Input: new driver for SGI O2 volume buttons

This driver adds support for the volume buttons on the front of every
SGI O2 workstation.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

3 files changed, 167 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 432699d61c58..e33d7cbcb1df 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -189,6 +189,16 @@ config INPUT_UINPUT
           To compile this driver as a module, choose M here: the
           module will be called uinput.
 
+config INPUT_SGIO2_BTNS
+        tristate "SGI O2 volume button interface"
+        depends on SGI_IP32
+        select INPUT_POLLDEV
+        help
+          Say Y here if you want to support SGI O2 volume button interface.
+
+          To compile this driver as a module, choose M here: the
+          module will be called sgio_btns.
+
 config HP_SDC_RTC
         tristate "HP SDC Real Time Clock"
         depends on GSC || HP300
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index ebd39f291d25..0e274f19bcb3 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_INPUT_YEALINK)		+= yealink.o
 obj-$(CONFIG_HP_SDC_RTC)                += hp_sdc_rtc.o
 obj-$(CONFIG_INPUT_UINPUT)              += uinput.o
 obj-$(CONFIG_INPUT_APANEL)              += apanel.o
+obj-$(CONFIG_INPUT_SGIO2_BTNS)          += sgio2_btns.o
diff --git a/drivers/input/misc/sgio2_btns.c b/drivers/input/misc/sgio2_btns.c
new file mode 100644
index 000000000000..b1ab43d903dd
--- /dev/null
+++ b/drivers/input/misc/sgio2_btns.c
@@ -0,0 +1,156 @@
+/*
+ *  SGI O2 Volume Button interface driver
+ *
+ *  Copyright (C) 2008  Thomas Bogendoerfer <tsbogend@alpha.franken.de>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/init.h>
+#include <linux/input-polldev.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <asm/ip32/mace.h>
+
+#define BUTTONS_POLL_INTERVAL   30      /* msec */
+#define BUTTONS_COUNT_THRESHOLD 3
+
+static const unsigned short sgio2_map[] = {
+        KEY_VOLUMEUP,
+        KEY_VOLUMEDOWN
+};
+
+struct buttons_dev {
+        struct input_polled_dev *poll_dev;
+        unsigned short keymap[ARRAY_SIZE(sgio2_map)];
+        int count[ARRAY_SIZE(sgio2_map)];
+        void __iomem *reg;
+};
+
+static void handle_buttons(struct input_polled_dev *dev)
+{
+        struct buttons_dev *bdev = dev->private;
+        struct input_dev *input = dev->input;
+        u64 status;
+        int i;
+
+        status = (readq(&mace->perif.audio.control) >> 23) & 3;
+
+        for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) {
+                if (status & (1U << i)) {
+                        writeq(status & ~(1U << i), &mace->perif.audio.control);
+                        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 __devinit sgio2_buttons_probe(struct platform_device *pdev)
+{
+        struct buttons_dev *bdev;
+        struct input_polled_dev *poll_dev;
+        struct input_dev *input;
+        int error, i;
+
+        bdev = kzalloc(sizeof(struct buttons_dev), GFP_KERNEL);
+        poll_dev = input_allocate_polled_device();
+        if (!bdev || !poll_dev) {
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        memcpy(bdev->keymap, sgio2_map, sizeof(bdev->keymap));
+
+        poll_dev->private = bdev;
+        poll_dev->poll = handle_buttons;
+        poll_dev->poll_interval = BUTTONS_POLL_INTERVAL;
+
+        input = poll_dev->input;
+        input->name = "SGI O2 buttons";
+        input->phys = "sgio2/input0";
+        input->id.bustype = BUS_HOST;
+        input->dev.parent = &pdev->dev;
+
+        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(sgio2_map); i++)
+                __set_bit(bdev->keymap[i], input->keybit);
+        __clear_bit(KEY_RESERVED, input->keybit);
+
+        bdev->poll_dev = poll_dev;
+        dev_set_drvdata(&pdev->dev, bdev);
+
+        error = input_register_polled_device(poll_dev);
+        if (error)
+                goto err_free_mem;
+
+        return 0;
+
+ err_free_mem:
+        input_free_polled_device(poll_dev);
+        kfree(bdev);
+        dev_set_drvdata(&pdev->dev, NULL);
+        return error;
+}
+
+static int __devexit sgio2_buttons_remove(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct buttons_dev *bdev = dev_get_drvdata(dev);
+
+        input_unregister_polled_device(bdev->poll_dev);
+        input_free_polled_device(bdev->poll_dev);
+        kfree(bdev);
+        dev_set_drvdata(dev, NULL);
+
+        return 0;
+}
+
+static struct platform_driver sgio2_buttons_driver = {
+        .probe  = sgio2_buttons_probe,
+        .remove = __devexit_p(sgio2_buttons_remove),
+        .driver = {
+                .name   = "sgio2btns",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init sgio2_buttons_init(void)
+{
+        return platform_driver_register(&sgio2_buttons_driver);
+}
+
+static void __exit sgio2_buttons_exit(void)
+{
+        platform_driver_unregister(&sgio2_buttons_driver);
+}
+
+module_init(sgio2_buttons_init);
+module_exit(sgio2_buttons_exit);