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38#include <linux/device.h>
39#include <linux/gpio/consumer.h>
40#include <linux/i2c.h>
41#include <linux/i2c-mux.h>
42#include <linux/interrupt.h>
43#include <linux/irq.h>
44#include <linux/module.h>
45#include <linux/of.h>
46#include <linux/of_device.h>
47#include <linux/of_irq.h>
48#include <linux/platform_data/pca954x.h>
49#include <linux/pm.h>
50#include <linux/slab.h>
51#include <linux/spinlock.h>
52
53#define PCA954X_MAX_NCHANS 8
54
55#define PCA954X_IRQ_OFFSET 4
56
57enum pca_type {
58 pca_9540,
59 pca_9542,
60 pca_9543,
61 pca_9544,
62 pca_9545,
63 pca_9546,
64 pca_9547,
65 pca_9548,
66 pca_9846,
67 pca_9847,
68 pca_9848,
69 pca_9849,
70};
71
72struct chip_desc {
73 u8 nchans;
74 u8 enable;
75 u8 has_irq;
76 enum muxtype {
77 pca954x_ismux = 0,
78 pca954x_isswi
79 } muxtype;
80};
81
82struct pca954x {
83 const struct chip_desc *chip;
84
85 u8 last_chan;
86 u8 deselect;
87 struct i2c_client *client;
88
89 struct irq_domain *irq;
90 unsigned int irq_mask;
91 raw_spinlock_t lock;
92};
93
94
95static const struct chip_desc chips[] = {
96 [pca_9540] = {
97 .nchans = 2,
98 .enable = 0x4,
99 .muxtype = pca954x_ismux,
100 },
101 [pca_9542] = {
102 .nchans = 2,
103 .enable = 0x4,
104 .has_irq = 1,
105 .muxtype = pca954x_ismux,
106 },
107 [pca_9543] = {
108 .nchans = 2,
109 .has_irq = 1,
110 .muxtype = pca954x_isswi,
111 },
112 [pca_9544] = {
113 .nchans = 4,
114 .enable = 0x4,
115 .has_irq = 1,
116 .muxtype = pca954x_ismux,
117 },
118 [pca_9545] = {
119 .nchans = 4,
120 .has_irq = 1,
121 .muxtype = pca954x_isswi,
122 },
123 [pca_9546] = {
124 .nchans = 4,
125 .muxtype = pca954x_isswi,
126 },
127 [pca_9547] = {
128 .nchans = 8,
129 .enable = 0x8,
130 .muxtype = pca954x_ismux,
131 },
132 [pca_9548] = {
133 .nchans = 8,
134 .muxtype = pca954x_isswi,
135 },
136 [pca_9846] = {
137 .nchans = 4,
138 .muxtype = pca954x_isswi,
139 },
140 [pca_9847] = {
141 .nchans = 8,
142 .enable = 0x8,
143 .muxtype = pca954x_ismux,
144 },
145 [pca_9848] = {
146 .nchans = 8,
147 .muxtype = pca954x_isswi,
148 },
149 [pca_9849] = {
150 .nchans = 4,
151 .enable = 0x4,
152 .muxtype = pca954x_ismux,
153 },
154};
155
156static const struct i2c_device_id pca954x_id[] = {
157 { "pca9540", pca_9540 },
158 { "pca9542", pca_9542 },
159 { "pca9543", pca_9543 },
160 { "pca9544", pca_9544 },
161 { "pca9545", pca_9545 },
162 { "pca9546", pca_9546 },
163 { "pca9547", pca_9547 },
164 { "pca9548", pca_9548 },
165 { "pca9846", pca_9846 },
166 { "pca9847", pca_9847 },
167 { "pca9848", pca_9848 },
168 { "pca9849", pca_9849 },
169 { }
170};
171MODULE_DEVICE_TABLE(i2c, pca954x_id);
172
173#ifdef CONFIG_OF
174static const struct of_device_id pca954x_of_match[] = {
175 { .compatible = "nxp,pca9540", .data = &chips[pca_9540] },
176 { .compatible = "nxp,pca9542", .data = &chips[pca_9542] },
177 { .compatible = "nxp,pca9543", .data = &chips[pca_9543] },
178 { .compatible = "nxp,pca9544", .data = &chips[pca_9544] },
179 { .compatible = "nxp,pca9545", .data = &chips[pca_9545] },
180 { .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
181 { .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
182 { .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
183 { .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
184 { .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
185 { .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
186 { .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
187 {}
188};
189MODULE_DEVICE_TABLE(of, pca954x_of_match);
