[PATCH v2 1/1] Input: add driver for Cypress APA I2C Trackpad

From: Benson Leung <bleung@chromium.org>
To: dmitry.torokhov@gmail.com, rydberg@euromail.se,
	linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: bleung@chromium.org, djkurtz@chromium.org, olofj@chromium.org,
	dudl@cypress.com
Subject: [PATCH v2 1/1] Input: add driver for Cypress APA I2C Trackpad
Date: Wed,  5 Dec 2012 16:48:19 -0800	[thread overview]
Message-ID: <1354754899-26701-2-git-send-email-bleung@chromium.org> (raw)
In-Reply-To: <1354754899-26701-1-git-send-email-bleung@chromium.org>

This patch introduces a driver for Cypress All Points Addressable
I2C Trackpad, including the ones in 2012 Samsung Chromebooks.

This device is compatible with MT protocol type B, providing identifiable
contacts.

Signed-off-by: Dudley Du <dudl@cypress.com>
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Benson Leung <bleung@chromium.org>
---
 Version history :
v2 : * Removed firmware update.
     * Removed sysfs properties related to firmware update and power mode.
     * Folded cyapa_detect into cyapa_probe.
     * Added support for middle and right mechanical buttons, if they exist.
     * Rearranged disable_irq/enable_irq in suspend and resume to prevent
         a power mode change from colliding with a read of tracking data.
     * Made cyapa_get_state more reliable.
     * Use IRQF_ONESHOT for threaded irq
     * Simplified cyapa_set_power_mode.
     * Removed extra kernel-doc style comments
     * Removed dev_dbg messages.
     * Cleaned up unused includes.
     * Cleaned up unused #defines
v1 : Initial
---
 drivers/input/mouse/Kconfig  |   12 +
 drivers/input/mouse/Makefile |    1 +
 drivers/input/mouse/cyapa.c  |  838 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 851 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/mouse/cyapa.c

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index cd6268c..23db30a 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -193,6 +193,18 @@ config MOUSE_BCM5974
 	  To compile this driver as a module, choose M here: the
 	  module will be called bcm5974.
 
+config MOUSE_CYAPA
+	tristate "Cypress APA I2C Trackpad support"
+	depends on I2C
+	help
+	  This driver adds support for Cypress All Points Addressable (APA)
+	  I2C Trackpads, including the ones used in 2012 Samsung Chromebooks.
+
+	  Say Y here if you have a Cypress APA I2C Trackpad.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called cyapa.
+
 config MOUSE_INPORT
 	tristate "InPort/MS/ATIXL busmouse"
 	depends on ISA
diff --git a/drivers/input/mouse/Makefile b/drivers/input/mouse/Makefile
index 46ba755..10b4773 100644
--- a/drivers/input/mouse/Makefile
+++ b/drivers/input/mouse/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_MOUSE_AMIGA)		+= amimouse.o
 obj-$(CONFIG_MOUSE_APPLETOUCH)		+= appletouch.o
 obj-$(CONFIG_MOUSE_ATARI)		+= atarimouse.o
 obj-$(CONFIG_MOUSE_BCM5974)		+= bcm5974.o
+obj-$(CONFIG_MOUSE_CYAPA)		+= cyapa.o
 obj-$(CONFIG_MOUSE_GPIO)		+= gpio_mouse.o
 obj-$(CONFIG_MOUSE_INPORT)		+= inport.o
 obj-$(CONFIG_MOUSE_LOGIBM)		+= logibm.o
diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
new file mode 100644
index 0000000..08cf1ce
--- /dev/null
+++ b/drivers/input/mouse/cyapa.c
@@ -0,0 +1,838 @@
+/*
+ * Cypress APA trackpad with I2C interface
+ *
+ * Author: Dudley Du <dudl@cypress.com>
+ * Further cleanup and restructuring by:
+ *   Daniel Kurtz <djkurtz@chromium.org>
+ *   Benson Leung <bleung@chromium.org>
+ *
+ * Copyright (C) 2011-2012 Cypress Semiconductor, Inc.
+ * Copyright (C) 2011-2012 Google, Inc.
