[PATCH 4/4] psmouse: dynamic protocol switching via sysfs

From: Dmitry Torokhov
Date: Tue Mar 22 2005 - 02:30:30 EST

===================================================================

Input: psmouse - export protocol as a sysfs per-device attribute.

Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>


drivers/input/mouse/psmouse-base.c | 291 ++++++++++++++++++++++++++++++-------
drivers/input/mouse/psmouse.h | 1
drivers/input/serio/serio.c | 44 +++++
include/linux/serio.h | 6
4 files changed, 290 insertions(+), 52 deletions(-)

Index: dtor/drivers/input/serio/serio.c
===================================================================
--- dtor.orig/drivers/input/serio/serio.c
+++ dtor/drivers/input/serio/serio.c
@@ -43,6 +43,7 @@ MODULE_LICENSE("GPL");
EXPORT_SYMBOL(serio_interrupt);
EXPORT_SYMBOL(__serio_register_port);
EXPORT_SYMBOL(serio_unregister_port);
+EXPORT_SYMBOL(serio_unregister_child_port);
EXPORT_SYMBOL(__serio_unregister_port_delayed);
EXPORT_SYMBOL(__serio_register_driver);
EXPORT_SYMBOL(serio_unregister_driver);
@@ -90,12 +91,19 @@ static void serio_bind_driver(struct ser
down_write(&serio_bus.subsys.rwsem);

if (serio_match_port(drv->id_table, serio)) {
+ /* make sure parent is not about to change */
+ if (serio->parent)
+ down(&serio->parent->drv_sem);
+
serio->dev.driver = &drv->driver;
if (drv->connect(serio, drv)) {
serio->dev.driver = NULL;
goto out;
}
device_bind_driver(&serio->dev);
+
+ if (serio->parent)
+ up(&serio->parent->drv_sem);
}
out:
up_write(&serio_bus.subsys.rwsem);
@@ -150,12 +158,12 @@ static void serio_queue_event(void *obje
spin_lock_irqsave(&serio_event_lock, flags);

/*
- * Scan event list for the other events for the same serio port,
+ * Scan event list for the other events for the same serio port,
* starting with the most recent one. If event is the same we
* do not need add new one. If event is of different type we
* need to add this event and should not look further because
* we need to preseve sequence of distinct events.
- */
+ */
list_for_each_entry_reverse(event, &serio_event_list, node) {
if (event->object == object) {
if (event->type == event_type)
@@ -614,6 +622,19 @@ void serio_unregister_port(struct serio
}

/*
+ * Safely unregisters child port if one is present.
+ */
+void serio_unregister_child_port(struct serio *serio)
+{
+ down(&serio_sem);
+ if (serio->child) {
+ serio_disconnect_port(serio->child);
+ serio_destroy_port(serio->child);
+ }
+ up(&serio_sem);
+}
+
+/*
* Submits register request to kseriod for subsequent execution.
* Can be used when it is not obvious whether the serio_sem is
* taken or not and when delayed execution is feasible.
@@ -669,8 +690,18 @@ static int serio_driver_probe(struct dev
{
struct serio *serio = to_serio_port(dev);
struct serio_driver *drv = to_serio_driver(dev->driver);
+ int result;
+
+ /* make sure parent is not about to change */
+ if (serio->parent)
+ down(&serio->parent->drv_sem);
+
+ result = drv->connect(serio, drv);
+
+ if (serio->parent)
+ up(&serio->parent->drv_sem);

- return drv->connect(serio, drv);
+ return result;
}

static int serio_driver_remove(struct device *dev)
@@ -678,7 +709,14 @@ static int serio_driver_remove(struct de
struct serio *serio = to_serio_port(dev);
struct serio_driver *drv = to_serio_driver(dev->driver);

+ if (serio->parent)
+ down(&serio->parent->drv_sem);
+
drv->disconnect(serio);
+
+ if (serio->parent)
+ up(&serio->parent->drv_sem);
+
return 0;
}

