From 6699d4d4f931f5f686bae65da5f89589395d86ba Mon Sep 17 00:00:00 2001 From: TOKITA Hiroshi Date: Sat, 25 Feb 2023 09:00:59 +0900 Subject: [PATCH] drivers: led_strip: add rpi_pico's PIO based ws2812 driver Add driver that based on RPI-PICO's PIO feature for ws2812. This driver can handle WS2812 or compatible LED strips. The single PIO node can handle up to 4 strips. Any pins that can be configured for PIO can be used for strips. I verified the samples/driver/led_ws2812 sample working with WS2812(144 pcs) led strip using following patches. - samples/drivers/led_ws2812/boards/rpi_pico.overlay ``` / { aliases { led-strip = &ws2812; }; }; &pinctrl { ws2812_pio0_default: ws2812_pio0_default { ws2812 { pinmux = ; }; }; }; &pio0 { status = "okay"; pio-ws2812 { compatible = "worldsemi,ws2812-rpi_pico-pio"; status = "okay"; pinctrl-0 = <&ws2812_pio0_default>; pinctrl-names = "default"; bit-waveform = <3>, <3>, <4>; ws2812: ws2812 { status = "okay"; output-pin = <21>; chain-length = <144>; color-mapping = ; reset-delay = <280>; frequency = <800000>; }; }; }; ``` - samples/drivers/led_ws2812/boards/rpi_pico.conf ``` CONFIG_WS2812_STRIP_RPI_PICO_PIO=y ``` Signed-off-by: TOKITA Hiroshi --- drivers/led_strip/CMakeLists.txt | 1 + drivers/led_strip/Kconfig.ws2812 | 7 + drivers/led_strip/ws2812_rpi_pico_pio.c | 249 ++++++++++++++++++ .../worldsemi,ws2812-rpi_pico-pio.yaml | 68 +++++ 4 files changed, 325 insertions(+) create mode 100644 drivers/led_strip/ws2812_rpi_pico_pio.c create mode 100644 dts/bindings/led_strip/worldsemi,ws2812-rpi_pico-pio.yaml diff --git a/drivers/led_strip/CMakeLists.txt b/drivers/led_strip/CMakeLists.txt index 6c950cac59..aa4e95722a 100644 --- a/drivers/led_strip/CMakeLists.txt +++ b/drivers/led_strip/CMakeLists.txt @@ -7,4 +7,5 @@ zephyr_library_sources_ifdef(CONFIG_LPD880X_STRIP lpd880x.c) zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_GPIO ws2812_gpio.c) zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_SPI ws2812_spi.c) zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_I2S ws2812_i2s.c) +zephyr_library_sources_ifdef(CONFIG_WS2812_STRIP_RPI_PICO_PIO ws2812_rpi_pico_pio.c) zephyr_library_sources_ifdef(CONFIG_TLC5971_STRIP tlc5971.c) diff --git a/drivers/led_strip/Kconfig.ws2812 b/drivers/led_strip/Kconfig.ws2812 index 7682ba4be8..469b6d3f91 100644 --- a/drivers/led_strip/Kconfig.ws2812 +++ b/drivers/led_strip/Kconfig.ws2812 @@ -46,4 +46,11 @@ config WS2812_STRIP_GPIO Note that this driver is not compatible with the Everlight B1414 controller. +config WS2812_STRIP_RPI_PICO_PIO + bool "Raspberry Pi Pico PIO" + depends on DT_HAS_WORLDSEMI_WS2812_RPI_PICO_PIO_ENABLED + select PICOSDK_USE_PIO + help + Use the PIO feature available on RaspberryPi Pico devices. + endchoice diff --git a/drivers/led_strip/ws2812_rpi_pico_pio.c b/drivers/led_strip/ws2812_rpi_pico_pio.c new file mode 100644 index 0000000000..b2bb265497 --- /dev/null +++ b/drivers/led_strip/ws2812_rpi_pico_pio.c @@ -0,0 +1,249 @@ +/* + * Copyright (c) 2023 TOKITA Hiroshi + * + * SPDX-License-Identifier: Apache-2.0 + */ + +#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; + uint32_t output_pin; + uint8_t num_colors; + 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->output_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->output_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 int ws2812_led_strip_update_channels(const struct device *dev, uint8_t *channels, + size_t num_channels) +{ + LOG_DBG("update_channels not implemented"); + return -ENOTSUP; +} + +static const struct led_strip_driver_api ws2812_led_strip_api = { + .update_rgb = ws2812_led_strip_update_rgb, + .update_channels = ws2812_led_strip_update_channels, +}; + +/* + * 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))), \ + .output_pin = DT_PROP(node, output_pin), \ + .num_colors = DT_PROP_LEN(node, color_mapping), \ + .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) diff --git a/dts/bindings/led_strip/worldsemi,ws2812-rpi_pico-pio.yaml b/dts/bindings/led_strip/worldsemi,ws2812-rpi_pico-pio.yaml new file mode 100644 index 0000000000..d5d41ed38e --- /dev/null +++ b/dts/bindings/led_strip/worldsemi,ws2812-rpi_pico-pio.yaml @@ -0,0 +1,68 @@ +# Copyright (c) 2023, TOKITA Hiroshi +# SPDX-License-Identifier: Apache-2.0 + +description: | + The pio node configured for ws2812. + +compatible: "worldsemi,ws2812-rpi_pico-pio" + +include: pinctrl-device.yaml + +properties: + bit-waveform: + type: array + description: | + This property defines the waveform for sending 1-bit data. + The program uses the first three elements of the array. + The T0 is equal to T0H in the datasheet. + The T2 is equal to T1L in the datasheet. + The T1 is equal to (T1H-T0H) or (T0L-T1L) in the datasheet. + + Code-0 + +------+ +--- + | | | + | T0 | T1+T2 | + | | | + ---+ +-----------------+ + + Code-1 + +---------------+ +--- + | | | + | T0+T1 | T2 | + | | | + ---+ +--------+ + + + The frequency determines the wave period. + The T0～T2 means ratio in one period. + + For example, T0=3, T1=3, T2=4 and the frequency is 800kHz case, + T0H is + (1 / 800kHz) * (3/10) = 375ns + T0L is + (1 / 800kHz) * ((4+3)/10) = 875ns + +child-binding: + description: | + Worldsemi WS2812 or compatible LED strip driver based on RaspberryPi Pico's PIO + The LED strip node can put up to 4 instances under a single PIO node. + + include: ws2812.yaml + + properties: + output-pin: + type: int + required: true + description: | + Select the output pin. + + Note: This driver does not configure the output pin. + You need to configure the pin with pinctrl that is in the parent node configuration + for use by PIO. + + frequency: + type: int + description: | + Specify the number of times a waveform representing 1 bit is + transmitted per second. It is same meaning as bit-per-seconds. + WS2812 works with 800000. Set the value 400000 if use with WS2811.