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()
127 	if (state->polarity != PWM_POLARITY_NORMAL)  in cros_ec_pwm_apply()
128 		return -EINVAL;  in cros_ec_pwm_apply()
134 	duty_cycle = state->enabled ? state->duty_cycle : 0;  in cros_ec_pwm_apply()
136 	ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle);  in cros_ec_pwm_apply()
140 	channel->duty_cycle = state->duty_cycle;  in cros_ec_pwm_apply()
145 static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,  in cros_ec_pwm_get_state()  argument
149 	struct cros_ec_pwm *channel = pwm_get_chip_data(pwm);  in cros_ec_pwm_get_state()
152 	ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm);  in cros_ec_pwm_get_state()
154 		dev_err(chip->dev, "error getting initial duty: %d\n", ret);  in cros_ec_pwm_get_state()
158 	state->enabled = (ret > 0);  in cros_ec_pwm_get_state()
159 	state->period = EC_PWM_MAX_DUTY;  in cros_ec_pwm_get_state()
167 	 * For the case of the initial hardware readout, channel->duty_cycle  in cros_ec_pwm_get_state()
170 	if (ret == 0 && channel->duty_cycle > 0)  in cros_ec_pwm_get_state()
171 		state->duty_cycle = channel->duty_cycle;  in cros_ec_pwm_get_state()
173 		state->duty_cycle = ret;  in cros_ec_pwm_get_state()
179 	struct pwm_device *pwm;  in cros_ec_pwm_xlate()  local
181 	if (args->args[0] >= pc->npwm)  in cros_ec_pwm_xlate()
182 		return ERR_PTR(-EINVAL);  in cros_ec_pwm_xlate()
184 	pwm = pwm_request_from_chip(pc, args->args[0], NULL);  in cros_ec_pwm_xlate()
185 	if (IS_ERR(pwm))  in cros_ec_pwm_xlate()
186 		return pwm;  in cros_ec_pwm_xlate()
189 	pwm->args.period = EC_PWM_MAX_DUTY;  in cros_ec_pwm_xlate()
191 	return pwm;  in cros_ec_pwm_xlate()
203  * Determine the number of supported PWMs. The EC does not return the number
204  * of PWMs it supports directly, so we have to read the pwm duty cycle for
217 		 * The EC error codes map to -EOPNOTSUPP and -EINVAL,  in cros_ec_num_pwms()
221 		case -EOPNOTSUPP:	/* invalid command */  in cros_ec_num_pwms()
222 			return -ENODEV;  in cros_ec_num_pwms()
223 		case -EINVAL:		/* invalid parameter */  in cros_ec_num_pwms()
237 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);  in cros_ec_pwm_probe()
238 	struct device *dev = &pdev->dev;  in cros_ec_pwm_probe()
245 		return -EINVAL;  in cros_ec_pwm_probe()
250 		return -ENOMEM;  in cros_ec_pwm_probe()
251 	chip = &ec_pwm->chip;  in cros_ec_pwm_probe()
252 	ec_pwm->ec = ec;  in cros_ec_pwm_probe()
254 	/* PWM chip */  in cros_ec_pwm_probe()
255 	chip->dev = dev;  in cros_ec_pwm_probe()
256 	chip->ops = &cros_ec_pwm_ops;  in cros_ec_pwm_probe()
257 	chip->of_xlate = cros_ec_pwm_xlate;  in cros_ec_pwm_probe()
258 	chip->of_pwm_n_cells = 1;  in cros_ec_pwm_probe()
264 	chip->npwm = ret;  in cros_ec_pwm_probe()
265 	dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);  in cros_ec_pwm_probe()
269 		dev_err(dev, "cannot register PWM: %d\n", ret);  in cros_ec_pwm_probe()
281 	struct pwm_chip *chip = &ec_pwm->chip;  in cros_ec_pwm_remove()
290 	{ .compatible = "google,cros-ec-pwm" },
300 		.name = "cros-ec-pwm",
306 MODULE_ALIAS("platform:cros-ec-pwm");
307 MODULE_DESCRIPTION("ChromeOS EC PWM driver");