1 // SPDX-License-Identifier: GPL-2.0
3  * Expose a PWM controlled by the ChromeOS EC to the host processor.
16 #include <dt-bindings/mfd/cros_ec.h>
19  * struct cros_ec_pwm_device - Driver data for EC PWM
21  * @ec: Pointer to EC device
25 	struct cros_ec_device *ec;  member
44 		return -EINVAL;  in cros_ec_dt_type_to_pwm_type()
51 	struct cros_ec_device *ec = ec_pwm->ec;  in cros_ec_pwm_set_duty()  local
62 	msg->version = 0;  in cros_ec_pwm_set_duty()
63 	msg->command = EC_CMD_PWM_SET_DUTY;  in cros_ec_pwm_set_duty()
64 	msg->insize = 0;  in cros_ec_pwm_set_duty()
65 	msg->outsize = sizeof(*params);  in cros_ec_pwm_set_duty()
67 	params->duty = duty;  in cros_ec_pwm_set_duty()
69 	if (ec_pwm->use_pwm_type) {  in cros_ec_pwm_set_duty()
70 		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);  in cros_ec_pwm_set_duty()
72 			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);  in cros_ec_pwm_set_duty()
75 		params->index = 0;  in cros_ec_pwm_set_duty()
77 		params->pwm_type = EC_PWM_TYPE_GENERIC;  in cros_ec_pwm_set_duty()
78 		params->index = index;  in cros_ec_pwm_set_duty()
81 	return cros_ec_cmd_xfer_status(ec, msg);  in cros_ec_pwm_set_duty()
84 static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, bool use_pwm_type, u8 index)  in cros_ec_pwm_get_duty()  argument
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()
106 		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);  in cros_ec_pwm_get_duty()
108 			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);  in cros_ec_pwm_get_duty()
111 		params->index = 0;  in cros_ec_pwm_get_duty()
113 		params->pwm_type = EC_PWM_TYPE_GENERIC;  in cros_ec_pwm_get_duty()
114 		params->index = index;  in cros_ec_pwm_get_duty()
117 	ret = cros_ec_cmd_xfer_status(ec, msg);  in cros_ec_pwm_get_duty()
121 	return resp->duty;  in cros_ec_pwm_get_duty()
131 	/* The EC won't let us change the period */  in cros_ec_pwm_apply()
132 	if (state->period != EC_PWM_MAX_DUTY)  in cros_ec_pwm_apply()
133 		return -EINVAL;  in cros_ec_pwm_apply()
135 	if (state->polarity != PWM_POLARITY_NORMAL)  in cros_ec_pwm_apply()
136 		return -EINVAL;  in cros_ec_pwm_apply()
139 	 * EC doesn't separate the concept of duty cycle and enabled, but  in cros_ec_pwm_apply()
142 	duty_cycle = state->enabled ? state->duty_cycle : 0;  in cros_ec_pwm_apply()
144 	ret = cros_ec_pwm_set_duty(ec_pwm, pwm->hwpwm, duty_cycle);  in cros_ec_pwm_apply()
157 	ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, pwm->hwpwm);  in cros_ec_pwm_get_state()
163 	state->enabled = (ret > 0);  in cros_ec_pwm_get_state()
164 	state->duty_cycle = ret;  in cros_ec_pwm_get_state()
165 	state->period = EC_PWM_MAX_DUTY;  in cros_ec_pwm_get_state()
166 	state->polarity = PWM_POLARITY_NORMAL;  in cros_ec_pwm_get_state()
177  * Determine the number of supported PWMs. The EC does not return the number
181 static int cros_ec_num_pwms(struct cros_ec_device *ec)  in cros_ec_num_pwms()  argument
191 		ret = cros_ec_pwm_get_duty(ec, false, i);  in cros_ec_num_pwms()
195 		 * The EC error codes map to -EOPNOTSUPP and -EINVAL,  in cros_ec_num_pwms()
199 		case -EOPNOTSUPP:	/* invalid command */  in cros_ec_num_pwms()
200 			return -ENODEV;  in cros_ec_num_pwms()
201 		case -EINVAL:		/* invalid parameter */  in cros_ec_num_pwms()
215 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);  in cros_ec_pwm_probe()  local
216 	struct device *dev = &pdev->dev;  in cros_ec_pwm_probe()
217 	struct device_node *np = pdev->dev.of_node;  in cros_ec_pwm_probe()
224 	if (!ec)  in cros_ec_pwm_probe()
225 		return dev_err_probe(dev, -EINVAL, "no parent EC device\n");  in cros_ec_pwm_probe()
227 	if (of_device_is_compatible(np, "google,cros-ec-pwm-type")) {  in cros_ec_pwm_probe()
231 		ret = cros_ec_num_pwms(ec);  in cros_ec_pwm_probe()
242 	ec_pwm->use_pwm_type = use_pwm_type;  in cros_ec_pwm_probe()
243 	ec_pwm->ec = ec;  in cros_ec_pwm_probe()
246 	chip->ops = &cros_ec_pwm_ops;  in cros_ec_pwm_probe()
257 		chip->pwms[i].args.period = EC_PWM_MAX_DUTY;  in cros_ec_pwm_probe()
259 	dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);  in cros_ec_pwm_probe()
270 	{ .compatible = "google,cros-ec-pwm" },
271 	{ .compatible = "google,cros-ec-pwm-type" },
280 		.name = "cros-ec-pwm",
286 MODULE_ALIAS("platform:cros-ec-pwm");
287 MODULE_DESCRIPTION("ChromeOS EC PWM driver");