4 * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
5 * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
7 * This module supports the PCA954x series of I2C multiplexer/switch chips
8 * made by Philips Semiconductors.
10 * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
13 * These chips are all controlled via the I2C bus itself, and all have a
14 * single 8-bit register. The upstream "parent" bus fans out to two,
15 * four, or eight downstream busses or channels; which of these
16 * are selected is determined by the chip type and register contents. A
17 * mux can select only one sub-bus at a time; a switch can select any
18 * combination simultaneously.
21 * pca954x.c from Kumar Gala <galak@kernel.crashing.org>
25 * pca954x.c from Ken Harrenstien
26 * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
29 * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
31 * pca9540.c from Jean Delvare <jdelvare@suse.de>.
33 * This file is licensed under the terms of the GNU General Public
34 * License version 2. This program is licensed "as is" without any
35 * warranty of any kind, whether express or implied.
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/i2c/pca954x.h>
43 #include <linux/interrupt.h>
44 #include <linux/irq.h>
45 #include <linux/module.h>
47 #include <linux/of_device.h>
48 #include <linux/of_irq.h>
50 #include <linux/slab.h>
51 #include <linux/spinlock.h>
53 #define PCA954X_MAX_NCHANS 8
55 #define PCA954X_IRQ_OFFSET 4
70 u8 enable; /* used for muxes only */
79 const struct chip_desc *chip;
81 u8 last_chan; /* last register value */
83 struct i2c_client *client;
85 struct irq_domain *irq;
86 unsigned int irq_mask;
90 /* Provide specs for the PCA954x types we know about */
91 static const struct chip_desc chips[] = {
95 .muxtype = pca954x_ismux,
101 .muxtype = pca954x_ismux,
106 .muxtype = pca954x_isswi,
112 .muxtype = pca954x_ismux,
117 .muxtype = pca954x_isswi,
121 .muxtype = pca954x_isswi,
126 .muxtype = pca954x_ismux,
130 .muxtype = pca954x_isswi,
134 static 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 },
145 MODULE_DEVICE_TABLE(i2c, pca954x_id);
148 static 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] },
159 MODULE_DEVICE_TABLE(of, pca954x_of_match);
162 /* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
163 for this as they will try to lock adapter a second time */
164 static int pca954x_reg_write(struct i2c_adapter *adap,
165 struct i2c_client *client, u8 val)
169 if (adap->algo->master_xfer) {
173 msg.addr = client->addr;
178 ret = __i2c_transfer(adap, &msg, 1);
180 if (ret >= 0 && ret != 1)
183 union i2c_smbus_data data;
184 ret = adap->algo->smbus_xfer(adap, client->addr,
187 val, I2C_SMBUS_BYTE, &data);
193 static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
195 struct pca954x *data = i2c_mux_priv(muxc);
196 struct i2c_client *client = data->client;
197 const struct chip_desc *chip = data->chip;
201 /* we make switches look like muxes, not sure how to be smarter */
202 if (chip->muxtype == pca954x_ismux)
203 regval = chan | chip->enable;
207 /* Only select the channel if its different from the last channel */
208 if (data->last_chan != regval) {
209 ret = pca954x_reg_write(muxc->parent, client, regval);
210 data->last_chan = ret < 0 ? 0 : regval;
216 static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
218 struct pca954x *data = i2c_mux_priv(muxc);
219 struct i2c_client *client = data->client;
221 if (!(data->deselect & (1 << chan)))
224 /* Deselect active channel */
226 return pca954x_reg_write(muxc->parent, client, data->last_chan);
229 static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
231 struct pca954x *data = dev_id;
232 unsigned int child_irq;
233 int ret, i, handled = 0;
235 ret = i2c_smbus_read_byte(data->client);
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);
246 return handled ? IRQ_HANDLED : IRQ_NONE;
249 static void pca954x_irq_mask(struct irq_data *idata)
251 struct pca954x *data = irq_data_get_irq_chip_data(idata);
252 unsigned int pos = idata->hwirq;
255 raw_spin_lock_irqsave(&data->lock, flags);
257 data->irq_mask &= ~BIT(pos);
259 disable_irq(data->client->irq);
261 raw_spin_unlock_irqrestore(&data->lock, flags);
264 static void pca954x_irq_unmask(struct irq_data *idata)
266 struct pca954x *data = irq_data_get_irq_chip_data(idata);
267 unsigned int pos = idata->hwirq;
270 raw_spin_lock_irqsave(&data->lock, flags);
