/* * Copyright (c) 2023 TOKITA Hiroshi * * SPDX-License-Identifier: Apache-2.0 */ #include #include #include #include #include #include #include LOG_MODULE_REGISTER(ws2812_rpi_pico_pio, CONFIG_LED_STRIP_LOG_LEVEL); #define DT_DRV_COMPAT worldsemi_ws2812_rpi_pico_pio struct ws2812_led_strip_data { uint32_t sm; }; struct ws2812_led_strip_config { const struct device *piodev; const uint8_t gpio_pin; uint8_t num_colors; size_t length; uint32_t frequency; const uint8_t *const color_mapping; uint16_t reset_delay; uint32_t cycles_per_bit; }; struct ws2812_rpi_pico_pio_config { const struct device *piodev; const struct pinctrl_dev_config *const pcfg; struct pio_program program; }; static int ws2812_led_strip_sm_init(const struct device *dev) { const struct ws2812_led_strip_config *config = dev->config; const float clkdiv = sys_clock_hw_cycles_per_sec() / (config->cycles_per_bit * config->frequency); pio_sm_config sm_config = pio_get_default_sm_config(); PIO pio; int sm; pio = pio_rpi_pico_get_pio(config->piodev); sm = pio_claim_unused_sm(pio, false); if (sm < 0) { return -EINVAL; } sm_config_set_sideset(&sm_config, 1, false, false); sm_config_set_sideset_pins(&sm_config, config->gpio_pin); sm_config_set_out_shift(&sm_config, false, true, (config->num_colors == 4 ? 32 : 24)); sm_config_set_fifo_join(&sm_config, PIO_FIFO_JOIN_TX); sm_config_set_clkdiv(&sm_config, clkdiv); pio_sm_set_consecutive_pindirs(pio, sm, config->gpio_pin, 1, true); pio_sm_init(pio, sm, -1, &sm_config); pio_sm_set_enabled(pio, sm, true); return sm; } /* * Latch current color values on strip and reset its state machines. */ static inline void ws2812_led_strip_reset_delay(uint16_t delay) { k_usleep(delay); } static int ws2812_led_strip_update_rgb(const struct device *dev, struct led_rgb *pixels, size_t num_pixels) { const struct ws2812_led_strip_config *config = dev->config; struct ws2812_led_strip_data *data = dev->data; PIO pio = pio_rpi_pico_get_pio(config->piodev); for (size_t i = 0; i < num_pixels; i++) { uint32_t color = 0; for (size_t j = 0; j < config->num_colors; j++) { switch (config->color_mapping[j]) { /* White channel is not supported by LED strip API. */ case LED_COLOR_ID_WHITE: color |= 0; break; case LED_COLOR_ID_RED: color |= pixels[i].r << (8 * (2 - j)); break; case LED_COLOR_ID_GREEN: color |= pixels[i].g << (8 * (2 - j)); break; case LED_COLOR_ID_BLUE: color |= pixels[i].b << (8 * (2 - j)); break; } } pio_sm_put_blocking(pio, data->sm, color << (config->num_colors == 4 ? 0 : 8)); } ws2812_led_strip_reset_delay(config->reset_delay); return 0; } static size_t ws2812_led_strip_length(const struct device *dev) { const struct ws2812_led_strip_config *config = dev->config; return config->length; } static const struct led_strip_driver_api ws2812_led_strip_api = { .update_rgb = ws2812_led_strip_update_rgb, .length = ws2812_led_strip_length, }; /* * Retrieve the channel to color mapping (e.g. RGB, BGR, GRB, ...) from the * "color-mapping" DT property. */ static int ws2812_led_strip_init(const struct device *dev) { const struct ws2812_led_strip_config *config = dev->config; struct ws2812_led_strip_data *data = dev->data; int sm; if (!device_is_ready(config->piodev)) { LOG_ERR("%s: PIO device not ready", dev->name); return -ENODEV; } for (uint32_t i = 0; i < config->num_colors; i++) { switch (config->color_mapping[i]) { case LED_COLOR_ID_WHITE: case LED_COLOR_ID_RED: case LED_COLOR_ID_GREEN: case LED_COLOR_ID_BLUE: break; default: LOG_ERR("%s: invalid channel to color mapping." " Check the color-mapping DT property", dev->name); return -EINVAL; } } sm = ws2812_led_strip_sm_init(dev); if (sm < 0) { return sm; } data->sm = sm; return 0; } static int ws2812_rpi_pico_pio_init(const struct device *dev) { const struct ws2812_rpi_pico_pio_config *config = dev->config; PIO pio; if (!device_is_ready(config->piodev)) { LOG_ERR("%s: PIO device not ready", dev->name); return -ENODEV; } pio = pio_rpi_pico_get_pio(config->piodev); pio_add_program(pio, &config->program); return pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT); } #define CYCLES_PER_BIT(node) \ (DT_PROP_BY_IDX(node, bit_waveform, 0) + DT_PROP_BY_IDX(node, bit_waveform, 1) + \ DT_PROP_BY_IDX(node, bit_waveform, 2)) #define WS2812_CHILD_INIT(node) \ static const uint8_t ws2812_led_strip_##node##_color_mapping[] = \ DT_PROP(node, color_mapping); \ struct ws2812_led_strip_data ws2812_led_strip_##node##_data; \ \ static const struct ws2812_led_strip_config ws2812_led_strip_##node##_config = { \ .piodev = DEVICE_DT_GET(DT_PARENT(DT_PARENT(node))), \ .gpio_pin = DT_GPIO_PIN_BY_IDX(node, gpios, 0), \ .num_colors = DT_PROP_LEN(node, color_mapping), \ .length = DT_PROP(node, chain_length), \ .color_mapping = ws2812_led_strip_##node##_color_mapping, \ .reset_delay = DT_PROP(node, reset_delay), \ .frequency = DT_PROP(node, frequency), \ .cycles_per_bit = CYCLES_PER_BIT(DT_PARENT(node)), \ }; \ \ DEVICE_DT_DEFINE(node, &ws2812_led_strip_init, NULL, &ws2812_led_strip_##node##_data, \ &ws2812_led_strip_##node##_config, POST_KERNEL, \ CONFIG_LED_STRIP_INIT_PRIORITY, &ws2812_led_strip_api); #define SET_DELAY(op, inst, i) \ (op | (((DT_INST_PROP_BY_IDX(inst, bit_waveform, i) - 1) & 0xF) << 8)) /* * This pio program runs [T0+T1+T2] cycles per 1 loop. * The first `out` instruction outputs 0 by [T2] times to the sideset pin. * These zeros are padding. Here is the start of actual data transmission. * The second `jmp` instruction output 1 by [T0] times to the sideset pin. * This `jmp` instruction jumps to line 3 if the value of register x is true. * Otherwise, jump to line 4. * The third `jmp` instruction outputs 1 by [T1] times to the sideset pin. * After output, return to the first line. * The fourth `jmp` instruction outputs 0 by [T1] times. * After output, return to the first line and output 0 by [T2] times. * * In the case of configuration, T0=3, T1=3, T2 =4, * the final output is 1110000000 in case register x is false. * It represents code 0, defined in the datasheet. * And outputs 1111110000 in case of x is true. It represents code 1. */ #define WS2812_RPI_PICO_PIO_INIT(inst) \ PINCTRL_DT_INST_DEFINE(inst); \ \ DT_INST_FOREACH_CHILD_STATUS_OKAY(inst, WS2812_CHILD_INIT); \ \ static const uint16_t rpi_pico_pio_ws2812_instructions_##inst[] = { \ SET_DELAY(0x6021, inst, 2), /* 0: out x, 1 side 0 [T2 - 1] */ \ SET_DELAY(0x1023, inst, 0), /* 1: jmp !x, 3 side 1 [T0 - 1] */ \ SET_DELAY(0x1000, inst, 1), /* 2: jmp 0 side 1 [T1 - 1] */ \ SET_DELAY(0x0000, inst, 1), /* 3: jmp 0 side 0 [T1 - 1] */ \ }; \ \ static const struct ws2812_rpi_pico_pio_config rpi_pico_pio_ws2812_##inst##_config = { \ .piodev = DEVICE_DT_GET(DT_INST_PARENT(inst)), \ .pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst), \ .program = \ { \ .instructions = rpi_pico_pio_ws2812_instructions_##inst, \ .length = ARRAY_SIZE(rpi_pico_pio_ws2812_instructions_##inst), \ .origin = -1, \ }, \ }; \ \ DEVICE_DT_INST_DEFINE(inst, &ws2812_rpi_pico_pio_init, NULL, NULL, \ &rpi_pico_pio_ws2812_##inst##_config, POST_KERNEL, \ CONFIG_LED_STRIP_INIT_PRIORITY, NULL); DT_INST_FOREACH_STATUS_OKAY(WS2812_RPI_PICO_PIO_INIT)