Index: dtor/drivers/input/mouse/psmouse.h
===================================================================
--- dtor.orig/drivers/input/mouse/psmouse.h
+++ dtor/drivers/input/mouse/psmouse.h
@@ -78,6 +78,7 @@ enum psmouse_type {
PSMOUSE_SYNAPTICS,
PSMOUSE_ALPS,
PSMOUSE_LIFEBOOK,
+ PSMOUSE_AUTO /* This one should always be last */
};

int psmouse_sliced_command(struct psmouse *psmouse, unsigned char command);
Index: dtor/include/linux/serio.h
===================================================================
--- dtor.orig/include/linux/serio.h
+++ dtor/include/linux/serio.h
@@ -83,6 +83,7 @@ static inline void serio_register_port(s
}

void serio_unregister_port(struct serio *serio);
+void serio_unregister_child_port(struct serio *serio);
void __serio_unregister_port_delayed(struct serio *serio, struct module *owner);
static inline void serio_unregister_port_delayed(struct serio *serio)
{
@@ -153,6 +154,11 @@ static inline int serio_pin_driver(struc
return down_interruptible(&serio->drv_sem);
}

+static inline void serio_pin_driver_uninterruptible(struct serio *serio)
+{
+ down(&serio->drv_sem);
+}
+
static inline void serio_unpin_driver(struct serio *serio)
{
up(&serio->drv_sem);
Index: dtor/drivers/input/mouse/psmouse-base.c
===================================================================
--- dtor.orig/drivers/input/mouse/psmouse-base.c
+++ dtor/drivers/input/mouse/psmouse-base.c
@@ -32,15 +32,14 @@ MODULE_AUTHOR("Vojtech Pavlik <vojtech@s
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

-static unsigned int psmouse_max_proto = -1U;
+static unsigned int psmouse_max_proto = PSMOUSE_AUTO;
static int psmouse_set_maxproto(const char *val, struct kernel_param *kp);
static int psmouse_get_maxproto(char *buffer, struct kernel_param *kp);
-static char *psmouse_proto_abbrev[] = { NULL, "bare", NULL, NULL, NULL, "imps", "exps", NULL, NULL, "lifebook" };
#define param_check_proto_abbrev(name, p) __param_check(name, p, unsigned int)
#define param_set_proto_abbrev psmouse_set_maxproto
#define param_get_proto_abbrev psmouse_get_maxproto
module_param_named(proto, psmouse_max_proto, proto_abbrev, 0644);
-MODULE_PARM_DESC(proto, "Highest protocol extension to probe (bare, imps, exps, lifebook, any). Useful for KVM switches.");
+MODULE_PARM_DESC(proto, "Highest protocol extension to probe (bare, imps, exps, any). Useful for KVM switches.");

static unsigned int psmouse_resolution = 200;
module_param_named(resolution, psmouse_resolution, uint, 0644);
@@ -58,6 +57,7 @@ static unsigned int psmouse_resetafter;
module_param_named(resetafter, psmouse_resetafter, uint, 0644);
MODULE_PARM_DESC(resetafter, "Reset device after so many bad packets (0 = never).");

+PSMOUSE_DEFINE_ATTR(protocol);
PSMOUSE_DEFINE_ATTR(rate);
PSMOUSE_DEFINE_ATTR(resolution);
PSMOUSE_DEFINE_ATTR(resetafter);
@@ -68,7 +68,14 @@ __obsolete_setup("psmouse_smartscroll=")
__obsolete_setup("psmouse_resetafter=");
__obsolete_setup("psmouse_rate=");

-static char *psmouse_protocols[] = { "None", "PS/2", "PS2++", "ThinkPS/2", "GenPS/2", "ImPS/2", "ImExPS/2", "SynPS/2", "AlpsPS/2", "LBPS/2" };
+struct psmouse_protocol {
+ enum psmouse_type type;
+ char *name;
+ char *alias;
+ int maxproto;
+ int (*detect)(struct psmouse *, int);
+ int (*init)(struct psmouse *);
+};

/*
* psmouse_process_byte() analyzes the PS/2 data stream and reports
@@ -408,12 +415,15 @@ static int thinking_detect(struct psmous
*/
static int ps2bare_detect(struct psmouse *psmouse, int set_properties)
{
- if (!psmouse->vendor) psmouse->vendor = "Generic";
- if (!psmouse->name) psmouse->name = "Mouse";
+ if (set_properties) {
+ if (!psmouse->vendor) psmouse->vendor = "Generic";
+ if (!psmouse->name) psmouse->name = "Mouse";
+ }

