File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/input/misc/ad714x.c b/drivers/input/misc/ad714x.c
new file mode 100644
index 0000000..84b51dd
--- /dev/null
+++ b/drivers/input/misc/ad714x.c
@@ -0,0 +1,1210 @@
+/*
+ * AD714X CapTouch Programmable Controller driver supporting AD7142/3/7/8/7A
+ *
+ * Copyright 2009-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/device.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/input/ad714x.h>
+#include <linux/module.h>
+#include "ad714x.h"
+
+#define AD714X_PWR_CTRL 0x0
+#define AD714X_STG_CAL_EN_REG 0x1
+#define AD714X_AMB_COMP_CTRL0_REG 0x2
+#define AD714X_PARTID_REG 0x17
+#define AD7142_PARTID 0xE620
+#define AD7143_PARTID 0xE630
+#define AD7147_PARTID 0x1470
+#define AD7148_PARTID 0x1480
+#define AD714X_STAGECFG_REG 0x80
+#define AD714X_SYSCFG_REG 0x0
+
+#define STG_LOW_INT_EN_REG 0x5
+#define STG_HIGH_INT_EN_REG 0x6
+#define STG_COM_INT_EN_REG 0x7
+#define STG_LOW_INT_STA_REG 0x8
+#define STG_HIGH_INT_STA_REG 0x9
+#define STG_COM_INT_STA_REG 0xA
+
+#define CDC_RESULT_S0 0xB
+#define CDC_RESULT_S1 0xC
+#define CDC_RESULT_S2 0xD
+#define CDC_RESULT_S3 0xE
+#define CDC_RESULT_S4 0xF
+#define CDC_RESULT_S5 0x10
+#define CDC_RESULT_S6 0x11
+#define CDC_RESULT_S7 0x12
+#define CDC_RESULT_S8 0x13
+#define CDC_RESULT_S9 0x14
+#define CDC_RESULT_S10 0x15
+#define CDC_RESULT_S11 0x16
+
+#define STAGE0_AMBIENT 0xF1
+#define STAGE1_AMBIENT 0x115
+#define STAGE2_AMBIENT 0x139
+#define STAGE3_AMBIENT 0x15D
+#define STAGE4_AMBIENT 0x181
+#define STAGE5_AMBIENT 0x1A5
+#define STAGE6_AMBIENT 0x1C9
+#define STAGE7_AMBIENT 0x1ED
+#define STAGE8_AMBIENT 0x211
+#define STAGE9_AMBIENT 0x234
+#define STAGE10_AMBIENT 0x259
+#define STAGE11_AMBIENT 0x27D
+
+#define PER_STAGE_REG_NUM 36
+#define STAGE_CFGREG_NUM 8
+#define SYS_CFGREG_NUM 8
+
+/*
+ * driver information which will be used to maintain the software flow
+ */
+enum ad714x_device_state { IDLE, JITTER, ACTIVE, SPACE };
+
+struct ad714x_slider_drv {
+ int highest_stage;
+ int abs_pos;
+ int flt_pos;
+ enum ad714x_device_state state;
+ struct input_dev *input;
+};
+
+struct ad714x_wheel_drv {
+ int abs_pos;
+ int flt_pos;
+ int pre_highest_stage;
+ int highest_stage;
+ enum ad714x_device_state state;
+ struct input_dev *input;
+};
+
+struct ad714x_touchpad_drv {
+ int x_highest_stage;
+ int x_flt_pos;
+ int x_abs_pos;
+ int y_highest_stage;
+ int y_flt_pos;
+ int y_abs_pos;
+ int left_ep;
+ int left_ep_val;
+ int right_ep;
+ int right_ep_val;
+ int top_ep;
+ int top_ep_val;
+ int bottom_ep;
+ int bottom_ep_val;
+ enum ad714x_device_state state;
+ struct input_dev *input;
+};
+
+struct ad714x_button_drv {
+ enum ad714x_device_state state;
+ /*
+ * Unlike slider/wheel/touchpad, all buttons point to
+ * same input_dev instance
+ */
+ struct input_dev *input;
+};
+
+struct ad714x_driver_data {
+ struct ad714x_slider_drv *slider;
+ struct ad714x_wheel_drv *wheel;
+ struct ad714x_touchpad_drv *touchpad;
+ struct ad714x_button_drv *button;
+};
+
+/*
+ * information to integrate all things which will be private data
+ * of spi/i2c device
+ */
+
+static void ad714x_use_com_int(struct ad714x_chip *ad714x,
+ int start_stage, int end_stage)
+{
+ unsigned short data;
+ unsigned short mask;
+
+ mask = ((1 << (end_stage + 1)) - 1) - ((1 << start_stage) - 1);
+
+ ad714x->read(ad714x, STG_COM_INT_EN_REG, &data, 1);
+ data |= 1 << end_stage;
+ ad714x->write(ad714x, STG_COM_INT_EN_REG, data);
+
+ ad714x->read(ad714x, STG_HIGH_INT_EN_REG, &data, 1);
+ data &= ~mask;
+ ad714x->write(ad714x, STG_HIGH_INT_EN_REG, data);
+}
+
+static void ad714x_use_thr_int(struct ad714x_chip *ad714x,
+ int start_stage, int end_stage)
+{
+ unsigned short data;
+ unsigned short mask;
+
+ mask = ((1 << (end_stage + 1)) - 1) - ((1 << start_stage) - 1);
+
+ ad714x->read(ad714x, STG_COM_INT_EN_REG, &data, 1);
+ data &= ~(1 << end_stage);
+ ad714x->write(ad714x, STG_COM_INT_EN_REG, data);
+
+ ad714x->read(ad714x, STG_HIGH_INT_EN_REG, &data, 1);
+ data |= mask;
+ ad714x->write(ad714x, STG_HIGH_INT_EN_REG, data);
+}
+
+static int ad714x_cal_highest_stage(struct ad714x_chip *ad714x,
+ int start_stage, int end_stage)
+{
+ int max_res = 0;
+ int max_idx = 0;
