gpio-ljca.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Intel La Jolla Cove Adapter USB-GPIO driver
  4 *
  5 * Copyright (c) 2023, Intel Corporation.
  6 */
  7
  8#include <linux/acpi.h>
  9#include <linux/auxiliary_bus.h>
 10#include <linux/bitfield.h>
 11#include <linux/bitops.h>
 12#include <linux/dev_printk.h>
 13#include <linux/gpio/driver.h>
 14#include <linux/irq.h>
 15#include <linux/kernel.h>
 16#include <linux/kref.h>
 17#include <linux/module.h>
 18#include <linux/slab.h>
 19#include <linux/types.h>
 20#include <linux/usb/ljca.h>
 21
 22/* GPIO commands */
 23#define LJCA_GPIO_CONFIG		1
 24#define LJCA_GPIO_READ			2
 25#define LJCA_GPIO_WRITE			3
 26#define LJCA_GPIO_INT_EVENT		4
 27#define LJCA_GPIO_INT_MASK		5
 28#define LJCA_GPIO_INT_UNMASK		6
 29
 30#define LJCA_GPIO_CONF_DISABLE		BIT(0)
 31#define LJCA_GPIO_CONF_INPUT		BIT(1)
 32#define LJCA_GPIO_CONF_OUTPUT		BIT(2)
 33#define LJCA_GPIO_CONF_PULLUP		BIT(3)
 34#define LJCA_GPIO_CONF_PULLDOWN		BIT(4)
 35#define LJCA_GPIO_CONF_DEFAULT		BIT(5)
 36#define LJCA_GPIO_CONF_INTERRUPT	BIT(6)
 37#define LJCA_GPIO_INT_TYPE		BIT(7)
 38
 39#define LJCA_GPIO_CONF_EDGE		FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
 40#define LJCA_GPIO_CONF_LEVEL		FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)
 41
 42/* Intentional overlap with PULLUP / PULLDOWN */
 43#define LJCA_GPIO_CONF_SET		BIT(3)
 44#define LJCA_GPIO_CONF_CLR		BIT(4)
 45
 46#define LJCA_GPIO_BUF_SIZE		60u
 47
 48struct ljca_gpio_op {
 49	u8 index;
 50	u8 value;
 51} __packed;
 52
 53struct ljca_gpio_packet {
 54	u8 num;
 55	struct ljca_gpio_op item[] __counted_by(num);
 56} __packed;
 57
 58struct ljca_gpio_dev {
 59	struct ljca_client *ljca;
 60	struct gpio_chip gc;
 61	struct ljca_gpio_info *gpio_info;
 62	DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
 63	DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
 64	DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
 65	DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
 66	u8 *connect_mode;
 67	/* protect irq bus */
 68	struct mutex irq_lock;
 69	struct work_struct work;
 70	/* protect package transfer to hardware */
 71	struct mutex trans_lock;
 72
 73	u8 obuf[LJCA_GPIO_BUF_SIZE];
 74	u8 ibuf[LJCA_GPIO_BUF_SIZE];
 75};
 76
 77static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
 78			    u8 config)
 79{
 80	struct ljca_gpio_packet *packet =
 81				(struct ljca_gpio_packet *)ljca_gpio->obuf;
 82	int ret;
 83
 84	mutex_lock(&ljca_gpio->trans_lock);
 85	packet->num = 1;
 86	packet->item[0].index = gpio_id;
 87	packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id];
 88
 89	ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_CONFIG, (u8 *)packet,
 90			    struct_size(packet, item, packet->num), NULL, 0);
 91	mutex_unlock(&ljca_gpio->trans_lock);
 92
 93	return ret < 0 ? ret : 0;
 94}
 95
 96static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
 97{
 98	struct ljca_gpio_packet *ack_packet =
 99				(struct ljca_gpio_packet *)ljca_gpio->ibuf;
100	struct ljca_gpio_packet *packet =
101				(struct ljca_gpio_packet *)ljca_gpio->obuf;
102	int ret;
103
104	mutex_lock(&ljca_gpio->trans_lock);
105	packet->num = 1;
106	packet->item[0].index = gpio_id;
107	ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_READ, (u8 *)packet,
108			    struct_size(packet, item, packet->num),
109			    ljca_gpio->ibuf, LJCA_GPIO_BUF_SIZE);
110
111	if (ret <= 0 || ack_packet->num != packet->num) {
112		dev_err(&ljca_gpio->ljca->auxdev.dev,
113			"read package error, gpio_id: %u num: %u ret: %d\n",
114			gpio_id, ack_packet->num, ret);
115		ret = ret < 0 ? ret : -EIO;
116	}
117	mutex_unlock(&ljca_gpio->trans_lock);
118
119	return ret < 0 ? ret : ack_packet->item[0].value > 0;
