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u-boot/drivers/i2c/omap24xx_i2c.c

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/*
* Basic I2C functions
*
* Copyright (c) 2004 Texas Instruments
*
* This package is free software; you can redistribute it and/or
* modify it under the terms of the license found in the file
* named COPYING that should have accompanied this file.
*
* THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* Author: Jian Zhang jzhang@ti.com, Texas Instruments
*
* Copyright (c) 2003 Wolfgang Denk, wd@denx.de
* Rewritten to fit into the current U-Boot framework
*
* Adapted for OMAP2420 I2C, r-woodruff2@ti.com
*
* Copyright (c) 2013 Lubomir Popov <lpopov@mm-sol.com>, MM Solutions
* New i2c_read, i2c_write and i2c_probe functions, tested on OMAP4
* (4430/60/70), OMAP5 (5430) and AM335X (3359); should work on older
* OMAPs and derivatives as well. The only anticipated exception would
* be the OMAP2420, which shall require driver modification.
* - Rewritten i2c_read to operate correctly with all types of chips
* (old function could not read consistent data from some I2C slaves).
* - Optimized i2c_write.
* - New i2c_probe, performs write access vs read. The old probe could
* hang the system under certain conditions (e.g. unconfigured pads).
* - The read/write/probe functions try to identify unconfigured bus.
* - Status functions now read irqstatus_raw as per TRM guidelines
* (except for OMAP243X and OMAP34XX).
* - Driver now supports up to I2C5 (OMAP5).
*
* Copyright (c) 2014 Hannes Petermaier <oe5hpm@oevsv.at>, B&R
* - Added support for set_speed
*
*/
#include <common.h>
#include <i2c.h>
#include <asm/arch/i2c.h>
#include <asm/io.h>
#include "omap24xx_i2c.h"
DECLARE_GLOBAL_DATA_PTR;
#define I2C_TIMEOUT 1000
/* Absolutely safe for status update at 100 kHz I2C: */
#define I2C_WAIT 200
static int wait_for_bb(struct i2c_adapter *adap);
static struct i2c *omap24_get_base(struct i2c_adapter *adap);
static u16 wait_for_event(struct i2c_adapter *adap);
static void flush_fifo(struct i2c_adapter *adap);
static int omap24_i2c_findpsc(u32 *pscl, u32 *psch, uint speed)
{
unsigned int sampleclk, prescaler;
int fsscll, fssclh;
speed <<= 1;
prescaler = 0;
/*
* some divisors may cause a precission loss, but shouldn't
* be a big thing, because i2c_clk is then allready very slow.
*/
while (prescaler <= 0xFF) {
sampleclk = I2C_IP_CLK / (prescaler+1);
fsscll = sampleclk / speed;
fssclh = fsscll;
fsscll -= I2C_FASTSPEED_SCLL_TRIM;
fssclh -= I2C_FASTSPEED_SCLH_TRIM;
if (((fsscll > 0) && (fssclh > 0)) &&
((fsscll <= (255-I2C_FASTSPEED_SCLL_TRIM)) &&
(fssclh <= (255-I2C_FASTSPEED_SCLH_TRIM)))) {
if (pscl)
*pscl = fsscll;
if (psch)
*psch = fssclh;
return prescaler;
}
prescaler++;
}
return -1;
}
static uint omap24_i2c_setspeed(struct i2c_adapter *adap, uint speed)
{
struct i2c *i2c_base = omap24_get_base(adap);
int psc, fsscll = 0, fssclh = 0;
int hsscll = 0, hssclh = 0;
u32 scll = 0, sclh = 0;
if (speed >= OMAP_I2C_HIGH_SPEED) {
/* High speed */
psc = I2C_IP_CLK / I2C_INTERNAL_SAMPLING_CLK;
psc -= 1;
if (psc < I2C_PSC_MIN) {
printf("Error : I2C unsupported prescaler %d\n", psc);
return -1;
}
/* For first phase of HS mode */
fsscll = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
fssclh = fsscll;
fsscll -= I2C_HIGHSPEED_PHASE_ONE_SCLL_TRIM;
fssclh -= I2C_HIGHSPEED_PHASE_ONE_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
puts("Error : I2C initializing first phase clock\n");
return -1;
}
/* For second phase of HS mode */
hsscll = hssclh = I2C_INTERNAL_SAMPLING_CLK / (2 * speed);
hsscll -= I2C_HIGHSPEED_PHASE_TWO_SCLL_TRIM;
hssclh -= I2C_HIGHSPEED_PHASE_TWO_SCLH_TRIM;
if (((fsscll < 0) || (fssclh < 0)) ||
((fsscll > 255) || (fssclh > 255))) {
puts("Error : I2C initializing second phase clock\n");
return -1;
}
scll = (unsigned int)hsscll << 8 | (unsigned int)fsscll;
