64  * GPIO line handle management
235 		 * All line descriptors were created at once with the same  in linehandle_ioctl()
357 		 * or output, else the line will be treated "as is".  in linehandle_create()
373 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",  in linehandle_create()
419  * struct line - contains the state of a requested line
421  * @desc: the GPIO descriptor for this line.
422  * @req: the corresponding line request
429  * events for the corresponding line request. This is drawn from the @req.
431  * events for this line.
435  * @level: the current debounced physical level of the line
437  * @raw_level: the line level at the time of event
441 struct line {  struct
500 	 * HTE provider sets line level at the time of event. The valid  argument
505 	 * when sw_debounce is set on HTE enabled line, this is running  argument
510 	 * when sw_debounce is set on HTE enabled line, this variable records  argument
521  * A line is determined to contain supplemental information by  argument
529  * struct linereq - contains the state of a userspace line request
530  * @gdev: the GPIO device the line request pertains to
538  * this line request.  Note that this is not used when @num_lines is 1, as
543  * @lines: the lines held by this line request, with @num_lines elements.
555 	struct line lines[] __counted_by(num_lines);
558 static void supinfo_insert(struct line *line)  in supinfo_insert()  argument
561 	struct line *entry;  in supinfo_insert()
566 		entry = container_of(*new, struct line, node);  in supinfo_insert()
569 		if (line->desc < entry->desc) {  in supinfo_insert()
571 		} else if (line->desc > entry->desc) {  in supinfo_insert()
575 			WARN(1, "duplicate line inserted");  in supinfo_insert()
580 	rb_link_node(&line->node, parent, new);  in supinfo_insert()
581 	rb_insert_color(&line->node, &supinfo_tree);  in supinfo_insert()
584 static void supinfo_erase(struct line *line)  in supinfo_erase()  argument
588 	rb_erase(&line->node, &supinfo_tree);  in supinfo_erase()
591 static struct line *supinfo_find(struct gpio_desc *desc)  in supinfo_find()
594 	struct line *line;  in supinfo_find()  local
597 		line = container_of(node, struct line, node);  in supinfo_find()
598 		if (desc < line->desc)  in supinfo_find()
600 		else if (desc > line->desc)  in supinfo_find()
603 			return line;  in supinfo_find()
612 	struct line *line;  in supinfo_to_lineinfo()  local
616 	line = supinfo_find(desc);  in supinfo_to_lineinfo()
617 	if (!line)  in supinfo_to_lineinfo()
622 	attr->debounce_period_us = READ_ONCE(line->debounce_period_us);  in supinfo_to_lineinfo()
626 static inline bool line_has_supinfo(struct line *line)  in line_has_supinfo()  argument
628 	return READ_ONCE(line->debounce_period_us);  in line_has_supinfo()
634  * Called indirectly by linereq_create() or linereq_set_config() so line
637 static void line_set_debounce_period(struct line *line,  in line_set_debounce_period()  argument
640 	bool was_suppl = line_has_supinfo(line);  in line_set_debounce_period()
642 	WRITE_ONCE(line->debounce_period_us, debounce_period_us);  in line_set_debounce_period()
645 	if (line_has_supinfo(line) == was_suppl)  in line_set_debounce_period()
650 		supinfo_erase(line);  in line_set_debounce_period()
652 		supinfo_insert(line);  in line_set_debounce_period()
718 static u64 line_event_timestamp(struct line *line)  in line_event_timestamp()  argument
720 	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags))  in line_event_timestamp()
723 		 test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))  in line_event_timestamp()
724 		return line->timestamp_ns;  in line_event_timestamp()
758 	struct line *line;  in process_hw_ts_thread()  local
767 	line = p;  in process_hw_ts_thread()
768 	lr = line->req;  in process_hw_ts_thread()
772 	le.timestamp_ns = line->timestamp_ns;  in process_hw_ts_thread()
773 	edflags = READ_ONCE(line->edflags);  in process_hw_ts_thread()
777 		level = (line->raw_level >= 0) ?  in process_hw_ts_thread()
778 				line->raw_level :  in process_hw_ts_thread()
779 				gpiod_get_raw_value_cansleep(line->desc);  in process_hw_ts_thread()
795 	le.line_seqno = line->line_seqno;  in process_hw_ts_thread()
796 	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;  in process_hw_ts_thread()
797 	le.offset = gpio_chip_hwgpio(line->desc);  in process_hw_ts_thread()
806 	struct line *line;  in process_hw_ts()  local
813 	line = p;  in process_hw_ts()
814 	line->timestamp_ns = ts->tsc;  in process_hw_ts()
