mirror of https://gitee.com/openkylin/linux.git
1039 lines
22 KiB
C
1039 lines
22 KiB
C
/*
|
|
* i2c_adap_pxa.c
|
|
*
|
|
* I2C adapter for the PXA I2C bus access.
|
|
*
|
|
* Copyright (C) 2002 Intrinsyc Software Inc.
|
|
* Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* History:
|
|
* Apr 2002: Initial version [CS]
|
|
* Jun 2002: Properly seperated algo/adap [FB]
|
|
* Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
|
|
* Jan 2003: added limited signal handling [Kai-Uwe Bloem]
|
|
* Sep 2004: Major rework to ensure efficient bus handling [RMK]
|
|
* Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
|
|
* Feb 2005: Rework slave mode handling [RMK]
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/i2c-id.h>
|
|
#include <linux/init.h>
|
|
#include <linux/time.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/i2c-pxa.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#include <asm/hardware.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/arch/i2c.h>
|
|
#include <asm/arch/pxa-regs.h>
|
|
|
|
struct pxa_i2c {
|
|
spinlock_t lock;
|
|
wait_queue_head_t wait;
|
|
struct i2c_msg *msg;
|
|
unsigned int msg_num;
|
|
unsigned int msg_idx;
|
|
unsigned int msg_ptr;
|
|
unsigned int slave_addr;
|
|
|
|
struct i2c_adapter adap;
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
struct i2c_slave_client *slave;
|
|
#endif
|
|
|
|
unsigned int irqlogidx;
|
|
u32 isrlog[32];
|
|
u32 icrlog[32];
|
|
};
|
|
|
|
/*
|
|
* I2C Slave mode address
|
|
*/
|
|
#define I2C_PXA_SLAVE_ADDR 0x1
|
|
|
|
#ifdef DEBUG
|
|
|
|
struct bits {
|
|
u32 mask;
|
|
const char *set;
|
|
const char *unset;
|
|
};
|
|
#define BIT(m, s, u) { .mask = m, .set = s, .unset = u }
|
|
|
|
static inline void
|
|
decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
|
|
{
|
|
printk("%s %08x: ", prefix, val);
|
|
while (num--) {
|
|
const char *str = val & bits->mask ? bits->set : bits->unset;
|
|
if (str)
|
|
printk("%s ", str);
|
|
bits++;
|
|
}
|
|
}
|
|
|
|
static const struct bits isr_bits[] = {
|
|
BIT(ISR_RWM, "RX", "TX"),
|
|
BIT(ISR_ACKNAK, "NAK", "ACK"),
|
|
BIT(ISR_UB, "Bsy", "Rdy"),
|
|
BIT(ISR_IBB, "BusBsy", "BusRdy"),
|
|
BIT(ISR_SSD, "SlaveStop", NULL),
|
|
BIT(ISR_ALD, "ALD", NULL),
|
|
BIT(ISR_ITE, "TxEmpty", NULL),
|
|
BIT(ISR_IRF, "RxFull", NULL),
|
|
BIT(ISR_GCAD, "GenCall", NULL),
|
|
BIT(ISR_SAD, "SlaveAddr", NULL),
|
|
BIT(ISR_BED, "BusErr", NULL),
|
|
};
|
|
|
|
static void decode_ISR(unsigned int val)
|
|
{
|
|
decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
|
|
printk("\n");
|
|
}
|
|
|
|
static const struct bits icr_bits[] = {
|
|
BIT(ICR_START, "START", NULL),
|
|
BIT(ICR_STOP, "STOP", NULL),
|
|
BIT(ICR_ACKNAK, "ACKNAK", NULL),
|
|
BIT(ICR_TB, "TB", NULL),
|
|
BIT(ICR_MA, "MA", NULL),
|
|
BIT(ICR_SCLE, "SCLE", "scle"),
|
|
BIT(ICR_IUE, "IUE", "iue"),
|
|
BIT(ICR_GCD, "GCD", NULL),
|
|
BIT(ICR_ITEIE, "ITEIE", NULL),
|
|
BIT(ICR_IRFIE, "IRFIE", NULL),
|
|
