Input: add driver for Elan I2C/SMbus touchpad

This driver supports Elan I2C/SMbus touchpads found in some laptops and
also in many Chromebooks.

Signed-off-by: Duson Lin <dusonlin@emc.com.tw>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 611 insertions, 0 deletions

diff --git a/drivers/input/mouse/elan_i2c_i2c.c b/drivers/input/mouse/elan_i2c_i2c.c
new file mode 100644
index 00000000000..97d4937fc24
--- /dev/null
+++ b/drivers/input/mouse/elan_i2c_i2c.c
@@ -0,0 +1,611 @@
+/*
+ * Elan I2C/SMBus Touchpad driver - I2C interface
+ *
+ * Copyright (c) 2013 ELAN Microelectronics Corp.
+ *
+ * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
+ * Version: 1.5.5
+ *
+ * Based on cyapa driver:
+ * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
+ * copyright (c) 2011-2012 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Trademarks are the property of their respective owners.
+ */
+
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/unaligned.h>
+
+#include "elan_i2c.h"
+
+/* Elan i2c commands */
+#define ETP_I2C_RESET			0x0100
+#define ETP_I2C_WAKE_UP			0x0800
+#define ETP_I2C_SLEEP			0x0801
+#define ETP_I2C_DESC_CMD		0x0001
+#define ETP_I2C_REPORT_DESC_CMD		0x0002
+#define ETP_I2C_STAND_CMD		0x0005
+#define ETP_I2C_UNIQUEID_CMD		0x0101
+#define ETP_I2C_FW_VERSION_CMD		0x0102
+#define ETP_I2C_SM_VERSION_CMD		0x0103
+#define ETP_I2C_XY_TRACENUM_CMD		0x0105
+#define ETP_I2C_MAX_X_AXIS_CMD		0x0106
+#define ETP_I2C_MAX_Y_AXIS_CMD		0x0107
+#define ETP_I2C_RESOLUTION_CMD		0x0108
+#define ETP_I2C_IAP_VERSION_CMD		0x0110
+#define ETP_I2C_SET_CMD			0x0300
+#define ETP_I2C_POWER_CMD		0x0307
+#define ETP_I2C_FW_CHECKSUM_CMD		0x030F
+#define ETP_I2C_IAP_CTRL_CMD		0x0310
+#define ETP_I2C_IAP_CMD			0x0311
+#define ETP_I2C_IAP_RESET_CMD		0x0314
+#define ETP_I2C_IAP_CHECKSUM_CMD	0x0315
+#define ETP_I2C_CALIBRATE_CMD		0x0316
+#define ETP_I2C_MAX_BASELINE_CMD	0x0317
+#define ETP_I2C_MIN_BASELINE_CMD	0x0318
+
+#define ETP_I2C_REPORT_LEN		34
+#define ETP_I2C_DESC_LENGTH		30
+#define ETP_I2C_REPORT_DESC_LENGTH	158
+#define ETP_I2C_INF_LENGTH		2
+#define ETP_I2C_IAP_PASSWORD		0x1EA5
+#define ETP_I2C_IAP_RESET		0xF0F0
+#define ETP_I2C_MAIN_MODE_ON		(1 << 9)
+#define ETP_I2C_IAP_REG_L		0x01
+#define ETP_I2C_IAP_REG_H		0x06
+
+static int elan_i2c_read_block(struct i2c_client *client,
+			       u16 reg, u8 *val, u16 len)
+{
+	__le16 buf[] = {
+		cpu_to_le16(reg),
+	};
+	struct i2c_msg msgs[] = {
+		{
+			.addr = client->addr,
+			.flags = client->flags & I2C_M_TEN,
+			.len = sizeof(buf),
+			.buf = (u8 *)buf,
+		},
+		{
+			.addr = client->addr,
+			.flags = (client->flags & I2C_M_TEN) | I2C_M_RD,
+			.len = len,
+			.buf = val,
+		}
+	};
+	int ret;
+
+	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+	return ret == ARRAY_SIZE(msgs) ? 0 : (ret < 0 ? ret : -EIO);
+}
+
+static int elan_i2c_read_cmd(struct i2c_client *client, u16 reg, u8 *val)
+{
+	int retval;
+
+	retval = elan_i2c_read_block(client, reg, val, ETP_I2C_INF_LENGTH);
+	if (retval < 0) {
+		dev_err(&client->dev, "reading cmd (0x%04x) fail.\n", reg);
+		return retval;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_write_cmd(struct i2c_client *client, u16 reg, u16 cmd)
+{
+	__le16 buf[] = {
+		cpu_to_le16(reg),
+		cpu_to_le16(cmd),
+	};
+	struct i2c_msg msg = {
+		.addr = client->addr,
+		.flags = client->flags & I2C_M_TEN,
+		.len = sizeof(buf),
+		.buf = (u8 *)buf,
+	};
+	int ret;
+
+	ret = i2c_transfer(client->adapter, &msg, 1);
+	return ret == 1 ? 0 : (ret < 0 ? ret : -EIO);
+}
+
+static int elan_i2c_initialize(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	int error;
+	u8 val[256];
+
+	error = elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD, ETP_I2C_RESET);
