530 lines
13 KiB
C
530 lines
13 KiB
C
/*
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* TI Touch Screen driver
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*
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* Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/clk.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/delay.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/mfd/ti_am335x_tscadc.h>
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#define ADCFSM_STEPID 0x10
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#define SEQ_SETTLE 275
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#define MAX_12BIT ((1 << 12) - 1)
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static const int config_pins[] = {
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STEPCONFIG_XPP,
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STEPCONFIG_XNN,
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STEPCONFIG_YPP,
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STEPCONFIG_YNN,
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};
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struct titsc {
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struct input_dev *input;
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struct ti_tscadc_dev *mfd_tscadc;
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unsigned int irq;
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unsigned int wires;
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unsigned int x_plate_resistance;
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bool pen_down;
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int coordinate_readouts;
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u32 config_inp[4];
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u32 bit_xp, bit_xn, bit_yp, bit_yn;
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u32 inp_xp, inp_xn, inp_yp, inp_yn;
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u32 step_mask;
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};
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static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
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{
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return readl(ts->mfd_tscadc->tscadc_base + reg);
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}
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static void titsc_writel(struct titsc *tsc, unsigned int reg,
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unsigned int val)
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{
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writel(val, tsc->mfd_tscadc->tscadc_base + reg);
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}
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static int titsc_config_wires(struct titsc *ts_dev)
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{
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u32 analog_line[4];
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u32 wire_order[4];
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int i, bit_cfg;
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for (i = 0; i < 4; i++) {
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/*
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* Get the order in which TSC wires are attached
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* w.r.t. each of the analog input lines on the EVM.
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*/
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analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
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wire_order[i] = ts_dev->config_inp[i] & 0x0F;
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if (WARN_ON(analog_line[i] > 7))
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return -EINVAL;
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if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
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return -EINVAL;
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}
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for (i = 0; i < 4; i++) {
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int an_line;
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int wi_order;
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an_line = analog_line[i];
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wi_order = wire_order[i];
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bit_cfg = config_pins[wi_order];
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if (bit_cfg == 0)
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return -EINVAL;
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switch (wi_order) {
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case 0:
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ts_dev->bit_xp = bit_cfg;
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ts_dev->inp_xp = an_line;
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break;
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case 1:
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ts_dev->bit_xn = bit_cfg;
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ts_dev->inp_xn = an_line;
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break;
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case 2:
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ts_dev->bit_yp = bit_cfg;
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ts_dev->inp_yp = an_line;
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break;
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case 3:
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ts_dev->bit_yn = bit_cfg;
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ts_dev->inp_yn = an_line;
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break;
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}
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}
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return 0;
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}
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static void titsc_step_config(struct titsc *ts_dev)
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{
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unsigned int config;
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int i;
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int end_step;
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u32 stepenable;
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config = STEPCONFIG_MODE_HWSYNC |
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STEPCONFIG_AVG_16 | ts_dev->bit_xp;
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switch (ts_dev->wires) {
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case 4:
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config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
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break;
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case 5:
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config |= ts_dev->bit_yn |
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STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
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ts_dev->bit_yp;
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break;
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case 8:
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config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
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break;
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}
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/* 1 … coordinate_readouts is for X */
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end_step = ts_dev->coordinate_readouts;
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for (i = 0; i < end_step; i++) {
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titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
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titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
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}
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config = 0;
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config = STEPCONFIG_MODE_HWSYNC |
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STEPCONFIG_AVG_16 | ts_dev->bit_yn |
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STEPCONFIG_INM_ADCREFM;
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switch (ts_dev->wires) {
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case 4:
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config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
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break;
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case 5:
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config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
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ts_dev->bit_xn | ts_dev->bit_yp;
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break;
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case 8:
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config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
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break;
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}
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/* coordinate_readouts … coordinate_readouts * 2 is for Y */
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end_step = ts_dev->coordinate_readouts * 2;
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for (i = ts_dev->coordinate_readouts; i < end_step; i++) {
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titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
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titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
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}
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/* Charge step configuration */
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config = ts_dev->bit_xp | ts_dev->bit_yn |
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STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
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STEPCHARGE_INM_AN1 | STEPCHARGE_INP(ts_dev->inp_yp);
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titsc_writel(ts_dev, REG_CHARGECONFIG, config);
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titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
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/* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */
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config = STEPCONFIG_MODE_HWSYNC |
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STEPCONFIG_AVG_16 | ts_dev->bit_yp |
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ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
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STEPCONFIG_INP(ts_dev->inp_xp);
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titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
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titsc_writel(ts_dev, REG_STEPDELAY(end_step),
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STEPCONFIG_OPENDLY);
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end_step++;
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config |= STEPCONFIG_INP(ts_dev->inp_yn);
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titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
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titsc_writel(ts_dev, REG_STEPDELAY(end_step),
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STEPCONFIG_OPENDLY);
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/* The steps1 … end and bit 0 for TS_Charge */
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stepenable = (1 << (end_step + 2)) - 1;
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ts_dev->step_mask = stepenable;
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am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
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}
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static void titsc_read_coordinates(struct titsc *ts_dev,
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u32 *x, u32 *y, u32 *z1, u32 *z2)
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{
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unsigned int fifocount = titsc_readl(ts_dev, REG_FIFO0CNT);
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unsigned int prev_val_x = ~0, prev_val_y = ~0;
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unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
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unsigned int read, diff;
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unsigned int i, channel;
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unsigned int creads = ts_dev->coordinate_readouts;
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*z1 = *z2 = 0;
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if (fifocount % (creads * 2 + 2))
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fifocount -= fifocount % (creads * 2 + 2);
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/*
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* Delta filter is used to remove large variations in sampled
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* values from ADC. The filter tries to predict where the next
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* coordinate could be. This is done by taking a previous
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* coordinate and subtracting it form current one. Further the
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* algorithm compares the difference with that of a present value,
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* if true the value is reported to the sub system.