BIT(ICR_BEIE, "BEIE", NULL),
|
|
BIT(ICR_SSDIE, "SSDIE", NULL),
|
|
BIT(ICR_ALDIE, "ALDIE", NULL),
|
|
BIT(ICR_SADIE, "SADIE", NULL),
|
|
BIT(ICR_UR, "UR", "ur"),
|
|
};
|
|
|
|
static void decode_ICR(unsigned int val)
|
|
{
|
|
decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
|
|
printk("\n");
|
|
}
|
|
|
|
static unsigned int i2c_debug = DEBUG;
|
|
|
|
static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
|
|
{
|
|
dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno, ISR, ICR, IBMR);
|
|
}
|
|
|
|
#define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __FUNCTION__)
|
|
#else
|
|
#define i2c_debug 0
|
|
|
|
#define show_state(i2c) do { } while (0)
|
|
#define decode_ISR(val) do { } while (0)
|
|
#define decode_ICR(val) do { } while (0)
|
|
#endif
|
|
|
|
#define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
|
|
|
|
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
|
|
|
|
static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
|
|
{
|
|
unsigned int i;
|
|
printk("i2c: error: %s\n", why);
|
|
printk("i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
|
|
i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
|
|
printk("i2c: ICR: %08x ISR: %08x\n"
|
|
"i2c: log: ", ICR, ISR);
|
|
for (i = 0; i < i2c->irqlogidx; i++)
|
|
printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
|
|
printk("\n");
|
|
}
|
|
|
|
static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
|
|
{
|
|
return !(ICR & ICR_SCLE);
|
|
}
|
|
|
|
static void i2c_pxa_abort(struct pxa_i2c *i2c)
|
|
{
|
|
unsigned long timeout = jiffies + HZ/4;
|
|
|
|
if (i2c_pxa_is_slavemode(i2c)) {
|
|
dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
|
|
return;
|
|
}
|
|
|
|
while (time_before(jiffies, timeout) && (IBMR & 0x1) == 0) {
|
|
unsigned long icr = ICR;
|
|
|
|
icr &= ~ICR_START;
|
|
icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
|
|
|
|
ICR = icr;
|
|
|
|
show_state(i2c);
|
|
|
|
msleep(1);
|
|
}
|
|
|
|
ICR &= ~(ICR_MA | ICR_START | ICR_STOP);
|
|
}
|
|
|
|
static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
|
|
{
|
|
int timeout = DEF_TIMEOUT;
|
|
|
|
while (timeout-- && ISR & (ISR_IBB | ISR_UB)) {
|
|
if ((ISR & ISR_SAD) != 0)
|
|
timeout += 4;
|
|
|
|
msleep(2);
|
|
show_state(i2c);
|
|
}
|
|
|
|
if (timeout <= 0)
|
|
show_state(i2c);
|
|
|
|
return timeout <= 0 ? I2C_RETRY : 0;
|
|
}
|
|
|
|
static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
|
|
{
|
|
unsigned long timeout = jiffies + HZ*4;
|
|
|
|
while (time_before(jiffies, timeout)) {
|
|
if (i2c_debug > 1)
|
|
dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
|
|
__func__, (long)jiffies, ISR, ICR, IBMR);
|
|
|
|
if (ISR & ISR_SAD) {
|
|
if (i2c_debug > 0)
|
|
dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
|
|
goto out;
|
|
}
|
|
|
|
/* wait for unit and bus being not busy, and we also do a
|
|
* quick check of the i2c lines themselves to ensure they've
|
|
* gone high...
