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u-boot/drivers/i2c/mv_i2c.c
Lei Wen d308c9d35a I2C: mv_i2c: fix multi-bus init issue 
When enable the multi-bus, the current_bus is not inited in the original
implementation, which make the i2c operation unpredicatable.

Signed-off-by: Lei Wen <leiwen@marvell.com>
2011-10-03 11:50:09 +02:00

488 lines
13 KiB
C
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/*
* (C) Copyright 2000
* Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
*
* (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Marius Groeger <mgroeger@sysgo.de>
*
* (C) Copyright 2003 Pengutronix e.K.
* Robert Schwebel <r.schwebel@pengutronix.de>
*
* (C) Copyright 2011 Marvell Inc.
* Lei Wen <leiwen@marvell.com>
*
* 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
*
* Back ported to the 8xx platform (from the 8260 platform) by
* Murray.Jensen@cmst.csiro.au, 27-Jan-01.
*/
#include <common.h>
#include <asm/io.h>
#ifdef CONFIG_HARD_I2C
#include <i2c.h>
#include "mv_i2c.h"
#ifdef DEBUG_I2C
#define PRINTD(x) printf x
#else
#define PRINTD(x)
#endif
/* All transfers are described by this data structure */
struct i2c_msg {
u8 condition;
u8 acknack;
u8 direction;
u8 data;
};
struct mv_i2c {
u32 ibmr;
u32 pad0;
u32 idbr;
u32 pad1;
u32 icr;
u32 pad2;
u32 isr;
u32 pad3;
u32 isar;
};
static struct mv_i2c *base;
static void i2c_board_init(struct mv_i2c *base)
{
#ifdef CONFIG_SYS_I2C_INIT_BOARD
u32 icr;
/*
* call board specific i2c bus reset routine before accessing the
* environment, which might be in a chip on that bus. For details
* about this problem see doc/I2C_Edge_Conditions.
*
* disable I2C controller first, otherwhise it thinks we want to
* talk to the slave port...
*/
icr = readl(&base->icr);
writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
i2c_init_board();
writel(icr, &base->icr);
#endif
}
#ifdef CONFIG_I2C_MULTI_BUS
static u32 i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG;
static unsigned int bus_initialized[CONFIG_MV_I2C_NUM];
static unsigned int current_bus;
int i2c_set_bus_num(unsigned int bus)
{
if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) {
printf("Bad bus: %d\n", bus);
return -1;
}
base = (struct mv_i2c *)i2c_regs[bus];
current_bus = bus;
if (!bus_initialized[current_bus]) {
i2c_board_init(base);
bus_initialized[current_bus] = 1;
}
return 0;
}
unsigned int i2c_get_bus_num(void)
{
return current_bus;
}
#endif
/*
* i2c_reset: - reset the host controller
*
*/
static void i2c_reset(void)
{
writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
writel(readl(&base->icr) | ICR_UR, &base->icr); /* reset the unit */
udelay(100);
writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
i2c_clk_enable();
writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
writel(I2C_ICR_INIT, &base->icr); /* set control reg values */
writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
udelay(100);
}
/*
* i2c_isr_set_cleared: - wait until certain bits of the I2C status register
* are set and cleared
*
* @return: 1 in case of success, 0 means timeout (no match within 10 ms).
*/
static int i2c_isr_set_cleared(unsigned long set_mask,
unsigned long cleared_mask)
{
int timeout = 1000, isr;
do {
isr = readl(&base->isr);
udelay(10);
if (timeout-- < 0)
return 0;
} while (((isr & set_mask) != set_mask)
|| ((isr & cleared_mask) != 0));
return 1;
}
/*
* i2c_transfer: - Transfer one byte over the i2c bus
*
* This function can tranfer a byte over the i2c bus in both directions.
* It is used by the public API functions.
