abeccee403
Current code has hard coded value written to step enable bits. Now the bits are updated based on how many steps are needed to be configured got from platform data. The user needs to take care not to exceed the count more than 16. While using ADC and TSC one should take care to set this parameter correctly. Sebastian added the common lock and moved the code, that manipulates the steps, from into the mfd module. Signed-off-by: Patil, Rachna <rachna@ti.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
409 lines
11 KiB
C
409 lines
11 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/init.h>
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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/input/ti_am335x_tsc.h>
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#include <linux/delay.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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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 steps_to_configure;
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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 void titsc_step_config(struct titsc *ts_dev)
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{
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unsigned int config;
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unsigned int stepenable = 0;
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int i, total_steps;
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/* Configure the Step registers */
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total_steps = 2 * ts_dev->steps_to_configure;
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config = STEPCONFIG_MODE_HWSYNC |
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STEPCONFIG_AVG_16 | STEPCONFIG_XPP;
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switch (ts_dev->wires) {
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case 4:
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config |= STEPCONFIG_INP_AN2 | STEPCONFIG_XNN;
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break;
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case 5:
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config |= STEPCONFIG_YNN |
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STEPCONFIG_INP_AN4 | STEPCONFIG_XNN |
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STEPCONFIG_YPP;
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break;
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case 8:
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config |= STEPCONFIG_INP_AN2 | STEPCONFIG_XNN;
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break;
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}
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for (i = 1; i <= ts_dev->steps_to_configure; 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 | STEPCONFIG_YNN |
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STEPCONFIG_INM_ADCREFM | STEPCONFIG_FIFO1;
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switch (ts_dev->wires) {
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case 4:
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config |= STEPCONFIG_YPP;
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break;
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case 5:
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config |= STEPCONFIG_XPP | STEPCONFIG_INP_AN4 |
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STEPCONFIG_XNP | STEPCONFIG_YPN;
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break;
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case 8:
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config |= STEPCONFIG_YPP;
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break;
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}
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for (i = (ts_dev->steps_to_configure + 1); i <= total_steps; 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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/* Charge step configuration */
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config = STEPCONFIG_XPP | STEPCONFIG_YNN |
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STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
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STEPCHARGE_INM_AN1 | STEPCHARGE_INP_AN1;
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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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config = 0;
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/* Configure to calculate pressure */
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config = STEPCONFIG_MODE_HWSYNC |
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STEPCONFIG_AVG_16 | STEPCONFIG_YPP |
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STEPCONFIG_XNN | STEPCONFIG_INM_ADCREFM;
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titsc_writel(ts_dev, REG_STEPCONFIG(total_steps + 1), config);
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titsc_writel(ts_dev, REG_STEPDELAY(total_steps + 1),
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STEPCONFIG_OPENDLY);
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config |= STEPCONFIG_INP_AN3 | STEPCONFIG_FIFO1;
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titsc_writel(ts_dev, REG_STEPCONFIG(total_steps + 2), config);
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titsc_writel(ts_dev, REG_STEPDELAY(total_steps + 2),
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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 << (total_steps + 2)) - 1;
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am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable);
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}
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static void titsc_read_coordinates(struct titsc *ts_dev,
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unsigned int *x, unsigned int *y)
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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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/*
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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 - 1; i++) {
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read = titsc_readl(ts_dev, REG_FIFO0);
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channel = read & 0xf0000;
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channel = channel >> 0x10;
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if ((channel >= 0) && (channel < ts_dev->steps_to_configure)) {
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read &= 0xfff;
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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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}
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read = titsc_readl(ts_dev, REG_FIFO1);
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channel = read & 0xf0000;
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channel = channel >> 0x10;
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if ((channel >= ts_dev->steps_to_configure) &&
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(channel < (2 * ts_dev->steps_to_configure - 1))) {
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read &= 0xfff;
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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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}
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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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unsigned int fifo1count, fifo0count;
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int i;
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status = titsc_readl(ts_dev, REG_IRQSTATUS);
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if (status & IRQENB_FIFO0THRES) {
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titsc_read_coordinates(ts_dev, &x, &y);
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z1 = titsc_readl(ts_dev, REG_FIFO0) & 0xfff;
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z2 = titsc_readl(ts_dev, REG_FIFO1) & 0xfff;
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fifo1count = titsc_readl(ts_dev, REG_FIFO1CNT);
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for (i = 0; i < fifo1count; i++)
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titsc_readl(ts_dev, REG_FIFO1);
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fifo0count = titsc_readl(ts_dev, REG_FIFO0CNT);
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for (i = 0; i < fifo0count; i++)
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titsc_readl(ts_dev, REG_FIFO0);
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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 = z2 - z1;
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z *= x;
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z *= ts_dev->x_plate_resistance;
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z /= z1;
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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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titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
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am335x_tsc_se_update(ts_dev->mfd_tscadc);
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return IRQ_HANDLED;
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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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struct mfd_tscadc_board *pdata;
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int err;
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pdata = tscadc_dev->dev->platform_data;
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if (!pdata) {
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dev_err(&pdev->dev, "Could not find platform data\n");
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return -EINVAL;
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}
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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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ts_dev->wires = pdata->tsc_init->wires;
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ts_dev->x_plate_resistance = pdata->tsc_init->x_plate_resistance;
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ts_dev->steps_to_configure = pdata->tsc_init->steps_to_configure;
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err = request_irq(ts_dev->irq, titsc_irq,
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0, 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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titsc_step_config(ts_dev);
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titsc_writel(ts_dev, REG_FIFO0THR, ts_dev->steps_to_configure);
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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->steps_to_configure + 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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platform_set_drvdata(pdev, NULL);
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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)
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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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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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titsc_writel(ts_dev, REG_IRQWAKEUP,
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0x00);
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titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
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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->steps_to_configure);
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return 0;
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}
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static const struct dev_pm_ops titsc_pm_ops = {
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.suspend = titsc_suspend,
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.resume = titsc_resume,
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};
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#define TITSC_PM_OPS (&titsc_pm_ops)
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#else
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#define TITSC_PM_OPS NULL
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#endif
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static struct platform_driver ti_tsc_driver = {
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.probe = titsc_probe,
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.remove = titsc_remove,
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.driver = {
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.name = "tsc",
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.owner = THIS_MODULE,
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.pm = TITSC_PM_OPS,
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},
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};
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module_platform_driver(ti_tsc_driver);
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MODULE_DESCRIPTION("TI touchscreen controller driver");
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MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
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MODULE_LICENSE("GPL");
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