107  * GPIO line handle management
276 		 * All line descriptors were created at once with the same  in linehandle_ioctl_unlocked()
407 		 * or output, else the line will be treated "as is".  in linehandle_create()
423 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",  in linehandle_create()
469  * struct line - contains the state of a requested line
471  * @desc: the GPIO descriptor for this line.
472  * @req: the corresponding line request
479  * events for the corresponding line request. This is drawn from the @req.
481  * events for this line.
485  * @level: the current debounced physical level of the line
487  * @raw_level: the line level at the time of event
491 struct line {  struct
550 	 * HTE provider sets line level at the time of event. The valid  argument
555 	 * when sw_debounce is set on HTE enabled line, this is running  argument
560 	 * when sw_debounce is set on HTE enabled line, this variable records  argument
571  * A line is determined to contain supplemental information by  argument
579  * struct linereq - contains the state of a userspace line request
580  * @gdev: the GPIO device the line request pertains to
588  * this line request.  Note that this is not used when @num_lines is 1, as
593  * @lines: the lines held by this line request, with @num_lines elements.
605 	struct line lines[];
608 static void supinfo_insert(struct line *line)  in supinfo_insert()  argument
611 	struct line *entry;  in supinfo_insert()
616 		entry = container_of(*new, struct line, node);  in supinfo_insert()
619 		if (line->desc < entry->desc) {  in supinfo_insert()
621 		} else if (line->desc > entry->desc) {  in supinfo_insert()
625 			WARN(1, "duplicate line inserted");  in supinfo_insert()
630 	rb_link_node(&line->node, parent, new);  in supinfo_insert()
631 	rb_insert_color(&line->node, &supinfo_tree);  in supinfo_insert()
634 static void supinfo_erase(struct line *line)  in supinfo_erase()  argument
638 	rb_erase(&line->node, &supinfo_tree);  in supinfo_erase()
641 static struct line *supinfo_find(struct gpio_desc *desc)  in supinfo_find()
644 	struct line *line;  in supinfo_find()  local
647 		line = container_of(node, struct line, node);  in supinfo_find()
648 		if (desc < line->desc)  in supinfo_find()
650 		else if (desc > line->desc)  in supinfo_find()
653 			return line;  in supinfo_find()
662 	struct line *line;  in supinfo_to_lineinfo()  local
666 	line = supinfo_find(desc);  in supinfo_to_lineinfo()
667 	if (!line)  in supinfo_to_lineinfo()
672 	attr->debounce_period_us = READ_ONCE(line->debounce_period_us);  in supinfo_to_lineinfo()
676 static inline bool line_has_supinfo(struct line *line)  in line_has_supinfo()  argument
678 	return READ_ONCE(line->debounce_period_us);  in line_has_supinfo()
684  * Called indirectly by linereq_create() or linereq_set_config() so line
687 static void line_set_debounce_period(struct line *line,  in line_set_debounce_period()  argument
690 	bool was_suppl = line_has_supinfo(line);  in line_set_debounce_period()
692 	WRITE_ONCE(line->debounce_period_us, debounce_period_us);  in line_set_debounce_period()
695 	if (line_has_supinfo(line) == was_suppl)  in line_set_debounce_period()
700 		supinfo_erase(line);  in line_set_debounce_period()
702 		supinfo_insert(line);  in line_set_debounce_period()
768 static u64 line_event_timestamp(struct line *line)  in line_event_timestamp()  argument
770 	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags))  in line_event_timestamp()
773 		 test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))  in line_event_timestamp()
774 		return line->timestamp_ns;  in line_event_timestamp()
808 	struct line *line;  in process_hw_ts_thread()  local
817 	line = p;  in process_hw_ts_thread()
818 	lr = line->req;  in process_hw_ts_thread()
822 	le.timestamp_ns = line->timestamp_ns;  in process_hw_ts_thread()
823 	edflags = READ_ONCE(line->edflags);  in process_hw_ts_thread()
827 		level = (line->raw_level >= 0) ?  in process_hw_ts_thread()
828 				line->raw_level :  in process_hw_ts_thread()
829 				gpiod_get_raw_value_cansleep(line->desc);  in process_hw_ts_thread()
845 	le.line_seqno = line->line_seqno;  in process_hw_ts_thread()
846 	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;  in process_hw_ts_thread()
847 	le.offset = gpio_chip_hwgpio(line->desc);  in process_hw_ts_thread()
856 	struct line *line;  in process_hw_ts()  local
863 	line = p;  in process_hw_ts()
864 	line->timestamp_ns = ts->tsc;  in process_hw_ts()
865 	line->raw_level = ts->raw_level;  in process_hw_ts()
