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diff --git a/arch/ppc/platforms/pmac_low_i2c.c b/arch/ppc/platforms/pmac_low_i2c.c
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+/*
+ * arch/ppc/platforms/pmac_low_i2c.c
+ *
+ * Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * This file contains some low-level i2c access routines that
+ * need to be used by various bits of the PowerMac platform code
+ * at times where the real asynchronous & interrupt driven driver
+ * cannot be used. The API borrows some semantics from the darwin
+ * driver in order to ease the implementation of the platform
+ * properties parser
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <asm/keylargo.h>
+#include <asm/uninorth.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/pmac_low_i2c.h>
+
+#define MAX_LOW_I2C_HOST 4
+
+#if 1
+#define DBG(x...) do {\
+ printk(KERN_DEBUG "KW:" x); \
+ } while(0)
+#else
+#define DBGG(x...)
+#endif
+
+struct low_i2c_host;
+
+typedef int (*low_i2c_func_t)(struct low_i2c_host *host, u8 addr, u8 sub, u8 *data, int len);
+
+struct low_i2c_host
+{
+ struct device_node *np; /* OF device node */
+ struct semaphore mutex; /* Access mutex for use by i2c-keywest */
+ low_i2c_func_t func; /* Access function */
+ int is_open : 1; /* Poor man's access control */
+ int mode; /* Current mode */
+ int channel; /* Current channel */
+ int num_channels; /* Number of channels */
+ unsigned long base; /* For keywest-i2c, base address */
+ int bsteps; /* And register stepping */
+ int speed; /* And speed */
+};
+
+static struct low_i2c_host low_i2c_hosts[MAX_LOW_I2C_HOST];
+
+/* No locking is necessary on allocation, we are running way before
+ * anything can race with us
+ */
+static struct low_i2c_host *find_low_i2c_host(struct device_node *np)
+{
+ int i;
+
+ for (i = 0; i < MAX_LOW_I2C_HOST; i++)
+ if (low_i2c_hosts[i].np == np)
+ return &low_i2c_hosts[i];
+ return NULL;
+}
+
+/*
+ *
+ * i2c-keywest implementation (UniNorth, U2, U3, Keylargo's)
+ *
+ */
+
+/*
+ * Keywest i2c definitions borrowed from drivers/i2c/i2c-keywest.h,
+ * should be moved somewhere in include/asm-ppc/
+ */
+/* Register indices */
+typedef enum {
+ reg_mode = 0,
+ reg_control,
+ reg_status,
+ reg_isr,
+ reg_ier,
+ reg_addr,
+ reg_subaddr,
+ reg_data
+} reg_t;
+
+
+/* Mode register */
+#define KW_I2C_MODE_100KHZ 0x00
+#define KW_I2C_MODE_50KHZ 0x01
+#define KW_I2C_MODE_25KHZ 0x02
+#define KW_I2C_MODE_DUMB 0x00
+#define KW_I2C_MODE_STANDARD 0x04
+#define KW_I2C_MODE_STANDARDSUB 0x08
+#define KW_I2C_MODE_COMBINED 0x0C
+#define KW_I2C_MODE_MODE_MASK 0x0C
+#define KW_I2C_MODE_CHAN_MASK 0xF0
+
+/* Control register */
+#define KW_I2C_CTL_AAK 0x01
+#define KW_I2C_CTL_XADDR 0x02
+#define KW_I2C_CTL_STOP 0x04
+#define KW_I2C_CTL_START 0x08
+
+/* Status register */
+#define KW_I2C_STAT_BUSY 0x01
+#define KW_I2C_STAT_LAST_AAK 0x02
+#define KW_I2C_STAT_LAST_RW 0x04
+#define KW_I2C_STAT_SDA 0x08
+#define KW_I2C_STAT_SCL 0x10
