u-boot/drivers/i2c/davinci_i2c.c

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/*
* TI DaVinci (TMS320DM644x) I2C driver.
*
* (C) Copyright 2012-2014
* Texas Instruments Incorporated, <www.ti.com>
* (C) Copyright 2007 Sergey Kubushyn <ksi@koi8.net>
* --------------------------------------------------------
*
* SPDX-License-Identifier: GPL-2.0+
*
* NOTE: This driver should be converted to driver model before June 2017.
* Please see doc/driver-model/i2c-howto.txt for instructions.
*/
#include <common.h>
#include <i2c.h>
#include <asm/arch/hardware.h>
#include <asm/arch/i2c_defs.h>
#include <asm/io.h>
#include "davinci_i2c.h"
#define CHECK_NACK() \
do {\
if (tmp & (I2C_TIMEOUT | I2C_STAT_NACK)) {\
REG(&(i2c_base->i2c_con)) = 0;\
return 1;\
} \
} while (0)
static struct i2c_regs *davinci_get_base(struct i2c_adapter *adap);
static int wait_for_bus(struct i2c_adapter *adap)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
int stat, timeout;
REG(&(i2c_base->i2c_stat)) = 0xffff;
for (timeout = 0; timeout < 10; timeout++) {
stat = REG(&(i2c_base->i2c_stat));
if (!((stat) & I2C_STAT_BB)) {
REG(&(i2c_base->i2c_stat)) = 0xffff;
return 0;
}
REG(&(i2c_base->i2c_stat)) = stat;
udelay(50000);
}
REG(&(i2c_base->i2c_stat)) = 0xffff;
return 1;
}
static int poll_i2c_irq(struct i2c_adapter *adap, int mask)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
int stat, timeout;
for (timeout = 0; timeout < 10; timeout++) {
udelay(1000);
stat = REG(&(i2c_base->i2c_stat));
if (stat & mask)
return stat;
}
REG(&(i2c_base->i2c_stat)) = 0xffff;
return stat | I2C_TIMEOUT;
}
static void flush_rx(struct i2c_adapter *adap)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
while (1) {
if (!(REG(&(i2c_base->i2c_stat)) & I2C_STAT_RRDY))
break;
REG(&(i2c_base->i2c_drr));
REG(&(i2c_base->i2c_stat)) = I2C_STAT_RRDY;
udelay(1000);
}
}
static uint davinci_i2c_setspeed(struct i2c_adapter *adap, uint speed)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
uint32_t div, psc;
psc = 2;
/* SCLL + SCLH */
div = (CONFIG_SYS_HZ_CLOCK / ((psc + 1) * speed)) - 10;
REG(&(i2c_base->i2c_psc)) = psc; /* 27MHz / (2 + 1) = 9MHz */
REG(&(i2c_base->i2c_scll)) = (div * 50) / 100; /* 50% Duty */
REG(&(i2c_base->i2c_sclh)) = div - REG(&(i2c_base->i2c_scll));
adap->speed = speed;
return 0;
}
static void davinci_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
if (REG(&(i2c_base->i2c_con)) & I2C_CON_EN) {
REG(&(i2c_base->i2c_con)) = 0;
udelay(50000);
}
davinci_i2c_setspeed(adap, speed);
REG(&(i2c_base->i2c_oa)) = slaveadd;
REG(&(i2c_base->i2c_cnt)) = 0;
/* Interrupts must be enabled or I2C module won't work */
REG(&(i2c_base->i2c_ie)) = I2C_IE_SCD_IE | I2C_IE_XRDY_IE |
I2C_IE_RRDY_IE | I2C_IE_ARDY_IE | I2C_IE_NACK_IE;
/* Now enable I2C controller (get it out of reset) */
REG(&(i2c_base->i2c_con)) = I2C_CON_EN;
udelay(1000);
}
static int davinci_i2c_probe(struct i2c_adapter *adap, uint8_t chip)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
int rc = 1;
if (chip == REG(&(i2c_base->i2c_oa)))
return rc;
REG(&(i2c_base->i2c_con)) = 0;
if (wait_for_bus(adap))
return 1;
/* try to read one byte from current (or only) address */
REG(&(i2c_base->i2c_cnt)) = 1;
REG(&(i2c_base->i2c_sa)) = chip;
REG(&(i2c_base->i2c_con)) = (I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
I2C_CON_STP);
udelay(50000);
if (!(REG(&(i2c_base->i2c_stat)) & I2C_STAT_NACK)) {
rc = 0;
flush_rx(adap);
REG(&(i2c_base->i2c_stat)) = 0xffff;
} else {
REG(&(i2c_base->i2c_stat)) = 0xffff;
REG(&(i2c_base->i2c_con)) |= I2C_CON_STP;
udelay(20000);
if (wait_for_bus(adap))
return 1;
}
flush_rx(adap);
REG(&(i2c_base->i2c_stat)) = 0xffff;
REG(&(i2c_base->i2c_cnt)) = 0;
return rc;
}
static int davinci_i2c_read(struct i2c_adapter *adap, uint8_t chip,
uint32_t addr, int alen, uint8_t *buf, int len)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
uint32_t tmp;
int i;
if ((alen < 0) || (alen > 2)) {
printf("%s(): bogus address length %x\n", __func__, alen);
return 1;
}
if (wait_for_bus(adap))
return 1;
if (alen != 0) {
/* Start address phase */
tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX;