273 enable_irq(data->client->irq);
274 data->irq_mask |= BIT(pos);
276 raw_spin_unlock_irqrestore(&data->lock, flags);
279 static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
281 if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
286 static struct irq_chip pca954x_irq_chip = {
287 .name = "i2c-mux-pca954x",
288 .irq_mask = pca954x_irq_mask,
289 .irq_unmask = pca954x_irq_unmask,
290 .irq_set_type = pca954x_irq_set_type,
293 static int pca954x_irq_setup(struct i2c_mux_core *muxc)
295 struct pca954x *data = i2c_mux_priv(muxc);
296 struct i2c_client *client = data->client;
299 if (!data->chip->has_irq || client->irq <= 0)
302 raw_spin_lock_init(&data->lock);
304 data->irq = irq_domain_add_linear(client->dev.of_node,
306 &irq_domain_simple_ops, data);
310 for (c = 0; c < data->chip->nchans; c++) {
311 irq = irq_create_mapping(data->irq, c);
312 irq_set_chip_data(irq, data);
313 irq_set_chip_and_handler(irq, &pca954x_irq_chip,
317 err = devm_request_threaded_irq(&client->dev, data->client->irq, NULL,
319 IRQF_ONESHOT | IRQF_SHARED,
324 disable_irq(data->client->irq);
328 for (c = 0; c < data->chip->nchans; c++) {
329 irq = irq_find_mapping(data->irq, c);
330 irq_dispose_mapping(irq);
332 irq_domain_remove(data->irq);
338 * I2C init/probing/exit functions
340 static int pca954x_probe(struct i2c_client *client,
341 const struct i2c_device_id *id)
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;
354 if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
357 muxc = i2c_mux_alloc(adap, &client->dev,
358 PCA954X_MAX_NCHANS, sizeof(*data), 0,
359 pca954x_select_chan, pca954x_deselect_mux);
362 data = i2c_mux_priv(muxc);
364 i2c_set_clientdata(client, muxc);
365 data->client = client;
367 /* Get the mux out of reset if a reset GPIO is specified. */
368 gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
370 return PTR_ERR(gpio);
372 /* Write the mux register at addr to verify
373 * that the mux is in fact present. This also
374 * initializes the mux to disconnected state.
376 if (i2c_smbus_write_byte(client, 0) < 0) {
377 dev_warn(&client->dev, "probe failed\n");
381 match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
383 data->chip = of_device_get_match_data(&client->dev);
385 data->chip = &chips[id->driver_data];
387 data->last_chan = 0; /* force the first selection */
389 idle_disconnect_dt = of_node &&
390 of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
392 ret = pca954x_irq_setup(muxc);
394 goto fail_del_adapters;
396 /* Now create an adapter for each channel */
397 for (num = 0; num < data->chip->nchans; num++) {
398 bool idle_disconnect_pd = false;
400 force = 0; /* dynamic adap number */
401 class = 0; /* no class by default */
403 if (num < pdata->num_modes) {
404 /* force static number */
405 force = pdata->modes[num].adap_id;
406 class = pdata->modes[num].class;
408 /* discard unconfigured channels */
410 idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
412 data->deselect |= (idle_disconnect_pd ||
413 idle_disconnect_dt) << num;
415 ret = i2c_mux_add_adapter(muxc, force, num, class);
417 goto fail_del_adapters;
420 dev_info(&client->dev,
421 "registered %d multiplexed busses for I2C %s %s\n",
422 num, data->chip->muxtype == pca954x_ismux
423 ? "mux" : "switch", client->name);
428 i2c_mux_del_adapters(muxc);
432 static int pca954x_remove(struct i2c_client *client)
434 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
435 struct pca954x *data = i2c_mux_priv(muxc);
439 for (c = 0; c < data->chip->nchans; c++) {
440 irq = irq_find_mapping(data->irq, c);
441 irq_dispose_mapping(irq);
443 irq_domain_remove(data->irq);
446 i2c_mux_del_adapters(muxc);
450 #ifdef CONFIG_PM_SLEEP
451 static int pca954x_resume(struct device *dev)
453 struct i2c_client *client = to_i2c_client(dev);
454 struct i2c_mux_core *muxc = i2c_get_clientdata(client);
455 struct pca954x *data = i2c_mux_priv(muxc);
458 return i2c_smbus_write_byte(client, 0);
462 static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
464 static struct i2c_driver pca954x_driver = {
468 .of_match_table = of_match_ptr(pca954x_of_match),
470 .probe = pca954x_probe,
471 .remove = pca954x_remove,
472 .id_table = pca954x_id,
475 module_i2c_driver(pca954x_driver);
477 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
478 MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
479 MODULE_LICENSE("GPL v2");