1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/input/misc/sgi_btns.c b/drivers/input/misc/sgi_btns.c
new file mode 100644
index 0000000000..0657d785b3
--- /dev/null
+++ b/drivers/input/misc/sgi_btns.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  SGI Volume Button interface driver
+ *
+ *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+ */
+#include <linux/input.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_SGI_IP22
+#include <asm/sgi/ioc.h>
+
+static inline u8 button_status(void)
+{
+	u8 status;
+
+	status = readb(&sgioc->panel) ^ 0xa0;
+	return ((status & 0x80) >> 6) | ((status & 0x20) >> 5);
+}
+#endif
+
+#ifdef CONFIG_SGI_IP32
+#include <asm/ip32/mace.h>
+
+static inline u8 button_status(void)
+{
+	u64 status;
+
+	status = readq(&mace->perif.audio.control);
+	writeq(status & ~(3U << 23), &mace->perif.audio.control);
+
+	return (status >> 23) & 3;
+}
+#endif
+
+#define BUTTONS_POLL_INTERVAL	30	/* msec */
+#define BUTTONS_COUNT_THRESHOLD	3
+
+static const unsigned short sgi_map[] = {
+	KEY_VOLUMEDOWN,
+	KEY_VOLUMEUP
+};
+
+struct buttons_dev {
+	unsigned short keymap[ARRAY_SIZE(sgi_map)];
+	int count[ARRAY_SIZE(sgi_map)];
+};
+
+static void handle_buttons(struct input_dev *input)
+{
+	struct buttons_dev *bdev = input_get_drvdata(input);
+	u8 status;
+	int i;
+
+	status = button_status();
+
+	for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
+		if (status & (1U << i)) {
+			if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) {
+				input_event(input, EV_MSC, MSC_SCAN, i);
+				input_report_key(input, bdev->keymap[i], 1);
+				input_sync(input);
+			}
+		} else {
+			if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) {
+				input_event(input, EV_MSC, MSC_SCAN, i);
+				input_report_key(input, bdev->keymap[i], 0);
+				input_sync(input);
+			}
+			bdev->count[i] = 0;
+		}
+	}
+}
+
+static int sgi_buttons_probe(struct platform_device *pdev)
+{
+	struct buttons_dev *bdev;
+	struct input_dev *input;
+	int error, i;
+
+	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
+	if (!bdev)
+		return -ENOMEM;
+
+	input = devm_input_allocate_device(&pdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap));
+
+	input_set_drvdata(input, bdev);
+
+	input->name = "SGI buttons";
+	input->phys = "sgi/input0";
+	input->id.bustype = BUS_HOST;
+
+	input->keycode = bdev->keymap;
+	input->keycodemax = ARRAY_SIZE(bdev->keymap);
+	input->keycodesize = sizeof(unsigned short);
+
+	input_set_capability(input, EV_MSC, MSC_SCAN);
+	__set_bit(EV_KEY, input->evbit);
+	for (i = 0; i < ARRAY_SIZE(sgi_map); i++)
+		__set_bit(bdev->keymap[i], input->keybit);
+	__clear_bit(KEY_RESERVED, input->keybit);
+
+	error = input_setup_polling(input, handle_buttons);
+	if (error)
+		return error;
+
+	input_set_poll_interval(input, BUTTONS_POLL_INTERVAL);
+
+	error = input_register_device(input);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static struct platform_driver sgi_buttons_driver = {
+	.probe	= sgi_buttons_probe,
+	.driver	= {
+		.name	= "sgibtns",
+	},
+};
+module_platform_driver(sgi_buttons_driver);
+
+MODULE_LICENSE("GPL");