|
|
*/
|
|
if ((ISR & (ISR_UB | ISR_IBB)) == 0 && IBMR == 3) {
|
|
if (i2c_debug > 0)
|
|
dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
|
|
return 1;
|
|
}
|
|
|
|
msleep(1);
|
|
}
|
|
|
|
if (i2c_debug > 0)
|
|
dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
static int i2c_pxa_set_master(struct pxa_i2c *i2c)
|
|
{
|
|
if (i2c_debug)
|
|
dev_dbg(&i2c->adap.dev, "setting to bus master\n");
|
|
|
|
if ((ISR & (ISR_UB | ISR_IBB)) != 0) {
|
|
dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
|
|
if (!i2c_pxa_wait_master(i2c)) {
|
|
dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
|
|
return I2C_RETRY;
|
|
}
|
|
}
|
|
|
|
ICR |= ICR_SCLE;
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
|
|
{
|
|
unsigned long timeout = jiffies + HZ*1;
|
|
|
|
/* wait for stop */
|
|
|
|
show_state(i2c);
|
|
|
|
while (time_before(jiffies, timeout)) {
|
|
if (i2c_debug > 1)
|
|
dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
|
|
__func__, (long)jiffies, ISR, ICR, IBMR);
|
|
|
|
if ((ISR & (ISR_UB|ISR_IBB|ISR_SAD)) == ISR_SAD ||
|
|
(ICR & ICR_SCLE) == 0) {
|
|
if (i2c_debug > 1)
|
|
dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
|
|
return 1;
|
|
}
|
|
|
|
msleep(1);
|
|
}
|
|
|
|
if (i2c_debug > 0)
|
|
dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* clear the hold on the bus, and take of anything else
|
|
* that has been configured
|
|
*/
|
|
static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
|
|
{
|
|
show_state(i2c);
|
|
|
|
if (errcode < 0) {
|
|
udelay(100); /* simple delay */
|
|
} else {
|
|
/* we need to wait for the stop condition to end */
|
|
|
|
/* if we where in stop, then clear... */
|
|
if (ICR & ICR_STOP) {
|
|
udelay(100);
|
|
ICR &= ~ICR_STOP;
|
|
}
|
|
|
|
if (!i2c_pxa_wait_slave(i2c)) {
|
|
dev_err(&i2c->adap.dev, "%s: wait timedout\n",
|
|
__func__);
|
|
return;
|
|
}
|
|
}
|
|
|
|
ICR &= ~(ICR_STOP|ICR_ACKNAK|ICR_MA);
|
|
ICR &= ~ICR_SCLE;
|
|
|
|
if (i2c_debug) {
|
|
dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", ICR, ISR);
|
|
decode_ICR(ICR);
|
|
}
|
|
}
|
|
#else
|
|
#define i2c_pxa_set_slave(i2c, err) do { } while (0)
|
|
#endif
|
|
|
|
static void i2c_pxa_reset(struct pxa_i2c *i2c)
|
|
{
|
|
pr_debug("Resetting I2C Controller Unit\n");
|
|
|
|
/* abort any transfer currently under way */
|
|
i2c_pxa_abort(i2c);
|
|
|
|
/* reset according to 9.8 */
|
|
ICR = ICR_UR;
|
|
ISR = I2C_ISR_INIT;
|
|
ICR &= ~ICR_UR;
|
|
|
|
ISAR = i2c->slave_addr;
|
|
|
|
/* set control register values */
|
|
ICR = I2C_ICR_INIT;
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
dev_info(&i2c->adap.dev, "Enabling slave mode\n");
|
|
ICR |= ICR_SADIE | ICR_ALDIE | ICR_SSDIE;
|
|
#endif
|
|
|
|
i2c_pxa_set_slave(i2c, 0);
|
|
|
|
/* enable unit */
|
|
ICR |= ICR_IUE;
|
|
udelay(100);
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
/*
|
|
* I2C EEPROM emulation.
