u-boot/drivers/spi/bfin_spi.c
Scott Jiang d4d4f90377 bfin: discard invalid data and clear RXS in bf5xx spi driver
There may be dirty data in RDBR, so we should discard invalid data.
This operation also clears RXS bit in STAT register.

Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
2013-05-13 16:26:27 +08:00

308 lines
6.8 KiB
C

/*
* Driver for Blackfin On-Chip SPI device
*
* Copyright (c) 2005-2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
/*#define DEBUG*/
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/blackfin.h>
#include <asm/gpio.h>
#include <asm/portmux.h>
#include <asm/mach-common/bits/spi.h>
struct bfin_spi_slave {
struct spi_slave slave;
void *mmr_base;
u16 ctl, baud, flg;
};
#define MAKE_SPI_FUNC(mmr, off) \
static inline void write_##mmr(struct bfin_spi_slave *bss, u16 val) { bfin_write16(bss->mmr_base + off, val); } \
static inline u16 read_##mmr(struct bfin_spi_slave *bss) { return bfin_read16(bss->mmr_base + off); }
MAKE_SPI_FUNC(SPI_CTL, 0x00)
MAKE_SPI_FUNC(SPI_FLG, 0x04)
MAKE_SPI_FUNC(SPI_STAT, 0x08)
MAKE_SPI_FUNC(SPI_TDBR, 0x0c)
MAKE_SPI_FUNC(SPI_RDBR, 0x10)
MAKE_SPI_FUNC(SPI_BAUD, 0x14)
#define to_bfin_spi_slave(s) container_of(s, struct bfin_spi_slave, slave)
#define gpio_cs(cs) ((cs) - MAX_CTRL_CS)
#ifdef CONFIG_BFIN_SPI_GPIO_CS
# define is_gpio_cs(cs) ((cs) > MAX_CTRL_CS)
#else
# define is_gpio_cs(cs) 0
#endif
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
if (is_gpio_cs(cs))
return gpio_is_valid(gpio_cs(cs));
else
return (cs >= 1 && cs <= MAX_CTRL_CS);
}
void spi_cs_activate(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
if (is_gpio_cs(slave->cs)) {
unsigned int cs = gpio_cs(slave->cs);
gpio_set_value(cs, bss->flg);
debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
} else {
write_SPI_FLG(bss,
(read_SPI_FLG(bss) &
~((!bss->flg << 8) << slave->cs)) |
(1 << slave->cs));
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
}
SSYNC();
}
void spi_cs_deactivate(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
if (is_gpio_cs(slave->cs)) {
unsigned int cs = gpio_cs(slave->cs);
gpio_set_value(cs, !bss->flg);
debug("%s: SPI_CS_GPIO:%x\n", __func__, gpio_get_value(cs));
} else {
u16 flg;
/* make sure we force the cs to deassert rather than let the
* pin float back up. otherwise, exact timings may not be
* met some of the time leading to random behavior (ugh).
*/
flg = read_SPI_FLG(bss) | ((!bss->flg << 8) << slave->cs);
write_SPI_FLG(bss, flg);
SSYNC();
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
flg &= ~(1 << slave->cs);
write_SPI_FLG(bss, flg);
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
}
SSYNC();
}
void spi_init()
{
}
#ifdef SPI_CTL
# define SPI0_CTL SPI_CTL
#endif
#define SPI_PINS(n) \
[n] = { 0, P_SPI##n##_SCK, P_SPI##n##_MISO, P_SPI##n##_MOSI, 0 }
static unsigned short pins[][5] = {
#ifdef SPI0_CTL
SPI_PINS(0),
#endif
#ifdef SPI1_CTL
SPI_PINS(1),
#endif
#ifdef SPI2_CTL
SPI_PINS(2),
#endif
};
#define SPI_CS_PINS(n) \
[n] = { \
P_SPI##n##_SSEL1, P_SPI##n##_SSEL2, P_SPI##n##_SSEL3, \
P_SPI##n##_SSEL4, P_SPI##n##_SSEL5, P_SPI##n##_SSEL6, \
P_SPI##n##_SSEL7, \
}
static const unsigned short cs_pins[][7] = {
#ifdef SPI0_CTL
SPI_CS_PINS(0),
#endif
