[PATCH] CRIS update: I/O and DMA allocator

Added I/O and DMA allocators to be used by drivers.

Signed-off-by: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 879 insertions, 0 deletions

diff --git a/arch/cris/arch-v10/kernel/io_interface_mux.c b/arch/cris/arch-v10/kernel/io_interface_mux.c
new file mode 100644
index 0000000..29d48ad
--- /dev/null
+++ b/arch/cris/arch-v10/kernel/io_interface_mux.c
@@ -0,0 +1,879 @@
+/* IO interface mux allocator for ETRAX100LX.
+ * Copyright 2004, Axis Communications AB
+ * $Id: io_interface_mux.c,v 1.2 2004/12/21 12:08:38 starvik Exp $
+ */
+
+
+/* C.f. ETRAX100LX Designer's Reference 20.9 */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <asm/arch/svinto.h>
+#include <asm/io.h>
+#include <asm/arch/io_interface_mux.h>
+
+
+#define DBG(s)
+
+/* Macro to access ETRAX 100 registers */
+#define SETS(var, reg, field, val) var = (var & ~IO_MASK_(reg##_, field##_)) | \
+					  IO_STATE_(reg##_, field##_, _##val)
+
+enum io_if_group {
+	group_a = (1<<0),
+	group_b = (1<<1),
+	group_c = (1<<2),
+	group_d = (1<<3),
+	group_e = (1<<4),
+	group_f = (1<<5)
+};
+
+struct watcher
+{
+	void (*notify)(const unsigned int gpio_in_available,
+		       const unsigned int gpio_out_available,
+		       const unsigned char pa_available,
+		       const unsigned char pb_available);
+	struct watcher *next;
+};
+
+
+struct if_group
+{
+	enum io_if_group        group;
+	unsigned char           used;
+	enum cris_io_interface  owner;
+};
+
+
+struct interface
+{
+	enum cris_io_interface   ioif;
+	unsigned char            groups;
+	unsigned char            used;
+	char                    *owner;
+	unsigned int             gpio_g_in;
+	unsigned int             gpio_g_out;
+	unsigned char            gpio_b;
+};
+
+static struct if_group if_groups[6] = {
+	{
+		.group = group_a,
+		.used = 0,
+	},
+	{
+		.group = group_b,
+		.used = 0,
+	},
+	{
+		.group = group_c,
+		.used = 0,
+	},
+	{
+		.group = group_d,
+		.used = 0,
+	},
+	{
+		.group = group_e,
+		.used = 0,
+	},
+	{
+		.group = group_f,
+		.used = 0,
+	}
+};
+
+/* The order in the array must match the order of enum
+ * cris_io_interface in io_interface_mux.h */
+static struct interface interfaces[] = {
+	/* Begin Non-multiplexed interfaces */
+	{
+		.ioif = if_eth,
+		.groups = 0,
+		.gpio_g_in = 0,
+		.gpio_g_out = 0,
+		.gpio_b = 0
+	},
+	{
+		.ioif = if_serial_0,
+		.groups = 0,
+		.gpio_g_in = 0,
+		.gpio_g_out = 0,
+		.gpio_b = 0
+	},
+	/* End Non-multiplexed interfaces */
+	{
+		.ioif = if_serial_1,
+		.groups = group_e,
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_serial_2,
+		.groups = group_b,
+		.gpio_g_in =  0x000000c0,
+		.gpio_g_out = 0x000000c0,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_serial_3,
+		.groups = group_c,
+		.gpio_g_in =  0xc0000000,
+		.gpio_g_out = 0xc0000000,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_sync_serial_1,
+		.groups = group_e | group_f, /* if_sync_serial_1 and if_sync_serial_3
+					       can be used simultaneously */
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0x10
+	},