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*/
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for (i = 0; i < fifocount; i++) {
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read = titsc_readl(ts_dev, REG_FIFO0);
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channel = (read & 0xf0000) >> 16;
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read &= 0xfff;
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if (channel < creads) {
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diff = abs(read - prev_val_x);
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if (diff < prev_diff_x) {
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prev_diff_x = diff;
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*x = read;
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}
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prev_val_x = read;
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} else if (channel < creads * 2) {
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diff = abs(read - prev_val_y);
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if (diff < prev_diff_y) {
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prev_diff_y = diff;
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*y = read;
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}
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prev_val_y = read;
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} else if (channel < creads * 2 + 1) {
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*z1 = read;
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} else if (channel < creads * 2 + 2) {
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*z2 = read;
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}
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}
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}
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static irqreturn_t titsc_irq(int irq, void *dev)
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{
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struct titsc *ts_dev = dev;
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struct input_dev *input_dev = ts_dev->input;
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unsigned int status, irqclr = 0;
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unsigned int x = 0, y = 0;
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unsigned int z1, z2, z;
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unsigned int fsm;
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status = titsc_readl(ts_dev, REG_IRQSTATUS);
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/*
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* ADC and touchscreen share the IRQ line.
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* FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
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*/
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if (status & IRQENB_FIFO0THRES) {
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titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
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if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
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/*
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* Calculate pressure using formula
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* Resistance(touch) = x plate resistance *
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* x postion/4096 * ((z2 / z1) - 1)
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*/
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z = z1 - z2;
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z *= x;
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z *= ts_dev->x_plate_resistance;
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z /= z2;
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z = (z + 2047) >> 12;
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if (z <= MAX_12BIT) {
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input_report_abs(input_dev, ABS_X, x);
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input_report_abs(input_dev, ABS_Y, y);
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input_report_abs(input_dev, ABS_PRESSURE, z);
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input_report_key(input_dev, BTN_TOUCH, 1);
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input_sync(input_dev);
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}
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}
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irqclr |= IRQENB_FIFO0THRES;
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}
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/*
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* Time for sequencer to settle, to read
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* correct state of the sequencer.
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*/
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udelay(SEQ_SETTLE);
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status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
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if (status & IRQENB_PENUP) {
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/* Pen up event */
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fsm = titsc_readl(ts_dev, REG_ADCFSM);
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if (fsm == ADCFSM_STEPID) {
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ts_dev->pen_down = false;
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input_report_key(input_dev, BTN_TOUCH, 0);
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input_report_abs(input_dev, ABS_PRESSURE, 0);
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input_sync(input_dev);
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} else {
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ts_dev->pen_down = true;
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}
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irqclr |= IRQENB_PENUP;
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}
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if (status & IRQENB_HW_PEN) {
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titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
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titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
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}
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if (irqclr) {
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titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
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am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
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return IRQ_HANDLED;
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}
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return IRQ_NONE;
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}
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static int titsc_parse_dt(struct platform_device *pdev,
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struct titsc *ts_dev)
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{
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struct device_node *node = pdev->dev.of_node;
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int err;
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if (!node)
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return -EINVAL;
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err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
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if (err < 0)
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return err;
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switch (ts_dev->wires) {
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case 4:
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case 5:
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case 8:
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break;
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default:
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return -EINVAL;
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}
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err = of_property_read_u32(node, "ti,x-plate-resistance",
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&ts_dev->x_plate_resistance);
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if (err < 0)
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return err;
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/*
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* Try with the new binding first. If it fails, try again with
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* bogus, miss-spelled version.
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*/
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err = of_property_read_u32(node, "ti,coordinate-readouts",
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&ts_dev->coordinate_readouts);
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if (err < 0) {
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dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
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err = of_property_read_u32(node, "ti,coordiante-readouts",
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&ts_dev->coordinate_readouts);
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}
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if (err < 0)
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return err;
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return of_property_read_u32_array(node, "ti,wire-config",
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ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
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}
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/*
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* The functions for inserting/removing driver as a module.
