/****************************************************************************
* config/mcu123-lpc214x/src/up_spi.c
*
* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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.
*
****************************************************************************/
/****************************************************************************
* One the mcu123.com lpc214x board, the MMC slot is connect via SPI with the
* following SPI mode pinout:
*
* 1 CS: Chip select (low) - SSEL1 5 SCLK: Clock - SCK1
* 2 DI: Data input - MOSI1 6 Vss2: Supply Voltage- GRND
* 3 Vss: Supply Voltage - GRND 7 DO: Data Output - MISO1
* 4 Vdd: Power Supply - Vcc 8 - N/C
*
* The LPC214x supports one SPI port (SPI0) and one SSP port (SPI1). SPI1
* is used to interface with the MMC connect
*
* SCK1 - pin 47, P0.17/CAP1.2/SCK1/MAT1.2
* MISO1 - pin 53, P0.18/CAP1.3/MISO1/MAT1.3
* MOSI1 - pin 54, P0.19/MAT1.2/MOSI1/CAP1.2
* SSEL1 - pin 55, P0.20/MAT1.3/SSEL1/EINT3
*
* SPI0 is available on the mcu123.com board (pins 27, 29, 30, and 31).
* Pin 27 is dedicated to a chip select, pins 30 and 31 connect to keys, nd
* pin 29 is unconnected.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/spi.h>
#include <arch/board/board.h>
#include <nuttx/arch.h>
#include <nuttx/spi.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chip.h"
#include "lpc214x_power.h"
#include "lpc214x_pinsel.h"
#include "lpc214x_spi.h"
/****************************************************************************
* Definitions
****************************************************************************/
#define LPC214X_CCLKFREQ (LPC214X_FOSC*LPC214X_PLL_M)
#define LPC214X_PCLKFREQ (LPC214X_CCLKFREQ/LPC214X_APB_DIV)
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void spi_select(FAR struct spi_dev_s *dev, enum spi_dev_e devid, boolean selected);
static uint32 spi_setfrequency(FAR struct spi_dev_s *dev, uint32 frequency);
static ubyte spi_status(FAR struct spi_dev_s *dev, enum spi_dev_e devid);
static uint16 spi_send(FAR struct spi_dev_s *dev, uint16 ch);
static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer, size_t nwords);
static void spi_recvblock(FAR struct spi_dev_s *dev, FAR void *buffer, size_t nwords);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct spi_ops_s g_spiops =
{
.select = spi_select,
.setfrequency = spi_setfrequency,
.status = spi_status,
.send = spi_send,
.sndblock = spi_sndblock,
.recvblock = spi_recvblock,
};
static struct spi_dev_s g_spidev = { &g_spiops };
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: spi_select
*
* Description:
* Enable/disable the SPI slave select. The implementation of this method
* must include handshaking: If a device is selected, it must hold off
* all other attempts to select the device until the device is deselecte.
*
* Input Parameters:
* dev - Device-specific state data
* devid - Identifies the device to select
* selected - TRUE: slave selected, FALSE: slave de-selected
*
* Returned Value:
* None
*
****************************************************************************/
static void spi_select(FAR struct spi_dev_s *dev, enum spi_dev_e devid, boolean selected)
{
uint32 bit = 1 << 20;
if (selected)
{
/* Enable slave select (low enables) */
putreg32(bit, LPC214X_GPIO0_BASE+LPC214X_GPIO_CLR_OFFSET);
}
else
{
/* Disable slave select (low enables) */
putreg32(bit, LPC214X_GPIO0_BASE+LPC214X_GPIO_SET_OFFSET);
/* Wait for the TX FIFO not full indication */
while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF));
putreg16(0xff, LPC214X_SPI1_DR);
/* Wait until TX FIFO and TX shift buffer are empty */
while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_BSY);
/* Wait until RX FIFO is not empty */
while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE));
/* Then read and discard bytes until the RX FIFO is empty */
do
{
(void)getreg16(LPC214X_SPI1_DR);
}
while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE);
}
}
/****************************************************************************
* Name: spi_setfrequency
*
* Description:
* Set the SPI frequency.