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/* APA trackpad firmware generation */
+#define CYAPA_GEN3   0x03   /* support MT-protocol B with tracking ID. */
+
+#define CYAPA_NAME   "Cypress APA Trackpad (cyapa)"
+
+/* commands for read/write registers of Cypress trackpad */
+#define CYAPA_CMD_SOFT_RESET       0x00
+#define CYAPA_CMD_POWER_MODE       0x01
+#define CYAPA_CMD_DEV_STATUS       0x02
+#define CYAPA_CMD_GROUP_DATA       0x03
+#define CYAPA_CMD_GROUP_CMD        0x04
+#define CYAPA_CMD_GROUP_QUERY      0x05
+#define CYAPA_CMD_BL_STATUS        0x06
+#define CYAPA_CMD_BL_HEAD          0x07
+#define CYAPA_CMD_BL_CMD           0x08
+#define CYAPA_CMD_BL_DATA          0x09
+#define CYAPA_CMD_BL_ALL           0x0a
+#define CYAPA_CMD_BLK_PRODUCT_ID   0x0b
+#define CYAPA_CMD_BLK_HEAD         0x0c
+
+/* report data start reg offset address. */
+#define DATA_REG_START_OFFSET  0x0000
+
+#define BL_HEAD_OFFSET 0x00
+#define BL_DATA_OFFSET 0x10
+
+/*
+ * Operational Device Status Register
+ *
+ * bit 7: Valid interrupt source
+ * bit 6 - 4: Reserved
+ * bit 3 - 2: Power status
+ * bit 1 - 0: Device status
+ */
+#define REG_OP_STATUS     0x00
+#define OP_STATUS_SRC     0x80
+#define OP_STATUS_POWER   0x0c
+#define OP_STATUS_DEV     0x03
+#define OP_STATUS_MASK (OP_STATUS_SRC | OP_STATUS_POWER | OP_STATUS_DEV)
+
+/*
+ * Operational Finger Count/Button Flags Register
+ *
+ * bit 7 - 4: Number of touched finger
+ * bit 3: Valid data
+ * bit 2: Middle Physical Button
+ * bit 1: Right Physical Button
+ * bit 0: Left physical Button
+ */
+#define REG_OP_DATA1       0x01
+#define OP_DATA_VALID      0x08
+#define OP_DATA_MIDDLE_BTN 0x04
+#define OP_DATA_RIGHT_BTN  0x02
+#define OP_DATA_LEFT_BTN   0x01
+#define OP_DATA_BTN_MASK (OP_DATA_MIDDLE_BTN | OP_DATA_RIGHT_BTN | \
+			  OP_DATA_LEFT_BTN)
+
+/*
+ * Bootloader Status Register
+ *
+ * bit 7: Busy
+ * bit 6 - 5: Reserved
+ * bit 4: Bootloader running
+ * bit 3 - 1: Reserved
+ * bit 0: Checksum valid
+ */
+#define REG_BL_STATUS        0x01
+#define BL_STATUS_BUSY       0x80
+#define BL_STATUS_RUNNING    0x10
+#define BL_STATUS_DATA_VALID 0x08
+#define BL_STATUS_CSUM_VALID 0x01
+
+/*
+ * Bootloader Error Register
+ *
+ * bit 7: Invalid
+ * bit 6: Invalid security key
+ * bit 5: Bootloading
+ * bit 4: Command checksum
+ * bit 3: Flash protection error
+ * bit 2: Flash checksum error
+ * bit 1 - 0: Reserved
+ */
+#define REG_BL_ERROR         0x02
+#define BL_ERROR_INVALID     0x80
+#define BL_ERROR_INVALID_KEY 0x40
+#define BL_ERROR_BOOTLOADING 0x20
+#define BL_ERROR_CMD_CSUM    0x10
+#define BL_ERROR_FLASH_PROT  0x08
+#define BL_ERROR_FLASH_CSUM  0x04
+
+#define BL_STATUS_SIZE  3  /* length of bootloader status registers */
+#define BLK_HEAD_BYTES 32
+
+#define PRODUCT_ID_SIZE  16
+#define QUERY_DATA_SIZE  27
+#define REG_PROTOCOL_GEN_QUERY_OFFSET  20
+
+#define REG_OFFSET_DATA_BASE     0x0000
+#define REG_OFFSET_COMMAND_BASE  0x0028
+#define REG_OFFSET_QUERY_BASE    0x002a
+
+#define CAPABILITY_LEFT_BTN_MASK	(0x01 << 3)
+#define CAPABILITY_RIGHT_BTN_MASK	(0x01 << 4)
+#define CAPABILITY_MIDDLE_BTN_MASK	(0x01 << 5)
+#define CAPABILITY_BTN_MASK  (CAPABILITY_LEFT_BTN_MASK | \
+			      CAPABILITY_RIGHT_BTN_MASK | \
+			      CAPABILITY_MIDDLE_BTN_MASK)
+
+#define CYAPA_OFFSET_SOFT_RESET  REG_OFFSET_COMMAND_BASE
+
+#define REG_OFFSET_POWER_MODE (REG_OFFSET_COMMAND_BASE + 1)
+
+#define PWR_MODE_MASK   0xfc
+#define PWR_MODE_FULL_ACTIVE (0x3f << 2)
+#define PWR_MODE_IDLE        (0x05 << 2) /* default sleep time is 50 ms. */
+#define PWR_MODE_OFF         (0x00 << 2)
+
+#define PWR_STATUS_MASK      0x0c
+#define PWR_STATUS_ACTIVE    (0x03 << 2)
+#define PWR_STATUS_IDLE      (0x02 << 2)
+#define PWR_STATUS_OFF       (0x00 << 2)
+
+/*
+ * CYAPA trackpad device states.
