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Posted to commits@nuttx.apache.org by bt...@apache.org on 2022/08/13 17:01:33 UTC
[incubator-nuttx] branch master updated: drivers/leds/ws2812: Revert SPI frequency change
This is an automated email from the ASF dual-hosted git repository.
btashton 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 e1e89b925f drivers/leds/ws2812: Revert SPI frequency change
e1e89b925f is described below
commit e1e89b925fc7bf6a66f85ce5853ab3a9101eae05
Author: Diego Herranz <di...@diegoherranz.com>
AuthorDate: Sat Aug 13 17:33:10 2022 +0200
drivers/leds/ws2812: Revert SPI frequency change
https://github.com/apache/incubator-nuttx/commit/0c3db448bb64c8877a4dfa62416027b24a639a8e
added the option to generate the waveforms to drive ws2812 and similar LEDs using different
hardware (e.g. RP2040 PIO instead of SPI).
For that new mode, the concept of CONFIG_WS2812_FREQUENCY is different. Instead of
the SPI frequency (commonly a few MHz), it is the frequency of the actual output waveform
(commonly 400 or 800 kHz).
There was an attempt to express the SPI frequency divided by 10, but it's not actually the
case either (it would be divided by 8).
I think it is clearer to explain in Kconfig what CONFIG_WS2812_FREQUENCY means for each mode
and go back to the previous behaviour for the original SPI mode (also to avoid breaking
out-of-tree boards).
---
drivers/leds/Kconfig | 12 ++++++++----
drivers/leds/ws2812.c | 8 ++++----
2 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ad23a4ca94..f2525a81ea 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -148,9 +148,13 @@ config WS2812_FREQUENCY
default 800000
depends on WS2812
---help---
- This is should be set to the bit frequency of the
- ws2812s being used. Newer chips use an 800 kHz
- bit frequency (the default); although, some older
- chips run at 400 kHz.
+ Frequency in Hz.
+ On SPI mode (WS2812_NON_SPI_DRIVER not selected), this is
+ the SPI frequency (commonly a few MHz) to generate the required
+ waveforms to represent a 0/1 symbol.
+ On non SPI mode (WS2812_NON_SPI_DRIVER selected), this should be set
+ to the bit frequency of the ws2812s being used. Newer chips use an
+ 800 kHz bit frequency (the default); although, some older chips run
+ at 400 kHz.
endmenu # LED Support
diff --git a/drivers/leds/ws2812.c b/drivers/leds/ws2812.c
index 0919d3f500..f47fd2e61b 100644
--- a/drivers/leds/ws2812.c
+++ b/drivers/leds/ws2812.c
@@ -78,10 +78,10 @@
* Reset: low signal >50us
*/
-#if CONFIG_WS2812_FREQUENCY >= 360000 && CONFIG_WS2812_FREQUENCY <= 500000
+#if CONFIG_WS2812_FREQUENCY >= 3600000 && CONFIG_WS2812_FREQUENCY <= 5000000
# define WS2812_ZERO_BYTE 0b01000000 /* 200ns at 5 MHz, 278ns at 3.6 MHz */
# define WS2812_ONE_BYTE 0b01110000 /* 600ns at 5 MHz, 833ns at 3.6 MHz */
-#elif CONFIG_WS2812_FREQUENCY >= 590000 && CONFIG_WS2812_FREQUENCY <= 900000
+#elif CONFIG_WS2812_FREQUENCY >= 5900000 && CONFIG_WS2812_FREQUENCY <= 9000000
# define WS2812_ZERO_BYTE 0b01100000 /* 222ns at 9 MHz, 339ns at 5.9 MHz */
# define WS2812_ONE_BYTE 0b01111100 /* 556ns at 9 MHz, 847ns at 5.9 MHz */
#else
@@ -93,7 +93,7 @@
* Aiming for 60 us, safely above the 50us required.
*/
-#define WS2812_RST_CYCLES (CONFIG_WS2812_FREQUENCY * 60 / 100000 / 8)
+#define WS2812_RST_CYCLES (CONFIG_WS2812_FREQUENCY * 60 / 1000000 / 8)
#define WS2812_BYTES_PER_LED (8 * 3)
@@ -389,7 +389,7 @@ static inline void ws2812_configspi(FAR struct spi_dev_s *spi)
SPI_SETMODE(spi, SPIDEV_MODE3);
SPI_SETBITS(spi, 8);
SPI_HWFEATURES(spi, 0);
- SPI_SETFREQUENCY(spi, 10 * CONFIG_WS2812_FREQUENCY);
+ SPI_SETFREQUENCY(spi, CONFIG_WS2812_FREQUENCY);
}
/****************************************************************************