driver/touchpad_elan: Basic elan touchpad driver

BRANCH=none
BUG=chrome-os-partner:59083
TEST=make BOARD=hammer -j && bash flash_hammer

Change-Id: I0ff4f48ff1399e054f745ac13ffacf81dffedeab
Reviewed-on: https://chromium-review.googlesource.com/407740
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

5 files changed, 274 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index 281afc92d0..0a6d109adc 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -74,6 +74,9 @@ driver-$(CONFIG_TEMP_SENSOR_G782)+=temp_sensor/g78x.o
 driver-$(CONFIG_TEMP_SENSOR_TMP006)+=temp_sensor/tmp006.o
 driver-$(CONFIG_TEMP_SENSOR_TMP432)+=temp_sensor/tmp432.o
 
+# Touchpads
+driver-$(CONFIG_TOUCHPAD_ELAN)+=touchpad_elan.o
+
 # Thermistors
 driver-$(CONFIG_THERMISTOR_NCP15WB)+=temp_sensor/thermistor_ncp15wb.o
 
diff --git a/driver/touchpad_elan.c b/driver/touchpad_elan.c
new file mode 100644
index 0000000000..e6b52fed1e
--- /dev/null
+++ b/driver/touchpad_elan.c
@@ -0,0 +1,245 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "common.h"
+#include "console.h"
+#include "touchpad_elan.h"
+#include "gpio.h"
+#include "i2c.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+
+/* Console output macros */
+#define CPUTS(outstr) cputs(CC_TOUCHPAD, outstr)
+#define CPRINTF(format, args...) cprintf(CC_TOUCHPAD, format, ## args)
+#define CPRINTS(format, args...) cprints(CC_TOUCHPAD, format, ## args)
+
+/******************************************************************************/
+/* How to talk to the controller */
+/******************************************************************************/
+
+#define ETP_I2C_RESET			0x0100
+#define ETP_I2C_WAKE_UP			0x0800
+#define ETP_I2C_SLEEP			0x0801
+#define ETP_I2C_STAND_CMD		0x0005
+#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_PRESSURE_CMD		0x010A
+#define ETP_I2C_SET_CMD			0x0300
+
+#define ETP_ENABLE_ABS		0x0001
+
+#define ETP_I2C_REPORT_LEN		34
+
+#define ETP_MAX_FINGERS		5
+#define ETP_FINGER_DATA_LEN	5
+
+#define ETP_PRESSURE_OFFSET	25
+#define ETP_FWIDTH_REDUCE	90
+
+#define ETP_REPORT_ID		0x5D
+#define ETP_REPORT_ID_OFFSET	2
+#define ETP_TOUCH_INFO_OFFSET	3
+#define ETP_FINGER_DATA_OFFSET	4
+#define ETP_HOVER_INFO_OFFSET	30
+#define ETP_MAX_REPORT_LEN	34
+
+struct {
+	/* Max X/Y position */
+	uint16_t max_x;
+	uint16_t max_y;
+	/* Scaling factor for finger width/height */
+	uint16_t width_x;
+	uint16_t width_y;
+	/* Pressure adjustment */
+	uint8_t pressure_adj;
+} elan_tp_params;
+
+static int elan_tp_read_cmd(uint16_t reg, uint16_t *val)
+{
+	uint8_t buf[2];
+	int rv;
+
+	buf[0] = reg;
+	buf[1] = reg >> 8;
+
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 1);
+	rv = i2c_xfer(CONFIG_TOUCHPAD_I2C_PORT, CONFIG_TOUCHPAD_I2C_ADDR,
+		      buf, sizeof(buf), (uint8_t *)val, sizeof(*val),
+		      I2C_XFER_SINGLE);
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 0);