+ * Used in register 0x00, bit1-0, DeviceStatus field.
+ * Other values indicate device is in an abnormal state and must be reset.
+ */
+#define CYAPA_DEV_NORMAL  0x03
+#define CYAPA_DEV_BUSY    0x01
+
+enum cyapa_state {
+	CYAPA_STATE_OP,
+	CYAPA_STATE_BL_IDLE,
+	CYAPA_STATE_BL_ACTIVE,
+	CYAPA_STATE_BL_BUSY,
+	CYAPA_STATE_NO_DEVICE,
+};
+
+
+struct cyapa_touch {
+	/*
+	 * high bits or x/y position value
+	 * bit 7 - 4: high 4 bits of x position value
+	 * bit 3 - 0: high 4 bits of y position value
+	 */
+	u8 xy_hi;
+	u8 x_lo;  /* low 8 bits of x position value. */
+	u8 y_lo;  /* low 8 bits of y position value. */
+	u8 pressure;
+	/* id range is 1 - 15.  It is incremented with every new touch. */
+	u8 id;
+} __packed;
+
+/* The touch.id is used as the MT slot id, thus max MT slot is 15 */
+#define CYAPA_MAX_MT_SLOTS  15
+
+struct cyapa_reg_data {
+	/*
+	 * bit 0 - 1: device status
+	 * bit 3 - 2: power mode
+	 * bit 6 - 4: reserved
+	 * bit 7: interrupt valid bit
+	 */
+	u8 device_status;
+	/*
+	 * bit 7 - 4: number of fingers currently touching pad
+	 * bit 3: valid data check bit
+	 * bit 2: middle mechanism button state if exists
+	 * bit 1: right mechanism button state if exists
+	 * bit 0: left mechanism button state if exists
+	 */
+	u8 finger_btn;
+	/* CYAPA reports up to 5 touches per packet. */
+	struct cyapa_touch touches[5];
+} __packed;
+
+/* The main device structure */
+struct cyapa {
+	enum cyapa_state state;
+
+	struct i2c_client *client;
+	struct input_dev *input;
+	char *phys;	/* device physical location */
+	int irq;
+	bool irq_wake;  /* irq wake is enabled */
+
+	/* read from query data region. */
+	char product_id[16];
+	u8 btn_capability;
+	u8 gen;
+	int max_abs_x;
+	int max_abs_y;
+	int physical_size_x;
+	int physical_size_y;
+};
+
+static const u8 bl_deactivate[] = { 0x00, 0xff, 0x3b, 0x00, 0x01, 0x02, 0x03,
+		0x04, 0x05, 0x06, 0x07 };
+static const u8 bl_exit[] = { 0x00, 0xff, 0xa5, 0x00, 0x01, 0x02, 0x03, 0x04,
+		0x05, 0x06, 0x07 };
+
+struct cyapa_cmd_len {
+	u8 cmd;
+	u8 len;
+};
+
+static const struct cyapa_cmd_len cyapa_i2c_cmds[] = {
+	{CYAPA_OFFSET_SOFT_RESET, 1},
+	{REG_OFFSET_COMMAND_BASE + 1, 1},
+	{REG_OFFSET_DATA_BASE, 1},
+	{REG_OFFSET_DATA_BASE, sizeof(struct cyapa_reg_data)},
+	{REG_OFFSET_COMMAND_BASE, 0},
+	{REG_OFFSET_QUERY_BASE, QUERY_DATA_SIZE},
+	{BL_HEAD_OFFSET, 3},
+	{BL_HEAD_OFFSET, 16},
+	{BL_HEAD_OFFSET, 16},
+	{BL_DATA_OFFSET, 16},
+	{BL_HEAD_OFFSET, 32},
+	{REG_OFFSET_QUERY_BASE, PRODUCT_ID_SIZE},
+	{REG_OFFSET_DATA_BASE, 32}
+};
+
