![Márton Németh](/assets/img/avatar_default.png)
The id_table field of the struct i2c_driver is defined as constant in <linux/i2c.h> so it makes sense to mark the initialization data also constant. Signed-off-by: Márton Németh <nm127@freemail.hu> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
394 lines
9.4 KiB
C
394 lines
9.4 KiB
C
/*
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* drivers/input/touchscreen/tsc2007.c
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*
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* Copyright (c) 2008 MtekVision Co., Ltd.
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* Kwangwoo Lee <kwlee@mtekvision.com>
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*
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* Using code from:
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* - ads7846.c
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* Copyright (c) 2005 David Brownell
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* Copyright (c) 2006 Nokia Corporation
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* - corgi_ts.c
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* Copyright (C) 2004-2005 Richard Purdie
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* - omap_ts.[hc], ads7846.h, ts_osk.c
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* Copyright (C) 2002 MontaVista Software
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* Copyright (C) 2004 Texas Instruments
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* Copyright (C) 2005 Dirk Behme
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/i2c/tsc2007.h>
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#define TS_POLL_DELAY 1 /* ms delay between samples */
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#define TS_POLL_PERIOD 1 /* ms delay between samples */
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#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
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#define TSC2007_MEASURE_AUX (0x2 << 4)
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#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
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#define TSC2007_ACTIVATE_XN (0x8 << 4)
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#define TSC2007_ACTIVATE_YN (0x9 << 4)
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#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
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#define TSC2007_SETUP (0xb << 4)
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#define TSC2007_MEASURE_X (0xc << 4)
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#define TSC2007_MEASURE_Y (0xd << 4)
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#define TSC2007_MEASURE_Z1 (0xe << 4)
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#define TSC2007_MEASURE_Z2 (0xf << 4)
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#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
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#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
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#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
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#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
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#define TSC2007_12BIT (0x0 << 1)
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#define TSC2007_8BIT (0x1 << 1)
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#define MAX_12BIT ((1 << 12) - 1)
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#define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
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#define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
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#define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
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#define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
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#define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
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#define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
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struct ts_event {
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u16 x;
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u16 y;
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u16 z1, z2;
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};
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struct tsc2007 {
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struct input_dev *input;
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char phys[32];
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struct delayed_work work;
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struct i2c_client *client;
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u16 model;
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u16 x_plate_ohms;
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bool pendown;
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int irq;
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int (*get_pendown_state)(void);
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void (*clear_penirq)(void);
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};
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static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
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{
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s32 data;
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u16 val;
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data = i2c_smbus_read_word_data(tsc->client, cmd);
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if (data < 0) {
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dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
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return data;
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}
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/* The protocol and raw data format from i2c interface:
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* S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
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* Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
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*/
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val = swab16(data) >> 4;
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dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
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return val;
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}
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static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
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{
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/* y- still on; turn on only y+ (and ADC) */
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tc->y = tsc2007_xfer(tsc, READ_Y);
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/* turn y- off, x+ on, then leave in lowpower */
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tc->x = tsc2007_xfer(tsc, READ_X);
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/* turn y+ off, x- on; we'll use formula #1 */
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tc->z1 = tsc2007_xfer(tsc, READ_Z1);
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tc->z2 = tsc2007_xfer(tsc, READ_Z2);
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/* Prepare for next touch reading - power down ADC, enable PENIRQ */
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tsc2007_xfer(tsc, PWRDOWN);
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}
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static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
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{
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u32 rt = 0;
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/* range filtering */
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if (tc->x == MAX_12BIT)
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tc->x = 0;
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if (likely(tc->x && tc->z1)) {
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/* compute touch pressure resistance using equation #1 */
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rt = tc->z2 - tc->z1;
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rt *= tc->x;
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rt *= tsc->x_plate_ohms;
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rt /= tc->z1;
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rt = (rt + 2047) >> 12;
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}
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return rt;
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}
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static void tsc2007_send_up_event(struct tsc2007 *tsc)
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{
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struct input_dev *input = tsc->input;
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dev_dbg(&tsc->client->dev, "UP\n");
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input_report_key(input, BTN_TOUCH, 0);
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input_report_abs(input, ABS_PRESSURE, 0);
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input_sync(input);
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}
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static void tsc2007_work(struct work_struct *work)
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{
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struct tsc2007 *ts =
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container_of(to_delayed_work(work), struct tsc2007, work);
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struct ts_event tc;
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u32 rt;
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/*
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* NOTE: We can't rely on the pressure to determine the pen down
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* state, even though this controller has a pressure sensor.
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* The pressure value can fluctuate for quite a while after
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* lifting the pen and in some cases may not even settle at the
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* expected value.
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*
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* The only safe way to check for the pen up condition is in the
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* work function by reading the pen signal state (it's a GPIO
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* and IRQ). Unfortunately such callback is not always available,
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* in that case we have rely on the pressure anyway.
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*/
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if (ts->get_pendown_state) {
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if (unlikely(!ts->get_pendown_state())) {
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tsc2007_send_up_event(ts);
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ts->pendown = false;
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goto out;
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}
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dev_dbg(&ts->client->dev, "pen is still down\n");
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}
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tsc2007_read_values(ts, &tc);
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rt = tsc2007_calculate_pressure(ts, &tc);
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if (rt > MAX_12BIT) {
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/*
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* Sample found inconsistent by debouncing or pressure is
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* beyond the maximum. Don't report it to user space,
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* repeat at least once more the measurement.
