PS2Mult is a simple serial protocol used for multiplexing several PS/2 streams
into one serial data stream. It's used e.g. on TQM85xx serie of boards.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
---
drivers/input/serio/Kconfig | 8 ++
drivers/input/serio/Makefile | 1 +
drivers/input/serio/ps2mult.c | 265 +++++++++++++++++++++++++++++++++++++++++
include/linux/serio.h | 2 +
4 files changed, 276 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/serio/ps2mult.c
diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index 3bfe8fa..63f4658 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -226,4 +226,12 @@ config SERIO_AMS_DELTA
To compile this driver as a module, choose M here;
the module will be called ams_delta_serio.
+config SERIO_PS2MULT
+ tristate "TQC PS/2 multiplexer"
+ help
+ Say Y here if you have the PS/2 line multiplexer like present on TQC boads
+
+ To compile this driver as a module, choose M here: the
+ module will be called ps2mult.
+
endif
diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 84c80bf..26714c5 100644
--- a/drivers/input/serio/Makefile
+++ b/drivers/input/serio/Makefile
@@ -24,3 +24,4 @@ obj-$(CONFIG_SERIO_RAW) += serio_raw.o
obj-$(CONFIG_SERIO_AMS_DELTA) += ams_delta_serio.o
obj-$(CONFIG_SERIO_XILINX_XPS_PS2) += xilinx_ps2.o
obj-$(CONFIG_SERIO_ALTERA_PS2) += altera_ps2.o
+obj-$(CONFIG_SERIO_PS2MULT) += ps2mult.o
diff --git a/drivers/input/serio/ps2mult.c b/drivers/input/serio/ps2mult.c
new file mode 100644
index 0000000..e9b7951
--- /dev/null
+++ b/drivers/input/serio/ps2mult.c
@@ -0,0 +1,265 @@
+/*
+ * TQC PS/2 Multiplexer driver
+ *
+ * Copyright (C) 2010 Dmitry Eremin-Solenikov
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/serio.h>
+
+MODULE_AUTHOR("Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>");
+MODULE_DESCRIPTION("TQC PS/2 Multiplexer driver");
+MODULE_LICENSE("GPL");
+
+#define PS2MULT_KB_SELECTOR 0xA0
+#define PS2MULT_MS_SELECTOR 0xA1
+#define PS2MULT_ESCAPE 0x7D
+#define PS2MULT_BSYNC 0x7E
+#define PS2MULT_SESSION_START 0x55
+#define PS2MULT_SESSION_END 0x56
+
+struct ps2mult_port {
+ struct serio *serio;
+ unsigned char sel;
+ unsigned char port;
+};
+
+#define PS2MULT_NUM_PORTS 2
+
+struct ps2mult {
+ struct serio *serio;
+ struct ps2mult_port ports[PS2MULT_NUM_PORTS];
+
+ spinlock_t lock;
+ unsigned char cur_out_port;
+ unsigned char cur_in_port;
+ unsigned escape:1;
+};
+
+static unsigned char ps2mult_selectors[PS2MULT_NUM_PORTS] = {
+ PS2MULT_KB_SELECTOR, PS2MULT_MS_SELECTOR,
+};
+
+static struct serio_device_id ps2mult_serio_ids[] = {
+ {
+ .type = SERIO_RS232,
+ .proto = SERIO_PS2MULT,
+ .id = SERIO_ANY,
+ .extra = SERIO_ANY,
+ },
+ { 0 }
+};
+
+MODULE_DEVICE_TABLE(serio, ps2mult_serio_ids);
+
+static int ps2mult_serio_write(struct serio *serio, unsigned char data)
+{
+ struct ps2mult *psm = serio_get_drvdata(serio->parent);
+ struct ps2mult_port *psmp = serio->port_data;
+ bool need_escape;
+ unsigned long flags;
+
+ spin_lock_irqsave(&psm->lock, flags);
+ if (psm->cur_out_port != psmp->port) {
+ psm->serio->write(psm->serio, psmp->sel);
+ psm->cur_out_port = psmp->port;
+ dev_dbg(&serio->dev, "switched to sel %02x\n", psmp->sel);
+ }
+
+ need_escape = data == PS2MULT_ESCAPE
+ || data == PS2MULT_BSYNC
+ || data == PS2MULT_SESSION_START
+ || data == PS2MULT_SESSION_END
+ || memchr(ps2mult_selectors, data, PS2MULT_NUM_PORTS);
+
+ dev_dbg(&serio->dev, "write: %s%02x\n",
+ need_escape ? "ESC " : "", data);
+
+ if (need_escape)
+ psm->serio->write(psm->serio, PS2MULT_ESCAPE);
+ psm->serio->write(psm->serio, data);
+
+ spin_unlock_irqrestore(&psm->lock, flags);
+
+ return 0;
+}
+
+static int ps2mult_create_port(struct ps2mult *psm, int i)
+{
+ struct serio *serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!serio)
+ return -ENOMEM;
+
+ strlcpy(serio->name, "TQC PS/2 Multiplexer", sizeof(serio->name));
+ snprintf(serio->phys, sizeof(serio->phys),
+ "%s/port%d", psm->serio->phys, i);
+ serio->id.type = SERIO_PS2MULT_T;
+ serio->write = ps2mult_serio_write;