|
|
*/
|
|
static struct i2c_eeprom_emu eeprom = {
|
|
.size = I2C_EEPROM_EMU_SIZE,
|
|
.watch = LIST_HEAD_INIT(eeprom.watch),
|
|
};
|
|
|
|
struct i2c_eeprom_emu *i2c_pxa_get_eeprom(void)
|
|
{
|
|
return &eeprom;
|
|
}
|
|
|
|
int i2c_eeprom_emu_addwatcher(struct i2c_eeprom_emu *emu, void *data,
|
|
unsigned int addr, unsigned int size,
|
|
struct i2c_eeprom_emu_watcher *watcher)
|
|
{
|
|
struct i2c_eeprom_emu_watch *watch;
|
|
unsigned long flags;
|
|
|
|
if (addr + size > emu->size)
|
|
return -EINVAL;
|
|
|
|
watch = kmalloc(sizeof(struct i2c_eeprom_emu_watch), GFP_KERNEL);
|
|
if (watch) {
|
|
watch->start = addr;
|
|
watch->end = addr + size - 1;
|
|
watch->ops = watcher;
|
|
watch->data = data;
|
|
|
|
local_irq_save(flags);
|
|
list_add(&watch->node, &emu->watch);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
return watch ? 0 : -ENOMEM;
|
|
}
|
|
|
|
void i2c_eeprom_emu_delwatcher(struct i2c_eeprom_emu *emu, void *data,
|
|
struct i2c_eeprom_emu_watcher *watcher)
|
|
{
|
|
struct i2c_eeprom_emu_watch *watch, *n;
|
|
unsigned long flags;
|
|
|
|
list_for_each_entry_safe(watch, n, &emu->watch, node) {
|
|
if (watch->ops == watcher && watch->data == data) {
|
|
local_irq_save(flags);
|
|
list_del(&watch->node);
|
|
local_irq_restore(flags);
|
|
kfree(watch);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void i2c_eeprom_emu_event(void *ptr, i2c_slave_event_t event)
|
|
{
|
|
struct i2c_eeprom_emu *emu = ptr;
|
|
|
|
eedbg(3, "i2c_eeprom_emu_event: %d\n", event);
|
|
|
|
switch (event) {
|
|
case I2C_SLAVE_EVENT_START_WRITE:
|
|
emu->seen_start = 1;
|
|
eedbg(2, "i2c_eeprom: write initiated\n");
|
|
break;
|
|
|
|
case I2C_SLAVE_EVENT_START_READ:
|
|
emu->seen_start = 0;
|
|
eedbg(2, "i2c_eeprom: read initiated\n");
|
|
break;
|
|
|
|
case I2C_SLAVE_EVENT_STOP:
|
|
emu->seen_start = 0;
|
|
eedbg(2, "i2c_eeprom: received stop\n");
|
|
break;
|
|
|
|
default:
|
|
eedbg(0, "i2c_eeprom: unhandled event\n");
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int i2c_eeprom_emu_read(void *ptr)
|
|
{
|
|
struct i2c_eeprom_emu *emu = ptr;
|
|
int ret;
|
|
|
|
ret = emu->bytes[emu->ptr];
|
|
emu->ptr = (emu->ptr + 1) % emu->size;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void i2c_eeprom_emu_write(void *ptr, unsigned int val)
|
|
{
|
|
struct i2c_eeprom_emu *emu = ptr;
|
|
struct i2c_eeprom_emu_watch *watch;
|
|
|
|
if (emu->seen_start != 0) {
|
|
eedbg(2, "i2c_eeprom_emu_write: setting ptr %02x\n", val);
|
|
emu->ptr = val;
|
|
emu->seen_start = 0;
|
|
return;
|
|
}
|
|
|
|
emu->bytes[emu->ptr] = val;
|
|
|
|
eedbg(1, "i2c_eeprom_emu_write: ptr=0x%02x, val=0x%02x\n",
|
|
emu->ptr, val);
|
|
|
|
list_for_each_entry(watch, &emu->watch, node) {
|
|
if (!watch->ops || !watch->ops->write)
|
|
continue;
|
|
if (watch->start <= emu->ptr && watch->end >= emu->ptr)
|
|
watch->ops->write(watch->data, emu->ptr, val);
|
|
}
|
|
|
|
emu->ptr = (emu->ptr + 1) % emu->size;
|
|
}
|
|
|
|
struct i2c_slave_client eeprom_client = {
|
|
.data = &eeprom,
|
|
.event = i2c_eeprom_emu_event,
|
|
.read = i2c_eeprom_emu_read,
|
|
.write = i2c_eeprom_emu_write
|
|
};
|
|
|
|
/*
|
|
* PXA I2C Slave mode
|
|
*/
|
|
|
|
static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
if (isr & ISR_BED) {
|
|
/* what should we do here? */
|
|
} else {
|
|
int ret = i2c->slave->read(i2c->slave->data);
|
|
|
|
IDBR = ret;
|
|
