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drivers/led/ws2812: fix comments

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Complete or improve some explanations and fix some typos
This commit is contained in:
Diego Herranz 2020-12-02 21:21:36 +00:00 committed by Brennan Ashton
parent 09b6aca971
commit 117947b5a1
1 changed files with 9 additions and 9 deletions
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18
drivers/leds/ws2812.c
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@ -39,16 +39,16 @@
* Pre-processor Definitions
****************************************************************************/
/* These are the tuning parameters to meeting timeing requirements */
/* These are the tuning parameters to meet timing requirements */
#if CONFIG_WS2812_FREQUENCY == 4000000
# define WS2812_RST_CYCLES 30 /* 60us (>50us)*/
# define WS2812_RST_CYCLES 30 /* 60us (>50us) */
# define WS2812_ZERO_BYTE 0b01000000 /* 250 ns (200ns - 500ns) */
# define WS2812_ONE_BYTE 0b01110000 /* 750 ns (550ns - 850ns) */
#elif CONFIG_WS2812_FREQUENCY == 8000000
# define WS2812_RST_CYCLES 60 /* 60us (>50us)*/
# define WS2812_RST_CYCLES 60 /* 60us (>50us) */
# define WS2812_ZERO_BYTE 0b01100000 /* 250 ns (200ns - 500ns) */
# define WS2812_ONE_BYTE 0b01111100 /* 750 ns (550ns - 850ns) */
# define WS2812_ONE_BYTE 0b01111100 /* 625 ns (550ns - 850ns) */
#else
# error "Unsupported SPI Frequency"
#endif
@ -60,11 +60,11 @@
* [<----reset bytes---->|<-RGBn->...<-RGB0->|<----reset bytes---->]
*
* It is important that this is shipped as close to one chunk as possible
* in order to meet timeing requirements and to keep MOSI from going high
* in order to meet timing requirements and to keep MOSI from going high
* between transactions. Some chips will leave MOSI at the state of the
* MSB of the last byte for this reason it is recommended to shift the
* bytes that represents the zero and one so that the MSB is 1. The reset
* clocks will pad the shortend low at the end.
* bits that represents the zero or one waveform so that the MSB is 0.
* The reset clocks will pad the shortened low at the end.
*/
#define TXBUFF_SIZE(n) (WS2812_RST_CYCLES * 2 + n * WS2812_BYTES_PER_LED)
@ -250,7 +250,7 @@ static ssize_t ws2812_write(FAR struct file *filep, FAR const char *buffer,
return -1;
}
/* We need at least one display, so 1 byte */
/* We need at least one LED, so 1 byte */
if (buflen < 1)
{
@ -309,7 +309,7 @@ static ssize_t ws2812_write(FAR struct file *filep, FAR const char *buffer,
* Description:
* This routine is called when seeking the WS2812 device. This can be used
* to address the starting LED to write. This should be done on a full
* color boundary which is 32bits. e.g. LED0 - offset 0 LED 8.
* color boundary which is 32bits. e.g. LED0 - offset 0, LED 8 - offset 32
*
****************************************************************************/