+ int i;
+
+ for (i = start_stage; i <= end_stage; i++) {
+ if (ad714x->sensor_val[i] > max_res) {
+ max_res = ad714x->sensor_val[i];
+ max_idx = i;
+ }
+ }
+
+ return max_idx;
+}
+
+static int ad714x_cal_abs_pos(struct ad714x_chip *ad714x,
+ int start_stage, int end_stage,
+ int highest_stage, int max_coord)
+{
+ int a_param, b_param;
+
+ if (highest_stage == start_stage) {
+ a_param = ad714x->sensor_val[start_stage + 1];
+ b_param = ad714x->sensor_val[start_stage] +
+ ad714x->sensor_val[start_stage + 1];
+ } else if (highest_stage == end_stage) {
+ a_param = ad714x->sensor_val[end_stage] *
+ (end_stage - start_stage) +
+ ad714x->sensor_val[end_stage - 1] *
+ (end_stage - start_stage - 1);
+ b_param = ad714x->sensor_val[end_stage] +
+ ad714x->sensor_val[end_stage - 1];
+ } else {
+ a_param = ad714x->sensor_val[highest_stage] *
+ (highest_stage - start_stage) +
+ ad714x->sensor_val[highest_stage - 1] *
+ (highest_stage - start_stage - 1) +
+ ad714x->sensor_val[highest_stage + 1] *
+ (highest_stage - start_stage + 1);
+ b_param = ad714x->sensor_val[highest_stage] +
+ ad714x->sensor_val[highest_stage - 1] +
+ ad714x->sensor_val[highest_stage + 1];
+ }
+
+ return (max_coord / (end_stage - start_stage)) * a_param / b_param;
+}
+
+/*
+ * One button can connect to multi positive and negative of CDCs
+ * Multi-buttons can connect to same positive/negative of one CDC
+ */
+static void ad714x_button_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_button_plat *hw = &ad714x->hw->button[idx];
+ struct ad714x_button_drv *sw = &ad714x->sw->button[idx];
+
+ switch (sw->state) {
+ case IDLE:
+ if (((ad714x->h_state & hw->h_mask) == hw->h_mask) &&
+ ((ad714x->l_state & hw->l_mask) == hw->l_mask)) {
+ dev_dbg(ad714x->dev, "button %d touched\n", idx);
+ input_report_key(sw->input, hw->keycode, 1);
+ input_sync(sw->input);
+ sw->state = ACTIVE;
+ }
+ break;
+
+ case ACTIVE:
+ if (((ad714x->h_state & hw->h_mask) != hw->h_mask) ||
+ ((ad714x->l_state & hw->l_mask) != hw->l_mask)) {
+ dev_dbg(ad714x->dev, "button %d released\n", idx);
+ input_report_key(sw->input, hw->keycode, 0);
+ input_sync(sw->input);
+ sw->state = IDLE;
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * The response of a sensor is defined by the absolute number of codes
+ * between the current CDC value and the ambient value.
+ */
+static void ad714x_slider_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+ int i;
+
+ ad714x->read(ad714x, CDC_RESULT_S0 + hw->start_stage,
+ &ad714x->adc_reg[hw->start_stage],
+ hw->end_stage - hw->start_stage + 1);
+
+ for (i = hw->start_stage; i <= hw->end_stage; i++) {
+ ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
+ &ad714x->amb_reg[i], 1);
+
+ ad714x->sensor_val[i] =
+ abs(ad714x->adc_reg[i] - ad714x->amb_reg[i]);
+ }
+}
+
+static void ad714x_slider_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+ struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+
+ sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
+ hw->end_stage);
+
+ dev_dbg(ad714x->dev, "slider %d highest_stage:%d\n", idx,
+ sw->highest_stage);
+}
+
+/*
+ * The formulae are very straight forward. It uses the sensor with the
+ * highest response and the 2 adjacent ones.
+ * When Sensor 0 has the highest response, only sensor 0 and sensor 1
+ * are used in the calculations. Similarly when the last sensor has the
+ * highest response, only the last sensor and the second last sensors
+ * are used in the calculations.
+ *
+ * For i= idx_of_peak_Sensor-1 to i= idx_of_peak_Sensor+1
+ * v += Sensor response(i)*i
+ * w += Sensor response(i)
+ * POS=(Number_of_Positions_Wanted/(Number_of_Sensors_Used-1)) *(v/w)
+ */
+static void ad714x_slider_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+ struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+
+ sw->abs_pos = ad714x_cal_abs_pos(ad714x, hw->start_stage, hw->end_stage,
+ sw->highest_stage, hw->max_coord);
+
+ dev_dbg(ad714x->dev, "slider %d absolute position:%d\n", idx,
+ sw->abs_pos);
+}
+
+/*
+ * To minimise the Impact of the noise on the algorithm, ADI developed a
+ * routine that filters the CDC results after they have been read by the
+ * host processor.
