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linux/arch/powerpc/platforms/powermac/low_i2c.c
Johannes Berg 76a5b8bb35 [POWERPC] powermac i2c: Use mutex 
Convert the semaphores in low_i2c that are used as mutexes to real
mutexes.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-07-10 21:55:54 +10:00

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/*
* arch/powerpc/platforms/powermac/low_i2c.c
*
* Copyright (C) 2003-2005 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.
*
* The linux i2c layer isn't completely suitable for our needs for various
* reasons ranging from too late initialisation to semantics not perfectly
* matching some requirements of the apple platform functions etc...
*
* This file thus provides a simple low level unified i2c interface for
* powermac that covers the various types of i2c busses used in Apple machines.
* For now, keywest, PMU and SMU, though we could add Cuda, or other bit
* banging busses found on older chipstes in earlier machines if we ever need
* one of them.
*
* The drivers in this file are synchronous/blocking. In addition, the
* keywest one is fairly slow due to the use of msleep instead of interrupts
* as the interrupt is currently used by i2c-keywest. In the long run, we
* might want to get rid of those high-level interfaces to linux i2c layer
* either completely (converting all drivers) or replacing them all with a
* single stub driver on top of this one. Once done, the interrupt will be
* available for our use.
*/
#undef DEBUG
#undef DEBUG_LOW
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/timer.h>
#include <linux/mutex.h>
#include <asm/keylargo.h>
#include <asm/uninorth.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/smu.h>
#include <asm/pmac_pfunc.h>
#include <asm/pmac_low_i2c.h>
#ifdef DEBUG
#define DBG(x...) do {\
printk(KERN_DEBUG "low_i2c:" x); \
} while(0)
#else
#define DBG(x...)
#endif
#ifdef DEBUG_LOW
#define DBG_LOW(x...) do {\
printk(KERN_DEBUG "low_i2c:" x); \
} while(0)
#else
#define DBG_LOW(x...)
#endif
static int pmac_i2c_force_poll = 1;
/*
* A bus structure. Each bus in the system has such a structure associated.
*/
struct pmac_i2c_bus
{
struct list_head link;
struct device_node *controller;
struct device_node *busnode;
int type;
int flags;
struct i2c_adapter *adapter;
void *hostdata;
int channel; /* some hosts have multiple */
int mode; /* current mode */
struct mutex mutex;
int opened;
int polled; /* open mode */
struct platform_device *platform_dev;
/* ops */
int (*open)(struct pmac_i2c_bus *bus);
void (*close)(struct pmac_i2c_bus *bus);
int (*xfer)(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
u32 subaddr, u8 *data, int len);
};
static LIST_HEAD(pmac_i2c_busses);
/*
* Keywest implementation
*/
struct pmac_i2c_host_kw
{
struct mutex mutex; /* Access mutex for use by
* i2c-keywest */
void __iomem *base; /* register base address */
int bsteps; /* register stepping */
int speed; /* speed */
int irq;
u8 *data;
unsigned len;
int state;
int rw;
int polled;
int result;
struct completion complete;
spinlock_t lock;
struct timer_list timeout_timer;
};
/* Register indices */
typedef enum {
reg_mode = 0,
reg_control,
reg_status,
reg_isr,
reg_ier,
reg_addr,
reg_subaddr,
reg_data
} reg_t;
/* The Tumbler audio equalizer can be really slow sometimes */
#define KW_POLL_TIMEOUT (2*HZ)
/* 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[host->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 pmac_i2c_host_kw *host, reg_t reg)
{
return readb(host->base + (((unsigned int)reg) << host->bsteps));
}
static inline void __kw_write_reg(struct pmac_i2c_host_kw *host,
reg_t reg, u8 val)
{
writeb(val, host->base + (((unsigned)reg) << host->bsteps));
(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)
static u8 kw_i2c_wait_interrupt(struct pmac_i2c_host_kw *host)
{
int i, j;
u8 isr;
for (i = 0; i < 1000; i++) {
isr = kw_read_reg(reg_isr) & KW_I2C_IRQ_MASK;
if (isr != 0)
return isr;
/* This code is used with the timebase frozen, we cannot rely
* on udelay nor schedule when in polled mode !
* For now, just use a bogus loop....
