1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Power supply driver for ChromeOS EC based Peripheral Device Charger.
4 *
5 * Copyright 2020 Google LLC.
6 */
7
8#include <linux/module.h>
9#include <linux/notifier.h>
10#include <linux/platform_data/cros_ec_commands.h>
11#include <linux/platform_data/cros_ec_proto.h>
12#include <linux/platform_device.h>
13#include <linux/power_supply.h>
14#include <linux/slab.h>
15#include <linux/stringify.h>
16#include <linux/types.h>
17#include <asm/unaligned.h>
18
19#define DRV_NAME "cros-ec-pchg"
20#define PCHG_DIR_PREFIX "peripheral"
21#define PCHG_DIR_NAME PCHG_DIR_PREFIX "%d"
22#define PCHG_DIR_NAME_LENGTH \
23 sizeof(PCHG_DIR_PREFIX __stringify(EC_PCHG_MAX_PORTS))
24#define PCHG_CACHE_UPDATE_DELAY msecs_to_jiffies(500)
25
26struct port_data {
27 int port_number;
28 char name[PCHG_DIR_NAME_LENGTH];
29 struct power_supply *psy;
30 struct power_supply_desc psy_desc;
31 int psy_status;
32 int battery_percentage;
33 int charge_type;
34 struct charger_data *charger;
35 unsigned long last_update;
36};
37
38struct charger_data {
39 struct device *dev;
40 struct cros_ec_dev *ec_dev;
41 struct cros_ec_device *ec_device;
42 int num_registered_psy;
43 struct port_data *ports[EC_PCHG_MAX_PORTS];
44 struct notifier_block notifier;
45};
46
47static enum power_supply_property cros_pchg_props[] = {
48 POWER_SUPPLY_PROP_STATUS,
49 POWER_SUPPLY_PROP_CHARGE_TYPE,
50 POWER_SUPPLY_PROP_CAPACITY,
51 POWER_SUPPLY_PROP_SCOPE,
52};
53
54static int cros_pchg_ec_command(const struct charger_data *charger,
55 unsigned int version,
56 unsigned int command,
57 const void *outdata,
58 unsigned int outsize,
59 void *indata,
60 unsigned int insize)
61{
62 struct cros_ec_dev *ec_dev = charger->ec_dev;
63 struct cros_ec_command *msg;
64 int ret;
65
66 msg = kzalloc(struct_size(msg, data, max(outsize, insize)), GFP_KERNEL);
67 if (!msg)
68 return -ENOMEM;
69
70 msg->version = version;
71 msg->command = ec_dev->cmd_offset + command;
72 msg->outsize = outsize;
73 msg->insize = insize;
74
75 if (outsize)
76 memcpy(msg->data, outdata, outsize);
77
78 ret = cros_ec_cmd_xfer_status(ec_dev: charger->ec_device, msg);
79 if (ret >= 0 && insize)
80 memcpy(indata, msg->data, insize);
81
82 kfree(objp: msg);
83 return ret;
84}
85
86static const unsigned int pchg_cmd_version = 1;
87
88static bool cros_pchg_cmd_ver_check(const struct charger_data *charger)
89{
90 struct ec_params_get_cmd_versions_v1 req;
91 struct ec_response_get_cmd_versions rsp;
92 int ret;
93
94 req.cmd = EC_CMD_PCHG;
95 ret = cros_pchg_ec_command(charger, version: 1, EC_CMD_GET_CMD_VERSIONS,
96 outdata: &req, outsize: sizeof(req), indata: &rsp, insize: sizeof(rsp));
97 if (ret < 0) {
98 dev_warn(charger->dev,
99 "Unable to get versions of EC_CMD_PCHG (err:%d)\n",
100 ret);
101 return false;
102 }
103
104 return !!(rsp.version_mask & BIT(pchg_cmd_version));
105}
106
107static int cros_pchg_port_count(const struct charger_data *charger)
108{
109 struct ec_response_pchg_count rsp;
110 int ret;
111
112 ret = cros_pchg_ec_command(charger, version: 0, EC_CMD_PCHG_COUNT,
113 NULL, outsize: 0, indata: &rsp, insize: sizeof(rsp));
114 if (ret < 0) {
115 dev_warn(charger->dev,
116 "Unable to get number or ports (err:%d)\n", ret);
117 return ret;
118 }
119
120 return rsp.port_count;
121}
122
123static int cros_pchg_get_status(struct port_data *port)
124{
125 struct charger_data *charger = port->charger;
126 struct ec_params_pchg req;
127 struct ec_response_pchg rsp;
128 struct device *dev = charger->dev;
129 int old_status = port->psy_status;
130 int old_percentage = port->battery_percentage;
131 int ret;
132
133 req.port = port->port_number;
134 ret = cros_pchg_ec_command(charger, version: pchg_cmd_version, EC_CMD_PCHG,
135 outdata: &req, outsize: sizeof(req), indata: &rsp, insize: sizeof(rsp));
136 if (ret < 0) {
137 dev_err(dev, "Unable to get port.%d status (err:%d)\n",
138 port->port_number, ret);
139 return ret;
140 }
141
142 switch (rsp.state) {
143 case PCHG_STATE_RESET:
144 case PCHG_STATE_INITIALIZED:
145 case PCHG_STATE_ENABLED:
146 default:
147 port->psy_status = POWER_SUPPLY_STATUS_UNKNOWN;
148 port->charge_type = POWER_SUPPLY_CHARGE_TYPE_NONE;
149 break;
150 case PCHG_STATE_DETECTED:
151 port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
152 port->charge_type = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
153 break;
154 case PCHG_STATE_CHARGING:
155 port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
156 port->charge_type = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
157 break;
158 case PCHG_STATE_FULL:
159 port->psy_status = POWER_SUPPLY_STATUS_FULL;
160 port->charge_type = POWER_SUPPLY_CHARGE_TYPE_NONE;
161 break;
162 }
163
164 port->battery_percentage = rsp.battery_percentage;
165
166 if (port->psy_status != old_status ||
167 port->battery_percentage != old_percentage)
168 power_supply_changed(psy: port->psy);
169
170 dev_dbg(dev,
171 "Port %d: state=%d battery=%d%%\n",
172 port->port_number, rsp.state, rsp.battery_percentage);
173
174 return 0;
175}
176
177static int cros_pchg_get_port_status(struct port_data *port, bool ratelimit)
178{
179 int ret;
180
181 if (ratelimit &&
182 time_is_after_jiffies(port->last_update + PCHG_CACHE_UPDATE_DELAY))
183 return 0;
184
185 ret = cros_pchg_get_status(port);
186 if (ret < 0)
187 return ret;
188
189 port->last_update = jiffies;
190
191 return ret;
192}
193
194static int cros_pchg_get_prop(struct power_supply *psy,
195 enum power_supply_property psp,
196 union power_supply_propval *val)
197{
198 struct port_data *port = power_supply_get_drvdata(psy);
199
200 switch (psp) {
201 case POWER_SUPPLY_PROP_STATUS:
202 case POWER_SUPPLY_PROP_CAPACITY:
203 case POWER_SUPPLY_PROP_CHARGE_TYPE:
204 cros_pchg_get_port_status(port, ratelimit: true);
205 break;
206 default:
207 break;
208 }
209
210 switch (psp) {
211 case POWER_SUPPLY_PROP_STATUS:
212 val->intval = port->psy_status;
213 break;
214 case POWER_SUPPLY_PROP_CAPACITY:
215 val->intval = port->battery_percentage;
216 break;
217 case POWER_SUPPLY_PROP_CHARGE_TYPE:
218 val->intval = port->charge_type;
219 break;
220 case POWER_SUPPLY_PROP_SCOPE:
221 val->intval = POWER_SUPPLY_SCOPE_DEVICE;
222 break;
223 default:
224 return -EINVAL;
225 }
226
227 return 0;
228}
229
230static int cros_pchg_event(const struct charger_data *charger)
231{
232 int i;
233
234 for (i = 0; i < charger->num_registered_psy; i++)
235 cros_pchg_get_port_status(port: charger->ports[i], ratelimit: false);
236
237 return NOTIFY_OK;
238}
239
240static int cros_ec_notify(struct notifier_block *nb,
241 unsigned long queued_during_suspend,
242 void *data)
243{
244 struct cros_ec_device *ec_dev = data;
245 struct charger_data *charger =
246 container_of(nb, struct charger_data, notifier);
247 u32 host_event;
248
249 if (ec_dev->event_data.event_type != EC_MKBP_EVENT_PCHG ||
250 ec_dev->event_size != sizeof(host_event))
251 return NOTIFY_DONE;
252
253 host_event = get_unaligned_le32(p: &ec_dev->event_data.data.host_event);
254
255 if (!(host_event & EC_MKBP_PCHG_DEVICE_EVENT))
256 return NOTIFY_DONE;
257
258 return cros_pchg_event(charger);
259}
260
261static int cros_pchg_probe(struct platform_device *pdev)
262{
263 struct device *dev = &pdev->dev;
264 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev: dev->parent);
265 struct cros_ec_device *ec_device = ec_dev->ec_dev;
266 struct power_supply_desc *psy_desc;
267 struct charger_data *charger;
268 struct power_supply *psy;
269 struct port_data *port;
270 struct notifier_block *nb;
271 int num_ports;
272 int ret;
273 int i;
274
275 charger = devm_kzalloc(dev, size: sizeof(*charger), GFP_KERNEL);
276 if (!charger)
277 return -ENOMEM;
278
279 charger->dev = dev;
280 charger->ec_dev = ec_dev;
281 charger->ec_device = ec_device;
282
283 platform_set_drvdata(pdev, data: charger);
284
285 ret = cros_pchg_port_count(charger);
286 if (ret <= 0) {
287 /*
288 * This feature is enabled by the EC and the kernel driver is
289 * included by default for CrOS devices. Don't need to be loud
290 * since this error can be normal.
