1 // SPDX-License-Identifier: GPL-2.0
3 // System Control and Management Interface (SCMI) based regulator driver
5 // Copyright (C) 2020-2021 ARM Ltd.
7 // Implements a regulator driver on top of the SCMI Voltage Protocol.
12 // capabilities and configurability of this regulator device are much more
13 // limited than the ones usually available on a standard physical regulator.
15 // The supported SCMI regulator ops are restricted to the bare minimum:
17 //  - 'status_ops': enable/disable/is_enabled
18 //  - 'voltage_ops': get_voltage_sel/set_voltage_sel
21 // Each SCMI regulator instance is associated, through the means of a proper DT
22 // entry description, to a specific SCMI Voltage Domain.
29 #include <linux/regulator/driver.h>
30 #include <linux/regulator/machine.h>
31 #include <linux/regulator/of_regulator.h>
57 	return voltage_ops->config_set(sreg->ph, sreg->id,  in scmi_reg_enable()
65 	return voltage_ops->config_set(sreg->ph, sreg->id,  in scmi_reg_disable()
75 	ret = voltage_ops->config_get(sreg->ph, sreg->id, &config);  in scmi_reg_is_enabled()
77 		dev_err(&sreg->sdev->dev,  in scmi_reg_is_enabled()
78 			"Error %d reading regulator %s status.\n",  in scmi_reg_is_enabled()
79 			ret, sreg->desc.name);  in scmi_reg_is_enabled()
92 	ret = voltage_ops->level_get(sreg->ph, sreg->id, &volt_uV);  in scmi_reg_get_voltage_sel()
96 	return sreg->desc.ops->map_voltage(rdev, volt_uV, volt_uV);  in scmi_reg_get_voltage_sel()
105 	volt_uV = sreg->desc.ops->list_voltage(rdev, selector);  in scmi_reg_set_voltage_sel()
107 		return -EINVAL;  in scmi_reg_set_voltage_sel()
109 	return voltage_ops->level_set(sreg->ph, sreg->id, 0x0, volt_uV);  in scmi_reg_set_voltage_sel()
147 	 * triplet by the SCMI Voltage Domain protocol support itself.  in scmi_config_linear_regulator_mappings()
150 	delta_uV = (vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_HIGH] -  in scmi_config_linear_regulator_mappings()
151 			vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_LOW]);  in scmi_config_linear_regulator_mappings()
153 	/* Rule out buggy negative-intervals answers from fw */  in scmi_config_linear_regulator_mappings()
155 		dev_err(&sreg->sdev->dev,  in scmi_config_linear_regulator_mappings()
156 			"Invalid volt-range %d-%duV for domain %d\n",  in scmi_config_linear_regulator_mappings()
157 			vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_LOW],  in scmi_config_linear_regulator_mappings()
158 			vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_HIGH],  in scmi_config_linear_regulator_mappings()
159 			sreg->id);  in scmi_config_linear_regulator_mappings()
160 		return -EINVAL;  in scmi_config_linear_regulator_mappings()
164 		/* Just one fixed voltage exposed by SCMI */  in scmi_config_linear_regulator_mappings()
165 		sreg->desc.fixed_uV =  in scmi_config_linear_regulator_mappings()
166 			vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_LOW];  in scmi_config_linear_regulator_mappings()
167 		sreg->desc.n_voltages = 1;  in scmi_config_linear_regulator_mappings()
168 		sreg->desc.ops = &scmi_reg_fixed_ops;  in scmi_config_linear_regulator_mappings()
171 		sreg->desc.min_uV =  in scmi_config_linear_regulator_mappings()
172 			vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_LOW];  in scmi_config_linear_regulator_mappings()