*/
if (host->polled) {
for (j = 1; j < 100000; j++)
mb();
} else
msleep(1);
}
return isr;
}
static void kw_i2c_do_stop(struct pmac_i2c_host_kw *host, int result)
{
kw_write_reg(reg_control, KW_I2C_CTL_STOP);
host->state = state_stop;
host->result = result;
}
static void kw_i2c_handle_interrupt(struct pmac_i2c_host_kw *host, u8 isr)
{
u8 ack;
DBG_LOW("kw_handle_interrupt(%s, isr: %x)\n",
__kw_state_names[host->state], isr);
if (host->state == state_idle) {
printk(KERN_WARNING "low_i2c: Keywest got an out of state"
" interrupt, ignoring\n");
kw_write_reg(reg_isr, isr);
return;
}
if (isr == 0) {
printk(KERN_WARNING "low_i2c: Timeout in i2c transfer"
" on keywest !\n");
if (host->state != state_stop) {
kw_i2c_do_stop(host, -EIO);
return;
}
ack = kw_read_reg(reg_status);
if (ack & KW_I2C_STAT_BUSY)
kw_write_reg(reg_status, 0);
host->state = state_idle;
kw_write_reg(reg_ier, 0x00);
if (!host->polled)
complete(&host->complete);
return;
}
if (isr & KW_I2C_IRQ_ADDR) {
ack = kw_read_reg(reg_status);
if (host->state != state_addr) {
WRONG_STATE("KW_I2C_IRQ_ADDR");
kw_i2c_do_stop(host, -EIO);
}
if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
host->result = -ENXIO;
host->state = state_stop;
DBG_LOW("KW: NAK on address\n");
} else {
if (host->len == 0)
kw_i2c_do_stop(host, 0);
else if (host->rw) {
host->state = state_read;
if (host->len > 1)
kw_write_reg(reg_control,
KW_I2C_CTL_AAK);
} else {
host->state = state_write;
kw_write_reg(reg_data, *(host->data++));
host->len--;
}
}
kw_write_reg(reg_isr, KW_I2C_IRQ_ADDR);
}
if (isr & KW_I2C_IRQ_DATA) {
if (host->state == state_read) {
*(host->data++) = kw_read_reg(reg_data);
host->len--;
kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
if (host->len == 0)
host->state = state_stop;
else if (host->len == 1)
kw_write_reg(reg_control, 0);
} else if (host->state == state_write) {
ack = kw_read_reg(reg_status);
if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
DBG_LOW("KW: nack on data write\n");
host->result = -EFBIG;
host->state = state_stop;
} else if (host->len) {
kw_write_reg(reg_data, *(host->data++));
host->len--;
} else
kw_i2c_do_stop(host, 0);
} else {
WRONG_STATE("KW_I2C_IRQ_DATA");
if (host->state != state_stop)
kw_i2c_do_stop(host, -EIO);
}
kw_write_reg(reg_isr, KW_I2C_IRQ_DATA);
}
if (isr & KW_I2C_IRQ_STOP) {
kw_write_reg(reg_isr, KW_I2C_IRQ_STOP);
if (host->state != state_stop) {
WRONG_STATE("KW_I2C_IRQ_STOP");
host->result = -EIO;
}
host->state = state_idle;
if (!host->polled)
complete(&host->complete);
}
/* Below should only happen in manual mode which we don't use ... */
if (isr & KW_I2C_IRQ_START)
kw_write_reg(reg_isr, KW_I2C_IRQ_START);
}
/* Interrupt handler */
static irqreturn_t kw_i2c_irq(int irq, void *dev_id)
{
struct pmac_i2c_host_kw *host = dev_id;
unsigned long flags;
spin_lock_irqsave(&host->lock, flags);
del_timer(&host->timeout_timer);
kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr));
if (host->state != state_idle) {
host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
add_timer(&host->timeout_timer);
}
spin_unlock_irqrestore(&host->lock, flags);
return IRQ_HANDLED;
}
static void kw_i2c_timeout(unsigned long data)
{
struct pmac_i2c_host_kw *host = (struct pmac_i2c_host_kw *)data;
unsigned long flags;
spin_lock_irqsave(&host->lock, flags);
kw_i2c_handle_interrupt(host, kw_read_reg(reg_isr));
if (host->state != state_idle) {
host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
add_timer(&host->timeout_timer);
}
spin_unlock_irqrestore(&host->lock, flags);
}
static int kw_i2c_open(struct pmac_i2c_bus *bus)
{
struct pmac_i2c_host_kw *host = bus->hostdata;
mutex_lock(&host->mutex);
return 0;
}
static void kw_i2c_close(struct pmac_i2c_bus *bus)
{
struct pmac_i2c_host_kw *host = bus->hostdata;
mutex_unlock(&host->mutex);
}
static int kw_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
u32 subaddr, u8 *data, int len)
{
struct pmac_i2c_host_kw *host = bus->hostdata;
u8 mode_reg = host->speed;
int use_irq = host->irq != NO_IRQ && !bus->polled;
/* Setup mode & subaddress if any */
switch(bus->mode) {
case pmac_i2c_mode_dumb:
return -EINVAL;
case pmac_i2c_mode_std:
mode_reg |= KW_I2C_MODE_STANDARD;
if (subsize != 0)
return -EINVAL;
break;
case pmac_i2c_mode_stdsub:
mode_reg |= KW_I2C_MODE_STANDARDSUB;