ICR |= ICR_TB; /* allow next byte */
|
|
}
|
|
}
|
|
|
|
static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
unsigned int byte = IDBR;
|
|
|
|
if (i2c->slave != NULL)
|
|
i2c->slave->write(i2c->slave->data, byte);
|
|
|
|
ICR |= ICR_TB;
|
|
}
|
|
|
|
static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
int timeout;
|
|
|
|
if (i2c_debug > 0)
|
|
dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
|
|
(isr & ISR_RWM) ? 'r' : 't');
|
|
|
|
if (i2c->slave != NULL)
|
|
i2c->slave->event(i2c->slave->data,
|
|
(isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
|
|
|
|
/*
|
|
* slave could interrupt in the middle of us generating a
|
|
* start condition... if this happens, we'd better back off
|
|
* and stop holding the poor thing up
|
|
*/
|
|
ICR &= ~(ICR_START|ICR_STOP);
|
|
ICR |= ICR_TB;
|
|
|
|
timeout = 0x10000;
|
|
|
|
while (1) {
|
|
if ((IBMR & 2) == 2)
|
|
break;
|
|
|
|
timeout--;
|
|
|
|
if (timeout <= 0) {
|
|
dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
|
|
break;
|
|
}
|
|
}
|
|
|
|
ICR &= ~ICR_SCLE;
|
|
}
|
|
|
|
static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
|
|
{
|
|
if (i2c_debug > 2)
|
|
dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
|
|
|
|
if (i2c->slave != NULL)
|
|
i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
|
|
|
|
if (i2c_debug > 2)
|
|
dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
|
|
|
|
/*
|
|
* If we have a master-mode message waiting,
|
|
* kick it off now that the slave has completed.
|
|
*/
|
|
if (i2c->msg)
|
|
i2c_pxa_master_complete(i2c, I2C_RETRY);
|
|
}
|
|
#else
|
|
static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
if (isr & ISR_BED) {
|
|
/* what should we do here? */
|
|
} else {
|
|
IDBR = 0;
|
|
ICR |= ICR_TB;
|
|
}
|
|
}
|
|
|
|
static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
ICR |= ICR_TB | ICR_ACKNAK;
|
|
}
|
|
|
|
static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
int timeout;
|
|
|
|
/*
|
|
* slave could interrupt in the middle of us generating a
|
|
* start condition... if this happens, we'd better back off
|
|
* and stop holding the poor thing up
|
|
*/
|
|
ICR &= ~(ICR_START|ICR_STOP);
|
|
ICR |= ICR_TB | ICR_ACKNAK;
|
|
|
|
timeout = 0x10000;
|
|
|
|
while (1) {
|
|
if ((IBMR & 2) == 2)
|
|
break;
|
|
|
|
timeout--;
|
|
|
|
if (timeout <= 0) {
|
|
dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
|
|
break;
|
|
}
|
|
}
|
|
|
|
ICR &= ~ICR_SCLE;
|
|
}
|
|
|
|
static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
|
|
{
|
|
if (i2c->msg)
|
|
i2c_pxa_master_complete(i2c, I2C_RETRY);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* PXA I2C Master mode
|
|
*/
|
|
|
|
static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
|
|
{
|
|
unsigned int addr = (msg->addr & 0x7f) << 1;
|
|
|
|
if (msg->flags & I2C_M_RD)
|
|
addr |= 1;
|
|
|
|
return addr;
|
|
}
|
|
|
|
static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
|
|
{
|
|
u32 icr;
|
|
|
|
/*
|
|
* Step 1: target slave address into IDBR
|
|
*/
|
|
IDBR = i2c_pxa_addr_byte(i2c->msg);
|
|
|
|
/*
|
|
* Step 2: initiate the write.
|
|
*/
|
|
icr = ICR & ~(ICR_STOP | ICR_ALDIE);
|
|
ICR = icr | ICR_START | ICR_TB;
|
|
}
|
|
|
|
/*
|
|
* We are protected by the adapter bus mutex.
|
|
*/
|
|
static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
|
|
{
|
|
long timeout;
|
|
int ret;
|
|
|
|
/*
|
|
* Wait for the bus to become free.