*
* Input Parameters:
* dev - Device-specific state data
* frequency - The SPI frequency requested
*
* Returned Value:
* Returns the actual frequency selected
*
****************************************************************************/
static uint32 spi_setfrequency(FAR struct spi_dev_s *dev, uint32 frequency)
{
uint32 divisor = LPC214X_PCLKFREQ / frequency;
if (divisor < 2)
{
divisor = 2;
}
else if (divisor > 254)
{
divisor = 254;
}
divisor = (divisor + 1) & ~1;
putreg8(divisor, LPC214X_SPI1_CPSR);
return LPC214X_PCLKFREQ / divisor;
}
/****************************************************************************
* Name: spi_status
*
* Description:
* Get SPI/MMC status
*
* Input Parameters:
* dev - Device-specific state data
* devid - Identifies the device to report status on
*
* Returned Value:
* Returns a bitset of status values (see SPI_STATUS_* defines
*
****************************************************************************/
static ubyte spi_status(FAR struct spi_dev_s *dev, enum spi_dev_e devid)
{
/* I don't think there is anyway to determine these things on the mcu123.com
* board.
*/
return SPI_STATUS_PRESENT;
}
/****************************************************************************
* Name: spi_send
*
* Description:
* Exchange one word on SPI
*
* Input Parameters:
* dev - Device-specific state data
* wd - The word to send. the size of the data is determined by the
* number of bits selected for the SPI interface.
*
* Returned Value:
* response
*
****************************************************************************/
static uint16 spi_send(FAR struct spi_dev_s *dev, uint16 wd)
{
/* Wait while the TX FIFO is full */
while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF));
/* Write the byte to the TX FIFO */
putreg16((ubyte)wd, LPC214X_SPI1_DR);
/* Wait for the RX FIFO not empty */
while (!(getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE));
/* Get the value from the RX FIFO and return it */
return (uint16)getreg16(LPC214X_SPI1_DR);
}
/*************************************************************************
* Name: spi_sndblock
*
* Description:
* Send a block of data on SPI
*
* Input Parameters:
* dev - Device-specific state data
* buffer - A pointer to the buffer of data to be sent
* nwords - the length of data to send from the buffer in number of words.
* The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into ubytes; if nbits >8, the data is packed into uint16's
*
* Returned Value:
* None
*
****************************************************************************/
static void spi_sndblock(FAR struct spi_dev_s *dev, FAR const void *buffer, size_t nwords)
{
FAR const ubyte *ptr = (FAR const ubyte *)buffer;
ubyte sr;
/* Loop while thre are bytes remaining to be sent */
while (nwords > 0)
{
/* While the TX FIFO is not full and there are bytes left to send */
while ((getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF) && nwords)
{
/* Send the data */
putreg16((uint16)*ptr, LPC214X_SPI1_DR);
ptr++;
nwords--;
}
}
/* Then discard all card responses until the RX & TX FIFOs are emptied. */
do
{
/* Is there anything in the RX fifo? */
sr = getreg8(LPC214X_SPI1_SR);
if ((sr & LPC214X_SPI1SR_RNE) != 0)
{
/* Yes.. Read and discard */
(void)getreg16(LPC214X_SPI1_DR);
}
/* There is a race condition where TFE may go TRUE just before
* RNE goes true and this loop terminates prematurely. The nasty little
* delay in the following solves that (it could probably be tuned
* to improve performance).
*/
else if ((sr & LPC214X_SPI1SR_TFE) != 0)
{
up_udelay(100);
sr = getreg8(LPC214X_SPI1_SR);
}
}
while ((sr & LPC214X_SPI1SR_RNE) != 0 || (sr & LPC214X_SPI1SR_TFE) == 0);
}
/****************************************************************************
* Name: spi_recvblock
*
* Description:
* Revice a block of data from SPI
*
* Input Parameters:
* dev - Device-specific state data
* buffer - A pointer to the buffer in which to recieve data
* nwords - the length of data that can be received in the buffer in number
* of words. The wordsize is determined by the number of bits-per-word
* selected for the SPI interface. If nbits <= 8, the data is
* packed into ubytes; if nbits >8, the data is packed into uint16's
*
* Returned Value:
* None
*
****************************************************************************/
static void spi_recvblock(FAR struct spi_dev_s *dev, FAR void *buffer, size_t nwords)
{
FAR ubyte *ptr = (FAR ubyte*)buffer;
uint32 fifobytes = 0;
/* While there is remaining to be sent (and no synchronization error has occurred) */
while (ptr || fifobytes)
{
/* Fill the transmit FIFO with 0xff...
