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diegosueiroMaureenHelm
diegosueiro
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MaureenHelm
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drivers: add i.MX PWM driver
Adds the PWM shim driver for i.MX Signed-off-by: Diego Sueiro <[email protected]>
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‎drivers/pwm/CMakeLists.txt

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Original file line numberDiff line numberDiff line change
@@ -7,6 +7,7 @@ zephyr_library_sources_ifdef(CONFIG_PWM_STM32 pwm_stm32.c)
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zephyr_library_sources_ifdef(CONFIG_PWM_NRF5_SW pwm_nrf5_sw.c)
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zephyr_library_sources_ifdef(CONFIG_PWM_NRFX pwm_nrfx.c)
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zephyr_library_sources_ifdef(CONFIG_PWM_MCUX_FTM pwm_mcux_ftm.c)
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zephyr_library_sources_ifdef(CONFIG_PWM_IMX pwm_imx.c)
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zephyr_library_sources_ifdef(CONFIG_PWM_LED_ESP32 pwm_led_esp32.c)
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zephyr_library_sources_ifdef(CONFIG_USERSPACE pwm_handlers.c)

‎drivers/pwm/Kconfig

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Original file line numberDiff line numberDiff line change
@@ -40,6 +40,9 @@ config PWM_2
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config PWM_3
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bool "Enable PWM port 3"
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config PWM_4
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bool "Enable PWM port 4"
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source "drivers/pwm/Kconfig.pca9685"
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source "drivers/pwm/Kconfig.qmsi"
@@ -54,6 +57,8 @@ source "drivers/pwm/Kconfig.nrfx"
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source "drivers/pwm/Kconfig.mcux_ftm"
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source "drivers/pwm/Kconfig.imx"
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source "drivers/pwm/Kconfig.esp32"
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endif # PWM

‎drivers/pwm/Kconfig.imx

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@@ -0,0 +1,20 @@
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# Kconfig - i.MX PWM Config
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#
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# Copyright (c) 2018, Diego Sueiro
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#
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# SPDX-License-Identifier: Apache-2.0
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#
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menuconfig PWM_IMX
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bool
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prompt "i.MX PWM Driver"
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depends on PWM
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help
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Enable support for i.MX pwm driver.
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config PWM_PWMSWR_LOOP
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int "Loop count for PWM Software Reset"
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default 5
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depends on PWM_IMX
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help
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Loop count for PWM Software Reset when disabling PWM channel.

