From b589355a108f1d576912a7d70d6a1d6690703c2a Mon Sep 17 00:00:00 2001
From: morris <maoshengrong@espressif.com>
Date: Wed, 19 Jul 2023 11:27:11 +0800
Subject: [PATCH] feat(mcpwm): support open drain output for generator IO

Closes https://github.com/espressif/esp-idf/issues/11877
---
 components/driver/mcpwm/include/driver/mcpwm_gen.h | 1 +
 components/driver/mcpwm/mcpwm_gen.c                | 3 ++-
 components/driver/rmt/rmt_tx.c                     | 2 +-
 docs/en/api-reference/peripherals/mcpwm.rst        | 2 ++
 docs/zh_CN/api-reference/peripherals/mcpwm.rst     | 2 ++
 5 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/components/driver/mcpwm/include/driver/mcpwm_gen.h b/components/driver/mcpwm/include/driver/mcpwm_gen.h
index f070146dd6..91d46ce702 100644
--- a/components/driver/mcpwm/include/driver/mcpwm_gen.h
+++ b/components/driver/mcpwm/include/driver/mcpwm_gen.h
@@ -24,6 +24,7 @@ typedef struct {
     struct {
         uint32_t invert_pwm: 1;   /*!< Whether to invert the PWM signal (done by GPIO matrix) */
         uint32_t io_loop_back: 1; /*!< For debug/test, the signal output from the GPIO will be fed to the input path as well */
+        uint32_t io_od_mode: 1;   /*!< Configure the GPIO as open-drain mode */
         uint32_t pull_up: 1;      /*!< Whether to pull up internally */
         uint32_t pull_down: 1;    /*!< Whether to pull down internally */
     } flags;                      /*!< Extra configuration flags for generator */
diff --git a/components/driver/mcpwm/mcpwm_gen.c b/components/driver/mcpwm/mcpwm_gen.c
index b394ab2602..6c2e049d52 100644
--- a/components/driver/mcpwm/mcpwm_gen.c
+++ b/components/driver/mcpwm/mcpwm_gen.c
@@ -86,7 +86,8 @@ esp_err_t mcpwm_new_generator(mcpwm_oper_handle_t oper, const mcpwm_generator_co
     // GPIO configuration
     gpio_config_t gpio_conf = {
         .intr_type = GPIO_INTR_DISABLE,
-        .mode = GPIO_MODE_OUTPUT | (config->flags.io_loop_back ? GPIO_MODE_INPUT : 0), // also enable the input path if `io_loop_back` is enabled
+        // also enable the input path if `io_loop_back` is enabled
+        .mode = (config->flags.io_od_mode ? GPIO_MODE_OUTPUT_OD : GPIO_MODE_OUTPUT) | (config->flags.io_loop_back ? GPIO_MODE_INPUT : 0),
         .pin_bit_mask = (1ULL << config->gen_gpio_num),
         .pull_down_en = config->flags.pull_down,
         .pull_up_en = config->flags.pull_up,
diff --git a/components/driver/rmt/rmt_tx.c b/components/driver/rmt/rmt_tx.c
index 6a0766e22d..d4b7cf21a2 100644
--- a/components/driver/rmt/rmt_tx.c
+++ b/components/driver/rmt/rmt_tx.c
@@ -277,7 +277,7 @@ esp_err_t rmt_new_tx_channel(const rmt_tx_channel_config_t *config, rmt_channel_
     tx_channel->base.gpio_num = config->gpio_num;
     gpio_config_t gpio_conf = {
         .intr_type = GPIO_INTR_DISABLE,
-        // also enable the input path is `io_loop_back` is on, this is useful for bi-directional buses
+        // also enable the input path if `io_loop_back` is on, this is useful for bi-directional buses
         .mode = (config->flags.io_od_mode ? GPIO_MODE_OUTPUT_OD : GPIO_MODE_OUTPUT) | (config->flags.io_loop_back ? GPIO_MODE_INPUT : 0),
         .pull_down_en = false,
         .pull_up_en = true,
diff --git a/docs/en/api-reference/peripherals/mcpwm.rst b/docs/en/api-reference/peripherals/mcpwm.rst
index 112909a68c..ad7738051c 100644
--- a/docs/en/api-reference/peripherals/mcpwm.rst
+++ b/docs/en/api-reference/peripherals/mcpwm.rst
@@ -114,6 +114,8 @@ You can allocate a MCPWM generator object by calling the :cpp:func:`mcpwm_new_ge
 - :cpp:member:`mcpwm_generator_config_t::gen_gpio_num` sets the GPIO number used by the generator.
 - :cpp:member:`mcpwm_generator_config_t::invert_pwm` sets whether to invert the PWM signal.
 - :cpp:member:`mcpwm_generator_config_t::io_loop_back` sets whether to enable the Loop-back mode. It is for debugging purposes only. It enables both the GPIO's input and output ability through the GPIO matrix peripheral.
+- :cpp:member:`mcpwm_generator_config_t::io_od_mode` configures the PWM GPIO as open-drain output.
+- :cpp:member:`mcpwm_generator_config_t::pull_up` and :cpp:member:`mcpwm_generator_config_t::pull_down` controls whether to enable the internal pull-up and pull-down resistors accordingly.
 
 The :cpp:func:`mcpwm_new_generator` will return a pointer to the allocated generator object if the allocation succeeds. Otherwise, it will return an error code. Specifically, when there are no more free generators in the MCPWM operator, this function will return the :c:macro:`ESP_ERR_NOT_FOUND` error. [1]_
 
diff --git a/docs/zh_CN/api-reference/peripherals/mcpwm.rst b/docs/zh_CN/api-reference/peripherals/mcpwm.rst
index 478d193535..8bd775853b 100644
--- a/docs/zh_CN/api-reference/peripherals/mcpwm.rst
+++ b/docs/zh_CN/api-reference/peripherals/mcpwm.rst
@@ -114,6 +114,8 @@ MCPWM 生成器
 - :cpp:member:`mcpwm_generator_config_t::gen_gpio_num` 设置生成器使用的 GPIO 编号。
 - :cpp:member:`mcpwm_generator_config_t::invert_pwm` 设置是否反相 PWM 信号。
 - :cpp:member:`mcpwm_generator_config_t::io_loop_back` 设置是否启用回环模式。该模式仅用于调试，使用 GPIO 交换矩阵外设同时启用 GPIO 输入和输出。
+- :cpp:member:`mcpwm_generator_config_t::io_od_mode` 设置是否启用漏极开路输出。
+- :cpp:member:`mcpwm_generator_config_t::pull_up` 和 :cpp:member:`mcpwm_generator_config_t::pull_down` 用来设置是否启用内部上下拉电阻。
 
 分配成功后，:cpp:func:`mcpwm_new_generator` 将返回一个指向已分配生成器的指针。否则，函数将返回错误代码。具体来说，当 MCPWM 操作器中没有空闲生成器时，将返回 :c:macro:`ESP_ERR_NOT_FOUND` 错误。[1]_