+
+	return rv;
+}
+
+static int elan_tp_write_cmd(uint16_t reg, uint16_t val)
+{
+	uint8_t buf[4];
+	int rv;
+
+	buf[0] = reg;
+	buf[1] = reg >> 8;
+	buf[2] = val;
+	buf[3] = val >> 8;
+
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 1);
+	rv = i2c_xfer(CONFIG_TOUCHPAD_I2C_PORT, CONFIG_TOUCHPAD_I2C_ADDR,
+		      buf, sizeof(buf), NULL, 0, I2C_XFER_SINGLE);
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 0);
+
+	return rv;
+}
+
+static int elan_tp_read_report(void)
+{
+	int rv;
+	uint8_t tp_buf[ETP_I2C_REPORT_LEN];
+	int i;
+	uint8_t touch_info;
+	uint8_t hover_info;
+	uint8_t *finger = tp_buf+ETP_FINGER_DATA_OFFSET;
+
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 1);
+	rv = i2c_xfer(CONFIG_TOUCHPAD_I2C_PORT, CONFIG_TOUCHPAD_I2C_ADDR,
+		      NULL, 0, tp_buf, ETP_I2C_REPORT_LEN, I2C_XFER_SINGLE);
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 0);
+
+	if (rv) {
+		CPRINTS("read report error");
+		return rv;
+	}
+
+	CPRINTF("[%T ");
+#if 0
+	for (i = 0; i < ETP_I2C_REPORT_LEN; i++)
+		CPRINTF("%02x", tp_buf[i]);
+	CPRINTF(" || ");
+#endif
+
+	if (tp_buf[ETP_REPORT_ID_OFFSET] != ETP_REPORT_ID) {
+		CPRINTS("Invalid report id (%x)", tp_buf[ETP_REPORT_ID_OFFSET]);
+		return -1;
+	}
+
+	touch_info = tp_buf[ETP_TOUCH_INFO_OFFSET];
+	hover_info = tp_buf[ETP_HOVER_INFO_OFFSET];
+
+	if (touch_info & 0x01)
+		CPRINTF("click|");
+	if (hover_info & 0x40)
+		CPRINTF("hover|");
+
+	for (i = 0; i < ETP_MAX_FINGERS; i++) {
+		int valid = touch_info & (1 << (3+i));
+
+		if (valid) {
+			int x = ((finger[0] & 0xf0) << 4) | finger[1];
+			int y = ((finger[0] & 0x0f) << 8) | finger[2];
+			int width = (finger[3] & 0xf0) >> 4;
+			int height = finger[3] & 0x0f;
+			int pressure = finger[4];
+
+			y = elan_tp_params.max_y - y;
+			width = width * elan_tp_params.width_x;
+			height = height * elan_tp_params.width_y;
+			pressure = pressure + elan_tp_params.pressure_adj;
+
+			if (1)
+				CPRINTF("i=%d %d/%d %d/%d %d|", i, x, y,
+					width, height, pressure);
+			finger += ETP_FINGER_DATA_LEN;
+		}
+	}
+	CPRINTF("]\n");
+
+	return 0;
+}
+
+/* Initialize the controller ICs after reset */
+static int elan_tp_init(void)
+{
+	int rv;
+	uint8_t val[2];
+
+	CPRINTS("%s", __func__);
+
+	elan_tp_write_cmd(ETP_I2C_STAND_CMD, ETP_I2C_RESET);
+	msleep(100);
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 1);
+	rv = i2c_xfer(CONFIG_TOUCHPAD_I2C_PORT, CONFIG_TOUCHPAD_I2C_ADDR,
+		      NULL, 0, val, sizeof(val), I2C_XFER_SINGLE);
+	i2c_lock(CONFIG_TOUCHPAD_I2C_PORT, 0);
+
+	CPRINTS("reset rv %d buf=%04x", rv, *((uint16_t *)val));
+	if (rv)
+		goto out;
+
+	/* Read min/max */
+	rv = elan_tp_read_cmd(ETP_I2C_MAX_X_AXIS_CMD, &elan_tp_params.max_x);
+	if (rv)
+		goto out;
+	rv = elan_tp_read_cmd(ETP_I2C_MAX_Y_AXIS_CMD, &elan_tp_params.max_y);
+	if (rv)
+		goto out;
+
+	/* Read min/max */
