1 // SPDX-License-Identifier: GPL-2.0
3  * Expose a PWM controlled by the ChromeOS EC to the host processor.
12 #include <linux/pwm.h>
16  * struct cros_ec_pwm_device - Driver data for EC PWM
20  * @chip: PWM controller chip
29  * struct cros_ec_pwm - per-PWM driver data
41 static int cros_ec_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)  in cros_ec_pwm_request()  argument
47 		return -ENOMEM;  in cros_ec_pwm_request()
49 	pwm_set_chip_data(pwm, channel);  in cros_ec_pwm_request()
54 static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)  in cros_ec_pwm_free()  argument
56 	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);  in cros_ec_pwm_free()
72 	msg->version = 0;  in cros_ec_pwm_set_duty()
73 	msg->command = EC_CMD_PWM_SET_DUTY;  in cros_ec_pwm_set_duty()
74 	msg->insize = 0;  in cros_ec_pwm_set_duty()
75 	msg->outsize = sizeof(*params);  in cros_ec_pwm_set_duty()
77 	params->duty = duty;  in cros_ec_pwm_set_duty()
78 	params->pwm_type = EC_PWM_TYPE_GENERIC;  in cros_ec_pwm_set_duty()
79 	params->index = index;  in cros_ec_pwm_set_duty()
100 	msg->version = 0;  in cros_ec_pwm_get_duty()
101 	msg->command = EC_CMD_PWM_GET_DUTY;  in cros_ec_pwm_get_duty()
102 	msg->insize = sizeof(*resp);  in cros_ec_pwm_get_duty()
103 	msg->outsize = sizeof(*params);  in cros_ec_pwm_get_duty()
105 	params->pwm_type = EC_PWM_TYPE_GENERIC;  in cros_ec_pwm_get_duty()
106 	params->index = index;  in cros_ec_pwm_get_duty()
112 	return resp->duty;  in cros_ec_pwm_get_duty()
115 static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in cros_ec_pwm_apply()  argument
119 	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);  in cros_ec_pwm_apply()
124 	if (state->period != EC_PWM_MAX_DUTY)  in cros_ec_pwm_apply()
125 		return -EINVAL;  in cros_ec_pwm_apply()
131 	duty_cycle = state->enabled ? state->duty_cycle : 0;  in cros_ec_pwm_apply()
133 	ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);  in cros_ec_pwm_apply()
137 	channel->duty_cycle = state->duty_cycle;  in cros_ec_pwm_apply()
142 static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,  in cros_ec_pwm_get_state()  argument
146 	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);  in cros_ec_pwm_get_state()
149 	ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm);  in cros_ec_pwm_get_state()
151 		dev_err(chip->dev, "error getting initial duty: %d\n", ret);  in cros_ec_pwm_get_state()
155 	state->enabled = (ret > 0);  in cros_ec_pwm_get_state()
156 	state->period = EC_PWM_MAX_DUTY;  in cros_ec_pwm_get_state()
164 	 * For the case of the initial hardware readout, channel->duty_cycle  in cros_ec_pwm_get_state()
167 	if (ret == 0 && channel->duty_cycle > 0)  in cros_ec_pwm_get_state()
168 		state->duty_cycle = channel->duty_cycle;  in cros_ec_pwm_get_state()
170 		state->duty_cycle = ret;  in cros_ec_pwm_get_state()
176 	struct pwm_device *pwm;  in cros_ec_pwm_xlate()  local
178 	if (args->args[0] >= pc->npwm)  in cros_ec_pwm_xlate()
179 		return ERR_PTR(-EINVAL);  in cros_ec_pwm_xlate()
181 	pwm = pwm_request_from_chip(pc, args->args[0], NULL);  in cros_ec_pwm_xlate()
182 	if (IS_ERR(pwm))  in cros_ec_pwm_xlate()
183 		return pwm;  in cros_ec_pwm_xlate()
186 	pwm->args.period = EC_PWM_MAX_DUTY;  in cros_ec_pwm_xlate()
188 	return pwm;  in cros_ec_pwm_xlate()
200  * Determine the number of supported PWMs. The EC does not return the number
201  * of PWMs it supports directly, so we have to read the pwm duty cycle for
214 		 * The EC error codes map to -EOPNOTSUPP and -EINVAL,  in cros_ec_num_pwms()
218 		case -EOPNOTSUPP:	/* invalid command */  in cros_ec_num_pwms()
219 			return -ENODEV;  in cros_ec_num_pwms()
220 		case -EINVAL:		/* invalid parameter */  in cros_ec_num_pwms()
234 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);  in cros_ec_pwm_probe()
235 	struct device *dev = &pdev->dev;  in cros_ec_pwm_probe()
242 		return -EINVAL;  in cros_ec_pwm_probe()
247 		return -ENOMEM;  in cros_ec_pwm_probe()
248 	chip = &ec_pwm->chip;  in cros_ec_pwm_probe()
249 	ec_pwm->ec = ec;  in cros_ec_pwm_probe()
251 	/* PWM chip */  in cros_ec_pwm_probe()
252 	chip->dev = dev;  in cros_ec_pwm_probe()
253 	chip->ops = &cros_ec_pwm_ops;  in cros_ec_pwm_probe()
254 	chip->of_xlate = cros_ec_pwm_xlate;  in cros_ec_pwm_probe()
255 	chip->of_pwm_n_cells = 1;  in cros_ec_pwm_probe()
256 	chip->base = -1;  in cros_ec_pwm_probe()
262 	chip->npwm = ret;  in cros_ec_pwm_probe()
263 	dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);  in cros_ec_pwm_probe()
267 		dev_err(dev, "cannot register PWM: %d\n", ret);  in cros_ec_pwm_probe()
279 	struct pwm_chip *chip = &ec_pwm->chip;  in cros_ec_pwm_remove()
286 	{ .compatible = "google,cros-ec-pwm" },
296 		.name = "cros-ec-pwm",
302 MODULE_ALIAS("platform:cros-ec-pwm");
303 MODULE_DESCRIPTION("ChromeOS EC PWM driver");