+ * The filter used is an Infinite Input Response(IIR) filter implemented
+ * in firmware and attenuates the noise on the CDC results after they've
+ * been read by the host processor.
+ * Filtered_CDC_result = (Filtered_CDC_result * (10 - Coefficient) +
+ * Latest_CDC_result * Coefficient)/10
+ */
+static void ad714x_slider_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+
+ sw->flt_pos = (sw->flt_pos * (10 - 4) +
+ sw->abs_pos * 4)/10;
+
+ dev_dbg(ad714x->dev, "slider %d filter position:%d\n", idx,
+ sw->flt_pos);
+}
+
+static void ad714x_slider_use_com_int(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+
+ ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_slider_use_thr_int(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+
+ ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_slider_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+ struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+ unsigned short h_state, c_state;
+ unsigned short mask;
+
+ mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);
+
+ h_state = ad714x->h_state & mask;
+ c_state = ad714x->c_state & mask;
+
+ switch (sw->state) {
+ case IDLE:
+ if (h_state) {
+ sw->state = JITTER;
+ /* In End of Conversion interrupt mode, the AD714X
+ * continuously generates hardware interrupts.
+ */
+ ad714x_slider_use_com_int(ad714x, idx);
+ dev_dbg(ad714x->dev, "slider %d touched\n", idx);
+ }
+ break;
+
+ case JITTER:
+ if (c_state == mask) {
+ ad714x_slider_cal_sensor_val(ad714x, idx);
+ ad714x_slider_cal_highest_stage(ad714x, idx);
+ ad714x_slider_cal_abs_pos(ad714x, idx);
+ sw->flt_pos = sw->abs_pos;
+ sw->state = ACTIVE;
+ }
+ break;
+
+ case ACTIVE:
+ if (c_state == mask) {
+ if (h_state) {
+ ad714x_slider_cal_sensor_val(ad714x, idx);
+ ad714x_slider_cal_highest_stage(ad714x, idx);
+ ad714x_slider_cal_abs_pos(ad714x, idx);
+ ad714x_slider_cal_flt_pos(ad714x, idx);
+ input_report_abs(sw->input, ABS_X, sw->flt_pos);
+ input_report_key(sw->input, BTN_TOUCH, 1);
+ } else {
+ /* When the user lifts off the sensor, configure
+ * the AD714X back to threshold interrupt mode.
+ */
+ ad714x_slider_use_thr_int(ad714x, idx);
+ sw->state = IDLE;
+ input_report_key(sw->input, BTN_TOUCH, 0);
+ dev_dbg(ad714x->dev, "slider %d released\n",
+ idx);
+ }
+ input_sync(sw->input);
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * When the scroll wheel is activated, we compute the absolute position based
+ * on the sensor values. To calculate the position, we first determine the
+ * sensor that has the greatest response among the 8 sensors that constitutes
+ * the scrollwheel. Then we determined the 2 sensors on either sides of the
+ * sensor with the highest response and we apply weights to these sensors.
+ */
+static void ad714x_wheel_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+ struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+
+ sw->pre_highest_stage = sw->highest_stage;
+ sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
+ hw->end_stage);
+
+ dev_dbg(ad714x->dev, "wheel %d highest_stage:%d\n", idx,
+ sw->highest_stage);
+}
+
+static void ad714x_wheel_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+ int i;
+
+ ad714x->read(ad714x, CDC_RESULT_S0 + hw->start_stage,
+ &ad714x->adc_reg[hw->start_stage],
+ hw->end_stage - hw->start_stage + 1);
+
+ for (i = hw->start_stage; i <= hw->end_stage; i++) {
+ ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
+ &ad714x->amb_reg[i], 1);
+ if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
+ ad714x->sensor_val[i] =
+ ad714x->adc_reg[i] - ad714x->amb_reg[i];
+ else
+ ad714x->sensor_val[i] = 0;
+ }
+}
+
+/*
+ * When the scroll wheel is activated, we compute the absolute position based
+ * on the sensor values. To calculate the position, we first determine the
+ * sensor that has the greatest response among the sensors that constitutes
+ * the scrollwheel. Then we determined the sensors on either sides of the
+ * sensor with the highest response and we apply weights to these sensors. The
+ * result of this computation gives us the mean value.