*
* @return: 0: transfer successful
* -1: message is empty
* -2: transmit timeout
* -3: ACK missing
* -4: receive timeout
* -5: illegal parameters
* -6: bus is busy and couldn't be aquired
*/
int i2c_transfer(struct i2c_msg *msg)
{
int ret;
if (!msg)
goto transfer_error_msg_empty;
switch (msg->direction) {
case I2C_WRITE:
/* check if bus is not busy */
if (!i2c_isr_set_cleared(0, ISR_IBB))
goto transfer_error_bus_busy;
/* start transmission */
writel(readl(&base->icr) & ~ICR_START, &base->icr);
writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
writel(msg->data, &base->idbr);
if (msg->condition == I2C_COND_START)
writel(readl(&base->icr) | ICR_START, &base->icr);
if (msg->condition == I2C_COND_STOP)
writel(readl(&base->icr) | ICR_STOP, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDNAK)
writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDACK)
writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
writel(readl(&base->icr) | ICR_TB, &base->icr);
/* transmit register empty? */
if (!i2c_isr_set_cleared(ISR_ITE, 0))
goto transfer_error_transmit_timeout;
/* clear 'transmit empty' state */
writel(readl(&base->isr) | ISR_ITE, &base->isr);
/* wait for ACK from slave */
if (msg->acknack == I2C_ACKNAK_WAITACK)
if (!i2c_isr_set_cleared(0, ISR_ACKNAK))
goto transfer_error_ack_missing;
break;
case I2C_READ:
/* check if bus is not busy */
if (!i2c_isr_set_cleared(0, ISR_IBB))
goto transfer_error_bus_busy;
/* start receive */
writel(readl(&base->icr) & ~ICR_START, &base->icr);
writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
if (msg->condition == I2C_COND_START)
writel(readl(&base->icr) | ICR_START, &base->icr);
if (msg->condition == I2C_COND_STOP)
writel(readl(&base->icr) | ICR_STOP, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDNAK)
writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
if (msg->acknack == I2C_ACKNAK_SENDACK)
writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
writel(readl(&base->icr) | ICR_TB, &base->icr);
/* receive register full? */
if (!i2c_isr_set_cleared(ISR_IRF, 0))
goto transfer_error_receive_timeout;
msg->data = readl(&base->idbr);
/* clear 'receive empty' state */
writel(readl(&base->isr) | ISR_IRF, &base->isr);
break;
default:
goto transfer_error_illegal_param;
}
return 0;
transfer_error_msg_empty:
PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
ret = -1; goto i2c_transfer_finish;
transfer_error_transmit_timeout:
PRINTD(("i2c_transfer: error: transmit timeout\n"));
ret = -2; goto i2c_transfer_finish;
transfer_error_ack_missing:
PRINTD(("i2c_transfer: error: ACK missing\n"));
ret = -3; goto i2c_transfer_finish;
transfer_error_receive_timeout:
PRINTD(("i2c_transfer: error: receive timeout\n"));
ret = -4; goto i2c_transfer_finish;
transfer_error_illegal_param:
PRINTD(("i2c_transfer: error: illegal parameters\n"));
ret = -5; goto i2c_transfer_finish;
transfer_error_bus_busy:
PRINTD(("i2c_transfer: error: bus is busy\n"));
ret = -6; goto i2c_transfer_finish;
i2c_transfer_finish:
PRINTD(("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr)));
i2c_reset();
return ret;
}
/* ------------------------------------------------------------------------ */
/* API Functions */
/* ------------------------------------------------------------------------ */
void i2c_init(int speed, int slaveaddr)
{
#ifdef CONFIG_I2C_MULTI_BUS
current_bus = 0;
base = (struct mv_i2c *)i2c_regs[current_bus];
#else
base = (struct mv_i2c *)CONFIG_MV_I2C_REG;
#endif
i2c_board_init(base);
}
/*
* i2c_probe: - Test if a chip answers for a given i2c address
*
* @chip: address of the chip which is searched for
* @return: 0 if a chip was found, -1 otherwhise
*/
int i2c_probe(uchar chip)
{
struct i2c_msg msg;
i2c_reset();
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1) + 1;
if (i2c_transfer(&msg))
return -1;
msg.condition = I2C_COND_STOP;
msg.acknack = I2C_ACKNAK_SENDNAK;
msg.direction = I2C_READ;
