base/SOURCES/0557-udev-builtin-keyboard-add-support-for-EVDEV_ABS_.patch

From e6682abae36dcfe8a093686a3bd67b3568157c35 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Thu, 19 Mar 2015 14:19:58 +1000
Subject: [PATCH] udev: builtin-keyboard: add support for EVDEV_ABS_*

Parse properties in the form
EVDEV_ABS_00="<min>:<max>:<res>:<fuzz>:<flat>"

and apply them to the kernel device. Future processes that open that device
will see the updated EV_ABS range.

This is particularly useful for touchpads that don't provide a resolution in
the kernel driver but can be fixed up through hwdb entries (e.g. bcm5974).

All values in the property are optional, e.g. a string of "::45" is valid to
set the resolution to 45.

The order intentionally orders resolution before fuzz and flat despite it
being the last element in the absinfo struct. The use-case for setting
fuzz/flat is almost non-existent, resolution is probably the most common case
we'll need.

To avoid multiple hwdb invocations for the same device, replace the
hwdb "keyboard:" prefix with "evdev:" and drop the separate 60-keyboard.rules
file. The new 60-evdev.rules is called for all event nodes
anyway, we don't need a separate rules file and second callout to the hwdb
builtin.

(cherry picked from commit 51c0c2869845a058268d54c3111d55d0dd485704)

Changes to the upstream commit:
- 60-keyboard.rules is left in place, the 60-keyboard.hwdb is left
  unmodified. This avoids any potential breakage from user-installed hwdb
  files that are triggered by that rule.

Conflicts:
	hwdb/60-keyboard.hwdb
	rules/60-keyboard.rules

Resolves: #1500119
---
 Makefile.am                      |  2 +
 hwdb/60-evdev.hwdb               | 37 +++++++++++++++++
 rules/60-evdev.rules             | 14 +++++++
 src/udev/udev-builtin-keyboard.c | 86 ++++++++++++++++++++++++++++++++++++++--
 4 files changed, 135 insertions(+), 4 deletions(-)
 create mode 100644 hwdb/60-evdev.hwdb
 create mode 100644 rules/60-evdev.rules

diff --git a/Makefile.am b/Makefile.am
index a1ebf5cb0..13c93f485 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3499,6 +3499,7 @@ dist_udevrules_DATA += \
 	rules/42-usb-hid-pm.rules \
 	rules/50-udev-default.rules \
 	rules/60-drm.rules \
+	rules/60-evdev.rules \
 	rules/60-keyboard.rules \
 	rules/60-persistent-storage-tape.rules \
 	rules/60-persistent-serial.rules \
@@ -3702,6 +3703,7 @@ dist_udevhwdb_DATA = \
 	hwdb/20-acpi-vendor.hwdb \
 	hwdb/20-OUI.hwdb \
 	hwdb/20-net-ifname.hwdb \
+	hwdb/60-evdev.hwdb \
 	hwdb/60-keyboard.hwdb \
 	hwdb/70-mouse.hwdb \
 	hwdb/70-touchpad.hwdb
diff --git a/hwdb/60-evdev.hwdb b/hwdb/60-evdev.hwdb
new file mode 100644
index 000000000..ad2d09e72
--- /dev/null
+++ b/hwdb/60-evdev.hwdb
@@ -0,0 +1,37 @@
+# This file is part of systemd.
+#
+# The lookup keys are composed in:
+#   60-evdev.rules
+#
+# Note: The format of the "evdev:" prefix match key is a
+# contract between the rules file and the hardware data, it might
+# change in later revisions to support more or better matches, it
+# is not necessarily expected to be a stable ABI.
+#
+# Match string formats:
+# evdev:<modalias>
+# evdev:name:<device name>:dmi:<dmi string>
+#
+# To add local entries, create a new file
+#   /etc/udev/hwdb.d/61-evdev-local.hwdb
+# and add your rules there. To load the new rules execute (as root):
+#   udevadm hwdb --update
+#   udevadm trigger /dev/input/eventXX
+# where /dev/input/eventXX is the device in question. If in
+# doubt, simply use /dev/input/event* to reload all input rules.
+#
+# If your changes are generally applicable, open a bug report on
+#   http://bugs.freedesktop.org/enter_bug.cgi?product=systemd
+# and include your new rules, a description of the device, and the
+# output of
+#   udevadm info /dev/input/eventXX
+# (or /dev/input/event*).
+#
+# Allowed properties are:
+#    EVDEV_ABS_<axis>=<min>:<max>:<res>:<fuzz>:<flat>
+#
+# where <axis> is the hexadecimal EV_ABS code as listed in linux/input.h
+# and min, max, res, fuzz, flat are the decimal values to the respective
+# fields of the struct input_absinfo as listed in linux/input.h.
+# If a field is missing the field will be left as-is. Not all fields need to
+# be present. e.g. ::45 sets the resolution to 45 units/mm.
diff --git a/rules/60-evdev.rules b/rules/60-evdev.rules
new file mode 100644
index 000000000..67308ad23
--- /dev/null
+++ b/rules/60-evdev.rules
@@ -0,0 +1,14 @@
+# do not edit this file, it will be overwritten on update
+
+ACTION=="remove", GOTO="evdev_end"
+KERNEL!="event*", GOTO="evdev_end"
+
+# skip later rules when we find something for this input device
+IMPORT{builtin}="hwdb --subsystem=input --lookup-prefix=evdev:", \
+  RUN{builtin}+="keyboard", GOTO="evdev_end"
+
+# device matching the input device name and the machine's DMI data
+KERNELS=="input*", IMPORT{builtin}="hwdb 'evdev:name:$attr{name}:$attr{[dmi/id]modalias}'", \
+  RUN{builtin}+="keyboard", GOTO="evdev_end"
+
+LABEL="evdev_end"
diff --git a/src/udev/udev-builtin-keyboard.c b/src/udev/udev-builtin-keyboard.c
index 86f4018ef..eaa21abf6 100644
--- a/src/udev/udev-builtin-keyboard.c
+++ b/src/udev/udev-builtin-keyboard.c
@@ -99,6 +99,69 @@ static void map_keycode(int fd, const char *devnode, int scancode, const char *k
                 log_error_errno(errno, "Error calling EVIOCSKEYCODE on device node '%s' (scan code 0x%x, key code %d): %m", devnode, map.scan, map.key);
 }
 