+	{
+		.ioif = if_sync_serial_3,
+		.groups = group_c | group_f,
+		.gpio_g_in =  0xc0000000,
+		.gpio_g_out = 0xc0000000,
+		.gpio_b = 0x80
+	},
+	{
+		.ioif = if_shared_ram,
+		.groups = group_a,
+		.gpio_g_in =  0x0000ff3e,
+		.gpio_g_out = 0x0000ff38,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_shared_ram_w,
+		.groups = group_a | group_d,
+		.gpio_g_in =  0x00ffff3e,
+		.gpio_g_out = 0x00ffff38,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_par_0,
+		.groups = group_a,
+		.gpio_g_in =  0x0000ff3e,
+		.gpio_g_out = 0x0000ff3e,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_par_1,
+		.groups = group_d,
+		.gpio_g_in =  0x3eff0000,
+		.gpio_g_out = 0x3eff0000,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_par_w,
+		.groups = group_a | group_d,
+		.gpio_g_in =  0x00ffff3e,
+		.gpio_g_out = 0x00ffff3e,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_scsi8_0,
+		.groups = group_a | group_b | group_f, /* if_scsi8_0 and if_scsi8_1
+							  can be used simultaneously */
+		.gpio_g_in =  0x0000ffff,
+		.gpio_g_out = 0x0000ffff,
+		.gpio_b = 0x10
+	},
+	{
+		.ioif = if_scsi8_1,
+		.groups = group_c | group_d | group_f, /* if_scsi8_0 and if_scsi8_1
+							  can be used simultaneously */
+		.gpio_g_in =  0xffff0000,
+		.gpio_g_out = 0xffff0000,
+		.gpio_b = 0x80
+	},
+	{
+		.ioif = if_scsi_w,
+		.groups = group_a | group_b | group_d | group_f,
+		.gpio_g_in =  0x01ffffff,
+		.gpio_g_out = 0x07ffffff,
+		.gpio_b = 0x80
+	},
+	{
+		.ioif = if_ata,
+		.groups = group_a | group_b | group_c | group_d,
+		.gpio_g_in =  0xf9ffffff,
+		.gpio_g_out = 0xffffffff,
+		.gpio_b = 0x80
+	},
+	{
+		.ioif = if_csp,
+		.groups = group_f, /* if_csp and if_i2c can be used simultaneously */
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0xfc
+	},
+	{
+		.ioif = if_i2c,
+		.groups = group_f, /* if_csp and if_i2c can be used simultaneously */
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0x03
+	},
+	{
+		.ioif = if_usb_1,
+		.groups = group_e | group_f,
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0x2c
+	},
+	{
+		.ioif = if_usb_2,
+		.groups = group_d,
+		.gpio_g_in =  0x0e000000,
+		.gpio_g_out = 0x3c000000,
+		.gpio_b = 0x00
+	},
+	/* GPIO pins */
+	{
+		.ioif = if_gpio_grp_a,
+		.groups = group_a,
+		.gpio_g_in =  0x0000ff3f,
+		.gpio_g_out = 0x0000ff3f,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_gpio_grp_b,
+		.groups = group_b,
+		.gpio_g_in =  0x000000c0,
+		.gpio_g_out = 0x000000c0,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_gpio_grp_c,
+		.groups = group_c,
+		.gpio_g_in =  0xc0000000,
+		.gpio_g_out = 0xc0000000,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_gpio_grp_d,
+		.groups = group_d,
+		.gpio_g_in =  0x3fff0000,
+		.gpio_g_out = 0x3fff0000,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_gpio_grp_e,
+		.groups = group_e,
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0x00
+	},
+	{
+		.ioif = if_gpio_grp_f,
+		.groups = group_f,
+		.gpio_g_in =  0x00000000,
+		.gpio_g_out = 0x00000000,
+		.gpio_b = 0xff
+	}
+	/* Array end */
+};
+
