4  * SPDX-License-Identifier: Apache-2.0
10 #include <zephyr/drivers/pwm.h>
11 #include <zephyr/dt-bindings/clock/npcx_clock.h>
20 /* 16-bit period cycles/prescaler in NPCX PWM modules */
24 /* PWM clock sources */
30 /* PWM heart-beat mode selection */
38 	/* pwm controller base address */
40 	/* clock configuration */
48 	/* PWM cycles per second */
52 /* PWM local functions */
55 	const struct pwm_npcx_config *config = dev->config;  in pwm_npcx_configure()
56 	struct pwm_reg *inst = config->base;  in pwm_npcx_configure()
58 	/* Disable PWM for module configuration first */  in pwm_npcx_configure()
59 	inst->PWMCTL &= ~BIT(NPCX_PWMCTL_PWR);  in pwm_npcx_configure()
61 	/* Set default PWM polarity to normal */  in pwm_npcx_configure()
62 	inst->PWMCTL &= ~BIT(NPCX_PWMCTL_INVP);  in pwm_npcx_configure()
64 	/* Turn off PWM heart-beat mode */  in pwm_npcx_configure()
65 	SET_FIELD(inst->PWMCTL, NPCX_PWMCTL_HB_DC_CTL_FIELD,  in pwm_npcx_configure()
68 	/* Select APB CLK/LFCLK clock sources to PWM module by default */  in pwm_npcx_configure()
69 	SET_FIELD(inst->PWMCTLEX, NPCX_PWMCTLEX_FCK_SEL_FIELD,  in pwm_npcx_configure()
72 	/* Select clock source to LFCLK by flag, otherwise APB clock source */  in pwm_npcx_configure()
74 		inst->PWMCTL |= BIT(NPCX_PWMCTL_CKSEL);  in pwm_npcx_configure()
76 		inst->PWMCTL &= ~BIT(NPCX_PWMCTL_CKSEL);  in pwm_npcx_configure()
80 /* PWM api functions */
85 	/* Single channel for each pwm device */  in pwm_npcx_set_cycles()
87 	const struct pwm_npcx_config *config = dev->config;  in pwm_npcx_set_cycles()
88 	struct pwm_npcx_data *const data = dev->data;  in pwm_npcx_set_cycles()
89 	struct pwm_reg *inst = config->base;  in pwm_npcx_set_cycles()
96 	ctl = inst->PWMCTL | BIT(NPCX_PWMCTL_PWR);  in pwm_npcx_set_cycles()
98 	/* Select PWM inverted polarity (ie. active-low pulse). */  in pwm_npcx_set_cycles()
105 	/* If pulse_cycles is 0, switch PWM off and return. */  in pwm_npcx_set_cycles()
108 		inst->PWMCTL = ctl;  in pwm_npcx_set_cycles()
113 	 * Calculate PWM prescaler that let period_cycles map to  in pwm_npcx_set_cycles()
114 	 * maximum pwm period cycles and won't exceed it.  in pwm_npcx_set_cycles()
119 		return -EINVAL;  in pwm_npcx_set_cycles()
122 	/* Set PWM prescaler. */  in pwm_npcx_set_cycles()
123 	prsc = prescaler - 1;  in pwm_npcx_set_cycles()
125 	/* Set PWM period cycles. */  in pwm_npcx_set_cycles()
126 	ctr = (period_cycles / prescaler) - 1;  in pwm_npcx_set_cycles()
128 	/* Set PWM pulse cycles. */  in pwm_npcx_set_cycles()
129 	dcr = (pulse_cycles / prescaler) - 1;  in pwm_npcx_set_cycles()
132 		data->cycles_per_sec / period_cycles, prsc, ctr, dcr);  in pwm_npcx_set_cycles()
135 	if (inst->PWMCTL != ctl || inst->PRSC != prsc || inst->CTR != ctr) {  in pwm_npcx_set_cycles()
136 		/* Disable PWM before configuring. */  in pwm_npcx_set_cycles()
137 		inst->PWMCTL &= ~BIT(NPCX_PWMCTL_PWR);  in pwm_npcx_set_cycles()
139 		inst->PRSC = prsc;  in pwm_npcx_set_cycles()
140 		inst->CTR = ctr;  in pwm_npcx_set_cycles()
141 		inst->DCR = dcr;  in pwm_npcx_set_cycles()
143 		/* Enable PWM now. */  in pwm_npcx_set_cycles()
144 		inst->PWMCTL = ctl;  in pwm_npcx_set_cycles()
149 	inst->DCR = dcr;  in pwm_npcx_set_cycles()
157 	/* Single channel for each pwm device */  in pwm_npcx_get_cycles_per_sec()
159 	struct pwm_npcx_data *const data = dev->data;  in pwm_npcx_get_cycles_per_sec()
161 	*cycles = data->cycles_per_sec;  in pwm_npcx_get_cycles_per_sec()
165 /* PWM driver registration */
166 static DEVICE_API(pwm, pwm_npcx_driver_api) = {
173 	const struct pwm_npcx_config *const config = dev->config;  in pwm_npcx_init()
174 	struct pwm_npcx_data *const data = dev->data;  in pwm_npcx_init()
175 	struct pwm_reg *const inst = config->base;  in pwm_npcx_init()
180 	 * NPCX PWM module mixes byte and word registers together. Make sure  in pwm_npcx_init()
184 	NPCX_REG_WORD_ACCESS_CHECK(inst->PRSC, 0xA55A);  in pwm_npcx_init()
188 		LOG_ERR("clock control device not ready");  in pwm_npcx_init()
189 		return -ENODEV;  in pwm_npcx_init()
192 	/* Turn on device clock first and get source clock freq. */  in pwm_npcx_init()
194 							&config->clk_cfg);  in pwm_npcx_init()
196 		LOG_ERR("Turn on PWM clock fail %d", ret);  in pwm_npcx_init()
201 			&config->clk_cfg, &data->cycles_per_sec);  in pwm_npcx_init()
203 		LOG_ERR("Get PWM clock rate error %d", ret);  in pwm_npcx_init()
207 	/* Configure PWM device initially */  in pwm_npcx_init()
208 	pwm_npcx_configure(dev, config->clk_cfg.bus);  in pwm_npcx_init()
210 	/* Configure pin-mux for PWM device */  in pwm_npcx_init()
211 	ret = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);  in pwm_npcx_init()
213 		LOG_ERR("PWM pinctrl setup failed (%d)", ret);  in pwm_npcx_init()