+static inline char* parse_token(const char *current, int32_t *val_out) {
+        char *next;
+        int32_t val;
+
+        if (!current)
+                return NULL;
+
+        val = strtol(current, &next, 0);
+        if (*next && *next != ':')
+                return NULL;
+
+        if (next != current)
+                *val_out = val;
+
+        if (*next)
+                next++;
+
+        return next;
+}
+
+static void override_abs(int fd, const char *devnode,
+                         unsigned evcode, const char *value) {
+        struct input_absinfo absinfo;
+        int rc;
+        char *next;
+
+        rc = ioctl(fd, EVIOCGABS(evcode), &absinfo);
+        if (rc < 0) {
+                log_error_errno(errno, "Error, unable to EVIOCGABS device '%s'",
+                                devnode);
+                return;
+        }
+
+        next = parse_token(value, &absinfo.minimum);
+        next = parse_token(next, &absinfo.maximum);
+        next = parse_token(next, &absinfo.resolution);
+        next = parse_token(next, &absinfo.fuzz);
+        next = parse_token(next, &absinfo.flat);
+        if (!next) {
+                log_error("Error, unable to parse EV_ABS override '%s' for '%s'\n",
+                          value, devnode);
+                return;
+        }
+
+        log_debug("keyboard: override %x with %d/%d/%d/%d/%d", evcode,
+                  absinfo.minimum, absinfo.maximum, absinfo.resolution,
+                  absinfo.fuzz, absinfo.flat);
+        rc = ioctl(fd, EVIOCSABS(evcode), &absinfo);
+        if (rc < 0)
+                log_error_errno(errno, "Error, unable to update device '%s'",
+                                devnode);
+}
+
+static int open_device(const char *devnode) {
+        int fd;
+
+        fd = open(devnode, O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+        if (fd < 0)
+                log_error_errno(errno, "Error, opening device '%s': %m", devnode);
+
+        return fd < 0 ? -errno : fd;
+}
+
 static int builtin_keyboard(struct udev_device *dev, int argc, char *argv[], bool test) {
         struct udev_list_entry *entry;
         unsigned release[1024];
@@ -143,14 +206,29 @@ static int builtin_keyboard(struct udev_device *dev, int argc, char *argv[], boo
                         }
 
                         if (fd == -1) {
-                                fd = open(node, O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
-                                if (fd < 0) {
-                                        log_error_errno(errno, "Error, opening device '%s': %m", node);
+                                fd = open_device(node);
+                                if (fd < 0)
                                         return EXIT_FAILURE;
-                                }
                         }
 
                         map_keycode(fd, node, scancode, keycode);
+                } else if (startswith(key, "EVDEV_ABS_")) {
+                        unsigned evcode;
+
+                        /* EVDEV_ABS_<EV_ABS code>=<min>:<max>:<res>:<fuzz>:<flat> */
+                        evcode = strtoul(key + 10, &endptr, 16);
+                        if (endptr[0] != '\0') {
+                                log_error("Error, unable to parse EV_ABS code from '%s'", key);
+                                continue;
+                        }
+
+                        if (fd == -1) {
+                                fd = open_device(node);
+                                if (fd < 0)
+                                        return EXIT_FAILURE;
+                        }
+
+                        override_abs(fd, node, evcode, udev_list_entry_get_value(entry));
                 }
         }