291 */
292 dev_info(dev, "No peripheral charge ports (err:%d)\n", ret);
293 return -ENODEV;
294 }
295
296 if (!cros_pchg_cmd_ver_check(charger)) {
297 dev_err(dev, "EC_CMD_PCHG version %d isn't available.\n",
298 pchg_cmd_version);
299 return -EOPNOTSUPP;
300 }
301
302 num_ports = ret;
303 if (num_ports > EC_PCHG_MAX_PORTS) {
304 dev_err(dev, "Too many peripheral charge ports (%d)\n",
305 num_ports);
306 return -ENOBUFS;
307 }
308
309 dev_info(dev, "%d peripheral charge ports found\n", num_ports);
310
311 for (i = 0; i < num_ports; i++) {
312 struct power_supply_config psy_cfg = {};
313
314 port = devm_kzalloc(dev, size: sizeof(*port), GFP_KERNEL);
315 if (!port)
316 return -ENOMEM;
317
318 port->charger = charger;
319 port->port_number = i;
320 snprintf(buf: port->name, size: sizeof(port->name), PCHG_DIR_NAME, i);
321
322 psy_desc = &port->psy_desc;
323 psy_desc->name = port->name;
324 psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
325 psy_desc->get_property = cros_pchg_get_prop;
326 psy_desc->external_power_changed = NULL;
327 psy_desc->properties = cros_pchg_props;
328 psy_desc->num_properties = ARRAY_SIZE(cros_pchg_props);
329 psy_cfg.drv_data = port;
330
331 psy = devm_power_supply_register(parent: dev, desc: psy_desc, cfg: &psy_cfg);
332 if (IS_ERR(ptr: psy))
333 return dev_err_probe(dev, err: PTR_ERR(ptr: psy),
334 fmt: "Failed to register power supply\n");
335 port->psy = psy;
336
337 charger->ports[charger->num_registered_psy++] = port;
338 }
339
340 if (!charger->num_registered_psy)
341 return -ENODEV;
342
343 nb = &charger->notifier;
344 nb->notifier_call = cros_ec_notify;
345 ret = blocking_notifier_chain_register(nh: &ec_dev->ec_dev->event_notifier,
346 nb);
347 if (ret < 0)
348 dev_err(dev, "Failed to register notifier (err:%d)\n", ret);
349
350 return 0;
351}
352
353#ifdef CONFIG_PM_SLEEP
354static int __maybe_unused cros_pchg_resume(struct device *dev)
355{
356 struct charger_data *charger = dev_get_drvdata(dev);
357
358 /*
359 * Sync all ports on resume in case reports from EC are lost during
360 * the last suspend.
361 */
362 cros_pchg_event(charger);
363
364 return 0;
365}
366#endif
367
368static SIMPLE_DEV_PM_OPS(cros_pchg_pm_ops, NULL, cros_pchg_resume);
369
370static struct platform_driver cros_pchg_driver = {
371 .driver = {
372 .name = DRV_NAME,
373 .pm = &cros_pchg_pm_ops,
374 },
375 .probe = cros_pchg_probe
376};
377
378module_platform_driver(cros_pchg_driver);
379
380MODULE_LICENSE("GPL");
381MODULE_DESCRIPTION("ChromeOS EC peripheral device charger");
382MODULE_ALIAS("platform:" DRV_NAME);
383

source code of linux/drivers/power/supply/cros_peripheral_charger.c