1 // SPDX-License-Identifier: GPL-2.0
6  * - The hardware supports fixed period & configures only 2-wire mode.
7  * - Supports normal polarity. Does not support changing polarity.
8  * - When PWM is disabled, output of PWM will become 0(inactive). It doesn't
9  *   keep track of running period.
10  * - When duty cycle is changed, PWM output may be a mix of previous setting
11  *   and new setting for the first period. From second period, the output is
13  * - It is a dedicated PWM fan controller. There are no other consumers for
14  *   this PWM controller.
21 #include <linux/pwm.h>
36 #define LGM_PWM_MAX_RPM			(BIT(16) - 1)
38 #define LGM_PWM_MAX_DUTY_CYCLE		(BIT(8) - 1)
47 	u32 period;  member
58 	struct regmap *regmap = pc->regmap;  in lgm_pwm_enable()
64 static int lgm_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in lgm_pwm_apply()  argument
71 	/* The hardware only supports normal polarity and fixed period. */  in lgm_pwm_apply()
72 	if (state->polarity != PWM_POLARITY_NORMAL || state->period < pc->period)  in lgm_pwm_apply()
73 		return -EINVAL;  in lgm_pwm_apply()
75 	if (!state->enabled)  in lgm_pwm_apply()
78 	duty_cycle = min_t(u64, state->duty_cycle, pc->period);  in lgm_pwm_apply()
79 	val = duty_cycle * LGM_PWM_MAX_DUTY_CYCLE / pc->period;  in lgm_pwm_apply()
81 	ret = regmap_update_bits(pc->regmap, LGM_PWM_FAN_CON0, LGM_PWM_FAN_DC_MSK,  in lgm_pwm_apply()
89 static int lgm_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,  in lgm_pwm_get_state()  argument
95 	state->enabled = regmap_test_bits(pc->regmap, LGM_PWM_FAN_CON0,  in lgm_pwm_get_state()
97 	state->polarity = PWM_POLARITY_NORMAL;  in lgm_pwm_get_state()
98 	state->period = pc->period; /* fixed period */  in lgm_pwm_get_state()
100 	regmap_read(pc->regmap, LGM_PWM_FAN_CON0, &val);  in lgm_pwm_get_state()
102 	state->duty_cycle = DIV_ROUND_UP(duty * pc->period, LGM_PWM_MAX_DUTY_CYCLE);  in lgm_pwm_get_state()
115 	struct regmap *regmap = pc->regmap;  in lgm_pwm_init()
119 	pc->period = LGM_PWM_PERIOD_2WIRE_NS;  in lgm_pwm_init()
170 	struct device *dev = &pdev->dev;  in lgm_pwm_probe()
179 		return -ENOMEM;  in lgm_pwm_probe()
185 	pc->regmap = devm_regmap_init_mmio(dev, io_base, &lgm_pwm_regmap_config);  in lgm_pwm_probe()
186 	if (IS_ERR(pc->regmap))  in lgm_pwm_probe()
187 		return dev_err_probe(dev, PTR_ERR(pc->regmap),  in lgm_pwm_probe()
207 	pc->chip.dev = dev;  in lgm_pwm_probe()
208 	pc->chip.ops = &lgm_pwm_ops;  in lgm_pwm_probe()
209 	pc->chip.npwm = 1;  in lgm_pwm_probe()
213 	ret = devm_pwmchip_add(dev, &pc->chip);  in lgm_pwm_probe()
215 		return dev_err_probe(dev, ret, "failed to add PWM chip\n");  in lgm_pwm_probe()
221 	{ .compatible = "intel,lgm-pwm" },
228 		.name = "intel-pwm",