--- /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 separated 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/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/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/i2c/pxa-i2c.h>
+
+#include <asm/irq.h>
+
+struct pxa_reg_layout {
+ u32 ibmr;
+ u32 idbr;
+ u32 icr;
+ u32 isr;
+ u32 isar;
+};
+
+enum pxa_i2c_types {
+ REGS_PXA2XX,
+ REGS_PXA3XX,
+ REGS_CE4100,
+};
+
+/*
+ * I2C registers definitions
+ */
+static struct pxa_reg_layout pxa_reg_layout[] = {
+ [REGS_PXA2XX] = {
+ .ibmr = 0x00,
+ .idbr = 0x08,
+ .icr = 0x10,
+ .isr = 0x18,
+ .isar = 0x20,
+ },
+ [REGS_PXA3XX] = {
+ .ibmr = 0x00,
+ .idbr = 0x04,
+ .icr = 0x08,
+ .isr = 0x0c,
+ .isar = 0x10,
+ },
+ [REGS_CE4100] = {
+ .ibmr = 0x14,
+ .idbr = 0x0c,
+ .icr = 0x00,
+ .isr = 0x04,
+ /* no isar register */
+ },
+};
+
+static const struct platform_device_id i2c_pxa_id_table[] = {
+ { "pxa2xx-i2c", REGS_PXA2XX },
+ { "pxa3xx-pwri2c", REGS_PXA3XX },
+ { "ce4100-i2c", REGS_CE4100 },
+ { },
+};
+MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
+
+/*
+ * I2C bit definitions
+ */
+
+#define ICR_START (1 << 0) /* start bit */
+#define ICR_STOP (1 << 1) /* stop bit */
+#define ICR_ACKNAK (1 << 2) /* send ACK(0) or NAK(1) */
+#define ICR_TB (1 << 3) /* transfer byte bit */
+#define ICR_MA (1 << 4) /* master abort */
+#define ICR_SCLE (1 << 5) /* master clock enable */
+#define ICR_IUE (1 << 6) /* unit enable */
+#define ICR_GCD (1 << 7) /* general call disable */
+#define ICR_ITEIE (1 << 8) /* enable tx interrupts */
+#define ICR_IRFIE (1 << 9) /* enable rx interrupts */
+#define ICR_BEIE (1 << 10) /* enable bus error ints */
+#define ICR_SSDIE (1 << 11) /* slave STOP detected int enable */
+#define ICR_ALDIE (1 << 12) /* enable arbitration interrupt */
+#define ICR_SADIE (1 << 13) /* slave address detected int enable */
+#define ICR_UR (1 << 14) /* unit reset */
+#define ICR_FM (1 << 15) /* fast mode */
+#define ICR_HS (1 << 16) /* High Speed mode */
+#define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */
+
+#define ISR_RWM (1 << 0) /* read/write mode */
+#define ISR_ACKNAK (1 << 1) /* ack/nak status */
+#define ISR_UB (1 << 2) /* unit busy */
+#define ISR_IBB (1 << 3) /* bus busy */
+#define ISR_SSD (1 << 4) /* slave stop detected */
+#define ISR_ALD (1 << 5) /* arbitration loss detected */
+#define ISR_ITE (1 << 6) /* tx buffer empty */
+#define ISR_IRF (1 << 7) /* rx buffer full */
+#define ISR_GCAD (1 << 8) /* general call address detected */
+#define ISR_SAD (1 << 9) /* slave address detected */
+#define ISR_BED (1 << 10) /* bus error no ACK/NAK */
+
+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;
+ struct clk *clk;
+#ifdef CONFIG_I2C_PXA_SLAVE
+ struct i2c_slave_client *slave;
+#endif
+
+ unsigned int irqlogidx;
+ u32 isrlog[32];
+ u32 icrlog[32];
+
+ void __iomem *reg_base;
+ void __iomem *reg_ibmr;
+ void __iomem *reg_idbr;
+ void __iomem *reg_icr;
+ void __iomem *reg_isr;
+ void __iomem *reg_isar;
+
+ unsigned long iobase;
+ unsigned long iosize;
+
+ int irq;
+ unsigned int use_pio :1;
+ unsigned int fast_mode :1;
+ unsigned int high_mode:1;
+ unsigned char master_code;
+ unsigned long rate;
+ bool highmode_enter;
+};
+
+#define _IBMR(i2c) ((i2c)->reg_ibmr)
+#define _IDBR(i2c) ((i2c)->reg_idbr)
+#define _ICR(i2c) ((i2c)->reg_icr)
+#define _ISR(i2c) ((i2c)->reg_isr)
+#define _ISAR(i2c) ((i2c)->reg_isar)
+
+/*
+ * I2C Slave mode address
+ */
+#define I2C_PXA_SLAVE_ADDR 0x1
+
+#ifdef DEBUG
+
+struct bits {
+ u32 mask;
+ const char *set;
+ const char *unset;
+};
+#define PXA_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[] = {
+ PXA_BIT(ISR_RWM, "RX", "TX"),
+ PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
+ PXA_BIT(ISR_UB, "Bsy", "Rdy"),
+ PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