+static ssize_t cyapa_i2c_reg_read_block(struct cyapa *cyapa, u8 reg, size_t len,
+					u8 *values)
+{
+	return i2c_smbus_read_i2c_block_data(cyapa->client, reg, len, values);
+}
+
+static ssize_t cyapa_i2c_reg_write_block(struct cyapa *cyapa, u8 reg,
+					 size_t len, const u8 *values)
+{
+	return i2c_smbus_write_i2c_block_data(cyapa->client, reg, len, values);
+}
+
+static s32 cyapa_read_byte(struct cyapa *cyapa, u8 cmd_idx)
+{
+	u8 cmd = cyapa_i2c_cmds[cmd_idx].cmd;
+
+	return i2c_smbus_read_byte_data(cyapa->client, cmd);
+}
+
+static s32 cyapa_write_byte(struct cyapa *cyapa, u8 cmd_idx, u8 value)
+{
+	u8 cmd = cyapa_i2c_cmds[cmd_idx].cmd;
+
+	return i2c_smbus_write_byte_data(cyapa->client, cmd, value);
+}
+
+static ssize_t cyapa_read_block(struct cyapa *cyapa, u8 cmd_idx, u8 *values)
+{
+	u8 cmd = cyapa_i2c_cmds[cmd_idx].cmd;
+	size_t len = cyapa_i2c_cmds[cmd_idx].len;
+
+	return cyapa_i2c_reg_read_block(cyapa, cmd, len, values);
+}
+
+/*
+ * Query device for its current operating state.
+ *
+ */
+static int cyapa_get_state(struct cyapa *cyapa)
+{
+	int ret;
+	u8 status[BL_STATUS_SIZE];
+
+	cyapa->state = CYAPA_STATE_NO_DEVICE;
+
+	/*
+	 * Get trackpad status by reading 3 registers starting from 0.
+	 * If the device is in the bootloader, this will be BL_HEAD.
+	 * If the device is in operation mode, this will be the DATA regs.
+	 *
+	 */
+	ret = cyapa_i2c_reg_read_block(cyapa, BL_HEAD_OFFSET, BL_STATUS_SIZE,
+				       status);
+	if (ret != BL_STATUS_SIZE)
+		goto error;
+
+	if ((status[REG_OP_STATUS] & OP_STATUS_SRC) == OP_STATUS_SRC) {
+		switch (status[REG_OP_STATUS] & OP_STATUS_DEV) {
+		case CYAPA_DEV_NORMAL:
+		case CYAPA_DEV_BUSY:
+			cyapa->state = CYAPA_STATE_OP;
+			break;
+		default:
+			ret = -EAGAIN;
+			goto error;
+		}
+	} else {
+		if (status[REG_BL_STATUS] & BL_STATUS_BUSY)
+			cyapa->state = CYAPA_STATE_BL_BUSY;
+		else if (status[REG_BL_ERROR] & BL_ERROR_BOOTLOADING)
+			cyapa->state = CYAPA_STATE_BL_ACTIVE;
+		else
+			cyapa->state = CYAPA_STATE_BL_IDLE;
+	}
+
+	return 0;
+error:
+	return (ret < 0) ? ret : -EAGAIN;
+}
+
+/*
+ * Poll device for its status in a loop, waiting up to timeout for a response.
+ *
+ * When the device switches state, it usually takes ~300 ms.
+ * However, when running a new firmware image, the device must calibrate its
+ * sensors, which can take as long as 2 seconds.
+ *
+ * Note: The timeout has granularity of the polling rate, which is 100 ms.
+ *
+ * Returns:
+ *   0 when the device eventually responds with a valid non-busy state.
