Re: [PATCH] Fujitsu application panel driver

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 23 Oct 2007 12:55:55 -0700
Stephen Hemminger <shemminger@linux-foundation.org> wrote:

> This driver supports the application buttons on some Fujitsu Lifebook
> laptops. It is based on the earlier apanel driver done by Jochen
> Eisenger, but with many changes.  The original driver used ioctl's and
> a separate user space program (see http://apanel.sourceforge.net). This
> driver hooks into the input subsystem so that the normal keys act as
> expected without a daemon. In addition to buttons, the Mail Led is
> handled via LEDs class device.
> 
> The driver now supports redefinable keymaps and no longer has to
> have a DMI table for all Fujitsu laptops.
> 
> I thought about mixing this driver should be integrated into the Fujitsu laptop
> extras driver that handles backlight, but rejected the idea because
> it wasn't clear if all the Fujitsu laptops supported both.
> 
> ...
>
> +
> +/* Magic constants in BIOS that tell about buttons */
> +enum apanel_devid {
> +	APANEL_DEV_NONE	  = 0,
> +	APANEL_DEV_APPBTN = 1,
> +	APANEL_DEV_CDBTN  = 2,
> +	APANEL_DEV_LCD	  = 3,
> +	APANEL_DEV_LED	  = 4,
> +	APANEL_DEV_MAX,
> +};

APANEL_DEV_MAX == 5.

> +enum apanel_chip {
> +	CHIP_NONE    = 0,
> +	CHIP_OZ992C  = 1,
> +	CHIP_OZ163T  = 2,
> +	CHIP_OZ711M3 = 4,
> +};
> +
> +/* Result of BIOS snooping/probing -- what features are supported */
> +static enum apanel_chip device_chip[APANEL_DEV_MAX];
> +
> +/* names for APANEL_XXX */
> +static const char *device_names[APANEL_DEV_MAX] __initdata = {

We just wasted sizeof(char *)?

> +	[APANEL_DEV_APPBTN] = "Application Buttons",
> +	[APANEL_DEV_LCD]    = "LCD",
> +	[APANEL_DEV_LED]    = "LED",
> +	[APANEL_DEV_CDBTN]  = "CD Buttons",
> +};
> +
> +
> +/* Poll for key changes
> + *
> + * Read Application keys via SMI
> + *  A (0x4), B (0x8), Internet (0x2), Email (0x1).
> + *
> + * CD keys:
> + * Forward (0x100), Rewind (0x200), Stop (0x400), Pause (0x800)
> + */
> +static void apanel_poll(struct input_polled_dev *ipdev)
> +{
> +	struct apanel *ap = ipdev->private;
> +	struct input_dev *idev = ipdev->input;
> +	u8 cmd = device_chip[APANEL_DEV_APPBTN] == CHIP_OZ992C ? 0 : 8;
> +	s32 data;
> +	int i;
> +
> +	data = i2c_smbus_read_word_data(&ap->client, cmd);
> +	if (data < 0)
> +		return;	/* ignore errors (due to ACPI??) */
> +
> +	/* write back to clear latch */
> +	i2c_smbus_write_word_data(&ap->client, cmd, 0);
> +
> +	if (!data)
> +		return;
> +
> +	dev_dbg(&ipdev->input->dev, APANEL ": data %#x\n", data);
> +	for (i = 0; i < ipdev->input->keycodemax; i++)
> +		if (1ul << i & data)

You made me google for the c precedence table.

> +			report_key(idev, ap->keymap[i]);
> +}
>
> ...
>