815 	line->raw_level = ts->raw_level;  in process_hw_ts()
816 	lr = line->req;  in process_hw_ts()
818 	if (READ_ONCE(line->sw_debounced)) {  in process_hw_ts()
819 		line->total_discard_seq++;  in process_hw_ts()
820 		line->last_seqno = ts->seq;  in process_hw_ts()
821 		mod_delayed_work(system_wq, &line->work,  in process_hw_ts()
822 		  usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));  in process_hw_ts()
824 		if (unlikely(ts->seq < line->line_seqno))  in process_hw_ts()
827 		diff_seqno = ts->seq - line->line_seqno;  in process_hw_ts()
828 		line->line_seqno = ts->seq;  in process_hw_ts()
830 			line->req_seqno = atomic_add_return(diff_seqno,  in process_hw_ts()
839 static int hte_edge_setup(struct line *line, u64 eflags)  in hte_edge_setup()  argument
843 	struct hte_ts_desc *hdesc = &line->hdesc;  in hte_edge_setup()
846 		flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in hte_edge_setup()
850 		flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in hte_edge_setup()
854 	line->total_discard_seq = 0;  in hte_edge_setup()
856 	hte_init_line_attr(hdesc, desc_to_gpio(line->desc), flags, NULL,  in hte_edge_setup()
857 			   line->desc);  in hte_edge_setup()
864 				 line);  in hte_edge_setup()
869 static int hte_edge_setup(struct line *line, u64 eflags)  in hte_edge_setup()  argument
877 	struct line *line = p;  in edge_irq_thread()  local
878 	struct linereq *lr = line->req;  in edge_irq_thread()
884 	if (line->timestamp_ns) {  in edge_irq_thread()
885 		le.timestamp_ns = line->timestamp_ns;  in edge_irq_thread()
892 		le.timestamp_ns = line_event_timestamp(line);  in edge_irq_thread()
894 			line->req_seqno = atomic_inc_return(&lr->seqno);  in edge_irq_thread()
896 	line->timestamp_ns = 0;  in edge_irq_thread()
898 	switch (READ_ONCE(line->edflags) & GPIO_V2_LINE_EDGE_FLAGS) {  in edge_irq_thread()
900 		le.id = line_event_id(gpiod_get_value_cansleep(line->desc));  in edge_irq_thread()
911 	line->line_seqno++;  in edge_irq_thread()
912 	le.line_seqno = line->line_seqno;  in edge_irq_thread()
913 	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;  in edge_irq_thread()
914 	le.offset = gpio_chip_hwgpio(line->desc);  in edge_irq_thread()
923 	struct line *line = p;  in edge_irq_handler()  local
924 	struct linereq *lr = line->req;  in edge_irq_handler()
930 	line->timestamp_ns = line_event_timestamp(line);  in edge_irq_handler()
933 		line->req_seqno = atomic_inc_return(&lr->seqno);  in edge_irq_handler()
941 static bool debounced_value(struct line *line)  in debounced_value()  argument
950 	value = READ_ONCE(line->level);  in debounced_value()
952 	if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))  in debounced_value()
960 	struct line *line = p;  in debounce_irq_handler()  local
962 	mod_delayed_work(system_wq, &line->work,  in debounce_irq_handler()
963 		usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));  in debounce_irq_handler()
971 	struct line *line = container_of(work, struct line, work.work);  in debounce_work_func()  local
973 	u64 eflags, edflags = READ_ONCE(line->edflags);  in debounce_work_func()
979 		level = line->raw_level;  in debounce_work_func()
982 		level = gpiod_get_raw_value_cansleep(line->desc);  in debounce_work_func()
984 		pr_debug_ratelimited("debouncer failed to read line value\n");  in debounce_work_func()
988 	if (READ_ONCE(line->level) == level)  in debounce_work_func()
991 	WRITE_ONCE(line->level, level);  in debounce_work_func()
1010 	lr = line->req;  in debounce_work_func()
1011 	le.timestamp_ns = line_event_timestamp(line);  in debounce_work_func()
1012 	le.offset = gpio_chip_hwgpio(line->desc);  in debounce_work_func()
1016 		line->total_discard_seq -= 1;  in debounce_work_func()
1017 		diff_seqno = line->last_seqno - line->total_discard_seq -  in debounce_work_func()
1018 				line->line_seqno;  in debounce_work_func()
1019 		line->line_seqno = line->last_seqno - line->total_discard_seq;  in debounce_work_func()
1020 		le.line_seqno = line->line_seqno;  in debounce_work_func()
1026 		line->line_seqno++;  in debounce_work_func()
1027 		le.line_seqno = line->line_seqno;  in debounce_work_func()
1037 static int debounce_setup(struct line *line, unsigned int debounce_period_us)  in debounce_setup()  argument
1044 	ret = gpiod_set_debounce(line->desc, debounce_period_us);  in debounce_setup()
1046 		line_set_debounce_period(line, debounce_period_us);  in debounce_setup()
1054 		level = gpiod_get_raw_value_cansleep(line->desc);  in debounce_setup()
