1
0
Fork 0

blackfin: make i2c driver blackfin independant

The ADI twi peripheral is not binding to Blackfin processor only.
Access i2c registers by standard io functions.
Fix coding style.

Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
utp
Scott Jiang 2014-01-28 13:53:36 +08:00 committed by Heiko Schocher
parent 86bdd70a09
commit 16c550274c
1 changed files with 80 additions and 71 deletions

View File

@ -1,7 +1,7 @@
/*
* i2c.c - driver for Blackfin on-chip TWI/I2C
* i2c.c - driver for ADI TWI/I2C
*
* Copyright (c) 2006-2010 Analog Devices Inc.
* Copyright (c) 2006-2013 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
@ -11,6 +11,7 @@
#include <asm/clock.h>
#include <asm/twi.h>
#include <asm/io.h>
/* Every register is 32bit aligned, but only 16bits in size */
#define ureg(name) u16 name; u16 __pad_##name;
@ -39,7 +40,7 @@ struct twi_regs {
#ifdef TWI_CLKDIV
#define TWI0_CLKDIV TWI_CLKDIV
#endif
static volatile struct twi_regs *twi = (void *)TWI0_CLKDIV;
static struct twi_regs *twi = (void *)TWI0_CLKDIV;
#ifdef DEBUG
# define dmemset(s, c, n) memset(s, c, n)
@ -93,53 +94,54 @@ struct i2c_msg {
*/
static int wait_for_completion(struct i2c_msg *msg)
{
uint16_t int_stat;
u16 int_stat, ctl;
ulong timebase = get_timer(0);
do {
int_stat = twi->int_stat;
int_stat = readw(&twi->int_stat);
if (int_stat & XMTSERV) {
debugi("processing XMTSERV");
twi->int_stat = XMTSERV;
SSYNC();
writew(XMTSERV, &twi->int_stat);
if (msg->alen) {
twi->xmt_data8 = *(msg->abuf++);
writew(*(msg->abuf++), &twi->xmt_data8);
--msg->alen;
} else if (!(msg->flags & I2C_M_COMBO) && msg->len) {
twi->xmt_data8 = *(msg->buf++);
writew(*(msg->buf++), &twi->xmt_data8);
--msg->len;
} else {
twi->master_ctl |= (msg->flags & I2C_M_COMBO) ? RSTART | MDIR : STOP;
SSYNC();
ctl = readw(&twi->master_ctl);
if (msg->flags & I2C_M_COMBO)
writew(ctl | RSTART | MDIR,
&twi->master_ctl);
else
writew(ctl | STOP, &twi->master_ctl);
}
}
if (int_stat & RCVSERV) {
debugi("processing RCVSERV");
twi->int_stat = RCVSERV;
SSYNC();
writew(RCVSERV, &twi->int_stat);
if (msg->len) {
*(msg->buf++) = twi->rcv_data8;
*(msg->buf++) = readw(&twi->rcv_data8);
--msg->len;
} else if (msg->flags & I2C_M_STOP) {
twi->master_ctl |= STOP;
SSYNC();
ctl = readw(&twi->master_ctl);
writew(ctl | STOP, &twi->master_ctl);
}
}
if (int_stat & MERR) {
debugi("processing MERR");
twi->int_stat = MERR;
SSYNC();
writew(MERR, &twi->int_stat);
return msg->len;
}
if (int_stat & MCOMP) {
debugi("processing MCOMP");
twi->int_stat = MCOMP;
SSYNC();
writew(MCOMP, &twi->int_stat);
if (msg->flags & I2C_M_COMBO && msg->len) {
twi->master_ctl = (twi->master_ctl & ~RSTART) |
ctl = readw(&twi->master_ctl);
ctl = (ctl & ~RSTART) |
(min(msg->len, 0xff) << 6) | MEN | MDIR;
SSYNC();
writew(ctl, &twi->master_ctl);
} else
break;
}
@ -160,8 +162,11 @@ static int wait_for_completion(struct i2c_msg *msg)
* Here we just get the i2c stuff all prepped and ready, and then tail off
* into wait_for_completion() for all the bits to go.
*/
static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, int len, u8 flags)
static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer,
int len, u8 flags)
{
int ret;
u16 ctl;
uchar addr_buffer[] = {
(addr >> 0),
(addr >> 8),
@ -174,62 +179,59 @@ static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, int len,
.abuf = addr_buffer,
.alen = alen,
};
int ret;
dmemset(buffer, 0xff, len);
debugi("chip=0x%x addr=0x%02x alen=%i buf[0]=0x%02x len=%i flags=0x%02x[%s] ",
chip, addr, alen, buffer[0], len, flags, (flags & I2C_M_READ ? "rd" : "wr"));
debugi("chip=0x%x addr=0x%02x alen=%i buf[0]=0x%02x len=%i ",
chip, addr, alen, buffer[0], len);
debugi("flags=0x%02x[%s] ", flags,
(flags & I2C_M_READ ? "rd" : "wr"));
/* wait for things to settle */
while (twi->master_stat & BUSBUSY)
while (readw(&twi->master_stat) & BUSBUSY)
if (ctrlc())
return 1;
/* Set Transmit device address */
twi->master_addr = chip;
writew(chip, &twi->master_addr);
/* Clear the FIFO before starting things */
twi->fifo_ctl = XMTFLUSH | RCVFLUSH;
SSYNC();
twi->fifo_ctl = 0;
SSYNC();
writew(XMTFLUSH | RCVFLUSH, &twi->fifo_ctl);
