2  * gpio-max3191x.c - GPIO driver for Maxim MAX3191x industrial serializer
7  * Multiple chips can be daisy-chained, the spec does not impose
10  * Either of two modes is selectable: In 8-bit mode, only the state
12  * In 16-bit mode, an additional status byte is clocked out with
16  * readout of non-faulting chips in the same daisy-chain.
20  * daisy-chain.
22  * If the chips are hardwired to 8-bit mode ("modesel" pulled high),
23  * gpio-pisosr.c can be used alternatively to this driver.
29  * https://datasheets.maximintegrated.com/en/ds/MAX31953-MAX31963.pdf
49  * struct max3191x_chip - max3191x daisy-chain
52  * @nchips: number of chips in the daisy-chain
53  * @mode: current mode, 0 for 16-bit, 1 for 8-bit;
54  *	for simplicity, all chips in the daisy-chain are assumed
71  *	for simplicity, all chips in the daisy-chain are assumed
111 	return -EINVAL;  in max3191x_direction_output()
123 	return max3191x->mode == STATUS_BYTE_ENABLED ? 2 : 1;  in max3191x_wordlen()
128 	struct device *dev = max3191x->gpio.parent;  in max3191x_readout_locked()
132 	val = spi_sync(spi, &max3191x->mesg);  in max3191x_readout_locked()
138 	for (i = 0; i < max3191x->nchips; i++) {  in max3191x_readout_locked()
139 		if (max3191x->mode == STATUS_BYTE_ENABLED) {  in max3191x_readout_locked()
140 			u8 in	  = ((u8 *)max3191x->xfer.rx_buf)[i * 2];  in max3191x_readout_locked()
141 			u8 status = ((u8 *)max3191x->xfer.rx_buf)[i * 2 + 1];  in max3191x_readout_locked()
144 			__assign_bit(i, max3191x->crc_error, val);  in max3191x_readout_locked()
150 			__assign_bit(i, max3191x->overtemp, ot);  in max3191x_readout_locked()
155 			if (!max3191x->ignore_uv) {  in max3191x_readout_locked()
157 				__assign_bit(i, max3191x->undervolt1, uv1);  in max3191x_readout_locked()
163 				__assign_bit(i, max3191x->undervolt2, val);  in max3191x_readout_locked()
170 		if (max3191x->fault_pins && !max3191x->ignore_uv) {  in max3191x_readout_locked()
173 				(max3191x->fault_pins->ndescs == 1)  in max3191x_readout_locked()
174 					? max3191x->fault_pins->desc[0]  in max3191x_readout_locked()
175 					: max3191x->fault_pins->desc[i];  in max3191x_readout_locked()
183 			__assign_bit(i, max3191x->fault, val);  in max3191x_readout_locked()
197 	if (!max3191x->ignore_uv && test_bit(chipnum, max3191x->fault))  in max3191x_chip_is_faulting()
200 	if (max3191x->mode == STATUS_BYTE_DISABLED)  in max3191x_chip_is_faulting()
203 	return test_bit(chipnum, max3191x->crc_error) ||  in max3191x_chip_is_faulting()
204 	       test_bit(chipnum, max3191x->overtemp)  ||  in max3191x_chip_is_faulting()
205 	       (!max3191x->ignore_uv &&  in max3191x_chip_is_faulting()
206 		test_bit(chipnum, max3191x->undervolt1));  in max3191x_chip_is_faulting()
215 	mutex_lock(&max3191x->lock);  in max3191x_get()
222 		ret = -EIO;  in max3191x_get()
226 	in = ((u8 *)max3191x->xfer.rx_buf)[chipnum * wordlen];  in max3191x_get()
230 	mutex_unlock(&max3191x->lock);  in max3191x_get()
240 	mutex_lock(&max3191x->lock);  in max3191x_get_multiple()
245 	while ((bit = find_next_bit(mask, gpio->ngpio, bit)) != gpio->ngpio) {  in max3191x_get_multiple()
250 			ret = -EIO;  in max3191x_get_multiple()
254 		in = ((u8 *)max3191x->xfer.rx_buf)[chipnum * wordlen];  in max3191x_get_multiple()
264 	mutex_unlock(&max3191x->lock);  in max3191x_get_multiple()
275 		return -ENOTSUPP;  in max3191x_set_config()
277 	if (!max3191x->db0_pins || !max3191x->db1_pins)  in max3191x_set_config()
278 		return -EINVAL;  in max3191x_set_config()
299 		return -EINVAL;  in max3191x_set_config()
302 	if (max3191x->db0_pins->ndescs == 1)  in max3191x_set_config()
307 	mutex_lock(&max3191x->lock);  in max3191x_set_config()
308 	gpiod_set_value_cansleep(max3191x->db0_pins->desc[chipnum], db0_val);  in max3191x_set_config()
309 	gpiod_set_value_cansleep(max3191x->db1_pins->desc[chipnum], db1_val);  in max3191x_set_config()
310 	mutex_unlock(&max3191x->lock);  in max3191x_set_config()
338 	if (found == -ENOENT)  in devm_gpiod_get_array_optional_count()
342 		dev_err(dev, "ignoring %s-gpios: found %d, expected %u or 1\n",  in devm_gpiod_get_array_optional_count()
350 		dev_err(dev, "failed to get %s-gpios: %ld\n",  in devm_gpiod_get_array_optional_count()
360 	struct device *dev = &spi->dev;  in max3191x_probe()
366 		return -ENOMEM;  in max3191x_probe()
