Input: goldfish - virtual input event driver

This device is a direct pipe from "hardware" to the input event subsystem,
allowing us to avoid having to route "keypad" style events through an
AT keyboard driver (gross!).

As with the other submissions this driver is cross architecture.

Signed-off-by: Mike A. Chan <mikechan@google.com>
[Tided up to work on x86]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
[Ported to 3.4]
Signed-off-by: Tom Keel <thomas.keel@intel.com>
[Cleaned up for 3.7 and submission]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 194 insertions, 0 deletions

diff --git a/drivers/input/keyboard/goldfish_events.c b/drivers/input/keyboard/goldfish_events.c
new file mode 100644
index 000000000000..9f60a2ec88db
--- /dev/null
+++ b/drivers/input/keyboard/goldfish_events.c
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (C) 2012 Intel, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/types.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+enum {
+	REG_READ        = 0x00,
+	REG_SET_PAGE    = 0x00,
+	REG_LEN         = 0x04,
+	REG_DATA        = 0x08,
+
+	PAGE_NAME       = 0x00000,
+	PAGE_EVBITS     = 0x10000,
+	PAGE_ABSDATA    = 0x20000 | EV_ABS,
+};
+
+struct event_dev {
+	struct input_dev *input;
+	int irq;
+	void __iomem *addr;
+	char name[0];
+};
+
+static irqreturn_t events_interrupt(int irq, void *dev_id)
+{
+	struct event_dev *edev = dev_id;
+	unsigned type, code, value;
+
+	type = __raw_readl(edev->addr + REG_READ);
+	code = __raw_readl(edev->addr + REG_READ);
+	value = __raw_readl(edev->addr + REG_READ);
+
+	input_event(edev->input, type, code, value);
+	input_sync(edev->input);
+	return IRQ_HANDLED;
+}
+
+static void events_import_bits(struct event_dev *edev,
+			unsigned long bits[], unsigned type, size_t count)
+{
+	void __iomem *addr = edev->addr;
+	int i, j;
+	size_t size;
+	uint8_t val;
+
+	__raw_writel(PAGE_EVBITS | type, addr + REG_SET_PAGE);
+
+	size = __raw_readl(addr + REG_LEN) * 8;
+	if (size < count)
+		count = size;
+
+	addr += REG_DATA;
+	for (i = 0; i < count; i += 8) {
+		val = __raw_readb(addr++);
+		for (j = 0; j < 8; j++)
+			if (val & 1 << j)
+				set_bit(i + j, bits);
+	}
+}
+
+static void events_import_abs_params(struct event_dev *edev)
+{
+	struct input_dev *input_dev = edev->input;
+	void __iomem *addr = edev->addr;
+	u32 val[4];
+	int count;
+	int i, j;
+
+	__raw_writel(PAGE_ABSDATA, addr + REG_SET_PAGE);
+
+	count = __raw_readl(addr + REG_LEN) / sizeof(val);
+	if (count > ABS_MAX)
+		count = ABS_MAX;
+
+	for (i = 0; i < count; i++) {
+		if (!test_bit(i, input_dev->absbit))
+			continue;
+
+		for (j = 0; j < ARRAY_SIZE(val); j++) {
+			int offset = (i * ARRAY_SIZE(val) + j) * sizeof(u32);
+			val[j] = __raw_readl(edev->addr + REG_DATA + offset);
+		}
+
+		input_set_abs_params(input_dev, i,
+				     val[0], val[1], val[2], val[3]);
+	}
+}
+
+static int events_probe(struct platform_device *pdev)
+{
+	struct input_dev *input_dev;
+	struct event_dev *edev;
+	struct resource *res;
+	unsigned keymapnamelen;
+	void __iomem *addr;
+	int irq;
+	int i;
+	int error;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	addr = devm_ioremap(&pdev->dev, res->start, 4096);
+	if (!addr)
+		return -ENOMEM;
+
+	__raw_writel(PAGE_NAME, addr + REG_SET_PAGE);
+	keymapnamelen = __raw_readl(addr + REG_LEN);
+
+	edev = devm_kzalloc(&pdev->dev,
+			    sizeof(struct event_dev) + keymapnamelen + 1,
+			    GFP_KERNEL);
+	if (!edev)
+		return -ENOMEM;
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	edev->input = input_dev;
+	edev->addr = addr;
+	edev->irq = irq;
+
+	for (i = 0; i < keymapnamelen; i++)
+		edev->name[i] = __raw_readb(edev->addr + REG_DATA + i);
+
+	pr_debug("events_probe() keymap=%s\n", edev->name);
+
+	input_dev->name = edev->name;
+	input_dev->id.bustype = BUS_HOST;
+
+	events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);
+	events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);
+	events_import_bits(edev, input_dev->relbit, EV_REL, REL_MAX);
+	events_import_bits(edev, input_dev->absbit, EV_ABS, ABS_MAX);
+	events_import_bits(edev, input_dev->mscbit, EV_MSC, MSC_MAX);
+	events_import_bits(edev, input_dev->ledbit, EV_LED, LED_MAX);
+	events_import_bits(edev, input_dev->sndbit, EV_SND, SND_MAX);
+	events_import_bits(edev, input_dev->ffbit, EV_FF, FF_MAX);
+	events_import_bits(edev, input_dev->swbit, EV_SW, SW_MAX);
+
+	events_import_abs_params(edev);
+
+	error = devm_request_irq(&pdev->dev, edev->irq, events_interrupt, 0,
+				 "goldfish-events-keypad", edev);
+	if (error)
+		return error;
+
+	error = input_register_device(input_dev);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+static struct platform_driver events_driver = {
+	.probe	= events_probe,
+	.driver	= {
+		.owner	= THIS_MODULE,
+		.name	= "goldfish_events",
+	},
+};
+
+module_platform_driver(events_driver);
+
+MODULE_AUTHOR("Brian Swetland");
+MODULE_DESCRIPTION("Goldfish Event Device");
+MODULE_LICENSE("GPL");