inexpensive battery powered microcontroller evaluation board.
This same cable can be used to flash new firmware.
-config SPI_BUTTERFLY
- tristate "Parallel port adapter for AVR Butterfly (DEVELOPMENT)"
- depends on SPI_MASTER && PARPORT && EXPERIMENTAL
+config SPI_MPC83xx
+ tristate "Freescale MPC83xx SPI controller"
+ depends on SPI_MASTER && PPC_83xx && EXPERIMENTAL
select SPI_BITBANG
help
- This uses a custom parallel port cable to connect to an AVR
- Butterfly <http://www.atmel.com/products/avr/butterfly>, an
- inexpensive battery powered microcontroller evaluation board.
- This same cable can be used to flash new firmware.
+ This enables using the Freescale MPC83xx SPI controller in master
+ mode.
+
+ Note, this driver uniquely supports the SPI controller on the MPC83xx
+ family of PowerPC processors. The MPC83xx uses a simple set of shift
+ registers for data (opposed to the CPM based descriptor model).
+
+config SPI_PXA2XX
+ tristate "PXA2xx SSP SPI master"
+ depends on SPI_MASTER && ARCH_PXA && EXPERIMENTAL
+ help
+ This enables using a PXA2xx SSP port as a SPI master controller.
+ The driver can be configured to use any SSP port and additional
+ documentation can be found a Documentation/spi/pxa2xx.
+
+config SPI_S3C24XX_GPIO
+ tristate "Samsung S3C24XX series SPI by GPIO"
+ depends on SPI_MASTER && ARCH_S3C2410 && SPI_BITBANG && EXPERIMENTAL
+ help
+ SPI driver for Samsung S3C24XX series ARM SoCs using
+ GPIO lines to provide the SPI bus. This can be used where
+ the inbuilt hardware cannot provide the transfer mode, or
+ where the board is using non hardware connected pins.
config SPI_OMAP_UWIRE
tristate "OMAP MicroWire"
#
+config SPI_S3C24XX
+ tristate "Samsung S3C24XX series SPI"
+ depends on SPI_MASTER && ARCH_S3C2410 && EXPERIMENTAL
+ help
+ SPI driver for Samsung S3C24XX series ARM SoCs
+
#
# There are lots of SPI device types, with sensors and memory
# being probably the most widely used ones.
/* nsecs = (clock period)/2 */
if (!hz)
hz = spi->max_speed_hz;
- cs->nsecs = (1000000000/2) / hz;
- if (cs->nsecs > MAX_UDELAY_MS * 1000)
- return -EINVAL;
+ if (hz) {
+ cs->nsecs = (1000000000/2) / hz;
+ if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000))
+ return -EINVAL;
+ }
return 0;
}
struct spi_bitbang *bitbang;
int retval;
- if (!spi->max_speed_hz)
+ bitbang = spi_master_get_devdata(spi->master);
+
+ /* REVISIT: some systems will want to support devices using lsb-first
+ * bit encodings on the wire. In pure software that would be trivial,
+ * just bitbang_txrx_le_cphaX() routines shifting the other way, and
+ * some hardware controllers also have this support.
+ */
+ if ((spi->mode & SPI_LSB_FIRST) != 0)
return -EINVAL;
if (!cs) {
return -ENOMEM;
spi->controller_state = cs;
}
- bitbang = spi_master_get_devdata(spi->master);
if (!spi->bits_per_word)
spi->bits_per_word = 8;
if (retval < 0)
return retval;
- dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
+ dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n",
__FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
spi->bits_per_word, 2 * cs->nsecs);
{
struct spi_bitbang *bitbang;
unsigned long flags;
+ int status = 0;
m->actual_length = 0;
m->status = -EINPROGRESS;
return -ESHUTDOWN;
spin_lock_irqsave(&bitbang->lock, flags);
- list_add_tail(&m->queue, &bitbang->queue);
- queue_work(bitbang->workqueue, &bitbang->work);
+ if (!spi->max_speed_hz)
+ status = -ENETDOWN;
+ else {
+ list_add_tail(&m->queue, &bitbang->queue);
+ queue_work(bitbang->workqueue, &bitbang->work);
+ }
spin_unlock_irqrestore(&bitbang->lock, flags);
- return 0;
+ return status;
}
EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
* @chip-select: Chipselect, distinguishing chips handled by "master".