return 0;
}

+
/*
* psmouse_extensions() probes for any extensions to the basic PS/2 protocol
* the mouse may have.
@@ -428,9 +438,7 @@ static int psmouse_extensions(struct psm
* We always check for lifebook because it does not disturb mouse
* (it only checks DMI information).
*/
- if (lifebook_detect(psmouse, set_properties) == 0 ||
- max_proto == PSMOUSE_LIFEBOOK) {
-
+ if (lifebook_detect(psmouse, set_properties) == 0) {
if (max_proto > PSMOUSE_IMEX) {
if (!set_properties || lifebook_init(psmouse) == 0)
return PSMOUSE_LIFEBOOK;
@@ -520,6 +528,103 @@ static int psmouse_extensions(struct psm
return PSMOUSE_PS2;
}

+static struct psmouse_protocol psmouse_protocols[] = {
+ {
+ .type = PSMOUSE_PS2,
+ .name = "PS/2",
+ .alias = "bare",
+ .maxproto = 1,
+ .detect = ps2bare_detect,
+ },
+ {
+ .type = PSMOUSE_PS2PP,
+ .name = "PS2++",
+ .alias = "logitech",
+ .detect = ps2pp_init,
+ },
+ {
+ .type = PSMOUSE_THINKPS,
+ .name = "ThinkPS/2",
+ .alias = "thinkps",
+ .detect = thinking_detect,
+ },
+ {
+ .type = PSMOUSE_GENPS,
+ .name = "GenPS/2",
+ .alias = "genius",
+ .detect = genius_detect,
+ },
+ {
+ .type = PSMOUSE_IMPS,
+ .name = "ImPS/2",
+ .alias = "imps",
+ .maxproto = 1,
+ .detect = intellimouse_detect,
+ },
+ {
+ .type = PSMOUSE_IMEX,
+ .name = "ImExPS/2",
+ .alias = "exps",
+ .maxproto = 1,
+ .detect = im_explorer_detect,
+ },
+ {
+ .type = PSMOUSE_SYNAPTICS,
+ .name = "SynPS/2",
+ .alias = "synaptics",
+ .detect = synaptics_detect,
+ .init = synaptics_init,
+ },
+ {
+ .type = PSMOUSE_ALPS,
+ .name = "AlpsPS/2",
+ .alias = "alps",
+ .detect = alps_detect,
+ .init = alps_init,
+ },
+ {
+ .type = PSMOUSE_LIFEBOOK,
+ .name = "LBPS/2",
+ .alias = "lifebook",
+ .init = lifebook_init,
+ },
+ {
+ .type = PSMOUSE_AUTO,
+ .name = "auto",
+ .alias = "any",
+ .maxproto = 1,
+ },
+};
+
+static struct psmouse_protocol *psmouse_protocol_by_type(enum psmouse_type type)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++)
+ if (psmouse_protocols[i].type == type)
+ return &psmouse_protocols[i];
+
+ WARN_ON(1);
+ return &psmouse_protocols[0];
+}
+
+static struct psmouse_protocol *psmouse_protocol_by_name(const char *name, size_t len)
+{
+ struct psmouse_protocol *p;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(psmouse_protocols); i++) {
+ p = &psmouse_protocols[i];
+
+ if ((strlen(p->name) == len && !strncmp(p->name, name, len)) ||
+ (strlen(p->alias) == len && !strncmp(p->alias, name, len)))
+ return &psmouse_protocols[i];
+ }
+
+ return NULL;
+}
+
+
/*
* psmouse_probe() probes for a PS/2 mouse.
*/
@@ -669,6 +774,7 @@ static void psmouse_disconnect(struct se
{
struct psmouse *psmouse, *parent;

+ device_remove_file(&serio->dev, &psmouse_attr_protocol);
device_remove_file(&serio->dev, &psmouse_attr_rate);
device_remove_file(&serio->dev, &psmouse_attr_resolution);
device_remove_file(&serio->dev, &psmouse_attr_resetafter);
@@ -693,6 +799,49 @@ static void psmouse_disconnect(struct se
kfree(psmouse);
}