+	if (error) {
+		dev_err(dev, "device reset failed: %d\n", error);
+		return error;
+	}
+
+	/* Wait for the device to reset */
+	msleep(100);
+
+	/* get reset acknowledgement 0000 */
+	error = i2c_master_recv(client, val, ETP_I2C_INF_LENGTH);
+	if (error < 0) {
+		dev_err(dev, "failed to read reset response: %d\n", error);
+		return error;
+	}
+
+	error = elan_i2c_read_block(client, ETP_I2C_DESC_CMD,
+				    val, ETP_I2C_DESC_LENGTH);
+	if (error) {
+		dev_err(dev, "cannot get device descriptor: %d\n", error);
+		return error;
+	}
+
+	error = elan_i2c_read_block(client, ETP_I2C_REPORT_DESC_CMD,
+				    val, ETP_I2C_REPORT_DESC_LENGTH);
+	if (error) {
+		dev_err(dev, "fetching report descriptor failed.: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_sleep_control(struct i2c_client *client, bool sleep)
+{
+	return elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD,
+				  sleep ? ETP_I2C_SLEEP : ETP_I2C_WAKE_UP);
+}
+
+static int elan_i2c_power_control(struct i2c_client *client, bool enable)
+{
+	u8 val[2];
+	u16 reg;
+	int error;
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_POWER_CMD, val);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to read current power state: %d\n",
+			error);
+		return error;
+	}
+
+	reg = le16_to_cpup((__le16 *)val);
+	if (enable)
+		reg &= ~ETP_DISABLE_POWER;
+	else
+		reg |= ETP_DISABLE_POWER;
+
+	error = elan_i2c_write_cmd(client, ETP_I2C_POWER_CMD, reg);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to write current power state: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_set_mode(struct i2c_client *client, u8 mode)
+{
+	return elan_i2c_write_cmd(client, ETP_I2C_SET_CMD, mode);
+}
+
+
+static int elan_i2c_calibrate(struct i2c_client *client)
+{
+	return elan_i2c_write_cmd(client, ETP_I2C_CALIBRATE_CMD, 1);
+}
+
+static int elan_i2c_calibrate_result(struct i2c_client *client, u8 *val)
+{
+	return elan_i2c_read_block(client, ETP_I2C_CALIBRATE_CMD, val, 1);
+}
+
+static int elan_i2c_get_baseline_data(struct i2c_client *client,
+				      bool max_baseline, u8 *value)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client,
+				  max_baseline ? ETP_I2C_MAX_BASELINE_CMD :
+						 ETP_I2C_MIN_BASELINE_CMD,
+				  val);
+	if (error)
+		return error;
+
+	*value = le16_to_cpup((__le16 *)val);
+
+	return 0;
+}
+
+static int elan_i2c_get_version(struct i2c_client *client,
+				bool iap, u8 *version)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client,
+				  iap ? ETP_I2C_IAP_VERSION_CMD :
+					ETP_I2C_FW_VERSION_CMD,
+				  val);
+	if (error) {
+		dev_err(&client->dev, "failed to get %s version: %d\n",
+			iap ? "IAP" : "FW", error);
+		return error;
+	}
+
+	*version = val[0];
+	return 0;
+}
+
+static int elan_i2c_get_sm_version(struct i2c_client *client, u8 *version)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_SM_VERSION_CMD, val);
+	if (error) {
+		dev_err(&client->dev, "failed to get SM version: %d\n", error);
+		return error;
+	}
+
+	*version = val[0];
+	return 0;
+}
+
+static int elan_i2c_get_product_id(struct i2c_client *client, u8 *id)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_UNIQUEID_CMD, val);
+	if (error) {
+		dev_err(&client->dev, "failed to get product ID: %d\n", error);
+		return error;
+	}
+
+	*id = val[0];
+	return 0;
+}
+
+static int elan_i2c_get_checksum(struct i2c_client *client,
+				 bool iap, u16 *csum)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client,
+				  iap ? ETP_I2C_IAP_CHECKSUM_CMD :
+					ETP_I2C_FW_CHECKSUM_CMD,
+				  val);
+	if (error) {
+		dev_err(&client->dev, "failed to get %s checksum: %d\n",
+			iap ? "IAP" : "FW", error);