if (subsize != 1)
return -EINVAL;
break;
case pmac_i2c_mode_combined:
mode_reg |= KW_I2C_MODE_COMBINED;
if (subsize != 1)
return -EINVAL;
break;
}
/* Setup channel & clear pending irqs */
kw_write_reg(reg_isr, kw_read_reg(reg_isr));
kw_write_reg(reg_mode, mode_reg | (bus->channel << 4));
kw_write_reg(reg_status, 0);
/* Set up address and r/w bit, strip possible stale bus number from
* address top bits
*/
kw_write_reg(reg_addr, addrdir & 0xff);
/* Set up the sub address */
if ((mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_STANDARDSUB
|| (mode_reg & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_COMBINED)
kw_write_reg(reg_subaddr, subaddr);
/* Prepare for async operations */
host->data = data;
host->len = len;
host->state = state_addr;
host->result = 0;
host->rw = (addrdir & 1);
host->polled = bus->polled;
/* Enable interrupt if not using polled mode and interrupt is
* available
*/
if (use_irq) {
/* Clear completion */
INIT_COMPLETION(host->complete);
/* Ack stale interrupts */
kw_write_reg(reg_isr, kw_read_reg(reg_isr));
/* Arm timeout */
host->timeout_timer.expires = jiffies + KW_POLL_TIMEOUT;
add_timer(&host->timeout_timer);
/* Enable emission */
kw_write_reg(reg_ier, KW_I2C_IRQ_MASK);
}
/* Start sending address */
kw_write_reg(reg_control, KW_I2C_CTL_XADDR);
/* Wait for completion */
if (use_irq)
wait_for_completion(&host->complete);
else {
while(host->state != state_idle) {
unsigned long flags;
u8 isr = kw_i2c_wait_interrupt(host);
spin_lock_irqsave(&host->lock, flags);
kw_i2c_handle_interrupt(host, isr);
spin_unlock_irqrestore(&host->lock, flags);
}
}
/* Disable emission */
kw_write_reg(reg_ier, 0);
return host->result;
}
static struct pmac_i2c_host_kw *__init kw_i2c_host_init(struct device_node *np)
{
struct pmac_i2c_host_kw *host;
const u32 *psteps, *prate, *addrp;
u32 steps;
host = kzalloc(sizeof(struct pmac_i2c_host_kw), GFP_KERNEL);
if (host == NULL) {
printk(KERN_ERR "low_i2c: Can't allocate host for %s\n",
np->full_name);
return NULL;
}
/* Apple is kind enough to provide a valid AAPL,address property
* on all i2c keywest nodes so far ... we would have to fallback
* to macio parsing if that wasn't the case
*/
addrp = of_get_property(np, "AAPL,address", NULL);
if (addrp == NULL) {
printk(KERN_ERR "low_i2c: Can't find address for %s\n",
np->full_name);
kfree(host);
return NULL;
}
mutex_init(&host->mutex);
init_completion(&host->complete);
spin_lock_init(&host->lock);
init_timer(&host->timeout_timer);
host->timeout_timer.function = kw_i2c_timeout;
host->timeout_timer.data = (unsigned long)host;
psteps = of_get_property(np, "AAPL,address-step", NULL);
steps = psteps ? (*psteps) : 0x10;
for (host->bsteps = 0; (steps & 0x01) == 0; host->bsteps++)
steps >>= 1;
/* Select interface rate */
host->speed = KW_I2C_MODE_25KHZ;
prate = of_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->irq = irq_of_parse_and_map(np, 0);
if (host->irq == NO_IRQ)
printk(KERN_WARNING
"low_i2c: Failed to map interrupt for %s\n",
np->full_name);
host->base = ioremap((*addrp), 0x1000);
if (host->base == NULL) {
printk(KERN_ERR "low_i2c: Can't map registers for %s\n",
np->full_name);
kfree(host);
return NULL;
}
/* Make sure IRQ is disabled */
kw_write_reg(reg_ier, 0);
/* Request chip interrupt */
if (request_irq(host->irq, kw_i2c_irq, 0, "keywest i2c", host))
host->irq = NO_IRQ;
printk(KERN_INFO "KeyWest i2c @0x%08x irq %d %s\n",
*addrp, host->irq, np->full_name);
return host;
}
static void __init kw_i2c_add(struct pmac_i2c_host_kw *host,
struct device_node *controller,
struct device_node *busnode,
int channel)
{
struct pmac_i2c_bus *bus;
bus = kzalloc(sizeof(struct pmac_i2c_bus), GFP_KERNEL);
if (bus == NULL)
return;
bus->controller = of_node_get(controller);
bus->busnode = of_node_get(busnode);
bus->type = pmac_i2c_bus_keywest;
bus->hostdata = host;
bus->channel = channel;
bus->mode = pmac_i2c_mode_std;
bus->open = kw_i2c_open;
bus->close = kw_i2c_close;
bus->xfer = kw_i2c_xfer;
mutex_init(&bus->mutex);
if (controller == busnode)
bus->flags = pmac_i2c_multibus;
list_add(&bus->link, &pmac_i2c_busses);
printk(KERN_INFO " channel %d bus %s\n", channel,
(controller == busnode) ? "<multibus>" : busnode->full_name);
}
static void __init kw_i2c_probe(void)
{
struct device_node *np, *child, *parent;