+ */
+
+static void ad714x_wheel_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+ struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+ int stage_num = hw->end_stage - hw->start_stage + 1;
+ int first_before, highest, first_after;
+ int a_param, b_param;
+
+ first_before = (sw->highest_stage + stage_num - 1) % stage_num;
+ highest = sw->highest_stage;
+ first_after = (sw->highest_stage + stage_num + 1) % stage_num;
+
+ a_param = ad714x->sensor_val[highest] *
+ (highest - hw->start_stage) +
+ ad714x->sensor_val[first_before] *
+ (highest - hw->start_stage - 1) +
+ ad714x->sensor_val[first_after] *
+ (highest - hw->start_stage + 1);
+ b_param = ad714x->sensor_val[highest] +
+ ad714x->sensor_val[first_before] +
+ ad714x->sensor_val[first_after];
+
+ sw->abs_pos = ((hw->max_coord / (hw->end_stage - hw->start_stage)) *
+ a_param) / b_param;
+
+ if (sw->abs_pos > hw->max_coord)
+ sw->abs_pos = hw->max_coord;
+ else if (sw->abs_pos < 0)
+ sw->abs_pos = 0;
+}
+
+static void ad714x_wheel_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+ struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+ if (((sw->pre_highest_stage == hw->end_stage) &&
+ (sw->highest_stage == hw->start_stage)) ||
+ ((sw->pre_highest_stage == hw->start_stage) &&
+ (sw->highest_stage == hw->end_stage)))
+ sw->flt_pos = sw->abs_pos;
+ else
+ sw->flt_pos = ((sw->flt_pos * 30) + (sw->abs_pos * 71)) / 100;
+
+ if (sw->flt_pos > hw->max_coord)
+ sw->flt_pos = hw->max_coord;
+}
+
+static void ad714x_wheel_use_com_int(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+
+ ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_wheel_use_thr_int(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+
+ ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_wheel_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+ struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+ unsigned short h_state, c_state;
+ unsigned short mask;
+
+ mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);
+
+ h_state = ad714x->h_state & mask;
+ c_state = ad714x->c_state & mask;
+
+ switch (sw->state) {
+ case IDLE:
+ if (h_state) {
+ sw->state = JITTER;
+ /* In End of Conversion interrupt mode, the AD714X
+ * continuously generates hardware interrupts.
+ */
+ ad714x_wheel_use_com_int(ad714x, idx);
+ dev_dbg(ad714x->dev, "wheel %d touched\n", idx);
+ }
+ break;
+
+ case JITTER:
+ if (c_state == mask) {
+ ad714x_wheel_cal_sensor_val(ad714x, idx);
+ ad714x_wheel_cal_highest_stage(ad714x, idx);
+ ad714x_wheel_cal_abs_pos(ad714x, idx);
+ sw->flt_pos = sw->abs_pos;
+ sw->state = ACTIVE;
+ }
+ break;
+
+ case ACTIVE:
+ if (c_state == mask) {
+ if (h_state) {
+ ad714x_wheel_cal_sensor_val(ad714x, idx);
+ ad714x_wheel_cal_highest_stage(ad714x, idx);
+ ad714x_wheel_cal_abs_pos(ad714x, idx);
+ ad714x_wheel_cal_flt_pos(ad714x, idx);
+ input_report_abs(sw->input, ABS_WHEEL,
+ sw->flt_pos);
+ input_report_key(sw->input, BTN_TOUCH, 1);
+ } else {
+ /* When the user lifts off the sensor, configure
+ * the AD714X back to threshold interrupt mode.
+ */
+ ad714x_wheel_use_thr_int(ad714x, idx);
+ sw->state = IDLE;
+ input_report_key(sw->input, BTN_TOUCH, 0);
+
+ dev_dbg(ad714x->dev, "wheel %d released\n",
+ idx);
+ }
+ input_sync(sw->input);
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+static void touchpad_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+ int i;
+
+ ad714x->read(ad714x, CDC_RESULT_S0 + hw->x_start_stage,
+ &ad714x->adc_reg[hw->x_start_stage],
+ hw->x_end_stage - hw->x_start_stage + 1);
+
+ for (i = hw->x_start_stage; i <= hw->x_end_stage; i++) {
+ ad714x->read(ad714x, STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
+ &ad714x->amb_reg[i], 1);
+ if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
+ ad714x->sensor_val[i] =
+ ad714x->adc_reg[i] - ad714x->amb_reg[i];
+ else
+ ad714x->sensor_val[i] = 0;
+ }
+}
+
+static void touchpad_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+ struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+
+ sw->x_highest_stage = ad714x_cal_highest_stage(ad714x,
+ hw->x_start_stage, hw->x_end_stage);
+ sw->y_highest_stage = ad714x_cal_highest_stage(ad714x,
+ hw->y_start_stage, hw->y_end_stage);
+
+ dev_dbg(ad714x->dev,
+ "touchpad %d x_highest_stage:%d, y_highest_stage:%d\n",
+ idx, sw->x_highest_stage, sw->y_highest_stage);
+}
+
+/*
+ * If 2 fingers are touching the sensor then 2 peaks can be observed in the
+ * distribution.
+ * The arithmetic doesn't support to get absolute coordinates for multi-touch
+ * yet.
+ */
+static int touchpad_check_second_peak(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+ struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+ int i;
+
+ for (i = hw->x_start_stage; i < sw->x_highest_stage; i++) {
+ if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
+ > (ad714x->sensor_val[i + 1] / 10))
+ return 1;
+ }
+
+ for (i = sw->x_highest_stage; i < hw->x_end_stage; i++) {
+ if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
+ > (ad714x->sensor_val[i] / 10))
+ return 1;
+ }
+
+ for (i = hw->y_start_stage; i < sw->y_highest_stage; i++) {
+ if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
+ > (ad714x->sensor_val[i + 1] / 10))
+ return 1;
+ }
+
+ for (i = sw->y_highest_stage; i < hw->y_end_stage; i++) {
+ if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
+ > (ad714x->sensor_val[i] / 10))
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * If only one finger is used to activate the touch pad then only 1 peak will be
+ * registered in the distribution. This peak and the 2 adjacent sensors will be
+ * used in the calculation of the absolute position. This will prevent hand
+ * shadows to affect the absolute position calculation.
