sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

SAM3U: Add logic to bypass automated control of SPI chip selects

Browse Source 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4032 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2011-10-08 00:37:18 +00:00
parent 77c1f5402b
commit 11498e06a1
3 changed files with 107 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
configs/sam3u-ek/src/sam3uek_internal.h
View File

@ -164,9 +164,17 @@
/* SPI Chip Selects */
/* Chip select pin connected to the touchscreen controller and to ZigBee module connector. */
/* Chip select pin connected to the touchscreen controller and to the ZigBee module
* connector. Notice that the touchscreen chip select is implemented as a GPIO
* OUTPUT that must be controlled by board-specific. This is because the ADS7843E
* driver must be able to sample the device BUSY GPIO input between SPI transfers.
* However, the AD7843E will tri-state the BUSY input whenever the chip select is
* de-asserted. So the only option is to control the chip select manually and hold
* it low throughout the SPI transfer.
*/
#define GPIO_TSC_NPCS2 GPIO_SPI0_NPCS2_3
#define GPIO_TSC_NPCS2 (GPIO_OUTPUT|GPIO_CFG_PULLUP|GPIO_OUTPUT_SET|\
GPIO_PORT_PIOC|GPIO_PIN14)
/************************************************************************************
* Public Types

6
configs/sam3u-ek/src/up_lcd.c
View File

@ -798,9 +798,9 @@ static int sam3u_setpower(struct lcd_dev_s *dev, int power)
sam3u_gpiowrite(GPIO_LCD_BKL, false);
sam3u_gpiowrite(GPIO_LCD_BKL, false);
sam3u_gpiowrite(GPIO_LCD_BKL, false);
sam3u_gpiowrite(GPIO_LCD_BKL, true);;
sam3u_gpiowrite(GPIO_LCD_BKL, true);;
sam3u_gpiowrite(GPIO_LCD_BKL, true);;
sam3u_gpiowrite(GPIO_LCD_BKL, true);
sam3u_gpiowrite(GPIO_LCD_BKL, true);
sam3u_gpiowrite(GPIO_LCD_BKL, true);
}
/* This delay seems to be required... perhaps because of the big current jump? */

104
configs/sam3u-ek/src/up_spi.c
View File

@ -107,20 +107,29 @@ void weak_function sam3u_spiinitialize(void)
}
/****************************************************************************
* Name: sam3u_spiselect, sam3u_spistatus, and sam3u_spicmddata
* Name: sam3u_spicsnumber, sam3u_spiselect, sam3u_spistatus, and
* sam3u_spicmddata
*
* Description:
* These external functions must be provided by board-specific logic. They
* are implementations of the select, status, and cmddata methods of the SPI
* interface defined by struct spi_ops_s (see include/nuttx/spi.h). All
* other methods including up_spiinitialize()) are provided by common SAM3U
* logic. To use this common SPI logic on your board:
* include:
*
* o sam3u_spicsnumbe and sam3u_spiselect which are helper functions to
* manage the board-specific aspects of the unique SAM3U chip select
* architecture.
* o sam3u_spistatus and sam3u_spicmddata: Implementations of the status
* and cmddata methods of the SPI interface defined by struct spi_ops_
* (see include/nuttx/spi.h). All other methods including
* up_spiinitialize()) are provided by common SAM3U logic.
*
* To use this common SPI logic on your board:
*
* 1. Provide logic in sam3u_boardinitialize() to configure SPI chip select
* pins.
* 2. Provide sam3u_spiselect() and sam3u_spistatus() functions in your
* board-specific logic. These functions will perform chip selection
* and status operations using GPIOs in the way your board is configured.
* 2. Provide sam3u_spicsnumber(), sam3u_spiselect() and sam3u_spistatus()
* functions in your board-specific logic. These functions will perform
* chip selection and status operations using GPIOs in the way your board
* is configured.
* 2. If CONFIG_SPI_CMDDATA is defined in the NuttX configuration, provide
* sam3u_spicmddata() functions in your board-specific logic. This
* function will perform cmd/data selection operations using GPIOs in
@ -134,8 +143,26 @@ void weak_function sam3u_spiinitialize(void)
*
****************************************************************************/
/****************************************************************************
* Name: sam3u_spicsnumber
*
* Description:
* The SAM3U has 4 CS registers for controlling device features. This
* function must be provided by board-specific code. Given a logical device
* ID, this function returns a number from 0 to 3 that identifies one of
* these SAM3U CS resources.
*
* Input Parameters:
* devid - Identifies the (logical) device
*
* Returned Values:
* On success, a CS number from 0 to 3 is returned; A negated errno may
* be returned on a failure.
*
****************************************************************************/
#ifdef CONFIG_SAM3U_SPI
int sam3u_spiselect(enum spi_dev_e devid)
int sam3u_spicsnumber(enum spi_dev_e devid)
{
int cs = -EINVAL;
@ -144,7 +171,7 @@ int sam3u_spiselect(enum spi_dev_e devid)
{
/* Assert the CS pin to the OLED display */
cs = 2;
cs = 2;
}
#endif
@ -152,6 +179,63 @@ int sam3u_spiselect(enum spi_dev_e devid)
return cs;
}
/****************************************************************************
* Name: sam3u_spiselect
*
* Description:
* PIO chip select pins may be programmed by the board specific logic in
* one of two different ways. First, the pins may be programmed as SPI
* peripherals. In that case, the pins are completely controlled by the
* SPI driver. This method still needs to be provided, but it may be only
* a stub.
*
* An alternative way to program the PIO chip select pins is as a normal
* GPIO output. In that case, the automatic control of the CS pins is
* bypassed and this function must provide control of the chip select.
* NOTE: In this case, the GPIO output pin does *not* have to be the
* same as the NPCS pin normal associated with the chip select number.
*
* Input Parameters:
* devid - Identifies the (logical) device
* selected - TRUE:Select the device, FALSE:De-select the device
*
* Returned Values:
* None
*
****************************************************************************/
void sam3u_spiselect(enum spi_dev_e devid, bool selected)
{
/* The touchscreen chip select is implemented as a GPIO OUTPUT that must
* be controlled by this function. This is because the ADS7843E driver
* must be able to sample the device BUSY GPIO input between SPI transfers.
* However, the AD7843E will tri-state the BUSY input whenever the chip
* select is de-asserted. So the only option is to control the chip select
* manually and hold it low throughout the SPI transfer.
*/
#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_ADS7843E)
if (devid == SPIDEV_TOUCHSCREEN)
{
sam3u_gpiowrite(GPIO_TSC_NPCS2, !selected);
}
#endif
}
/****************************************************************************
* Name: sam3u_spistatus
*
* Description:
* Return status information associated with the SPI device.
*
* Input Parameters:
* devid - Identifies the (logical) device
*
* Returned Values:
* Bit-encoded SPI status (see include/nuttx/spi.h.
*
****************************************************************************/
uint8_t sam3u_spistatus(FAR struct spi_dev_s *dev, enum spi_dev_e devid)
{
return 0;