|
|
*/
|
|
ret = i2c_pxa_wait_bus_not_busy(i2c);
|
|
if (ret) {
|
|
dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Set master mode.
|
|
*/
|
|
ret = i2c_pxa_set_master(i2c);
|
|
if (ret) {
|
|
dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
|
|
goto out;
|
|
}
|
|
|
|
spin_lock_irq(&i2c->lock);
|
|
|
|
i2c->msg = msg;
|
|
i2c->msg_num = num;
|
|
i2c->msg_idx = 0;
|
|
i2c->msg_ptr = 0;
|
|
i2c->irqlogidx = 0;
|
|
|
|
i2c_pxa_start_message(i2c);
|
|
|
|
spin_unlock_irq(&i2c->lock);
|
|
|
|
/*
|
|
* The rest of the processing occurs in the interrupt handler.
|
|
*/
|
|
timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
|
|
|
|
/*
|
|
* We place the return code in i2c->msg_idx.
|
|
*/
|
|
ret = i2c->msg_idx;
|
|
|
|
if (timeout == 0)
|
|
i2c_pxa_scream_blue_murder(i2c, "timeout");
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* i2c_pxa_master_complete - complete the message and wake up.
|
|
*/
|
|
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
|
|
{
|
|
i2c->msg_ptr = 0;
|
|
i2c->msg = NULL;
|
|
i2c->msg_idx ++;
|
|
i2c->msg_num = 0;
|
|
if (ret)
|
|
i2c->msg_idx = ret;
|
|
wake_up(&i2c->wait);
|
|
}
|
|
|
|
static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
u32 icr = ICR & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
|
|
|
|
again:
|
|
/*
|
|
* If ISR_ALD is set, we lost arbitration.
|
|
*/
|
|
if (isr & ISR_ALD) {
|
|
/*
|
|
* Do we need to do anything here? The PXA docs
|
|
* are vague about what happens.
|
|
*/
|
|
i2c_pxa_scream_blue_murder(i2c, "ALD set");
|
|
|
|
/*
|
|
* We ignore this error. We seem to see spurious ALDs
|
|
* for seemingly no reason. If we handle them as I think
|
|
* they should, we end up causing an I2C error, which
|
|
* is painful for some systems.
|
|
*/
|
|
return; /* ignore */
|
|
}
|
|
|
|
if (isr & ISR_BED) {
|
|
int ret = BUS_ERROR;
|
|
|
|
/*
|
|
* I2C bus error - either the device NAK'd us, or
|
|
* something more serious happened. If we were NAK'd
|
|
* on the initial address phase, we can retry.
|
|
*/
|
|
if (isr & ISR_ACKNAK) {
|
|
if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
|
|
ret = I2C_RETRY;
|
|
else
|
|
ret = XFER_NAKED;
|
|
}
|
|
i2c_pxa_master_complete(i2c, ret);
|
|
} else if (isr & ISR_RWM) {
|
|
/*
|
|
* Read mode. We have just sent the address byte, and
|
|
* now we must initiate the transfer.
|
|
*/
|
|
if (i2c->msg_ptr == i2c->msg->len - 1 &&
|
|
i2c->msg_idx == i2c->msg_num - 1)
|
|
icr |= ICR_STOP | ICR_ACKNAK;
|
|
|
|
icr |= ICR_ALDIE | ICR_TB;
|
|
} else if (i2c->msg_ptr < i2c->msg->len) {
|
|
/*
|
|
* Write mode. Write the next data byte.
|
|
*/
|
|
IDBR = i2c->msg->buf[i2c->msg_ptr++];
|
|
|
|
icr |= ICR_ALDIE | ICR_TB;
|
|
|
|
/*
|
|
* If this is the last byte of the last message, send
|
|
* a STOP.
|
|
*/
|
|
if (i2c->msg_ptr == i2c->msg->len &&
|
|
i2c->msg_idx == i2c->msg_num - 1)
|
|
icr |= ICR_STOP;
|
|
} else if (i2c->msg_idx < i2c->msg_num - 1) {
|
|
/*
|
|
* Next segment of the message.
