--- /dev/null
+/*
+ * 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 <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 semaphore.
+ */
+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 < sizeof(i2c->isrlog)/sizeof(u32))
+ 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;
+
+ 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 struct i2c_algorithm i2c_pxa_algorithm = {
+ .name = "PXA-I2C-Algorithm",
+ .id = I2C_ALGO_PXA,
+ .master_xfer = i2c_pxa_xfer,
+};
+
+static struct pxa_i2c i2c_pxa = {
+ .lock = SPIN_LOCK_UNLOCKED,
+ .wait = __WAIT_QUEUE_HEAD_INITIALIZER(i2c_pxa.wait),
+ .adap = {
+ .name = "pxa2xx-i2c",
+ .id = I2C_ALGO_PXA,
+ .algo = &i2c_pxa_algorithm,
+ .retries = 5,
+ },
+};
+
+static int i2c_pxa_probe(struct device *dev)
+{
+ struct pxa_i2c *i2c = &i2c_pxa;
+ struct i2c_pxa_platform_data *plat = dev->platform_data;
+ 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, SA_INTERRUPT,
+ "pxa2xx-i2c", i2c);
+ if (ret)
+ goto out;
+
+ i2c_pxa_reset(i2c);
+
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = dev;
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret < 0) {
+ printk(KERN_INFO "I2C: Failed to add bus\n");
+ goto err_irq;
+ }
+
+ dev_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 device *dev)
+{
+ struct pxa_i2c *i2c = dev_get_drvdata(dev);
+
+ dev_set_drvdata(dev, NULL);
+
+ i2c_del_adapter(&i2c->adap);
+ free_irq(IRQ_I2C, i2c);
+ pxa_set_cken(CKEN14_I2C, 0);
+
+ return 0;
+}
+
+static struct device_driver i2c_pxa_driver = {
+ .name = "pxa2xx-i2c",
+ .bus = &platform_bus_type,
+ .probe = i2c_pxa_probe,
+ .remove = i2c_pxa_remove,
+};
+
+static int __init i2c_adap_pxa_init(void)
+{
+ return driver_register(&i2c_pxa_driver);
+}
+
+static void i2c_adap_pxa_exit(void)
+{
+ return driver_unregister(&i2c_pxa_driver);
+}
+
+module_init(i2c_adap_pxa_init);
+module_exit(i2c_adap_pxa_exit);
git.samba.org / sfrench / cifs-2.6.git / commitdiff