487 строки
12 KiB
C
487 строки
12 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_tscadc.h>
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#include <linux/delay.h>
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#define REG_IRQEOI 0x020
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#define REG_RAWIRQSTATUS 0x024
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#define REG_IRQSTATUS 0x028
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#define REG_IRQENABLE 0x02C
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#define REG_IRQWAKEUP 0x034
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#define REG_CTRL 0x040
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#define REG_ADCFSM 0x044
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#define REG_CLKDIV 0x04C
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#define REG_SE 0x054
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#define REG_IDLECONFIG 0x058
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#define REG_CHARGECONFIG 0x05C
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#define REG_CHARGEDELAY 0x060
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#define REG_STEPCONFIG(n) (0x64 + ((n - 1) * 8))
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#define REG_STEPDELAY(n) (0x68 + ((n - 1) * 8))
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#define REG_STEPCONFIG13 0x0C4
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#define REG_STEPDELAY13 0x0C8
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#define REG_STEPCONFIG14 0x0CC
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#define REG_STEPDELAY14 0x0D0
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#define REG_FIFO0CNT 0xE4
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#define REG_FIFO1THR 0xF4
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#define REG_FIFO0 0x100
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#define REG_FIFO1 0x200
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/* Register Bitfields */
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#define IRQWKUP_ENB BIT(0)
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#define STPENB_STEPENB 0x7FFF
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#define IRQENB_FIFO1THRES BIT(5)
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#define IRQENB_PENUP BIT(9)
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#define STEPCONFIG_MODE_HWSYNC 0x2
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#define STEPCONFIG_SAMPLES_AVG (1 << 4)
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#define STEPCONFIG_XPP (1 << 5)
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#define STEPCONFIG_XNN (1 << 6)
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#define STEPCONFIG_YPP (1 << 7)
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#define STEPCONFIG_YNN (1 << 8)
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#define STEPCONFIG_XNP (1 << 9)
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#define STEPCONFIG_YPN (1 << 10)
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#define STEPCONFIG_INM (1 << 18)
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#define STEPCONFIG_INP (1 << 20)
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#define STEPCONFIG_INP_5 (1 << 21)
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#define STEPCONFIG_FIFO1 (1 << 26)
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#define STEPCONFIG_OPENDLY 0xff
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#define STEPCONFIG_Z1 (3 << 19)
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#define STEPIDLE_INP (1 << 22)
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#define STEPCHARGE_RFP (1 << 12)
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#define STEPCHARGE_INM (1 << 15)
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#define STEPCHARGE_INP (1 << 19)
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#define STEPCHARGE_RFM (1 << 23)
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#define STEPCHARGE_DELAY 0x1
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#define CNTRLREG_TSCSSENB (1 << 0)
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#define CNTRLREG_STEPID (1 << 1)
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#define CNTRLREG_STEPCONFIGWRT (1 << 2)
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#define CNTRLREG_4WIRE (1 << 5)
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#define CNTRLREG_5WIRE (1 << 6)
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#define CNTRLREG_8WIRE (3 << 5)
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#define CNTRLREG_TSCENB (1 << 7)
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#define ADCFSM_STEPID 0x10
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#define SEQ_SETTLE 275
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#define ADC_CLK 3000000
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#define MAX_12BIT ((1 << 12) - 1)
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#define TSCADC_DELTA_X 15
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#define TSCADC_DELTA_Y 15
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struct tscadc {
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struct input_dev *input;
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struct clk *tsc_ick;
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void __iomem *tsc_base;
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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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};
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static unsigned int tscadc_readl(struct tscadc *ts, unsigned int reg)
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{
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return readl(ts->tsc_base + reg);
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}
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static void tscadc_writel(struct tscadc *tsc, unsigned int reg,
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unsigned int val)
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{
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writel(val, tsc->tsc_base + reg);
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}
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static void tscadc_step_config(struct tscadc *ts_dev)
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{
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unsigned int config;
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int i;
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/* Configure the Step registers */
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config = STEPCONFIG_MODE_HWSYNC |
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STEPCONFIG_SAMPLES_AVG | STEPCONFIG_XPP;
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switch (ts_dev->wires) {
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case 4:
