70  * GPIO line handle management
184 		 * or output, else the line will be treated "as is".  in linehandle_set_config()
237 		 * All line descriptors were created at once with the same  in linehandle_ioctl()
359 		 * or output, else the line will be treated "as is".  in linehandle_create()
375 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",  in linehandle_create()
421  * struct line - contains the state of a requested line
423  * @desc: the GPIO descriptor for this line.
424  * @req: the corresponding line request
431  * events for the corresponding line request. This is drawn from the @req.
433  * events for this line.
437  * @level: the current debounced physical level of the line
439  * @raw_level: the line level at the time of event
443 struct line {  struct
502 	 * HTE provider sets line level at the time of event. The valid  argument
507 	 * when sw_debounce is set on HTE enabled line, this is running  argument
512 	 * when sw_debounce is set on HTE enabled line, this variable records  argument
523  * A line is determined to contain supplemental information by  argument
531  * struct linereq - contains the state of a userspace line request
532  * @gdev: the GPIO device the line request pertains to
540  * this line request.  Note that this is not used when @num_lines is 1, as
545  * @lines: the lines held by this line request, with @num_lines elements.
557 	struct line lines[] __counted_by(num_lines);
560 static void supinfo_insert(struct line *line)  in supinfo_insert()  argument
563 	struct line *entry;  in supinfo_insert()
568 		entry = container_of(*new, struct line, node);  in supinfo_insert()
571 		if (line->desc < entry->desc) {  in supinfo_insert()
573 		} else if (line->desc > entry->desc) {  in supinfo_insert()
577 			WARN(1, "duplicate line inserted");  in supinfo_insert()
582 	rb_link_node(&line->node, parent, new);  in supinfo_insert()
583 	rb_insert_color(&line->node, &supinfo_tree);  in supinfo_insert()
586 static void supinfo_erase(struct line *line)  in supinfo_erase()  argument
590 	rb_erase(&line->node, &supinfo_tree);  in supinfo_erase()
593 static struct line *supinfo_find(struct gpio_desc *desc)  in supinfo_find()
596 	struct line *line;  in supinfo_find()  local
599 		line = container_of(node, struct line, node);  in supinfo_find()
600 		if (desc < line->desc)  in supinfo_find()
602 		else if (desc > line->desc)  in supinfo_find()
605 			return line;  in supinfo_find()
614 	struct line *line;  in supinfo_to_lineinfo()  local
618 	line = supinfo_find(desc);  in supinfo_to_lineinfo()
619 	if (!line)  in supinfo_to_lineinfo()
624 	attr->debounce_period_us = READ_ONCE(line->debounce_period_us);  in supinfo_to_lineinfo()
628 static inline bool line_has_supinfo(struct line *line)  in line_has_supinfo()  argument
630 	return READ_ONCE(line->debounce_period_us);  in line_has_supinfo()
636  * Called indirectly by linereq_create() or linereq_set_config() so line
639 static void line_set_debounce_period(struct line *line,  in line_set_debounce_period()  argument
642 	bool was_suppl = line_has_supinfo(line);  in line_set_debounce_period()
644 	WRITE_ONCE(line->debounce_period_us, debounce_period_us);  in line_set_debounce_period()
647 	if (line_has_supinfo(line) == was_suppl)  in line_set_debounce_period()
652 		supinfo_erase(line);  in line_set_debounce_period()
654 		supinfo_insert(line);  in line_set_debounce_period()
720 static u64 line_event_timestamp(struct line *line)  in line_event_timestamp()  argument
722 	if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags))  in line_event_timestamp()
725 		 test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))  in line_event_timestamp()
726 		return line->timestamp_ns;  in line_event_timestamp()
741 	struct line *line;  in process_hw_ts_thread()  local
750 	line = p;  in process_hw_ts_thread()
751 	lr = line->req;  in process_hw_ts_thread()
755 	le.timestamp_ns = line->timestamp_ns;  in process_hw_ts_thread()
756 	edflags = READ_ONCE(line->edflags);  in process_hw_ts_thread()
760 		level = (line->raw_level >= 0) ?  in process_hw_ts_thread()
761 				line->raw_level :  in process_hw_ts_thread()
762 				gpiod_get_raw_value_cansleep(line->desc);  in process_hw_ts_thread()
778 	le.line_seqno = line->line_seqno;  in process_hw_ts_thread()
779 	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;  in process_hw_ts_thread()
780 	le.offset = gpio_chip_hwgpio(line->desc);  in process_hw_ts_thread()
789 	struct line *line;  in process_hw_ts()  local
796 	line = p;  in process_hw_ts()