+static struct watcher *watchers = NULL;
+
+static unsigned int gpio_in_pins =  0xffffffff;
+static unsigned int gpio_out_pins = 0xffffffff;
+static unsigned char gpio_pb_pins = 0xff;
+static unsigned char gpio_pa_pins = 0xff;
+
+static enum cris_io_interface gpio_pa_owners[8];
+static enum cris_io_interface gpio_pb_owners[8];
+static enum cris_io_interface gpio_pg_owners[32];
+
+static int cris_io_interface_init(void);
+
+static unsigned char clear_group_from_set(const unsigned char groups, struct if_group *group)
+{
+	return (groups & ~group->group);
+}
+
+
+static struct if_group *get_group(const unsigned char groups)
+{
+	int i;
+	for (i = 0; i < sizeof(if_groups)/sizeof(struct if_group); i++) {
+		if (groups & if_groups[i].group) {
+			return &if_groups[i];
+		}
+	}
+	return NULL;
+}
+
+
+static void notify_watchers(void)
+{
+	struct watcher *w = watchers;
+
+	DBG(printk("io_interface_mux: notifying watchers\n"));
+
+	while (NULL != w) {
+		w->notify((const unsigned int)gpio_in_pins,
+			  (const unsigned int)gpio_out_pins,
+			  (const unsigned char)gpio_pa_pins,
+			  (const unsigned char)gpio_pb_pins);
+		w = w->next;
+	}
+}
+
+
+int cris_request_io_interface(enum cris_io_interface ioif, const char *device_id)
+{
+	int set_gen_config = 0;
+	int set_gen_config_ii = 0;
+	unsigned long int gens;
+	unsigned long int gens_ii;
+	struct if_group *grp;
+	unsigned char group_set;
+	unsigned long flags;
+
+	(void)cris_io_interface_init();
+
+	DBG(printk("cris_request_io_interface(%d, \"%s\")\n", ioif, device_id));
+
+	if ((ioif >= if_max_interfaces) || (ioif < 0)) {
+		printk(KERN_CRIT "cris_request_io_interface: Bad interface %u submitted for %s\n",
+		       ioif,
+		       device_id);
+		return -EINVAL;
+	}
+
+	local_irq_save(flags);
+
+	if (interfaces[ioif].used) {
+		local_irq_restore(flags);
+		printk(KERN_CRIT "cris_io_interface: Cannot allocate interface for %s, in use by %s\n",
+		       device_id,
+		       interfaces[ioif].owner);
+		return -EBUSY;
+	}
+
+	/* Check that all required groups are free before allocating, */
+	group_set = interfaces[ioif].groups;
+	while (NULL != (grp = get_group(group_set))) {
+		if (grp->used) {
+			if (grp->group == group_f) {
+				if ((if_sync_serial_1 ==  ioif) ||
+				    (if_sync_serial_3 ==  ioif)) {
+					if ((grp->owner != if_sync_serial_1) &&
+					    (grp->owner != if_sync_serial_3)) {
+						local_irq_restore(flags);
+						return -EBUSY;
+					}
+				} else if ((if_scsi8_0 == ioif) ||
+					   (if_scsi8_1 == ioif)) {
+					if ((grp->owner != if_scsi8_0) &&
+					    (grp->owner != if_scsi8_1)) {
+						local_irq_restore(flags);
+						return -EBUSY;
+					}
+				}
+			} else {
+				local_irq_restore(flags);
+				return -EBUSY;
+			}
+		}
+		group_set = clear_group_from_set(group_set, grp);
+	}
+
+	/* Are the required GPIO pins available too? */
+	if (((interfaces[ioif].gpio_g_in & gpio_in_pins) != interfaces[ioif].gpio_g_in) ||
+	    ((interfaces[ioif].gpio_g_out & gpio_out_pins) != interfaces[ioif].gpio_g_out) ||
+	    ((interfaces[ioif].gpio_b & gpio_pb_pins) != interfaces[ioif].gpio_b)) {
