ports/esp32/machine_bitstream.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the MicroPython project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2021 Jim Mussared
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "py/mpconfig.h"
 #include "py/mphal.h"
 #include "modesp32.h"

 #include "rom/gpio.h"
 #include "soc/gpio_reg.h"
 #include "soc/gpio_sig_map.h"

 #if MICROPY_PY_MACHINE_BITSTREAM

 /******************************************************************************/
 // Bit-bang implementation

 #define NS_TICKS_OVERHEAD (6)

 // This is a translation of the cycle counter implementation in ports/stm32/machine_bitstream.c.
 static void IRAM_ATTR machine_bitstream_high_low_bitbang(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len) {
     uint32_t pin_mask, gpio_reg_set, gpio_reg_clear;
     #if SOC_GPIO_PIN_COUNT > 32
     if (pin >= 32) {
         pin_mask = 1 << (pin - 32);
         gpio_reg_set = GPIO_OUT1_W1TS_REG;
         gpio_reg_clear = GPIO_OUT1_W1TC_REG;
     } else
     #endif
     {
         pin_mask = 1 << pin;
         gpio_reg_set = GPIO_OUT_W1TS_REG;
         gpio_reg_clear = GPIO_OUT_W1TC_REG;
     }

     // Convert ns to cpu ticks [high_time_0, period_0, high_time_1, period_1].
     uint32_t fcpu_mhz = esp_rom_get_cpu_ticks_per_us();
     for (size_t i = 0; i < 4; ++i) {
         timing_ns[i] = fcpu_mhz * timing_ns[i] / 1000;
         if (timing_ns[i] > NS_TICKS_OVERHEAD) {
             timing_ns[i] -= NS_TICKS_OVERHEAD;
         }
         if (i % 2 == 1) {
             // Convert low_time to period (i.e. add high_time).
             timing_ns[i] += timing_ns[i - 1];
         }
     }

     uint32_t irq_state = mp_hal_quiet_timing_enter();

     for (size_t i = 0; i < len; ++i) {
         uint8_t b = buf[i];
         for (size_t j = 0; j < 8; ++j) {
             GPIO_REG_WRITE(gpio_reg_set, pin_mask);
             uint32_t start_ticks = mp_hal_ticks_cpu();
             uint32_t *t = &timing_ns[b >> 6 & 2];
             while (mp_hal_ticks_cpu() - start_ticks < t[0]) {
                 ;
             }
             GPIO_REG_WRITE(gpio_reg_clear, pin_mask);
             b <<= 1;
             while (mp_hal_ticks_cpu() - start_ticks < t[1]) {
                 ;
             }
         }
     }

     mp_hal_quiet_timing_exit(irq_state);
 }

 /******************************************************************************/
 // RMT implementation

 #include "driver/rmt.h"

 // Logical 0 and 1 values (encoded as a rmt_item32_t).
 // The duration fields will be set later.
 static rmt_item32_t bitstream_high_low_0 = {{{ 0, 1, 0, 0 }}};
 static rmt_item32_t bitstream_high_low_1 = {{{ 0, 1, 0, 0 }}};

 // See https://github.com/espressif/esp-idf/blob/master/examples/common_components/led_strip/led_strip_rmt_ws2812.c
 // This is called automatically by the IDF during rmt_write_sample in order to
 // convert the byte stream to rmt_item32_t's.
 static void IRAM_ATTR bitstream_high_low_rmt_adapter(const void *src, rmt_item32_t *dest, size_t src_size, size_t wanted_num, size_t *translated_size, size_t *item_num) {
     if (src == NULL || dest == NULL) {
         *translated_size = 0;
         *item_num = 0;
         return;
     }

     size_t size = 0;
     size_t num = 0;
     uint8_t *psrc = (uint8_t *)src;
     rmt_item32_t *pdest = dest;
     while (size < src_size && num < wanted_num) {
         for (int i = 0; i < 8; i++) {
             // MSB first
             if (*psrc & (1 << (7 - i))) {
                 pdest->val = bitstream_high_low_1.val;
             } else {
                 pdest->val = bitstream_high_low_0.val;
             }
             num++;
             pdest++;
         }
         size++;
         psrc++;
     }

     *translated_size = size;
     *item_num = num;
 }

 // Use the reserved RMT channel to stream high/low data on the specified pin.
 static void machine_bitstream_high_low_rmt(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len, uint8_t channel_id) {
     rmt_config_t config = RMT_DEFAULT_CONFIG_TX(pin, channel_id);

     // Use 40MHz clock (although 2MHz would probably be sufficient).
     config.clk_div = 2;