120}
121
122static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, int value)
123{
124	struct ljca_gpio_packet *packet =
125			(struct ljca_gpio_packet *)ljca_gpio->obuf;
126	int ret;
127
128	mutex_lock(&ljca_gpio->trans_lock);
129	packet->num = 1;
130	packet->item[0].index = gpio_id;
131	packet->item[0].value = value & 1;
132
133	ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_WRITE, (u8 *)packet,
134			    struct_size(packet, item, packet->num), NULL, 0);
135	mutex_unlock(&ljca_gpio->trans_lock);
136
137	return ret < 0 ? ret : 0;
138}
139
140static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
141{
142	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
143
144	return ljca_gpio_read(ljca_gpio, offset);
145}
146
147static int ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
148			       int val)
149{
150	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
151	int ret;
152
153	ret = ljca_gpio_write(ljca_gpio, offset, val);
154	if (ret)
155		dev_err(chip->parent,
156			"set value failed offset: %u val: %d ret: %d\n",
157			offset, val, ret);
158
159	return ret;
160}
161
162static int ljca_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
163{
164	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
165	u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR;
166	int ret;
167
168	ret = ljca_gpio_config(ljca_gpio, offset, config);
169	if (ret)
170		return ret;
171
172	clear_bit(offset, ljca_gpio->output_enabled);
173
174	return 0;
175}
176
177static int ljca_gpio_direction_output(struct gpio_chip *chip,
178				      unsigned int offset, int val)
179{
180	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
181	u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR;
182	int ret;
183
184	ret = ljca_gpio_config(ljca_gpio, offset, config);
185	if (ret)
186		return ret;
187
188	ret = ljca_gpio_set_value(chip, offset, val);
189	if (ret)
190		return ret;
191
192	set_bit(offset, ljca_gpio->output_enabled);
193
194	return 0;
195}
196
197static int ljca_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
198{
199	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
200
201	if (test_bit(offset, ljca_gpio->output_enabled))
202		return GPIO_LINE_DIRECTION_OUT;
203
204	return GPIO_LINE_DIRECTION_IN;
205}
206
207static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
208				unsigned long config)
209{
210	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
211
212	ljca_gpio->connect_mode[offset] = 0;
213	switch (pinconf_to_config_param(config)) {
214	case PIN_CONFIG_BIAS_PULL_UP:
215		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP;
216		break;
217	case PIN_CONFIG_BIAS_PULL_DOWN:
218		ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN;
219		break;
220	case PIN_CONFIG_DRIVE_PUSH_PULL:
221	case PIN_CONFIG_PERSIST_STATE:
222		break;
223	default:
224		return -ENOTSUPP;
225	}
226
227	return 0;
228}
229
230static int ljca_gpio_init_valid_mask(struct gpio_chip *chip,
231				     unsigned long *valid_mask,
232				     unsigned int ngpios)
233{
234	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
235
236	WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
237	bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);
238
239	return 0;
240}
241
242static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip,
243					  unsigned long *valid_mask,
244					  unsigned int ngpios)
245{
246	ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
247}
248
249static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id,
250			   bool enable)
251{
252	struct ljca_gpio_packet *packet =
253			(struct ljca_gpio_packet *)ljca_gpio->obuf;
254	int ret;
255
256	mutex_lock(&ljca_gpio->trans_lock);
257	packet->num = 1;
258	packet->item[0].index = gpio_id;