+		printk(KERN_CRIT "cris_request_io_interface: Could not get required pins for interface %u\n",
+		       ioif);
+		return -EBUSY;
+	}
+
+	/* All needed I/O pins and pin groups are free, allocate. */
+	group_set = interfaces[ioif].groups;
+	while (NULL != (grp = get_group(group_set))) {
+		grp->used = 1;
+		grp->owner = ioif;
+		group_set = clear_group_from_set(group_set, grp);
+	}
+
+	gens = genconfig_shadow;
+	gens_ii = gen_config_ii_shadow;
+
+	set_gen_config = 1;
+	switch (ioif)
+	{
+	/* Begin Non-multiplexed interfaces */
+	case if_eth:
+		/* fall through */
+	case if_serial_0:
+		set_gen_config = 0;
+		break;
+	/* End Non-multiplexed interfaces */
+	case if_serial_1:
+		set_gen_config_ii = 1;
+		SETS(gens_ii, R_GEN_CONFIG_II, sermode1, async);
+		break;
+	case if_serial_2:
+		SETS(gens, R_GEN_CONFIG, ser2, select);
+		break;
+	case if_serial_3:
+		SETS(gens, R_GEN_CONFIG, ser3, select);
+		set_gen_config_ii = 1;
+		SETS(gens_ii, R_GEN_CONFIG_II, sermode3, async);
+		break;
+	case if_sync_serial_1:
+		set_gen_config_ii = 1;
+		SETS(gens_ii, R_GEN_CONFIG_II, sermode1, sync);
+		break;
+	case if_sync_serial_3:
+		SETS(gens, R_GEN_CONFIG, ser3, select);
+		set_gen_config_ii = 1;
+		SETS(gens_ii, R_GEN_CONFIG_II, sermode3, sync);
+		break;
+	case if_shared_ram:
+		SETS(gens, R_GEN_CONFIG, mio, select);
+		break;
+	case if_shared_ram_w:
+		SETS(gens, R_GEN_CONFIG, mio_w, select);
+		break;
+	case if_par_0:
+		SETS(gens, R_GEN_CONFIG, par0, select);
+		break;
+	case if_par_1:
+		SETS(gens, R_GEN_CONFIG, par1, select);
+		break;
+	case if_par_w:
+		SETS(gens, R_GEN_CONFIG, par0, select);
+		SETS(gens, R_GEN_CONFIG, par_w, select);
+		break;
+	case if_scsi8_0:
+		SETS(gens, R_GEN_CONFIG, scsi0, select);
+		break;
+	case if_scsi8_1:
+		SETS(gens, R_GEN_CONFIG, scsi1, select);
+		break;
+	case if_scsi_w:
+		SETS(gens, R_GEN_CONFIG, scsi0, select);
+		SETS(gens, R_GEN_CONFIG, scsi0w, select);
+		break;
+	case if_ata:
+		SETS(gens, R_GEN_CONFIG, ata, select);
+		break;
+	case if_csp:
+		/* fall through */
+	case if_i2c:
+		set_gen_config = 0;
+		break;
+	case if_usb_1:
+		SETS(gens, R_GEN_CONFIG, usb1, select);
+		break;
+	case if_usb_2:
+		SETS(gens, R_GEN_CONFIG, usb2, select);
+		break;
+	case if_gpio_grp_a:
+		/* GPIO groups are only accounted, don't do configuration changes. */
+		/* fall through */
+	case if_gpio_grp_b:
+		/* fall through */
+	case if_gpio_grp_c:
+		/* fall through */
+	case if_gpio_grp_d:
+		/* fall through */
+	case if_gpio_grp_e:
+		/* fall through */
+	case if_gpio_grp_f:
+		set_gen_config = 0;
+		break;
+	default:
+		panic("cris_request_io_interface: Bad interface %u submitted for %s\n",
+		      ioif,
+		      device_id);
+	}
+
+	interfaces[ioif].used = 1;
+	interfaces[ioif].owner = (char*)device_id;
+
+	if (set_gen_config) {
+		volatile int i;
+		genconfig_shadow = gens;
+		*R_GEN_CONFIG = genconfig_shadow;
+		/* Wait 12 cycles before doing any DMA command */
+		for(i = 6; i > 0; i--)
+			nop();
+	}
+	if (set_gen_config_ii) {
+		gen_config_ii_shadow = gens_ii;