+
+/* IER & ISR registers */
+#define KW_I2C_IRQ_DATA 0x01
+#define KW_I2C_IRQ_ADDR 0x02
+#define KW_I2C_IRQ_STOP 0x04
+#define KW_I2C_IRQ_START 0x08
+#define KW_I2C_IRQ_MASK 0x0F
+
+/* State machine states */
+enum {
+ state_idle,
+ state_addr,
+ state_read,
+ state_write,
+ state_stop,
+ state_dead
+};
+
+#define WRONG_STATE(name) do {\
+ printk(KERN_DEBUG "KW: wrong state. Got %s, state: %s (isr: %02x)\n", \
+ name, __kw_state_names[state], isr); \
+ } while(0)
+
+static const char *__kw_state_names[] = {
+ "state_idle",
+ "state_addr",
+ "state_read",
+ "state_write",
+ "state_stop",
+ "state_dead"
+};
+
+static inline u8 __kw_read_reg(struct low_i2c_host *host, reg_t reg)
+{
+ return in_8(((volatile u8 *)host->base)
+ + (((unsigned)reg) << host->bsteps));
+}
+
+static inline void __kw_write_reg(struct low_i2c_host *host, reg_t reg, u8 val)
+{
+ out_8(((volatile u8 *)host->base)
+ + (((unsigned)reg) << host->bsteps), val);
+ (void)__kw_read_reg(host, reg_subaddr);
+}
+
+#define kw_write_reg(reg, val) __kw_write_reg(host, reg, val)
+#define kw_read_reg(reg) __kw_read_reg(host, reg)
+
+
+/* Don't schedule, the g5 fan controller is too
+ * timing sensitive
+ */
+static u8 kw_wait_interrupt(struct low_i2c_host* host)
+{
+ int i;
+ u8 isr;
+
+ for (i = 0; i < 200000; i++) {
+ isr = kw_read_reg(reg_isr) & KW_I2C_IRQ_MASK;
+ if (isr != 0)
+ return isr;
+ udelay(1);
+ }
+ return isr;
+}
+
+static int kw_handle_interrupt(struct low_i2c_host *host, int state, int rw, int *rc, u8 **data, int *len, u8 isr)
+{
+ u8 ack;
+
+ if (isr == 0) {
+ if (state != state_stop) {
+ DBG("KW: Timeout !\n");
+ *rc = -EIO;
+ goto stop;
+ }
+ if (state == state_stop) {
+ ack = kw_read_reg(reg_status);
+ if (!(ack & KW_I2C_STAT_BUSY)) {
+ state = state_idle;
+ kw_write_reg(reg_ier, 0x00);
+ }
+ }
+ return state;
+ }
+
+ if (isr & KW_I2C_IRQ_ADDR) {
+ ack = kw_read_reg(reg_status);
+ if (state != state_addr) {
+ kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
+ WRONG_STATE("KW_I2C_IRQ_ADDR");
+ *rc = -EIO;
+ goto stop;
+ }
+ if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
+ *rc = -ENODEV;
+ DBG("KW: NAK on address\n");
+ return state_stop;
+ } else {
+ if (rw) {
+ state = state_read;
+ if (*len > 1)
+ kw_write_reg(reg_control, KW_I2C_CTL_AAK);
+ } else {
+ state = state_write;
+ kw_write_reg(reg_data, **data);
+ (*data)++; (*len)--;
+ }
+ }
+ kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
+ }
+
+ if (isr & KW_I2C_IRQ_DATA) {
+ if (state == state_read) {
+ **data = kw_read_reg(reg_data);
+ (*data)++; (*len)--;
+ kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
+ if ((*len) == 0)
+ state = state_stop;
+ else if ((*len) == 1)
+ kw_write_reg(reg_control, 0);
+ } else if (state == state_write) {
+ ack = kw_read_reg(reg_status);
+ if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
+ DBG("KW: nack on data write\n");
+ *rc = -EIO;
+ goto stop;
+ } else if (*len) {
+ kw_write_reg(reg_data, **data);