369 	max3191x->nchips = 1;  in max3191x_probe()
370 	device_property_read_u32(dev, "#daisy-chained-devices",  in max3191x_probe()
371 				 &max3191x->nchips);  in max3191x_probe()
373 	n = BITS_TO_LONGS(max3191x->nchips);  in max3191x_probe()
374 	max3191x->crc_error   = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);  in max3191x_probe()
375 	max3191x->undervolt1  = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);  in max3191x_probe()
376 	max3191x->undervolt2  = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);  in max3191x_probe()
377 	max3191x->overtemp    = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);  in max3191x_probe()
378 	max3191x->fault       = devm_kcalloc(dev, n, sizeof(long), GFP_KERNEL);  in max3191x_probe()
379 	max3191x->xfer.rx_buf = devm_kcalloc(dev, max3191x->nchips,  in max3191x_probe()
381 	if (!max3191x->crc_error || !max3191x->undervolt1 ||  in max3191x_probe()
382 	    !max3191x->overtemp  || !max3191x->undervolt2 ||  in max3191x_probe()
383 	    !max3191x->fault     || !max3191x->xfer.rx_buf)  in max3191x_probe()
384 		return -ENOMEM;  in max3191x_probe()
386 	max3191x->modesel_pins = devm_gpiod_get_array_optional_count(dev,  in max3191x_probe()
387 				 "maxim,modesel", GPIOD_ASIS, max3191x->nchips);  in max3191x_probe()
388 	max3191x->fault_pins   = devm_gpiod_get_array_optional_count(dev,  in max3191x_probe()
389 				 "maxim,fault", GPIOD_IN, max3191x->nchips);  in max3191x_probe()
390 	max3191x->db0_pins     = devm_gpiod_get_array_optional_count(dev,  in max3191x_probe()
391 				 "maxim,db0", GPIOD_OUT_LOW, max3191x->nchips);  in max3191x_probe()
392 	max3191x->db1_pins     = devm_gpiod_get_array_optional_count(dev,  in max3191x_probe()
393 				 "maxim,db1", GPIOD_OUT_LOW, max3191x->nchips);  in max3191x_probe()
395 	max3191x->mode = device_property_read_bool(dev, "maxim,modesel-8bit")  in max3191x_probe()
397 	if (max3191x->modesel_pins)  in max3191x_probe()
399 				 max3191x->modesel_pins->ndescs,  in max3191x_probe()
400 				 max3191x->modesel_pins->desc, max3191x->mode);  in max3191x_probe()
402 	max3191x->ignore_uv = device_property_read_bool(dev,  in max3191x_probe()
403 						  "maxim,ignore-undervoltage");  in max3191x_probe()
405 	if (max3191x->db0_pins && max3191x->db1_pins &&  in max3191x_probe()
406 	    max3191x->db0_pins->ndescs != max3191x->db1_pins->ndescs) {  in max3191x_probe()
407 		dev_err(dev, "ignoring maxim,db*-gpios: array len mismatch\n");  in max3191x_probe()
408 		devm_gpiod_put_array(dev, max3191x->db0_pins);  in max3191x_probe()
409 		devm_gpiod_put_array(dev, max3191x->db1_pins);  in max3191x_probe()
410 		max3191x->db0_pins = NULL;  in max3191x_probe()
411 		max3191x->db1_pins = NULL;  in max3191x_probe()
414 	max3191x->xfer.len = max3191x->nchips * max3191x_wordlen(max3191x);  in max3191x_probe()
415 	spi_message_init_with_transfers(&max3191x->mesg, &max3191x->xfer, 1);  in max3191x_probe()
417 	max3191x->gpio.label = spi->modalias;  in max3191x_probe()
418 	max3191x->gpio.owner = THIS_MODULE;  in max3191x_probe()
419 	max3191x->gpio.parent = dev;  in max3191x_probe()
420 	max3191x->gpio.base = -1;  in max3191x_probe()
421 	max3191x->gpio.ngpio = max3191x->nchips * MAX3191X_NGPIO;  in max3191x_probe()
422 	max3191x->gpio.can_sleep = true;  in max3191x_probe()
424 	max3191x->gpio.get_direction = max3191x_get_direction;  in max3191x_probe()
425 	max3191x->gpio.direction_input = max3191x_direction_input;  in max3191x_probe()
426 	max3191x->gpio.direction_output = max3191x_direction_output;  in max3191x_probe()
427 	max3191x->gpio.set = max3191x_set;  in max3191x_probe()
428 	max3191x->gpio.set_multiple = max3191x_set_multiple;  in max3191x_probe()
429 	max3191x->gpio.get = max3191x_get;  in max3191x_probe()
430 	max3191x->gpio.get_multiple = max3191x_get_multiple;  in max3191x_probe()
431 	max3191x->gpio.set_config = max3191x_set_config;  in max3191x_probe()
433 	mutex_init(&max3191x->lock);  in max3191x_probe()
435 	ret = gpiochip_add_data(&max3191x->gpio, max3191x);  in max3191x_probe()
437 		mutex_destroy(&max3191x->lock);  in max3191x_probe()
448 	gpiochip_remove(&max3191x->gpio);  in max3191x_remove()
449 	mutex_destroy(&max3191x->lock);  in max3191x_remove()
495 MODULE_AUTHOR("Lukas Wunner <lukas@wunner.de>");
496 MODULE_DESCRIPTION("GPIO driver for Maxim MAX3191x industrial serializer");