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Release 4.11 drivers/input/misc/ad714x.c

/*
 * 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); }

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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); }

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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; }

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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; }

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/* * 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; } }

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/* * 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]); } }

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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); }

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/* * 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); }

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/* * 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); }

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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); }

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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); }

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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; } }

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/* * 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); }

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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; } }

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/* * 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; }

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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; }

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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); }

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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); }

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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; } }

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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