sclh = (unsigned int)hssclh << 8 | (unsigned int)fssclh;
} else {
/* Standard and fast speed */
psc = omap24_i2c_findpsc(&scll, &sclh, speed);
if (0 > psc) {
puts("Error : I2C initializing clock\n");
return -1;
}
}
adap->speed = speed;
adap->waitdelay = (10000000 / speed) * 2; /* wait for 20 clkperiods */
writew(0, &i2c_base->con);
writew(psc, &i2c_base->psc);
writew(scll, &i2c_base->scll);
writew(sclh, &i2c_base->sclh);
writew(I2C_CON_EN, &i2c_base->con);
writew(0xFFFF, &i2c_base->stat); /* clear all pending status */
return 0;
}
static void omap24_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
{
struct i2c *i2c_base = omap24_get_base(adap);
int timeout = I2C_TIMEOUT;
if (readw(&i2c_base->con) & I2C_CON_EN) {
writew(0, &i2c_base->con);
udelay(50000);
}
writew(0x2, &i2c_base->sysc); /* for ES2 after soft reset */
udelay(1000);
writew(I2C_CON_EN, &i2c_base->con);
while (!(readw(&i2c_base->syss) & I2C_SYSS_RDONE) && timeout--) {
if (timeout <= 0) {
puts("ERROR: Timeout in soft-reset\n");
return;
}
udelay(1000);
}
if (0 != omap24_i2c_setspeed(adap, speed)) {
printf("ERROR: failed to setup I2C bus-speed!\n");
return;
}
/* own address */
writew(slaveadd, &i2c_base->oa);
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
/*
* Have to enable interrupts for OMAP2/3, these IPs don't have
* an 'irqstatus_raw' register and we shall have to poll 'stat'
*/
writew(I2C_IE_XRDY_IE | I2C_IE_RRDY_IE | I2C_IE_ARDY_IE |
I2C_IE_NACK_IE | I2C_IE_AL_IE, &i2c_base->ie);
#endif
udelay(1000);
flush_fifo(adap);
writew(0xFFFF, &i2c_base->stat);
}
static void flush_fifo(struct i2c_adapter *adap)
{
struct i2c *i2c_base = omap24_get_base(adap);
u16 stat;
/*
* note: if you try and read data when its not there or ready
* you get a bus error
*/
while (1) {
stat = readw(&i2c_base->stat);
if (stat == I2C_STAT_RRDY) {
readb(&i2c_base->data);
writew(I2C_STAT_RRDY, &i2c_base->stat);
udelay(1000);
} else
break;
}
}
/*
* i2c_probe: Use write access. Allows to identify addresses that are
* write-only (like the config register of dual-port EEPROMs)
*/
static int omap24_i2c_probe(struct i2c_adapter *adap, uchar chip)
{
struct i2c *i2c_base = omap24_get_base(adap);
u16 status;
int res = 1; /* default = fail */
if (chip == readw(&i2c_base->oa))
return res;
/* Wait until bus is free */
if (wait_for_bb(adap))
return res;
/* No data transfer, slave addr only */
writew(chip, &i2c_base->sa);
/* Stop bit needed here */
writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
I2C_CON_STP, &i2c_base->con);
status = wait_for_event(adap);
if ((status & ~I2C_STAT_XRDY) == 0 || (status & I2C_STAT_AL)) {
/*
* With current high-level command implementation, notifying
* the user shall flood the console with 127 messages. If
* silent exit is desired upon unconfigured bus, remove the
* following 'if' section:
*/
if (status == I2C_STAT_XRDY)
printf("i2c_probe: pads on bus %d probably not configured (status=0x%x)\n",
adap->hwadapnr, status);
goto pr_exit;
}
/* Check for ACK (!NAK) */
if (!(status & I2C_STAT_NACK)) {
res = 0; /* Device found */
udelay(adap->waitdelay);/* Required by AM335X in SPL */
/* Abort transfer (force idle state) */
writew(I2C_CON_MST | I2C_CON_TRX, &i2c_base->con); /* Reset */
udelay(1000);
writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_TRX |
I2C_CON_STP, &i2c_base->con); /* STP */
}
pr_exit:
flush_fifo(adap);
writew(0xFFFF, &i2c_base->stat);
return res;
}
/*
* i2c_read: Function now uses a single I2C read transaction with bulk transfer
* of the requested number of bytes (note that the 'i2c md' command
* limits this to 16 bytes anyway). If CONFIG_I2C_REPEATED_START is
* defined in the board config header, this transaction shall be with
* Repeated Start (Sr) between the address and data phases; otherwise
* Stop-Start (P-S) shall be used (some I2C chips do require a P-S).