+		return error;
+	}
+
+	*csum = le16_to_cpup((__le16 *)val);
+	return 0;
+}
+
+static int elan_i2c_get_max(struct i2c_client *client,
+			    unsigned int *max_x, unsigned int *max_y)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_MAX_X_AXIS_CMD, val);
+	if (error) {
+		dev_err(&client->dev, "failed to get X dimension: %d\n", error);
+		return error;
+	}
+
+	*max_x = le16_to_cpup((__le16 *)val) & 0x0fff;
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_MAX_Y_AXIS_CMD, val);
+	if (error) {
+		dev_err(&client->dev, "failed to get Y dimension: %d\n", error);
+		return error;
+	}
+
+	*max_y = le16_to_cpup((__le16 *)val) & 0x0fff;
+
+	return 0;
+}
+
+static int elan_i2c_get_resolution(struct i2c_client *client,
+				   u8 *hw_res_x, u8 *hw_res_y)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_RESOLUTION_CMD, val);
+	if (error) {
+		dev_err(&client->dev, "failed to get resolution: %d\n", error);
+		return error;
+	}
+
+	*hw_res_x = val[0];
+	*hw_res_y = val[1];
+
+	return 0;
+}
+
+static int elan_i2c_get_num_traces(struct i2c_client *client,
+				   unsigned int *x_traces,
+				   unsigned int *y_traces)
+{
+	int error;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_XY_TRACENUM_CMD, val);
+	if (error) {
+		dev_err(&client->dev, "failed to get trace info: %d\n", error);
+		return error;
+	}
+
+	*x_traces = val[0] - 1;
+	*y_traces = val[1] - 1;
+
+	return 0;
+}
+
+static int elan_i2c_iap_get_mode(struct i2c_client *client, enum tp_mode *mode)
+{
+	int error;
+	u16 constant;
+	u8 val[3];
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CTRL_CMD, val);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to read iap control register: %d\n",
+			error);
+		return error;
+	}
+
+	constant = le16_to_cpup((__le16 *)val);
+	dev_dbg(&client->dev, "iap control reg: 0x%04x.\n", constant);
+
+	*mode = (constant & ETP_I2C_MAIN_MODE_ON) ? MAIN_MODE : IAP_MODE;
+
+	return 0;
+}
+
+static int elan_i2c_iap_reset(struct i2c_client *client)
+{
+	int error;
+
+	error = elan_i2c_write_cmd(client, ETP_I2C_IAP_RESET_CMD,
+				   ETP_I2C_IAP_RESET);
+	if (error) {
+		dev_err(&client->dev, "cannot reset IC: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_set_flash_key(struct i2c_client *client)
+{
+	int error;
+
+	error = elan_i2c_write_cmd(client, ETP_I2C_IAP_CMD,
+				   ETP_I2C_IAP_PASSWORD);
+	if (error) {
+		dev_err(&client->dev, "cannot set flash key: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_prepare_fw_update(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	int error;
+	enum tp_mode mode;
+	u8 val[3];
+	u16 password;
+
+	/* Get FW in which mode	(IAP_MODE/MAIN_MODE)  */
+	error = elan_i2c_iap_get_mode(client, &mode);
+	if (error)
+		return error;
+
+	if (mode == IAP_MODE) {
+		/* Reset IC */
+		error = elan_i2c_iap_reset(client);
+		if (error)
+			return error;
+
+		msleep(30);
+	}
+
+	/* Set flash key*/
+	error = elan_i2c_set_flash_key(client);
+	if (error)
+		return error;
+
+	/* Wait for F/W IAP initialization */
+	msleep(mode == MAIN_MODE ? 100 : 30);
+
+	/* Check if we are in IAP mode or not */
+	error = elan_i2c_iap_get_mode(client, &mode);
+	if (error)
+		return error;
+
+	if (mode == MAIN_MODE) {
+		dev_err(dev, "wrong mode: %d\n", mode);
+		return -EIO;
+	}
+
+	/* Set flash key again */
+	error = elan_i2c_set_flash_key(client);
+	if (error)
+		return error;
+
+	/* Wait for F/W IAP initialization */
+	msleep(30);
+
+	/* read back to check we actually enabled successfully. */
+	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CMD, val);
+	if (error) {
+		dev_err(dev, "cannot read iap password: %d\n",
+			error);
+		return error;
+	}
+
+	password = le16_to_cpup((__le16 *)val);