259	packet->item[0].value = 0;
260
261	ret = ljca_transfer(ljca_gpio->ljca,
262			    enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK,
263			    (u8 *)packet, struct_size(packet, item, packet->num),
264			    NULL, 0);
265	mutex_unlock(&ljca_gpio->trans_lock);
266
267	return ret < 0 ? ret : 0;
268}
269
270static void ljca_gpio_async(struct work_struct *work)
271{
272	struct ljca_gpio_dev *ljca_gpio =
273			container_of(work, struct ljca_gpio_dev, work);
274	int gpio_id, unmasked;
275
276	for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
277		clear_bit(gpio_id, ljca_gpio->reenable_irqs);
278		unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
279		if (unmasked)
280			ljca_enable_irq(ljca_gpio, gpio_id, true);
281	}
282}
283
284static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data,
285			       int len)
286{
287	const struct ljca_gpio_packet *packet = evt_data;
288	struct ljca_gpio_dev *ljca_gpio = context;
289	int i;
290
291	if (cmd != LJCA_GPIO_INT_EVENT)
292		return;
293
294	for (i = 0; i < packet->num; i++) {
295		generic_handle_domain_irq(ljca_gpio->gc.irq.domain,
296					packet->item[i].index);
297		set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
298	}
299
300	schedule_work(&ljca_gpio->work);
301}
302
303static void ljca_irq_unmask(struct irq_data *irqd)
304{
305	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
306	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
307	int gpio_id = irqd_to_hwirq(irqd);
308
309	gpiochip_enable_irq(gc, gpio_id);
310	set_bit(gpio_id, ljca_gpio->unmasked_irqs);
311}
312
313static void ljca_irq_mask(struct irq_data *irqd)
314{
315	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
316	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
317	int gpio_id = irqd_to_hwirq(irqd);
318
319	clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
320	gpiochip_disable_irq(gc, gpio_id);
321}
322
323static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
324{
325	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
326	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
327	int gpio_id = irqd_to_hwirq(irqd);
328
329	ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
330	switch (type) {
331	case IRQ_TYPE_LEVEL_HIGH:
332		ljca_gpio->connect_mode[gpio_id] |=
333			(LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP);
334		break;
335	case IRQ_TYPE_LEVEL_LOW:
336		ljca_gpio->connect_mode[gpio_id] |=
337			(LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN);
338		break;
339	case IRQ_TYPE_EDGE_BOTH:
340		break;
341	case IRQ_TYPE_EDGE_RISING:
342		ljca_gpio->connect_mode[gpio_id] |=
343			(LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP);
344		break;
345	case IRQ_TYPE_EDGE_FALLING:
346		ljca_gpio->connect_mode[gpio_id] |=
347			(LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN);
348		break;
349	default:
350		return -EINVAL;
351	}
352
353	return 0;
354}
355
356static void ljca_irq_bus_lock(struct irq_data *irqd)
357{
358	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
359	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
360
361	mutex_lock(&ljca_gpio->irq_lock);
362}
363
364static void ljca_irq_bus_unlock(struct irq_data *irqd)
365{
366	struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
367	struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
368	int gpio_id = irqd_to_hwirq(irqd);
369	int enabled, unmasked;
370
371	enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
372	unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
373
374	if (enabled != unmasked) {
375		if (unmasked) {
376			ljca_gpio_config(ljca_gpio, gpio_id, 0);
377			ljca_enable_irq(ljca_gpio, gpio_id, true);
378			set_bit(gpio_id, ljca_gpio->enabled_irqs);
379		} else {
