Re: [PATCH v2] driver for the "Fujitsu Tablet PC Buttons" device

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Robert,

On Wed, Nov 04, 2009 at 07:28:38PM +0100, Robert Gerlach wrote:
> This is a driver for the tablet buttons and the tablet mode switch of  
> many Fujitsu tablet PCs. The driver is based on reverse-engineering of  
> the Windows driver, I have no specification for this device. 
> 
> v2: small cleanup requested by GregKH

I wonder if this driver should go into drivers/platform/x86 with the rest of
ACPIish laptop drivers. Still, below some comments from input POV:

> +
> +#define REPEAT_RATE 16
> +#define REPEAT_DELAY 700
> +#define STICKY_TIMEOUT 1400	/* msec */
> +
> +#include <linux/kernel.h>

Defines are usually go after #includes

> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/version.h>
> +#include <linux/dmi.h>
> +#include <linux/bitops.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/acpi.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/interrupt.h>
> +#include <linux/input.h>
> +#include <linux/time.h>
> +#include <linux/timer.h>
> +#include <linux/delay.h>
> +#include <linux/jiffies.h>
> +
> +#define MODULENAME "fsc_btns"
> +
> +MODULE_AUTHOR("Robert Gerlach <khnz@users.sourceforge.net>");
> +MODULE_DESCRIPTION("Fujitsu Siemens tablet button driver");
> +MODULE_LICENSE("GPL");
> +MODULE_VERSION("2.1.0");
> +
> +static const struct acpi_device_id fscbtns_ids[] = {
> +	{ .id = "FUJ02BD" },
> +	{ .id = "FUJ02BF" },
> +	{ .id = "" }
> +};
> +MODULE_DEVICE_TABLE(acpi, fscbtns_ids);
> +
> +struct fscbtns_config {
> +	int invert_orientation_bit;
> +	unsigned int keymap[16];
> +};
> +
> +static struct fscbtns_config config_Lifebook_Tseries __initdata = {
> +	.invert_orientation_bit = 1,
> +	.keymap = {
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_SCROLLDOWN,
> +		KEY_SCROLLUP,
> +		KEY_DIRECTION,
> +		KEY_LEFTCTRL,
> +		KEY_BRIGHTNESSUP,
> +		KEY_BRIGHTNESSDOWN,
> +		KEY_BRIGHTNESS_ZERO,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_LEFTALT
> +	}
> +};
> +
> +static struct fscbtns_config config_Lifebook_U810 __initdata = {
> +	.invert_orientation_bit = 1,
> +	.keymap = {
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_PROG1,
> +		KEY_PROG2,
> +		KEY_DIRECTION,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_UP,
> +		KEY_DOWN,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_FN,
> +		KEY_SLEEP
> +	}
> +};
> +
> +static struct fscbtns_config config_Stylistic_Tseries __initdata = {
> +	.invert_orientation_bit = 0,
> +	.keymap = {
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_PRINT,
> +		KEY_BACKSPACE,
> +		KEY_SPACE,
> +		KEY_ENTER,
> +		KEY_BRIGHTNESSUP,
> +		KEY_BRIGHTNESSDOWN,
> +		KEY_DOWN,
> +		KEY_UP,
> +		KEY_SCROLLUP,
> +		KEY_SCROLLDOWN,
> +		KEY_FN
> +	}
> +};
> +
> +static struct fscbtns_config config_Stylistic_ST5xxx __initdata = {
> +	.invert_orientation_bit = 0,
> +	.keymap = {
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_RESERVED,
> +		KEY_MAIL,
> +		KEY_DIRECTION,
> +		KEY_ESC,
> +		KEY_ENTER,
> +		KEY_BRIGHTNESSUP,
> +		KEY_BRIGHTNESSDOWN,
> +		KEY_DOWN,
> +		KEY_UP,
> +		KEY_SCROLLUP,
> +		KEY_SCROLLDOWN,
> +		KEY_FN,
> +		KEY_LEFTALT
> +	}
> +};
> +
> +static const unsigned long modification_mask[BITS_TO_LONGS(KEY_MAX)] = {
> +		[BIT_WORD(KEY_LEFTSHIFT)]	= BIT_MASK(KEY_LEFTSHIFT),
> +		[BIT_WORD(KEY_RIGHTSHIFT)]	= BIT_MASK(KEY_RIGHTSHIFT),
> +		[BIT_WORD(KEY_LEFTCTRL)]	= BIT_MASK(KEY_LEFTCTRL),
> +		[BIT_WORD(KEY_RIGHTCTRL)]	= BIT_MASK(KEY_RIGHTCTRL),
> +		[BIT_WORD(KEY_LEFTALT)]		= BIT_MASK(KEY_LEFTALT),
> +		[BIT_WORD(KEY_RIGHTALT)]	= BIT_MASK(KEY_RIGHTALT),
> +		[BIT_WORD(KEY_LEFTMETA)]	= BIT_MASK(KEY_LEFTMETA),
> +		[BIT_WORD(KEY_RIGHTMETA)]	= BIT_MASK(KEY_RIGHTMETA),
> +		[BIT_WORD(KEY_COMPOSE)]		= BIT_MASK(KEY_COMPOSE),
> +		[BIT_WORD(KEY_LEFTALT)]		= BIT_MASK(KEY_LEFTALT),
> +		[BIT_WORD(KEY_FN)]		= BIT_MASK(KEY_FN)};
> +
> +static struct {						/* fscbtns_t */
> +	struct platform_device *pdev;
> +	struct input_dev *idev_b;		/* tablet buttons */
> +	struct input_dev *idev_s;		/* orientation switch */

