Hi Pau.
Some nitpick comments - looks good overall.
On Sat, May 17, 2008 at 02:44:14PM +0200, Pau Oliva Fora wrote:
> From: Pau Oliva Fora <pau@xxxxxxxxxx>
>
> The patch below adds support for HTC Shift UMPC touchscreen.
>
> Signed-off-by: Pau Oliva Fora <pau@xxxxxxxxxx>
>
> ---
>
> Patch against linux-2.6.25.4, should apply clean on other versions too.
>
>
> diff -uprN linux-2.6.25.4/drivers/input/touchscreen/htcpen.c
> linux/drivers/input/touchscreen/htcpen.c
> --- linux-2.6.25.4/drivers/input/touchscreen/htcpen.c 1970-01-01
> 01:00:00.000000000 +0100
> +++ linux/drivers/input/touchscreen/htcpen.c 2008-05-17
> 13:48:57.000000000 +0200
> @@ -0,0 +1,148 @@
> +/*
> + * HTC Shift touchscreen driver
> + *
> + * Copyright (C) 2008 Pau Oliva Fora <pof@xxxxxxxxxx>
> + *
> + * Thanks to:
> + * Heikki Linnakangas - Penmount LPC touchscreen driver
> + * Wacom / Ping Cheng - Help on linuxwacom-devel
> + * Esteve Espuna - Ideas, tips, moral support :)
> + *
> + * Changelog:
> + * 29980517 v0.5 - code cleanup
> + * 29980517 v0.4 - initialization works (thanks esteve!)
> + * 20080514 v0.3 - works best with TouchKit egalax xorg driver
> + * 20080511 v0.2 - little hacks to make it more usable
> + * 20080510 v0.1 - works with evtouch driver
> + * 20080428 first non-working attempt
Drop changelog - we do not keep them in-kernel.
Here we rely on git.
You can add it to your commit message if your prefer to
have it saved.
> + */
> +
> +/*
> + * 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/errno.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/input.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/init.h>
> +#include <linux/irq.h>
> +
> +#define DRIVER_VERSION "v0.5"
> +#define DRIVER_DESC "HTC Shift touchscreen driver"
> +
> +MODULE_AUTHOR("Pau Oliva Fora <pau@xxxxxxxxxx>");
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_LICENSE("GPL");
> +
> +#define HTCPEN_PORT0 0x068
> +#define HTCPEN_PORT1 0x06c
> +#define HTCPEN_PORT2 0x0250
> +#define HTCPEN_PORT3 0x0251
The use of the four ports would be nice to be documented
> +#define HTCPEN_IRQ 3
> +
> +static int inverse_y;
> +module_param(inverse_y, bool, 0644);
> +MODULE_PARM_DESC(inverse_y, "If set Y axe is inversed.");
> +
> +struct input_dev *htcpen_dev;
> +
> +static void poll_htcpen(void)
> +{
> +
> + unsigned short x, y, xy;
General comment.
In kernel we usually do not have an empty line following the
opening '{'
> + unsigned short touch;
> +
> + /* 0=press ; 1=release */
> + outb_p(0xb, HTCPEN_PORT2);
> + touch = inb_p(HTCPEN_PORT3);
> + if (touch)
> + touch = 0;
> + else
> + touch = 1;
> +
> + input_report_key(htcpen_dev, BTN_TOUCH, touch);
> +
> + /* only update x/y when screen is being touched */
> + if (touch) {
> + outb_p(3, HTCPEN_PORT2);
What is the semantic of 3 here.
Add a comment or a DEFINE
> + x = inb_p(HTCPEN_PORT3);
> +
> + outb_p(5, HTCPEN_PORT2);
Same here.
> + y = inb_p(HTCPEN_PORT3);
> +
> + outb_p(0xc, HTCPEN_PORT2);
Same here.
> + xy = inb_p(HTCPEN_PORT3);
> +
> + x = 8*255-((x*8)+((xy>>4)&0xf));
> + y = (y*8)+(xy&0xf);
> + if (inverse_y)
> + y = 8*255-y;
These calculations needs spaces and comments.
> +
> + input_report_abs(htcpen_dev, ABS_X, x);
> + input_report_abs(htcpen_dev, ABS_Y, y);
> + }
> +
> + input_sync(htcpen_dev);
> +
> + inb_p(HTCPEN_PORT0);
> +}
> +
> +static irqreturn_t htcpen_interrupt(int irq, void *handle)
> +{
> + poll_htcpen();
> + return IRQ_HANDLED;
> +}
> +
> +
> +static int __init htcpen_init(void)
> +{
> +
> + printk(KERN_INFO "htcpen: module inserted\n");
> +
> + inb_p(HTCPEN_PORT0);
> +
> + htcpen_dev = input_allocate_device();
> + if (!htcpen_dev) {
> + printk(KERN_ERR "htcpen: can't allocate device\n");
> + return -ENOMEM;
> + }
> +
> + if (request_irq(HTCPEN_IRQ, htcpen_interrupt, 0, "htcpen", NULL)) {
> + printk(KERN_ERR "htcpen: irq busy\n");
> + return -EBUSY;
> + }
I would asusme you are missing a: input_unregister_device(htcpen_dev);?
> +
> + htcpen_dev->name = "HTC Pen TouchScreen";
> + htcpen_dev->id.bustype = BUS_ISA;
> + htcpen_dev->id.vendor = 0;
> + htcpen_dev->id.product = 0;
> + htcpen_dev->id.version = 0;
> +
> + input_set_abs_params(htcpen_dev, ABS_X, 0, 255*8, 0, 0);
> + input_set_abs_params(htcpen_dev, ABS_Y, 0, 255*8, 0, 0);
Again a 'magic' calculation
> +
> + htcpen_dev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
> + htcpen_dev->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y);
> + htcpen_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
> +
> + input_register_device(htcpen_dev);
> +
> + outb_p(0xa2, HTCPEN_PORT1);
> +
> + return 0;
> +}
> +
> +static void __exit htcpen_exit(void)
> +{
> + input_unregister_device(htcpen_dev);
> + free_irq(HTCPEN_IRQ, NULL);
> + printk(KERN_INFO "htcpen: module removed\n");
> +}
> +
> +module_init(htcpen_init);
> +module_exit(htcpen_exit);
Sam
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