+static int psmouse_switch_protocol(struct psmouse *psmouse, struct psmouse_protocol *proto)
+{
+ memset(&psmouse->dev, 0, sizeof(struct input_dev));
+
+ init_input_dev(&psmouse->dev);
+
+ psmouse->dev.private = psmouse;
+ psmouse->dev.dev = &psmouse->ps2dev.serio->dev;
+
+ psmouse->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_REL);
+ psmouse->dev.keybit[LONG(BTN_MOUSE)] = BIT(BTN_LEFT) | BIT(BTN_MIDDLE) | BIT(BTN_RIGHT);
+ psmouse->dev.relbit[0] = BIT(REL_X) | BIT(REL_Y);
+
+ psmouse->set_rate = psmouse_set_rate;
+ psmouse->set_resolution = psmouse_set_resolution;
+ psmouse->protocol_handler = psmouse_process_byte;
+ psmouse->pktsize = 3;
+
+ if (proto && (proto->detect || proto->init)) {
+ if (proto->detect && proto->detect(psmouse, 1) < 0)
+ return -1;
+
+ if (proto->init && proto->init(psmouse) < 0)
+ return -1;
+
+ psmouse->type = proto->type;
+ }
+ else
+ psmouse->type = psmouse_extensions(psmouse, psmouse_max_proto, 1);
+
+ sprintf(psmouse->devname, "%s %s %s",
+ psmouse_protocol_by_type(psmouse->type)->name, psmouse->vendor, psmouse->name);
+
+ psmouse->dev.name = psmouse->devname;
+ psmouse->dev.phys = psmouse->phys;
+ psmouse->dev.id.bustype = BUS_I8042;
+ psmouse->dev.id.vendor = 0x0002;
+ psmouse->dev.id.product = psmouse->type;
+ psmouse->dev.id.version = psmouse->model;
+
+ return 0;
+}
+
/*
* psmouse_connect() is a callback from the serio module when
* an unhandled serio port is found.
@@ -720,11 +869,7 @@ static int psmouse_connect(struct serio

ps2_init(&psmouse->ps2dev, serio);
sprintf(psmouse->phys, "%s/input0", serio->phys);
- psmouse->dev.evbit[0] = BIT(EV_KEY) | BIT(EV_REL);
- psmouse->dev.keybit[LONG(BTN_MOUSE)] = BIT(BTN_LEFT) | BIT(BTN_MIDDLE) | BIT(BTN_RIGHT);
- psmouse->dev.relbit[0] = BIT(REL_X) | BIT(REL_Y);
- psmouse->dev.private = psmouse;
- psmouse->dev.dev = &serio->dev;
+
psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);

serio_set_drvdata(serio, psmouse);
@@ -748,25 +893,10 @@ static int psmouse_connect(struct serio
psmouse->resolution = psmouse_resolution;
psmouse->resetafter = psmouse_resetafter;
psmouse->smartscroll = psmouse_smartscroll;
- psmouse->set_rate = psmouse_set_rate;
- psmouse->set_resolution = psmouse_set_resolution;
- psmouse->protocol_handler = psmouse_process_byte;
- psmouse->pktsize = 3;

- psmouse->type = psmouse_extensions(psmouse, psmouse_max_proto, 1);
-
- sprintf(psmouse->devname, "%s %s %s",
- psmouse_protocols[psmouse->type], psmouse->vendor, psmouse->name);
-
- psmouse->dev.name = psmouse->devname;
- psmouse->dev.phys = psmouse->phys;
- psmouse->dev.id.bustype = BUS_I8042;
- psmouse->dev.id.vendor = 0x0002;
- psmouse->dev.id.product = psmouse->type;
- psmouse->dev.id.version = psmouse->model;
+ psmouse_switch_protocol(psmouse, NULL);

input_register_device(&psmouse->dev);
-
printk(KERN_INFO "input: %s on %s\n", psmouse->devname, serio->phys);

psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
@@ -776,6 +906,7 @@ static int psmouse_connect(struct serio
if (parent && parent->pt_activate)
parent->pt_activate(parent);

+ device_create_file(&serio->dev, &psmouse_attr_protocol);
device_create_file(&serio->dev, &psmouse_attr_rate);
device_create_file(&serio->dev, &psmouse_attr_resolution);
device_create_file(&serio->dev, &psmouse_attr_resetafter);
@@ -914,11 +1045,14 @@ ssize_t psmouse_attr_set_helper(struct d
parent = serio_get_drvdata(serio->parent);
psmouse_deactivate(parent);
}
+
psmouse_deactivate(psmouse);

retval = handler(psmouse, buf, count);

