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Blackfin: bfin_spi: support gpios as chip selects

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Rather than only support the pins dedicated as chip selects, utilize the
gpio framework to support any gpio pin.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This commit is contained in:
Mike Frysinger 2010-06-02 06:13:50 -04:00
parent f3732edf46
commit 37a4b75d4c
2 changed files with 57 additions and 27 deletions
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83
drivers/spi/bfin_spi.c
View File

@ -13,6 +13,7 @@
#include <spi.h>
#include <asm/blackfin.h>
#include <asm/gpio.h>
#include <asm/portmux.h>
#include <asm/mach-common/bits/spi.h>
@ -34,48 +35,68 @@ MAKE_SPI_FUNC(SPI_BAUD, 0x14)
#define to_bfin_spi_slave(s) container_of(s, struct bfin_spi_slave, slave)
__attribute__((weak))
#define MAX_CTRL_CS 7
#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 defined(__ADSPBF538__) || defined(__ADSPBF539__)
/* The SPI1/SPI2 buses are weird ... only 1 CS */
if (bus > 0 && cs != 1)
return 0;
#endif
return (cs >= 1 && cs <= 7);
if (is_gpio_cs(cs))
return gpio_is_valid(gpio_cs(cs));
else
return (cs >= 1 && cs <= MAX_CTRL_CS);
}
__attribute__((weak))
void spi_cs_activate(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
write_SPI_FLG(bss,
(read_SPI_FLG(bss) &
~((!bss->flg << 8) << slave->cs)) |
(1 << slave->cs));
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();
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
}
__attribute__((weak))
void spi_cs_deactivate(struct spi_slave *slave)
{
struct bfin_spi_slave *bss = to_bfin_spi_slave(slave);
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));
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));
}
flg &= ~(1 << slave->cs);
write_SPI_FLG(bss, flg);
SSYNC();
debug("%s: SPI_FLG:%x\n", __func__, read_SPI_FLG(bss));
}
void spi_init()
@ -188,7 +209,13 @@ int spi_claim_bus(struct spi_slave *slave)
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
pins[slave->bus][0] = cs_pins[slave->bus][slave->cs - 1];
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);
@ -205,6 +232,8 @@ void spi_release_bus(struct 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();

1
include/configs/bfin_adi_common.h
View File

@ -254,6 +254,7 @@
/*
* Misc Settings
*/
#define CONFIG_BFIN_SPI_GPIO_CS /* Only matters if BFIN_SPI is enabled */
#define CONFIG_LZMA
#endif