+ */
+static void touchpad_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+ struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+
+ sw->x_abs_pos = ad714x_cal_abs_pos(ad714x, hw->x_start_stage,
+ hw->x_end_stage, sw->x_highest_stage, hw->x_max_coord);
+ sw->y_abs_pos = ad714x_cal_abs_pos(ad714x, hw->y_start_stage,
+ hw->y_end_stage, sw->y_highest_stage, hw->y_max_coord);
+
+ dev_dbg(ad714x->dev, "touchpad %d absolute position:(%d, %d)\n", idx,
+ sw->x_abs_pos, sw->y_abs_pos);
+}
+
+static void touchpad_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+
+ sw->x_flt_pos = (sw->x_flt_pos * (10 - 4) +
+ sw->x_abs_pos * 4)/10;
+ sw->y_flt_pos = (sw->y_flt_pos * (10 - 4) +
+ sw->y_abs_pos * 4)/10;
+
+ dev_dbg(ad714x->dev, "touchpad %d filter position:(%d, %d)\n",
+ idx, sw->x_flt_pos, sw->y_flt_pos);
+}
+
+/*
+ * To prevent distortion from showing in the absolute position, it is
+ * necessary to detect the end points. When endpoints are detected, the
+ * driver stops updating the status variables with absolute positions.
+ * End points are detected on the 4 edges of the touchpad sensor. The
+ * method to detect them is the same for all 4.
+ * To detect the end points, the firmware computes the difference in
+ * percent between the sensor on the edge and the adjacent one. The
+ * difference is calculated in percent in order to make the end point
+ * detection independent of the pressure.
+ */
+
+#define LEFT_END_POINT_DETECTION_LEVEL 550
+#define RIGHT_END_POINT_DETECTION_LEVEL 750
+#define LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL 850
+#define TOP_END_POINT_DETECTION_LEVEL 550
+#define BOTTOM_END_POINT_DETECTION_LEVEL 950
+#define TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL 700
+static int touchpad_check_endpoint(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+ struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+ int percent_sensor_diff;
+
+ /* left endpoint detect */
+ percent_sensor_diff = (ad714x->sensor_val[hw->x_start_stage] -
+ ad714x->sensor_val[hw->x_start_stage + 1]) * 100 /
+ ad714x->sensor_val[hw->x_start_stage + 1];
+ if (!sw->left_ep) {
+ if (percent_sensor_diff >= LEFT_END_POINT_DETECTION_LEVEL) {
+ sw->left_ep = 1;
+ sw->left_ep_val =
+ ad714x->sensor_val[hw->x_start_stage + 1];
+ }
+ } else {
+ if ((percent_sensor_diff < LEFT_END_POINT_DETECTION_LEVEL) &&
+ (ad714x->sensor_val[hw->x_start_stage + 1] >
+ LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->left_ep_val))
+ sw->left_ep = 0;
+ }
+
+ /* right endpoint detect */
+ percent_sensor_diff = (ad714x->sensor_val[hw->x_end_stage] -
+ ad714x->sensor_val[hw->x_end_stage - 1]) * 100 /
+ ad714x->sensor_val[hw->x_end_stage - 1];
+ if (!sw->right_ep) {
+ if (percent_sensor_diff >= RIGHT_END_POINT_DETECTION_LEVEL) {
+ sw->right_ep = 1;
+ sw->right_ep_val =
+ ad714x->sensor_val[hw->x_end_stage - 1];
+ }
+ } else {
+ if ((percent_sensor_diff < RIGHT_END_POINT_DETECTION_LEVEL) &&
+ (ad714x->sensor_val[hw->x_end_stage - 1] >
+ LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->right_ep_val))
+ sw->right_ep = 0;
+ }
+
+ /* top endpoint detect */
+ percent_sensor_diff = (ad714x->sensor_val[hw->y_start_stage] -
+ ad714x->sensor_val[hw->y_start_stage + 1]) * 100 /
+ ad714x->sensor_val[hw->y_start_stage + 1];
+ if (!sw->top_ep) {
+ if (percent_sensor_diff >= TOP_END_POINT_DETECTION_LEVEL) {
+ sw->top_ep = 1;
+ sw->top_ep_val =
+ ad714x->sensor_val[hw->y_start_stage + 1];
+ }
+ } else {
+ if ((percent_sensor_diff < TOP_END_POINT_DETECTION_LEVEL) &&
+ (ad714x->sensor_val[hw->y_start_stage + 1] >
+ TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->top_ep_val))
+ sw->top_ep = 0;
+ }
+
+ /* bottom endpoint detect */
+ percent_sensor_diff = (ad714x->sensor_val[hw->y_end_stage] -
+ ad714x->sensor_val[hw->y_end_stage - 1]) * 100 /
+ ad714x->sensor_val[hw->y_end_stage - 1];
+ if (!sw->bottom_ep) {