     // Install the driver on this channel & pin.
     check_esp_err(rmt_config(&config));
     check_esp_err(rmt_driver_install_core1(config.channel));

     // Get the tick rate in kHz (this will likely be 40000).
     uint32_t counter_clk_khz = 0;
     check_esp_err(rmt_get_counter_clock(config.channel, &counter_clk_khz));

     counter_clk_khz /= 1000;

     // Convert nanoseconds to pulse duration.
     bitstream_high_low_0.duration0 = (counter_clk_khz * timing_ns[0]) / 1e6;
     bitstream_high_low_0.duration1 = (counter_clk_khz * timing_ns[1]) / 1e6;
     bitstream_high_low_1.duration0 = (counter_clk_khz * timing_ns[2]) / 1e6;
     bitstream_high_low_1.duration1 = (counter_clk_khz * timing_ns[3]) / 1e6;

     // Install the bits->highlow translator.
     rmt_translator_init(config.channel, bitstream_high_low_rmt_adapter);

     // Stream the byte data using the translator.
     check_esp_err(rmt_write_sample(config.channel, buf, len, true));

     // Wait 50% longer than we expect (if every bit takes the maximum time).
     uint32_t timeout_ms = (3 * len / 2) * (1 + (8 * MAX(timing_ns[0] + timing_ns[1], timing_ns[2] + timing_ns[3])) / 1000);
     check_esp_err(rmt_wait_tx_done(config.channel, pdMS_TO_TICKS(timeout_ms)));

     // Uninstall the driver.
     check_esp_err(rmt_driver_uninstall(config.channel));

     // Cancel RMT output to GPIO pin.
     esp_rom_gpio_connect_out_signal(pin, SIG_GPIO_OUT_IDX, false, false);
 }

 /******************************************************************************/
 // Interface to machine.bitstream

 void machine_bitstream_high_low(mp_hal_pin_obj_t pin, uint32_t *timing_ns, const uint8_t *buf, size_t len) {
     if (esp32_rmt_bitstream_channel_id < 0) {
         machine_bitstream_high_low_bitbang(pin, timing_ns, buf, len);
     } else {
         machine_bitstream_high_low_rmt(pin, timing_ns, buf, len, esp32_rmt_bitstream_channel_id);
     }
 }

 #endif // MICROPY_PY_MACHINE_BITSTREAM
	/*
	* This file is part of the MicroPython project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2021 Jim Mussared
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "py/mpconfig.h"
	#include "py/mphal.h"
	#include "modesp32.h"

	#include "rom/gpio.h"
	#include "soc/gpio_reg.h"
	#include "soc/gpio_sig_map.h"

	#if MICROPY_PY_MACHINE_BITSTREAM

	/******************************************************************************/
	// Bit-bang implementation

	#define NS_TICKS_OVERHEAD (6)

	// This is a translation of the cycle counter implementation in ports/stm32/machine_bitstream.c.
	static void IRAM_ATTR machine_bitstream_high_low_bitbang(mp_hal_pin_obj_t pin, uint32_t timing_ns, const uint8_t buf, size_t len) {
	uint32_t pin_mask, gpio_reg_set, gpio_reg_clear;
	#if SOC_GPIO_PIN_COUNT > 32
	if (pin >= 32) {
	pin_mask = 1 << (pin - 32);
	gpio_reg_set = GPIO_OUT1_W1TS_REG;
	gpio_reg_clear = GPIO_OUT1_W1TC_REG;
	} else
	#endif
	{
	pin_mask = 1 << pin;
	gpio_reg_set = GPIO_OUT_W1TS_REG;
	gpio_reg_clear = GPIO_OUT_W1TC_REG;
	}

	// Convert ns to cpu ticks [high_time_0, period_0, high_time_1, period_1].
	uint32_t fcpu_mhz = esp_rom_get_cpu_ticks_per_us();
	for (size_t i = 0; i < 4; ++i) {
	timing_ns[i] = fcpu_mhz * timing_ns[i] / 1000;
	if (timing_ns[i] > NS_TICKS_OVERHEAD) {
	timing_ns[i] -= NS_TICKS_OVERHEAD;
	}
	if (i % 2 == 1) {
	// Convert low_time to period (i.e. add high_time).
	timing_ns[i] += timing_ns[i - 1];
	}
	}

	uint32_t irq_state = mp_hal_quiet_timing_enter();

	for (size_t i = 0; i < len; ++i) {
	uint8_t b = buf[i];
	for (size_t j = 0; j < 8; ++j) {
	GPIO_REG_WRITE(gpio_reg_set, pin_mask);
	uint32_t start_ticks = mp_hal_ticks_cpu();
	uint32_t *t = &timing_ns[b >> 6 & 2];
	while (mp_hal_ticks_cpu() - start_ticks < t[0]) {
	;
	}
	GPIO_REG_WRITE(gpio_reg_clear, pin_mask);
	b <<= 1;
	while (mp_hal_ticks_cpu() - start_ticks < t[1]) {
	;
	}
	}
	}

	mp_hal_quiet_timing_exit(irq_state);
	}

	/******************************************************************************/
	// RMT implementation