+ (*data)++; (*len)--;
+ } else {
+ kw_write_reg(reg_control, KW_I2C_CTL_STOP);
+ state = state_stop;
+ *rc = 0;
+ }
+ kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
+ } else {
+ kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
+ WRONG_STATE("KW_I2C_IRQ_DATA");
+ if (state != state_stop) {
+ *rc = -EIO;
+ goto stop;
+ }
+ }
+ }
+
+ if (isr & KW_I2C_IRQ_STOP) {
+ kw_write_reg(reg_isr, KW_I2C_IRQ_STOP);
+ if (state != state_stop) {
+ WRONG_STATE("KW_I2C_IRQ_STOP");
+ *rc = -EIO;
+ }
+ return state_idle;
+ }
+
+ if (isr & KW_I2C_IRQ_START)
+ kw_write_reg(reg_isr, KW_I2C_IRQ_START);
+
+ return state;
+
+ stop:
+ kw_write_reg(reg_control, KW_I2C_CTL_STOP);
+ return state_stop;
+}
+
+static int keywest_low_i2c_func(struct low_i2c_host *host, u8 addr, u8 subaddr, u8 *data, int len)
+{
+ u8 mode_reg = host->speed;
+ int state = state_addr;
+ int rc = 0;
+
+ /* Setup mode & subaddress if any */
+ switch(host->mode) {
+ case pmac_low_i2c_mode_dumb:
+ printk(KERN_ERR "low_i2c: Dumb mode not supported !\n");
+ return -EINVAL;
+ case pmac_low_i2c_mode_std:
+ mode_reg |= KW_I2C_MODE_STANDARD;
+ break;
+ case pmac_low_i2c_mode_stdsub:
+ mode_reg |= KW_I2C_MODE_STANDARDSUB;
+ kw_write_reg(reg_subaddr, subaddr);
+ break;
+ case pmac_low_i2c_mode_combined:
+ mode_reg |= KW_I2C_MODE_COMBINED;
+ kw_write_reg(reg_subaddr, subaddr);
+ break;
+ }
+
+ /* Setup channel & clear pending irqs */
+ kw_write_reg(reg_isr, kw_read_reg(reg_isr));
+ kw_write_reg(reg_mode, mode_reg | (host->channel << 4));
+ kw_write_reg(reg_status, 0);
+
+ /* Set up address and r/w bit */
+ kw_write_reg(reg_addr, addr);
+
+ /* Start sending address & disable interrupt*/
+ kw_write_reg(reg_ier, 0 /*KW_I2C_IRQ_MASK*/);
+ kw_write_reg(reg_control, KW_I2C_CTL_XADDR);
+
+ /* State machine, to turn into an interrupt handler */
+ while(state != state_idle) {
+ u8 isr = kw_wait_interrupt(host);
+ state = kw_handle_interrupt(host, state, addr & 1, &rc, &data, &len, isr);
+ }
+
+ return rc;
+}
+
+static void keywest_low_i2c_add(struct device_node *np)
+{
+ struct low_i2c_host *host = find_low_i2c_host(NULL);
+ unsigned long *psteps, *prate, steps, aoffset = 0;
+ struct device_node *parent;
+
+ if (host == NULL) {
+ printk(KERN_ERR "low_i2c: Can't allocate host for %s\n",
+ np->full_name);
+ return;
+ }
+ memset(host, 0, sizeof(*host));
+
+ init_MUTEX(&host->mutex);
+ host->np = of_node_get(np);
+ psteps = (unsigned long *)get_property(np, "AAPL,address-step", NULL);
+ steps = psteps ? (*psteps) : 0x10;
+ for (host->bsteps = 0; (steps & 0x01) == 0; host->bsteps++)
+ steps >>= 1;
+ parent = of_get_parent(np);
+ host->num_channels = 1;
+ if (parent && parent->name[0] == 'u') {
+ host->num_channels = 2;
+ aoffset = 3;
+ }
+ /* Select interface rate */
+ host->speed = KW_I2C_MODE_100KHZ;
+ prate = (unsigned long *)get_property(np, "AAPL,i2c-rate", NULL);
+ if (prate) switch(*prate) {
+ case 100:
+ host->speed = KW_I2C_MODE_100KHZ;
+ break;
+ case 50:
+ host->speed = KW_I2C_MODE_50KHZ;
+ break;
+ case 25:
+ host->speed = KW_I2C_MODE_25KHZ;
+ break;
+ }
+ host->mode = pmac_low_i2c_mode_std;
+ host->base = (unsigned long)ioremap(np->addrs[0].address + aoffset,
+ np->addrs[0].size);
+ host->func = keywest_low_i2c_func;
+}
+
+/*
+ *
+ * PMU implementation
+ *
+ */
+
+
+#ifdef CONFIG_ADB_PMU
+
+static int pmu_low_i2c_func(struct low_i2c_host *host, u8 addr, u8 sub, u8 *data, int len)
+{
+ // TODO
+ return -ENODEV;
+}
+
+static void pmu_low_i2c_add(struct device_node *np)
+{
+ struct low_i2c_host *host = find_low_i2c_host(NULL);
+
+ if (host == NULL) {
+ printk(KERN_ERR "low_i2c: Can't allocate host for %s\n",
+ np->full_name);
+ return;
+ }
+ memset(host, 0, sizeof(*host));
+
+ init_MUTEX(&host->mutex);
+ host->np = of_node_get(np);
+ host->num_channels = 3;
+ host->mode = pmac_low_i2c_mode_std;
+ host->func = pmu_low_i2c_func;
+}
+
+#endif /* CONFIG_ADB_PMU */
+
+void __init pmac_init_low_i2c(void)
+{
+ struct device_node *np;
+
+ /* Probe keywest-i2c busses */
+ np = of_find_compatible_node(NULL, "i2c", "keywest-i2c");
+ while(np) {
+ keywest_low_i2c_add(np);
+ np = of_find_compatible_node(np, "i2c", "keywest-i2c");
+ }
+
+#ifdef CONFIG_ADB_PMU
+ /* Probe PMU busses */
+ np = of_find_node_by_name(NULL, "via-pmu");
+ if (np)
+ pmu_low_i2c_add(np);
+#endif /* CONFIG_ADB_PMU */
+
+ /* TODO: Add CUDA support as well */
+}
+
+int pmac_low_i2c_lock(struct device_node *np)
+{
+ struct low_i2c_host *host = find_low_i2c_host(np);
+
+ if (!host)
+ return -ENODEV;
+ down(&host->mutex);
+ return 0;
+}
+EXPORT_SYMBOL(pmac_low_i2c_lock);
+
+int pmac_low_i2c_unlock(struct device_node *np)
+{
+ struct low_i2c_host *host = find_low_i2c_host(np);
+
+ if (!host)
+ return -ENODEV;
+ up(&host->mutex);
+ return 0;
+}
+EXPORT_SYMBOL(pmac_low_i2c_unlock);
+
+
+int pmac_low_i2c_open(struct device_node *np, int channel)
+{
+ struct low_i2c_host *host = find_low_i2c_host(np);
+
+ if (!host)
+ return -ENODEV;
+
+ if (channel >= host->num_channels)
+ return -EINVAL;
+
+ down(&host->mutex);
+ host->is_open = 1;
+ host->channel = channel;
+
+ return 0;
+}
+EXPORT_SYMBOL(pmac_low_i2c_open);
+
+int pmac_low_i2c_close(struct device_node *np)
+{
+ struct low_i2c_host *host = find_low_i2c_host(np);
+
+ if (!host)
+ return -ENODEV;
+
+ host->is_open = 0;
+ up(&host->mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL(pmac_low_i2c_close);
+
+int pmac_low_i2c_setmode(struct device_node *np, int mode)
+{
+ struct low_i2c_host *host = find_low_i2c_host(np);
+
+ if (!host)
+ return -ENODEV;
+ WARN_ON(!host->is_open);
+ host->mode = mode;
+
+ return 0;
+}
+EXPORT_SYMBOL(pmac_low_i2c_setmode);
+
+int pmac_low_i2c_xfer(struct device_node *np, u8 addrdir, u8 subaddr, u8 *data, int len)
+{
+ struct low_i2c_host *host = find_low_i2c_host(np);
+
+ if (!host)
+ return -ENODEV;
+ WARN_ON(!host->is_open);
+
+ return host->func(host, addrdir, subaddr, data, len);
+}
+EXPORT_SYMBOL(pmac_low_i2c_xfer);
+