+		*R_GEN_CONFIG_II = gen_config_ii_shadow;
+	}
+
+	DBG(printk("GPIO pins: available before: g_in=0x%08x g_out=0x%08x pb=0x%02x\n",
+		   gpio_in_pins, gpio_out_pins, gpio_pb_pins));
+	DBG(printk("grabbing pins: g_in=0x%08x g_out=0x%08x pb=0x%02x\n",
+		   interfaces[ioif].gpio_g_in,
+		   interfaces[ioif].gpio_g_out,
+		   interfaces[ioif].gpio_b));
+
+	gpio_in_pins &= ~interfaces[ioif].gpio_g_in;
+	gpio_out_pins &= ~interfaces[ioif].gpio_g_out;
+	gpio_pb_pins &= ~interfaces[ioif].gpio_b;
+
+	DBG(printk("GPIO pins: available after: g_in=0x%08x g_out=0x%08x pb=0x%02x\n",
+		   gpio_in_pins, gpio_out_pins, gpio_pb_pins));
+
+	local_irq_restore(flags);
+
+	notify_watchers();
+
+	return 0;
+}
+
+
+void cris_free_io_interface(enum cris_io_interface ioif)
+{
+	struct if_group *grp;
+	unsigned char group_set;
+	unsigned long flags;
+
+	(void)cris_io_interface_init();
+
+	if ((ioif >= if_max_interfaces) || (ioif < 0)) {
+		printk(KERN_CRIT "cris_free_io_interface: Bad interface %u\n",
+		       ioif);
+		return;
+	}
+	local_irq_save(flags);
+	if (!interfaces[ioif].used) {
+		printk(KERN_CRIT "cris_free_io_interface: Freeing free interface %u\n",
+		       ioif);
+		local_irq_restore(flags);
+		return;
+	}
+	group_set = interfaces[ioif].groups;
+	while (NULL != (grp = get_group(group_set))) {
+		if (grp->group == group_f) {
+			switch (ioif)
+			{
+			case if_sync_serial_1:
+				if ((grp->owner == if_sync_serial_1) &&
+				    interfaces[if_sync_serial_3].used) {
+					grp->owner = if_sync_serial_3;
+				} else
+					grp->used = 0;
+				break;
+			case if_sync_serial_3:
+				if ((grp->owner == if_sync_serial_3) &&
+				    interfaces[if_sync_serial_1].used) {
+					grp->owner = if_sync_serial_1;
+				} else
+					grp->used = 0;
+				break;
+			case if_scsi8_0:
+				if ((grp->owner == if_scsi8_0) &&
+				    interfaces[if_scsi8_1].used) {
+					grp->owner = if_scsi8_1;
+				} else
+					grp->used = 0;
+				break;
+			case if_scsi8_1:
+				if ((grp->owner == if_scsi8_1) &&
+				    interfaces[if_scsi8_0].used) {
+					grp->owner = if_scsi8_0;
+				} else
+					grp->used = 0;
+				break;
+			default:
+				grp->used = 0;
+			}
+		} else {
+			grp->used = 0;
+		}
+		group_set = clear_group_from_set(group_set, grp);
+	}
+	interfaces[ioif].used = 0;
+	interfaces[ioif].owner = NULL;
+
+	DBG(printk("GPIO pins: available before: g_in=0x%08x g_out=0x%08x pb=0x%02x\n",
+		   gpio_in_pins, gpio_out_pins, gpio_pb_pins));
+	DBG(printk("freeing pins: g_in=0x%08x g_out=0x%08x pb=0x%02x\n",
+		   interfaces[ioif].gpio_g_in,
+		   interfaces[ioif].gpio_g_out,
+		   interfaces[ioif].gpio_b));
+
+	gpio_in_pins |= interfaces[ioif].gpio_g_in;
+	gpio_out_pins |= interfaces[ioif].gpio_g_out;
+	gpio_pb_pins |= interfaces[ioif].gpio_b;
+
+	DBG(printk("GPIO pins: available after: g_in=0x%08x g_out=0x%08x pb=0x%02x\n",
+		   gpio_in_pins, gpio_out_pins, gpio_pb_pins));
+
+	local_irq_restore(flags);
+
+	notify_watchers();
+}
+
+/* Create a bitmask from bit 0 (inclusive) to bit stop_bit
+   (non-inclusive).  stop_bit == 0 returns 0x0 */
+static inline unsigned int create_mask(const unsigned stop_bit)
