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