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19#include <linux/gpio.h>
20#include <linux/module.h>
21#include <linux/i2c.h>
22#include <linux/i2c-mux.h>
23#include <linux/power_supply.h>
24#include <linux/property.h>
25
26#define SBSM_MAX_BATS 4
27#define SBSM_RETRY_CNT 3
28
29
30#define SBSM_CMD_BATSYSSTATE 0x01
31#define SBSM_CMD_BATSYSSTATECONT 0x02
32#define SBSM_CMD_BATSYSINFO 0x04
33#define SBSM_CMD_LTC 0x3c
34
35#define SBSM_MASK_BAT_SUPPORTED GENMASK(3, 0)
36#define SBSM_MASK_CHARGE_BAT GENMASK(7, 4)
37#define SBSM_BIT_AC_PRESENT BIT(0)
38#define SBSM_BIT_TURBO BIT(7)
39
40#define SBSM_SMB_BAT_OFFSET 11
41struct sbsm_data {
42 struct i2c_client *client;
43 struct i2c_mux_core *muxc;
44
45 struct power_supply *psy;
46
47 u8 cur_chan;
48 struct gpio_chip chip;
49 bool is_ltc1760;
50
51 unsigned int supported_bats;
52 unsigned int last_state;
53 unsigned int last_state_cont;
54};
55
56static enum power_supply_property sbsm_props[] = {
57 POWER_SUPPLY_PROP_ONLINE,
58 POWER_SUPPLY_PROP_CHARGE_TYPE,
59};
60
61static int sbsm_read_word(struct i2c_client *client, u8 address)
62{
63 int reg, retries;
64
65 for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
66 reg = i2c_smbus_read_word_data(client, address);
67 if (reg >= 0)
68 break;
69 }
70
71 if (reg < 0) {
72 dev_err(&client->dev, "failed to read register 0x%02x\n",
73 address);
74 }
75
76 return reg;
77}
78
79static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word)
80{
81 int ret, retries;
82
83 for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
84 ret = i2c_smbus_write_word_data(client, address, word);
85 if (ret >= 0)
86 break;
87 }
88 if (ret < 0)
89 dev_err(&client->dev, "failed to write to register 0x%02x\n",
90 address);
91
92 return ret;
93}
94
95static int sbsm_get_property(struct power_supply *psy,
96 enum power_supply_property psp,
97 union power_supply_propval *val)
98{
99 struct sbsm_data *data = power_supply_get_drvdata(psy);
100 int regval = 0;
101
102 switch (psp) {
103 case POWER_SUPPLY_PROP_ONLINE:
104 regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT);
105 if (regval < 0)
106 return regval;
107 val->intval = !!(regval & SBSM_BIT_AC_PRESENT);
108 break;
109
110 case POWER_SUPPLY_PROP_CHARGE_TYPE:
111 regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
112 if (regval < 0)
113 return regval;
114
115 if ((regval & SBSM_MASK_CHARGE_BAT) == 0) {
116 val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
117 return 0;
118 }
119 val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
120
121 if (data->is_ltc1760) {
122
123 regval = sbsm_read_word(data->client, SBSM_CMD_LTC);
124 if (regval < 0)
125 return regval;
126 else if (regval & SBSM_BIT_TURBO)
127 val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
128 }
129 break;
130
131 default:
132 return -EINVAL;
133 }
134
135 return 0;
136}
137
138static int sbsm_prop_is_writeable(struct power_supply *psy,
139 enum power_supply_property psp)
140{
141 struct sbsm_data *data = power_supply_get_drvdata(psy);
142
143 return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760;
144}
145
146static int sbsm_set_property(struct power_supply *psy,
147 enum power_supply_property psp,
148 const union power_supply_propval *val)
149{
150 struct sbsm_data *data = power_supply_get_drvdata(psy);
151 int ret = -EINVAL;
152 u16 regval;
153
154 switch (psp) {
155 case POWER_SUPPLY_PROP_CHARGE_TYPE:
156
157 if (!data->is_ltc1760)
158 break;
159 regval = val->intval ==
160 POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 0;