/* Probe keywest-i2c busses */
for (np = NULL;
(np = of_find_compatible_node(np, "i2c","keywest-i2c")) != NULL;){
struct pmac_i2c_host_kw *host;
int multibus, chans, i;
/* Found one, init a host structure */
host = kw_i2c_host_init(np);
if (host == NULL)
continue;
/* Now check if we have a multibus setup (old style) or if we
* have proper bus nodes. Note that the "new" way (proper bus
* nodes) might cause us to not create some busses that are
* kept hidden in the device-tree. In the future, we might
* want to work around that by creating busses without a node
* but not for now
*/
child = of_get_next_child(np, NULL);
multibus = !child || strcmp(child->name, "i2c-bus");
of_node_put(child);
/* For a multibus setup, we get the bus count based on the
* parent type
*/
if (multibus) {
parent = of_get_parent(np);
if (parent == NULL)
continue;
chans = parent->name[0] == 'u' ? 2 : 1;
for (i = 0; i < chans; i++)
kw_i2c_add(host, np, np, i);
} else {
for (child = NULL;
(child = of_get_next_child(np, child)) != NULL;) {
const u32 *reg = of_get_property(child,
"reg", NULL);
if (reg == NULL)
continue;
kw_i2c_add(host, np, child, *reg);
}
}
}
}
/*
*
* PMU implementation
*
*/
#ifdef CONFIG_ADB_PMU
/*
* i2c command block to the PMU
*/
struct pmu_i2c_hdr {
u8 bus;
u8 mode;
u8 bus2;
u8 address;
u8 sub_addr;
u8 comb_addr;
u8 count;
u8 data[];
};
static void pmu_i2c_complete(struct adb_request *req)
{
complete(req->arg);
}
static int pmu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
u32 subaddr, u8 *data, int len)
{
struct adb_request *req = bus->hostdata;
struct pmu_i2c_hdr *hdr = (struct pmu_i2c_hdr *)&req->data[1];
struct completion comp;
int read = addrdir & 1;
int retry;
int rc = 0;
/* For now, limit ourselves to 16 bytes transfers */
if (len > 16)
return -EINVAL;
init_completion(&comp);
for (retry = 0; retry < 16; retry++) {
memset(req, 0, sizeof(struct adb_request));
hdr->bus = bus->channel;
hdr->count = len;
switch(bus->mode) {
case pmac_i2c_mode_std:
if (subsize != 0)
return -EINVAL;
hdr->address = addrdir;
hdr->mode = PMU_I2C_MODE_SIMPLE;
break;
case pmac_i2c_mode_stdsub:
case pmac_i2c_mode_combined:
if (subsize != 1)
return -EINVAL;
hdr->address = addrdir & 0xfe;
hdr->comb_addr = addrdir;
hdr->sub_addr = subaddr;
if (bus->mode == pmac_i2c_mode_stdsub)
hdr->mode = PMU_I2C_MODE_STDSUB;
else
hdr->mode = PMU_I2C_MODE_COMBINED;
break;
default:
return -EINVAL;
}
INIT_COMPLETION(comp);
req->data[0] = PMU_I2C_CMD;
req->reply[0] = 0xff;
req->nbytes = sizeof(struct pmu_i2c_hdr) + 1;
req->done = pmu_i2c_complete;
req->arg = &comp;
if (!read && len) {
memcpy(hdr->data, data, len);
req->nbytes += len;
}
rc = pmu_queue_request(req);
if (rc)
return rc;
wait_for_completion(&comp);
if (req->reply[0] == PMU_I2C_STATUS_OK)
break;
msleep(15);
}
if (req->reply[0] != PMU_I2C_STATUS_OK)
return -EIO;
for (retry = 0; retry < 16; retry++) {
memset(req, 0, sizeof(struct adb_request));
/* I know that looks like a lot, slow as hell, but darwin
* does it so let's be on the safe side for now
*/
msleep(15);
hdr->bus = PMU_I2C_BUS_STATUS;
INIT_COMPLETION(comp);
req->data[0] = PMU_I2C_CMD;
req->reply[0] = 0xff;
req->nbytes = 2;
req->done = pmu_i2c_complete;
req->arg = &comp;
rc = pmu_queue_request(req);
if (rc)
return rc;
wait_for_completion(&comp);
if (req->reply[0] == PMU_I2C_STATUS_OK && !read)
return 0;
if (req->reply[0] == PMU_I2C_STATUS_DATAREAD && read) {
int rlen = req->reply_len - 1;
if (rlen != len) {
printk(KERN_WARNING "low_i2c: PMU returned %d"
" bytes, expected %d !\n", rlen, len);
return -EIO;
}
if (len)
memcpy(data, &req->reply[1], len);
return 0;
}
}
return -EIO;
}
static void __init pmu_i2c_probe(void)
{
struct pmac_i2c_bus *bus;
struct device_node *busnode;
int channel, sz;
if (!pmu_present())
return;
/* There might or might not be a "pmu-i2c" node, we use that
* or via-pmu itself, whatever we find. I haven't seen a machine
* with separate bus nodes, so we assume a multibus setup
*/
busnode = of_find_node_by_name(NULL, "pmu-i2c");
if (busnode == NULL)
busnode = of_find_node_by_name(NULL, "via-pmu");
if (busnode == NULL)
return;
printk(KERN_INFO "PMU i2c %s\n", busnode->full_name);
/*
* We add bus 1 and 2 only for now, bus 0 is "special"
*/
for (channel = 1; channel <= 2; channel++) {