+ if (percent_sensor_diff >= BOTTOM_END_POINT_DETECTION_LEVEL) {
+ sw->bottom_ep = 1;
+ sw->bottom_ep_val =
+ ad714x->sensor_val[hw->y_end_stage - 1];
+ }
+ } else {
+ if ((percent_sensor_diff < BOTTOM_END_POINT_DETECTION_LEVEL) &&
+ (ad714x->sensor_val[hw->y_end_stage - 1] >
+ TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->bottom_ep_val))
+ sw->bottom_ep = 0;
+ }
+
+ return sw->left_ep || sw->right_ep || sw->top_ep || sw->bottom_ep;
+}
+
+static void touchpad_use_com_int(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+
+ ad714x_use_com_int(ad714x, hw->x_start_stage, hw->x_end_stage);
+}
+
+static void touchpad_use_thr_int(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+
+ ad714x_use_thr_int(ad714x, hw->x_start_stage, hw->x_end_stage);
+ ad714x_use_thr_int(ad714x, hw->y_start_stage, hw->y_end_stage);
+}
+
+static void ad714x_touchpad_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+ struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+ struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+ unsigned short h_state, c_state;
+ unsigned short mask;
+
+ mask = (((1 << (hw->x_end_stage + 1)) - 1) -
+ ((1 << hw->x_start_stage) - 1)) +
+ (((1 << (hw->y_end_stage + 1)) - 1) -
+ ((1 << hw->y_start_stage) - 1));
+
+ h_state = ad714x->h_state & mask;
+ c_state = ad714x->c_state & mask;
+
+ switch (sw->state) {
+ case IDLE:
+ if (h_state) {
+ sw->state = JITTER;
+ /* In End of Conversion interrupt mode, the AD714X
+ * continuously generates hardware interrupts.
+ */
+ touchpad_use_com_int(ad714x, idx);
+ dev_dbg(ad714x->dev, "touchpad %d touched\n", idx);
+ }
+ break;
+
+ case JITTER:
+ if (c_state == mask) {
+ touchpad_cal_sensor_val(ad714x, idx);
+ touchpad_cal_highest_stage(ad714x, idx);
+ if ((!touchpad_check_second_peak(ad714x, idx)) &&
+ (!touchpad_check_endpoint(ad714x, idx))) {
+ dev_dbg(ad714x->dev,
+ "touchpad%d, 2 fingers or endpoint\n",
+ idx);
+ touchpad_cal_abs_pos(ad714x, idx);
+ sw->x_flt_pos = sw->x_abs_pos;
+ sw->y_flt_pos = sw->y_abs_pos;
+ sw->state = ACTIVE;
+ }
+ }
+ break;
+
+ case ACTIVE:
+ if (c_state == mask) {
+ if (h_state) {
+ touchpad_cal_sensor_val(ad714x, idx);
+ touchpad_cal_highest_stage(ad714x, idx);
+ if ((!touchpad_check_second_peak(ad714x, idx))
+ && (!touchpad_check_endpoint(ad714x, idx))) {
+ touchpad_cal_abs_pos(ad714x, idx);
+ touchpad_cal_flt_pos(ad714x, idx);
+ input_report_abs(sw->input, ABS_X,
+ sw->x_flt_pos);
+ input_report_abs(sw->input, ABS_Y,
+ sw->y_flt_pos);
+ input_report_key(sw->input, BTN_TOUCH,
+ 1);
+ }
+ } else {
+ /* When the user lifts off the sensor, configure
+ * the AD714X back to threshold interrupt mode.
+ */
+ touchpad_use_thr_int(ad714x, idx);
+ sw->state = IDLE;
+ input_report_key(sw->input, BTN_TOUCH, 0);
+ dev_dbg(ad714x->dev, "touchpad %d released\n",
+ idx);
+ }
+ input_sync(sw->input);
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+static int ad714x_hw_detect(struct ad714x_chip *ad714x)
+{
+ unsigned short data;
+
+ ad714x->read(ad714x, AD714X_PARTID_REG, &data, 1);
+ switch (data & 0xFFF0) {
+ case AD7142_PARTID:
+ ad714x->product = 0x7142;
+ ad714x->version = data & 0xF;
+ dev_info(ad714x->dev, "found AD7142 captouch, rev:%d\n",
+ ad714x->version);
+ return 0;
+
+ case AD7143_PARTID:
+ ad714x->product = 0x7143;
+ ad714x->version = data & 0xF;
+ dev_info(ad714x->dev, "found AD7143 captouch, rev:%d\n",
+ ad714x->version);
+ return 0;
+
+ case AD7147_PARTID:
+ ad714x->product = 0x7147;
+ ad714x->version = data & 0xF;
+ dev_info(ad714x->dev, "found AD7147(A) captouch, rev:%d\n",
+ ad714x->version);
+ return 0;
+
+ case AD7148_PARTID:
+ ad714x->product = 0x7148;
+ ad714x->version = data & 0xF;
+ dev_info(ad714x->dev, "found AD7148 captouch, rev:%d\n",
+ ad714x->version);
+ return 0;
+
+ default:
+ dev_err(ad714x->dev,
+ "fail to detect AD714X captouch, read ID is %04x\n",
+ data);
+ return -ENODEV;
+ }
+}
+
+static void ad714x_hw_init(struct ad714x_chip *ad714x)
