| Message ID | 1373902598-10062-1-git-send-email-mathieu.poirier@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/15/2013 10:36 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> > --- > changes for v4: > - Moved seach of reset sequence nodes to a single call. > --- > .../devicetree/bindings/input/input-reset.txt | 34 ++++++++++++++ > drivers/tty/sysrq.c | 54 ++++++++++++++++++++++ > 2 files changed, 88 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..79504af > --- /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 microseconds milliseconds (ms) or microseconds (us)? > +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..01a8729 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 +672,50 @@ static void sysrq_detect_reset_sequence(struct sysrq_state *state, > } > } > > +static void sysrq_of_get_keyreset_config(void) > +{ > + unsigned short key; > + struct device_node *np; > + const struct property *prop; > + const __be32 *val; > + int count, i; > + > + np = of_find_node_by_path("/chosen/linux,sysrq-reset-seq"); > + if (!np) { > + pr_debug("No sysrq node found"); > + goto out; > + } > + > + prop = of_find_property(np, "keyset", NULL); > + if (!prop || !prop->value) { > + pr_err("Invalid input keyset"); > + goto out; > + } > + > + count = prop->length / sizeof(u32); > + val = prop->value; None of the existing helpers to retrieve property arrays doesn't work here? > + > + if (count > SYSRQ_KEY_RESET_MAX) > + count = SYSRQ_KEY_RESET_MAX; > + > + /* reset in case a __weak definition was present */ > + sysrq_reset_seq_len = 0; > + > + for (i = 0; i < count; i++) { > + key = (unsigned short)be32_to_cpup(val++); > + if (key == KEY_RESERVED || key > KEY_MAX) > + break; > + > + sysrq_reset_seq[sysrq_reset_seq_len++] = key; > + } > + > + /* get reset timeout if any */ > + of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms); > + > + out: > + ; > +} > + > static void sysrq_reinject_alt_sysrq(struct work_struct *work) > { > struct sysrq_state *sysrq = > @@ -688,6 +733,7 @@ static void sysrq_reinject_alt_sysrq(struct work_struct *work) > input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1); > input_inject_event(handle, EV_SYN, SYN_REPORT, 1); > > + spurious ws change > input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0); > input_inject_event(handle, EV_KEY, alt_code, 0); > input_inject_event(handle, EV_SYN, SYN_REPORT, 1); > @@ -903,6 +949,7 @@ 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 +958,13 @@ 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); > -- 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
On Tue, Jul 16, 2013 at 5:24 PM, Mathieu Poirier <mathieu.poirier@linaro.org> wrote: > > > > On 15 July 2013 20:43, Rob Herring <robherring2@gmail.com> wrote: >> >> On 07/15/2013 10:36 AM, mathieu.poirier@linaro.org wrote: >> > From: "Mathieu J. Poirier" <mathieu.poirier@linaro.org> >> > [snip] >> > + prop = of_find_property(np, "keyset", NULL); >> > + if (!prop || !prop->value) { >> > + pr_err("Invalid input keyset"); >> > + goto out; >> > + } >> > + >> > + count = prop->length / sizeof(u32); >> > + val = prop->value; >> >> None of the existing helpers to retrieve property arrays doesn't work >> here? > > > The problem here is that we never know how long the sequence will be. As > such the 'of_property_read_uXY_array' functions won't work. Or maybe you're > referring to another set of helpers... If so, please clarify. What about of_property_for_each_u32? Or we should make of_property_read_uXY_array work with arrays that can be less than some max size. Rob -- 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
diff --git a/Documentation/devicetree/bindings/input/input-reset.txt b/Documentation/devicetree/bindings/input/input-reset.txt new file mode 100644 index 0000000..79504af --- /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 microseconds +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..01a8729 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 +672,50 @@ static void sysrq_detect_reset_sequence(struct sysrq_state *state, } } +static void sysrq_of_get_keyreset_config(void) +{ + unsigned short key; + struct device_node *np; + const struct property *prop; + const __be32 *val; + int count, i; + + np = of_find_node_by_path("/chosen/linux,sysrq-reset-seq"); + if (!np) { + pr_debug("No sysrq node found"); + goto out; + } + + prop = of_find_property(np, "keyset", NULL); + if (!prop || !prop->value) { + pr_err("Invalid input keyset"); + goto out; + } + + count = prop->length / sizeof(u32); + val = prop->value; + + if (count > SYSRQ_KEY_RESET_MAX) + count = SYSRQ_KEY_RESET_MAX; + + /* reset in case a __weak definition was present */ + sysrq_reset_seq_len = 0; + + for (i = 0; i < count; i++) { + key = (unsigned short)be32_to_cpup(val++); + if (key == KEY_RESERVED || key > KEY_MAX) + break; + + sysrq_reset_seq[sysrq_reset_seq_len++] = key; + } + + /* get reset timeout if any */ + of_property_read_u32(np, "timeout-ms", &sysrq_reset_downtime_ms); + + out: + ; +} + static void sysrq_reinject_alt_sysrq(struct work_struct *work) { struct sysrq_state *sysrq = @@ -688,6 +733,7 @@ static void sysrq_reinject_alt_sysrq(struct work_struct *work) input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1); input_inject_event(handle, EV_SYN, SYN_REPORT, 1); + input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0); input_inject_event(handle, EV_KEY, alt_code, 0); input_inject_event(handle, EV_SYN, SYN_REPORT, 1); @@ -903,6 +949,7 @@ 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 +958,13 @@ 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);