- psmouse_activate(psmouse);
+ if (retval != -ENODEV)
+ psmouse_activate(psmouse);
+
if (parent)
psmouse_activate(parent);

@@ -927,6 +1061,73 @@ out:
return retval;
}

+static ssize_t psmouse_attr_show_protocol(struct psmouse *psmouse, char *buf)
+{
+ return sprintf(buf, "%s\n", psmouse_protocol_by_type(psmouse->type)->name);
+}
+
+static ssize_t psmouse_attr_set_protocol(struct psmouse *psmouse, const char *buf, size_t count)
+{
+ struct serio *serio = psmouse->ps2dev.serio;
+ struct psmouse *parent = NULL;
+ struct psmouse_protocol *proto;
+ int retry = 0;
+
+ if (!(proto = psmouse_protocol_by_name(buf, count)))
+ return -EINVAL;
+
+ if (psmouse->type == proto->type)
+ return count;
+
+ while (serio->child) {
+ if (++retry > 3) {
+ printk(KERN_WARNING "psmouse: failed to destroy child port, protocol change aborted.\n");
+ return -EIO;
+ }
+
+ serio_unpin_driver(serio);
+ serio_unregister_child_port(serio);
+ serio_pin_driver_uninterruptible(serio);
+
+ if (serio->drv != &psmouse_drv)
+ return -ENODEV;
+
+ if (psmouse->type == proto->type)
+ return count; /* switched by other thread */
+ }
+
+ if (serio->parent && serio->id.type == SERIO_PS_PSTHRU) {
+ parent = serio_get_drvdata(serio->parent);
+ if (parent->pt_deactivate)
+ parent->pt_deactivate(parent);
+ }
+
+ if (psmouse->disconnect)
+ psmouse->disconnect(psmouse);
+
+ psmouse_set_state(psmouse, PSMOUSE_IGNORE);
+ input_unregister_device(&psmouse->dev);
+
+ psmouse_set_state(psmouse, PSMOUSE_INITIALIZING);
+
+ if (psmouse_switch_protocol(psmouse, proto) < 0) {
+ psmouse_reset(psmouse);
+ /* default to PSMOUSE_PS2 */
+ psmouse_switch_protocol(psmouse, &psmouse_protocols[0]);
+ }
+
+ psmouse_initialize(psmouse);
+ psmouse_set_state(psmouse, PSMOUSE_CMD_MODE);
+
+ input_register_device(&psmouse->dev);
+ printk(KERN_INFO "input: %s on %s\n", psmouse->devname, serio->phys);
+
+ if (parent && parent->pt_activate)
+ parent->pt_activate(parent);
+
+ return count;
+}
+
static ssize_t psmouse_attr_show_rate(struct psmouse *psmouse, char *buf)
{
return sprintf(buf, "%d\n", psmouse->rate);
@@ -983,34 +1184,26 @@ static ssize_t psmouse_attr_set_resetaft

static int psmouse_set_maxproto(const char *val, struct kernel_param *kp)
{
- int i;
+ struct psmouse_protocol *proto;

if (!val)
return -EINVAL;

- if (!strncmp(val, "any", 3)) {
- *((unsigned int *)kp->arg) = -1U;
- return 0;
- }
+ proto = psmouse_protocol_by_name(val, strlen(val));

- for (i = 0; i < ARRAY_SIZE(psmouse_proto_abbrev); i++) {
- if (!psmouse_proto_abbrev[i])
- continue;
-
- if (!strncmp(val, psmouse_proto_abbrev[i], strlen(psmouse_proto_abbrev[i]))) {
- *((unsigned int *)kp->arg) = i;
- return 0;
- }
- }
+ if (!proto || !proto->maxproto)
+ return -EINVAL;

- return -EINVAL; \
+ *((unsigned int *)kp->arg) = proto->type;
+
+ return 0; \
}

static int psmouse_get_maxproto(char *buffer, struct kernel_param *kp)
{
- return sprintf(buffer, "%s\n",
- psmouse_max_proto < ARRAY_SIZE(psmouse_proto_abbrev) ?
- psmouse_proto_abbrev[psmouse_max_proto] : "any");
+ int type = *((unsigned int *)kp->arg);
+
+ return sprintf(buffer, "%s\n", psmouse_protocol_by_type(type)->name);
}

static int __init psmouse_init(void)
-
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