+ PXA_BIT(ISR_SSD, "SlaveStop", NULL),
+ PXA_BIT(ISR_ALD, "ALD", NULL),
+ PXA_BIT(ISR_ITE, "TxEmpty", NULL),
+ PXA_BIT(ISR_IRF, "RxFull", NULL),
+ PXA_BIT(ISR_GCAD, "GenCall", NULL),
+ PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
+ PXA_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[] = {
+ PXA_BIT(ICR_START, "START", NULL),
+ PXA_BIT(ICR_STOP, "STOP", NULL),
+ PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
+ PXA_BIT(ICR_TB, "TB", NULL),
+ PXA_BIT(ICR_MA, "MA", NULL),
+ PXA_BIT(ICR_SCLE, "SCLE", "scle"),
+ PXA_BIT(ICR_IUE, "IUE", "iue"),
+ PXA_BIT(ICR_GCD, "GCD", NULL),
+ PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
+ PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
+ PXA_BIT(ICR_BEIE, "BEIE", NULL),
+ PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
+ PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
+ PXA_BIT(ICR_SADIE, "SADIE", NULL),
+ PXA_BIT(ICR_UR, "UR", "ur"),
+};
+
+#ifdef CONFIG_I2C_PXA_SLAVE
+static void decode_ICR(unsigned int val)
+{
+ decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
+ printk("\n");
+}
+#endif
+
+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,
+ readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
+}
+
+#define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
+
+static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
+{
+ unsigned int i;
+ printk(KERN_ERR "i2c: error: %s\n", why);
+ printk(KERN_ERR "i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
+ i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
+ printk(KERN_ERR "i2c: ICR: %08x ISR: %08x\n",
+ readl(_ICR(i2c)), readl(_ISR(i2c)));
+ printk(KERN_DEBUG "i2c: log: ");
+ for (i = 0; i < i2c->irqlogidx; i++)
+ printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
+ printk("\n");
+}
+
+#else /* ifdef DEBUG */
+
+#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)
+#define i2c_pxa_scream_blue_murder(i2c, why) do { } while (0)
+
+#endif /* ifdef DEBUG / else */
+
+static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
+static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
+
+static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
+{
+ return !(readl(_ICR(i2c)) & ICR_SCLE);
+}
+
+static void i2c_pxa_abort(struct pxa_i2c *i2c)
+{
+ int i = 250;
+
+ if (i2c_pxa_is_slavemode(i2c)) {
+ dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
+ return;
+ }
+
+ while ((i > 0) && (readl(_IBMR(i2c)) & 0x1) == 0) {
+ unsigned long icr = readl(_ICR(i2c));
+
+ icr &= ~ICR_START;
+ icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
+
+ writel(icr, _ICR(i2c));
+
+ show_state(i2c);
+
+ mdelay(1);
+ i --;
+ }
+
+ writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
+ _ICR(i2c));
+}
+
+static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
+{
+ int timeout = DEF_TIMEOUT;
+
+ while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
+ if ((readl(_ISR(i2c)) & 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, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
+
+ if (readl(_ISR(i2c)) & 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 ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 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 ((readl(_ISR(i2c)) & (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;
+ }
+ }
+
+ writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
+ 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, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
+
+ if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
+ (readl(_ISR(i2c)) & ISR_SAD) != 0 ||
+ (readl(_ICR(i2c)) & 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 (readl(_ICR(i2c)) & ICR_STOP) {
+ udelay(100);
+ writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
+ }
+
+ if (!i2c_pxa_wait_slave(i2c)) {
+ dev_err(&i2c->adap.dev, "%s: wait timedout\n",
+ __func__);
+ return;