380			ljca_enable_irq(ljca_gpio, gpio_id, false);
381			clear_bit(gpio_id, ljca_gpio->enabled_irqs);
382		}
383	}
384
385	mutex_unlock(&ljca_gpio->irq_lock);
386}
387
388static const struct irq_chip ljca_gpio_irqchip = {
389	.name = "ljca-irq",
390	.irq_mask = ljca_irq_mask,
391	.irq_unmask = ljca_irq_unmask,
392	.irq_set_type = ljca_irq_set_type,
393	.irq_bus_lock = ljca_irq_bus_lock,
394	.irq_bus_sync_unlock = ljca_irq_bus_unlock,
395	.flags = IRQCHIP_IMMUTABLE,
396	GPIOCHIP_IRQ_RESOURCE_HELPERS,
397};
398
399static int ljca_gpio_probe(struct auxiliary_device *auxdev,
400			   const struct auxiliary_device_id *aux_dev_id)
401{
402	struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
403	struct ljca_gpio_dev *ljca_gpio;
404	struct gpio_irq_chip *girq;
405	int ret;
406
407	ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
408	if (!ljca_gpio)
409		return -ENOMEM;
410
411	ljca_gpio->ljca = ljca;
412	ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
413	ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
414					       ljca_gpio->gpio_info->num,
415					       sizeof(*ljca_gpio->connect_mode),
416					       GFP_KERNEL);
417	if (!ljca_gpio->connect_mode)
418		return -ENOMEM;
419
420	ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
421	if (ret)
422		return ret;
423
424	ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->trans_lock);
425	if (ret)
426		return ret;
427
428	ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
429	ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
430	ljca_gpio->gc.get_direction = ljca_gpio_get_direction;
431	ljca_gpio->gc.get = ljca_gpio_get_value;
432	ljca_gpio->gc.set = ljca_gpio_set_value;
433	ljca_gpio->gc.set_config = ljca_gpio_set_config;
434	ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
435	ljca_gpio->gc.can_sleep = true;
436	ljca_gpio->gc.parent = &auxdev->dev;
437
438	ljca_gpio->gc.base = -1;
439	ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
440	ljca_gpio->gc.label = ACPI_COMPANION(&auxdev->dev) ?
441			      acpi_dev_name(ACPI_COMPANION(&auxdev->dev)) :
442			      dev_name(&auxdev->dev);
443	ljca_gpio->gc.owner = THIS_MODULE;
444
445	auxiliary_set_drvdata(auxdev, ljca_gpio);
446	ljca_register_event_cb(ljca, ljca_gpio_event_cb, ljca_gpio);
447
448	girq = &ljca_gpio->gc.irq;
449	gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
450	girq->parent_handler = NULL;
451	girq->num_parents = 0;
452	girq->parents = NULL;
453	girq->default_type = IRQ_TYPE_NONE;
454	girq->handler = handle_simple_irq;
455	girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;
456
457	INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
458	ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
459	if (ret)
460		ljca_unregister_event_cb(ljca);
461
462	return ret;
463}
464
465static void ljca_gpio_remove(struct auxiliary_device *auxdev)
466{
467	struct ljca_gpio_dev *ljca_gpio = auxiliary_get_drvdata(auxdev);
468
469	gpiochip_remove(&ljca_gpio->gc);
470	ljca_unregister_event_cb(ljca_gpio->ljca);
471	cancel_work_sync(&ljca_gpio->work);
472}
473
474static const struct auxiliary_device_id ljca_gpio_id_table[] = {
475	{ "usb_ljca.ljca-gpio", 0 },
476	{ /* sentinel */ },
477};
478MODULE_DEVICE_TABLE(auxiliary, ljca_gpio_id_table);
479
480static struct auxiliary_driver ljca_gpio_driver = {
481	.probe = ljca_gpio_probe,
482	.remove = ljca_gpio_remove,
483	.id_table = ljca_gpio_id_table,
484};
485module_auxiliary_driver(ljca_gpio_driver);
486
487MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
488MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
489MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
490MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
491MODULE_LICENSE("GPL");
492MODULE_IMPORT_NS("LJCA");