+{
+	/* Avoid overflow */
+	if (stop_bit >= 32) {
+		return 0xffffffff;
+	}
+	return (1<<stop_bit)-1;
+}
+
+
+/* port can be 'a', 'b' or 'g' */
+int cris_io_interface_allocate_pins(const enum cris_io_interface ioif,
+				    const char port,
+				    const unsigned start_bit,
+				    const unsigned stop_bit)
+{
+	unsigned int i;
+	unsigned int mask = 0;
+	unsigned int tmp_mask;
+	unsigned long int flags;
+	enum cris_io_interface *owners;
+
+	(void)cris_io_interface_init();
+
+	DBG(printk("cris_io_interface_allocate_pins: if=%d port=%c start=%u stop=%u\n",
+		   ioif, port, start_bit, stop_bit));
+
+	if (!((start_bit <= stop_bit) &&
+	      ((((port == 'a') || (port == 'b')) && (stop_bit < 8)) ||
+	       ((port == 'g') && (stop_bit < 32))))) {
+		return -EINVAL;
+	}
+
+	mask = create_mask(stop_bit + 1);
+	tmp_mask = create_mask(start_bit);
+	mask &= ~tmp_mask;
+
+	DBG(printk("cris_io_interface_allocate_pins: port=%c start=%u stop=%u mask=0x%08x\n",
+		   port, start_bit, stop_bit, mask));
+
+	local_irq_save(flags);
+
+	switch (port) {
+	case 'a':
+		if ((gpio_pa_pins & mask) != mask) {
+			local_irq_restore(flags);
+			return -EBUSY;
+		}
+		owners = gpio_pa_owners;
+		gpio_pa_pins &= ~mask;
+		break;
+	case 'b':
+		if ((gpio_pb_pins & mask) != mask) {
+			local_irq_restore(flags);
+			return -EBUSY;
+		}
+		owners = gpio_pb_owners;
+		gpio_pb_pins &= ~mask;
+		break;
+	case 'g':
+		if (((gpio_in_pins & mask) != mask) ||
+		    ((gpio_out_pins & mask) != mask)) {
+			local_irq_restore(flags);
+			return -EBUSY;
+		}
+		owners = gpio_pg_owners;
+		gpio_in_pins &= ~mask;
+		gpio_out_pins &= ~mask;
+		break;
+	default:
+		local_irq_restore(flags);
+		return -EINVAL;
+	}
+
+	for (i = start_bit; i <= stop_bit; i++) {
+		owners[i] = ioif;
+	}
+	local_irq_restore(flags);
+
+	notify_watchers();
+	return 0;
+}
+
+
+/* port can be 'a', 'b' or 'g' */
+int cris_io_interface_free_pins(const enum cris_io_interface ioif,
+                                const char port,
+                                const unsigned start_bit,
+                                const unsigned stop_bit)
+{
+	unsigned int i;
+	unsigned int mask = 0;
+	unsigned int tmp_mask;
+	unsigned long int flags;
+	enum cris_io_interface *owners;
+
+	(void)cris_io_interface_init();
+
+	if (!((start_bit <= stop_bit) &&
+	      ((((port == 'a') || (port == 'b')) && (stop_bit < 8)) ||
+	       ((port == 'g') && (stop_bit < 32))))) {
+		return -EINVAL;
+	}
+
+	mask = create_mask(stop_bit + 1);
+	tmp_mask = create_mask(start_bit);
+	mask &= ~tmp_mask;
+
+	DBG(printk("cris_io_interface_free_pins: port=%c start=%u stop=%u mask=0x%08x\n",
+		   port, start_bit, stop_bit, mask));
+
+	local_irq_save(flags);
+
+	switch (port) {
+	case 'a':
+		if ((~gpio_pa_pins & mask) != mask) {
+			local_irq_restore(flags);
+			printk(KERN_CRIT "cris_io_interface_free_pins: Freeing free pins");
+		}
+		owners = gpio_pa_owners;
+		break;
+	case 'b':
+		if ((~gpio_pb_pins & mask) != mask) {
+			local_irq_restore(flags);
+			printk(KERN_CRIT "cris_io_interface_free_pins: Freeing free pins");