+{
+ int i, j;
+ unsigned short reg_base;
+ unsigned short data;
+
+ /* configuration CDC and interrupts */
+
+ for (i = 0; i < STAGE_NUM; i++) {
+ reg_base = AD714X_STAGECFG_REG + i * STAGE_CFGREG_NUM;
+ for (j = 0; j < STAGE_CFGREG_NUM; j++)
+ ad714x->write(ad714x, reg_base + j,
+ ad714x->hw->stage_cfg_reg[i][j]);
+ }
+
+ for (i = 0; i < SYS_CFGREG_NUM; i++)
+ ad714x->write(ad714x, AD714X_SYSCFG_REG + i,
+ ad714x->hw->sys_cfg_reg[i]);
+ for (i = 0; i < SYS_CFGREG_NUM; i++)
+ ad714x->read(ad714x, AD714X_SYSCFG_REG + i, &data, 1);
+
+ ad714x->write(ad714x, AD714X_STG_CAL_EN_REG, 0xFFF);
+
+ /* clear all interrupts */
+ ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
+}
+
+static irqreturn_t ad714x_interrupt_thread(int irq, void *data)
+{
+ struct ad714x_chip *ad714x = data;
+ int i;
+
+ mutex_lock(&ad714x->mutex);
+
+ ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
+
+ for (i = 0; i < ad714x->hw->button_num; i++)
+ ad714x_button_state_machine(ad714x, i);
+ for (i = 0; i < ad714x->hw->slider_num; i++)
+ ad714x_slider_state_machine(ad714x, i);
+ for (i = 0; i < ad714x->hw->wheel_num; i++)
+ ad714x_wheel_state_machine(ad714x, i);
+ for (i = 0; i < ad714x->hw->touchpad_num; i++)
+ ad714x_touchpad_state_machine(ad714x, i);
+
+ mutex_unlock(&ad714x->mutex);
+
+ return IRQ_HANDLED;
+}
+
+struct ad714x_chip *ad714x_probe(struct device *dev, u16 bus_type, int irq,
+ ad714x_read_t read, ad714x_write_t write)
+{
+ int i;
+ int error;
+ struct input_dev *input;
+
+ struct ad714x_platform_data *plat_data = dev_get_platdata(dev);
+ struct ad714x_chip *ad714x;
+ void *drv_mem;
+ unsigned long irqflags;
+
+ struct ad714x_button_drv *bt_drv;
+ struct ad714x_slider_drv *sd_drv;
+ struct ad714x_wheel_drv *wl_drv;
+ struct ad714x_touchpad_drv *tp_drv;
+
+
+ if (irq <= 0) {
+ dev_err(dev, "IRQ not configured!\n");
+ error = -EINVAL;
+ return ERR_PTR(error);
+ }
+
+ if (dev_get_platdata(dev) == NULL) {
+ dev_err(dev, "platform data for ad714x doesn't exist\n");
+ error = -EINVAL;
+ return ERR_PTR(error);
+ }
+
+ ad714x = devm_kzalloc(dev, sizeof(*ad714x) + sizeof(*ad714x->sw) +
+ sizeof(*sd_drv) * plat_data->slider_num +
+ sizeof(*wl_drv) * plat_data->wheel_num +
+ sizeof(*tp_drv) * plat_data->touchpad_num +
+ sizeof(*bt_drv) * plat_data->button_num,
+ GFP_KERNEL);
+ if (!ad714x) {
+ error = -ENOMEM;
+ return ERR_PTR(error);
+ }
+ ad714x->hw = plat_data;
+
+ drv_mem = ad714x + 1;
+ ad714x->sw = drv_mem;
+ drv_mem += sizeof(*ad714x->sw);
+ ad714x->sw->slider = sd_drv = drv_mem;
+ drv_mem += sizeof(*sd_drv) * ad714x->hw->slider_num;
+ ad714x->sw->wheel = wl_drv = drv_mem;
+ drv_mem += sizeof(*wl_drv) * ad714x->hw->wheel_num;
+ ad714x->sw->touchpad = tp_drv = drv_mem;
+ drv_mem += sizeof(*tp_drv) * ad714x->hw->touchpad_num;
+ ad714x->sw->button = bt_drv = drv_mem;
+ drv_mem += sizeof(*bt_drv) * ad714x->hw->button_num;
+
+ ad714x->read = read;
+ ad714x->write = write;
+ ad714x->irq = irq;
+ ad714x->dev = dev;
+
+ error = ad714x_hw_detect(ad714x);
+ if (error)
+ return ERR_PTR(error);
+
+ /* initialize and request sw/hw resources */
+
+ ad714x_hw_init(ad714x);
+ mutex_init(&ad714x->mutex);
+
+ /* a slider uses one input_dev instance */
+ if (ad714x->hw->slider_num > 0) {
+ struct ad714x_slider_plat *sd_plat = ad714x->hw->slider;
+
+ for (i = 0; i < ad714x->hw->slider_num; i++) {
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return ERR_PTR(-ENOMEM);
+
+ __set_bit(EV_ABS, input->evbit);
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(ABS_X, input->absbit);
+ __set_bit(BTN_TOUCH, input->keybit);
+ input_set_abs_params(input,
+ ABS_X, 0, sd_plat->max_coord, 0, 0);
+
+ input->id.bustype = bus_type;
+ input->id.product = ad714x->product;
+ input->id.version = ad714x->version;
+ input->name = "ad714x_captouch_slider";
+ input->dev.parent = dev;
+
+ error = input_register_device(input);
+ if (error)
+ return ERR_PTR(error);
+
