[incubator-nuttx] branch master updated: In case of SAMV7 it is possible to overwrite the pwm output with 0 or 1 immediately. Changing the dutycycle to 0 or 100 will take effect only on end of cycle, which could be to late for some applications.

[xiaoxiang]

This is an automated email from the ASF dual-hosted git repository.

xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 6376d90c3d In case of SAMV7 it is possible to overwrite the pwm output 
with 0 or 1 immediately. Changing the dutycycle to 0 or 100 will take effect 
only on end of cycle, which could be to late for some applications.
6376d90c3d is described below

commit 6376d90c3d9997c339425dbb3e102ef80ddf3d54
Author: Simon Filgis <si...@ingenieurbuero-filgis.de>
AuthorDate: Tue Nov 15 20:41:25 2022 +0100

    In case of SAMV7 it is possible to overwrite the pwm output with 0 or 1 
immediately. Changing the dutycycle to 0 or 100 will take effect only on end of 
cycle, which could be to late for some applications.
    
    This solution adds a overwrite flag and value when updating the duty cycle.
---
 arch/arm/src/samv7/sam_pwm.c | 18 ++++++++++++++++++
 include/nuttx/timers/pwm.h   |  4 ++++
 2 files changed, 22 insertions(+)

diff --git a/arch/arm/src/samv7/sam_pwm.c b/arch/arm/src/samv7/sam_pwm.c
index e446c60248..28205e4fe0 100644
--- a/arch/arm/src/samv7/sam_pwm.c
+++ b/arch/arm/src/samv7/sam_pwm.c
@@ -449,6 +449,7 @@ static int pwm_start(struct pwm_lowerhalf_s *dev,
                      const struct pwm_info_s *info)
 {
   struct sam_pwm_s *priv = (struct sam_pwm_s *)dev;
+  uint32_t regval;
 
 #ifdef CONFIG_PWM_MULTICHAN
       for (int i = 0; i < PWM_NCHANNELS; i++)
@@ -472,6 +473,23 @@ static int pwm_start(struct pwm_lowerhalf_s *dev,
                            info->frequency);
               pwm_set_output(dev, priv->channels[index - 1].channel,
                              info->channels[i].duty);
+
+          if (info->channels[i].ch_outp_ovrwr)
+            {
+              regval = pwm_getreg(priv, SAMV7_PWM_OOV);
+              regval &= ~(info->channels[i].ch_outp_ovrwr_val
+                  << priv->channels[i].channel);
+              pwm_putreg(priv, SAMV7_PWM_OOV, regval);
+
+              regval = (1 << priv->channels[i].channel);
+              pwm_putreg(priv, SAMV7_PWM_OSS, regval);
+            }
+          else
+            {
+              /* release overwrite of channel */
+              regval = (1 << priv->channels[i].channel);
+              pwm_putreg(priv, SAMV7_PWM_OSC, regval);
+            }
             }
         }
 #else
diff --git a/include/nuttx/timers/pwm.h b/include/nuttx/timers/pwm.h
index dccbb991c4..75ff9ba50a 100644
--- a/include/nuttx/timers/pwm.h
+++ b/include/nuttx/timers/pwm.h
@@ -120,6 +120,10 @@
 struct pwm_chan_s
 {
   ub16_t duty;
+#ifdef CONFIG_SAMV7_PWM
+  bool ch_outp_ovrwr;
+  bool ch_outp_ovrwr_val;
+#endif
   int8_t channel;
 };
 #endif