+	if (password != ETP_I2C_IAP_PASSWORD) {
+		dev_err(dev, "wrong iap password: 0x%X\n", password);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_write_fw_block(struct i2c_client *client,
+				   const u8 *page, u16 checksum, int idx)
+{
+	struct device *dev = &client->dev;
+	u8 page_store[ETP_FW_PAGE_SIZE + 4];
+	u8 val[3];
+	u16 result;
+	int ret, error;
+
+	page_store[0] = ETP_I2C_IAP_REG_L;
+	page_store[1] = ETP_I2C_IAP_REG_H;
+	memcpy(&page_store[2], page, ETP_FW_PAGE_SIZE);
+	/* recode checksum at last two bytes */
+	put_unaligned_le16(checksum, &page_store[ETP_FW_PAGE_SIZE + 2]);
+
+	ret = i2c_master_send(client, page_store, sizeof(page_store));
+	if (ret != sizeof(page_store)) {
+		error = ret < 0 ? ret : -EIO;
+		dev_err(dev, "Failed to write page %d: %d\n", idx, error);
+		return error;
+	}
+
+	/* Wait for F/W to update one page ROM data. */
+	msleep(20);
+
+	error = elan_i2c_read_cmd(client, ETP_I2C_IAP_CTRL_CMD, val);
+	if (error) {
+		dev_err(dev, "Failed to read IAP write result: %d\n", error);
+		return error;
+	}
+
+	result = le16_to_cpup((__le16 *)val);
+	if (result & (ETP_FW_IAP_PAGE_ERR | ETP_FW_IAP_INTF_ERR)) {
+		dev_err(dev, "IAP reports failed write: %04hx\n",
+			result);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_finish_fw_update(struct i2c_client *client,
+				     struct completion *completion)
+{
+	struct device *dev = &client->dev;
+	long ret;
+	int error;
+	int len;
+	u8 buffer[ETP_I2C_INF_LENGTH];
+
+	reinit_completion(completion);
+	enable_irq(client->irq);
+
+	error = elan_i2c_write_cmd(client, ETP_I2C_STAND_CMD, ETP_I2C_RESET);
+	if (!error)
+		ret = wait_for_completion_interruptible_timeout(completion,
+							msecs_to_jiffies(300));
+	disable_irq(client->irq);
+
+	if (error) {
+		dev_err(dev, "device reset failed: %d\n", error);
+		return error;
+	} else if (ret == 0) {
+		dev_err(dev, "timeout waiting for device reset\n");
+		return -ETIMEDOUT;
+	} else if (ret < 0) {
+		error = ret;
+		dev_err(dev, "error waiting for device reset: %d\n", error);
+		return error;
+	}
+
+	len = i2c_master_recv(client, buffer, ETP_I2C_INF_LENGTH);
+	if (len != ETP_I2C_INF_LENGTH) {
+		error = len < 0 ? len : -EIO;
+		dev_err(dev, "failed to read INT signal: %d (%d)\n",
+			error, len);
+		return error;
+	}
+
+	return 0;
+}
+
+static int elan_i2c_get_report(struct i2c_client *client, u8 *report)
+{
+	int len;
+
+	len = i2c_master_recv(client, report, ETP_I2C_REPORT_LEN);
+	if (len < 0) {
+		dev_err(&client->dev, "failed to read report data: %d\n", len);
+		return len;
+	}
+
+	if (len != ETP_I2C_REPORT_LEN) {
+		dev_err(&client->dev,
+			"wrong report length (%d vs %d expected)\n",
+			len, ETP_I2C_REPORT_LEN);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+const struct elan_transport_ops elan_i2c_ops = {
+	.initialize		= elan_i2c_initialize,
+	.sleep_control		= elan_i2c_sleep_control,
+	.power_control		= elan_i2c_power_control,
+	.set_mode		= elan_i2c_set_mode,
+
+	.calibrate		= elan_i2c_calibrate,
+	.calibrate_result	= elan_i2c_calibrate_result,
+
+	.get_baseline_data	= elan_i2c_get_baseline_data,
+
+	.get_version		= elan_i2c_get_version,
+	.get_sm_version		= elan_i2c_get_sm_version,
+	.get_product_id		= elan_i2c_get_product_id,
+	.get_checksum		= elan_i2c_get_checksum,
+
+	.get_max		= elan_i2c_get_max,
+	.get_resolution		= elan_i2c_get_resolution,
+	.get_num_traces		= elan_i2c_get_num_traces,
+
+	.iap_get_mode		= elan_i2c_iap_get_mode,
+	.iap_reset		= elan_i2c_iap_reset,
+
+	.prepare_fw_update	= elan_i2c_prepare_fw_update,
+	.write_fw_block		= elan_i2c_write_fw_block,
+	.finish_fw_update	= elan_i2c_finish_fw_update,
+
+	.get_report		= elan_i2c_get_report,
+};