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/*
* Driver for Blackfin On-Chip SPI device
*
* Copyright (c) 2005-2008 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
};
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct bfin_spi_slave *bss;
ulong sclk;
u32 mmr_base;
u32 baud;
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;
}
sclk = get_sclk();
baud = sclk / (2 * max_hz);
/* baud should be rounded up */
if (sclk % (2 * max_hz))
baud += 1;
if (baud < 2)
baud = 2;
else if (baud > (u16)-1)
baud = -1;
bss = malloc(sizeof(*bss));
if (!bss)
return NULL;
bss->slave.bus = bus;
bss->slave.cs = cs;
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->baud = baud;
bss->flg = mode & SPI_CS_HIGH ? 1 : 0;
debug("%s: bus:%i cs:%i mmr:%x ctl:%x baud:%i flg:%i\n", __func__,
bus, cs, mmr_base, bss->ctl, 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
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);
/* todo: take advantage of hardware fifos and setup RX dma */
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()) {
ret = -1;
goto done;
}
while (!(read_SPI_STAT(bss) & SPIF))
if (ctrlc()) {
ret = -1;
goto done;
}
while (!(read_SPI_STAT(bss) & RXS))
if (ctrlc()) {
ret = -1;
goto done;
}
value = read_SPI_RDBR(bss);
if (rx)
*rx++ = value;
debug("rx:%x\n", value);
}
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return ret;
}
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