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/*
* (C) Copyright 2009
* Marvell Semiconductor <www.marvell.com>
* Written-by: Prafulla Wadaskar <prafulla@marvell.com>
*
* Derived from drivers/spi/mpc8xxx_spi.c
*
* 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/arch/kirkwood.h>
#include <asm/arch/spi.h>
#include <asm/arch/mpp.h>
static struct kwspi_registers *spireg = (struct kwspi_registers *)KW_SPI_BASE;
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct spi_slave *slave;
u32 data;
u32 kwspi_mpp_config[] = {
MPP0_GPIO,
MPP7_SPI_SCn,
0
};
if (!spi_cs_is_valid(bus, cs))
return NULL;
slave = malloc(sizeof(struct spi_slave));
if (!slave)
return NULL;
slave->bus = bus;
slave->cs = cs;
writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl);
/* calculate spi clock prescaller using max_hz */
data = ((CONFIG_SYS_TCLK / 2) / max_hz) & KWSPI_CLKPRESCL_MASK;
data |= 0x10;
/* program spi clock prescaller using max_hz */
writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
debug("data = 0x%08x \n", data);
writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
writel(KWSPI_IRQMASK, spireg->irq_mask);
/* program mpp registers to select SPI_CSn */
if (cs) {
kwspi_mpp_config[0] = MPP0_GPIO;
kwspi_mpp_config[1] = MPP7_SPI_SCn;
} else {
kwspi_mpp_config[0] = MPP0_SPI_SCn;
kwspi_mpp_config[1] = MPP7_GPO;
}
kirkwood_mpp_conf(kwspi_mpp_config);
return slave;
}
void spi_free_slave(struct spi_slave *slave)
{
free(slave);
}
int spi_claim_bus(struct spi_slave *slave)
{
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
}
#ifndef CONFIG_SPI_CS_IS_VALID
/*
* you can define this function board specific
* define above CONFIG in board specific config file and
* provide the function in board specific src file
*/
int spi_cs_is_valid(unsigned int bus, unsigned int cs)
{
return (bus == 0 && (cs == 0 || cs == 1));
}
#endif
void spi_cs_activate(struct spi_slave *slave)
{
writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl);
}
void spi_cs_deactivate(struct spi_slave *slave)
{
writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl);
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
unsigned int tmpdout, tmpdin;
int tm, isread = 0;
debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
slave->bus, slave->cs, dout, din, bitlen);
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
/*
* handle data in 8-bit chunks
* TBD: 2byte xfer mode to be enabled
*/
writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) |
KWSPI_XFERLEN_1BYTE), &spireg->cfg);
while (bitlen > 4) {
debug("loopstart bitlen %d\n", bitlen);
tmpdout = 0;
/* Shift data so it's msb-justified */
if (dout)
tmpdout = *(u32 *) dout & 0x0ff;
writel(~KWSPI_SMEMRDIRQ, &spireg->irq_cause);
writel(tmpdout, &spireg->dout); /* Write the data out */
debug("*** spi_xfer: ... %08x written, bitlen %d\n",
tmpdout, bitlen);
/*
* Wait for SPI transmit to get out
* or time out (1 second = 1000 ms)
* The NE event must be read and cleared first
*/
for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
isread = 1;
tmpdin = readl(&spireg->din);
debug
("spi_xfer: din %08x..%08x read\n",
din, tmpdin);
if (din) {
*((u8 *) din) = (u8) tmpdin;
din += 1;
}
if (dout)
dout += 1;
bitlen -= 8;
}
if (isread)
break;
}
if (tm >= KWSPI_TIMEOUT)
printf("*** spi_xfer: Time out during SPI transfer\n");
debug("loopend bitlen %d\n", bitlen);
}
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
return 0;
}
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