190#endif
191
192
193
194static int pca954x_reg_write(struct i2c_adapter *adap,
195 struct i2c_client *client, u8 val)
196{
197 int ret = -ENODEV;
198
199 if (adap->algo->master_xfer) {
200 struct i2c_msg msg;
201 char buf[1];
202
203 msg.addr = client->addr;
204 msg.flags = 0;
205 msg.len = 1;
206 buf[0] = val;
207 msg.buf = buf;
208 ret = __i2c_transfer(adap, &msg, 1);
209
210 if (ret >= 0 && ret != 1)
211 ret = -EREMOTEIO;
212 } else {
213 union i2c_smbus_data data;
214 ret = adap->algo->smbus_xfer(adap, client->addr,
215 client->flags,
216 I2C_SMBUS_WRITE,
217 val, I2C_SMBUS_BYTE, &data);
218 }
219
220 return ret;
221}
222
223static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
224{
225 struct pca954x *data = i2c_mux_priv(muxc);
226 struct i2c_client *client = data->client;
227 const struct chip_desc *chip = data->chip;
228 u8 regval;
229 int ret = 0;
230
231
232 if (chip->muxtype == pca954x_ismux)
233 regval = chan | chip->enable;
234 else
235 regval = 1 << chan;
236
237
238 if (data->last_chan != regval) {
239 ret = pca954x_reg_write(muxc->parent, client, regval);
240 data->last_chan = ret < 0 ? 0 : regval;
241 }
242
243 return ret;
244}
245
246static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
247{
248 struct pca954x *data = i2c_mux_priv(muxc);
249 struct i2c_client *client = data->client;
250
251 if (!(data->deselect & (1 << chan)))
252 return 0;
253
254
255 data->last_chan = 0;
256 return pca954x_reg_write(muxc->parent, client, data->last_chan);
257}
258
259static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
260{
261 struct pca954x *data = dev_id;
262 unsigned int child_irq;
263 int ret, i, handled = 0;
264
265 ret = i2c_smbus_read_byte(data->client);
266 if (ret < 0)
267 return IRQ_NONE;
268
269 for (i = 0; i < data->chip->nchans; i++) {
270 if (ret & BIT(PCA954X_IRQ_OFFSET + i)) {
271 child_irq = irq_linear_revmap(data->irq, i);
272 handle_nested_irq(child_irq);
273 handled++;
274 }
275 }
276 return handled ? IRQ_HANDLED : IRQ_NONE;
277}
278
279static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
280{
281 if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
282 return -EINVAL;
283 return 0;
284}
285
286static struct irq_chip pca954x_irq_chip = {
287 .name = "i2c-mux-pca954x",
288 .irq_set_type = pca954x_irq_set_type,
289};
290
291static int pca954x_irq_setup(struct i2c_mux_core *muxc)
292{
293 struct pca954x *data = i2c_mux_priv(muxc);
294 struct i2c_client *client = data->client;
295 int c, irq;
296
297 if (!data->chip->has_irq || client->irq <= 0)
298 return 0;
299
300 raw_spin_lock_init(&data->lock);
301
302 data->irq = irq_domain_add_linear(client->dev.of_node,
303 data->chip->nchans,
304 &irq_domain_simple_ops, data);
305 if (!data->irq)
306 return -ENODEV;
307
308 for (c = 0; c < data->chip->nchans; c++) {
309 irq = irq_create_mapping(data->irq, c);
310 if (!irq) {
311 dev_err(&client->dev, "failed irq create map\n");
312 return -EINVAL;
313 }
314 irq_set_chip_data(irq, data);
315 irq_set_chip_and_handler(irq, &pca954x_irq_chip,
316 handle_simple_irq);
317 }
318
319 return 0;
320}
321
322static void pca954x_cleanup(struct i2c_mux_core *muxc)
323{
324 struct pca954x *data = i2c_mux_priv(muxc);
325 int c, irq;
326
327 if (data->irq) {
328 for (c = 0; c < data->chip->nchans; c++) {
329 irq = irq_find_mapping(data->irq, c);
330 irq_dispose_mapping(irq);
331 }
332 irq_domain_remove(data->irq);
333 }
334 i2c_mux_del_adapters(muxc);
335}
336
337
338
339