* @mode: The spi mode defines how data is clocked out and in.
* This may be changed by the device's driver.
+ * The "active low" default for chipselect mode can be overridden,
+ * as can the "MSB first" default for each word in a transfer.
* @bits_per_word: Data transfers involve one or more words; word sizes
- * like eight or 12 bits are common. In-memory wordsizes are
+ * like eight or 12 bits are common. In-memory wordsizes are
* powers of two bytes (e.g. 20 bit samples use 32 bits).
- * This may be changed by the device's driver.
+ * This may be changed by the device's driver, or left at the
+ * default (0) indicating protocol words are eight bit bytes.
* The spi_transfer.bits_per_word can override this for each transfer.
* @irq: Negative, or the number passed to request_irq() to receive
- * interrupts from this device.
+ * interrupts from this device.
* @controller_state: Controller's runtime state
* @controller_data: Board-specific definitions for controller, such as
- * FIFO initialization parameters; from board_info.controller_data
+ * FIFO initialization parameters; from board_info.controller_data
*
* An spi_device is used to interchange data between an SPI slave
* (usually a discrete chip) and CPU memory.
#define SPI_MODE_2 (SPI_CPOL|0)
#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
#define SPI_CS_HIGH 0x04 /* chipselect active high? */
+#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
u8 bits_per_word;
int irq;
void *controller_state;
// likely need more hooks for more protocol options affecting how
// the controller talks to each chip, like:
- // - bit order (default is wordwise msb-first)
// - memory packing (12 bit samples into low bits, others zeroed)
// - priority
// - drop chipselect after each word
* struct spi_master - interface to SPI master controller
* @cdev: class interface to this driver
* @bus_num: board-specific (and often SOC-specific) identifier for a
- * given SPI controller.
+ * given SPI controller.
* @num_chipselect: chipselects are used to distinguish individual
- * SPI slaves, and are numbered from zero to num_chipselects.
- * each slave has a chipselect signal, but it's common that not
- * every chipselect is connected to a slave.
+ * SPI slaves, and are numbered from zero to num_chipselects.
+ * each slave has a chipselect signal, but it's common that not
+ * every chipselect is connected to a slave.
* @setup: updates the device mode and clocking records used by a
- * device's SPI controller; protocol code may call this.
+ * device's SPI controller; protocol code may call this.
* @transfer: adds a message to the controller's transfer queue.
* @cleanup: frees controller-specific state
*
struct spi_master {
struct class_device cdev;
- /* other than zero (== assign one dynamically), bus_num is fully
+ /* other than negative (== assign one dynamically), bus_num is fully
* board-specific. usually that simplifies to being SOC-specific.
- * example: one SOC has three SPI controllers, numbered 1..3,
+ * example: one SOC has three SPI controllers, numbered 0..2,
* and one board's schematics might show it using SPI-2. software
* would normally use bus_num=2 for that controller.
*/
- u16 bus_num;
+ s16 bus_num;
/* chipselects will be integral to many controllers; some others
* might use board-specific GPIOs.
* for this transfer. If 0 the default (from spi_device) is used.
* @cs_change: affects chipselect after this transfer completes
* @delay_usecs: microseconds to delay after this transfer before
- * (optionally) changing the chipselect status, then starting
- * the next transfer or completing this spi_message.
+ * (optionally) changing the chipselect status, then starting
+ * the next transfer or completing this spi_message.
* @transfer_list: transfers are sequenced through spi_message.transfers
*
* SPI transfers always write the same number of bytes as they read.
* and its transfers, ignore them until its completion callback.
*/
struct spi_message {
- struct list_head transfers;
+ struct list_head transfers;
struct spi_device *spi;
*/
/* completion is reported through a callback */
- void (*complete)(void *context);
+ void (*complete)(void *context);
void *context;
unsigned actual_length;
int status;
projects / linux-2.6-omap-h63xx.git / commitdiff