REG(&(i2c_base->i2c_cnt)) = alen;
REG(&(i2c_base->i2c_sa)) = chip;
REG(&(i2c_base->i2c_con)) = tmp;
tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
switch (alen) {
case 2:
/* Send address MSByte */
if (tmp & I2C_STAT_XRDY) {
REG(&(i2c_base->i2c_dxr)) = (addr >> 8) & 0xff;
} else {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
/* No break, fall through */
case 1:
/* Send address LSByte */
if (tmp & I2C_STAT_XRDY) {
REG(&(i2c_base->i2c_dxr)) = addr & 0xff;
} else {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
tmp = poll_i2c_irq(adap, I2C_STAT_XRDY |
I2C_STAT_NACK | I2C_STAT_ARDY);
CHECK_NACK();
if (!(tmp & I2C_STAT_ARDY)) {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
}
}
/* Address phase is over, now read 'len' bytes and stop */
tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP;
REG(&(i2c_base->i2c_cnt)) = len & 0xffff;
REG(&(i2c_base->i2c_sa)) = chip;
REG(&(i2c_base->i2c_con)) = tmp;
for (i = 0; i < len; i++) {
tmp = poll_i2c_irq(adap, I2C_STAT_RRDY | I2C_STAT_NACK |
I2C_STAT_ROVR);
CHECK_NACK();
if (tmp & I2C_STAT_RRDY) {
buf[i] = REG(&(i2c_base->i2c_drr));
} else {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
}
tmp = poll_i2c_irq(adap, I2C_STAT_SCD | I2C_STAT_NACK);
CHECK_NACK();
if (!(tmp & I2C_STAT_SCD)) {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
flush_rx(adap);
REG(&(i2c_base->i2c_stat)) = 0xffff;
REG(&(i2c_base->i2c_cnt)) = 0;
REG(&(i2c_base->i2c_con)) = 0;
return 0;
}
static int davinci_i2c_write(struct i2c_adapter *adap, uint8_t chip,
uint32_t addr, int alen, uint8_t *buf, int len)
{
struct i2c_regs *i2c_base = davinci_get_base(adap);
uint32_t tmp;
int i;
if ((alen < 0) || (alen > 2)) {
printf("%s(): bogus address length %x\n", __func__, alen);
return 1;
}
if (len < 0) {
printf("%s(): bogus length %x\n", __func__, len);
return 1;
}
if (wait_for_bus(adap))
return 1;
/* Start address phase */
tmp = I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
I2C_CON_TRX | I2C_CON_STP;
REG(&(i2c_base->i2c_cnt)) = (alen == 0) ?
len & 0xffff : (len & 0xffff) + alen;
REG(&(i2c_base->i2c_sa)) = chip;
REG(&(i2c_base->i2c_con)) = tmp;
switch (alen) {
case 2:
/* Send address MSByte */
tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
if (tmp & I2C_STAT_XRDY) {
REG(&(i2c_base->i2c_dxr)) = (addr >> 8) & 0xff;
} else {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
/* No break, fall through */
case 1:
/* Send address LSByte */
tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
if (tmp & I2C_STAT_XRDY) {
REG(&(i2c_base->i2c_dxr)) = addr & 0xff;
} else {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
}
for (i = 0; i < len; i++) {
tmp = poll_i2c_irq(adap, I2C_STAT_XRDY | I2C_STAT_NACK);
CHECK_NACK();
if (tmp & I2C_STAT_XRDY)
REG(&(i2c_base->i2c_dxr)) = buf[i];
else
return 1;
}
tmp = poll_i2c_irq(adap, I2C_STAT_SCD | I2C_STAT_NACK);
CHECK_NACK();
if (!(tmp & I2C_STAT_SCD)) {
REG(&(i2c_base->i2c_con)) = 0;
return 1;
}
flush_rx(adap);
REG(&(i2c_base->i2c_stat)) = 0xffff;
REG(&(i2c_base->i2c_cnt)) = 0;
REG(&(i2c_base->i2c_con)) = 0;
return 0;
}
static struct i2c_regs *davinci_get_base(struct i2c_adapter *adap)
{
switch (adap->hwadapnr) {
#if I2C_BUS_MAX >= 3
case 2:
return (struct i2c_regs *)I2C2_BASE;
#endif
#if I2C_BUS_MAX >= 2
case 1:
return (struct i2c_regs *)I2C1_BASE;
#endif
case 0:
return (struct i2c_regs *)I2C_BASE;
default:
printf("wrong hwadapnr: %d\n", adap->hwadapnr);
}
return NULL;
}
U_BOOT_I2C_ADAP_COMPLETE(davinci_0, davinci_i2c_init, davinci_i2c_probe,
davinci_i2c_read, davinci_i2c_write,
davinci_i2c_setspeed,
CONFIG_SYS_DAVINCI_I2C_SPEED,
CONFIG_SYS_DAVINCI_I2C_SLAVE,
0)
#if I2C_BUS_MAX >= 2
U_BOOT_I2C_ADAP_COMPLETE(davinci_1, davinci_i2c_init, davinci_i2c_probe,
davinci_i2c_read, davinci_i2c_write,
davinci_i2c_setspeed,
CONFIG_SYS_DAVINCI_I2C_SPEED1,
CONFIG_SYS_DAVINCI_I2C_SLAVE1,
1)
#endif
#if I2C_BUS_MAX >= 3
U_BOOT_I2C_ADAP_COMPLETE(davinci_2, davinci_i2c_init, davinci_i2c_probe,
davinci_i2c_read, davinci_i2c_write,
davinci_i2c_setspeed,
CONFIG_SYS_DAVINCI_I2C_SPEED2,
CONFIG_SYS_DAVINCI_I2C_SLAVE2,
2)
#endif