‎drivers/pwm/pwm_imx.c

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@@ -0,0 +1,208 @@
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/*
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* Copyright (c) 2018, Diego Sueiro <[email protected]>
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <errno.h>
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#include <pwm.h>
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#include <soc.h>
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#include <device_imx.h>
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#define SYS_LOG_LEVEL CONFIG_SYS_LOG_PWM_LEVEL
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#include <logging/sys_log.h>
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#define PWM_PWMSR_FIFOAV_4WORDS 0x4
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#define PWM_PWMCR_SWR(x) (((uint32_t)(((uint32_t)(x)) \
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<<PWM_PWMCR_SWR_SHIFT))&PWM_PWMCR_SWR_MASK)
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#define DEV_CFG(dev) \
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((const struct imx_pwm_config * const)(dev)->config->config_info)
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#define DEV_DATA(dev) \
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((struct imx_pwm_data * const)(dev)->driver_data)
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#define DEV_BASE(dev) \
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((PWM_Type *)(DEV_CFG(dev))->base)
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struct imx_pwm_config {
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PWM_Type *base;
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u16_t prescaler;
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};
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struct imx_pwm_data {
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u32_t period_cycles;
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};
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static bool imx_pwm_is_enabled(PWM_Type *base)
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{
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return PWM_PWMCR_REG(base) & PWM_PWMCR_EN_MASK;
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}
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static int imx_pwm_get_cycles_per_sec(struct device *dev, u32_t pwm,
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u64_t *cycles)
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{
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PWM_Type *base = DEV_BASE(dev);
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const struct imx_pwm_config *config = DEV_CFG(dev);
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*cycles = get_pwm_clock_freq(base) >> config->prescaler;
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return 0;
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}
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static int imx_pwm_pin_set(struct device *dev, u32_t pwm,
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u32_t period_cycles, u32_t pulse_cycles)
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{
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PWM_Type *base = DEV_BASE(dev);
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const struct imx_pwm_config *config = DEV_CFG(dev);
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struct imx_pwm_data *data = DEV_DATA(dev);
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unsigned int period_ms;
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bool enabled = imx_pwm_is_enabled(base);
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int wait_count = 0, fifoav;
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u32_t cr, sr;
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if ((period_cycles == 0) || (pulse_cycles > period_cycles)) {
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SYS_LOG_ERR("Invalid combination: period_cycles=%d, "
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"pulse_cycles=%d", period_cycles, pulse_cycles);
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return -EINVAL;
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}
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SYS_LOG_DBG("enabled=%d, pulse_cycles=%d, period_cycles=%d,"
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" duty_cycle=%d\n", enabled, pulse_cycles, period_cycles,
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(100 * pulse_cycles / period_cycles));
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/*
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* i.MX PWMv2 has a 4-word sample FIFO.
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* In order to avoid FIFO overflow issue, we do software reset
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* to clear all sample FIFO if the controller is disabled or
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* wait for a full PWM cycle to get a relinquished FIFO slot
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* when the controller is enabled and the FIFO is fully loaded.
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*/
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if (enabled) {
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sr = PWM_PWMSR_REG(base);
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fifoav = PWM_PWMSR_FIFOAV(sr);
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if (fifoav == PWM_PWMSR_FIFOAV_4WORDS) {
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period_ms = (get_pwm_clock_freq(base) >>
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config->prescaler) * MSEC_PER_SEC;
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k_sleep(K_MSEC(period_ms));
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sr = PWM_PWMSR_REG(base);
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if (fifoav == PWM_PWMSR_FIFOAV(sr)) {
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SYS_LOG_WRN("there is no free FIFO slot\n");
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}
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}
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} else {
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PWM_PWMCR_REG(base) = PWM_PWMCR_SWR(1);
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do {
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k_sleep(1);
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cr = PWM_PWMCR_REG(base);
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} while ((PWM_PWMCR_SWR(cr)) &&
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(++wait_count < CONFIG_PWM_PWMSWR_LOOP));
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if (PWM_PWMCR_SWR(cr)) {
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SYS_LOG_WRN("software reset timeout\n");
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}
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}
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/*
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* according to imx pwm RM, the real period value should be
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* PERIOD value in PWMPR plus 2.
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*/
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if (period_cycles > 2) {
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period_cycles -= 2;
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} else {
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return -EINVAL;
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}
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PWM_PWMSAR_REG(base) = pulse_cycles;
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if (data->period_cycles != period_cycles) {
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SYS_LOG_WRN("Changing period cycles from %d to %d in %s",
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data->period_cycles, period_cycles,
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dev->config->name);
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data->period_cycles = period_cycles;
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PWM_PWMPR_REG(base) = period_cycles;
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}
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cr = PWM_PWMCR_EN_MASK | PWM_PWMCR_PRESCALER(config->prescaler) |
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PWM_PWMCR_DOZEN_MASK | PWM_PWMCR_WAITEN_MASK |
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PWM_PWMCR_DBGEN_MASK | PWM_PWMCR_CLKSRC(2);
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PWM_PWMCR_REG(base) = cr;
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return 0;
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}
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static int imx_pwm_init(struct device *dev)
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{
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struct imx_pwm_data *data = DEV_DATA(dev);
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PWM_Type *base = DEV_BASE(dev);
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PWM_PWMPR_REG(base) = data->period_cycles;
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return 0;
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}
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static const struct pwm_driver_api imx_pwm_driver_api = {
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.pin_set = imx_pwm_pin_set,
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.get_cycles_per_sec = imx_pwm_get_cycles_per_sec,
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};
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#ifdef CONFIG_PWM_1
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static const struct imx_pwm_config imx_pwm_config_1 = {
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.base = (PWM_Type *)PWM_1_BASE_ADDRESS,
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.prescaler = PWM_1_PRESCALER,
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};
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static struct imx_pwm_data imx_pwm_data_1;
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DEVICE_AND_API_INIT(imx_pwm_1, PWM_1_LABEL, &imx_pwm_init,
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&imx_pwm_data_1, &imx_pwm_config_1,
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&imx_pwm_driver_api);
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#endif /* CONFIG_PWM_1 */
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#ifdef CONFIG_PWM_2
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static const struct imx_pwm_config imx_pwm_config_2 = {
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.base = (PWM_Type *)PWM_2_BASE_ADDRESS,
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.prescaler = PWM_2_PRESCALER,
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};
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static struct imx_pwm_data imx_pwm_data_2;
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DEVICE_AND_API_INIT(imx_pwm_2, PWM_2_LABEL, &imx_pwm_init,
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&imx_pwm_data_2, &imx_pwm_config_2,
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&imx_pwm_driver_api);
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#endif /* CONFIG_PWM_2 */
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#ifdef CONFIG_PWM_3
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static const struct imx_pwm_config imx_pwm_config_3 = {
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.base = (PWM_Type *)PWM_3_BASE_ADDRESS,
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.prescaler = PWM_3_PRESCALER,
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};
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static struct imx_pwm_data imx_pwm_data_3;
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DEVICE_AND_API_INIT(imx_pwm_3, PWM_3_LABEL, &imx_pwm_init,
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&imx_pwm_data_3, &imx_pwm_config_3,
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&imx_pwm_driver_api);
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#endif /* CONFIG_PWM_3 */
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#ifdef CONFIG_PWM_4
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static const struct imx_pwm_config imx_pwm_config_4 = {
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.base = (PWM_Type *)PWM_4_BASE_ADDRESS,
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.prescaler = PWM_4_PRESCALER,
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};
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static struct imx_pwm_data imx_pwm_data_4;
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DEVICE_AND_API_INIT(imx_pwm_4, PWM_4_LABEL, &imx_pwm_init,
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&imx_pwm_data_4, &imx_pwm_config_4,
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POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
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&imx_pwm_driver_api);
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#endif /* CONFIG_PWM_4 */

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