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/*
* (C) Copyright 2011
* eInfochips Ltd. <www.einfochips.com>
* Written-by: Ajay Bhargav <ajay.bhargav@einfochips.com>
*
* (C) Copyright 2009
* Marvell Semiconductor <www.marvell.com>
* Based on SSP driver
* Written-by: Lei Wen <leiwen@marvell.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301 USA
*/
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
#include <asm/arch/spi.h>
#include <asm/gpio.h>
#define to_armd_spi_slave(s) container_of(s, struct armd_spi_slave, slave)
struct armd_spi_slave {
struct spi_slave slave;
struct ssp_reg *spi_reg;
u32 cr0, cr1;
u32 int_cr1;
u32 clear_sr;
const void *tx;
void *rx;
int gpio_cs_inverted;
};
static int spi_armd_write(struct armd_spi_slave *pss)
{
int wait_timeout = SSP_FLUSH_NUM;
while (--wait_timeout && !(readl(&pss->spi_reg->sssr) & SSSR_TNF))
;
if (!wait_timeout) {
debug("%s: timeout error\n", __func__);
return -1;
}
if (pss->tx != NULL) {
writel(*(u8 *)pss->tx, &pss->spi_reg->ssdr);
++pss->tx;
} else {
writel(0, &pss->spi_reg->ssdr);
}
return 0;
}
static int spi_armd_read(struct armd_spi_slave *pss)
{
int wait_timeout = SSP_FLUSH_NUM;
while (--wait_timeout && !(readl(&pss->spi_reg->sssr) & SSSR_RNE))
;
if (!wait_timeout) {
debug("%s: timeout error\n", __func__);
return -1;
}
if (pss->rx != NULL) {
*(u8 *)pss->rx = readl(&pss->spi_reg->ssdr);
++pss->rx;
} else {
readl(&pss->spi_reg->ssdr);
}
return 0;
}
static int spi_armd_flush(struct armd_spi_slave *pss)
{
unsigned long limit = SSP_FLUSH_NUM;
do {
while (readl(&pss->spi_reg->sssr) & SSSR_RNE)
readl(&pss->spi_reg->ssdr);
} while ((readl(&pss->spi_reg->sssr) & SSSR_BSY) && limit--);
writel(SSSR_ROR, &pss->spi_reg->sssr);
return limit;
}
void spi_cs_activate(struct spi_slave *slave)
{
struct armd_spi_slave *pss = to_armd_spi_slave(slave);
gpio_set_value(slave->cs, pss->gpio_cs_inverted);
}
void spi_cs_deactivate(struct spi_slave *slave)
{
struct armd_spi_slave *pss = to_armd_spi_slave(slave);
gpio_set_value(slave->cs, !pss->gpio_cs_inverted);
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct armd_spi_slave *pss;
pss = malloc(sizeof(*pss));
if (!pss)
return NULL;
pss->slave.bus = bus;
pss->slave.cs = cs;
pss->spi_reg = (struct ssp_reg *)SSP_REG_BASE(CONFIG_SYS_SSP_PORT);
pss->cr0 = SSCR0_MOTO | SSCR0_DATASIZE(DEFAULT_WORD_LEN) | SSCR0_SSE;
pss->cr1 = (SSCR1_RXTRESH(RX_THRESH_DEF) & SSCR1_RFT) |
(SSCR1_TXTRESH(TX_THRESH_DEF) & SSCR1_TFT);
pss->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
pss->cr1 |= (((mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
| (((mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
pss->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
pss->clear_sr = SSSR_ROR | SSSR_TINT;
pss->gpio_cs_inverted = mode & SPI_CS_HIGH;
gpio_set_value(cs, !pss->gpio_cs_inverted);
return &pss->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct armd_spi_slave *pss = to_armd_spi_slave(slave);
free(pss);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct armd_spi_slave *pss = to_armd_spi_slave(slave);
debug("%s: bus:%i cs:%i\n", __func__, slave->bus, slave->cs);
if (spi_armd_flush(pss) == 0)
return -1;
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
struct armd_spi_slave *pss = to_armd_spi_slave(slave);
uint bytes = bitlen / 8;
unsigned long limit;
int ret = 0;
if (bitlen == 0)
goto done;
/* we can only do 8 bit transfers */
if (bitlen % 8) {
flags |= SPI_XFER_END;
goto done;
}
if (dout)
pss->tx = dout;
else
pss->tx = NULL;
if (din)
pss->rx = din;
else
pss->rx = NULL;
if (flags & SPI_XFER_BEGIN) {
spi_cs_activate(slave);
writel(pss->cr1 | pss->int_cr1, &pss->spi_reg->sscr1);
writel(TIMEOUT_DEF, &pss->spi_reg->ssto);
writel(pss->cr0, &pss->spi_reg->sscr0);
}
while (bytes--) {
limit = SSP_FLUSH_NUM;
ret = spi_armd_write(pss);
if (ret)
break;
while ((readl(&pss->spi_reg->sssr) & SSSR_BSY) && limit--)
udelay(1);
ret = spi_armd_read(pss);
if (ret)
break;
}
done:
if (flags & SPI_XFER_END) {
/* Stop SSP */
writel(pss->clear_sr, &pss->spi_reg->sssr);
clrbits_le32(&pss->spi_reg->sscr1, pss->int_cr1);
writel(0, &pss->spi_reg->ssto);
spi_cs_deactivate(slave);
}
return ret;
}
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