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/*
* i2c driver for Freescale mx31
*
* (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
*
* 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>
#if defined(CONFIG_HARD_I2C)
#include <asm/arch/mx31.h>
#include <asm/arch/mx31-regs.h>
#define IADR 0x00
#define IFDR 0x04
#define I2CR 0x08
#define I2SR 0x0c
#define I2DR 0x10
#define I2CR_IEN (1 << 7)
#define I2CR_IIEN (1 << 6)
#define I2CR_MSTA (1 << 5)
#define I2CR_MTX (1 << 4)
#define I2CR_TX_NO_AK (1 << 3)
#define I2CR_RSTA (1 << 2)
#define I2SR_ICF (1 << 7)
#define I2SR_IBB (1 << 5)
#define I2SR_IIF (1 << 1)
#define I2SR_RX_NO_AK (1 << 0)
#ifdef CONFIG_SYS_I2C_MX31_PORT1
#define I2C_BASE 0x43f80000
#elif defined (CONFIG_SYS_I2C_MX31_PORT2)
#define I2C_BASE 0x43f98000
#elif defined (CONFIG_SYS_I2C_MX31_PORT3)
#define I2C_BASE 0x43f84000
#else
#error "define CONFIG_SYS_I2C_MX31_PORTx to use the mx31 I2C driver"
#endif
#ifdef DEBUG
#define DPRINTF(args...) printf(args)
#else
#define DPRINTF(args...)
#endif
static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144,
160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960,
1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840};
void i2c_init(int speed, int unused)
{
int freq = mx31_get_ipg_clk();
int i;
for (i = 0; i < 0x1f; i++)
if (freq / div[i] <= speed)
break;
DPRINTF("%s: speed: %d\n",__FUNCTION__, speed);
__REG16(I2C_BASE + I2CR) = 0; /* Reset module */
__REG16(I2C_BASE + IFDR) = i;
__REG16(I2C_BASE + I2CR) = I2CR_IEN;
__REG16(I2C_BASE + I2SR) = 0;
}
static int wait_busy(void)
{
int timeout = 10000;
while (!(__REG16(I2C_BASE + I2SR) & I2SR_IIF) && --timeout)
udelay(1);
__REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
return timeout;
}
static int tx_byte(u8 byte)
{
__REG16(I2C_BASE + I2DR) = byte;
if (!wait_busy() || __REG16(I2C_BASE + I2SR) & I2SR_RX_NO_AK)
return -1;
return 0;
}
static int rx_byte(void)
{
if (!wait_busy())
return -1;
return __REG16(I2C_BASE + I2DR);
}
int i2c_probe(uchar chip)
{
int ret;
__REG16(I2C_BASE + I2CR) = 0; /* Reset module */
__REG16(I2C_BASE + I2CR) = I2CR_IEN;
__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX;
ret = tx_byte(chip << 1);
__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MTX;
return ret;
}
static int i2c_addr(uchar chip, uint addr, int alen)
{
__REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX;
if (tx_byte(chip << 1))
return -1;
while (alen--)
if (tx_byte((addr >> (alen * 8)) & 0xff))
return -1;
return 0;
}
int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
{
int timeout = 10000;
int ret;
DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",__FUNCTION__, chip, addr, alen, len);
if (i2c_addr(chip, addr, alen)) {
printf("i2c_addr failed\n");
return -1;
}
__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_MTX | I2CR_RSTA;
if (tx_byte(chip << 1 | 1))
return -1;
__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | ((len == 1) ? I2CR_TX_NO_AK : 0);
ret = __REG16(I2C_BASE + I2DR);
while (len--) {
if ((ret = rx_byte()) < 0)
return -1;
*buf++ = ret;
if (len <= 1)
__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MSTA | I2CR_TX_NO_AK;
}
wait_busy();
__REG16(I2C_BASE + I2CR) = I2CR_IEN;
while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
udelay(1);
return 0;
}
int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
{
int timeout = 10000;
DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",__FUNCTION__, chip, addr, alen, len);
if (i2c_addr(chip, addr, alen))
return -1;
while (len--)
if (tx_byte(*buf++))
return -1;
__REG16(I2C_BASE + I2CR) = I2CR_IEN;
while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
udelay(1);
return 0;
}
#endif /* CONFIG_HARD_I2C */
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