173 		sreg->desc.uV_step =  in scmi_config_linear_regulator_mappings()
174 			vinfo->levels_uv[SCMI_VOLTAGE_SEGMENT_STEP];  in scmi_config_linear_regulator_mappings()
175 		sreg->desc.linear_min_sel = 0;  in scmi_config_linear_regulator_mappings()
176 		sreg->desc.n_voltages = (delta_uV / sreg->desc.uV_step) + 1;  in scmi_config_linear_regulator_mappings()
177 		sreg->desc.ops = &scmi_reg_linear_ops;  in scmi_config_linear_regulator_mappings()
188 	sreg->desc.n_voltages = vinfo->num_levels;  in scmi_config_discrete_regulator_mappings()
190 	if (sreg->desc.n_voltages > 1) {  in scmi_config_discrete_regulator_mappings()
191 		sreg->desc.volt_table = (const unsigned int *)vinfo->levels_uv;  in scmi_config_discrete_regulator_mappings()
192 		sreg->desc.ops = &scmi_reg_discrete_ops;  in scmi_config_discrete_regulator_mappings()
194 		sreg->desc.fixed_uV = vinfo->levels_uv[0];  in scmi_config_discrete_regulator_mappings()
195 		sreg->desc.ops = &scmi_reg_fixed_ops;  in scmi_config_discrete_regulator_mappings()
204 	struct device *dev = &sreg->sdev->dev;  in scmi_regulator_common_init()
207 	vinfo = voltage_ops->info_get(sreg->ph, sreg->id);  in scmi_regulator_common_init()
209 		dev_warn(dev, "Failure to get voltage domain %d\n",  in scmi_regulator_common_init()
210 			 sreg->id);  in scmi_regulator_common_init()
211 		return -ENODEV;  in scmi_regulator_common_init()
215 	 * Regulator framework does not fully support negative voltages  in scmi_regulator_common_init()
216 	 * so we discard any voltage domain reported as supporting negative  in scmi_regulator_common_init()
218 	 * be non-negative from here on.  in scmi_regulator_common_init()
220 	if (vinfo->negative_volts_allowed) {  in scmi_regulator_common_init()
222 			 sreg->of_node->full_name);  in scmi_regulator_common_init()
223 		return -EOPNOTSUPP;  in scmi_regulator_common_init()
226 	sreg->desc.name = devm_kasprintf(dev, GFP_KERNEL, "%s", vinfo->name);  in scmi_regulator_common_init()
227 	if (!sreg->desc.name)  in scmi_regulator_common_init()
228 		return -ENOMEM;  in scmi_regulator_common_init()
230 	sreg->desc.id = sreg->id;  in scmi_regulator_common_init()
231 	sreg->desc.type = REGULATOR_VOLTAGE;  in scmi_regulator_common_init()
232 	sreg->desc.owner = THIS_MODULE;  in scmi_regulator_common_init()
233 	sreg->desc.of_match_full_name = true;  in scmi_regulator_common_init()
234 	sreg->desc.of_match = sreg->of_node->full_name;  in scmi_regulator_common_init()
235 	sreg->desc.regulators_node = "regulators";  in scmi_regulator_common_init()
236 	if (vinfo->segmented)  in scmi_regulator_common_init()
247 	sreg->conf.dev = dev;  in scmi_regulator_common_init()
250 	sreg->conf.driver_data = sreg;  in scmi_regulator_common_init()
266 	if (dom >= rinfo->num_doms)  in process_scmi_regulator_of_node()
267 		return -ENODEV;  in process_scmi_regulator_of_node()
269 	if (rinfo->sregv[dom]) {  in process_scmi_regulator_of_node()
270 		dev_err(&sdev->dev,  in process_scmi_regulator_of_node()
271 			"SCMI Voltage Domain %d already in use. Skipping: %s\n",  in process_scmi_regulator_of_node()
272 			dom, np->full_name);  in process_scmi_regulator_of_node()
273 		return -EINVAL;  in process_scmi_regulator_of_node()