161 ret = sbsm_write_word(data->client, SBSM_CMD_LTC, regval);
162 break;
163
164 default:
165 break;
166 }
167
168 return ret;
169}
170
171
172
173
174
175static int sbsm_select(struct i2c_mux_core *muxc, u32 chan)
176{
177 struct sbsm_data *data = i2c_mux_priv(muxc);
178 struct device *dev = &data->client->dev;
179 int ret = 0;
180 u16 reg;
181
182 if (data->cur_chan == chan)
183 return ret;
184
185
186 reg = BIT(SBSM_SMB_BAT_OFFSET + chan);
187 ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg);
188 if (ret)
189 dev_err(dev, "Failed to select channel %i\n", chan);
190 else
191 data->cur_chan = chan;
192
193 return ret;
194}
195
196static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int off)
197{
198 struct sbsm_data *data = gpiochip_get_data(gc);
199 int ret;
200
201 ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
202 if (ret < 0)
203 return ret;
204
205 return ret & BIT(off);
206}
207
208
209
210
211
212static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned int off)
213{
214 return 0;
215}
216
217static int sbsm_do_alert(struct device *dev, void *d)
218{
219 struct i2c_client *client = i2c_verify_client(dev);
220 struct i2c_driver *driver;
221
222 if (!client || client->addr != 0x0b)
223 return 0;
224
225 device_lock(dev);
226 if (client->dev.driver) {
227 driver = to_i2c_driver(client->dev.driver);
228 if (driver->alert)
229 driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0);
230 else
231 dev_warn(&client->dev, "no driver alert()!\n");
232 } else {
233 dev_dbg(&client->dev, "alert with no driver\n");
234 }
235 device_unlock(dev);
236
237 return -EBUSY;
238}
239
240static void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
241 unsigned int d)
242{
243 struct sbsm_data *sbsm = i2c_get_clientdata(client);
244
245 int ret, i, irq_bat = 0, state = 0;
246
247 ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE);
248 if (ret >= 0) {
249 irq_bat = ret ^ sbsm->last_state;
250 sbsm->last_state = ret;
251 state = ret;
252 }
253
254 ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT);
255 if ((ret >= 0) &&
256 ((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) {
257 irq_bat |= sbsm->supported_bats & state;
258 power_supply_changed(sbsm->psy);
259 }
260 sbsm->last_state_cont = ret;
261
262 for (i = 0; i < SBSM_MAX_BATS; i++) {
263 if (irq_bat & BIT(i)) {
264 device_for_each_child(&sbsm->muxc->adapter[i]->dev,
265 NULL, sbsm_do_alert);
266 }
267 }
268}
269
270static int sbsm_gpio_setup(struct sbsm_data *data)
271{
272 struct gpio_chip *gc = &data->chip;
273 struct i2c_client *client = data->client;
274 struct device *dev = &client->dev;
275 int ret;
276
277 if (!device_property_present(dev, "gpio-controller"))
278 return 0;
279
280 ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE);
281 if (ret < 0)
282 return ret;
283 data->last_state = ret;
284
285 ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT);
286 if (ret < 0)
287 return ret;
288 data->last_state_cont = ret;
289
290 gc->get = sbsm_gpio_get_value;
291 gc->direction_input = sbsm_gpio_direction_input;
292 gc->can_sleep = true;
293 gc->base = -1;
294 gc->ngpio = SBSM_MAX_BATS;
295 gc->label = client->name;
296 gc->parent = dev;
297 gc->owner = THIS_MODULE;
298
299 ret = devm_gpiochip_add_data(dev, gc, data);
300 if (ret) {
301 dev_err(dev, "devm_gpiochip_add_data failed: %d\n", ret);
302 return ret;
303 }
304
305 return ret;
306}
307
308static const struct power_supply_desc sbsm_default_psy_desc = {