sz = sizeof(struct pmac_i2c_bus) + sizeof(struct adb_request);
bus = kzalloc(sz, GFP_KERNEL);
if (bus == NULL)
return;
bus->controller = busnode;
bus->busnode = busnode;
bus->type = pmac_i2c_bus_pmu;
bus->channel = channel;
bus->mode = pmac_i2c_mode_std;
bus->hostdata = bus + 1;
bus->xfer = pmu_i2c_xfer;
mutex_init(&bus->mutex);
bus->flags = pmac_i2c_multibus;
list_add(&bus->link, &pmac_i2c_busses);
printk(KERN_INFO " channel %d bus <multibus>\n", channel);
}
}
#endif /* CONFIG_ADB_PMU */
/*
*
* SMU implementation
*
*/
#ifdef CONFIG_PMAC_SMU
static void smu_i2c_complete(struct smu_i2c_cmd *cmd, void *misc)
{
complete(misc);
}
static int smu_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
u32 subaddr, u8 *data, int len)
{
struct smu_i2c_cmd *cmd = bus->hostdata;
struct completion comp;
int read = addrdir & 1;
int rc = 0;
if ((read && len > SMU_I2C_READ_MAX) ||
((!read) && len > SMU_I2C_WRITE_MAX))
return -EINVAL;
memset(cmd, 0, sizeof(struct smu_i2c_cmd));
cmd->info.bus = bus->channel;
cmd->info.devaddr = addrdir;
cmd->info.datalen = len;
switch(bus->mode) {
case pmac_i2c_mode_std:
if (subsize != 0)
return -EINVAL;
cmd->info.type = SMU_I2C_TRANSFER_SIMPLE;
break;
case pmac_i2c_mode_stdsub:
case pmac_i2c_mode_combined:
if (subsize > 3 || subsize < 1)
return -EINVAL;
cmd->info.sublen = subsize;
/* that's big-endian only but heh ! */
memcpy(&cmd->info.subaddr, ((char *)&subaddr) + (4 - subsize),
subsize);
if (bus->mode == pmac_i2c_mode_stdsub)
cmd->info.type = SMU_I2C_TRANSFER_STDSUB;
else
cmd->info.type = SMU_I2C_TRANSFER_COMBINED;
break;
default:
return -EINVAL;
}
if (!read && len)
memcpy(cmd->info.data, data, len);
init_completion(&comp);
cmd->done = smu_i2c_complete;
cmd->misc = &comp;
rc = smu_queue_i2c(cmd);
if (rc < 0)
return rc;
wait_for_completion(&comp);
rc = cmd->status;
if (read && len)
memcpy(data, cmd->info.data, len);
return rc < 0 ? rc : 0;
}
static void __init smu_i2c_probe(void)
{
struct device_node *controller, *busnode;
struct pmac_i2c_bus *bus;
const u32 *reg;
int sz;
if (!smu_present())
return;
controller = of_find_node_by_name(NULL, "smu-i2c-control");
if (controller == NULL)
controller = of_find_node_by_name(NULL, "smu");
if (controller == NULL)
return;
printk(KERN_INFO "SMU i2c %s\n", controller->full_name);
/* Look for childs, note that they might not be of the right
* type as older device trees mix i2c busses and other thigns
* at the same level
*/
for (busnode = NULL;
(busnode = of_get_next_child(controller, busnode)) != NULL;) {
if (strcmp(busnode->type, "i2c") &&
strcmp(busnode->type, "i2c-bus"))
continue;
reg = of_get_property(busnode, "reg", NULL);
if (reg == NULL)
continue;
sz = sizeof(struct pmac_i2c_bus) + sizeof(struct smu_i2c_cmd);
bus = kzalloc(sz, GFP_KERNEL);
if (bus == NULL)
return;
bus->controller = controller;
bus->busnode = of_node_get(busnode);
bus->type = pmac_i2c_bus_smu;
bus->channel = *reg;
bus->mode = pmac_i2c_mode_std;
bus->hostdata = bus + 1;
bus->xfer = smu_i2c_xfer;
mutex_init(&bus->mutex);
bus->flags = 0;
list_add(&bus->link, &pmac_i2c_busses);
printk(KERN_INFO " channel %x bus %s\n",
bus->channel, busnode->full_name);
}
}
#endif /* CONFIG_PMAC_SMU */
/*
*
* Core code
*
*/
struct pmac_i2c_bus *pmac_i2c_find_bus(struct device_node *node)
{
struct device_node *p = of_node_get(node);
struct device_node *prev = NULL;
struct pmac_i2c_bus *bus;
while(p) {
list_for_each_entry(bus, &pmac_i2c_busses, link) {
if (p == bus->busnode) {
if (prev && bus->flags & pmac_i2c_multibus) {
const u32 *reg;
reg = of_get_property(prev, "reg",
NULL);
if (!reg)
continue;
if (((*reg) >> 8) != bus->channel)
continue;
}
of_node_put(p);
of_node_put(prev);
return bus;
}
}
of_node_put(prev);
prev = p;
p = of_get_parent(p);
}
return NULL;
}
EXPORT_SYMBOL_GPL(pmac_i2c_find_bus);
u8 pmac_i2c_get_dev_addr(struct device_node *device)
{
const u32 *reg = of_get_property(device, "reg", NULL);
if (reg == NULL)
return 0;
return (*reg) & 0xff;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_dev_addr);
struct device_node *pmac_i2c_get_controller(struct pmac_i2c_bus *bus)
{
return bus->controller;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_controller);
struct device_node *pmac_i2c_get_bus_node(struct pmac_i2c_bus *bus)
{
