diff options
author | Bryan Wu <cooloney@kernel.org> | 2010-03-21 23:23:24 -0700 |
---|---|---|
committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2010-04-13 23:27:16 -0700 |
commit | 31a6296333b94964e9a073649840bb34d4603369 (patch) | |
tree | 18c209d358420a889bc93e376d92e176cffb2326 /drivers/input/misc/ad714x.c | |
parent | a5b33e6a207d75120ad9dad0b5401b561991dcce (diff) |
Input: add Analog Devices AD714x captouch input driver
AD7142 and AD7147 are integrated capacitance-to-digital converters
(CDCs) with on-chip environmental calibration for use in systems
requiring a novel user input method. The AD7142 and AD7147 can interface
to external capacitance sensors implementing functions such as buttons,
scrollwheels, sliders, touchpads and so on.
The chips don't restrict the specific usage. Depending on the hardware
connection, one special target board can include one or several these
components. The platform_data for the device's "struct device" holds
these information. The data-struct defined in head file descript the
hardware feature of button/scrollwheel/slider/touchpad components on
target boards, which need be filled in the arch/mach-/.
As the result, the driver is independent of boards. It gets the
components layout from the platform_data, registers related devices,
fullfills the algorithms and state machines for these components and
report related input events to up level.
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Barry Song <21cnbao@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/misc/ad714x.c')
-rw-r--r-- | drivers/input/misc/ad714x.c | 1331 |
1 files changed, 1331 insertions, 0 deletions
diff --git a/drivers/input/misc/ad714x.c b/drivers/input/misc/ad714x.c new file mode 100644 index 000000000000..691b1d37331f --- /dev/null +++ b/drivers/input/misc/ad714x.c @@ -0,0 +1,1331 @@ +/* + * AD714X CapTouch Programmable Controller driver + * + * Copyright 2009 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#include <linux/device.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/input/ad714x.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 AD7147_PARTID 0x1470 +#define AD7142_PARTID 0xE620 +#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_NUM 12 +#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_mean_value; + int pre_highest_stage; + int pre_mean_value_no_offset; + int mean_value; + int mean_value_no_offset; + int pos_offset; + int pos_ratio; + 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 + */ +struct ad714x_chip { + unsigned short h_state; + unsigned short l_state; + unsigned short c_state; + unsigned short adc_reg[STAGE_NUM]; + unsigned short amb_reg[STAGE_NUM]; + unsigned short sensor_val[STAGE_NUM]; + + struct ad714x_platform_data *hw; + struct ad714x_driver_data *sw; + + int irq; + struct device *dev; + ad714x_read_t read; + ad714x_write_t write; + + struct mutex mutex; + + unsigned product; + unsigned version; +}; + +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); + + ad714x->read(ad714x->dev, STG_COM_INT_EN_REG, &data); + data |= 1 << start_stage; + ad714x->write(ad714x->dev, STG_COM_INT_EN_REG, data); + + ad714x->read(ad714x->dev, STG_HIGH_INT_EN_REG, &data); + data &= ~mask; + ad714x->write(ad714x->dev, 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); + + ad714x->read(ad714x->dev, STG_COM_INT_EN_REG, &data); + data &= ~(1 << start_stage); + ad714x->write(ad714x->dev, STG_COM_INT_EN_REG, data); + + ad714x->read(ad714x->dev, STG_HIGH_INT_EN_REG, &data); + data |= mask; + ad714x->write(ad714x->dev, 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; + + for (i = hw->start_stage; i <= hw->end_stage; i++) { + ad714x->read(ad714x->dev, CDC_RESULT_S0 + i, + &ad714x->adc_reg[i]); + ad714x->read(ad714x->dev, + STAGE0_AMBIENT + i * PER_STAGE_REG_NUM, + &ad714x->amb_reg[i]); + + 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; + + for (i = hw->start_stage; i <= hw->end_stage; i++) { + ad714x->read(ad714x->dev, CDC_RESULT_S0 + i, + &ad714x->adc_reg[i]); + ad714x->read(ad714x->dev, + STAGE0_AMBIENT + i * PER_STAGE_REG_NUM, + &ad714x->amb_reg[i]); + 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 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. The + * result of this computation gives us the mean value which defined by the + * following formula: + * For i= second_before_highest_stage to i= second_after_highest_stage + * v += Sensor response(i)*WEIGHT*(i+3) + * w += Sensor response(i) + * Mean_Value=v/w + * pos_on_scrollwheel = (Mean_Value - position_offset) / position_ratio + */ + +#define WEIGHT_FACTOR 30 +/* This constant prevents the "PositionOffset" from reaching a big value */ +#define OFFSET_POSITION_CLAMP 120 +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 second_before, first_before, highest, first_after, second_after; + int a_param, b_param; + + /* Calculate Mean value */ + + second_before = (sw->highest_stage + stage_num - 2) % stage_num; + first_before = (sw->highest_stage + stage_num - 1) % stage_num; + highest = sw->highest_stage; + first_after = (sw->highest_stage + stage_num + 1) % stage_num; + second_after = (sw->highest_stage + stage_num + 2) % stage_num; + + if (((sw->highest_stage - hw->start_stage) > 1) && + ((hw->end_stage - sw->highest_stage) > 1)) { + a_param = ad714x->sensor_val[second_before] * + (second_before - hw->start_stage + 3) + + ad714x->sensor_val[first_before] * + (second_before - hw->start_stage + 3) + + ad714x->sensor_val[highest] * + (second_before - hw->start_stage + 3) + + ad714x->sensor_val[first_after] * + (first_after - hw->start_stage + 3) + + ad714x->sensor_val[second_after] * + (second_after - hw->start_stage + 3); + } else { + a_param = ad714x->sensor_val[second_before] * + (second_before - hw->start_stage + 1) + + ad714x->sensor_val[first_before] * + (second_before - hw->start_stage + 2) + + ad714x->sensor_val[highest] * + (second_before - hw->start_stage + 3) + + ad714x->sensor_val[first_after] * + (first_after - hw->start_stage + 4) + + ad714x->sensor_val[second_after] * + (second_after - hw->start_stage + 5); + } + a_param *= WEIGHT_FACTOR; + + b_param = ad714x->sensor_val[second_before] + + ad714x->sensor_val[first_before] + + ad714x->sensor_val[highest] + + ad714x->sensor_val[first_after] + + ad714x->sensor_val[second_after]; + + sw->pre_mean_value = sw->mean_value; + sw->mean_value = a_param / b_param; + + /* Calculate the offset */ + + if ((sw->pre_highest_stage == hw->end_stage) && + (sw->highest_stage == hw->start_stage)) + sw->pos_offset = sw->mean_value; + else if ((sw->pre_highest_stage == hw->start_stage) && + (sw->highest_stage == hw->end_stage)) + sw->pos_offset = sw->pre_mean_value; + + if (sw->pos_offset > OFFSET_POSITION_CLAMP) + sw->pos_offset = OFFSET_POSITION_CLAMP; + + /* Calculate the mean value without the offset */ + + sw->pre_mean_value_no_offset = sw->mean_value_no_offset; + sw->mean_value_no_offset = sw->mean_value - sw->pos_offset; + if (sw->mean_value_no_offset < 0) + sw->mean_value_no_offset = 0; + + /* Calculate ratio to scale down to NUMBER_OF_WANTED_POSITIONS */ + + if ((sw->pre_highest_stage == hw->end_stage) && + (sw->highest_stage == hw->start_stage)) + sw->pos_ratio = (sw->pre_mean_value_no_offset * 100) / + hw->max_coord; + else if ((sw->pre_highest_stage == hw->start_stage) && + (sw->highest_stage == hw->end_stage)) + sw->pos_ratio = (sw->mean_value_no_offset * 100) / + hw->max_coord; + sw->abs_pos = (sw->mean_value_no_offset * 100) / sw->pos_ratio; + if (sw->abs_pos > hw->max_coord) + sw->abs_pos = hw->max_coord; +} + +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->abs_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; + + for (i = hw->x_start_stage; i <= hw->x_end_stage; i++) { + ad714x->read(ad714x->dev, CDC_RESULT_S0 + i, + &ad714x->adc_reg[i]); + ad714x->read(ad714x->dev, + STAGE0_AMBIENT + i * PER_STAGE_REG_NUM, + &ad714x->amb_reg[i]); + 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->dev, AD714X_PARTID_REG, &data); + switch (data & 0xFFF0) { + case AD7147_PARTID: + ad714x->product = 0x7147; + ad714x->version = data & 0xF; + dev_info(ad714x->dev, "found AD7147 captouch, rev:%d\n", + ad714x->version); + return 0; + + case AD7142_PARTID: + ad714x->product = 0x7142; + ad714x->version = data & 0xF; + dev_info(ad714x->dev, "found AD7142 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->dev, reg_base + j, + ad714x->hw->stage_cfg_reg[i][j]); + } + + for (i = 0; i < SYS_CFGREG_NUM; i++) + ad714x->write(ad714x->dev, AD714X_SYSCFG_REG + i, + ad714x->hw->sys_cfg_reg[i]); + for (i = 0; i < SYS_CFGREG_NUM; i++) + ad714x->read(ad714x->dev, AD714X_SYSCFG_REG + i, + &data); + + ad714x->write(ad714x->dev, AD714X_STG_CAL_EN_REG, 0xFFF); + + /* clear all interrupts */ + ad714x->read(ad714x->dev, STG_LOW_INT_STA_REG, &data); + ad714x->read(ad714x->dev, STG_HIGH_INT_STA_REG, &data); + ad714x->read(ad714x->dev, STG_COM_INT_STA_REG, &data); +} + +static irqreturn_t ad714x_interrupt_thread(int irq, void *data) +{ + struct ad714x_chip *ad714x = data; + int i; + + mutex_lock(&ad714x->mutex); + + ad714x->read(ad714x->dev, STG_LOW_INT_STA_REG, &ad714x->l_state); + ad714x->read(ad714x->dev, STG_HIGH_INT_STA_REG, &ad714x->h_state); + ad714x->read(ad714x->dev, STG_COM_INT_STA_REG, &ad714x->c_state); + + 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) |