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*/
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dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
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goto out;
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}
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if (rt) {
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struct input_dev *input = ts->input;
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if (!ts->pendown) {
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dev_dbg(&ts->client->dev, "DOWN\n");
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input_report_key(input, BTN_TOUCH, 1);
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ts->pendown = true;
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}
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input_report_abs(input, ABS_X, tc.x);
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input_report_abs(input, ABS_Y, tc.y);
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input_report_abs(input, ABS_PRESSURE, rt);
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input_sync(input);
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dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
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tc.x, tc.y, rt);
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} else if (!ts->get_pendown_state && ts->pendown) {
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/*
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* We don't have callback to check pendown state, so we
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* have to assume that since pressure reported is 0 the
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* pen was lifted up.
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*/
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tsc2007_send_up_event(ts);
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ts->pendown = false;
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}
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out:
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if (ts->pendown)
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schedule_delayed_work(&ts->work,
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msecs_to_jiffies(TS_POLL_PERIOD));
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else
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enable_irq(ts->irq);
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}
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static irqreturn_t tsc2007_irq(int irq, void *handle)
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{
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struct tsc2007 *ts = handle;
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if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {
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disable_irq_nosync(ts->irq);
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schedule_delayed_work(&ts->work,
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msecs_to_jiffies(TS_POLL_DELAY));
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}
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if (ts->clear_penirq)
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ts->clear_penirq();
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return IRQ_HANDLED;
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}
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static void tsc2007_free_irq(struct tsc2007 *ts)
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{
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free_irq(ts->irq, ts);
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if (cancel_delayed_work_sync(&ts->work)) {
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/*
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* Work was pending, therefore we need to enable
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* IRQ here to balance the disable_irq() done in the
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* interrupt handler.
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*/
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enable_irq(ts->irq);
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}
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}
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static int __devinit tsc2007_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct tsc2007 *ts;
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struct tsc2007_platform_data *pdata = pdata = client->dev.platform_data;
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struct input_dev *input_dev;
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int err;
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if (!pdata) {
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dev_err(&client->dev, "platform data is required!\n");
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return -EINVAL;
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}
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if (!i2c_check_functionality(client->adapter,
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I2C_FUNC_SMBUS_READ_WORD_DATA))
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return -EIO;
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ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
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input_dev = input_allocate_device();
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if (!ts || !input_dev) {
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err = -ENOMEM;
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goto err_free_mem;
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}
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ts->client = client;
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ts->irq = client->irq;
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ts->input = input_dev;
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INIT_DELAYED_WORK(&ts->work, tsc2007_work);
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ts->model = pdata->model;
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ts->x_plate_ohms = pdata->x_plate_ohms;
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ts->get_pendown_state = pdata->get_pendown_state;
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ts->clear_penirq = pdata->clear_penirq;
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snprintf(ts->phys, sizeof(ts->phys),
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"%s/input0", dev_name(&client->dev));
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input_dev->name = "TSC2007 Touchscreen";
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input_dev->phys = ts->phys;
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input_dev->id.bustype = BUS_I2C;
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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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if (pdata->init_platform_hw)
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pdata->init_platform_hw();
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err = request_irq(ts->irq, tsc2007_irq, 0,
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client->dev.driver->name, ts);
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if (err < 0) {
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dev_err(&client->dev, "irq %d busy?\n", ts->irq);
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goto err_free_mem;
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}
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/* Prepare for touch readings - power down ADC and enable PENIRQ */
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err = tsc2007_xfer(ts, PWRDOWN);
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if (err < 0)
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goto err_free_irq;
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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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i2c_set_clientdata(client, ts);
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return 0;
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err_free_irq:
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tsc2007_free_irq(ts);
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if (pdata->exit_platform_hw)
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pdata->exit_platform_hw();
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err_free_mem:
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input_free_device(input_dev);
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kfree(ts);
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return err;
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}
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static int __devexit tsc2007_remove(struct i2c_client *client)
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{
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struct tsc2007 *ts = i2c_get_clientdata(client);
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struct tsc2007_platform_data *pdata = client->dev.platform_data;
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tsc2007_free_irq(ts);
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if (pdata->exit_platform_hw)
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pdata->exit_platform_hw();
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input_unregister_device(ts->input);
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kfree(ts);
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return 0;
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}
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static const struct i2c_device_id tsc2007_idtable[] = {
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{ "tsc2007", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
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static struct i2c_driver tsc2007_driver = {
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.driver = {
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.owner = THIS_MODULE,
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.name = "tsc2007"
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},
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.id_table = tsc2007_idtable,
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.probe = tsc2007_probe,
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.remove = __devexit_p(tsc2007_remove),
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};
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static int __init tsc2007_init(void)
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{
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return i2c_add_driver(&tsc2007_driver);
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}
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static void __exit tsc2007_exit(void)
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{
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i2c_del_driver(&tsc2007_driver);
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}
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module_init(tsc2007_init);
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module_exit(tsc2007_exit);
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MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
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MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
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MODULE_LICENSE("GPL");
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