* Write 0xff to the data register while (1) the TX FIFO is
* not full, (2) we have not exceeded the depth of the TX FIFO,
* and (3) there are more bytes to be sent.
*/
while ((getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_TNF) &&
(fifobytes < LPC214X_SPI1_FIFOSZ) && nwords)
{
putreg16(0xff, LPC214X_SPI1_DR);
nwords--;
fifobytes++;
}
/* Now, read the RX data from the RX FIFO while the RX FIFO is not empty */
while (getreg8(LPC214X_SPI1_SR) & LPC214X_SPI1SR_RNE)
{
*ptr++ = (ubyte)getreg16(LPC214X_SPI1_DR);
fifobytes--;
}
}
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_spiinitialize
*
* Description:
* Initialize the selected SPI port
*
* Input Parameter:
* Port number (for hardware that has mutiple SPI interfaces)
*
* Returned Value:
* Valid SPI device structre reference on succcess; a NULL on failure
*
****************************************************************************/
FAR struct spi_dev_s *up_spiinitialize(int port)
{
uint32 regval32;
ubyte regval8;
int i;
/* Only the SPI1 interface is supported */
#ifdef CONFIG_DEBUG
if (port != 1)
{
return NULL;
}
#endif
/* Configure multiplexed pins as connected on the mcu123.com board:
*
* PINSEL1 P0.17/CAP1.2/SCK1/MAT1.2 Bits 2-3=10 for SCK1
* PINSEL1 P0.18/CAP1.3/MISO1/MAT1.3 Bits 4-5=10 for MISO1
* PINSEL1 P0.19/MAT1.2/MOSI1/CAP1.2 Bits 6-7=10 for MOSI1
* PINSEL1 P0.20/MAT1.3/SSEL1/EINT3 Bits 8-9=10 for P0.20 (we'll control it via GPIO)
*/
regval32 = getreg32(LPC214X_PINSEL1);
regval32 &= ~(LPC214X_PINSEL1_P017_MASK|LPC214X_PINSEL1_P018_MASK|
LPC214X_PINSEL1_P019_MASK|LPC214X_PINSEL1_P020_MASK);
regval32 |= (LPC214X_PINSEL1_P017_SCK1|LPC214X_PINSEL1_P018_MISO1|
LPC214X_PINSEL1_P019_MOSI1|LPC214X_PINSEL1_P020_GPIO);
putreg32(regval32, LPC214X_PINSEL1);
/* Disable chip select using P0.20 (SSEL1) (low enables) */
regval32 = 1 << 20;
putreg32(regval32, LPC214X_GPIO0_BASE+LPC214X_GPIO_SET_OFFSET);
regval32 |= getreg32(LPC214X_GPIO0_BASE+LPC214X_GPIO_DIR_OFFSET);
putreg32(regval32, LPC214X_GPIO0_BASE+LPC214X_GPIO_DIR_OFFSET);
/* Enable peripheral clocking to SPI1 */
regval32 = getreg32(LPC214X_PCON_PCONP);
regval32 |= LPC214X_PCONP_PCSPI1;
putreg32(regval32, LPC214X_PCON_PCONP);
/* Configure 8-bit SPI mode */
putreg16(LPC214X_SPI1CR0_DSS8BIT|LPC214X_SPI1CR0_FRFSPI, LPC214X_SPI1_CR0);
/* Disable the SSP and all interrupts (we'll poll for all data) */
putreg8(0, LPC214X_SPI1_CR1);
putreg8(0, LPC214X_SPI1_IMSC);
/* Set the initial clock frequency for indentification mode < 400kHz */
spi_setfrequency(NULL, 400000);
/* Enable the SPI */
regval8 = getreg8(LPC214X_SPI1_CR1);
putreg8(regval8 | LPC214X_SPI1CR1_SSE, LPC214X_SPI1_CR1);
for (i = 0; i < 8; i++)
{
(void)getreg16(LPC214X_SPI1_DR);
}
return &g_spidev;
}