+ serio->parent = psm->serio;
+
+ serio->port_data = &psm->ports[i];
+
+ psm->ports[i].serio = serio;
+ psm->ports[i].port = i;
+ psm->ports[i].sel = ps2mult_selectors[i];
+
+ serio_register_port(serio);
+ dev_info(&serio->dev, "%s port at %s\n", serio->name, psm->serio->phys);
+
+ return 0;
+}
+
+static int ps2mult_reconnect(struct serio *serio)
+{
+ struct ps2mult *psm = serio_get_drvdata(serio);
+
+ serio->write(serio, PS2MULT_SESSION_END);
+ serio->write(serio, PS2MULT_SESSION_START);
+ psm->cur_out_port = 0;
+ serio->write(serio, psm->ports[psm->cur_out_port].sel);
+
+ return 0;
+}
+
+static void ps2mult_disconnect(struct serio *serio)
+{
+ struct ps2mult *psm = serio_get_drvdata(serio);
+ int i;
+
+ serio->write(serio, PS2MULT_SESSION_END);
+
+ for (i = 0; i < PS2MULT_NUM_PORTS; i++)
+ psm->ports[i].serio = NULL;
+
+ serio_close(serio);
+ serio_set_drvdata(serio, NULL);
+
+ kfree(psm);
+}
+
+static int ps2mult_connect(struct serio *serio, struct serio_driver *drv)
+{
+ struct ps2mult *psm;
+ int i;
+ int rc;
+
+ if (!serio->write)
+ return -EINVAL;
+
+ psm = kzalloc(sizeof(*psm), GFP_KERNEL);
+ if (!psm)
+ return -ENOMEM;
+
+ spin_lock_init(&psm->lock);
+ psm->serio = serio;
+
+ serio_set_drvdata(serio, psm);
+ serio_open(serio, drv);
+
+ for (i = 0; i < PS2MULT_NUM_PORTS; i++) {
+ rc = ps2mult_create_port(psm, i);
+ if (rc)
+ goto err_out;
+ }
+
+ rc = ps2mult_reconnect(serio);
+ if (rc)
+ goto err_out;
+
+ return 0;
+
+err_out:
+ ps2mult_disconnect(serio);
+
+ return rc;
+}
+
+static void ps2mult_selector(struct ps2mult *psm, unsigned char data)
+{
+ int i;
+
+ dev_dbg(&psm->serio->dev, "Received selector %02x\n", data);
+
+ spin_lock(&psm->lock);
+
+ for (i = 0; i < PS2MULT_NUM_PORTS; i++)
+ if (psm->ports[i].sel == data) {
+ psm->cur_in_port = i;
+ break;
+ }
+
+ spin_unlock(&psm->lock);
+}
+
+static irqreturn_t ps2mult_interrupt(struct serio *serio, unsigned char data,
+ unsigned int flags)
+{
+ struct ps2mult *psm = serio_get_drvdata(serio);
+
+ dev_dbg(&serio->dev, "Received %02x flags %02x\n", data, flags);
+ if (psm->escape) {
+ serio_interrupt(psm->ports[psm->cur_in_port].serio,
+ data, flags);
+ psm->escape = 0;
+ } else
+ switch (data) {
+ case PS2MULT_ESCAPE:
+ dev_dbg(&serio->dev, "ESCAPE\n");
+ psm->escape = 1;
+ break;
+ case PS2MULT_BSYNC:
+ dev_dbg(&serio->dev, "BSYNC\n");
+ psm->cur_in_port = psm->cur_out_port;
+ break;
+ case PS2MULT_SESSION_START:
+ dev_dbg(&serio->dev, "SS\n");
+ break;
+ case PS2MULT_SESSION_END:
+ dev_dbg(&serio->dev, "SE\n");
+ break;
+ case PS2MULT_KB_SELECTOR:
+ dev_dbg(&serio->dev, "KB\n");
+ ps2mult_selector(psm, data);
+ break;
+ case PS2MULT_MS_SELECTOR:
+ dev_dbg(&serio->dev, "MS\n");
+ ps2mult_selector(psm, data);
+ break;
+ default:
+ serio_interrupt(psm->ports[psm->cur_in_port].serio,
+ data, flags);
+ }
+ return IRQ_HANDLED;
+}
+
+static struct serio_driver ps2mult_drv = {
+ .driver = {
+ .name = "ps2mult",
+ },
+ .description = "TQC PS/2 Multiplexer driver",
+ .id_table = ps2mult_serio_ids,
+ .interrupt = ps2mult_interrupt,
+ .connect = ps2mult_connect,
+ .disconnect = ps2mult_disconnect,
+ .reconnect = ps2mult_reconnect,
+};
+
+static int __init ps2mult_init(void)
+{
+ return serio_register_driver(&ps2mult_drv);
+}
+
+static void __exit ps2mult_exit(void)
+{
+ serio_unregister_driver(&ps2mult_drv);
+}
+
+module_init(ps2mult_init);
+module_exit(ps2mult_exit);
diff --git a/include/linux/serio.h b/include/linux/serio.h
index 861a72a..7257e6c 100644
--- a/include/linux/serio.h
+++ b/include/linux/serio.h
@@ -156,6 +156,7 @@ static inline void serio_continue_rx(struct serio *serio)
#define SERIO_HIL_MLC 0x03
#define SERIO_PS_PSTHRU 0x05
#define SERIO_8042_XL 0x06
+#define SERIO_PS2MULT_T 0x07
/*
* Serio protocols
@@ -200,5 +201,6 @@ static inline void serio_continue_rx(struct serio *serio)
#define SERIO_W8001 0x39
#define SERIO_DYNAPRO 0x3a
#define SERIO_HAMPSHIRE 0x3b
+#define SERIO_PS2MULT 0x3c
#endif
--
1.7.1
--
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