msg.data = 0x00;
if (i2c_transfer(&msg))
return -1;
return 0;
}
/*
* i2c_read: - Read multiple bytes from an i2c device
*
* The higher level routines take into account that this function is only
* called with len < page length of the device (see configuration file)
*
* @chip: address of the chip which is to be read
* @addr: i2c data address within the chip
* @alen: length of the i2c data address (1..2 bytes)
* @buffer: where to write the data
* @len: how much byte do we want to read
* @return: 0 in case of success
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
struct i2c_msg msg;
u8 addr_bytes[3]; /* lowest...highest byte of data address */
PRINTD(("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
"len=0x%02x)\n", chip, addr, alen, len));
i2c_reset();
/* dummy chip address write */
PRINTD(("i2c_read: dummy chip address write\n"));
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1);
msg.data &= 0xFE;
if (i2c_transfer(&msg))
return -1;
/*
* send memory address bytes;
* alen defines how much bytes we have to send.
*/
/*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF);
addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF);
addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
while (--alen >= 0) {
PRINTD(("i2c_read: send memory word address byte %1d\n", alen));
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = addr_bytes[alen];
if (i2c_transfer(&msg))
return -1;
}
/* start read sequence */
PRINTD(("i2c_read: start read sequence\n"));
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1);
msg.data |= 0x01;
if (i2c_transfer(&msg))
return -1;
/* read bytes; send NACK at last byte */
while (len--) {
if (len == 0) {
msg.condition = I2C_COND_STOP;
msg.acknack = I2C_ACKNAK_SENDNAK;
} else {
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_SENDACK;
}
msg.direction = I2C_READ;
msg.data = 0x00;
if (i2c_transfer(&msg))
return -1;
*buffer = msg.data;
PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n",
(unsigned int)buffer, *buffer));
buffer++;
}
i2c_reset();
return 0;
}
/*
* i2c_write: - Write multiple bytes to an i2c device
*
* The higher level routines take into account that this function is only
* called with len < page length of the device (see configuration file)
*
* @chip: address of the chip which is to be written
* @addr: i2c data address within the chip
* @alen: length of the i2c data address (1..2 bytes)
* @buffer: where to find the data to be written
* @len: how much byte do we want to read
* @return: 0 in case of success
*/
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
struct i2c_msg msg;
u8 addr_bytes[3]; /* lowest...highest byte of data address */
PRINTD(("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
"len=0x%02x)\n", chip, addr, alen, len));
i2c_reset();
/* chip address write */
PRINTD(("i2c_write: chip address write\n"));
msg.condition = I2C_COND_START;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = (chip << 1);
msg.data &= 0xFE;
if (i2c_transfer(&msg))
return -1;
/*
* send memory address bytes;
* alen defines how much bytes we have to send.
*/
addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF);
addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF);
addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
while (--alen >= 0) {
PRINTD(("i2c_write: send memory word address\n"));
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = addr_bytes[alen];
if (i2c_transfer(&msg))
return -1;
}
/* write bytes; send NACK at last byte */
while (len--) {
PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n",
(unsigned int)buffer, *buffer));
if (len == 0)
msg.condition = I2C_COND_STOP;
else
msg.condition = I2C_COND_NORMAL;
msg.acknack = I2C_ACKNAK_WAITACK;
msg.direction = I2C_WRITE;
msg.data = *(buffer++);
if (i2c_transfer(&msg))
return -1;
}
i2c_reset();
return 0;
}
#endif /* CONFIG_HARD_I2C */
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