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/*
* Copyright (C) 2008, Guennadi Liakhovetski <lg@denx.de>
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
#include <common.h>
#include <malloc.h>
#include <spi.h>
#include <asm/io.h>
#ifdef CONFIG_MX27
/* i.MX27 has a completely wrong register layout and register definitions in the
* datasheet, the correct one is in the Freescale's Linux driver */
#error "i.MX27 CSPI not supported due to drastic differences in register definisions" \
"See linux mxc_spi driver from Freescale for details."
#else
#define MXC_CSPIRXDATA 0x00
#define MXC_CSPITXDATA 0x04
#define MXC_CSPICTRL 0x08
#define MXC_CSPIINT 0x0C
#define MXC_CSPIDMA 0x10
#define MXC_CSPISTAT 0x14
#define MXC_CSPIPERIOD 0x18
#define MXC_CSPITEST 0x1C
#define MXC_CSPIRESET 0x00
#define MXC_CSPICTRL_EN (1 << 0)
#define MXC_CSPICTRL_MODE (1 << 1)
#define MXC_CSPICTRL_XCH (1 << 2)
#define MXC_CSPICTRL_SMC (1 << 3)
#define MXC_CSPICTRL_POL (1 << 4)
#define MXC_CSPICTRL_PHA (1 << 5)
#define MXC_CSPICTRL_SSCTL (1 << 6)
#define MXC_CSPICTRL_SSPOL (1 << 7)
#define MXC_CSPICTRL_CHIPSELECT(x) (((x) & 0x3) << 24)
#define MXC_CSPICTRL_BITCOUNT(x) (((x) & 0x1f) << 8)
#define MXC_CSPICTRL_DATARATE(x) (((x) & 0x7) << 16)
#define MXC_CSPIPERIOD_32KHZ (1 << 15)
static unsigned long spi_bases[] = {
0x43fa4000,
0x50010000,
0x53f84000,
};
#endif
struct mxc_spi_slave {
struct spi_slave slave;
unsigned long base;
u32 ctrl_reg;
};
static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
{
return container_of(slave, struct mxc_spi_slave, slave);
}
static inline u32 reg_read(unsigned long addr)
{
return *(volatile unsigned long*)addr;
}
static inline void reg_write(unsigned long addr, u32 val)
{
*(volatile unsigned long*)addr = val;
}
static u32 spi_xchg_single(struct spi_slave *slave, u32 data, int bitlen)
{
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
unsigned int cfg_reg = reg_read(mxcs->base + MXC_CSPICTRL);
mxcs->ctrl_reg = (mxcs->ctrl_reg & ~MXC_CSPICTRL_BITCOUNT(31)) |
MXC_CSPICTRL_BITCOUNT(bitlen - 1);
if (cfg_reg != mxcs->ctrl_reg)
reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg);
reg_write(mxcs->base + MXC_CSPITXDATA, data);
reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg | MXC_CSPICTRL_XCH);
while (reg_read(mxcs->base + MXC_CSPICTRL) & MXC_CSPICTRL_XCH)
;
return reg_read(mxcs->base + MXC_CSPIRXDATA);
}
int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
void *din, unsigned long flags)
{
int n_blks = (bitlen + 31) / 32;
u32 *out_l, *in_l;
int i;
if ((int)dout & 3 || (int)din & 3) {
printf("Error: unaligned buffers in: %p, out: %p\n", din, dout);
return 1;
}
for (i = 0, in_l = (u32 *)din, out_l = (u32 *)dout;
i < n_blks;
i++, in_l++, out_l++, bitlen -= 32) {
u32 data = spi_xchg_single(slave, *out_l, bitlen);
/* Check if we're only transfering 8 or 16 bits */
if (!i) {
if (bitlen < 9)
*(u8 *)din = data;
else if (bitlen < 17)
*(u16 *)din = data;
}
}
return 0;
}
void spi_init(void)
{
}
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
unsigned int ctrl_reg;
struct mxc_spi_slave *mxcs;
if (bus >= sizeof(spi_bases) / sizeof(spi_bases[0]) ||
cs > 3)
return NULL;
ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) |
MXC_CSPICTRL_BITCOUNT(31) |
MXC_CSPICTRL_DATARATE(7) | /* FIXME: calculate data rate */
MXC_CSPICTRL_EN |
MXC_CSPICTRL_MODE;
if (mode & SPI_CPHA)
ctrl_reg |= MXC_CSPICTRL_PHA;
if (!(mode & SPI_CPOL))
ctrl_reg |= MXC_CSPICTRL_POL;
if (mode & SPI_CS_HIGH)
ctrl_reg |= MXC_CSPICTRL_SSPOL;
mxcs = malloc(sizeof(struct mxc_spi_slave));
if (!mxcs)
return NULL;
mxcs->slave.bus = bus;
mxcs->slave.cs = cs;
mxcs->base = spi_bases[bus];
mxcs->ctrl_reg = ctrl_reg;
return &mxcs->slave;
}
void spi_free_slave(struct spi_slave *slave)
{
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
free(mxcs);
}
int spi_claim_bus(struct spi_slave *slave)
{
struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
reg_write(mxcs->base + MXC_CSPIRESET, 1);
udelay(1);
reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg);
reg_write(mxcs->base + MXC_CSPIPERIOD,
MXC_CSPIPERIOD_32KHZ);
reg_write(mxcs->base + MXC_CSPIINT, 0);
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
/* TODO: Shut the controller down */
}
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