276 	rinfo->sregv[dom] = devm_kzalloc(&sdev->dev,  in process_scmi_regulator_of_node()
279 	if (!rinfo->sregv[dom])  in process_scmi_regulator_of_node()
280 		return -ENOMEM;  in process_scmi_regulator_of_node()
282 	rinfo->sregv[dom]->id = dom;  in process_scmi_regulator_of_node()
283 	rinfo->sregv[dom]->sdev = sdev;  in process_scmi_regulator_of_node()
284 	rinfo->sregv[dom]->ph = ph;  in process_scmi_regulator_of_node()
288 	rinfo->sregv[dom]->of_node = np;  in process_scmi_regulator_of_node()
290 	dev_dbg(&sdev->dev,  in process_scmi_regulator_of_node()
291 		"Found SCMI Regulator entry -- OF node [%d] -> %s\n",  in process_scmi_regulator_of_node()
292 		dom, np->full_name);  in process_scmi_regulator_of_node()
301 	const struct scmi_handle *handle = sdev->handle;  in scmi_regulator_probe()
306 		return -ENODEV;  in scmi_regulator_probe()
308 	voltage_ops = handle->devm_protocol_get(sdev,  in scmi_regulator_probe()
313 	num_doms = voltage_ops->num_domains_get(ph);  in scmi_regulator_probe()
318 		dev_err(&sdev->dev, "failed to get voltage domains - err:%d\n",  in scmi_regulator_probe()
324 	rinfo = devm_kzalloc(&sdev->dev, sizeof(*rinfo), GFP_KERNEL);  in scmi_regulator_probe()
326 		return -ENOMEM;  in scmi_regulator_probe()
329 	rinfo->sregv = devm_kcalloc(&sdev->dev, num_doms,  in scmi_regulator_probe()
331 	if (!rinfo->sregv)  in scmi_regulator_probe()
332 		return -ENOMEM;  in scmi_regulator_probe()
334 	rinfo->num_doms = num_doms;  in scmi_regulator_probe()
337 	 * Start collecting into rinfo->sregv possibly good SCMI Regulators as  in scmi_regulator_probe()
338 	 * described by a well-formed DT entry and associated with an existing  in scmi_regulator_probe()
339 	 * plausible SCMI Voltage Domain number, all belonging to this SCMI  in scmi_regulator_probe()
340 	 * platform instance node (handle->dev->of_node).  in scmi_regulator_probe()
342 	of_node_get(handle->dev->of_node);  in scmi_regulator_probe()
343 	np = of_find_node_by_name(handle->dev->of_node, "regulators");  in scmi_regulator_probe()
347 		if (ret == -ENOMEM)  in scmi_regulator_probe()
352 	 * Register a regulator for each valid regulator-DT-entry that we  in scmi_regulator_probe()
354 	 * domain.  in scmi_regulator_probe()
357 		struct scmi_regulator *sreg = rinfo->sregv[d];  in scmi_regulator_probe()
368 		sreg->rdev = devm_regulator_register(&sdev->dev, &sreg->desc,  in scmi_regulator_probe()
369 						     &sreg->conf);  in scmi_regulator_probe()
370 		if (IS_ERR(sreg->rdev)) {  in scmi_regulator_probe()
371 			sreg->rdev = NULL;  in scmi_regulator_probe()
375 		dev_info(&sdev->dev,  in scmi_regulator_probe()
376 			 "Regulator %s registered for domain [%d]\n",  in scmi_regulator_probe()
377 			 sreg->desc.name, sreg->id);  in scmi_regulator_probe()
380 	dev_set_drvdata(&sdev->dev, rinfo);  in scmi_regulator_probe()
390 	rinfo = dev_get_drvdata(&sdev->dev);  in scmi_regulator_remove()
394 	for (d = 0; d < rinfo->num_doms; d++) {  in scmi_regulator_remove()
395 		if (!rinfo->sregv[d])  in scmi_regulator_remove()
397 		of_node_put(rinfo->sregv[d]->of_node);  in scmi_regulator_remove()
402 	{ SCMI_PROTOCOL_VOLTAGE,  "regulator" },
408 	.name		= "scmi-regulator",
417 MODULE_DESCRIPTION("ARM SCMI regulator driver");