866 	lr = line->req;  in process_hw_ts()
868 	if (READ_ONCE(line->sw_debounced)) {  in process_hw_ts()
869 		line->total_discard_seq++;  in process_hw_ts()
870 		line->last_seqno = ts->seq;  in process_hw_ts()
871 		mod_delayed_work(system_wq, &line->work,  in process_hw_ts()
872 		  usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));  in process_hw_ts()
874 		if (unlikely(ts->seq < line->line_seqno))  in process_hw_ts()
877 		diff_seqno = ts->seq - line->line_seqno;  in process_hw_ts()
878 		line->line_seqno = ts->seq;  in process_hw_ts()
880 			line->req_seqno = atomic_add_return(diff_seqno,  in process_hw_ts()
889 static int hte_edge_setup(struct line *line, u64 eflags)  in hte_edge_setup()  argument
893 	struct hte_ts_desc *hdesc = &line->hdesc;  in hte_edge_setup()
896 		flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in hte_edge_setup()
900 		flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in hte_edge_setup()
904 	line->total_discard_seq = 0;  in hte_edge_setup()
906 	hte_init_line_attr(hdesc, desc_to_gpio(line->desc), flags, NULL,  in hte_edge_setup()
907 			   line->desc);  in hte_edge_setup()
914 				 line);  in hte_edge_setup()
919 static int hte_edge_setup(struct line *line, u64 eflags)  in hte_edge_setup()  argument
927 	struct line *line = p;  in edge_irq_thread()  local
928 	struct linereq *lr = line->req;  in edge_irq_thread()
934 	if (line->timestamp_ns) {  in edge_irq_thread()
935 		le.timestamp_ns = line->timestamp_ns;  in edge_irq_thread()
942 		le.timestamp_ns = line_event_timestamp(line);  in edge_irq_thread()
944 			line->req_seqno = atomic_inc_return(&lr->seqno);  in edge_irq_thread()
946 	line->timestamp_ns = 0;  in edge_irq_thread()
948 	switch (READ_ONCE(line->edflags) & GPIO_V2_LINE_EDGE_FLAGS) {  in edge_irq_thread()
950 		le.id = line_event_id(gpiod_get_value_cansleep(line->desc));  in edge_irq_thread()
961 	line->line_seqno++;  in edge_irq_thread()
962 	le.line_seqno = line->line_seqno;  in edge_irq_thread()
963 	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;  in edge_irq_thread()
964 	le.offset = gpio_chip_hwgpio(line->desc);  in edge_irq_thread()
973 	struct line *line = p;  in edge_irq_handler()  local
974 	struct linereq *lr = line->req;  in edge_irq_handler()
980 	line->timestamp_ns = line_event_timestamp(line);  in edge_irq_handler()
983 		line->req_seqno = atomic_inc_return(&lr->seqno);  in edge_irq_handler()
991 static bool debounced_value(struct line *line)  in debounced_value()  argument
1000 	value = READ_ONCE(line->level);  in debounced_value()
1002 	if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))  in debounced_value()
1010 	struct line *line = p;  in debounce_irq_handler()  local
1012 	mod_delayed_work(system_wq, &line->work,  in debounce_irq_handler()
1013 		usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));  in debounce_irq_handler()
1021 	struct line *line = container_of(work, struct line, work.work);  in debounce_work_func()  local
1023 	u64 eflags, edflags = READ_ONCE(line->edflags);  in debounce_work_func()
1029 		level = line->raw_level;  in debounce_work_func()
1032 		level = gpiod_get_raw_value_cansleep(line->desc);  in debounce_work_func()
1034 		pr_debug_ratelimited("debouncer failed to read line value\n");  in debounce_work_func()
1038 	if (READ_ONCE(line->level) == level)  in debounce_work_func()
1041 	WRITE_ONCE(line->level, level);  in debounce_work_func()
1060 	lr = line->req;  in debounce_work_func()
1061 	le.timestamp_ns = line_event_timestamp(line);  in debounce_work_func()
1062 	le.offset = gpio_chip_hwgpio(line->desc);  in debounce_work_func()
1066 		line->total_discard_seq -= 1;  in debounce_work_func()
1067 		diff_seqno = line->last_seqno - line->total_discard_seq -  in debounce_work_func()
1068 				line->line_seqno;  in debounce_work_func()
1069 		line->line_seqno = line->last_seqno - line->total_discard_seq;  in debounce_work_func()
1070 		le.line_seqno = line->line_seqno;  in debounce_work_func()
1076 		line->line_seqno++;  in debounce_work_func()
1077 		le.line_seqno = line->line_seqno;  in debounce_work_func()
1087 static int debounce_setup(struct line *line, unsigned int debounce_period_us)  in debounce_setup()  argument
1094 	ret = gpiod_set_debounce(line->desc, debounce_period_us);  in debounce_setup()
1096 		line_set_debounce_period(line, debounce_period_us);  in debounce_setup()
1104 		level = gpiod_get_raw_value_cansleep(line->desc);  in debounce_setup()
1109 		      test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))) {  in debounce_setup()
