u-boot/arch/powerpc/cpu/mpc824x/drivers/i2c/i2c.c
Stefan Roese a47a12becf Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to
better match the Linux directory structure.

Please note that this patch also changes the "ppc" target in
MAKEALL to "powerpc" to match this new infrastructure. But "ppc"
is kept as an alias for now, to not break compatibility with
scripts using this name.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Anatolij Gustschin <agust@denx.de>
2010-04-21 23:42:38 +02:00

270 lines
5.4 KiB
C

/*
* (C) Copyright 2003
* Gleb Natapov <gnatapov@mrv.com>
* Some bits are taken from linux driver writen by adrian@humboldt.co.uk
*
* Hardware I2C driver for MPC107 PCI bridge.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#undef I2CDBG
#ifdef CONFIG_HARD_I2C
#include <i2c.h>
#define TIMEOUT (CONFIG_SYS_HZ/4)
#define I2C_Addr ((unsigned *)(CONFIG_SYS_EUMB_ADDR + 0x3000))
#define I2CADR &I2C_Addr[0]
#define I2CFDR &I2C_Addr[1]
#define I2CCCR &I2C_Addr[2]
#define I2CCSR &I2C_Addr[3]
#define I2CCDR &I2C_Addr[4]
#define MPC107_CCR_MEN 0x80
#define MPC107_CCR_MIEN 0x40
#define MPC107_CCR_MSTA 0x20
#define MPC107_CCR_MTX 0x10
#define MPC107_CCR_TXAK 0x08
#define MPC107_CCR_RSTA 0x04
#define MPC107_CSR_MCF 0x80
#define MPC107_CSR_MAAS 0x40
#define MPC107_CSR_MBB 0x20
#define MPC107_CSR_MAL 0x10
#define MPC107_CSR_SRW 0x04
#define MPC107_CSR_MIF 0x02
#define MPC107_CSR_RXAK 0x01
#define I2C_READ 1
#define I2C_WRITE 0
/* taken from linux include/asm-ppc/io.h */
inline unsigned in_le32 (volatile unsigned *addr)
{
unsigned ret;
__asm__ __volatile__ ("lwbrx %0,0,%1;\n"
"twi 0,%0,0;\n"
"isync":"=r" (ret): "r" (addr), "m" (*addr));
return ret;
}
inline void out_le32 (volatile unsigned *addr, int val)
{
__asm__ __volatile__ ("stwbrx %1,0,%2; eieio":"=m" (*addr):"r" (val),
"r" (addr));
}
#define writel(val, addr) out_le32(addr, val)
#define readl(addr) in_le32(addr)
void i2c_init (int speed, int slaveadd)
{
/* stop I2C controller */
writel (0x0, I2CCCR);
/* set clock */
writel (0x1020, I2CFDR);
/* write slave address */
writel (slaveadd, I2CADR);
/* clear status register */
writel (0x0, I2CCSR);
/* start I2C controller */
writel (MPC107_CCR_MEN, I2CCCR);
return;
}
static __inline__ int i2c_wait4bus (void)
{
ulong timeval = get_timer (0);
while (readl (I2CCSR) & MPC107_CSR_MBB)
if (get_timer (timeval) > TIMEOUT)
return -1;
return 0;
}
static __inline__ int i2c_wait (int write)
{
u32 csr;
ulong timeval = get_timer (0);
do {
csr = readl (I2CCSR);
if (!(csr & MPC107_CSR_MIF))
continue;
writel (0x0, I2CCSR);
if (csr & MPC107_CSR_MAL) {
#ifdef I2CDBG
printf ("i2c_wait: MAL\n");
#endif
return -1;
}
if (!(csr & MPC107_CSR_MCF)) {
#ifdef I2CDBG
printf ("i2c_wait: unfinished\n");
#endif
return -1;
}
if (write == I2C_WRITE && (csr & MPC107_CSR_RXAK)) {
#ifdef I2CDBG
printf ("i2c_wait: No RXACK\n");
#endif
return -1;
}
return 0;
} while (get_timer (timeval) < TIMEOUT);
#ifdef I2CDBG
printf ("i2c_wait: timed out\n");
#endif
return -1;
}
static __inline__ int i2c_write_addr (u8 dev, u8 dir, int rsta)
{
writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX |
(rsta ? MPC107_CCR_RSTA : 0), I2CCCR);
writel ((dev << 1) | dir, I2CCDR);
if (i2c_wait (I2C_WRITE) < 0)
return 0;
return 1;
}
static __inline__ int __i2c_write (u8 * data, int length)
{
int i;
writel (MPC107_CCR_MEN | MPC107_CCR_MSTA | MPC107_CCR_MTX, I2CCCR);
for (i = 0; i < length; i++) {
writel (data[i], I2CCDR);
if (i2c_wait (I2C_WRITE) < 0)
break;
}
return i;
}
static __inline__ int __i2c_read (u8 * data, int length)
{
int i;
writel (MPC107_CCR_MEN | MPC107_CCR_MSTA |
((length == 1) ? MPC107_CCR_TXAK : 0), I2CCCR);
/* dummy read */
readl (I2CCDR);
for (i = 0; i < length; i++) {
if (i2c_wait (I2C_READ) < 0)
break;
/* Generate ack on last next to last byte */
if (i == length - 2)
writel (MPC107_CCR_MEN | MPC107_CCR_MSTA |
MPC107_CCR_TXAK, I2CCCR);
/* Generate stop on last byte */
if (i == length - 1)
writel (MPC107_CCR_MEN | MPC107_CCR_TXAK, I2CCCR);
data[i] = readl (I2CCDR);
}
return i;
}
int i2c_read (u8 dev, uint addr, int alen, u8 * data, int length)
{
int i = 0;
u8 *a = (u8 *) & addr;
if (i2c_wait4bus () < 0)
goto exit;
if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
goto exit;
if (__i2c_write (&a[4 - alen], alen) != alen)
goto exit;
if (i2c_write_addr (dev, I2C_READ, 1) == 0)
goto exit;
i = __i2c_read (data, length);
exit:
writel (MPC107_CCR_MEN, I2CCCR);
return !(i == length);
}
int i2c_write (u8 dev, uint addr, int alen, u8 * data, int length)
{
int i = 0;
u8 *a = (u8 *) & addr;
if (i2c_wait4bus () < 0)
goto exit;
if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
goto exit;
if (__i2c_write (&a[4 - alen], alen) != alen)
goto exit;
i = __i2c_write (data, length);
exit:
writel (MPC107_CCR_MEN, I2CCCR);
return !(i == length);
}
int i2c_probe (uchar chip)
{
int tmp;
/*
* Try to read the first location of the chip. The underlying
* driver doesn't appear to support sending just the chip address
* and looking for an <ACK> back.
*/
udelay (10000);
return i2c_read (chip, 0, 1, (uchar *) &tmp, 1);
}
#endif /* CONFIG_HARD_I2C */