| Message ID | 1391861250-26068-2-git-send-email-a.seppala@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Antti, On 08/02/14 12:07, Antti Seppälä wrote: > Adding a simple Manchester encoder to rc-core. > Manchester coding is used by at least RC-5 protocol and its variants. > > Signed-off-by: Antti Seppälä <a.seppala@gmail.com> > --- > drivers/media/rc/ir-raw.c | 44 +++++++++++++++++++++++++++++++++++++++++ > drivers/media/rc/rc-core-priv.h | 14 +++++++++++++ > 2 files changed, 58 insertions(+) > > diff --git a/drivers/media/rc/ir-raw.c b/drivers/media/rc/ir-raw.c > index 9d734dd..7fea9ac 100644 > --- a/drivers/media/rc/ir-raw.c > +++ b/drivers/media/rc/ir-raw.c > @@ -240,6 +240,50 @@ ir_raw_get_allowed_protocols(void) > return protocols; > } > > +int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, > + const struct ir_raw_timings_manchester *timings, > + unsigned int n, unsigned int data) > +{ > + bool need_pulse; > + int i, count = 0; > + i = 1 << (n - 1); > + > + if (n > max || max < 2) > + return -EINVAL; > + > + if (timings->pulse_space_start) { > + init_ir_raw_event_duration((*ev)++, 1, timings->clock); > + init_ir_raw_event_duration((*ev), 0, timings->clock); > + count += 2; > + } else { > + init_ir_raw_event_duration((*ev), 1, timings->clock); > + count++; > + } > + i >>= 1; If you use pulse_space_start to encode the first bit, did you mean to discard the highest bit of data? > + > + while (i > 0) { > + if (count > max) if count > max I think you've already overflowed the buffer (max is more of a max count rather than max buffer index). > + return -EINVAL; > + > + need_pulse = !(data & i); > + if (need_pulse == !!(*ev)->pulse) { > + (*ev)->duration += timings->clock; > + } else { > + init_ir_raw_event_duration(++(*ev), need_pulse, > + timings->clock); > + count++; I guess you need to check for buffer space here too. > + } > + > + init_ir_raw_event_duration(++(*ev), !need_pulse, > + timings->clock); > + count++; > + i >>= 1; > + } > + > + return 0; > +} > +EXPORT_SYMBOL(ir_raw_gen_manchester); Cheers James
Hi James. On 10 February 2014 12:25, James Hogan <james.hogan@imgtec.com> wrote: > Hi Antti, > > On 08/02/14 12:07, Antti Seppälä wrote: >> Adding a simple Manchester encoder to rc-core. >> Manchester coding is used by at least RC-5 protocol and its variants. >> >> Signed-off-by: Antti Seppälä <a.seppala@gmail.com> >> --- >> drivers/media/rc/ir-raw.c | 44 +++++++++++++++++++++++++++++++++++++++++ >> drivers/media/rc/rc-core-priv.h | 14 +++++++++++++ >> 2 files changed, 58 insertions(+) >> >> diff --git a/drivers/media/rc/ir-raw.c b/drivers/media/rc/ir-raw.c >> index 9d734dd..7fea9ac 100644 >> --- a/drivers/media/rc/ir-raw.c >> +++ b/drivers/media/rc/ir-raw.c >> @@ -240,6 +240,50 @@ ir_raw_get_allowed_protocols(void) >> return protocols; >> } >> >> +int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, >> + const struct ir_raw_timings_manchester *timings, >> + unsigned int n, unsigned int data) >> +{ >> + bool need_pulse; >> + int i, count = 0; >> + i = 1 << (n - 1); >> + >> + if (n > max || max < 2) >> + return -EINVAL; >> + >> + if (timings->pulse_space_start) { >> + init_ir_raw_event_duration((*ev)++, 1, timings->clock); >> + init_ir_raw_event_duration((*ev), 0, timings->clock); >> + count += 2; >> + } else { >> + init_ir_raw_event_duration((*ev), 1, timings->clock); >> + count++; >> + } >> + i >>= 1; > > If you use pulse_space_start to encode the first bit, did you mean to > discard the highest bit of data? > I did not mean to discard data but to just start the ir pulse with logic 1 as that first bit is discarded when decoding. >> + >> + while (i > 0) { >> + if (count > max) > > if count > max I think you've already overflowed the buffer (max is more > of a max count rather than max buffer index). > I guess you're right. I'll address this in next version of my patch. >> + return -EINVAL; >> + >> + need_pulse = !