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config |= STEPCONFIG_INP | 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_5 | 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 | STEPCONFIG_XNN;
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break;
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}
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for (i = 1; i < 7; i++) {
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tscadc_writel(ts_dev, REG_STEPCONFIG(i), config);
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tscadc_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_SAMPLES_AVG | STEPCONFIG_YNN |
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STEPCONFIG_INM | 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_5 |
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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 = 7; i < 13; i++) {
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tscadc_writel(ts_dev, REG_STEPCONFIG(i), config);
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tscadc_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 | STEPCHARGE_RFM |
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STEPCHARGE_INM | STEPCHARGE_INP;
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tscadc_writel(ts_dev, REG_CHARGECONFIG, config);
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tscadc_writel(ts_dev, REG_CHARGEDELAY, STEPCHARGE_DELAY);
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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_SAMPLES_AVG | STEPCONFIG_YPP |
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STEPCONFIG_XNN | STEPCONFIG_INM;
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tscadc_writel(ts_dev, REG_STEPCONFIG13, config);
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tscadc_writel(ts_dev, REG_STEPDELAY13, STEPCONFIG_OPENDLY);
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config |= STEPCONFIG_Z1 | STEPCONFIG_FIFO1;
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tscadc_writel(ts_dev, REG_STEPCONFIG14, config);
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tscadc_writel(ts_dev, REG_STEPDELAY14, STEPCONFIG_OPENDLY);
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tscadc_writel(ts_dev, REG_SE, STPENB_STEPENB);
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}
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static void tscadc_idle_config(struct tscadc *ts_config)
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{
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unsigned int idleconfig;
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idleconfig = STEPCONFIG_YNN |
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STEPCONFIG_INM |
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STEPCONFIG_YPN | STEPIDLE_INP;
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tscadc_writel(ts_config, REG_IDLECONFIG, idleconfig);
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}
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static void tscadc_read_coordinates(struct tscadc *ts_dev,
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unsigned int *x, unsigned int *y)
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{
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unsigned int fifocount = tscadc_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;
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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 = tscadc_readl(ts_dev, REG_FIFO0) & 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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read = tscadc_readl(ts_dev, REG_FIFO1) & 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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static irqreturn_t tscadc_irq(int irq, void *dev)
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{
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struct tscadc *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 = tscadc_readl(ts_dev, REG_IRQSTATUS);
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if (status & IRQENB_FIFO1THRES) {
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tscadc_read_coordinates(ts_dev, &x, &y);
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z1 = tscadc_readl(ts_dev, REG_FIFO0) & 0xfff;
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z2 = tscadc_readl(ts_dev, REG_FIFO1) & 0xfff;
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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_FIFO1THRES;
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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 = tscadc_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 = tscadc_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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tscadc_writel(ts_dev, REG_IRQSTATUS, irqclr);
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/* check pending interrupts */
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tscadc_writel(ts_dev, REG_IRQEOI, 0x0);
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tscadc_writel(ts_dev, REG_SE, STPENB_STEPENB);
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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 __devinit tscadc_probe(struct platform_device *pdev)
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{
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const struct tsc_data *pdata = pdev->dev.platform_data;
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struct resource *res;
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struct tscadc *ts_dev;
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struct input_dev *input_dev;
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struct clk *clk;
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int err;
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int clk_value, ctrl, irq;
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if (!pdata) {
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dev_err(&pdev->dev, "missing platform data.\n");
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return -EINVAL;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "no memory resource defined.\n");
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return -EINVAL;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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dev_err(&pdev->dev, "no irq ID is specified.\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 tscadc), 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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ts_dev->input = input_dev;
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ts_dev->irq = irq;
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ts_dev->wires = pdata->wires;
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ts_dev->x_plate_resistance = pdata->x_plate_resistance;
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res = request_mem_region(res->start, resource_size(res), pdev->name);
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if (!res) {
