Hi Dmitry,
On Mon, Aug 16, 2010 at 03:26:37PM +0400, Dmitry Eremin-Solenikov wrote:
> 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;
I wonder if instead of indices you should make them serio * pointers -
it will save a few cycles at the expense of about 14 bytes in the
structure.
> + unsigned escape:1;
bool please.
> +};
> +
> +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);
Maybe pull all commands into ps2mult_ctrl_bytes[] array and use single
need_escape = memchr(ps2mult_ctrl_bytes, data, sizeof(ps2mult_ctrl_bytes));
?
> +
> + 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;
I thought you were going to use SERIO_I8042?
> + serio->write = ps2mult_serio_write;
> + serio->parent = psm->serio;
You also need to define serio->stop() method that would mark appropriate
port as being dead and ensure that ps2mult_interrupt() does not try to use
ports that are being destroyed. Otherwise, during tear-down, when
children are being disconnected first, there potential to get interrupt
at a bad time.
> +
> + 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;
Meaningless since you free the structure couple of lines below.
> +
> + 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;
> + }
I'd move call to serio_open() here, just in case.
> +
> + 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);
Why do you need this 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) {
Incorrect indentation.
> + 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);
If there are only 2 ports why don't you do:
psm->current_in_port = psm->ports[PSM_MOUSE_IDX].serio;
?
> + 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
>
Still pondering your other patch...
Thanks.
--
Dmitry
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