+	rv = elan_tp_read_cmd(ETP_I2C_XY_TRACENUM_CMD, (uint16_t *)val);
+	if (rv)
+		goto out;
+	if (val[0] == 0 || val[1] == 0) {
+		CPRINTS("Invalid XY_TRACENUM");
+		goto out;
+	}
+
+	/* ETP_FWIDTH_REDUCE reduces the apparent width to avoid treating large
+	 * finger as palm. Multiply value by 2 as HID multitouch divides it.
+	 */
+	elan_tp_params.width_x =
+		2 * ((elan_tp_params.max_x / val[0]) - ETP_FWIDTH_REDUCE);
+	elan_tp_params.width_y =
+		2 * ((elan_tp_params.max_y / val[1]) - ETP_FWIDTH_REDUCE);
+
+	rv = elan_tp_read_cmd(ETP_I2C_PRESSURE_CMD, (uint16_t *)val);
+	if (rv)
+		goto out;
+	elan_tp_params.pressure_adj = (val[0] & 0x10) ? 0 : ETP_PRESSURE_OFFSET;
+
+	CPRINTS("max=%d/%d width=%d/%d adj=%d",
+		elan_tp_params.max_x, elan_tp_params.max_y,
+		elan_tp_params.width_x, elan_tp_params.width_y,
+		elan_tp_params.pressure_adj);
+
+	/* Switch to absolute mode */
+	rv = elan_tp_write_cmd(ETP_I2C_SET_CMD, ETP_ENABLE_ABS);
+	if (rv)
+		goto out;
+
+	/* Sleep control off */
+	rv = elan_tp_write_cmd(ETP_I2C_STAND_CMD, ETP_I2C_WAKE_UP);
+
+out:
+	CPRINTS("%s:%d", __func__, rv);
+	return rv;
+}
+
+void elan_tp_interrupt(enum gpio_signal signal)
+{
+	task_wake(TASK_ID_TOUCHPAD);
+}
+
+void elan_tp_task(void)
+{
+	elan_tp_init();
+
+	gpio_enable_interrupt(GPIO_TOUCHPAD_INT);
+
+	while (1) {
+		task_wait_event(-1);
+
+		elan_tp_read_report();
+	}
+}
diff --git a/driver/touchpad_elan.h b/driver/touchpad_elan.h
new file mode 100644
index 0000000000..4fb6d6e278
--- /dev/null
+++ b/driver/touchpad_elan.h
@@ -0,0 +1,13 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Elan touchpad driver for Chrome EC */
+
+#ifndef __CROS_EC_TOUCHPAD_ELAN_H
+#define __CROS_EC_TOUCHPAD_ELAN_H
+
+void elan_tp_interrupt(enum gpio_signal signal);
+
+#endif
diff --git a/include/config.h b/include/config.h
index 5cc38a6c14..3f8637e3f8 100644
--- a/include/config.h
+++ b/include/config.h
@@ -1904,6 +1904,16 @@
 #undef CONFIG_DPTF
 
 /*****************************************************************************/
+/* Touchpad config */
+
+/* Enable Elan driver */
+#undef CONFIG_TOUCHPAD_ELAN
+
+/* Set I2C port and address (8-bit) */
+#undef CONFIG_TOUCHPAD_I2C_PORT
+#undef CONFIG_TOUCHPAD_I2C_ADDR
+
+/*****************************************************************************/
 /* TPM-like configuration */
 
 /* Speak the TPM SPI Hardware Protocol on the SPI slave interface */
diff --git a/include/console_channel.inc b/include/console_channel.inc
index ba48a31563..7c3e8b3c99 100644
--- a/include/console_channel.inc
+++ b/include/console_channel.inc
@@ -66,6 +66,9 @@ CONSOLE_CHANNEL(CC_SWITCH,       "switch")
 #endif
 CONSOLE_CHANNEL(CC_SYSTEM,       "system")
 CONSOLE_CHANNEL(CC_TASK,         "task")
+#ifdef CONFIG_TOUCHPAD_ELAN
+CONSOLE_CHANNEL(CC_TOUCHPAD,     "touchpad")
+#endif
 #ifdef CONFIG_DPTF
 CONSOLE_CHANNEL(CC_DPTF,         "dptf")
 #endif