797 	line->timestamp_ns = ts->tsc;  in process_hw_ts()
798 	line->raw_level = ts->raw_level;  in process_hw_ts()
799 	lr = line->req;  in process_hw_ts()
801 	if (READ_ONCE(line->sw_debounced)) {  in process_hw_ts()
802 		line->total_discard_seq++;  in process_hw_ts()
803 		line->last_seqno = ts->seq;  in process_hw_ts()
804 		mod_delayed_work(system_wq, &line->work,  in process_hw_ts()
805 		  usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));  in process_hw_ts()
807 		if (unlikely(ts->seq < line->line_seqno))  in process_hw_ts()
810 		diff_seqno = ts->seq - line->line_seqno;  in process_hw_ts()
811 		line->line_seqno = ts->seq;  in process_hw_ts()
813 			line->req_seqno = atomic_add_return(diff_seqno,  in process_hw_ts()
822 static int hte_edge_setup(struct line *line, u64 eflags)  in hte_edge_setup()  argument
826 	struct hte_ts_desc *hdesc = &line->hdesc;  in hte_edge_setup()
829 		flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in hte_edge_setup()
833 		flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in hte_edge_setup()
837 	line->total_discard_seq = 0;  in hte_edge_setup()
839 	hte_init_line_attr(hdesc, desc_to_gpio(line->desc), flags, NULL,  in hte_edge_setup()
840 			   line->desc);  in hte_edge_setup()
847 				 line);  in hte_edge_setup()
852 static int hte_edge_setup(struct line *line, u64 eflags)  in hte_edge_setup()  argument
860 	struct line *line = p;  in edge_irq_thread()  local
861 	struct linereq *lr = line->req;  in edge_irq_thread()
867 	if (line->timestamp_ns) {  in edge_irq_thread()
868 		le.timestamp_ns = line->timestamp_ns;  in edge_irq_thread()
875 		le.timestamp_ns = line_event_timestamp(line);  in edge_irq_thread()
877 			line->req_seqno = atomic_inc_return(&lr->seqno);  in edge_irq_thread()
879 	line->timestamp_ns = 0;  in edge_irq_thread()
881 	switch (READ_ONCE(line->edflags) & GPIO_V2_LINE_EDGE_FLAGS) {  in edge_irq_thread()
883 		le.id = line_event_id(gpiod_get_value_cansleep(line->desc));  in edge_irq_thread()
894 	line->line_seqno++;  in edge_irq_thread()
895 	le.line_seqno = line->line_seqno;  in edge_irq_thread()
896 	le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno;  in edge_irq_thread()
897 	le.offset = gpio_chip_hwgpio(line->desc);  in edge_irq_thread()
906 	struct line *line = p;  in edge_irq_handler()  local
907 	struct linereq *lr = line->req;  in edge_irq_handler()
913 	line->timestamp_ns = line_event_timestamp(line);  in edge_irq_handler()
916 		line->req_seqno = atomic_inc_return(&lr->seqno);  in edge_irq_handler()
924 static bool debounced_value(struct line *line)  in debounced_value()  argument
933 	value = READ_ONCE(line->level);  in debounced_value()
935 	if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags))  in debounced_value()
943 	struct line *line = p;  in debounce_irq_handler()  local
945 	mod_delayed_work(system_wq, &line->work,  in debounce_irq_handler()
946 		usecs_to_jiffies(READ_ONCE(line->debounce_period_us)));  in debounce_irq_handler()
954 	struct line *line = container_of(work, struct line, work.work);  in debounce_work_func()  local
956 	u64 eflags, edflags = READ_ONCE(line->edflags);  in debounce_work_func()
962 		level = line->raw_level;  in debounce_work_func()
965 		level = gpiod_get_raw_value_cansleep(line->desc);  in debounce_work_func()
967 		pr_debug_ratelimited("debouncer failed to read line value\n");  in debounce_work_func()
971 	if (READ_ONCE(line->level) == level)  in debounce_work_func()
974 	WRITE_ONCE(line->level, level);  in debounce_work_func()
993 	lr = line->req;  in debounce_work_func()
994 	le.timestamp_ns = line_event_timestamp(line);  in debounce_work_func()
995 	le.offset = gpio_chip_hwgpio(line->desc);  in debounce_work_func()
999 		line->total_discard_seq -= 1;  in debounce_work_func()
1000 		diff_seqno = line->last_seqno - line->total_discard_seq -  in debounce_work_func()
1001 				line->line_seqno;  in debounce_work_func()
1002 		line->line_seqno = line->last_seqno - line->total_discard_seq;  in debounce_work_func()
1003 		le.line_seqno = line->line_seqno;  in debounce_work_func()
1009 		line->line_seqno++;  in debounce_work_func()
1010 		le.line_seqno = line->line_seqno;  in debounce_work_func()
1020 static int debounce_setup(struct line *line, unsigned int debounce_period_us)  in debounce_setup()  argument
1026 	ret = gpiod_set_debounce(line->desc, debounce_period_us);  in debounce_setup()
1028 		line_set_debounce_period(line, debounce_period_us);  in debounce_setup()
1036 		level = gpiod_get_raw_value_cansleep(line->desc);  in debounce_setup()