309 .type = POWER_SUPPLY_TYPE_MAINS,
310 .properties = sbsm_props,
311 .num_properties = ARRAY_SIZE(sbsm_props),
312 .get_property = &sbsm_get_property,
313 .set_property = &sbsm_set_property,
314 .property_is_writeable = &sbsm_prop_is_writeable,
315};
316
317static int sbsm_probe(struct i2c_client *client,
318 const struct i2c_device_id *id)
319{
320 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
321 struct sbsm_data *data;
322 struct device *dev = &client->dev;
323 struct power_supply_desc *psy_desc;
324 struct power_supply_config psy_cfg = {};
325 int ret = 0, i;
326
327
328 if (client->addr != 0x0a)
329 return -EINVAL;
330
331 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
332 return -EPFNOSUPPORT;
333
334 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
335 if (!data)
336 return -ENOMEM;
337
338 i2c_set_clientdata(client, data);
339
340 data->client = client;
341 data->is_ltc1760 = !!strstr(id->name, "ltc1760");
342
343 ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO);
344 if (ret < 0)
345 return ret;
346 data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED;
347 data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0,
348 I2C_MUX_LOCKED, &sbsm_select, NULL);
349 if (!data->muxc) {
350 dev_err(dev, "failed to alloc i2c mux\n");
351 ret = -ENOMEM;
352 goto err_mux_alloc;
353 }
354 data->muxc->priv = data;
355
356
357 for (i = 0; i < SBSM_MAX_BATS; ++i) {
358 if (data->supported_bats & BIT(i)) {
359 ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
360 if (ret)
361 break;
362 }
363 }
364 if (ret) {
365 dev_err(dev, "failed to register i2c mux channel %d\n", i + 1);
366 goto err_mux_register;
367 }
368
369 psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc,
370 sizeof(struct power_supply_desc),
371 GFP_KERNEL);
372 if (!psy_desc) {
373 ret = -ENOMEM;
374 goto err_psy;
375 }
376
377 psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s",
378 dev_name(&client->dev));
379 if (!psy_desc->name) {
380 ret = -ENOMEM;
381 goto err_psy;
382 }
383 ret = sbsm_gpio_setup(data);
384 if (ret < 0)
385 goto err_psy;
386
387 psy_cfg.drv_data = data;
388 psy_cfg.of_node = dev->of_node;
389 data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
390 if (IS_ERR(data->psy)) {
391 ret = PTR_ERR(data->psy);
392 dev_err(dev, "failed to register power supply %s\n",
393 psy_desc->name);
394 goto err_psy;
395 }
396
397 return 0;
398
399err_psy:
400err_mux_register:
401 i2c_mux_del_adapters(data->muxc);
402
403err_mux_alloc:
404 return ret;
405}
406
407static int sbsm_remove(struct i2c_client *client)
408{
409 struct sbsm_data *data = i2c_get_clientdata(client);
410
411 i2c_mux_del_adapters(data->muxc);
412 return 0;
413}
414
415static const struct i2c_device_id sbsm_ids[] = {
416 { "sbs-manager", 0 },
417 { "ltc1760", 0 },
418 { }
419};
420MODULE_DEVICE_TABLE(i2c, sbsm_ids);
421
422#ifdef CONFIG_OF
423static const struct of_device_id sbsm_dt_ids[] = {
424 { .compatible = "sbs,sbs-manager" },
425 { .compatible = "lltc,ltc1760" },
426 { }
427};
428MODULE_DEVICE_TABLE(of, sbsm_dt_ids);
429#endif
430
431static struct i2c_driver sbsm_driver = {
432 .driver = {
433 .name = "sbsm",
434 .of_match_table = of_match_ptr(sbsm_dt_ids),
435 },
436 .probe = sbsm_probe,
437 .remove = sbsm_remove,
438 .alert = sbsm_alert,
439 .id_table = sbsm_ids
440};
441module_i2c_driver(sbsm_driver);
442
443MODULE_LICENSE("GPL");
444MODULE_AUTHOR("Karl-Heinz Schneider <karl-heinz@schneider-inet.de>");
445MODULE_DESCRIPTION("SBSM Smart Battery System Manager");
446
