mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-27 05:23:34 +00:00
44ba6b0ecc
This feature provides for init of a single SPI port for the soft SPI feature. It is not really compatible with driver model since it assumes a single SPI port. Also, inserting SPI init into the driver by means of a #define is not very nice. This feature is not used by any active boards, so let's remove it. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
176 lines
3.8 KiB
C
176 lines
3.8 KiB
C
/*
|
|
* (C) Copyright 2002
|
|
* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
|
|
*
|
|
* Influenced by code from:
|
|
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <spi.h>
|
|
|
|
#include <malloc.h>
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Definitions
|
|
*/
|
|
|
|
#ifdef DEBUG_SPI
|
|
#define PRINTD(fmt,args...) printf (fmt ,##args)
|
|
#else
|
|
#define PRINTD(fmt,args...)
|
|
#endif
|
|
|
|
struct soft_spi_slave {
|
|
struct spi_slave slave;
|
|
unsigned int mode;
|
|
};
|
|
|
|
static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
|
|
{
|
|
return container_of(slave, struct soft_spi_slave, slave);
|
|
}
|
|
|
|
/*=====================================================================*/
|
|
/* Public Functions */
|
|
/*=====================================================================*/
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* Initialization
|
|
*/
|
|
void spi_init (void)
|
|
{
|
|
}
|
|
|
|
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
|
|
unsigned int max_hz, unsigned int mode)
|
|
{
|
|
struct soft_spi_slave *ss;
|
|
|
|
if (!spi_cs_is_valid(bus, cs))
|
|
return NULL;
|
|
|
|
ss = spi_alloc_slave(struct soft_spi_slave, bus, cs);
|
|
if (!ss)
|
|
return NULL;
|
|
|
|
ss->mode = mode;
|
|
|
|
/* TODO: Use max_hz to limit the SCK rate */
|
|
|
|
return &ss->slave;
|
|
}
|
|
|
|
void spi_free_slave(struct spi_slave *slave)
|
|
{
|
|
struct soft_spi_slave *ss = to_soft_spi(slave);
|
|
|
|
free(ss);
|
|
}
|
|
|
|
int spi_claim_bus(struct spi_slave *slave)
|
|
{
|
|
#ifdef CONFIG_SYS_IMMR
|
|
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
|
|
#endif
|
|
struct soft_spi_slave *ss = to_soft_spi(slave);
|
|
|
|
/*
|
|
* Make sure the SPI clock is in idle state as defined for
|
|
* this slave.
|
|
*/
|
|
if (ss->mode & SPI_CPOL)
|
|
SPI_SCL(1);
|
|
else
|
|
SPI_SCL(0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void spi_release_bus(struct spi_slave *slave)
|
|
{
|
|
/* Nothing to do */
|
|
}
|
|
|
|
/*-----------------------------------------------------------------------
|
|
* SPI transfer
|
|
*
|
|
* This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
|
|
* "bitlen" bits in the SPI MISO port. That's just the way SPI works.
|
|
*
|
|
* The source of the outgoing bits is the "dout" parameter and the
|
|
* destination of the input bits is the "din" parameter. Note that "dout"
|
|
* and "din" can point to the same memory location, in which case the
|
|
* input data overwrites the output data (since both are buffered by
|
|
* temporary variables, this is OK).
|
|
*/
|
|
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
|
|
const void *dout, void *din, unsigned long flags)
|
|
{
|
|
#ifdef CONFIG_SYS_IMMR
|
|
volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
|
|
#endif
|
|
struct soft_spi_slave *ss = to_soft_spi(slave);
|
|
uchar tmpdin = 0;
|
|
uchar tmpdout = 0;
|
|
const u8 *txd = dout;
|
|
u8 *rxd = din;
|
|
int cpol = ss->mode & SPI_CPOL;
|
|
int cpha = ss->mode & SPI_CPHA;
|
|
unsigned int j;
|
|
|
|
PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
|
|
slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen);
|
|
|
|
if (flags & SPI_XFER_BEGIN)
|
|
spi_cs_activate(slave);
|
|
|
|
for(j = 0; j < bitlen; j++) {
|
|
/*
|
|
* Check if it is time to work on a new byte.
|
|
*/
|
|
if ((j % 8) == 0) {
|
|
if (txd)
|
|
tmpdout = *txd++;
|
|
else
|
|
tmpdout = 0;
|
|
if(j != 0) {
|
|
if (rxd)
|
|
*rxd++ = tmpdin;
|
|
}
|
|
tmpdin = 0;
|
|
}
|
|
|
|
if (!cpha)
|
|
SPI_SCL(!cpol);
|
|
SPI_SDA(tmpdout & 0x80);
|
|
SPI_DELAY;
|
|
if (cpha)
|
|
SPI_SCL(!cpol);
|
|
else
|
|
SPI_SCL(cpol);
|
|
tmpdin <<= 1;
|
|
tmpdin |= SPI_READ;
|
|
tmpdout <<= 1;
|
|
SPI_DELAY;
|
|
if (cpha)
|
|
SPI_SCL(cpol);
|
|
}
|
|
/*
|
|
* If the number of bits isn't a multiple of 8, shift the last
|
|
* bits over to left-justify them. Then store the last byte
|
|
* read in.
|
|
*/
|
|
if (rxd) {
|
|
if ((bitlen % 8) != 0)
|
|
tmpdin <<= 8 - (bitlen % 8);
|
|
*rxd++ = tmpdin;
|
|
}
|
|
|
|
if (flags & SPI_XFER_END)
|
|
spi_cs_deactivate(slave);
|
|
|
|
return(0);
|
|
}
|