/************************************************************************************
* configs/teensy/src/up_spi.c
* arch/arm/src/board/up_spi.c
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <debug.h>
#include <nuttx/spi.h>
#include <arch/board/board.h>
#include <avr/io.h>
#include "up_arch.h"
#include "chip.h"
#include "at90usb_internal.h"
#include "teensy_internal.h"
#ifdef CONFIG_AVR_SPI
/************************************************************************************
* Definitions
************************************************************************************/
/* Teensy SPI Connection
*
* -- ---- -- ------------------------- -------
* J2 NAME PIN NAME PAD
* -- ---- -- ------------------------- -------
* 1 VIN -- Connected to USB +RV
* 2 GND -- Connected to USB GND
* 3 3V3 -- Not used ---
* 4 NC -- Not used
* 5 CS 10 (SS/PCINT0) PB0 Pad B0
* 6 DI 12 (PDI/PCINT2/MOSI) PB2 Pad B2
* 7 SCK 11 (PCINT1/SCLK) PB1 Pad B1
* 8 DO 13 (PDO/PCINT3/MISO) PB3 Pad B3
* 9 IRQ -- Not used ---
* 10 CD 14 (PCINT4/OC.2A) PB4 Pad B4
* 11 WP 15 (PCINT5/OC.1A) PB5 Pad B5
* -- ---- -- ------------------------- -------
*/
#define TEENSY_CS (1 << 0)
#define TEENSY_CD (1 << 4)
#define TEENSY_WP (1 << 5)
/* The following enable debug output from this file (needs CONFIG_DEBUG too).
*
* CONFIG_SPI_DEBUG - Define to enable basic SSP debug
* CONFIG_SPI_VERBOSE - Define to enable verbose SSP debug
*/
#ifdef CONFIG_SPI_DEBUG
# define sspdbg lldbg
# ifdef CONFIG_SPI_VERBOSE
# define sspvdbg lldbg
# else
# define sspvdbg(x...)
# endif
#else
# undef CONFIG_SPI_VERBOSE
# define sspdbg(x...)
# define sspvdbg(x...)
#endif
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: at90usb_spiinitialize
*
* Description:
* Called to configure SPI chip select GPIO pins for the LPC1766-STK.
*
************************************************************************************/
void weak_function at90usb_spiinitialize(void)
{
/* The Teensy board has no dedicated SPI devices so we assume that SS is used
* for chip select:
*
* "When the SPI is configured as a Master (MSTR in SPCR is set), the user
* can determine the direction of the SS pin. If SS is configured as an
* output, the pin is a general output pin which does not affect the SPI
* system. ...
*
* "If SS is configured as an input, it must be held high to ensure Master
* SPI operation. If the SS pin is driven low by peripheral circuitry when
* the SPI is configured as a Master with the SS pin defined as an input,
* the SPI system interprets this as another master selecting the SPI ...
*/
DDRB |= TEENSY_CS; /* B0 is an output */
PORTB |= TEENSY_CS; /* Low de-selects */
DDRB &= ~(TEENSY_CD | TEENSY_WP); /* B4 and B5 are inputs */
PORTB |= (TEENSY_CD | TEENSY_WP); /* Pull high */
}
/************************************************************************************
* Name: avr_spiselect and avr_spistatus
*
* Description:
* The external functions, avr_spiselect and avr_spistatus must be provided by
* board-specific logic. They are implementations of the select and status 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 AVR logic.
* To use this common SPI logic on your board:
*
* 1. Provide logic in avr_sspinitialize() to configure SPI chip select pins.
* 2. Provide avr_spiselect() and avr_spistatus() functions in your board-specific
* logic. These functions will perform chip selection and status operations
* in the way your board is configured.
* 3. Add a calls to at90usb_spiinitialize() in your low level application
* initialization logic
* 4. The handle returned by up_spiinitialize() may then be used to bind the
* SPI driver to higher level logic (e.g., calling mmcsd_spislotinitialize(),
* for example, will bind the SPI driver to the SPI MMC/SD driver).
*
************************************************************************************/
void avr_spiselect(FAR struct spi_dev_s *dev, enum spi_dev_e devid, bool selected)
{
sspdbg("devid: %d CS: %s\n", (int)devid, selected ? "assert" : "de-assert");
/* Assert/de-assert the CS pin to the card */
if (selected)
{
PORTB &= ~TEENSY_CS;
}
else
{
PORTB |= TEENSY_CS;
}
}
uint8_t avr_spistatus(FAR struct spi_dev_s *dev, enum spi_dev_e devid)
{
uint8_t ret = 0;
uint8_t regval = PINB;
/* Both the CD and WP pins are pull high by the AT90USB and will be
* grounded it a card is inserted or write protected.
*/
if ((regval & TEENSY_CD) == 0)
{
ret |= SPI_STATUS_PRESENT;
}
if ((regval & TEENSY_WP) == 0)
{
ret |= SPI_STATUS_WRPROTECTED;
}
sspdbg("Returning %02x\n", ret);
return ret;
}
#endif /* CONFIG_AVR_SPI */