Do we really need 2 separate devices?

> +	struct timer_list timer;		/* timer for sicky keys */
> +
> +	unsigned int interrupt;
> +	unsigned int address;
> +	struct fscbtns_config config;
> +
> +	int orientation;
> +} fscbtns;
> +
> +
> +/*** HELPER 
> *******************************************************************/
> +
> +static inline u8 fscbtns_ack(void)
> +{
> +	return inb(fscbtns.address+2);
> +}
> +
> +static inline u8 fscbtns_status(void)
> +{
> +	return inb(fscbtns.address+6);
> +}
> +
> +static inline u8 fscbtns_read_register(const u8 addr)
> +{
> +	outb(addr, fscbtns.address);
> +	return inb(fscbtns.address+4);
> +}
> +
> +static inline void fscbtns_use_config(struct fscbtns_config *config)
> +{
> +	memcpy(&fscbtns.config, config, sizeof(struct fscbtns_config));
> +}
> +
> +
> +/*** INPUT 
> ********************************************************************/
> +
> +static int __devinit input_fscbtns_setup_buttons(struct device *dev)
> +{
> +	struct input_dev *idev;
> +	int error;
> +	int x;
> +
> +	idev = input_allocate_device();
> +	if (!idev)
> +		return -ENOMEM;
> +
> +	idev->dev.parent = dev;
> +	idev->phys = "fsc/input0";
> +	idev->name = "fsc tablet buttons";
> +	idev->id.bustype = BUS_HOST;
> +	idev->id.vendor  = 0x1734;
> +	idev->id.product = 0x0001;
> +	idev->id.version = 0x0101;
> +
> +	idev->keycode = fscbtns.config.keymap;
> +	idev->keycodesize = sizeof(unsigned int);

sizeof(fscbtns.config.keymap[0]) is safer. Make it unsigned short btw.

> +	idev->keycodemax = sizeof(fscbtns.config.keymap) / idev->keycodesize;

ARRAY_SIZE();

> +
> +	set_bit(EV_REP, idev->evbit);
> +	set_bit(EV_KEY, idev->evbit);

__set_bit() - no need for locked operations here.

> +
> +	for (x = 0; x < idev->keycodemax; x++)
> +		if (((unsigned int *)idev->keycode)[x])
> +			set_bit(((unsigned int *)idev->keycode)[x],
> +					idev->keybit);

Just operate on fscbtns.config.keymap to avoid much casting.