1110 			irq = gpiod_to_irq(line->desc);  in debounce_setup()
1114 			label = make_irq_label(line->req->label);  in debounce_setup()
1120 					  label, line);  in debounce_setup()
1125 			line->irq = irq;  in debounce_setup()
1127 			ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH);  in debounce_setup()
1132 		WRITE_ONCE(line->level, level);  in debounce_setup()
1133 		WRITE_ONCE(line->sw_debounced, 1);  in debounce_setup()
1166 static void edge_detector_stop(struct line *line)  in edge_detector_stop()  argument
1168 	if (line->irq) {  in edge_detector_stop()
1169 		free_irq_label(free_irq(line->irq, line));  in edge_detector_stop()
1170 		line->irq = 0;  in edge_detector_stop()
1174 	if (READ_ONCE(line->edflags) & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)  in edge_detector_stop()
1175 		hte_ts_put(&line->hdesc);  in edge_detector_stop()
1178 	cancel_delayed_work_sync(&line->work);  in edge_detector_stop()
1179 	WRITE_ONCE(line->sw_debounced, 0);  in edge_detector_stop()
1180 	WRITE_ONCE(line->edflags, 0);  in edge_detector_stop()
1181 	line_set_debounce_period(line, 0);  in edge_detector_stop()
1182 	/* do not change line->level - see comment in debounced_value() */  in edge_detector_stop()
1185 static int edge_detector_setup(struct line *line,  in edge_detector_setup()  argument
1196 	if (eflags && !kfifo_initialized(&line->req->events)) {  in edge_detector_setup()
1197 		ret = kfifo_alloc(&line->req->events,  in edge_detector_setup()
1198 				  line->req->event_buffer_size, GFP_KERNEL);  in edge_detector_setup()
1204 		ret = debounce_setup(line, debounce_period_us);  in edge_detector_setup()
1207 		line_set_debounce_period(line, debounce_period_us);  in edge_detector_setup()
1211 	if (!eflags || READ_ONCE(line->sw_debounced))  in edge_detector_setup()
1216 		return hte_edge_setup(line, edflags);  in edge_detector_setup()
1218 	irq = gpiod_to_irq(line->desc);  in edge_detector_setup()
1223 		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in edge_detector_setup()
1226 		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in edge_detector_setup()
1230 	label = make_irq_label(line->req->label);  in edge_detector_setup()
1236 				   irqflags, label, line);  in edge_detector_setup()
1242 	line->irq = irq;  in edge_detector_setup()
1246 static int edge_detector_update(struct line *line,  in edge_detector_update()  argument
1252 	u64 active_edflags = READ_ONCE(line->edflags);  in edge_detector_update()
1257 	    (READ_ONCE(line->debounce_period_us) == debounce_period_us))  in edge_detector_update()
1261 	if (debounce_period_us && READ_ONCE(line->sw_debounced)) {  in edge_detector_update()
1262 		line_set_debounce_period(line, debounce_period_us);  in edge_detector_update()
1268 		if (eflags && !kfifo_initialized(&line->req->events)) {  in edge_detector_update()
1269 			ret = kfifo_alloc(&line->req->events,  in edge_detector_update()
1270 					  line->req->event_buffer_size,  in edge_detector_update()
1279 	if ((line->irq && !READ_ONCE(line->sw_debounced)) ||  in edge_detector_update()
1281 	    (!debounce_period_us && READ_ONCE(line->sw_debounced)))  in edge_detector_update()
1282 		edge_detector_stop(line);  in edge_detector_update()
1284 	return edge_detector_setup(line, lc, line_idx, edflags);  in edge_detector_update()
1559 	struct line *line;  in linereq_set_config_unlocked()  local
1565 		line = &lr->lines[i];  in linereq_set_config_unlocked()
1579 			edge_detector_stop(line);  in linereq_set_config_unlocked()
1588 			ret = edge_detector_update(line, lc, i, edflags);  in linereq_set_config_unlocked()
1593 		WRITE_ONCE(line->edflags, edflags);  in linereq_set_config_unlocked()
1751 	struct line *line;  in linereq_free()  local
1759 		line = &lr->lines[i];  in linereq_free()
1760 		if (!line->desc)  in linereq_free()
1763 		edge_detector_stop(line);  in linereq_free()
1764 		if (line_has_supinfo(line))  in linereq_free()
1765 			supinfo_erase(line);  in linereq_free()
1766 		gpiod_free(line->desc);  in linereq_free()
1792 		seq_printf(out, "gpio-line:\t%d\n",  in linereq_show_fdinfo()
1894 		 * or output, else the line will be treated "as is".  in linereq_create()
1917 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",  in linereq_create()
1933 	file = anon_inode_getfile("gpio-line", &line_fileops, lr,  in linereq_create()
1968  * GPIO line event management
1976  * @eflags: the event flags this line was requested with
2151 	 * We can get the value for an event line but not set it,  in lineevent_ioctl_unlocked()