|
|
*/
|
|
i2c->msg_ptr = 0;
|
|
i2c->msg_idx ++;
|
|
i2c->msg++;
|
|
|
|
/*
|
|
* If we aren't doing a repeated start and address,
|
|
* go back and try to send the next byte. Note that
|
|
* we do not support switching the R/W direction here.
|
|
*/
|
|
if (i2c->msg->flags & I2C_M_NOSTART)
|
|
goto again;
|
|
|
|
/*
|
|
* Write the next address.
|
|
*/
|
|
IDBR = i2c_pxa_addr_byte(i2c->msg);
|
|
|
|
/*
|
|
* And trigger a repeated start, and send the byte.
|
|
*/
|
|
icr &= ~ICR_ALDIE;
|
|
icr |= ICR_START | ICR_TB;
|
|
} else {
|
|
if (i2c->msg->len == 0) {
|
|
/*
|
|
* Device probes have a message length of zero
|
|
* and need the bus to be reset before it can
|
|
* be used again.
|
|
*/
|
|
i2c_pxa_reset(i2c);
|
|
}
|
|
i2c_pxa_master_complete(i2c, 0);
|
|
}
|
|
|
|
i2c->icrlog[i2c->irqlogidx-1] = icr;
|
|
|
|
ICR = icr;
|
|
show_state(i2c);
|
|
}
|
|
|
|
static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
u32 icr = ICR & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
|
|
|
|
/*
|
|
* Read the byte.
|
|
*/
|
|
i2c->msg->buf[i2c->msg_ptr++] = IDBR;
|
|
|
|
if (i2c->msg_ptr < i2c->msg->len) {
|
|
/*
|
|
* If this is the last byte of the last
|
|
* message, send a STOP.
|
|
*/
|
|
if (i2c->msg_ptr == i2c->msg->len - 1)
|
|
icr |= ICR_STOP | ICR_ACKNAK;
|
|
|
|
icr |= ICR_ALDIE | ICR_TB;
|
|
} else {
|
|
i2c_pxa_master_complete(i2c, 0);
|
|
}
|
|
|
|
i2c->icrlog[i2c->irqlogidx-1] = icr;
|
|
|
|
ICR = icr;
|
|
}
|
|
|
|
static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id, struct pt_regs *regs)
|
|
{
|
|
struct pxa_i2c *i2c = dev_id;
|
|
u32 isr = ISR;
|
|
|
|
if (i2c_debug > 2 && 0) {
|
|
dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
|
|
__func__, isr, ICR, IBMR);
|
|
decode_ISR(isr);
|
|
}
|
|
|
|
if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
|
|
i2c->isrlog[i2c->irqlogidx++] = isr;
|
|
|
|
show_state(i2c);
|
|
|
|
/*
|
|
* Always clear all pending IRQs.
|
|
*/
|
|
ISR = isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED);
|
|
|
|
if (isr & ISR_SAD)
|
|
i2c_pxa_slave_start(i2c, isr);
|
|
if (isr & ISR_SSD)
|
|
i2c_pxa_slave_stop(i2c);
|
|
|
|
if (i2c_pxa_is_slavemode(i2c)) {
|
|
if (isr & ISR_ITE)
|
|
i2c_pxa_slave_txempty(i2c, isr);
|
|
if (isr & ISR_IRF)
|
|
i2c_pxa_slave_rxfull(i2c, isr);
|
|
} else if (i2c->msg) {
|
|
if (isr & ISR_ITE)
|
|
i2c_pxa_irq_txempty(i2c, isr);
|
|
if (isr & ISR_IRF)
|
|
i2c_pxa_irq_rxfull(i2c, isr);
|
|
} else {
|
|
i2c_pxa_scream_blue_murder(i2c, "spurious irq");
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
|
|
static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
|
|
{
|
|
struct pxa_i2c *i2c = adap->algo_data;
|
|
int ret, i;
|
|
|
|
/* If the I2C controller is disabled we need to reset it (probably due
|
|
to a suspend/resume destroying state). We do this here as we can then
|
|
avoid worrying about resuming the controller before its users. */
|
|
if (!(ICR & ICR_IUE))
|
|
i2c_pxa_reset(i2c);
|
|
|
|