+		}
+		owners = gpio_pb_owners;
+		break;
+	case 'g':
+		if (((~gpio_in_pins & mask) != mask) ||
+		    ((~gpio_out_pins & mask) != mask)) {
+			local_irq_restore(flags);
+			printk(KERN_CRIT "cris_io_interface_free_pins: Freeing free pins");
+		}
+		owners = gpio_pg_owners;
+		break;
+	default:
+		owners = NULL; /* Cannot happen. Shut up, gcc! */
+	}
+
+	for (i = start_bit; i <= stop_bit; i++) {
+		if (owners[i] != ioif) {
+			printk(KERN_CRIT "cris_io_interface_free_pins: Freeing unowned pins");
+		}
+	}
+
+	/* All was ok, change data. */
+	switch (port) {
+	case 'a':
+		gpio_pa_pins |= mask;
+		break;
+	case 'b':
+		gpio_pb_pins |= mask;
+		break;
+	case 'g':
+		gpio_in_pins |= mask;
+		gpio_out_pins |= mask;
+		break;
+	}
+
+	for (i = start_bit; i <= stop_bit; i++) {
+		owners[i] = if_unclaimed;
+	}
+	local_irq_restore(flags);
+	notify_watchers();
+
+        return 0;
+}
+
+
+int cris_io_interface_register_watcher(void (*notify)(const unsigned int gpio_in_available,
+                                                      const unsigned int gpio_out_available,
+                                                      const unsigned char pa_available,
+                                                      const unsigned char pb_available))
+{
+	struct watcher *w;
+
+	(void)cris_io_interface_init();
+
+	if (NULL == notify) {
+		return -EINVAL;
+	}
+	w = kmalloc(sizeof(*w), GFP_KERNEL);
+	if (!w) {
+		return -ENOMEM;
+	}
+	w->notify = notify;
+	w->next = watchers;
+	watchers = w;
+
+	w->notify((const unsigned int)gpio_in_pins,
+		  (const unsigned int)gpio_out_pins,
+		  (const unsigned char)gpio_pa_pins,
+		  (const unsigned char)gpio_pb_pins);
+
+	return 0;
+}
+
+void cris_io_interface_delete_watcher(void (*notify)(const unsigned int gpio_in_available,
+						     const unsigned int gpio_out_available,
+                                                     const unsigned char pa_available,
+						     const unsigned char pb_available))
+{
+	struct watcher *w = watchers, *prev = NULL;
+
+	(void)cris_io_interface_init();
+
+	while ((NULL != w) && (w->notify != notify)){
+		prev = w;
+		w = w->next;
+	}
+	if (NULL != w) {
+		if (NULL != prev) {
+			prev->next = w->next;
+		} else {
+			watchers = w->next;
+		}
+		kfree(w);
+		return;
+	}
+	printk(KERN_WARNING "cris_io_interface_delete_watcher: Deleting unknown watcher 0x%p\n", notify);
+}
+
+
+static int cris_io_interface_init(void)
+{
+	static int first = 1;
+	int i;
+
+	if (!first) {
+		return 0;
+	}
+	first = 0;
+
+	for (i = 0; i<8; i++) {
+		gpio_pa_owners[i] = if_unclaimed;
+		gpio_pb_owners[i] = if_unclaimed;
+		gpio_pg_owners[i] = if_unclaimed;
+	}
+	for (; i<32; i++) {
+		gpio_pg_owners[i] = if_unclaimed;
+	}
+	return 0;
+}
+
+
+module_init(cris_io_interface_init);
+
+
+EXPORT_SYMBOL(cris_request_io_interface);
+EXPORT_SYMBOL(cris_free_io_interface);
+EXPORT_SYMBOL(cris_io_interface_allocate_pins);
+EXPORT_SYMBOL(cris_io_interface_free_pins);
+EXPORT_SYMBOL(cris_io_interface_register_watcher);
+EXPORT_SYMBOL(cris_io_interface_delete_watcher);