altera_spi.c
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/*
* Altera SPI driver
*
* based on bfin_spi.c
* Copyright (c) 2005-2008 Analog Devices Inc.
* Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/io.h>
#include <malloc.h>
#include <spi.h>
#define ALTERA_SPI_RXDATA 0
#define ALTERA_SPI_TXDATA 4
#define ALTERA_SPI_STATUS 8
#define ALTERA_SPI_CONTROL 12
#define ALTERA_SPI_SLAVE_SEL 20
#define ALTERA_SPI_STATUS_ROE_MSK (0x8)
#define ALTERA_SPI_STATUS_TOE_MSK (0x10)
#define ALTERA_SPI_STATUS_TMT_MSK (0x20)
#define ALTERA_SPI_STATUS_TRDY_MSK (0x40)
#define ALTERA_SPI_STATUS_RRDY_MSK (0x80)
#define ALTERA_SPI_STATUS_E_MSK (0x100)
#define ALTERA_SPI_CONTROL_IROE_MSK (0x8)
#define ALTERA_SPI_CONTROL_ITOE_MSK (0x10)
#define ALTERA_SPI_CONTROL_ITRDY_MSK (0x40)
#define ALTERA_SPI_CONTROL_IRRDY_MSK (0x80)
#define ALTERA_SPI_CONTROL_IE_MSK (0x100)
#define ALTERA_SPI_CONTROL_SSO_MSK (0x400)
#ifndef CONFIG_SYS_ALTERA_SPI_LIST
#define CONFIG_SYS_ALTERA_SPI_LIST { CONFIG_SYS_SPI_BASE }
#endif
static ulong altera_spi_base_list[] = CONFIG_SYS_ALTERA_SPI_LIST;
struct altera_spi_slave {
struct spi_slave slave;
ulong base;
};
#define to_altera_spi_slave(s) container_of(s, struct altera_spi_slave, slave)
__attribute__((weak))
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return bus < ARRAY_SIZE(altera_spi_base_list) && cs < 32;
}
__attribute__((weak))
void spi_cs_activate(struct spi_slave *slave)
{
struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
writel(1 << slave->cs, altspi->base + ALTERA_SPI_SLAVE_SEL);
writel(ALTERA_SPI_CONTROL_SSO_MSK, altspi->base + ALTERA_SPI_CONTROL);
}
__attribute__((weak))
void spi_cs_deactivate(struct spi_slave *slave)
{
struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
writel(0, altspi->base + ALTERA_SPI_CONTROL);
writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL);
}
void spi_init(void)
{
}
void spi_set_speed(struct spi_slave *slave, uint hz)
{
/* altera spi core does not support programmable speed */
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct altera_spi_slave *altspi;
if (!spi_cs_is_valid(bus, cs))
return NULL;
altspi = spi_alloc_slave(struct altera_spi_slave, bus, cs);
if (!altspi)
return NULL;
altspi->base = altera_spi_base_list[bus];
debug("%s: bus:%i cs:%i base:%lx\n", __func__,
bus, cs, altspi->base);
return &altspi->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
free(altspi);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
writel(0, altspi->base + ALTERA_SPI_CONTROL);
writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL);
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
writel(0, altspi->base + ALTERA_SPI_SLAVE_SEL);
}
#ifndef CONFIG_ALTERA_SPI_IDLE_VAL
# define CONFIG_ALTERA_SPI_IDLE_VAL 0xff
#endif
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct altera_spi_slave *altspi = to_altera_spi_slave(slave);
/* assume spi core configured to do 8 bit transfers */
uint bytes = bitlen / 8;
const uchar *txp = dout;
uchar *rxp = din;
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;
if (bitlen % 8) {
flags |= SPI_XFER_END;
goto done;
}
/* empty read buffer */
if (readl(altspi->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK)
readl(altspi->base + ALTERA_SPI_RXDATA);
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
while (bytes--) {
uchar d = txp ? *txp++ : CONFIG_ALTERA_SPI_IDLE_VAL;
debug("%s: tx:%x ", __func__, d);
writel(d, altspi->base + ALTERA_SPI_TXDATA);
while (!(readl(altspi->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK))
;
d = readl(altspi->base + ALTERA_SPI_RXDATA);
if (rxp)
*rxp++ = d;
debug("rx:%x\n", d);
}
done:
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return 0;
}