summaryrefslogtreecommitdiff
path: root/platforms/chibios/drivers/ws2812_spi.c
blob: 377a929b9445f125cd063c760a121ae88664f09e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
#include "quantum.h"
#include "ws2812.h"

/* Adapted from https://github.com/gamazeps/ws2812b-chibios-SPIDMA/ */

#ifdef RGBW
#    error "RGBW not supported"
#endif

// Define the spi your LEDs are plugged to here
#ifndef WS2812_SPI
#    define WS2812_SPI SPID1
#endif

#ifndef WS2812_SPI_MOSI_PAL_MODE
#    define WS2812_SPI_MOSI_PAL_MODE 5
#endif

#ifndef WS2812_SPI_SCK_PAL_MODE
#    define WS2812_SPI_SCK_PAL_MODE 5
#endif

// Push Pull or Open Drain Configuration
// Default Push Pull
#ifndef WS2812_EXTERNAL_PULLUP
#    if defined(USE_GPIOV1)
#        define WS2812_MOSI_OUTPUT_MODE PAL_MODE_STM32_ALTERNATE_PUSHPULL
#    else
#        define WS2812_MOSI_OUTPUT_MODE PAL_MODE_ALTERNATE(WS2812_SPI_MOSI_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL
#    endif
#else
#    if defined(USE_GPIOV1)
#        define WS2812_MOSI_OUTPUT_MODE PAL_MODE_STM32_ALTERNATE_OPENDRAIN
#    else
#        define WS2812_MOSI_OUTPUT_MODE PAL_MODE_ALTERNATE(WS2812_SPI_MOSI_PAL_MODE) | PAL_STM32_OTYPE_OPENDRAIN
#    endif
#endif

// Define SPI config speed
// baudrate should target 3.2MHz
// F072 fpclk = 48MHz
// 48/16 = 3Mhz
#if WS2812_SPI_DIVISOR == 2
#    define WS2812_SPI_DIVISOR (0)
#elif WS2812_SPI_DIVISOR == 4
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_0)
#elif WS2812_SPI_DIVISOR == 8
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_1)
#elif WS2812_SPI_DIVISOR == 16  // same as default
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_1 | SPI_CR1_BR_0)
#elif WS2812_SPI_DIVISOR == 32
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_2)
#elif WS2812_SPI_DIVISOR == 64
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_2 | SPI_CR1_BR_0)
#elif WS2812_SPI_DIVISOR == 128
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_2 | SPI_CR1_BR_1)
#elif WS2812_SPI_DIVISOR == 256
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_2 | SPI_CR1_BR_1 | SPI_CR1_BR_0)
#else
#    define WS2812_SPI_DIVISOR (SPI_CR1_BR_1 | SPI_CR1_BR_0)  // default
#endif

// Use SPI circular buffer
#ifdef WS2812_SPI_USE_CIRCULAR_BUFFER
#    define WS2812_SPI_BUFFER_MODE 1  // circular buffer
#else
#    define WS2812_SPI_BUFFER_MODE 0  // normal buffer
#endif

#if defined(USE_GPIOV1)
#    define WS2812_SCK_OUTPUT_MODE PAL_MODE_STM32_ALTERNATE_PUSHPULL
#else
#    define WS2812_SCK_OUTPUT_MODE PAL_MODE_ALTERNATE(WS2812_SPI_SCK_PAL_MODE) | PAL_STM32_OTYPE_PUSHPULL
#endif

#define BYTES_FOR_LED_BYTE 4
#define NB_COLORS 3
#define BYTES_FOR_LED (BYTES_FOR_LED_BYTE * NB_COLORS)
#define DATA_SIZE (BYTES_FOR_LED * RGBLED_NUM)
#define RESET_SIZE (1000 * WS2812_TRST_US / (2 * 1250))
#define PREAMBLE_SIZE 4

static uint8_t txbuf[PREAMBLE_SIZE + DATA_SIZE + RESET_SIZE] = {0};

/*
 * As the trick here is to use the SPI to send a huge pattern of 0 and 1 to
 * the ws2812b protocol, we use this helper function to translate bytes into
 * 0s and 1s for the LED (with the appropriate timing).
 */
static uint8_t get_protocol_eq(uint8_t data, int pos) {
    uint8_t eq = 0;
    if (data & (1 << (2 * (3 - pos))))
        eq = 0b1110;
    else
        eq = 0b1000;
    if (data & (2 << (2 * (3 - pos))))
        eq += 0b11100000;
    else
        eq += 0b10000000;
    return eq;
}

static void set_led_color_rgb(LED_TYPE color, int pos) {
    uint8_t* tx_start = &txbuf[PREAMBLE_SIZE];

#if (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_GRB)
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + j] = get_protocol_eq(color.g, j);
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE + j] = get_protocol_eq(color.r, j);
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE * 2 + j] = get_protocol_eq(color.b, j);
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_RGB)
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + j] = get_protocol_eq(color.r, j);
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE + j] = get_protocol_eq(color.g, j);
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE * 2 + j] = get_protocol_eq(color.b, j);
#elif (WS2812_BYTE_ORDER == WS2812_BYTE_ORDER_BGR)
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + j] = get_protocol_eq(color.b, j);
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE + j] = get_protocol_eq(color.g, j);
    for (int j = 0; j < 4; j++) tx_start[BYTES_FOR_LED * pos + BYTES_FOR_LED_BYTE * 2 + j] = get_protocol_eq(color.r, j);
#endif
}

void ws2812_init(void) {
    palSetLineMode(RGB_DI_PIN, WS2812_MOSI_OUTPUT_MODE);

#ifdef WS2812_SPI_SCK_PIN
    palSetLineMode(WS2812_SPI_SCK_PIN, WS2812_SCK_OUTPUT_MODE);
#endif  // WS2812_SPI_SCK_PIN

    // TODO: more dynamic baudrate
    static const SPIConfig spicfg = {WS2812_SPI_BUFFER_MODE, NULL, PAL_PORT(RGB_DI_PIN), PAL_PAD(RGB_DI_PIN), WS2812_SPI_DIVISOR};

    spiAcquireBus(&WS2812_SPI);     /* Acquire ownership of the bus.    */
    spiStart(&WS2812_SPI, &spicfg); /* Setup transfer parameters.       */
    spiSelect(&WS2812_SPI);         /* Slave Select assertion.          */
#ifdef WS2812_SPI_USE_CIRCULAR_BUFFER
    spiStartSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
#endif
}

void ws2812_setleds(LED_TYPE* ledarray, uint16_t leds) {
    static bool s_init = false;
    if (!s_init) {
        ws2812_init();
        s_init = true;
    }

    for (uint8_t i = 0; i < leds; i++) {
        set_led_color_rgb(ledarray[i], i);
    }

    // Send async - each led takes ~0.03ms, 50 leds ~1.5ms, animations flushing faster than send will cause issues.
    // Instead spiSend can be used to send synchronously (or the thread logic can be added back).
#ifndef WS2812_SPI_USE_CIRCULAR_BUFFER
#    ifdef WS2812_SPI_SYNC
    spiSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
#    else
    spiStartSend(&WS2812_SPI, sizeof(txbuf) / sizeof(txbuf[0]), txbuf);
#    endif
#endif
}