	#include "driver/rmt.h"

	// Logical 0 and 1 values (encoded as a rmt_item32_t).
	// The duration fields will be set later.
	static rmt_item32_t bitstream_high_low_0 = {{{ 0, 1, 0, 0 }}};
	static rmt_item32_t bitstream_high_low_1 = {{{ 0, 1, 0, 0 }}};

	// See https://github.com/espressif/esp-idf/blob/master/examples/common_components/led_strip/led_strip_rmt_ws2812.c
	// This is called automatically by the IDF during rmt_write_sample in order to
	// convert the byte stream to rmt_item32_t's.
	static void IRAM_ATTR bitstream_high_low_rmt_adapter(const void src, rmt_item32_t dest, size_t src_size, size_t wanted_num, size_t translated_size, size_t item_num) {
	if (src == NULL \|\| dest == NULL) {
	*translated_size = 0;
	*item_num = 0;
	return;
	}

	size_t size = 0;
	size_t num = 0;
	uint8_t psrc = (uint8_t )src;
	rmt_item32_t *pdest = dest;
	while (size < src_size && num < wanted_num) {
	for (int i = 0; i < 8; i++) {
	// MSB first
	if (*psrc & (1 << (7 - i))) {
	pdest->val = bitstream_high_low_1.val;
	} else {
	pdest->val = bitstream_high_low_0.val;
	}
	num++;
	pdest++;
	}
	size++;
	psrc++;
	}

	*translated_size = size;
	*item_num = num;
	}

	// Use the reserved RMT channel to stream high/low data on the specified pin.
	static void machine_bitstream_high_low_rmt(mp_hal_pin_obj_t pin, uint32_t timing_ns, const uint8_t buf, size_t len, uint8_t channel_id) {
	rmt_config_t config = RMT_DEFAULT_CONFIG_TX(pin, channel_id);

	// Use 40MHz clock (although 2MHz would probably be sufficient).
	config.clk_div = 2;

	// Install the driver on this channel & pin.
	check_esp_err(rmt_config(&config));
	check_esp_err(rmt_driver_install_core1(config.channel));

	// Get the tick rate in kHz (this will likely be 40000).
	uint32_t counter_clk_khz = 0;
	check_esp_err(rmt_get_counter_clock(config.channel, &counter_clk_khz));

	counter_clk_khz /= 1000;

	// Convert nanoseconds to pulse duration.
	bitstream_high_low_0.duration0 = (counter_clk_khz * timing_ns[0]) / 1e6;
	bitstream_high_low_0.duration1 = (counter_clk_khz * timing_ns[1]) / 1e6;
	bitstream_high_low_1.duration0 = (counter_clk_khz * timing_ns[2]) / 1e6;
	bitstream_high_low_1.duration1 = (counter_clk_khz * timing_ns[3]) / 1e6;

	// Install the bits->highlow translator.
	rmt_translator_init(config.channel, bitstream_high_low_rmt_adapter);

	// Stream the byte data using the translator.
	check_esp_err(rmt_write_sample(config.channel, buf, len, true));

	// Wait 50% longer than we expect (if every bit takes the maximum time).
	uint32_t timeout_ms = (3 * len / 2) * (1 + (8 * MAX(timing_ns[0] + timing_ns[1], timing_ns[2] + timing_ns[3])) / 1000);
	check_esp_err(rmt_wait_tx_done(config.channel, pdMS_TO_TICKS(timeout_ms)));

	// Uninstall the driver.
	check_esp_err(rmt_driver_uninstall(config.channel));

	// Cancel RMT output to GPIO pin.
	esp_rom_gpio_connect_out_signal(pin, SIG_GPIO_OUT_IDX, false, false);
	}

	/******************************************************************************/
	// Interface to machine.bitstream

	void machine_bitstream_high_low(mp_hal_pin_obj_t pin, uint32_t timing_ns, const uint8_t buf, size_t len) {
	if (esp32_rmt_bitstream_channel_id < 0) {
	machine_bitstream_high_low_bitbang(pin, timing_ns, buf, len);
	} else {
	machine_bitstream_high_low_rmt(pin, timing_ns, buf, len, esp32_rmt_bitstream_channel_id);
	}
	}

	#endif // MICROPY_PY_MACHINE_BITSTREAM