+ sd_drv[i].input = input;
+ }
+ }
+
+ /* a wheel uses one input_dev instance */
+ if (ad714x->hw->wheel_num > 0) {
+ struct ad714x_wheel_plat *wl_plat = ad714x->hw->wheel;
+
+ for (i = 0; i < ad714x->hw->wheel_num; i++) {
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return ERR_PTR(-ENOMEM);
+
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(EV_ABS, input->evbit);
+ __set_bit(ABS_WHEEL, input->absbit);
+ __set_bit(BTN_TOUCH, input->keybit);
+ input_set_abs_params(input,
+ ABS_WHEEL, 0, wl_plat->max_coord, 0, 0);
+
+ input->id.bustype = bus_type;
+ input->id.product = ad714x->product;
+ input->id.version = ad714x->version;
+ input->name = "ad714x_captouch_wheel";
+ input->dev.parent = dev;
+
+ error = input_register_device(input);
+ if (error)
+ return ERR_PTR(error);
+
+ wl_drv[i].input = input;
+ }
+ }
+
+ /* a touchpad uses one input_dev instance */
+ if (ad714x->hw->touchpad_num > 0) {
+ struct ad714x_touchpad_plat *tp_plat = ad714x->hw->touchpad;
+
+ for (i = 0; i < ad714x->hw->touchpad_num; i++) {
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return ERR_PTR(-ENOMEM);
+
+ __set_bit(EV_ABS, input->evbit);
+ __set_bit(EV_KEY, input->evbit);
+ __set_bit(ABS_X, input->absbit);
+ __set_bit(ABS_Y, input->absbit);
+ __set_bit(BTN_TOUCH, input->keybit);
+ input_set_abs_params(input,
+ ABS_X, 0, tp_plat->x_max_coord, 0, 0);
+ input_set_abs_params(input,
+ ABS_Y, 0, tp_plat->y_max_coord, 0, 0);
+
+ input->id.bustype = bus_type;
+ input->id.product = ad714x->product;
+ input->id.version = ad714x->version;
+ input->name = "ad714x_captouch_pad";
+ input->dev.parent = dev;
+
+ error = input_register_device(input);
+ if (error)
+ return ERR_PTR(error);
+
+ tp_drv[i].input = input;
+ }
+ }
+
+ /* all buttons use one input node */
+ if (ad714x->hw->button_num > 0) {
+ struct ad714x_button_plat *bt_plat = ad714x->hw->button;
+
+ input = devm_input_allocate_device(dev);
+ if (!input) {
+ error = -ENOMEM;
+ return ERR_PTR(error);
+ }
+
+ __set_bit(EV_KEY, input->evbit);
+ for (i = 0; i < ad714x->hw->button_num; i++) {
+ bt_drv[i].input = input;
+ __set_bit(bt_plat[i].keycode, input->keybit);
+ }
+
+ input->id.bustype = bus_type;
+ input->id.product = ad714x->product;
+ input->id.version = ad714x->version;
+ input->name = "ad714x_captouch_button";
+ input->dev.parent = dev;
+
+ error = input_register_device(input);
+ if (error)
+ return ERR_PTR(error);
+ }
+
+ irqflags = plat_data->irqflags ?: IRQF_TRIGGER_FALLING;
+ irqflags |= IRQF_ONESHOT;
+
+ error = devm_request_threaded_irq(dev, ad714x->irq, NULL,
+ ad714x_interrupt_thread,
+ irqflags, "ad714x_captouch", ad714x);
+ if (error) {
+ dev_err(dev, "can't allocate irq %d\n", ad714x->irq);
+ return ERR_PTR(error);
+ }
+
+ return ad714x;
+}
+EXPORT_SYMBOL(ad714x_probe);
+
+#ifdef CONFIG_PM
+int ad714x_disable(struct ad714x_chip *ad714x)
+{
+ unsigned short data;
+
+ dev_dbg(ad714x->dev, "%s enter\n", __func__);
+
+ mutex_lock(&ad714x->mutex);
+
+ data = ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL] | 0x3;
+ ad714x->write(ad714x, AD714X_PWR_CTRL, data);
+
+ mutex_unlock(&ad714x->mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL(ad714x_disable);
+
+int ad714x_enable(struct ad714x_chip *ad714x)
+{
+ dev_dbg(ad714x->dev, "%s enter\n", __func__);
+
+ mutex_lock(&ad714x->mutex);
+
+ /* resume to non-shutdown mode */
+
+ ad714x->write(ad714x, AD714X_PWR_CTRL,
+ ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL]);
+
+ /* make sure the interrupt output line is not low level after resume,
+ * otherwise we will get no chance to enter falling-edge irq again
+ */
+
+ ad714x->read(ad714x, STG_LOW_INT_STA_REG, &ad714x->l_state, 3);
+
+ mutex_unlock(&ad714x->mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL(ad714x_enable);
+#endif
+
+MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor Driver");
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_LICENSE("GPL");