// SPDX-License-Identifier: GPL-2.0-or-later /* * AD714X CapTouch Programmable Controller driver supporting AD7142/3/7/8/7A * * Copyright 2009-2011 Analog Devices Inc. */ #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 … #define AD714X_STG_CAL_EN_REG … #define AD714X_AMB_COMP_CTRL0_REG … #define AD714X_PARTID_REG … #define AD7142_PARTID … #define AD7143_PARTID … #define AD7147_PARTID … #define AD7148_PARTID … #define AD714X_STAGECFG_REG … #define AD714X_SYSCFG_REG … #define STG_LOW_INT_EN_REG … #define STG_HIGH_INT_EN_REG … #define STG_COM_INT_EN_REG … #define STG_LOW_INT_STA_REG … #define STG_HIGH_INT_STA_REG … #define STG_COM_INT_STA_REG … #define CDC_RESULT_S0 … #define CDC_RESULT_S1 … #define CDC_RESULT_S2 … #define CDC_RESULT_S3 … #define CDC_RESULT_S4 … #define CDC_RESULT_S5 … #define CDC_RESULT_S6 … #define CDC_RESULT_S7 … #define CDC_RESULT_S8 … #define CDC_RESULT_S9 … #define CDC_RESULT_S10 … #define CDC_RESULT_S11 … #define STAGE0_AMBIENT … #define STAGE1_AMBIENT … #define STAGE2_AMBIENT … #define STAGE3_AMBIENT … #define STAGE4_AMBIENT … #define STAGE5_AMBIENT … #define STAGE6_AMBIENT … #define STAGE7_AMBIENT … #define STAGE8_AMBIENT … #define STAGE9_AMBIENT … #define STAGE10_AMBIENT … #define STAGE11_AMBIENT … #define PER_STAGE_REG_NUM … #define STAGE_CFGREG_NUM … #define SYS_CFGREG_NUM … /* * driver information which will be used to maintain the software flow */ enum ad714x_device_state { … }; struct ad714x_slider_drv { … }; struct ad714x_wheel_drv { … }; struct ad714x_touchpad_drv { … }; struct ad714x_button_drv { … }; struct ad714x_driver_data { … }; /* * 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) { … } static void ad714x_use_thr_int(struct ad714x_chip *ad714x, int start_stage, int end_stage) { … } static int ad714x_cal_highest_stage(struct ad714x_chip *ad714x, int start_stage, int end_stage) { … } static int ad714x_cal_abs_pos(struct ad714x_chip *ad714x, int start_stage, int end_stage, int highest_stage, int max_coord) { … } /* * 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) { … } /* * 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) { … } static void ad714x_slider_cal_highest_stage(struct ad714x_chip *ad714x, int idx) { … } /* * 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) { … } /* * 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) { … } static void ad714x_slider_use_com_int(struct ad714x_chip *ad714x, int idx) { … } static void ad714x_slider_use_thr_int(struct ad714x_chip *ad714x, int idx) { … } static void ad714x_slider_state_machine(struct ad714x_chip *ad714x, int idx) { … } /* * 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) { … } static void ad714x_wheel_cal_sensor_val(struct ad714x_chip *ad714x, int idx) { … } /* * 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) { … } static void ad714x_wheel_cal_flt_pos(struct ad714x_chip *ad714x, int idx) { … } static void ad714x_wheel_use_com_int(struct ad714x_chip *ad714x, int idx) { … } static void ad714x_wheel_use_thr_int(struct ad714x_chip *ad714x, int idx) { … } static void ad714x_wheel_state_machine(struct ad714x_chip *ad714x, int idx) { … } static void touchpad_cal_sensor_val(struct ad714x_chip *ad714x, int idx) { … } static void touchpad_cal_highest_stage(struct ad714x_chip *ad714x, int idx) { … } /* * 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) { … } /* * 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) { … } static void touchpad_cal_flt_pos(struct ad714x_chip *ad714x, int idx) { … } /* * 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 … #define RIGHT_END_POINT_DETECTION_LEVEL … #define LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL … #define TOP_END_POINT_DETECTION_LEVEL … #define BOTTOM_END_POINT_DETECTION_LEVEL … #define TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL … static int touchpad_check_endpoint(struct ad714x_chip *ad714x, int idx) { … } static void touchpad_use_com_int(struct ad714x_chip *ad714x, int idx) { … } static void touchpad_use_thr_int(struct ad714x_chip *ad714x, int idx) { … } static void ad714x_touchpad_state_machine(struct ad714x_chip *ad714x, int idx) { … } static int ad714x_hw_detect(struct ad714x_chip *ad714x) { … } static void ad714x_hw_init(struct ad714x_chip *ad714x) { … } static irqreturn_t ad714x_interrupt_thread(int irq, void *data) { … } struct ad714x_chip *ad714x_probe(struct device *dev, u16 bus_type, int irq, ad714x_read_t read, ad714x_write_t write) { … } EXPORT_SYMBOL(…); static int ad714x_suspend(struct device *dev) { … } static int ad714x_resume(struct device *dev) { … } EXPORT_SIMPLE_DEV_PM_OPS(…); MODULE_DESCRIPTION(…) …; MODULE_AUTHOR(…) …; MODULE_LICENSE(…) …;
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