input: Add support for the WM831x ON pin

The WM831x series of PMICs support control of initial power on
through the ON pin on the device with soft control of the pin
at other times. Represent this to userspace as KEY_POWER.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 174 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index cbe21bc96b52..852941d108ff 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -279,4 +279,14 @@ config INPUT_BFIN_ROTARY
           To compile this driver as a module, choose M here: the
           module will be called bfin-rotary.
 
+config INPUT_WM831X_ON
+        tristate "WM831X ON pin"
+        depends on MFD_WM831X
+        help
+          Support the ON pin of WM831X PMICs as an input device
+          reporting power button status.
+
+          To compile this driver as a module, choose M here: the module
+          will be called wm831x_on.
+
 endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 79c1e9a5ea31..c97533fb83c8 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -26,4 +26,5 @@ obj-$(CONFIG_INPUT_SPARCSPKR)		+= sparcspkr.o
 obj-$(CONFIG_INPUT_TWL4030_PWRBUTTON)   += twl4030-pwrbutton.o
 obj-$(CONFIG_INPUT_UINPUT)              += uinput.o
 obj-$(CONFIG_INPUT_WISTRON_BTNS)        += wistron_btns.o
+obj-$(CONFIG_INPUT_WM831X_ON)           += wm831x-on.o
 obj-$(CONFIG_INPUT_YEALINK)             += yealink.o
diff --git a/drivers/input/misc/wm831x-on.c b/drivers/input/misc/wm831x-on.c
new file mode 100644
index 000000000000..ba4f5dd7c60e
--- /dev/null
+++ b/drivers/input/misc/wm831x-on.c
@@ -0,0 +1,163 @@
+/**
+ * wm831x-on.c - WM831X ON pin driver
+ *
+ * Copyright (C) 2009 Wolfson Microelectronics plc
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <linux/mfd/wm831x/core.h>
+
+struct wm831x_on {
+        struct input_dev *dev;
+        struct delayed_work work;
+        struct wm831x *wm831x;
+};
+
+/*
+ * The chip gives us an interrupt when the ON pin is asserted but we
+ * then need to poll to see when the pin is deasserted.
+ */
+static void wm831x_poll_on(struct work_struct *work)
+{
+        struct wm831x_on *wm831x_on = container_of(work, struct wm831x_on,
+                                                   work.work);
+        struct wm831x *wm831x = wm831x_on->wm831x;
+        int poll, ret;
+
+        ret = wm831x_reg_read(wm831x, WM831X_ON_PIN_CONTROL);
+        if (ret >= 0) {
+                poll = !(ret & WM831X_ON_PIN_STS);
+
+                input_report_key(wm831x_on->dev, KEY_POWER, poll);
+                input_sync(wm831x_on->dev);
+        } else {
+                dev_err(wm831x->dev, "Failed to read ON status: %d\n", ret);
+                poll = 1;
+        }
+
+        if (poll)
+                schedule_delayed_work(&wm831x_on->work, 100);
+}
+
+static irqreturn_t wm831x_on_irq(int irq, void *data)
+{
+        struct wm831x_on *wm831x_on = data;
+
+        schedule_delayed_work(&wm831x_on->work, 0);
+
+        return IRQ_HANDLED;
+}
+
+static int __devinit wm831x_on_probe(struct platform_device *pdev)
+{
+        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+        struct wm831x_on *wm831x_on;
+        int irq = platform_get_irq(pdev, 0);
+        int ret;
+
+        wm831x_on = kzalloc(sizeof(struct wm831x_on), GFP_KERNEL);
+        if (!wm831x_on) {
+                dev_err(&pdev->dev, "Can't allocate data\n");
+                return -ENOMEM;
+        }
+
+        wm831x_on->wm831x = wm831x;
+        INIT_DELAYED_WORK(&wm831x_on->work, wm831x_poll_on);
+
+        wm831x_on->dev = input_allocate_device();
+        if (!wm831x_on->dev) {
+                dev_err(&pdev->dev, "Can't allocate input dev\n");
+                ret = -ENOMEM;
+                goto err;
+        }
+
+        wm831x_on->dev->evbit[0] = BIT_MASK(EV_KEY);
+        wm831x_on->dev->keybit[BIT_WORD(KEY_POWER)] = BIT_MASK(KEY_POWER);
+        wm831x_on->dev->name = "wm831x_on";
+        wm831x_on->dev->phys = "wm831x_on/input0";
+        wm831x_on->dev->dev.parent = &pdev->dev;
+
+        ret = wm831x_request_irq(wm831x, irq, wm831x_on_irq,
+                                 IRQF_TRIGGER_RISING, "wm831x_on", wm831x_on);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Unable to request IRQ: %d\n", ret);
+                goto err_input_dev;
+        }
+        ret = input_register_device(wm831x_on->dev);
+        if (ret) {
+                dev_dbg(&pdev->dev, "Can't register input device: %d\n", ret);
+                goto err_irq;
+        }
+
+        platform_set_drvdata(pdev, wm831x_on);
+
+        return 0;
+
+err_irq:
+        wm831x_free_irq(wm831x, irq, NULL);
+err_input_dev:
+        input_free_device(wm831x_on->dev);
+err:
+        kfree(wm831x_on);
+        return ret;
+}
+
+static int __devexit wm831x_on_remove(struct platform_device *pdev)
+{
+        struct wm831x_on *wm831x_on = platform_get_drvdata(pdev);
+        int irq = platform_get_irq(pdev, 0);
+
+        wm831x_free_irq(wm831x_on->wm831x, irq, wm831x_on);
+        cancel_delayed_work_sync(&wm831x_on->work);
+        input_unregister_device(wm831x_on->dev);
+        kfree(wm831x_on);
+
+        return 0;
+}
+
+static struct platform_driver wm831x_on_driver = {
+        .probe          = wm831x_on_probe,
+        .remove         = __devexit_p(wm831x_on_remove),
+        .driver         = {
+                .name   = "wm831x-on",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init wm831x_on_init(void)
+{
+        return platform_driver_register(&wm831x_on_driver);
+}
+module_init(wm831x_on_init);
+
+static void __exit wm831x_on_exit(void)
+{
+        platform_driver_unregister(&wm831x_on_driver);
+}
+module_exit(wm831x_on_exit);
+
+MODULE_ALIAS("platform:wm831x-on");
+MODULE_DESCRIPTION("WM831x ON pin");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+