drivers: pwm: initial device driver for ENE KB1200

Add pwm driver for ENE KB1200

Signed-off-by: Steven Chang <[email protected]>

Author: ene-steven

drivers/pwm/CMakeLists.txt

@@ -40,6 +40,7 @@ zephyr_library_sources_ifdef(CONFIG_PWM_XMC4XXX_CCU8	pwm_xmc4xxx_ccu8.c)
 zephyr_library_sources_ifdef(CONFIG_PWM_MCUX_CTIMER	pwm_mcux_ctimer.c)
 zephyr_library_sources_ifdef(CONFIG_PWM_NUMAKER		pwm_numaker.c)
 zephyr_library_sources_ifdef(CONFIG_PWM_NXP_S32_EMIOS pwm_nxp_s32_emios.c)
+zephyr_library_sources_ifdef(CONFIG_PWM_ENE_KB1200	pwm_ene_kb1200.c)
 
 zephyr_library_sources_ifdef(CONFIG_USERSPACE   pwm_handlers.c)
 zephyr_library_sources_ifdef(CONFIG_PWM_CAPTURE pwm_capture.c)

drivers/pwm/Kconfig

@@ -100,4 +100,6 @@ source "drivers/pwm/Kconfig.numaker"
 
 source "drivers/pwm/Kconfig.nxp_s32_emios"
 
+source "drivers/pwm/Kconfig.ene"
+
 endif # PWM

drivers/pwm/Kconfig.ene

@@ -0,0 +1,10 @@
+# Copyright (c) 2024 ENE Technology Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config PWM_ENE_KB1200
+	bool "ENE KB1200 PWM driver"
+	default y
+	depends on DT_HAS_ENE_KB1200_PWM_ENABLED
+	select PINCTRL
+	help
+	  This option enables the PWM driver for KB1200 processors.

drivers/pwm/pwm_ene_kb1200.c

@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2024 ENE Technology Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT ene_kb1200_pwm
+
+#include <zephyr/drivers/pwm.h>
+#include <zephyr/drivers/pinctrl.h>
+#include <reg/pwm.h>
+
+/* Device config */
+struct pwm_kb1200_config {
+	/* pwm controller base address */
+	struct pwm_regs *pwm;
+	const struct pinctrl_dev_config *pcfg;
+};
+
+/* Driver data */
+struct pwm_kb1200_data {
+	/* PWM cycles per second */
+	uint32_t cycles_per_sec;
+};
+
+/* PWM api functions */
+static int pwm_kb1200_set_cycles(const struct device *dev, uint32_t channel, uint32_t period_cycles,
+				 uint32_t pulse_cycles, pwm_flags_t flags)
+{
+	/* Single channel for each pwm device */
+	ARG_UNUSED(channel);
+	const struct pwm_kb1200_config *config = dev->config;
+	int prescaler;
+	uint32_t high_len;
+	uint32_t cycle_len;
+
+	/*
+	 * Calculate PWM prescaler that let period_cycles map to
+	 * maximum pwm period cycles and won't exceed it.
+	 * Then prescaler = ceil (period_cycles / pwm_max_period_cycles)
+	 */
+	prescaler = DIV_ROUND_UP(period_cycles, PWM_MAX_CYCLES);
+	if (prescaler > PWM_MAX_PRESCALER) {
+		return -EINVAL;
+	}
+
+	/* If pulse_cycles is 0, switch PWM off and return. */
+	if (pulse_cycles == 0) {
+		config->pwm->PWMCFG &= ~PWM_ENABLE;
+		return 0;
+	}
+
+	high_len = (pulse_cycles / prescaler);
+	cycle_len = (period_cycles / prescaler);
+
+	/* Select PWM inverted polarity (ie. active-low pulse). */
+	if (flags & PWM_POLARITY_INVERTED) {
+		high_len = cycle_len - high_len;
+	}
+
+	/* Set PWM prescaler. */
+	config->pwm->PWMCFG = (config->pwm->PWMCFG & ~GENMASK(13, 8)) | ((prescaler - 1) << 8);
+
+	/*
+	 * period_cycles: PWM Cycle Length
+	 * pulse_cycles : PWM High Length
+	 */
+	config->pwm->PWMHIGH = high_len;
+	config->pwm->PWMCYC = cycle_len;
+
+	/* Start pwm */
+	config->pwm->PWMCFG |= PWM_ENABLE;
+
+	return 0;
+}
+
+static int pwm_kb1200_get_cycles_per_sec(const struct device *dev, uint32_t channel,
+					 uint64_t *cycles)
+{
+	/* Single channel for each pwm device */
+	ARG_UNUSED(channel);
+	ARG_UNUSED(dev);
+
+	if (cycles) {
+		/* User does not have to know about lowest clock,
+		 * the driver will select the most relevant one.
+		 */
+		*cycles = PWM_INPUT_FREQ_HI; /*32Mhz*/
+	}
+	return 0;
+}
+
+static const struct pwm_driver_api pwm_kb1200_driver_api = {
+	.set_cycles = pwm_kb1200_set_cycles,
+	.get_cycles_per_sec = pwm_kb1200_get_cycles_per_sec,
+};
+
+static int pwm_kb1200_init(const struct device *dev)
+{
+	int ret;
+	const struct pwm_kb1200_config *config = dev->config;
+
+	ret = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
+	if (ret != 0) {
+		return ret;
+	}
+	config->pwm->PWMCFG = PWM_SOURCE_CLK_32M | PWM_RULE1 | PWM_PUSHPULL;
+
+	return 0;
+}
+
+#define KB1200_PWM_INIT(inst)                                                                      \
+	PINCTRL_DT_INST_DEFINE(inst);                                                              \
+	static const struct pwm_kb1200_config pwm_kb1200_cfg_##inst = {                            \
+		.pwm = (struct pwm_regs *)DT_INST_REG_ADDR(inst),                                  \
+		.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst),                                      \
+	};                                                                                         \
+	static struct pwm_kb1200_data pwm_kb1200_data_##inst;                                      \
+	DEVICE_DT_INST_DEFINE(inst, &pwm_kb1200_init, NULL, &pwm_kb1200_data_##inst,               \
+			      &pwm_kb1200_cfg_##inst, PRE_KERNEL_1, CONFIG_PWM_INIT_PRIORITY,      \
+			      &pwm_kb1200_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(KB1200_PWM_INIT)