writew(0, &twi->fifo_ctl);
/* prime the pump */
if (msg.alen) {
len = (msg.flags & I2C_M_COMBO) ? msg.alen : msg.alen + len;
debugi("first byte=0x%02x", *msg.abuf);
twi->xmt_data8 = *(msg.abuf++);
writew(*(msg.abuf++), &twi->xmt_data8);
--msg.alen;
} else if (!(msg.flags & I2C_M_READ) && msg.len) {
debugi("first byte=0x%02x", *msg.buf);
twi->xmt_data8 = *(msg.buf++);
writew(*(msg.buf++), &twi->xmt_data8);
--msg.len;
}
/* clear int stat */
twi->master_stat = -1;
twi->int_stat = -1;
twi->int_mask = 0;
SSYNC();
writew(-1, &twi->master_stat);
writew(-1, &twi->int_stat);
writew(0, &twi->int_mask);
/* Master enable */
twi->master_ctl =
(twi->master_ctl & FAST) |
(min(len, 0xff) << 6) | MEN |
((msg.flags & I2C_M_READ) ? MDIR : 0);
SSYNC();
debugi("CTL=0x%04x", twi->master_ctl);
ctl = readw(&twi->master_ctl);
ctl = (ctl & FAST) | (min(len, 0xff) << 6) | MEN |
((msg.flags & I2C_M_READ) ? MDIR : 0);
writew(ctl, &twi->master_ctl);
/* process the rest */
ret = wait_for_completion(&msg);
debugi("ret=%d", ret);
if (ret) {
twi->master_ctl &= ~MEN;
twi->control &= ~TWI_ENA;
SSYNC();
twi->control |= TWI_ENA;
SSYNC();
ctl = readw(&twi->master_ctl) & ~MEN;
writew(ctl, &twi->master_ctl);
ctl = readw(&twi->control) & ~TWI_ENA;
writew(ctl, &twi->control);
ctl = readw(&twi->control) | TWI_ENA;
writew(ctl, &twi->control);
}
return ret;
@ -246,10 +248,11 @@ int i2c_set_bus_speed(unsigned int speed)
/* Set TWI interface clock */
if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN)
return -1;
twi->clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
clkdiv = (clkdiv << 8) | (clkdiv & 0xff);
writew(clkdiv, &twi->clkdiv);
/* Don't turn it on */
twi->master_ctl = (speed > 100000 ? FAST : 0);
writew(speed > 100000 ? FAST : 0, &twi->master_ctl);
return 0;
}
@ -260,8 +263,9 @@ int i2c_set_bus_speed(unsigned int speed)
*/
unsigned int i2c_get_bus_speed(void)
{
u16 clkdiv = readw(&twi->clkdiv) & 0xff;
/* 10 MHz / (2 * CLKDIV) -> 5 MHz / CLKDIV */
return 5000000 / (twi->clkdiv & 0xff);
return 5000000 / clkdiv;
}
/**
@ -274,27 +278,22 @@ unsigned int i2c_get_bus_speed(void)
*/
void i2c_init(int speed, int slaveaddr)
{
uint8_t prescale = ((get_i2c_clk() / 1000 / 1000 + 5) / 10) & 0x7F;
u16 prescale = ((get_i2c_clk() / 1000 / 1000 + 5) / 10) & 0x7F;
/* Set TWI internal clock as 10MHz */
twi->control = prescale;
writew(prescale, &twi->control);
/* Set TWI interface clock as specified */
i2c_set_bus_speed(speed);
/* Enable it */
twi->control = TWI_ENA | prescale;
SSYNC();
writew(TWI_ENA | prescale, &twi->control);
debugi("CONTROL:0x%04x CLKDIV:0x%04x", twi->control, twi->clkdiv);
debugi("CONTROL:0x%04x CLKDIV:0x%04x", readw(&twi->control),
readw(&twi->clkdiv));
#if CONFIG_SYS_I2C_SLAVE
# error I2C slave support not tested/supported
/* If they want us as a slave, do it */
if (slaveaddr) {
twi->slave_addr = slaveaddr;
twi->slave_ctl = SEN;
}
#endif
}
@ -320,7 +319,8 @@ int i2c_probe(uchar chip)
*/
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
{
return i2c_transfer(chip, addr, alen, buffer, len, (alen ? I2C_M_COMBO : I2C_M_READ));
return i2c_transfer(chip, addr, alen, buffer,
len, (alen ? I2C_M_COMBO : I2C_M_READ));
}
/**
@ -346,15 +346,21 @@ int i2c_set_bus_num(unsigned int bus)
{
switch (bus) {
#if CONFIG_SYS_MAX_I2C_BUS > 0
case 0: twi = (void *)TWI0_CLKDIV; return 0;
case 0:
twi = (void *)TWI0_CLKDIV;
return 0;
#endif
#if CONFIG_SYS_MAX_I2C_BUS > 1
case 1: twi = (void *)TWI1_CLKDIV; return 0;
case 1:
twi = (void *)TWI1_CLKDIV;
return 0;
#endif
#if CONFIG_SYS_MAX_I2C_BUS > 2
case 2: twi = (void *)TWI2_CLKDIV; return 0;
case 2:
twi = (void *)TWI2_CLKDIV;
return 0;
#endif
default: return -1;
default: return -1;
}
}
@ -365,14 +371,17 @@ unsigned int i2c_get_bus_num(void)
{
switch ((unsigned long)twi) {
#if CONFIG_SYS_MAX_I2C_BUS > 0
case TWI0_CLKDIV: return 0;
case TWI0_CLKDIV:
return 0;
#endif
#if CONFIG_SYS_MAX_I2C_BUS > 1
case TWI1_CLKDIV: return 1;
case TWI1_CLKDIV:
return 1;
#endif
#if CONFIG_SYS_MAX_I2C_BUS > 2
case TWI2_CLKDIV: return 2;
case TWI2_CLKDIV:
return 2;
#endif
default: return -1;
default: return -1;
}
}