diff mbox

[v6] Input: sysrq - DT binding for key sequence

Message ID 1375115638-21236-1-git-send-email-mathieu.poirier@linaro.org
State New, archived
Headers show

Commit Message

Mathieu Poirier July 29, 2013, 4:33 p.m. UTC
From: "Mathieu J. Poirier" <mathieu.poirier@linaro.org>

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@linaro.org>
---
changes for v6:
  - Made binding description more specific.  'sysrq-reset-seq's definition
    was enhanced and the case where 'timeout-ms' is omitted clearly
    explained.
---
 .../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

Comments

grant.likely@linaro.org July 30, 2013, 4:09 a.m. UTC | #1
On Mon, Jul 29, 2013 at 10:33 AM,  <mathieu.poirier@linaro.org> wrote:
> From: "Mathieu J. Poirier" <mathieu.poirier@linaro.org>
>
> 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@linaro.org>

Acked-by: Grant Likely <grant.likely@linaro.org>

g.

> ---
> changes for v6:
>   - Made binding description more specific.  'sysrq-reset-seq's definition
>     was enhanced and the case where 'timeout-ms' is omitted clearly
>     explained.
> ---
>  .../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..13421a9
> --- /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 Linux keycodes, one keycode per cell.
> +
> +Optional property:
> +timeout-ms: duration keys must be pressed together in milliseconds
> +before generating a sysrq.  If omitted the system is rebooted
> +immediately when a valid sequence has beend recognized.
> +
> +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 d5cc3ac..b04a24d 100644
> --- a/drivers/tty/sysrq.c
> +++ b/drivers/tty/sysrq.c
> @@ -45,6 +45,7 @@
>  #include <linux/moduleparam.h>
>  #include <linux/jiffies.h>
>  #include <linux/syscalls.h>
> +#include <linux/of.h>
>
>  #include <asm/ptrace.h>
>  #include <asm/irq_regs.h>
> @@ -681,6 +682,34 @@ 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 =
> @@ -914,6 +943,7 @@ 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)
> @@ -922,6 +952,13 @@ 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
>
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Dmitry Torokhov Aug. 4, 2013, 12:30 a.m. UTC | #2
On Mon, Jul 29, 2013 at 10:09:54PM -0600, Grant Likely wrote:
> On Mon, Jul 29, 2013 at 10:33 AM,  <mathieu.poirier@linaro.org> wrote:
> > From: "Mathieu J. Poirier" <mathieu.poirier@linaro.org>
> >
> > 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@linaro.org>
> 
> Acked-by: Grant Likely <grant.likely@linaro.org>

Applied, thank you.
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/input/input-reset.txt b/Documentation/devicetree/bindings/input/input-reset.txt
new file mode 100644
index 0000000..13421a9
--- /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 Linux keycodes, one keycode per cell.
+
+Optional property:
+timeout-ms: duration keys must be pressed together in milliseconds
+before generating a sysrq.  If omitted the system is rebooted
+immediately when a valid sequence has beend recognized.
+
+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 d5cc3ac..b04a24d 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -45,6 +45,7 @@ 
 #include <linux/moduleparam.h>
 #include <linux/jiffies.h>
 #include <linux/syscalls.h>
+#include <linux/of.h>
 
 #include <asm/ptrace.h>
 #include <asm/irq_regs.h>
@@ -681,6 +682,34 @@  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 =
@@ -914,6 +943,7 @@  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)
@@ -922,6 +952,13 @@  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);