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dev_err(&pdev->dev, "failed to reserve registers.\n");
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err = -EBUSY;
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goto err_free_mem;
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}
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ts_dev->tsc_base = ioremap(res->start, resource_size(res));
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if (!ts_dev->tsc_base) {
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dev_err(&pdev->dev, "failed to map registers.\n");
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err = -ENOMEM;
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goto err_release_mem_region;
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}
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err = request_irq(ts_dev->irq, tscadc_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_unmap_regs;
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}
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ts_dev->tsc_ick = clk_get(&pdev->dev, "adc_tsc_ick");
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if (IS_ERR(ts_dev->tsc_ick)) {
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dev_err(&pdev->dev, "failed to get TSC ick\n");
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goto err_free_irq;
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}
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clk_enable(ts_dev->tsc_ick);
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clk = clk_get(&pdev->dev, "adc_tsc_fck");
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if (IS_ERR(clk)) {
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dev_err(&pdev->dev, "failed to get TSC fck\n");
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err = PTR_ERR(clk);
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goto err_disable_clk;
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}
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clk_value = clk_get_rate(clk) / ADC_CLK;
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clk_put(clk);
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if (clk_value < 7) {
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dev_err(&pdev->dev, "clock input less than min clock requirement\n");
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goto err_disable_clk;
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}
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/* CLKDIV needs to be configured to the value minus 1 */
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tscadc_writel(ts_dev, REG_CLKDIV, clk_value - 1);
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/* Enable wake-up of the SoC using touchscreen */
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tscadc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
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ctrl = CNTRLREG_STEPCONFIGWRT |
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CNTRLREG_TSCENB |
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CNTRLREG_STEPID;
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switch (ts_dev->wires) {
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case 4:
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ctrl |= CNTRLREG_4WIRE;
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break;
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case 5:
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ctrl |= CNTRLREG_5WIRE;
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break;
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case 8:
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ctrl |= CNTRLREG_8WIRE;
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break;
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}
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tscadc_writel(ts_dev, REG_CTRL, ctrl);
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tscadc_idle_config(ts_dev);
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tscadc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO1THRES);
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tscadc_step_config(ts_dev);
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tscadc_writel(ts_dev, REG_FIFO1THR, 6);
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ctrl |= CNTRLREG_TSCSSENB;
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tscadc_writel(ts_dev, REG_CTRL, ctrl);
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input_dev->name = "ti-tsc-adc";
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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_disable_clk;
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platform_set_drvdata(pdev, ts_dev);
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return 0;
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err_disable_clk:
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clk_disable(ts_dev->tsc_ick);
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clk_put(ts_dev->tsc_ick);
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err_free_irq:
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free_irq(ts_dev->irq, ts_dev);
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err_unmap_regs:
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iounmap(ts_dev->tsc_base);
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err_release_mem_region:
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release_mem_region(res->start, resource_size(res));
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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 __devexit tscadc_remove(struct platform_device *pdev)
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{
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struct tscadc *ts_dev = platform_get_drvdata(pdev);
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struct resource *res;
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free_irq(ts_dev->irq, ts_dev);
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input_unregister_device(ts_dev->input);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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iounmap(ts_dev->tsc_base);
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release_mem_region(res->start, resource_size(res));
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clk_disable(ts_dev->tsc_ick);
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clk_put(ts_dev->tsc_ick);
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kfree(ts_dev);
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platform_set_drvdata(pdev, NULL);
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver ti_tsc_driver = {
|
|
.probe = tscadc_probe,
|
|
.remove = __devexit_p(tscadc_remove),
|
|
.driver = {
|
|
.name = "tsc",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
module_platform_driver(ti_tsc_driver);
|
|
|
|
MODULE_DESCRIPTION("TI touchscreen controller driver");
|
|
MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
|
|
MODULE_LICENSE("GPL");
|