1041 		      test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))) {  in debounce_setup()
1042 			irq = gpiod_to_irq(line->desc);  in debounce_setup()
1048 					  line->req->label, line);  in debounce_setup()
1051 			line->irq = irq;  in debounce_setup()
1053 			ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH);  in debounce_setup()
1058 		WRITE_ONCE(line->level, level);  in debounce_setup()
1059 		WRITE_ONCE(line->sw_debounced, 1);  in debounce_setup()
1092 static void edge_detector_stop(struct line *line)  in edge_detector_stop()  argument
1094 	if (line->irq) {  in edge_detector_stop()
1095 		free_irq(line->irq, line);  in edge_detector_stop()
1096 		line->irq = 0;  in edge_detector_stop()
1100 	if (READ_ONCE(line->edflags) & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)  in edge_detector_stop()
1101 		hte_ts_put(&line->hdesc);  in edge_detector_stop()
1104 	cancel_delayed_work_sync(&line->work);  in edge_detector_stop()
1105 	WRITE_ONCE(line->sw_debounced, 0);  in edge_detector_stop()
1106 	WRITE_ONCE(line->edflags, 0);  in edge_detector_stop()
1107 	line_set_debounce_period(line, 0);  in edge_detector_stop()
1108 	/* do not change line->level - see comment in debounced_value() */  in edge_detector_stop()
1111 static int edge_detector_setup(struct line *line,  in edge_detector_setup()  argument
1121 	if (eflags && !kfifo_initialized(&line->req->events)) {  in edge_detector_setup()
1122 		ret = kfifo_alloc(&line->req->events,  in edge_detector_setup()
1123 				  line->req->event_buffer_size, GFP_KERNEL);  in edge_detector_setup()
1129 		ret = debounce_setup(line, debounce_period_us);  in edge_detector_setup()
1132 		line_set_debounce_period(line, debounce_period_us);  in edge_detector_setup()
1136 	if (!eflags || READ_ONCE(line->sw_debounced))  in edge_detector_setup()
1141 		return hte_edge_setup(line, edflags);  in edge_detector_setup()
1143 	irq = gpiod_to_irq(line->desc);  in edge_detector_setup()
1148 		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in edge_detector_setup()
1151 		irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ?  in edge_detector_setup()
1157 				   irqflags, line->req->label, line);  in edge_detector_setup()
1161 	line->irq = irq;  in edge_detector_setup()
1165 static int edge_detector_update(struct line *line,  in edge_detector_update()  argument
1169 	u64 active_edflags = READ_ONCE(line->edflags);  in edge_detector_update()
1174 	    (READ_ONCE(line->debounce_period_us) == debounce_period_us))  in edge_detector_update()
1178 	if (debounce_period_us && READ_ONCE(line->sw_debounced)) {  in edge_detector_update()
1179 		line_set_debounce_period(line, debounce_period_us);  in edge_detector_update()
1184 	if ((line->irq && !READ_ONCE(line->sw_debounced)) ||  in edge_detector_update()
1186 	    (!debounce_period_us && READ_ONCE(line->sw_debounced)))  in edge_detector_update()
1187 		edge_detector_stop(line);  in edge_detector_update()
1189 	return edge_detector_setup(line, lc, line_idx, edflags);  in edge_detector_update()
1474 	struct line *line;  in linereq_set_config()  local
1489 		line = &lr->lines[i];  in linereq_set_config()
1496 		 * or output, else the line will be treated "as is".  in linereq_set_config()
1501 			edge_detector_stop(line);  in linereq_set_config()
1510 			ret = edge_detector_update(line, &lc, i, edflags);  in linereq_set_config()
1515 		WRITE_ONCE(line->edflags, edflags);  in linereq_set_config()
1626 	struct line *line;  in linereq_free()  local
1634 		line = &lr->lines[i];  in linereq_free()
1635 		if (!line->desc)  in linereq_free()
1638 		edge_detector_stop(line);  in linereq_free()
1639 		if (line_has_supinfo(line))  in linereq_free()
1640 			supinfo_erase(line);  in linereq_free()
1641 		gpiod_free(line->desc);  in linereq_free()
1667 		seq_printf(out, "gpio-line:\t%d\n",  in linereq_show_fdinfo()
1769 		 * or output, else the line will be treated "as is".  in linereq_create()
1792 		dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",  in linereq_create()
1808 	file = anon_inode_getfile("gpio-line", &line_fileops, lr,  in linereq_create()
1843  * GPIO line event management
1851  * @eflags: the event flags this line was requested with
2009 	 * We can get the value for an event line but not set it,  in lineevent_ioctl()
2325 	 * once.  Worst case if the line is in transition and the calculation  in gpio_desc_to_lineinfo()
2329 	 * The definitive test that a line is available to userspace is to  in gpio_desc_to_lineinfo()