+ *   -ETIMEDOUT if device never responds (too many -EAGAIN)
+ *   < 0    other errors
+ */
+static int cyapa_poll_state(struct cyapa *cyapa, unsigned int timeout)
+{
+	int ret;
+	int tries = timeout / 100;
+
+	ret = cyapa_get_state(cyapa);
+	while ((ret || cyapa->state >= CYAPA_STATE_BL_BUSY) && tries--) {
+		msleep(100);
+		ret = cyapa_get_state(cyapa);
+	}
+	return (ret == -EAGAIN || ret == -ETIMEDOUT) ? -ETIMEDOUT : ret;
+}
+
+static int cyapa_bl_deactivate(struct cyapa *cyapa)
+{
+	int ret;
+
+	ret = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_deactivate),
+					bl_deactivate);
+	if (ret < 0)
+		return ret;
+
+	/* wait for bootloader to switch to idle state; should take < 100ms */
+	msleep(100);
+	ret = cyapa_poll_state(cyapa, 500);
+	if (ret < 0)
+		return ret;
+	if (cyapa->state != CYAPA_STATE_BL_IDLE)
+		return -EAGAIN;
+	return 0;
+}
+
+/*
+ * Exit bootloader
+ *
+ * Send bl_exit command, then wait 50 - 100 ms to let device transition to
+ * operational mode.  If this is the first time the device's firmware is
+ * running, it can take up to 2 seconds to calibrate its sensors.  So, poll
+ * the device's new state for up to 2 seconds.
+ *
+ * Returns:
+ *   -EIO    failure while reading from device
+ *   -EAGAIN device is stuck in bootloader, b/c it has invalid firmware
+ *   0       device is supported and in operational mode
+ */
+static int cyapa_bl_exit(struct cyapa *cyapa)
+{
+	int ret;
+
+	ret = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_exit), bl_exit);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Wait for bootloader to exit, and operation mode to start.
+	 * Normally, this takes at least 50 ms.
+	 */
+	usleep_range(50000, 100000);
+	/*
+	 * In addition, when a device boots for the first time after being
+	 * updated to new firmware, it must first calibrate its sensors, which
+	 * can take up to an additional 2 seconds.
+	 */
+	ret = cyapa_poll_state(cyapa, 2000);
+	if (ret < 0)
+		return ret;
+	if (cyapa->state != CYAPA_STATE_OP)
+		return -EAGAIN;
+
+	return 0;
+}
+
+/*
+ * Set device power mode
+ *
+ */
+static int cyapa_set_power_mode(struct cyapa *cyapa, u8 power_mode)
+{
+	struct device *dev = &cyapa->client->dev;
+	int ret;
+	u8 power;
+
+	if (cyapa->state != CYAPA_STATE_OP)
+		return 0;
+
+	ret = cyapa_read_byte(cyapa, CYAPA_CMD_POWER_MODE);
+	if (ret < 0)
+		return ret;
+
+	power = ret & ~PWR_MODE_MASK;
+	power |= power_mode & PWR_MODE_MASK;
+	ret = cyapa_write_byte(cyapa, CYAPA_CMD_POWER_MODE, power);
+	if (ret < 0)
+		dev_err(dev, "failed to set power_mode 0x%02x err = %d\n",
+			power_mode, ret);
+	return ret;
+}
+
+static int cyapa_get_query_data(struct cyapa *cyapa)
+{
+	u8 query_data[QUERY_DATA_SIZE];
+	int ret;
+
+	if (cyapa->state != CYAPA_STATE_OP)
+		return -EBUSY;
+
+	ret = cyapa_read_block(cyapa, CYAPA_CMD_GROUP_QUERY, query_data);
+	if (ret < 0)
+		return ret;
+	if (ret != QUERY_DATA_SIZE)
+		return -EIO;
+
+	memcpy(&cyapa->product_id[0], &query_data[0], 5);
+	cyapa->product_id[5] = '-';
+	memcpy(&cyapa->product_id[6], &query_data[5], 6);
+	cyapa->product_id[12] = '-';
+	memcpy(&cyapa->product_id[13], &query_data[11], 2);
+	cyapa->product_id[15] = '\0';
+
+	cyapa->btn_capability = query_data[19] & CAPABILITY_BTN_MASK;
+
+	cyapa->gen = query_data[20] & 0x0f;
+
+	cyapa->max_abs_x = ((query_data[21] & 0xf0) << 4) | query_data[22];
+	cyapa->max_abs_y = ((query_data[21] & 0x0f) << 8) | query_data[23];
+
+	cyapa->physical_size_x =
+		((query_data[24] & 0xf0) << 4) | query_data[25];
+	cyapa->physical_size_y =
+		((query_data[24] & 0x0f) << 8) | query_data[26];
+
+	return 0;
+}
+
+/*
+ * Check if device is operational.