* The address (reg offset) may be 0, 1 or 2 bytes long.
* Function now reads correctly from chips that return more than one
* byte of data per addressed register (like TI temperature sensors),
* or that do not need a register address at all (such as some clock
* distributors).
*/
static int omap24_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *buffer, int len)
{
struct i2c *i2c_base = omap24_get_base(adap);
int i2c_error = 0;
u16 status;
if (alen < 0) {
puts("I2C read: addr len < 0\n");
return 1;
}
if (len < 0) {
puts("I2C read: data len < 0\n");
return 1;
}
if (buffer == NULL) {
puts("I2C read: NULL pointer passed\n");
return 1;
}
if (alen > 2) {
printf("I2C read: addr len %d not supported\n", alen);
return 1;
}
if (addr + len > (1 << 16)) {
puts("I2C read: address out of range\n");
return 1;
}
/* Wait until bus not busy */
if (wait_for_bb(adap))
return 1;
/* Zero, one or two bytes reg address (offset) */
writew(alen, &i2c_base->cnt);
/* Set slave address */
writew(chip, &i2c_base->sa);
if (alen) {
/* Must write reg offset first */
#ifdef CONFIG_I2C_REPEATED_START
/* No stop bit, use Repeated Start (Sr) */
writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT |
I2C_CON_TRX, &i2c_base->con);
#else
/* Stop - Start (P-S) */
writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_STP |
I2C_CON_TRX, &i2c_base->con);
#endif
/* Send register offset */
while (1) {
status = wait_for_event(adap);
/* Try to identify bus that is not padconf'd for I2C */
if (status == I2C_STAT_XRDY) {
i2c_error = 2;
printf("i2c_read (addr phase): pads on bus %d probably not configured (status=0x%x)\n",
adap->hwadapnr, status);
goto rd_exit;
}
if (status == 0 || (status & I2C_STAT_NACK)) {
i2c_error = 1;
printf("i2c_read: error waiting for addr ACK (status=0x%x)\n",
status);
goto rd_exit;
}
if (alen) {
if (status & I2C_STAT_XRDY) {
alen--;
/* Do we have to use byte access? */
writeb((addr >> (8 * alen)) & 0xff,
&i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
}
}
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
}
}
/* Set slave address */
writew(chip, &i2c_base->sa);
/* Read len bytes from slave */
writew(len, &i2c_base->cnt);
/* Need stop bit here */
writew(I2C_CON_EN | I2C_CON_MST |
I2C_CON_STT | I2C_CON_STP,
&i2c_base->con);
/* Receive data */
while (1) {
status = wait_for_event(adap);
/*
* Try to identify bus that is not padconf'd for I2C. This
* state could be left over from previous transactions if
* the address phase is skipped due to alen=0.