+ }
+ }
+
+ writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
+ writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
+
+ if (i2c_debug) {
+ dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
+ decode_ICR(readl(_ICR(i2c)));
+ }
+}
+#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 */
+ writel(ICR_UR, _ICR(i2c));
+ writel(I2C_ISR_INIT, _ISR(i2c));
+ writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
+
+ if (i2c->reg_isar)
+ writel(i2c->slave_addr, _ISAR(i2c));
+
+ /* set control register values */
+ writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
+ writel(readl(_ICR(i2c)) | (i2c->high_mode ? ICR_HS : 0), _ICR(i2c));
+
+#ifdef CONFIG_I2C_PXA_SLAVE
+ dev_info(&i2c->adap.dev, "Enabling slave mode\n");
+ writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
+#endif
+
+ i2c_pxa_set_slave(i2c, 0);
+
+ /* enable unit */
+ writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
+ udelay(100);
+}
+
+
+#ifdef CONFIG_I2C_PXA_SLAVE
+/*
+ * 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 = 0;
+
+ if (i2c->slave != NULL)
+ ret = i2c->slave->read(i2c->slave->data);
+
+ writel(ret, _IDBR(i2c));
+ writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
+ }
+}
+
+static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
+{
+ unsigned int byte = readl(_IDBR(i2c));
+
+ if (i2c->slave != NULL)
+ i2c->slave->write(i2c->slave->data, byte);
+
+ writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
+}
+
+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
+ */
+ writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
+ writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
+
+ timeout = 0x10000;
+
+ while (1) {
+ if ((readl(_IBMR(i2c)) & 2) == 2)
+ break;
+
+ timeout--;
+
+ if (timeout <= 0) {
+ dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
+ break;
+ }
+ }
+
+ writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
+}
+
+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 {
+ writel(0, _IDBR(i2c));
+ writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
+ }
+}
+
+static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
+{
+ writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
+}
+
+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
+ */
+ writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
+ writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
+
+ timeout = 0x10000;
+
+ while (1) {
+ if ((readl(_IBMR(i2c)) & 2) == 2)
+ break;
+
+ timeout--;
+
+ if (timeout <= 0) {
+ dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
+ break;
+ }
+ }
+
+ writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
+}
+
+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
+ */
+ writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
+
+ /*
+ * Step 2: initiate the write.
+ */
+ icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
+ writel(icr | ICR_START | ICR_TB, _ICR(i2c));
+}
+
+static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
+{
+ u32 icr;
+
+ /*
+ * Clear the STOP and ACK flags
+ */
+ icr = readl(_ICR(i2c));
+ icr &= ~(ICR_STOP | ICR_ACKNAK);
+ writel(icr, _ICR(i2c));
+}
+
+static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
+{
+ /* make timeout the same as for interrupt based functions */
+ long timeout = 2 * DEF_TIMEOUT;
+
+ /*
+ * Wait for the bus to become free.
+ */
+ while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
+ udelay(1000);
+ show_state(i2c);
+ }
+
+ if (timeout < 0) {
+ show_state(i2c);
+ dev_err(&i2c->adap.dev,
+ "i2c_pxa: timeout waiting for bus free\n");
+ return I2C_RETRY;
+ }
+
+ /*
+ * Set master mode.
+ */
+ writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
+
+ return 0;
+}
+
+/*
+ * PXA I2C send master code
+ * 1. Load master code to IDBR and send it.
+ * Note for HS mode, set ICR [GPIOEN].
+ * 2. Wait until win arbitration.
