From 4cff33f94fefcce1b3c01a9d1da6bb85fe3cbdfa Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Fri, 17 Feb 2006 10:02:18 -0800 Subject: [PATCH] SPI: per-transfer overrides for wordsize and clocking Some protocols (like one for some bitmap displays) require different clock speed or word size settings for each transfer in an SPI message. This adds those parameters to struct spi_transfer. They are to be used when they are nonzero; otherwise the defaults from spi_device are to be used. The patch also adds a setup_transfer callback to spi_bitbang, uses it for messages that use those overrides, and implements it so that the pure bitbanging code can help resolve any questions about how it should work. Signed-off-by: Imre Deak Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- include/linux/spi/spi.h | 8 ++++++++ include/linux/spi/spi_bitbang.h | 6 ++++++ 2 files changed, 14 insertions(+) (limited to 'include') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index b05f146..caa4665 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -31,6 +31,7 @@ extern struct bus_type spi_bus_type; * @master: SPI controller used with the device. * @max_speed_hz: Maximum clock rate to be used with this chip * (on this board); may be changed by the device's driver. + * The spi_transfer.speed_hz can override this for each 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. @@ -38,6 +39,7 @@ extern struct bus_type spi_bus_type; * 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. + * 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. * @controller_state: Controller's runtime state @@ -268,6 +270,10 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); * @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 * @len: size of rx and tx buffers (in bytes) + * @speed_hz: Select a speed other then the device default for this + * transfer. If 0 the default (from spi_device) is used. + * @bits_per_word: select a bits_per_word other then the device default + * 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 @@ -322,7 +328,9 @@ struct spi_transfer { dma_addr_t rx_dma; unsigned cs_change:1; + u8 bits_per_word; u16 delay_usecs; + u32 speed_hz; struct list_head transfer_list; }; diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h index c961fe9..c954557 100644 --- a/include/linux/spi/spi_bitbang.h +++ b/include/linux/spi/spi_bitbang.h @@ -30,6 +30,12 @@ struct spi_bitbang { struct spi_master *master; + /* setup_transfer() changes clock and/or wordsize to match settings + * for this transfer; zeroes restore defaults from spi_device. + */ + int (*setup_transfer)(struct spi_device *spi, + struct spi_transfer *t); + void (*chipselect)(struct spi_device *spi, int is_on); #define BITBANG_CS_ACTIVE 1 /* normally nCS, active low */ #define BITBANG_CS_INACTIVE 0 -- cgit v1.1 From e0c9905e87ac1bc56c9ea8f5b2934aeee53dce26 Mon Sep 17 00:00:00 2001 From: Stephen Street Date: Tue, 7 Mar 2006 23:53:24 -0800 Subject: [PATCH] SPI: add PXA2xx SSP SPI Driver This driver turns a PXA2xx synchronous serial port (SSP) into a SPI master controller (see Documentation/spi/spi_summary). The driver has the following features: - Support for any PXA2xx SSP - SSP PIO and SSP DMA data transfers. - External and Internal (SSPFRM) chip selects. - Per slave device (chip) configuration. - Full suspend, freeze, resume support. Signed-off-by: Stephen Street Signed-off-by: Andrew Morton Cc: David Brownell Signed-off-by: Greg Kroah-Hartman --- include/asm-arm/arch-pxa/pxa2xx_spi.h | 68 +++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 include/asm-arm/arch-pxa/pxa2xx_spi.h (limited to 'include') diff --git a/include/asm-arm/arch-pxa/pxa2xx_spi.h b/include/asm-arm/arch-pxa/pxa2xx_spi.h new file mode 100644 index 0000000..1e70908 --- /dev/null +++ b/include/asm-arm/arch-pxa/pxa2xx_spi.h @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef PXA2XX_SPI_H_ +#define PXA2XX_SPI_H_ + +#define PXA2XX_CS_ASSERT (0x01) +#define PXA2XX_CS_DEASSERT (0x02) + +#if defined(CONFIG_PXA25x) +#define CLOCK_SPEED_HZ 3686400 +#define SSP1_SerClkDiv(x) (((CLOCK_SPEED_HZ/2/(x+1))<<8)&0x0000ff00) +#define SSP2_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00) +#define SSP3_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00) +#elif defined(CONFIG_PXA27x) +#define CLOCK_SPEED_HZ 13000000 +#define SSP1_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00) +#define SSP2_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00) +#define SSP3_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00) +#endif + +#define SSP1_VIRT ((void *)(io_p2v(__PREG(SSCR0_P(1))))) +#define SSP2_VIRT ((void *)(io_p2v(__PREG(SSCR0_P(2))))) +#define SSP3_VIRT ((void *)(io_p2v(__PREG(SSCR0_P(3))))) + +enum pxa_ssp_type { + SSP_UNDEFINED = 0, + PXA25x_SSP, /* pxa 210, 250, 255, 26x */ + PXA25x_NSSP, /* pxa 255, 26x (including ASSP) */ + PXA27x_SSP, +}; + +/* device.platform_data for SSP controller devices */ +struct pxa2xx_spi_master { + enum pxa_ssp_type ssp_type; + u32 clock_enable; + u16 num_chipselect; + u8 enable_dma; +}; + +/* spi_board_info.controller_data for SPI slave devices, + * copied to spi_device.platform_data ... mostly for dma tuning + */ +struct pxa2xx_spi_chip { + u8 tx_threshold; + u8 rx_threshold; + u8 dma_burst_size; + u32 timeout_microsecs; + u8 enable_loopback; + void (*cs_control)(u32 command); +}; + +#endif /*PXA2XX_SPI_H_*/ -- cgit v1.1 From 747d844ee9a183ff3067bb1181f2a25c50649538 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Sun, 2 Apr 2006 10:33:37 -0800 Subject: [PATCH] SPI: spi whitespace fixes This removes superfluous whitespace in the header. Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- include/linux/spi/spi.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'include') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index caa4665..0820067 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -36,15 +36,15 @@ extern struct bus_type spi_bus_type; * @mode: The spi mode defines how data is clocked out and in. * This may be changed by the device's driver. * @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. * 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. @@ -145,13 +145,13 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * 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 * @@ -276,8 +276,8 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); * 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. @@ -364,7 +364,7 @@ struct spi_transfer { * and its transfers, ignore them until its completion callback. */ struct spi_message { - struct list_head transfers; + struct list_head transfers; struct spi_device *spi; @@ -382,7 +382,7 @@ struct spi_message { */ /* completion is reported through a callback */ - void (*complete)(void *context); + void (*complete)(void *context); void *context; unsigned actual_length; int status; -- cgit v1.1 From ff9f4771b5f017ee0f57629488b6cd7a6ef3d19b Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Sun, 2 Apr 2006 16:06:35 -0500 Subject: [PATCH] SPI: Renamed bitbang_transfer_setup to spi_bitbang_setup_transfer and export it Renamed bitbang_transfer_setup to follow convention of other exported symbols from spi-bitbang. Exported spi_bitbang_setup_transfer to allow users of spi-bitbang to use the function in their own setup_transfer. Signed-off-by: Kumar Gala Cc: David Brownell Signed-off-by: Greg Kroah-Hartman --- include/linux/spi/spi_bitbang.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h index c954557..16ce178 100644 --- a/include/linux/spi/spi_bitbang.h +++ b/include/linux/spi/spi_bitbang.h @@ -57,6 +57,8 @@ struct spi_bitbang { extern int spi_bitbang_setup(struct spi_device *spi); extern void spi_bitbang_cleanup(const struct spi_device *spi); extern int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m); +extern int spi_bitbang_setup_transfer(struct spi_device *spi, + struct spi_transfer *t); /* start or stop queue processing */ extern int spi_bitbang_start(struct spi_bitbang *spi); -- cgit v1.1 From ccf77cc4af5b048e20cfd9327fcc286cb69c34cc Mon Sep 17 00:00:00 2001 From: David Brownell Date: Mon, 3 Apr 2006 15:46:22 -0700 Subject: [PATCH] SPI: devices can require LSB-first encodings Add spi_device hook for LSB-first word encoding, and update all the (in-tree) controller drivers to reject such devices. Eventually, some controller drivers will be updated to support lsb-first encodings on the wire; no current drivers need this. Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- include/linux/spi/spi.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 0820067..77add90 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -35,10 +35,13 @@ extern struct bus_type spi_bus_type; * @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 * 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. @@ -67,6 +70,7 @@ struct spi_device { #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; @@ -75,7 +79,6 @@ struct spi_device { // 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 -- cgit v1.1 From a020ed7521a9737bcf3e34eb880867c60c3c68d0 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Mon, 3 Apr 2006 15:49:04 -0700 Subject: [PATCH] SPI: busnum == 0 needs to work We need to be able to have a "SPI bus 0" matching chip numbering; but that number was wrongly used to flag dynamic allocation of a bus number. This patch resolves that issue; now negative numbers trigger dynamic alloc. It also updates the how-to-write-a-controller-driver overview to mention this stuff. Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- include/linux/spi/spi.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 77add90..e928c0d 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -172,13 +172,13 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) 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. -- cgit v1.1