return bus->busnode;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_bus_node);
int pmac_i2c_get_type(struct pmac_i2c_bus *bus)
{
return bus->type;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_type);
int pmac_i2c_get_flags(struct pmac_i2c_bus *bus)
{
return bus->flags;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_flags);
int pmac_i2c_get_channel(struct pmac_i2c_bus *bus)
{
return bus->channel;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_channel);
void pmac_i2c_attach_adapter(struct pmac_i2c_bus *bus,
struct i2c_adapter *adapter)
{
WARN_ON(bus->adapter != NULL);
bus->adapter = adapter;
}
EXPORT_SYMBOL_GPL(pmac_i2c_attach_adapter);
void pmac_i2c_detach_adapter(struct pmac_i2c_bus *bus,
struct i2c_adapter *adapter)
{
WARN_ON(bus->adapter != adapter);
bus->adapter = NULL;
}
EXPORT_SYMBOL_GPL(pmac_i2c_detach_adapter);
struct i2c_adapter *pmac_i2c_get_adapter(struct pmac_i2c_bus *bus)
{
return bus->adapter;
}
EXPORT_SYMBOL_GPL(pmac_i2c_get_adapter);
struct pmac_i2c_bus *pmac_i2c_adapter_to_bus(struct i2c_adapter *adapter)
{
struct pmac_i2c_bus *bus;
list_for_each_entry(bus, &pmac_i2c_busses, link)
if (bus->adapter == adapter)
return bus;
return NULL;
}
EXPORT_SYMBOL_GPL(pmac_i2c_adapter_to_bus);
int pmac_i2c_match_adapter(struct device_node *dev, struct i2c_adapter *adapter)
{
struct pmac_i2c_bus *bus = pmac_i2c_find_bus(dev);
if (bus == NULL)
return 0;
return (bus->adapter == adapter);
}
EXPORT_SYMBOL_GPL(pmac_i2c_match_adapter);
int pmac_low_i2c_lock(struct device_node *np)
{
struct pmac_i2c_bus *bus, *found = NULL;
list_for_each_entry(bus, &pmac_i2c_busses, link) {
if (np == bus->controller) {
found = bus;
break;
}
}
if (!found)
return -ENODEV;
return pmac_i2c_open(bus, 0);
}
EXPORT_SYMBOL_GPL(pmac_low_i2c_lock);
int pmac_low_i2c_unlock(struct device_node *np)
{
struct pmac_i2c_bus *bus, *found = NULL;
list_for_each_entry(bus, &pmac_i2c_busses, link) {
if (np == bus->controller) {
found = bus;
break;
}
}
if (!found)
return -ENODEV;
pmac_i2c_close(bus);
return 0;
}
EXPORT_SYMBOL_GPL(pmac_low_i2c_unlock);
int pmac_i2c_open(struct pmac_i2c_bus *bus, int polled)
{
int rc;
mutex_lock(&bus->mutex);
bus->polled = polled || pmac_i2c_force_poll;
bus->opened = 1;
bus->mode = pmac_i2c_mode_std;
if (bus->open && (rc = bus->open(bus)) != 0) {
bus->opened = 0;
mutex_unlock(&bus->mutex);
return rc;
}
return 0;
}
EXPORT_SYMBOL_GPL(pmac_i2c_open);
void pmac_i2c_close(struct pmac_i2c_bus *bus)
{
WARN_ON(!bus->opened);
if (bus->close)
bus->close(bus);
bus->opened = 0;
mutex_unlock(&bus->mutex);
}
EXPORT_SYMBOL_GPL(pmac_i2c_close);
int pmac_i2c_setmode(struct pmac_i2c_bus *bus, int mode)
{
WARN_ON(!bus->opened);
/* Report me if you see the error below as there might be a new
* "combined4" mode that I need to implement for the SMU bus
*/
if (mode < pmac_i2c_mode_dumb || mode > pmac_i2c_mode_combined) {
printk(KERN_ERR "low_i2c: Invalid mode %d requested on"
" bus %s !\n", mode, bus->busnode->full_name);
return -EINVAL;
}
bus->mode = mode;
return 0;
}
EXPORT_SYMBOL_GPL(pmac_i2c_setmode);
int pmac_i2c_xfer(struct pmac_i2c_bus *bus, u8 addrdir, int subsize,
u32 subaddr, u8 *data, int len)
{
int rc;
WARN_ON(!bus->opened);
DBG("xfer() chan=%d, addrdir=0x%x, mode=%d, subsize=%d, subaddr=0x%x,"
" %d bytes, bus %s\n", bus->channel, addrdir, bus->mode, subsize,
subaddr, len, bus->busnode->full_name);
rc = bus->xfer(bus, addrdir, subsize, subaddr, data, len);
#ifdef DEBUG
if (rc)
DBG("xfer error %d\n", rc);
#endif
return rc;
}
EXPORT_SYMBOL_GPL(pmac_i2c_xfer);
/* some quirks for platform function decoding */
enum {
pmac_i2c_quirk_invmask = 0x00000001u,
pmac_i2c_quirk_skip = 0x00000002u,
};
static void pmac_i2c_devscan(void (*callback)(struct device_node *dev,
int quirks))
{
struct pmac_i2c_bus *bus;
struct device_node *np;
static struct whitelist_ent {
char *name;
char *compatible;
int quirks;
} whitelist[] = {
/* XXX Study device-tree's & apple drivers are get the quirks
* right !
*/
/* Workaround: It seems that running the clockspreading
* properties on the eMac will cause lockups during boot.
* The machine seems to work fine without that. So for now,
* let's make sure i2c-hwclock doesn't match about "imic"
* clocks and we'll figure out if we really need to do
* something special about those later.