+ */
+static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
+{
+ u32 icr;
+ long timeout;
+
+ spin_lock_irq(&i2c->lock);
+ i2c->highmode_enter = true;
+ writel(i2c->master_code, _IDBR(i2c));
+
+ icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
+ icr |= ICR_GPIOEN | ICR_START | ICR_TB | ICR_ITEIE;
+ writel(icr, _ICR(i2c));
+
+ spin_unlock_irq(&i2c->lock);
+ timeout = wait_event_timeout(i2c->wait,
+ i2c->highmode_enter == false, HZ * 1);
+
+ i2c->highmode_enter = false;
+
+ return (timeout == 0) ? I2C_RETRY : 0;
+}
+
+static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
+ struct i2c_msg *msg, int num)
+{
+ unsigned long timeout = 500000; /* 5 seconds */
+ int ret = 0;
+
+ ret = i2c_pxa_pio_set_master(i2c);
+ if (ret)
+ goto out;
+
+ i2c->msg = msg;
+ i2c->msg_num = num;
+ i2c->msg_idx = 0;
+ i2c->msg_ptr = 0;
+ i2c->irqlogidx = 0;
+
+ i2c_pxa_start_message(i2c);
+
+ while (i2c->msg_num > 0 && --timeout) {
+ i2c_pxa_handler(0, i2c);
+ udelay(10);
+ }
+
+ i2c_pxa_stop_message(i2c);
+
+ /*
+ * We place the return code in i2c->msg_idx.
+ */
+ ret = i2c->msg_idx;
+
+out:
+ if (timeout == 0)
+ i2c_pxa_scream_blue_murder(i2c, "timeout");
+
+ return ret;
+}
+
+/*
+ * 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;
+ }
+
+ if (i2c->high_mode) {
+ ret = i2c_pxa_send_mastercode(i2c);
+ if (ret) {
+ dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");
+ 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);
+ i2c_pxa_stop_message(i2c);
+
+ /*
+ * We place the return code in i2c->msg_idx.
+ */
+ ret = i2c->msg_idx;
+
+ if (!timeout && i2c->msg_num) {
+ i2c_pxa_scream_blue_murder(i2c, "timeout");
+ ret = I2C_RETRY;
+ }
+
+ out:
+ return ret;
+}
+
+static int i2c_pxa_pio_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 (!(readl(_ICR(i2c)) & ICR_IUE))
+ i2c_pxa_reset(i2c);
+
+ for (i = adap->retries; i >= 0; i--) {
+ ret = i2c_pxa_do_pio_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;
+}
+
+/*
+ * 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;
+ if (!i2c->use_pio)
+ wake_up(&i2c->wait);
+}
+
+static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
+{
+ u32 icr = readl(_ICR(i2c)) & ~(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) &&
+ (!((i2c->msg->flags & I2C_M_IGNORE_NAK) &&
+ (isr & ISR_ACKNAK)))) {
+ 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.
+ */
+ writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
+
+ icr |= ICR_ALDIE | ICR_TB;
+
+ /*
+ * If this is the last byte of the last message or last byte
+ * of any message with I2C_M_STOP (e.g. SCCB), send a STOP.
+ */
+ if ((i2c->msg_ptr == i2c->msg->len) &&
+ ((i2c->msg->flags & I2C_M_STOP) ||
+ (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.
+ */
+ writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
+
+ /*
+ * 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;
+
+ writel(icr, _ICR(i2c));
+ show_state(i2c);
+}
+
+static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
+{
+ u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
+
+ /*
+ * Read the byte.
+ */
+ i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
+
+ 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;
+
+ writel(icr, _ICR(i2c));
+}
+
+#define VALID_INT_SOURCE (ISR_SSD | ISR_ALD | ISR_ITE | ISR_IRF | \
+ ISR_SAD | ISR_BED)
+static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
+{
+ struct pxa_i2c *i2c = dev_id;
+ u32 isr = readl(_ISR(i2c));
+
+ if (!(isr & VALID_INT_SOURCE))
+ return IRQ_NONE;
+
+ if (i2c_debug > 2 && 0) {
+ dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
+ __func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
+ decode_ISR(isr);
+ }
+
+ if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
+ i2c->isrlog[i2c->irqlogidx++] = isr;
+
+ show_state(i2c);
+
+ /*
+ * Always clear all pending IRQs.