+ *
+ * An operational device is responding, has exited bootloader, and has
+ * firmware supported by this driver.
+ *
+ * Returns:
+ *   -EBUSY  no device or in bootloader
+ *   -EIO    failure while reading from device
+ *   -EAGAIN device is still in bootloader
+ *           if ->state = CYAPA_STATE_BL_IDLE, device has invalid firmware
+ *   -EINVAL device is in operational mode, but not supported by this driver
+ *   0       device is supported
+ */
+static int cyapa_check_is_operational(struct cyapa *cyapa)
+{
+	struct device *dev = &cyapa->client->dev;
+	static const char unique_str[] = "CYTRA";
+	int ret;
+
+	ret = cyapa_poll_state(cyapa, 2000);
+	if (ret < 0)
+		return ret;
+	switch (cyapa->state) {
+	case CYAPA_STATE_BL_ACTIVE:
+		ret = cyapa_bl_deactivate(cyapa);
+		if (ret)
+			return ret;
+
+	/* Fallthrough state */
+	case CYAPA_STATE_BL_IDLE:
+		ret = cyapa_bl_exit(cyapa);
+		if (ret)
+			return ret;
+
+	/* Fallthrough state */
+	case CYAPA_STATE_OP:
+		ret = cyapa_get_query_data(cyapa);
+		if (ret < 0)
+			return ret;
+
+		/* only support firmware protocol gen3 */
+		if (cyapa->gen != CYAPA_GEN3) {
+			dev_err(dev, "unsupported protocol version (%d)",
+				cyapa->gen);
+			return -EINVAL;
+		}
+
+		/* only support product ID starting with CYTRA */
+		if (memcmp(cyapa->product_id, unique_str,
+			   sizeof(unique_str) - 1) != 0) {
+			dev_err(dev, "unsupported product ID (%s)\n",
+				cyapa->product_id);
+			return -EINVAL;
+		}
+		return 0;
+
+	default:
+		return -EIO;
+	}
+	return 0;
+}
+
+static irqreturn_t cyapa_irq(int irq, void *dev_id)
+{
+	struct cyapa *cyapa = dev_id;
+	struct device *dev = &cyapa->client->dev;
+	struct input_dev *input = cyapa->input;
+	struct cyapa_reg_data data;
+	int i;
+	int ret;
+	int num_fingers;
+	unsigned int mask;
+
+	if (device_may_wakeup(dev))
+		pm_wakeup_event(dev, 0);
+
+	ret = cyapa_read_block(cyapa, CYAPA_CMD_GROUP_DATA, (u8 *)&data);
+	if (ret != sizeof(data))
+		goto irqhandled;
+
+	if ((data.device_status & OP_STATUS_SRC) != OP_STATUS_SRC ||
+	    (data.device_status & OP_STATUS_DEV) != CYAPA_DEV_NORMAL ||
+	    (data.finger_btn & OP_DATA_VALID) != OP_DATA_VALID) {
+		goto irqhandled;
+	}
+
+	mask = 0;
+	num_fingers = (data.finger_btn >> 4) & 0x0f;
+	for (i = 0; i < num_fingers; i++) {
+		const struct cyapa_touch *touch = &data.touches[i];
+		/* Note: touch->id range is 1 to 15; slots are 0 to 14. */
+		int slot = touch->id - 1;
+
+		mask |= (1 << slot);
+		input_mt_slot(input, slot);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+		input_report_abs(input, ABS_MT_POSITION_X,
+				 ((touch->xy_hi & 0xf0) << 4) | touch->x_lo);
+		input_report_abs(input, ABS_MT_POSITION_Y,
+				 ((touch->xy_hi & 0x0f) << 8) | touch->y_lo);
+		input_report_abs(input, ABS_MT_PRESSURE, touch->pressure);
+	}
+
+	/* Invalidate all unreported slots */
+	for (i = 0; i < CYAPA_MAX_MT_SLOTS; i++) {
+		if (mask & (1 << i))
+			continue;
+		input_mt_slot(input, i);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
+	}
+
+	input_mt_report_pointer_emulation(input, true);
+	if (cyapa->btn_capability & CAPABILITY_LEFT_BTN_MASK) {
+		input_report_key(input, BTN_LEFT,
+				 !!(data.finger_btn & OP_DATA_LEFT_BTN));
+	}
+	if (cyapa->btn_capability & CAPABILITY_MIDDLE_BTN_MASK) {
+		input_report_key(input, BTN_MIDDLE,