for (i = adap->retries; i >= 0; i--) {
|
|
ret = i2c_pxa_do_xfer(i2c, msgs, num);
|
|
if (ret != I2C_RETRY)
|
|
goto out;
|
|
|
|
if (i2c_debug)
|
|
dev_dbg(&adap->dev, "Retrying transmission\n");
|
|
udelay(100);
|
|
}
|
|
i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
|
|
ret = -EREMOTEIO;
|
|
out:
|
|
i2c_pxa_set_slave(i2c, ret);
|
|
return ret;
|
|
}
|
|
|
|
static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
|
|
{
|
|
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
|
|
}
|
|
|
|
static const struct i2c_algorithm i2c_pxa_algorithm = {
|
|
.master_xfer = i2c_pxa_xfer,
|
|
.functionality = i2c_pxa_functionality,
|
|
};
|
|
|
|
static struct pxa_i2c i2c_pxa = {
|
|
.lock = SPIN_LOCK_UNLOCKED,
|
|
.wait = __WAIT_QUEUE_HEAD_INITIALIZER(i2c_pxa.wait),
|
|
.adap = {
|
|
.owner = THIS_MODULE,
|
|
.algo = &i2c_pxa_algorithm,
|
|
.name = "pxa2xx-i2c",
|
|
.retries = 5,
|
|
},
|
|
};
|
|
|
|
static int i2c_pxa_probe(struct platform_device *dev)
|
|
{
|
|
struct pxa_i2c *i2c = &i2c_pxa;
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
|
|
#endif
|
|
int ret;
|
|
|
|
#ifdef CONFIG_PXA27x
|
|
pxa_gpio_mode(GPIO117_I2CSCL_MD);
|
|
pxa_gpio_mode(GPIO118_I2CSDA_MD);
|
|
udelay(100);
|
|
#endif
|
|
|
|
i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
i2c->slave = &eeprom_client;
|
|
if (plat) {
|
|
i2c->slave_addr = plat->slave_addr;
|
|
if (plat->slave)
|
|
i2c->slave = plat->slave;
|
|
}
|
|
#endif
|
|
|
|
pxa_set_cken(CKEN14_I2C, 1);
|
|
ret = request_irq(IRQ_I2C, i2c_pxa_handler, IRQF_DISABLED,
|
|
"pxa2xx-i2c", i2c);
|
|
if (ret)
|
|
goto out;
|
|
|
|
i2c_pxa_reset(i2c);
|
|
|
|
i2c->adap.algo_data = i2c;
|
|
i2c->adap.dev.parent = &dev->dev;
|
|
|
|
ret = i2c_add_adapter(&i2c->adap);
|
|
if (ret < 0) {
|
|
printk(KERN_INFO "I2C: Failed to add bus\n");
|
|
goto err_irq;
|
|
}
|
|
|
|
platform_set_drvdata(dev, i2c);
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
|
|
i2c->adap.dev.bus_id, i2c->slave_addr);
|
|
#else
|
|
printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
|
|
i2c->adap.dev.bus_id);
|
|
#endif
|
|
return 0;
|
|
|
|
err_irq:
|
|
free_irq(IRQ_I2C, i2c);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int i2c_pxa_remove(struct platform_device *dev)
|
|
{
|
|
struct pxa_i2c *i2c = platform_get_drvdata(dev);
|
|
|
|
platform_set_drvdata(dev, NULL);
|
|
|
|
i2c_del_adapter(&i2c->adap);
|
|
free_irq(IRQ_I2C, i2c);
|
|
pxa_set_cken(CKEN14_I2C, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver i2c_pxa_driver = {
|
|
.probe = i2c_pxa_probe,
|
|
.remove = i2c_pxa_remove,
|
|
.driver = {
|
|
.name = "pxa2xx-i2c",
|
|
},
|
|
};
|
|
|
|
static int __init i2c_adap_pxa_init(void)
|
|
{
|
|
return platform_driver_register(&i2c_pxa_driver);
|
|
}
|
|
|
|
static void i2c_adap_pxa_exit(void)
|
|
{
|
|
return platform_driver_unregister(&i2c_pxa_driver);
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(i2c_adap_pxa_init);
|
|
module_exit(i2c_adap_pxa_exit);
|