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