> +
> +	set_bit(EV_MSC, idev->evbit);
> +	set_bit(MSC_SCAN, idev->mscbit);
> +
> +	error = input_register_device(idev);
> +	if (error) {
> +		input_free_device(idev);
> +		return error;
> +	}
> +
> +	idev->rep[REP_DELAY]  = REPEAT_DELAY;
> +	idev->rep[REP_PERIOD] = 1000 / REPEAT_RATE;
> +
> +	fscbtns.idev_b = idev;
> +	return 0;
> +}
> +
> +static int __devinit input_fscbtns_setup_switch(struct device *dev)
> +{
> +	struct input_dev *idev;
> +	int error;
> +
> +	idev = input_allocate_device();
> +	if (!idev)
> +		return -ENOMEM;
> +
> +	idev->dev.parent = dev;
> +	idev->phys = "fsc/input1";
> +	idev->name = "fsc tablet switch";
> +	idev->id.bustype = BUS_HOST;
> +	idev->id.vendor  = 0x1734;
> +	idev->id.product = 0x0002;
> +	idev->id.version = 0x0101;
> +
> +	set_bit(EV_SW, idev->evbit);
> +	set_bit(SW_TABLET_MODE, idev->swbit);
> +
> +	error = input_register_device(idev);
> +	if (error) {
> +		input_free_device(idev);
> +		return error;
> +	}
> +
> +	fscbtns.idev_s = idev;
> +	return 0;
> +}
> +
> +static void input_fscbtns_remove(void)
> +{
> +	if (fscbtns.idev_b)
> +		input_unregister_device(fscbtns.idev_b);
> +	if (fscbtns.idev_s)
> +		input_unregister_device(fscbtns.idev_s);
> +}
> +
> +static void fscbtns_report_orientation(void)
> +{
> +	int orientation = fscbtns_read_register(0xdd);
> +
> +	if (orientation & 0x02) {
> +		orientation ^= fscbtns.config.invert_orientation_bit;
> +		orientation &= 0x01;
> +
> +		if (orientation != fscbtns.orientation) {
> +			input_report_switch(fscbtns.idev_s, SW_TABLET_MODE,
> +					fscbtns.orientation = orientation);
> +			input_sync(fscbtns.idev_s);
> +		}
> +	}
> +}
> +
> +static void fscbtns_sticky_timeout(unsigned long keycode)
> +{
> +	input_report_key(fscbtns.idev_b, keycode, 0);
> +	input_sync(fscbtns.idev_b);
> +	fscbtns.timer.data = 0;
> +}
> +
> +static inline int fscbtns_sticky_report_key(unsigned int keycode, int 
> pressed)
> +{
> +	if (pressed) {
> +		del_timer(&fscbtns.timer);
> +		fscbtns.timer.expires = jiffies + (STICKY_TIMEOUT*HZ)/1000;
> +
> +		if (fscbtns.timer.data == keycode) {
> +			input_report_key(fscbtns.idev_b, keycode, 0);
> +			input_sync(fscbtns.idev_b);
> +		}
> +
> +		return 0;
> +	}
> +
> +	if ((fscbtns.timer.data) && (fscbtns.timer.data != keycode)) {
> +		input_report_key(fscbtns.idev_b, keycode, 0);
> +		input_sync(fscbtns.idev_b);
> +		input_report_key(fscbtns.idev_b, fscbtns.timer.data, 0);
> +		fscbtns.timer.data = 0;
> +		return 1;
> +	}
> +
> +	if (test_bit(keycode, modification_mask) &&
> +			(fscbtns.timer.expires > jiffies)) {
> +		fscbtns.timer.data = keycode;
> +		fscbtns.timer.function = fscbtns_sticky_timeout;
> +		add_timer(&fscbtns.timer);

I wonder if you should keep last keycode in the driver data and set up
the timer once and use mod_timer() here.

> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
> +static void fscbtns_report_key(unsigned int kmindex, int pressed)
> +{
> +	unsigned int keycode = fscbtns.config.keymap[kmindex];
> +	if (keycode == KEY_RESERVED)
> +		return;
> +
> +	if (pressed)
> +		input_event(fscbtns.idev_b, EV_MSC, MSC_SCAN, kmindex);
> +
> +	if (fscbtns_sticky_report_key(keycode, pressed))
> +		return;
> +
> +	input_report_key(fscbtns.idev_b, keycode, pressed);
> +	input_sync(fscbtns.idev_b);
> +}
> +
> +static void fscbtns_event(void)
> +{
> +	unsigned long keymask;
> +	unsigned long changed;
> +	static unsigned long prev_keymask;
> +
> +	fscbtns_report_orientation();
> +
> +	keymask  = fscbtns_read_register(0xde);
> +	keymask |= fscbtns_read_register(0xdf) << 8;
> +	keymask ^= 0xffff;
> +
> +	changed = keymask ^ prev_keymask;
> +
> +	if (changed) {
> +		int x = 0;
> +		int pressed = !!(keymask & changed);
> +
> +		/* save current state and filter not changed bits */
> +		prev_keymask = keymask;
> +
> +		/* get number of changed bit */
> +		while (!test_bit(x, &changed))
> +			x++;
> +
> +		fscbtns_report_key(x, pressed);
> +	}
> +}
> +
> +
> +/*** INTERRUPT 
> ****************************************************************/
> +
> +static void fscbtns_isr_do(struct work_struct *work)
> +{
> +	fscbtns_event();
> +	fscbtns_ack();
> +}
> +
> +static DECLARE_WORK(isr_wq, fscbtns_isr_do);
> +
> +static irqreturn_t fscbtns_isr(int irq, void *dev_id)
> +{
> +	if (!(fscbtns_status() & 0x01))
> +		return IRQ_NONE;
> +
> +	schedule_work(&isr_wq);
> +	return IRQ_HANDLED;
> +}
> +
> +
> +/*** DEVICE 
> *******************************************************************/
> +
> +static int fscbtns_busywait(void)
> +{
> +	int timeout_counter = 100;
> +
> +	while (fscbtns_status() & 0x02 && --timeout_counter)
> +		msleep(10);
> +
> +	return !timeout_counter;
> +}
> +
> +static void fscbtns_reset(void)
> +{
> +	fscbtns_ack();
> +	if (fscbtns_busywait())
> +		printk(KERN_WARNING MODULENAME ": timeout, reset needed!\n");
> +}
> +
> +static int __devinit fscbtns_probe(struct platform_device *pdev)
> +{
> +	int error;
> +
> +	error = input_fscbtns_setup_buttons(&pdev->dev);
> +	if (error)
> +		goto err_input;
> +
> +	error = input_fscbtns_setup_switch(&pdev->dev);
> +	if (error)
> +		goto err_input;
> +
> +	if (!request_region(fscbtns.address, 8, MODULENAME)) {
> +		printk(KERN_ERR MODULENAME ": region 0x%04x busy\n",
> +				fscbtns.address);
> +		error = -EBUSY;
> +		goto err_input;
> +	}
> +
> +	fscbtns_reset();
> +
> +	fscbtns_report_orientation();
> +	input_sync(fscbtns.idev_b);
> +
> +	error = request_irq(fscbtns.interrupt, fscbtns_isr,
> +			IRQF_SHARED, MODULENAME, fscbtns_isr);
> +	if (error) {
> +		printk(KERN_ERR MODULENAME ": unable to get irq %d\n",
> +				fscbtns.interrupt);
> +		goto err_io;
> +	}
> +
> +	return 0;
> +
> +err_io:
> +	release_region(fscbtns.address, 8);
> +err_input:
> +	input_fscbtns_remove();
> +	return error;
> +}
> +
> +static int __devexit fscbtns_remove(struct platform_device *pdev)
> +{
> +	free_irq(fscbtns.interrupt, fscbtns_isr);
> +	release_region(fscbtns.address, 8);
> +	input_fscbtns_remove();
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM
> +static int fscbtns_resume(struct platform_device *pdev)
> +{
> +	fscbtns_reset();
> +#if 0 /* because Xorg Bug #9623 */
> +	fscbtns_report_orientation();
> +#endif
> +	return 0;
> +}
> +#endif
> +
> +static struct platform_driver fscbtns_platform_driver = {
> +	.driver		= {
> +		.name	= MODULENAME,
> +		.owner	= THIS_MODULE,
> +	},
> +	.probe		= fscbtns_probe,
> +	.remove		= __devexit_p(fscbtns_remove),
> +#ifdef CONFIG_PM
> +	.resume		= fscbtns_resume,
> +#endif
> +};
> +
> +
> +/*** ACPI 
> *********************************************************************/
> +
> +static acpi_status fscbtns_walk_resources(struct acpi_resource *res, void 
> *data)
> +{
> +	switch (res->type) {
> +	case ACPI_RESOURCE_TYPE_IRQ:
> +		fscbtns.interrupt = res->data.irq.interrupts[0];
> +		return AE_OK;
> +
> +	case ACPI_RESOURCE_TYPE_IO:
> +		fscbtns.address = res->data.io.minimum;
> +		return AE_OK;
> +
> +	case ACPI_RESOURCE_TYPE_END_TAG:
> +		if (fscbtns.interrupt && fscbtns.address)
> +			return AE_OK;
> +		else
> +			return AE_NOT_FOUND;
> +
> +	default:
> +		return AE_ERROR;
> +	}
> +}
> +
> +static int acpi_fscbtns_add(struct acpi_device *adev)
> +{
> +	acpi_status status;
> +
> +	if (!adev)
> +		return -EINVAL;
> +
> +	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
> +			fscbtns_walk_resources, NULL);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	return 0;
> +}
> +
> +static struct acpi_driver acpi_fscbtns_driver = {
> +	.name  = MODULENAME,
> +	.class = "hotkey",
> +	.ids   = fscbtns_ids,
> +	.ops   = {
> +		.add    = acpi_fscbtns_add
> +	}
> +};
> +
> +
> +/*** DMI 
> **********************************************************************/
> +
> +static int __init fscbtns_dmi_matched(const struct dmi_system_id *dmi)
> +{
> +	printk(KERN_INFO MODULENAME ": found: %s\n", dmi->ident);
> +	fscbtns_use_config(dmi->driver_data);
> +	return 1;
> +}
> +
> +static struct dmi_system_id dmi_ids[] __initdata = {
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Fujitsu Siemens P/T Series",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK")
> +		},
> +		.driver_data = &config_Lifebook_Tseries
> +	},
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Fujitsu Lifebook T Series",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "LifeBook T")
> +		},
> +		.driver_data = &config_Lifebook_Tseries
> +	},
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Fujitsu Siemens Stylistic T Series",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Stylistic T")
> +		},
> +		.driver_data = &config_Stylistic_Tseries
> +	},
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Fujitsu LifeBook U810",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "LifeBook U810")
> +		},
> +		.driver_data = &config_Lifebook_U810
> +	},
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Fujitsu Siemens Stylistic ST5xxx Series",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "STYLISTIC ST5")
> +		},
> +		.driver_data = &config_Stylistic_ST5xxx
> +	},
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Fujitsu Siemens Stylistic ST5xxx Series",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Stylistic ST5")
> +		},
> +		.driver_data = &config_Stylistic_ST5xxx
> +	},
> +	{
> +		.callback = fscbtns_dmi_matched,
> +		.ident = "Unknown (using defaults)",
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, ""),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "")
> +		},
> +		.driver_data = &config_Lifebook_Tseries
> +	},
> +	{ NULL }
> +};
> +
> +
> +/*** MODULE 
> *******************************************************************/
> +
> +static int __init fscbtns_module_init(void)
> +{
> +	int error;
> +
> +	dmi_check_system(dmi_ids);
> +
> +	error = acpi_bus_register_driver(&acpi_fscbtns_driver);
> +	if (ACPI_FAILURE(error))
> +		return -EINVAL;
> +
> +	if (!fscbtns.interrupt || !fscbtns.address)

