[PATCH 032/112] ACPI: thinkpad-acpi: document keymap gotcha's (v2)

Len Brown
2008-02-07T09:35:59Z

From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>

Publish the requirements for keymap changes. This is a documentation
change, only.

Currently, people look at the thinkpad-acpi default keymaps, and think:
"modifying this is a trivial thing, it can't break systems, and there are
keys defined for foo and bar, but the driver has them as KEY_RESERVED.
Must have been an oversight, let me change it."

And since they never get to see the bug reports, because they are not
really a part of the Linux ThinkPad users community (linux-thinkpad
mailinglist, thinkwiki wiki, thinkpad forums) and laptop users are slow
to complain to distros about any breakages...

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/misc/thinkpad_acpi.c | 68 ++++++++++++++++++++++++++++++++++++++---
1 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index cf56647..7b1080f 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -954,26 +954,67 @@ static struct attribute *hotkey_mask_attributes[] __initdata = {

static int __init hotkey_init(struct ibm_init_struct *iibm)
{
-
+ /* Requirements for changing the default keymaps:
+ *
+ * 1. Many of the keys are mapped to KEY_RESERVED for very
+ * good reasons. Do not change them unless you have deep
+ * knowledge on the IBM and Lenovo ThinkPad firmware for
+ * the various ThinkPad models. The driver behaves
+ * differently for KEY_RESERVED: such keys have their
+ * hot key mask *unset* in mask_recommended, and also
+ * in the initial hot key mask programmed into the
+ * firmware at driver load time, which means the firm-
+ * ware may react very differently if you change them to
+ * something else;
+ *
+ * 2. You must be subscribed to the linux-thinkpad and
+ * ibm-acpi-devel mailing lists, and you should read the
+ * list archives since 2007 if you want to change the
+ * keymaps. This requirement exists so that you will
+ * know the past history of problems with the thinkpad-
+ * acpi driver keymaps, and also that you will be
+ * listening to any bug reports;
+ *
+ * 3. Do not send thinkpad-acpi specific patches directly to
+ * for merging, *ever*. Send them to the linux-acpi
+ * mailinglist for comments. Merging is to be done only
+ * through acpi-test and the ACPI maintainer.
+ *
+ * If the above is too much to ask, don't change the keymap.
+ * Ask the thinkpad-acpi maintainer to do it, instead.
+ */
static u16 ibm_keycode_map[] __initdata = {
/* Scan Codes 0x00 to 0x0B: ACPI HKEY FN+F1..F12 */
KEY_FN_F1, KEY_FN_F2, KEY_COFFEE, KEY_SLEEP,
KEY_WLAN, KEY_FN_F6, KEY_SWITCHVIDEOMODE, KEY_FN_F8,
KEY_FN_F9, KEY_FN_F10, KEY_FN_F11, KEY_SUSPEND,
- /* Scan codes 0x0C to 0x0F: Other ACPI HKEY hot keys */
+
+ /* Scan codes 0x0C to 0x1F: Other ACPI HKEY hot keys */
KEY_UNKNOWN, /* 0x0C: FN+BACKSPACE */
KEY_UNKNOWN, /* 0x0D: FN+INSERT */
KEY_UNKNOWN, /* 0x0E: FN+DELETE */
+
+ /* brightness: firmware always reacts to them, unless
+ * X.org did some tricks in the radeon BIOS scratch
+ * registers of *some* models */
KEY_RESERVED, /* 0x0F: FN+HOME (brightness up) */
- /* Scan codes 0x10 to 0x1F: Extended ACPI HKEY hot keys */
KEY_RESERVED, /* 0x10: FN+END (brightness down) */
+
+ /* Thinklight: firmware always react to it */
KEY_RESERVED, /* 0x11: FN+PGUP (thinklight toggle) */
+
KEY_UNKNOWN, /* 0x12: FN+PGDOWN */
KEY_ZOOM, /* 0x13: FN+SPACE (zoom) */
+
+ /* Volume: firmware always react to it and reprograms
+ * the built-in *extra* mixer. Never map it to control
+ * another mixer by default. */
KEY_RESERVED, /* 0x14: VOLUME UP */
KEY_RESERVED, /* 0x15: VOLUME DOWN */
KEY_RESERVED, /* 0x16: MUTE */
+
KEY_VENDOR, /* 0x17: Thinkpad/AccessIBM/Lenovo */
+
/* (assignments unknown, please report if found) */
KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
@@ -983,20 +1024,37 @@ static int __init hotkey_init(struct ibm_init_struct *iibm)
KEY_FN_F1, KEY_COFFEE, KEY_BATTERY, KEY_SLEEP,
KEY_WLAN, KEY_FN_F6, KEY_SWITCHVIDEOMODE, KEY_FN_F8,
KEY_FN_F9, KEY_FN_F10, KEY_FN_F11, KEY_SUSPEND,
- /* Scan codes 0x0C to 0x0F: Other ACPI HKEY hot keys */
+
+ /* Scan codes 0x0C to 0x1F: Other ACPI HKEY hot keys */
KEY_UNKNOWN, /* 0x0C: FN+BACKSPACE */
KEY_UNKNOWN, /* 0x0D: FN+INSERT */
KEY_UNKNOWN, /* 0x0E: FN+DELETE */
+
KEY_RESERVED, /* 0x0F: FN+HOME (brightness up) */
- /* Scan codes 0x10 to 0x1F: Extended ACPI HKEY hot keys */
KEY_RESERVED, /* 0x10: FN+END (brightness down) */
+
KEY_RESERVED, /* 0x11: FN+PGUP (thinklight toggle) */
+
KEY_UNKNOWN, /* 0x12: FN+PGDOWN */
KEY_ZOOM, /* 0x13: FN+SPACE (zoom) */
+
+ /* Volume: z60/z61, T60 (BIOS version?): firmware always
+ * react to it and reprograms the built-in *extra* mixer.
+ * Never map it to control another mixer by default.
+ *
+ * T60?, T61, R60?, R61: firmware and EC tries to send
+ * these over the regular keyboard, so these are no-ops,
+ * but there are still weird bugs re. MUTE, so do not
+ * change unless you get test reports from all Lenovo
+ * models. May cause the BIOS to interfere with the
+ * HDA mixer.
+ */
KEY_RESERVED, /* 0x14: VOLUME UP */
KEY_RESERVED, /* 0x15: VOLUME DOWN */
KEY_RESERVED, /* 0x16: MUTE */
+
KEY_VENDOR, /* 0x17: Thinkpad/AccessIBM/Lenovo */
+
/* (assignments unknown, please report if found) */
KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN, KEY_UNKNOWN,
--
1.5.4.23.gef5b9