(data & i); >> + if (need_pulse == !!(*ev)->pulse) { >> + (*ev)->duration += timings->clock; >> + } else { >> + init_ir_raw_event_duration(++(*ev), need_pulse, >> + timings->clock); >> + count++; > > I guess you need to check for buffer space here too. > This comment seems also correct. Thank you for reviewing. >> + } >> + >> + init_ir_raw_event_duration(++(*ev), !need_pulse, >> + timings->clock); >> + count++; >> + i >>= 1; >> + } >> + >> + return 0; >> +} >> +EXPORT_SYMBOL(ir_raw_gen_manchester); > > Cheers > James > -- To unsubscribe from this list: send the line "unsubscribe linux-media" 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/drivers/media/rc/ir-raw.c b/drivers/media/rc/ir-raw.c index 9d734dd..7fea9ac 100644 --- a/drivers/media/rc/ir-raw.c +++ b/drivers/media/rc/ir-raw.c @@ -240,6 +240,50 @@ ir_raw_get_allowed_protocols(void) return protocols; } +int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, + const struct ir_raw_timings_manchester *timings, + unsigned int n, unsigned int data) +{ + bool need_pulse; + int i, count = 0; + i = 1 << (n - 1); + + if (n > max || max < 2) + return -EINVAL; + + if (timings->pulse_space_start) { + init_ir_raw_event_duration((*ev)++, 1, timings->clock); + init_ir_raw_event_duration((*ev), 0, timings->clock); + count += 2; + } else { + init_ir_raw_event_duration((*ev), 1, timings->clock); + count++; + } + i >>= 1; + + while (i > 0) { + if (count > max) + return -EINVAL; + + need_pulse = !(data & i); + if (need_pulse == !!(*ev)->pulse) { + (*ev)->duration += timings->clock; + } else { + init_ir_raw_event_duration(++(*ev), need_pulse, + timings->clock); + count++; + } + + init_ir_raw_event_duration(++(*ev), !need_pulse, + timings->clock); + count++; + i >>= 1; + } + + return 0; +} +EXPORT_SYMBOL(ir_raw_gen_manchester); + int ir_raw_gen_pd(struct ir_raw_event **ev, unsigned int max, const struct ir_raw_timings_pd *timings, unsigned int n, unsigned int data) diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h index 3bf8c7b..4a2e2b8 100644 --- a/drivers/media/rc/rc-core-priv.h +++ b/drivers/media/rc/rc-core-priv.h @@ -173,6 +173,20 @@ static inline void ir_raw_gen_pulse_space(struct ir_raw_event **ev, } /** + * struct ir_raw_timings_manchester - manchester coding timings + * @pulse_space_start: 1 for starting with pulse (0 for starting with space) + * @clock: duration of each pulse/space in ns + */ +struct ir_raw_timings_manchester { + unsigned int pulse_space_start:1; + unsigned int clock; +}; + +int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, + const struct ir_raw_timings_manchester *timings, + unsigned int n, unsigned int data); + +/** * struct ir_raw_timings_pd - pulse-distance modulation timings * @header_pulse: duration of header pulse in ns (0 for none) * @header_space: duration of header space in ns
Adding a simple Manchester encoder to rc-core. Manchester coding is used by at least RC-5 protocol and its variants. Signed-off-by: Antti Seppälä <a.seppala@gmail.com> --- drivers/media/rc/ir-raw.c | 44 +++++++++++++++++++++++++++++++++++++++++ drivers/media/rc/rc-core-priv.h | 14 +++++++++++++ 2 files changed, 58 insertions(+)