*/
if (status == I2C_STAT_XRDY) {
i2c_error = 2;
printf("i2c_read (data phase): pads on bus %d probably not configured (status=0x%x)\n",
adap->hwadapnr, status);
goto rd_exit;
}
if (status == 0 || (status & I2C_STAT_NACK)) {
i2c_error = 1;
goto rd_exit;
}
if (status & I2C_STAT_RRDY) {
*buffer++ = readb(&i2c_base->data);
writew(I2C_STAT_RRDY, &i2c_base->stat);
}
if (status & I2C_STAT_ARDY) {
writew(I2C_STAT_ARDY, &i2c_base->stat);
break;
}
}
rd_exit:
flush_fifo(adap);
writew(0xFFFF, &i2c_base->stat);
return i2c_error;
}
/* i2c_write: Address (reg offset) may be 0, 1 or 2 bytes long. */
static int omap24_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
int alen, uchar *buffer, int len)
{
struct i2c *i2c_base = omap24_get_base(adap);
int i;
u16 status;
int i2c_error = 0;
int timeout = I2C_TIMEOUT;
if (alen < 0) {
puts("I2C write: addr len < 0\n");
return 1;
}
if (len < 0) {
puts("I2C write: data len < 0\n");
return 1;
}
if (buffer == NULL) {
puts("I2C write: NULL pointer passed\n");
return 1;
}
if (alen > 2) {
printf("I2C write: addr len %d not supported\n", alen);
return 1;
}
if (addr + len > (1 << 16)) {
printf("I2C write: address 0x%x + 0x%x out of range\n",
addr, len);
return 1;
}
/* Wait until bus not busy */
if (wait_for_bb(adap))
return 1;
/* Start address phase - will write regoffset + len bytes data */
writew(alen + len, &i2c_base->cnt);
/* Set slave address */
writew(chip, &i2c_base->sa);
/* Stop bit needed here */
writew(I2C_CON_EN | I2C_CON_MST | I2C_CON_STT | I2C_CON_TRX |
I2C_CON_STP, &i2c_base->con);
while (alen) {
/* Must write reg offset (one or two bytes) */
status = wait_for_event(adap);
/* Try to identify bus that is not padconf'd for I2C */
if (status == I2C_STAT_XRDY) {
i2c_error = 2;
printf("i2c_write: pads on bus %d probably not configured (status=0x%x)\n",
adap->hwadapnr, status);
goto wr_exit;
}
if (status == 0 || (status & I2C_STAT_NACK)) {
i2c_error = 1;
printf("i2c_write: error waiting for addr ACK (status=0x%x)\n",
status);
goto wr_exit;
}
if (status & I2C_STAT_XRDY) {
alen--;
writeb((addr >> (8 * alen)) & 0xff, &i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
} else {
i2c_error = 1;
printf("i2c_write: bus not ready for addr Tx (status=0x%x)\n",
status);
goto wr_exit;
}
}
/* Address phase is over, now write data */
for (i = 0; i < len; i++) {
status = wait_for_event(adap);
if (status == 0 || (status & I2C_STAT_NACK)) {
i2c_error = 1;
printf("i2c_write: error waiting for data ACK (status=0x%x)\n",
status);
goto wr_exit;
}
if (status & I2C_STAT_XRDY) {
writeb(buffer[i], &i2c_base->data);
writew(I2C_STAT_XRDY, &i2c_base->stat);
} else {
i2c_error = 1;
printf("i2c_write: bus not ready for data Tx (i=%d)\n",
i);
goto wr_exit;
}
}
/*
* poll ARDY bit for making sure that last byte really has been
* transferred on the bus.
*/
do {
status = wait_for_event(adap);
} while (!(status & I2C_STAT_ARDY) && timeout--);
if (timeout <= 0)
printf("i2c_write: timed out writig last byte!\n");
wr_exit:
flush_fifo(adap);
writew(0xFFFF, &i2c_base->stat);
return i2c_error;
}
/*
* Wait for the bus to be free by checking the Bus Busy (BB)
* bit to become clear
*/
static int wait_for_bb(struct i2c_adapter *adap)
{
struct i2c *i2c_base = omap24_get_base(adap);
int timeout = I2C_TIMEOUT;
u16 stat;
writew(0xFFFF, &i2c_base->stat); /* clear current interrupts...*/
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
while ((stat = readw(&i2c_base->stat) & I2C_STAT_BB) && timeout--) {
#else
/* Read RAW status */
while ((stat = readw(&i2c_base->irqstatus_raw) &
I2C_STAT_BB) && timeout--) {
#endif
writew(stat, &i2c_base->stat);
udelay(adap->waitdelay);
}
if (timeout <= 0) {
printf("Timed out in wait_for_bb: status=%04x\n",
stat);
return 1;
}
writew(0xFFFF, &i2c_base->stat); /* clear delayed stuff*/
return 0;
}
/*
* Wait for the I2C controller to complete current action
* and update status
*/
static u16 wait_for_event(struct i2c_adapter *adap)
{
struct i2c *i2c_base = omap24_get_base(adap);
u16 status;
int timeout = I2C_TIMEOUT;
do {
udelay(adap->waitdelay);
#if defined(CONFIG_OMAP243X) || defined(CONFIG_OMAP34XX)
status = readw(&i2c_base->stat);
#else
/* Read RAW status */
status = readw(&i2c_base->irqstatus_raw);
#endif
} while (!(status &
(I2C_STAT_ROVR | I2C_STAT_XUDF | I2C_STAT_XRDY |
I2C_STAT_RRDY | I2C_STAT_ARDY | I2C_STAT_NACK |
I2C_STAT_AL)) && timeout--);
if (timeout <= 0) {
printf("Timed out in wait_for_event: status=%04x\n",
status);
/*
* If status is still 0 here, probably the bus pads have
* not been configured for I2C, and/or pull-ups are missing.