+ */
+ writel(isr & VALID_INT_SOURCE, _ISR(i2c));
+
+ 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 && (!i2c->highmode_enter)) {
+ if (isr & ISR_ITE)
+ i2c_pxa_irq_txempty(i2c, isr);
+ if (isr & ISR_IRF)
+ i2c_pxa_irq_rxfull(i2c, isr);
+ } else if ((isr & ISR_ITE) && i2c->highmode_enter) {
+ i2c->highmode_enter = false;
+ wake_up(&i2c->wait);
+ } 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 u32 i2c_pxa_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
+}
+
+static const struct i2c_algorithm i2c_pxa_algorithm = {
+ .master_xfer = i2c_pxa_xfer,
+ .functionality = i2c_pxa_functionality,
+};
+
+static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
+ .master_xfer = i2c_pxa_pio_xfer,
+ .functionality = i2c_pxa_functionality,
+};
+
+static const struct of_device_id i2c_pxa_dt_ids[] = {
+ { .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
+ { .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
+ { .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA2XX },
+ {}
+};
+MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
+
+static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
+ enum pxa_i2c_types *i2c_types)
+{
+ struct device_node *np = pdev->dev.of_node;
+ const struct of_device_id *of_id =
+ of_match_device(i2c_pxa_dt_ids, &pdev->dev);
+
+ if (!of_id)
+ return 1;
+
+ /* For device tree we always use the dynamic or alias-assigned ID */
+ i2c->adap.nr = -1;
+
+ if (of_get_property(np, "mrvl,i2c-polling", NULL))
+ i2c->use_pio = 1;
+ if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
+ i2c->fast_mode = 1;
+ *i2c_types = (u32)(of_id->data);
+ return 0;
+}
+
+static int i2c_pxa_probe_pdata(struct platform_device *pdev,
+ struct pxa_i2c *i2c,
+ enum pxa_i2c_types *i2c_types)
+{
+ struct i2c_pxa_platform_data *plat = dev_get_platdata(&pdev->dev);
+ const struct platform_device_id *id = platform_get_device_id(pdev);
+
+ *i2c_types = id->driver_data;
+ if (plat) {
+ i2c->use_pio = plat->use_pio;
+ i2c->fast_mode = plat->fast_mode;
+ i2c->high_mode = plat->high_mode;
+ i2c->master_code = plat->master_code;
+ if (!i2c->master_code)
+ i2c->master_code = 0xe;
+ i2c->rate = plat->rate;
+ }
+ return 0;
+}
+
+static int i2c_pxa_probe(struct platform_device *dev)
+{
+ struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
+ enum pxa_i2c_types i2c_type;
+ struct pxa_i2c *i2c;
+ struct resource *res = NULL;
+ int ret, irq;
+
+ i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
+ if (!i2c) {
+ ret = -ENOMEM;
+ goto emalloc;
+ }
+
+ /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
+ i2c->adap.nr = dev->id;
+
+ ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
+ if (ret > 0)
+ ret = i2c_pxa_probe_pdata(dev, i2c, &i2c_type);
+ if (ret < 0)
+ goto eclk;
+
+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ irq = platform_get_irq(dev, 0);
+ if (res == NULL || irq < 0) {
+ ret = -ENODEV;
+ goto eclk;
+ }
+
+ if (!request_mem_region(res->start, resource_size(res), res->name)) {
+ ret = -ENOMEM;
+ goto eclk;
+ }
+
+ i2c->adap.owner = THIS_MODULE;
+ i2c->adap.retries = 5;
+
+ spin_lock_init(&i2c->lock);
+ init_waitqueue_head(&i2c->wait);
+
+ strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
+
+ i2c->clk = clk_get(&dev->dev, NULL);
+ if (IS_ERR(i2c->clk)) {
+ ret = PTR_ERR(i2c->clk);
+ goto eclk;
+ }
+
+ i2c->reg_base = ioremap(res->start, resource_size(res));
+ if (!i2c->reg_base) {
+ ret = -EIO;
+ goto eremap;
+ }
+
+ i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
+ i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
