low_i2c.c

linux内核源码

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);