*/
printf("Check if pads/pull-ups of bus %d are properly configured\n",
adap->hwadapnr);
writew(0xFFFF, &i2c_base->stat);
status = 0;
}
return status;
}
static struct i2c *omap24_get_base(struct i2c_adapter *adap)
{
switch (adap->hwadapnr) {
case 0:
return (struct i2c *)I2C_BASE1;
break;
case 1:
return (struct i2c *)I2C_BASE2;
break;
#if (I2C_BUS_MAX > 2)
case 2:
return (struct i2c *)I2C_BASE3;
break;
#if (I2C_BUS_MAX > 3)
case 3:
return (struct i2c *)I2C_BASE4;
break;
#if (I2C_BUS_MAX > 4)
case 4:
return (struct i2c *)I2C_BASE5;
break;
#endif
#endif
#endif
default:
printf("wrong hwadapnr: %d\n", adap->hwadapnr);
break;
}
return NULL;
}
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED1)
#define CONFIG_SYS_OMAP24_I2C_SPEED1 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE1)
#define CONFIG_SYS_OMAP24_I2C_SLAVE1 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif
U_BOOT_I2C_ADAP_COMPLETE(omap24_0, omap24_i2c_init, omap24_i2c_probe,
omap24_i2c_read, omap24_i2c_write, omap24_i2c_setspeed,
CONFIG_SYS_OMAP24_I2C_SPEED,
CONFIG_SYS_OMAP24_I2C_SLAVE,
0)
U_BOOT_I2C_ADAP_COMPLETE(omap24_1, omap24_i2c_init, omap24_i2c_probe,
omap24_i2c_read, omap24_i2c_write, omap24_i2c_setspeed,
CONFIG_SYS_OMAP24_I2C_SPEED1,
CONFIG_SYS_OMAP24_I2C_SLAVE1,
1)
#if (I2C_BUS_MAX > 2)
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED2)
#define CONFIG_SYS_OMAP24_I2C_SPEED2 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE2)
#define CONFIG_SYS_OMAP24_I2C_SLAVE2 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif
U_BOOT_I2C_ADAP_COMPLETE(omap24_2, omap24_i2c_init, omap24_i2c_probe,
omap24_i2c_read, omap24_i2c_write, NULL,
CONFIG_SYS_OMAP24_I2C_SPEED2,
CONFIG_SYS_OMAP24_I2C_SLAVE2,
2)
#if (I2C_BUS_MAX > 3)
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED3)
#define CONFIG_SYS_OMAP24_I2C_SPEED3 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE3)
#define CONFIG_SYS_OMAP24_I2C_SLAVE3 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif
U_BOOT_I2C_ADAP_COMPLETE(omap24_3, omap24_i2c_init, omap24_i2c_probe,
omap24_i2c_read, omap24_i2c_write, NULL,
CONFIG_SYS_OMAP24_I2C_SPEED3,
CONFIG_SYS_OMAP24_I2C_SLAVE3,
3)
#if (I2C_BUS_MAX > 4)
#if !defined(CONFIG_SYS_OMAP24_I2C_SPEED4)
#define CONFIG_SYS_OMAP24_I2C_SPEED4 CONFIG_SYS_OMAP24_I2C_SPEED
#endif
#if !defined(CONFIG_SYS_OMAP24_I2C_SLAVE4)
#define CONFIG_SYS_OMAP24_I2C_SLAVE4 CONFIG_SYS_OMAP24_I2C_SLAVE
#endif
U_BOOT_I2C_ADAP_COMPLETE(omap24_4, omap24_i2c_init, omap24_i2c_probe,
omap24_i2c_read, omap24_i2c_write, NULL,
CONFIG_SYS_OMAP24_I2C_SPEED4,
CONFIG_SYS_OMAP24_I2C_SLAVE4,
4)
#endif
#endif
#endif
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