+ i2c->reg_icr = i2c->reg_base + pxa_reg_layout[i2c_type].icr;
+ i2c->reg_isr = i2c->reg_base + pxa_reg_layout[i2c_type].isr;
+ if (i2c_type != REGS_CE4100)
+ i2c->reg_isar = i2c->reg_base + pxa_reg_layout[i2c_type].isar;
+
+ i2c->iobase = res->start;
+ i2c->iosize = resource_size(res);
+
+ i2c->irq = irq;
+
+ i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
+ i2c->highmode_enter = false;
+
+ if (plat) {
+#ifdef CONFIG_I2C_PXA_SLAVE
+ i2c->slave_addr = plat->slave_addr;
+ i2c->slave = plat->slave;
+#endif
+ i2c->adap.class = plat->class;
+ }
+
+ if (i2c->high_mode) {
+ if (i2c->rate) {
+ clk_set_rate(i2c->clk, i2c->rate);
+ pr_info("i2c: <%s> set rate to %ld\n",
+ i2c->adap.name, clk_get_rate(i2c->clk));
+ } else
+ pr_warn("i2c: <%s> clock rate not set\n",
+ i2c->adap.name);
+ }
+
+ clk_prepare_enable(i2c->clk);
+
+ if (i2c->use_pio) {
+ i2c->adap.algo = &i2c_pxa_pio_algorithm;
+ } else {
+ i2c->adap.algo = &i2c_pxa_algorithm;
+ ret = request_irq(irq, i2c_pxa_handler, IRQF_SHARED,
+ dev_name(&dev->dev), i2c);
+ if (ret)
+ goto ereqirq;
+ }
+
+ i2c_pxa_reset(i2c);
+
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = &dev->dev;
+#ifdef CONFIG_OF
+ i2c->adap.dev.of_node = dev->dev.of_node;
+#endif
+
+ ret = i2c_add_numbered_adapter(&i2c->adap);
+ if (ret < 0) {
+ printk(KERN_INFO "I2C: Failed to add bus\n");
+ goto eadapt;
+ }
+
+ platform_set_drvdata(dev, i2c);
+
+#ifdef CONFIG_I2C_PXA_SLAVE
+ printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
+ dev_name(&i2c->adap.dev), i2c->slave_addr);
+#else
+ printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
+ dev_name(&i2c->adap.dev));
+#endif
+ return 0;
+
+eadapt:
+ if (!i2c->use_pio)
+ free_irq(irq, i2c);
+ereqirq:
+ clk_disable_unprepare(i2c->clk);
+ iounmap(i2c->reg_base);
+eremap:
+ clk_put(i2c->clk);
+eclk:
+ kfree(i2c);
+emalloc:
+ release_mem_region(res->start, resource_size(res));
+ return ret;
+}
+
+static int i2c_pxa_remove(struct platform_device *dev)
+{
+ struct pxa_i2c *i2c = platform_get_drvdata(dev);
+
+ i2c_del_adapter(&i2c->adap);
+ if (!i2c->use_pio)
+ free_irq(i2c->irq, i2c);
+
+ clk_disable_unprepare(i2c->clk);
+ clk_put(i2c->clk);
+
+ iounmap(i2c->reg_base);
+ release_mem_region(i2c->iobase, i2c->iosize);
+ kfree(i2c);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int i2c_pxa_suspend_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct pxa_i2c *i2c = platform_get_drvdata(pdev);
+
+ clk_disable(i2c->clk);
+
+ return 0;
+}
+
+static int i2c_pxa_resume_noirq(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct pxa_i2c *i2c = platform_get_drvdata(pdev);
+
+ clk_enable(i2c->clk);
+ i2c_pxa_reset(i2c);
+
+ return 0;
+}
+
+static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
+ .suspend_noirq = i2c_pxa_suspend_noirq,
+ .resume_noirq = i2c_pxa_resume_noirq,
+};
+
+#define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
+#else
+#define I2C_PXA_DEV_PM_OPS NULL
+#endif
+
+static struct platform_driver i2c_pxa_driver = {
+ .probe = i2c_pxa_probe,
+ .remove = i2c_pxa_remove,
+ .driver = {
+ .name = "pxa2xx-i2c",
+ .pm = I2C_PXA_DEV_PM_OPS,
+ .of_match_table = i2c_pxa_dt_ids,
+ },
+ .id_table = i2c_pxa_id_table,
+};
+
+static int __init i2c_adap_pxa_init(void)
+{
+ return platform_driver_register(&i2c_pxa_driver);
+}
+
+static void __exit i2c_adap_pxa_exit(void)
+{
+ platform_driver_unregister(&i2c_pxa_driver);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pxa2xx-i2c");
+
+subsys_initcall(i2c_adap_pxa_init);
+module_exit(i2c_adap_pxa_exit);
Code Review / kvmfornfv.git / blobdiff