*/
{ "i2c-hwclock", "imic5002", pmac_i2c_quirk_skip },
{ "i2c-hwclock", "imic5003", pmac_i2c_quirk_skip },
{ "i2c-hwclock", NULL, pmac_i2c_quirk_invmask },
{ "i2c-cpu-voltage", NULL, 0},
{ "temp-monitor", NULL, 0 },
{ "supply-monitor", NULL, 0 },
{ NULL, NULL, 0 },
};
/* Only some devices need to have platform functions instanciated
* here. For now, we have a table. Others, like 9554 i2c GPIOs used
* on Xserve, if we ever do a driver for them, will use their own
* platform function instance
*/
list_for_each_entry(bus, &pmac_i2c_busses, link) {
for (np = NULL;
(np = of_get_next_child(bus->busnode, np)) != NULL;) {
struct whitelist_ent *p;
/* If multibus, check if device is on that bus */
if (bus->flags & pmac_i2c_multibus)
if (bus != pmac_i2c_find_bus(np))
continue;
for (p = whitelist; p->name != NULL; p++) {
if (strcmp(np->name, p->name))
continue;
if (p->compatible &&
!of_device_is_compatible(np, p->compatible))
continue;
if (p->quirks & pmac_i2c_quirk_skip)
break;
callback(np, p->quirks);
break;
}
}
}
}
#define MAX_I2C_DATA 64
struct pmac_i2c_pf_inst
{
struct pmac_i2c_bus *bus;
u8 addr;
u8 buffer[MAX_I2C_DATA];
u8 scratch[MAX_I2C_DATA];
int bytes;
int quirks;
};
static void* pmac_i2c_do_begin(struct pmf_function *func, struct pmf_args *args)
{
struct pmac_i2c_pf_inst *inst;
struct pmac_i2c_bus *bus;
bus = pmac_i2c_find_bus(func->node);
if (bus == NULL) {
printk(KERN_ERR "low_i2c: Can't find bus for %s (pfunc)\n",
func->node->full_name);
return NULL;
}
if (pmac_i2c_open(bus, 0)) {
printk(KERN_ERR "low_i2c: Can't open i2c bus for %s (pfunc)\n",
func->node->full_name);
return NULL;
}
/* XXX might need GFP_ATOMIC when called during the suspend process,
* but then, there are already lots of issues with suspending when
* near OOM that need to be resolved, the allocator itself should
* probably make GFP_NOIO implicit during suspend
*/
inst = kzalloc(sizeof(struct pmac_i2c_pf_inst), GFP_KERNEL);
if (inst == NULL) {
pmac_i2c_close(bus);
return NULL;
}
inst->bus = bus;
inst->addr = pmac_i2c_get_dev_addr(func->node);
inst->quirks = (int)(long)func->driver_data;
return inst;
}
static void pmac_i2c_do_end(struct pmf_function *func, void *instdata)
{
struct pmac_i2c_pf_inst *inst = instdata;
if (inst == NULL)
return;
pmac_i2c_close(inst->bus);
if (inst)
kfree(inst);
}
static int pmac_i2c_do_read(PMF_STD_ARGS, u32 len)
{
struct pmac_i2c_pf_inst *inst = instdata;
inst->bytes = len;
return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 0, 0,
inst->buffer, len);
}
static int pmac_i2c_do_write(PMF_STD_ARGS, u32 len, const u8 *data)
{
struct pmac_i2c_pf_inst *inst = instdata;
return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
(u8 *)data, len);
}
/* This function is used to do the masking & OR'ing for the "rmw" type
* callbacks. Ze should apply the mask and OR in the values in the
* buffer before writing back. The problem is that it seems that
* various darwin drivers implement the mask/or differently, thus
* we need to check the quirks first
*/
static void pmac_i2c_do_apply_rmw(struct pmac_i2c_pf_inst *inst,
u32 len, const u8 *mask, const u8 *val)
{
int i;
if (inst->quirks & pmac_i2c_quirk_invmask) {
for (i = 0; i < len; i ++)
inst->scratch[i] = (inst->buffer[i] & mask[i]) | val[i];
} else {
for (i = 0; i < len; i ++)
inst->scratch[i] = (inst->buffer[i] & ~mask[i])
| (val[i] & mask[i]);
}
}
static int pmac_i2c_do_rmw(PMF_STD_ARGS, u32 masklen, u32 valuelen,
u32 totallen, const u8 *maskdata,
const u8 *valuedata)
{
struct pmac_i2c_pf_inst *inst = instdata;
if (masklen > inst->bytes || valuelen > inst->bytes ||
totallen > inst->bytes || valuelen > masklen)
return -EINVAL;
pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 0, 0,
inst->scratch, totallen);
}
static int pmac_i2c_do_read_sub(PMF_STD_ARGS, u8 subaddr, u32 len)
{
struct pmac_i2c_pf_inst *inst = instdata;
inst->bytes = len;
return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_read, 1, subaddr,
inst->buffer, len);
}
static int pmac_i2c_do_write_sub(PMF_STD_ARGS, u8 subaddr, u32 len,
const u8 *data)
{
struct pmac_i2c_pf_inst *inst = instdata;
return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