+				 !!(data.finger_btn & OP_DATA_MIDDLE_BTN));
+	}
+	if (cyapa->btn_capability & CAPABILITY_RIGHT_BTN_MASK) {
+		input_report_key(input, BTN_RIGHT,
+				 !!(data.finger_btn & OP_DATA_RIGHT_BTN));
+	}
+	input_sync(input);
+
+irqhandled:
+	return IRQ_HANDLED;
+}
+
+static int cyapa_create_input_dev(struct cyapa *cyapa)
+{
+	struct device *dev = &cyapa->client->dev;
+	int ret;
+	struct input_dev *input;
+
+	input = cyapa->input = input_allocate_device();
+	if (!input) {
+		dev_err(dev, "allocate memory for input device failed\n");
+		return -ENOMEM;
+	}
+
+	input->name = CYAPA_NAME;
+	input->phys = cyapa->phys;
+	input->id.bustype = BUS_I2C;
+	input->id.version = 1;
+	input->id.product = 0;  /* means any product in eventcomm. */
+	input->dev.parent = &cyapa->client->dev;
+
+	input_set_drvdata(input, cyapa);
+
+	__set_bit(EV_ABS, input->evbit);
+
+	/*
+	 * set and report not-MT axes to support synaptics X Driver.
+	 * When multi-fingers on trackpad, only the first finger touch
+	 * will be reported as X/Y axes values.
+	 */
+	input_set_abs_params(input, ABS_X, 0, cyapa->max_abs_x, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, cyapa->max_abs_y, 0, 0);
+	input_set_abs_params(input, ABS_PRESSURE, 0, 255, 0, 0);
+
+	/* finger position */
+	input_set_abs_params(input, ABS_MT_POSITION_X, 0, cyapa->max_abs_x, 0,
+			     0);
+	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, cyapa->max_abs_y, 0,
+			     0);
+	input_set_abs_params(input, ABS_MT_PRESSURE, 0, 255, 0, 0);
+	ret = input_mt_init_slots(input, CYAPA_MAX_MT_SLOTS);
+	if (ret < 0) {
+		dev_err(dev, "allocate memory for MT slots failed, %d\n", ret);
+		goto err_free_device;
+	}
+
+	if (cyapa->physical_size_x && cyapa->physical_size_y) {
+		input_abs_set_res(input, ABS_X,
+			cyapa->max_abs_x / cyapa->physical_size_x);
+		input_abs_set_res(input, ABS_Y,
+			cyapa->max_abs_y / cyapa->physical_size_y);
+		input_abs_set_res(input, ABS_MT_POSITION_X,
+			cyapa->max_abs_x / cyapa->physical_size_x);
+		input_abs_set_res(input, ABS_MT_POSITION_Y,
+			cyapa->max_abs_y / cyapa->physical_size_y);
+	}
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(BTN_TOUCH, input->keybit);
+	__set_bit(BTN_TOOL_FINGER, input->keybit);
+	__set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
+	__set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
+	__set_bit(BTN_TOOL_QUADTAP, input->keybit);
+	__set_bit(BTN_TOOL_QUINTTAP, input->keybit);
+
+	if (cyapa->btn_capability & CAPABILITY_LEFT_BTN_MASK)
+		__set_bit(BTN_LEFT, input->keybit);
+	if (cyapa->btn_capability & CAPABILITY_MIDDLE_BTN_MASK)
+		__set_bit(BTN_MIDDLE, input->keybit);
+	if (cyapa->btn_capability & CAPABILITY_RIGHT_BTN_MASK)
+		__set_bit(BTN_RIGHT, input->keybit);
+
+	__set_bit(INPUT_PROP_POINTER, input->propbit);
+	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+
+	/* Register the device in input subsystem */
+	ret = input_register_device(input);
+	if (ret) {
+		dev_err(dev, "input device register failed, %d\n", ret);
+		goto err_free_device;
+	}
+	return 0;
+
+err_free_device:
+	input_free_device(input);
+	cyapa->input = NULL;
+	return ret;
+}
+
+static int __devinit cyapa_probe(struct i2c_client *client,
+				 const struct i2c_device_id *dev_id)
+{
+	int ret;
+	struct cyapa *cyapa;
+	struct device *dev = &client->dev;
