = 0xaa; - xfer[0].tx_buf = (__u64) buf; - xfer[0].len = 1; - - xfer[1].rx_buf = (__u64) buf; - xfer[1].len = len; - - status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer); - if (status < 0) { - perror("SPI_IOC_MESSAGE"); - return; - } - - printf("response(%2d, %2d): ", len, status); - for (bp = buf; len; len--) - printf(" %02x", *bp++); - printf("\n"); -} - -static void dumpstat(const char *name, int fd) -{ - __u8 mode, lsb, bits; - __u32 speed; - - if (ioctl(fd, SPI_IOC_RD_MODE, &mode) < 0) { - perror("SPI rd_mode"); - return; - } - if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) { - perror("SPI rd_lsb_fist"); - return; - } - if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) { - perror("SPI bits_per_word"); - return; - } - if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) { - perror("SPI max_speed_hz"); - return; - } - - printf("%s: spi mode %d, %d bits %sper word, %d Hz max\n", - name, mode, bits, lsb ? "(lsb first) " : "", speed); -} - -int main(int argc, char **argv) -{ - int c; - int readcount = 0; - int msglen = 0; - int fd; - const char *name; - - while ((c = getopt(argc, argv, "hm:r:v")) != EOF) { - switch (c) { - case 'm': - msglen = atoi(optarg); - if (msglen < 0) - goto usage; - continue; - case 'r': - readcount = atoi(optarg); - if (readcount < 0) - goto usage; - continue; - case 'v': - verbose++; - continue; - case 'h': - case '?': -usage: - fprintf(stderr, - "usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n", - argv[0]); - return 1; - } - } - - if ((optind + 1) != argc) - goto usage; - name = argv[optind]; - - fd = open(name, O_RDWR); - if (fd < 0) { - perror("open"); - return 1; - } - - dumpstat(name, fd); - - if (msglen) - do_msg(fd, msglen); - - if (readcount) - do_read(fd, readcount); - - close(fd); - return 0; -} diff --git a/Documentation/spi/spidev_fdx.c b/Documentation/spi/spidev_fdx.c new file mode 100644 index 00000000000..0ea3e51292f --- /dev/null +++ b/Documentation/spi/spidev_fdx.c @@ -0,0 +1,158 @@ +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <fcntl.h> +#include <string.h> + +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include <linux/types.h> +#include <linux/spi/spidev.h> + + +static int verbose; + +static void do_read(int fd, int len) +{ + unsigned char buf[32], *bp; + int status; + + /* read at least 2 bytes, no more than 32 */ + if (len < 2) + len = 2; + else if (len > sizeof(buf)) + len = sizeof(buf); + memset(buf, 0, sizeof buf); + + status = read(fd, buf, len); + if (status < 0) { + perror("read"); + return; + } + if (status != len) { + fprintf(stderr, "short read\n"); + return; + } + + printf("read(%2d, %2d): %02x %02x,", len, status, + buf[0], buf[1]); + status -= 2; + bp = buf + 2; + while (status-- > 0) + printf(" %02x", *bp++); + printf("\n"); +} + +static void do_msg(int fd, int len) +{ + struct spi_ioc_transfer xfer[2]; + unsigned char buf[32], *bp; + int status; + + memset(xfer, 0, sizeof xfer); + memset(buf, 0, sizeof buf); + + if (len > sizeof buf) + len = sizeof buf; + + buf[0] = 0xaa; + xfer[0].tx_buf = (unsigned long)buf; + xfer[0].len = 1; + + xfer[1].rx_buf = (unsigned long) buf; + xfer[1].len = len; + + status = ioctl(fd, SPI_IOC_MESSAGE(2), xfer); + if (status < 0) { + perror("SPI_IOC_MESSAGE"); + return; + } + + printf("response(%2d, %2d): ", len, status); + for (bp = buf; len; len--) + printf(" %02x", *bp++); + printf("\n"); +} + +static void dumpstat(const char *name, int fd) +{ + __u8 lsb, bits; + __u32 mode, speed; + + if (ioctl(fd, SPI_IOC_RD_MODE32, &mode) < 0) { + perror("SPI rd_mode"); + return; + } + if (ioctl(fd, SPI_IOC_RD_LSB_FIRST, &lsb) < 0) { + perror("SPI rd_lsb_fist"); + return; + } + if (ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits) < 0) { + perror("SPI bits_per_word"); + return; + } + if (ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed) < 0) { + perror("SPI max_speed_hz"); + return; + } + + printf("%s: spi mode 0x%x, %d bits %sper word, %d Hz max\n", + name, mode, bits, lsb ? "(lsb first) " : "", speed); +} + +int main(int argc, char **argv) +{ + int c; + int readcount = 0; + int msglen = 0; + int fd; + const char *name; + + while ((c = getopt(argc, argv, "hm:r:v")) != EOF) { + switch (c) { + case 'm': + msglen = atoi(optarg); + if (msglen < 0) + goto usage; + continue; + case 'r': + readcount = atoi(optarg); + if (readcount < 0) + goto usage; + continue; + case 'v': + verbose++; + continue; + case 'h': + case '?': +usage: + fprintf(stderr, + "usage: %s [-h] [-m N] [-r N] /dev/spidevB.D\n", + argv[0]); + return 1; + } + } + + if ((optind + 1) != argc) + goto usage; + name = argv[optind]; + + fd = open(name, O_RDWR); + if (fd < 0) { + perror("open"); + return 1; + } + + dumpstat(name, fd); + + if (msglen) + do_msg(fd, msglen); + + if (readcount) + do_read(fd, readcount); + + close(fd); + return 0; +} diff --git a/Documentation/spi/spidev_test.c b/Documentation/spi/spidev_test.c index cf0e3ce0d52..3a2f9d59eda 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; @@ -57,8 +57,23 @@ 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) + if (ret < 1) pabort("can't send spi message"); for (ret = 0; ret < ARRAY_SIZE(tx); ret++) { @@ -69,7 +84,7 @@ static void transfer(int fd) puts(""); } -void print_usage(const char *prog) +static void print_usage(const char *prog) { printf("Usage: %s [-DsbdlHOLC3]\n", prog); puts(" -D --device device to use (default /dev/spidev1.1)\n" @@ -81,11 +96,15 @@ 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); } -void parse_opts(int argc, char *argv[]) +static void parse_opts(int argc, char *argv[]) { while (1) { static const struct option lopts[] = { @@ -99,11 +118,15 @@ void parse_opts(int argc, char *argv[]) { "lsb", 0, 0, 'L' }, { "cs-high", 0, 0, 'C' }, { "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:lHOLC3", lopts, NULL); + c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR24", lopts, NULL); if (c == -1) break; @@ -139,11 +162,29 @@ void parse_opts(int argc, char *argv[]) case '3': mode |= SPI_3WIRE; break; + case 'N': + mode |= SPI_NO_CS; + break; + 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[]) @@ -160,11 +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"); @@ -190,7 +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); |