subaddr, (u8 *)data, len);
}
static int pmac_i2c_do_set_mode(PMF_STD_ARGS, int mode)
{
struct pmac_i2c_pf_inst *inst = instdata;
return pmac_i2c_setmode(inst->bus, mode);
}
static int pmac_i2c_do_rmw_sub(PMF_STD_ARGS, u8 subaddr, u32 masklen,
u32 valuelen, u32 totallen, const u8 *maskdata,
const u8 *valuedata)
{
struct pmac_i2c_pf_inst *inst = instdata;
if (masklen > inst->bytes || valuelen > inst->bytes ||
totallen > inst->bytes || valuelen > masklen)
return -EINVAL;
pmac_i2c_do_apply_rmw(inst, masklen, maskdata, valuedata);
return pmac_i2c_xfer(inst->bus, inst->addr | pmac_i2c_write, 1,
subaddr, inst->scratch, totallen);
}
static int pmac_i2c_do_mask_and_comp(PMF_STD_ARGS, u32 len,
const u8 *maskdata,
const u8 *valuedata)
{
struct pmac_i2c_pf_inst *inst = instdata;
int i, match;
/* Get return value pointer, it's assumed to be a u32 */
if (!args || !args->count || !args->u[0].p)
return -EINVAL;
/* Check buffer */
if (len > inst->bytes)
return -EINVAL;
for (i = 0, match = 1; match && i < len; i ++)
if ((inst->buffer[i] & maskdata[i]) != valuedata[i])
match = 0;
*args->u[0].p = match;
return 0;
}
static int pmac_i2c_do_delay(PMF_STD_ARGS, u32 duration)
{
msleep((duration + 999) / 1000);
return 0;
}
static struct pmf_handlers pmac_i2c_pfunc_handlers = {
.begin = pmac_i2c_do_begin,
.end = pmac_i2c_do_end,
.read_i2c = pmac_i2c_do_read,
.write_i2c = pmac_i2c_do_write,
.rmw_i2c = pmac_i2c_do_rmw,
.read_i2c_sub = pmac_i2c_do_read_sub,
.write_i2c_sub = pmac_i2c_do_write_sub,
.rmw_i2c_sub = pmac_i2c_do_rmw_sub,
.set_i2c_mode = pmac_i2c_do_set_mode,
.mask_and_compare = pmac_i2c_do_mask_and_comp,
.delay = pmac_i2c_do_delay,
};
static void __init pmac_i2c_dev_create(struct device_node *np, int quirks)
{
DBG("dev_create(%s)\n", np->full_name);
pmf_register_driver(np, &pmac_i2c_pfunc_handlers,
(void *)(long)quirks);
}
static void __init pmac_i2c_dev_init(struct device_node *np, int quirks)
{
DBG("dev_create(%s)\n", np->full_name);
pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_INIT, NULL);
}
static void pmac_i2c_dev_suspend(struct device_node *np, int quirks)
{
DBG("dev_suspend(%s)\n", np->full_name);
pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_SLEEP, NULL);
}
static void pmac_i2c_dev_resume(struct device_node *np, int quirks)
{
DBG("dev_resume(%s)\n", np->full_name);
pmf_do_functions(np, NULL, 0, PMF_FLAGS_ON_WAKE, NULL);
}
void pmac_pfunc_i2c_suspend(void)
{
pmac_i2c_devscan(pmac_i2c_dev_suspend);
}
void pmac_pfunc_i2c_resume(void)
{
pmac_i2c_devscan(pmac_i2c_dev_resume);
}
/*
* Initialize us: probe all i2c busses on the machine, instantiate
* busses and platform functions as needed.
*/
/* This is non-static as it might be called early by smp code */
int __init pmac_i2c_init(void)
{
static int i2c_inited;
if (i2c_inited)
return 0;
i2c_inited = 1;
if (!machine_is(powermac))
return 0;
/* Probe keywest-i2c busses */
kw_i2c_probe();
#ifdef CONFIG_ADB_PMU
/* Probe PMU i2c busses */
pmu_i2c_probe();
#endif
#ifdef CONFIG_PMAC_SMU
/* Probe SMU i2c busses */
smu_i2c_probe();
#endif
/* Now add plaform functions for some known devices */
pmac_i2c_devscan(pmac_i2c_dev_create);
return 0;
}
arch_initcall(pmac_i2c_init);
/* Since pmac_i2c_init can be called too early for the platform device
* registration, we need to do it at a later time. In our case, subsys
* happens to fit well, though I agree it's a bit of a hack...
*/
static int __init pmac_i2c_create_platform_devices(void)
{
struct pmac_i2c_bus *bus;
int i = 0;
/* In the case where we are initialized from smp_init(), we must
* not use the timer (and thus the irq). It's safe from now on
* though
*/
pmac_i2c_force_poll = 0;
/* Create platform devices */
list_for_each_entry(bus, &pmac_i2c_busses, link) {
bus->platform_dev =
platform_device_alloc("i2c-powermac", i++);
if (bus->platform_dev == NULL)
return -ENOMEM;
bus->platform_dev->dev.platform_data = bus;
platform_device_add(bus->platform_dev);
}
/* Now call platform "init" functions */
pmac_i2c_devscan(pmac_i2c_dev_init);
return 0;
}
subsys_initcall(pmac_i2c_create_platform_devices);
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