340static int pca954x_probe(struct i2c_client *client,
341 const struct i2c_device_id *id)
342{
343 struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
344 struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
345 struct device_node *of_node = client->dev.of_node;
346 bool idle_disconnect_dt;
347 struct gpio_desc *gpio;
348 int num, force, class;
349 struct i2c_mux_core *muxc;
350 struct pca954x *data;
351 const struct of_device_id *match;
352 int ret;
353
354 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
355 return -ENODEV;
356
357 muxc = i2c_mux_alloc(adap, &client->dev,
358 PCA954X_MAX_NCHANS, sizeof(*data), 0,
359 pca954x_select_chan, pca954x_deselect_mux);
360 if (!muxc)
361 return -ENOMEM;
362 data = i2c_mux_priv(muxc);
363
364 i2c_set_clientdata(client, muxc);
365 data->client = client;
366
367
368 gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
369 if (IS_ERR(gpio))
370 return PTR_ERR(gpio);
371
372
373
374
375
376 if (i2c_smbus_write_byte(client, 0) < 0) {
377 dev_warn(&client->dev, "probe failed\n");
378 return -ENODEV;
379 }
380
381 match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
382 if (match)
383 data->chip = of_device_get_match_data(&client->dev);
384 else
385 data->chip = &chips[id->driver_data];
386
387 data->last_chan = 0;
388
389 idle_disconnect_dt = of_node &&
390 of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
391
392 ret = pca954x_irq_setup(muxc);
393 if (ret)
394 goto fail_cleanup;
395
396
397 for (num = 0; num < data->chip->nchans; num++) {
398 bool idle_disconnect_pd = false;
399
400 force = 0;
401 class = 0;
402 if (pdata) {
403 if (num < pdata->num_modes) {
404
405 force = pdata->modes[num].adap_id;
406 class = pdata->modes[num].class;
407 } else
408
409 break;
410 idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
411 }
412 data->deselect |= (idle_disconnect_pd ||
413 idle_disconnect_dt) << num;
414
415 ret = i2c_mux_add_adapter(muxc, force, num, class);
416 if (ret)
417 goto fail_cleanup;
418 }
419
420 if (data->irq) {
421 ret = devm_request_threaded_irq(&client->dev, data->client->irq,
422 NULL, pca954x_irq_handler,
423 IRQF_ONESHOT | IRQF_SHARED,
424 "pca954x", data);
425 if (ret)
426 goto fail_cleanup;
427 }
428
429 dev_info(&client->dev,
430 "registered %d multiplexed busses for I2C %s %s\n",
431 num, data->chip->muxtype == pca954x_ismux
432 ? "mux" : "switch", client->name);
433
434 return 0;
435
436fail_cleanup:
437 pca954x_cleanup(muxc);
438 return ret;
439}
440
441static int pca954x_remove(struct i2c_client *client)
442{
443 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
444
445 pca954x_cleanup(muxc);
446 return 0;
447}
448
449#ifdef CONFIG_PM_SLEEP
450static int pca954x_resume(struct device *dev)
451{
452 struct i2c_client *client = to_i2c_client(dev);
453 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
454 struct pca954x *data = i2c_mux_priv(muxc);
455
456 data->last_chan = 0;
457 return i2c_smbus_write_byte(client, 0);
458}
459#endif
460
461static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
462
463static struct i2c_driver pca954x_driver = {
464 .driver = {
465 .name = "pca954x",
466 .pm = &pca954x_pm,
467 .of_match_table = of_match_ptr(pca954x_of_match),
468 },
469 .probe = pca954x_probe,
470 .remove = pca954x_remove,
471 .id_table = pca954x_id,
472};
473
474module_i2c_driver(pca954x_driver);
475
476MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
477MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
478MODULE_LICENSE("GPL v2");
479