You need to unregister acpi driver here.

> +		return -ENODEV;
> +
> +	init_timer(&fscbtns.timer);
> +
> +	error = platform_driver_register(&fscbtns_platform_driver);
> +	if (error)
> +		goto err;
> +
> +	fscbtns.pdev = platform_device_alloc(MODULENAME, -1);
> +	if (!fscbtns.pdev) {
> +		error = -ENOMEM;
> +		goto err_pdrv;
> +	}
> +
> +	error = platform_device_add(fscbtns.pdev);

This should be platform_device_register().

> +	if (error)
> +		goto err_pdev;
> +
> +	return 0;
> +
> +err_pdev:
> +	platform_device_put(fscbtns.pdev);
> +err_pdrv:
> +	platform_driver_unregister(&fscbtns_platform_driver);
> +err:
> +	acpi_bus_unregister_driver(&acpi_fscbtns_driver);
> +
> +	del_timer_sync(&fscbtns.timer);
> +
> +	return error;
> +}
> +
> +static void __exit fscbtns_module_exit(void)
> +{
> +	platform_device_unregister(fscbtns.pdev);
> +	platform_driver_unregister(&fscbtns_platform_driver);
> +	acpi_bus_unregister_driver(&acpi_fscbtns_driver);
> +
> +	del_timer_sync(&fscbtns.timer);

Isn't this too late?

> +}
> +
> +module_init(fscbtns_module_init);
> +module_exit(fscbtns_module_exit);

Thanks.

-- 
Dmitry