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*/
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static int titsc_probe(struct platform_device *pdev)
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{
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struct titsc *ts_dev;
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struct input_dev *input_dev;
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struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
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int err;
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/* Allocate memory for device */
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ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
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input_dev = input_allocate_device();
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if (!ts_dev || !input_dev) {
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dev_err(&pdev->dev, "failed to allocate memory.\n");
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err = -ENOMEM;
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goto err_free_mem;
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}
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tscadc_dev->tsc = ts_dev;
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ts_dev->mfd_tscadc = tscadc_dev;
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ts_dev->input = input_dev;
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ts_dev->irq = tscadc_dev->irq;
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err = titsc_parse_dt(pdev, ts_dev);
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if (err) {
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dev_err(&pdev->dev, "Could not find valid DT data.\n");
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goto err_free_mem;
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}
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err = request_irq(ts_dev->irq, titsc_irq,
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IRQF_SHARED, pdev->dev.driver->name, ts_dev);
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if (err) {
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dev_err(&pdev->dev, "failed to allocate irq.\n");
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goto err_free_mem;
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}
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titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
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err = titsc_config_wires(ts_dev);
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if (err) {
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dev_err(&pdev->dev, "wrong i/p wire configuration\n");
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goto err_free_irq;
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}
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titsc_step_config(ts_dev);
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titsc_writel(ts_dev, REG_FIFO0THR,
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ts_dev->coordinate_readouts * 2 + 2 - 1);
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input_dev->name = "ti-tsc";
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input_dev->dev.parent = &pdev->dev;
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input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
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input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
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input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
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input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
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input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
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/* register to the input system */
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err = input_register_device(input_dev);
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if (err)
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goto err_free_irq;
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platform_set_drvdata(pdev, ts_dev);
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return 0;
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err_free_irq:
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free_irq(ts_dev->irq, ts_dev);
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err_free_mem:
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input_free_device(input_dev);
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kfree(ts_dev);
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return err;
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}
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static int titsc_remove(struct platform_device *pdev)
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{
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struct titsc *ts_dev = platform_get_drvdata(pdev);
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u32 steps;
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free_irq(ts_dev->irq, ts_dev);
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/* total steps followed by the enable mask */
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steps = 2 * ts_dev->coordinate_readouts + 2;
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steps = (1 << steps) - 1;
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am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
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input_unregister_device(ts_dev->input);
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kfree(ts_dev);
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return 0;
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}
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#ifdef CONFIG_PM
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static int titsc_suspend(struct device *dev)
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{
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struct titsc *ts_dev = dev_get_drvdata(dev);
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struct ti_tscadc_dev *tscadc_dev;
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unsigned int idle;
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tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
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if (device_may_wakeup(tscadc_dev->dev)) {
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idle = titsc_readl(ts_dev, REG_IRQENABLE);
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titsc_writel(ts_dev, REG_IRQENABLE,
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(idle | IRQENB_HW_PEN));
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titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
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}
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return 0;
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}
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static int titsc_resume(struct device *dev)
|
|
{
|
|
struct titsc *ts_dev = dev_get_drvdata(dev);
|
|
struct ti_tscadc_dev *tscadc_dev;
|
|
|
|
tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
|
|
if (device_may_wakeup(tscadc_dev->dev)) {
|
|
titsc_writel(ts_dev, REG_IRQWAKEUP,
|
|
0x00);
|
|
titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
|
|
}
|
|
titsc_step_config(ts_dev);
|
|
titsc_writel(ts_dev, REG_FIFO0THR,
|
|
ts_dev->coordinate_readouts * 2 + 2 - 1);
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pm_ops titsc_pm_ops = {
|
|
.suspend = titsc_suspend,
|
|
.resume = titsc_resume,
|
|
};
|
|
#define TITSC_PM_OPS (&titsc_pm_ops)
|
|
#else
|
|
#define TITSC_PM_OPS NULL
|
|
#endif
|
|
|
|
static const struct of_device_id ti_tsc_dt_ids[] = {
|
|
{ .compatible = "ti,am3359-tsc", },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
|
|
|
|
static struct platform_driver ti_tsc_driver = {
|
|
.probe = titsc_probe,
|
|
.remove = titsc_remove,
|
|
.driver = {
|
|
.name = "TI-am335x-tsc",
|
|
.owner = THIS_MODULE,
|
|
.pm = TITSC_PM_OPS,
|
|
.of_match_table = ti_tsc_dt_ids,
|
|
},
|
|
};
|
|
module_platform_driver(ti_tsc_driver);
|
|
|
|
MODULE_DESCRIPTION("TI touchscreen controller driver");
|
|
MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
|
|
MODULE_LICENSE("GPL");
|