1059 		      test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))) {  in debounce_setup()
1060 			irq = gpiod_to_irq(line->desc);  in debounce_setup()
1064 			label = make_irq_label(line->req->label);  in debounce_setup()
1070 					  label, line);  in debounce_setup()
1075 			line->irq = irq;  in debounce_setup()
1077 			ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH);  in debounce_setup()
1082 		WRITE_ONCE(line->level, level);  in debounce_setup()
1083 		WRITE_ONCE(line->sw_debounced, 1);  in debounce_setup()
1116 static void edge_detector_stop(struct line *line)  in edge_detector_stop()  argument
1118 	if (line->irq) {  in edge_detector_stop()
1119 		free_irq_label(free_irq(line->irq, line));  in edge_detector_stop()
1120 		line->irq = 0;  in edge_detector_stop()
1124 	if (READ_ONCE(line->edflags) & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)  in edge_detector_stop()
1125 		hte_ts_put(&line->hdesc);  in edge_detector_stop()
1128 	cancel_delayed_work_sync(&line->work);  in edge_detector_stop()
1129 	WRITE_ONCE(line->sw_debounced, 0);  in edge_detector_stop()
1130 	WRITE_ONCE(line->edflags, 0);  in edge_detector_stop()
1131 	line_set_debounce_period(line, 0);  in edge_detector_stop()
1132 	/* do not change line->level - see comment in debounced_value() */  in edge_detector_stop()
1143 static int edge_detector_setup(struct line *line,  in edge_detector_setup()  argument
1155 		ret = edge_detector_fifo_init(line->req);  in edge_detector_setup()
1161 		ret = debounce_setup(line, debounce_period_us);  in edge_detector_setup()
1164 		line_set_debounce_period(line, debounce_period_us);  in edge_detector_setup()
1168 	if (!eflags || READ_ONCE(line->sw_debounced))  in edge_detector_setup()
1173 		return hte_edge_setup(line, edflags);  in edge_detector_setup()
1175 	irq = gpiod_to_irq(line->desc);  in edge_detector_setup()
1180 		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in edge_detector_setup()
1183 		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in edge_detector_setup()
1187 	label = make_irq_label(line->req->label);  in edge_detector_setup()
1193 				   irqflags, label, line);  in edge_detector_setup()
1199 	line->irq = irq;  in edge_detector_setup()
1203 static int edge_detector_update(struct line *line,  in edge_detector_update()  argument
1207 	u64 active_edflags = READ_ONCE(line->edflags);  in edge_detector_update()
1212 	    (READ_ONCE(line->debounce_period_us) == debounce_period_us))  in edge_detector_update()
1216 	if (debounce_period_us && READ_ONCE(line->sw_debounced)) {  in edge_detector_update()
1217 		line_set_debounce_period(line, debounce_period_us);  in edge_detector_update()
1223 			return edge_detector_fifo_init(line->req);  in edge_detector_update()
1229 	if ((line->irq && !READ_ONCE(line->sw_debounced)) ||  in edge_detector_update()
1231 	    (!debounce_period_us && READ_ONCE(line->sw_debounced)))  in edge_detector_update()
1232 		edge_detector_stop(line);  in edge_detector_update()
1234 	return edge_detector_setup(line, lc, line_idx, edflags);  in edge_detector_update()
1519 	struct line *line;  in linereq_set_config()  local
1534 		line = &lr->lines[i];  in linereq_set_config()
1548 			edge_detector_stop(line);  in linereq_set_config()
1557 			ret = edge_detector_update(line, &lc, i, edflags);  in linereq_set_config()
1562 		WRITE_ONCE(line->edflags, edflags);  in linereq_set_config()
1672 	struct line *line;  in linereq_free()  local
1680 		line = &lr->lines[i];  in linereq_free()
1681 		if (!line->desc)  in linereq_free()
1684 		edge_detector_stop(line);  in linereq_free()
1685 		if (line_has_supinfo(line))  in linereq_free()
1686 			supinfo_erase(line);  in linereq_free()
1687 		gpiod_free(line->desc);  in linereq_free()
1713 		seq_printf(out, "gpio-line:\t%d\n",  in linereq_show_fdinfo()
1816 		 * or output, else the line will be treated "as is".  in linereq_create()
1839 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",  in linereq_create()
1855 	file = anon_inode_getfile("gpio-line", &line_fileops, lr,  in linereq_create()
1890  * GPIO line event management
1898  * @eflags: the event flags this line was requested with
2055 	 * We can get the value for an event line but not set it,  in lineevent_ioctl()
2385 	 * once.  Worst case if the line is in transition and the calculation  in gpio_desc_to_lineinfo()
2389 	 * The definitive test that a line is available to userspace is to  in gpio_desc_to_lineinfo()