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linux/arch/powerpc/platforms/powermac/low_i2c.c
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00

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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 <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 semaphore sem;
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 semaphore 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;
down(&host->mutex);
return 0;
}
static void kw_i2c_close(struct pmac_i2c_bus *bus)
{
struct pmac_i2c_host_kw *host = bus->hostdata;
up(&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 = 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;
}
init_MUTEX(&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 = 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 = 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;
init_MUTEX(&bus->sem);
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 = 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;
init_MUTEX(&bus->sem);
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 = 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;
init_MUTEX(&bus->sem);
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 = 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 = 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;
down(&bus->sem);
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;
up(&bus->sem);
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;
up(&bus->sem);
}
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 &&
!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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