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/*
* (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.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#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 */
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