#ifdef SPI1_CTL
SPI_CS_PINS(1),
#endif
#ifdef SPI2_CTL
SPI_CS_PINS(2),
#endif
};
void spi_set_speed(struct spi_slave *slave, uint hz)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
ulong sclk;
u32 baud;
sclk = get_sclk();
baud = sclk / (2 * hz);
/* baud should be rounded up */
if (sclk % (2 * hz))
baud += 1;
if (baud < 2)
baud = 2;
else if (baud > (u16)-1)
baud = -1;
bss->baud = baud;
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct bfin_spi_slave *bss;
u32 mmr_base;
if (!spi_cs_is_valid(bus, cs))
return NULL;
if (bus >= ARRAY_SIZE(pins) || pins[bus] == NULL) {
debug("%s: invalid bus %u\n", __func__, bus);
return NULL;
}
switch (bus) {
#ifdef SPI0_CTL
case 0: mmr_base = SPI0_CTL; break;
#endif
#ifdef SPI1_CTL
case 1: mmr_base = SPI1_CTL; break;
#endif
#ifdef SPI2_CTL
case 2: mmr_base = SPI2_CTL; break;
#endif
default: return NULL;
}
bss = spi_alloc_slave(struct bfin_spi_slave, bus, cs);
if (!bss)
return NULL;
bss->mmr_base = (void *)mmr_base;
bss->ctl = SPE | MSTR | TDBR_CORE;
if (mode & SPI_CPHA) bss->ctl |= CPHA;
if (mode & SPI_CPOL) bss->ctl |= CPOL;
if (mode & SPI_LSB_FIRST) bss->ctl |= LSBF;
bss->flg = mode & SPI_CS_HIGH ? 1 : 0;
spi_set_speed(&bss->slave, max_hz);
debug("%s: bus:%i cs:%i mmr:%x ctl:%x baud:%i flg:%i\n", __func__,
bus, cs, mmr_base, bss->ctl, bss->baud, bss->flg);
return &bss->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
free(bss);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
if (is_gpio_cs(slave->cs)) {
unsigned int cs = gpio_cs(slave->cs);
gpio_request(cs, "bfin-spi");
gpio_direction_output(cs, !bss->flg);
pins[slave->bus][0] = P_DONTCARE;
} else
pins[slave->bus][0] = cs_pins[slave->bus][slave->cs - 1];
peripheral_request_list(pins[slave->bus], "bfin-spi");
write_SPI_CTL(bss, bss->ctl);
write_SPI_BAUD(bss, bss->baud);
SSYNC();
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
peripheral_free_list(pins[slave->bus]);
if (is_gpio_cs(slave->cs))
gpio_free(gpio_cs(slave->cs));
write_SPI_CTL(bss, 0);
SSYNC();
}
#ifndef CONFIG_BFIN_SPI_IDLE_VAL
# define CONFIG_BFIN_SPI_IDLE_VAL 0xff
#endif
static int spi_pio_xfer(struct bfin_spi_slave *bss, const u8 *tx, u8 *rx,
uint bytes)
{
/* discard invalid data and clear RXS */
read_SPI_RDBR(bss);
/* todo: take advantage of hardware fifos */
while (bytes--) {
u8 value = (tx ? *tx++ : CONFIG_BFIN_SPI_IDLE_VAL);
debug("%s: tx:%x ", __func__, value);
write_SPI_TDBR(bss, value);
SSYNC();
while ((read_SPI_STAT(bss) & TXS))
if (ctrlc())
return -1;
while (!(read_SPI_STAT(bss) & SPIF))
if (ctrlc())
return -1;
while (!(read_SPI_STAT(bss) & RXS))
if (ctrlc())
return -1;
value = read_SPI_RDBR(bss);
if (rx)
*rx++ = value;
debug("rx:%x\n", value);
}
return 0;
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
const u8 *tx = dout;
u8 *rx = din;
uint bytes = bitlen / 8;
int ret = 0;
debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
slave->bus, slave->cs, bitlen, bytes, flags);
if (bitlen == 0)
goto done;
/* we can only do 8 bit transfers */
if (bitlen % 8) {
flags |= SPI_XFER_END;
goto done;
}
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
ret = spi_pio_xfer(bss, tx, rx, bytes);
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return ret;
}