Sorry about the noise - device tree mailing has changed.
I haven't heard back from anyone after making the last modifications
a week ago. If it's all good with you Rob, please ack it so that
Dmitry can pick it up on his side.
Thanks,
Mathieu.
>From 37318cb3c6339747f4e96e09f07f732a395a5ae1 Mon Sep 17 00:00:00 2001
From: "Mathieu J. Poirier" <mathieu.poirier@xxxxxxxxxx>
Date: Wed, 10 Jul 2013 09:53:35 -0600
Subject: [RESEND PATCH v5] Input: sysrq - DT binding for key sequence
Adding a simple device tree binding for the specification of key sequences.
Definition of the keys found in the sequence are located in
'include/uapi/linux/input.h'.
For the sysrq driver, holding the sequence of keys down for a specific amount of time
will reset the system.
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
changes for v5:
- Corrected error in binding definition.
- Using helper macro to fetch the key sequence.
- Removing white space.
---
.../devicetree/bindings/input/input-reset.txt | 34 ++++++++++++++++++++
drivers/tty/sysrq.c | 37 ++++++++++++++++++++++
2 files changed, 71 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/input-reset.txt
diff --git a/Documentation/devicetree/bindings/input/input-reset.txt b/Documentation/devicetree/bindings/input/input-reset.txt
new file mode 100644
index 0000000..c69390c
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/input-reset.txt
@@ -0,0 +1,34 @@
+Input: sysrq reset sequence
+
+A simple binding to represent a set of keys as described in
+include/uapi/linux/input.h. This is to communicate a
+sequence of keys to the sysrq driver. Upon holding the keys
+for a specified amount of time (if specified) the system is
+sync'ed and reset.
+
+Key sequences are global to the system but all the keys in a
+set must be coming from the same input device.
+
+The /chosen node should contain a 'linux,sysrq-reset-seq' child
+node to define a set of keys.
+
+Required property:
+sysrq-reset-seq: array of keycodes
+
+Optional property:
+timeout-ms: duration keys must be pressed together in milliseconds
+before generating a sysrq
+
+Example:
+
+ chosen {
+ linux,sysrq-reset-seq {
+ keyset = <0x03
+ 0x04
+ 0x0a>;
+ timeout-ms = <3000>;
+ };
+ };
+
+Would represent KEY_2, KEY_3 and KEY_9.
+
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index b51c154..ed8f00f 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -44,6 +44,7 @@
#include <linux/uaccess.h>
#include <linux/moduleparam.h>
#include <linux/jiffies.h>
+#include <linux/of.h>
#include <asm/ptrace.h>
#include <asm/irq_regs.h>
@@ -671,6 +672,34 @@ static void sysrq_detect_reset_sequence(struct sysrq_state *state,
}
}
+static void sysrq_of_get_keyreset_config(void)
+{
+ u32 key;
+ struct device_node *np;
+ struct property *prop;
+ const __be32 *p;
+
+ np = of_find_node_by_path("/chosen/linux,sysrq-reset-seq");
+ if (!np) {
+ pr_debug("No sysrq node found");
+ return;
+ }
+
+ /* reset in case a __weak definition was present */
+ sysrq_reset_seq_len = 0;
+
+ of_property_for_each_u32(np, "keyset", prop, p, key) {
+ if ((key == KEY_RESERVED || key > KEY_MAX) ||
+ (sysrq_reset_seq_len == SYSRQ_KEY_RESET_MAX))
+ break;
+
+ sysrq_reset_seq[sysrq_reset_seq_len++] = (unsigned short)key;
+ }
+
+ /* get reset timeout if any */
+ of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms);
+}
+
static void sysrq_reinject_alt_sysrq(struct work_struct *work)
{
struct sysrq_state *sysrq =
@@ -903,6 +932,7 @@ static inline void sysrq_register_handler(void)
int error;
int i;
+ /* first check if a __weak interface was instantiated */
for (i = 0; i < ARRAY_SIZE(sysrq_reset_seq); i++) {
key = platform_sysrq_reset_seq[i];
if (key == KEY_RESERVED || key > KEY_MAX)
@@ -911,6 +941,13 @@ static inline void sysrq_register_handler(void)
sysrq_reset_seq[sysrq_reset_seq_len++] = key;
}
+ /*
+ * DT configuration takes precedence over anything
+ * that would have been defined via the __weak
+ * interface
+ */
+ sysrq_of_get_keyreset_config();
+
error = input_register_handler(&sysrq_handler);
if (error)
pr_err("Failed to register input handler, error %d", error);
--
1.8.1.2
--
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