+
+	cyapa = kzalloc(sizeof(struct cyapa), GFP_KERNEL);
+	if (!cyapa) {
+		dev_err(dev, "allocate memory for cyapa failed\n");
+		return -ENOMEM;
+	}
+
+	cyapa->gen = CYAPA_GEN3;
+	cyapa->client = client;
+	i2c_set_clientdata(client, cyapa);
+	cyapa->phys = kasprintf(GFP_KERNEL, "i2c-%d-%04x/input0",
+				client->adapter->nr, client->addr);
+	if (!cyapa->phys) {
+		ret = -ENOMEM;
+		goto err_mem_free;
+	}
+
+	cyapa->state = CYAPA_STATE_NO_DEVICE;
+	ret = cyapa_check_is_operational(cyapa);
+	if (ret == -ETIMEDOUT) {
+		dev_err(dev, "no device detected, %d\n", ret);
+		goto err_mem_free;
+	} else if (ret) {
+		dev_err(dev, "device detected, but not operational, %d\n", ret);
+		goto err_mem_free;
+	}
+	ret = cyapa_create_input_dev(cyapa);
+	if (ret) {
+		dev_err(dev, "create input_dev instance failed, %d\n", ret);
+		goto err_mem_free;
+	}
+
+	ret = cyapa_set_power_mode(cyapa, PWR_MODE_FULL_ACTIVE);
+	if (ret) {
+		dev_err(dev, "set active power failed, %d\n", ret);
+		goto err_unregister_device;
+	}
+
+	cyapa->irq = client->irq;
+	ret = request_threaded_irq(cyapa->irq,
+				   NULL,
+				   cyapa_irq,
+				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				   "cyapa",
+				   cyapa);
+	if (ret) {
+		dev_err(dev, "IRQ request failed: %d\n, ", ret);
+		goto err_unregister_device;
+	}
+
+	return 0;
+
+err_unregister_device:
+	input_unregister_device(cyapa->input);
+err_mem_free:
+	kfree(cyapa->phys);
+	kfree(cyapa);
+
+	return ret;
+}
+
+static int __devexit cyapa_remove(struct i2c_client *client)
+{
+	struct cyapa *cyapa = i2c_get_clientdata(client);
+
+	free_irq(cyapa->irq, cyapa);
+	input_unregister_device(cyapa->input);
+	kfree(cyapa->phys);
+	kfree(cyapa);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cyapa_suspend(struct device *dev)
+{
+	int ret;
+	u8 power_mode;
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+
+	disable_irq(cyapa->irq);
+
+	/*
+	 * Set trackpad device to idle mode if wakeup is allowed,
+	 * otherwise turn off.
+	 */
+	power_mode = device_may_wakeup(dev) ? PWR_MODE_IDLE
+					    : PWR_MODE_OFF;
+	ret = cyapa_set_power_mode(cyapa, power_mode);
+	if (ret < 0)
+		dev_err(dev, "set power mode failed, %d\n", ret);
+
+	if (device_may_wakeup(dev))
+		cyapa->irq_wake = (enable_irq_wake(cyapa->irq) == 0);
+	return 0;
+}
+
+static int cyapa_resume(struct device *dev)
+{
+	int ret;
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev) && cyapa->irq_wake)
+		disable_irq_wake(cyapa->irq);
+
+	ret = cyapa_set_power_mode(cyapa, PWR_MODE_FULL_ACTIVE);
+	if (ret)
+		dev_warn(dev, "resume active power failed, %d\n", ret);
+
+	enable_irq(cyapa->irq);
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(cyapa_pm_ops, cyapa_suspend, cyapa_resume);
+
+static const struct i2c_device_id cyapa_id_table[] = {
+	{ "cyapa", 0 },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, cyapa_id_table);
+
+static struct i2c_driver cyapa_driver = {
+	.driver = {
+		.name = "cyapa",
+		.owner = THIS_MODULE,
+		.pm = &cyapa_pm_ops,
+	},
+
+	.probe = cyapa_probe,
+	.remove = __devexit_p(cyapa_remove),
+	.id_table = cyapa_id_table,
+};
+
+module_i2c_driver(cyapa_driver);
+
+MODULE_DESCRIPTION("Cypress APA I2C Trackpad Driver");
+MODULE_AUTHOR("Dudley Du <dudl@cypress.com>");
+MODULE_LICENSE("GPL");
-- 
1.7.7.3

