| /* |
| * drivers/input/touchscreen/tsc2007.c |
| * |
| * Copyright (c) 2008 MtekVision Co., Ltd. |
| * Kwangwoo Lee <kwlee@mtekvision.com> |
| * |
| * Using code from: |
| * - ads7846.c |
| * Copyright (c) 2005 David Brownell |
| * Copyright (c) 2006 Nokia Corporation |
| * - corgi_ts.c |
| * Copyright (C) 2004-2005 Richard Purdie |
| * - omap_ts.[hc], ads7846.h, ts_osk.c |
| * Copyright (C) 2002 MontaVista Software |
| * Copyright (C) 2004 Texas Instruments |
| * Copyright (C) 2005 Dirk Behme |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/input.h> |
| #include <linux/interrupt.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c/tsc2007.h> |
| |
| #define TSC2007_MEASURE_TEMP0 (0x0 << 4) |
| #define TSC2007_MEASURE_AUX (0x2 << 4) |
| #define TSC2007_MEASURE_TEMP1 (0x4 << 4) |
| #define TSC2007_ACTIVATE_XN (0x8 << 4) |
| #define TSC2007_ACTIVATE_YN (0x9 << 4) |
| #define TSC2007_ACTIVATE_YP_XN (0xa << 4) |
| #define TSC2007_SETUP (0xb << 4) |
| #define TSC2007_MEASURE_X (0xc << 4) |
| #define TSC2007_MEASURE_Y (0xd << 4) |
| #define TSC2007_MEASURE_Z1 (0xe << 4) |
| #define TSC2007_MEASURE_Z2 (0xf << 4) |
| |
| #define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2) |
| #define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2) |
| #define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2) |
| #define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2) |
| |
| #define TSC2007_12BIT (0x0 << 1) |
| #define TSC2007_8BIT (0x1 << 1) |
| |
| #define MAX_12BIT ((1 << 12) - 1) |
| |
| #define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0) |
| |
| #define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y) |
| #define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1) |
| #define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2) |
| #define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X) |
| #define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN) |
| |
| struct ts_event { |
| u16 x; |
| u16 y; |
| u16 z1, z2; |
| }; |
| |
| struct tsc2007 { |
| struct input_dev *input; |
| char phys[32]; |
| |
| struct i2c_client *client; |
| |
| u16 model; |
| u16 x_plate_ohms; |
| u16 max_rt; |
| unsigned long poll_delay; |
| unsigned long poll_period; |
| |
| int irq; |
| |
| wait_queue_head_t wait; |
| bool stopped; |
| |
| int (*get_pendown_state)(void); |
| void (*clear_penirq)(void); |
| }; |
| |
| static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd) |
| { |
| s32 data; |
| u16 val; |
| |
| data = i2c_smbus_read_word_data(tsc->client, cmd); |
| if (data < 0) { |
| dev_err(&tsc->client->dev, "i2c io error: %d\n", data); |
| return data; |
| } |
| |
| /* The protocol and raw data format from i2c interface: |
| * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P |
| * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit]. |
| */ |
| val = swab16(data) >> 4; |
| |
| dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val); |
| |
| return val; |
| } |
| |
| static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc) |
| { |
| /* y- still on; turn on only y+ (and ADC) */ |
| tc->y = tsc2007_xfer(tsc, READ_Y); |
| |
| /* turn y- off, x+ on, then leave in lowpower */ |
| tc->x = tsc2007_xfer(tsc, READ_X); |
| |
| /* turn y+ off, x- on; we'll use formula #1 */ |
| tc->z1 = tsc2007_xfer(tsc, READ_Z1); |
| tc->z2 = tsc2007_xfer(tsc, READ_Z2); |
| |
| /* Prepare for next touch reading - power down ADC, enable PENIRQ */ |
| tsc2007_xfer(tsc, PWRDOWN); |
| } |
| |
| static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc) |
| { |
| u32 rt = 0; |
| |
| /* range filtering */ |
| if (tc->x == MAX_12BIT) |
| tc->x = 0; |
| |
| if (likely(tc->x && tc->z1)) { |
| /* compute touch pressure resistance using equation #1 */ |
| rt = tc->z2 - tc->z1; |
| rt *= tc->x; |
| rt *= tsc->x_plate_ohms; |
| rt /= tc->z1; |
| rt = (rt + 2047) >> 12; |
| } |
| |
| return rt; |
| } |
| |
| static bool tsc2007_is_pen_down(struct tsc2007 *ts) |
| { |
| /* |
| * NOTE: We can't rely on the pressure to determine the pen down |
| * state, even though this controller has a pressure sensor. |
| * The pressure value can fluctuate for quite a while after |
| * lifting the pen and in some cases may not even settle at the |
| * expected value. |
| * |
| * The only safe way to check for the pen up condition is in the |
| * work function by reading the pen signal state (it's a GPIO |
| * and IRQ). Unfortunately such callback is not always available, |
| * in that case we assume that the pen is down and expect caller |
| * to fall back on the pressure reading. |
| */ |
| |
| if (!ts->get_pendown_state) |
| return true; |
| |
| return ts->get_pendown_state(); |
| } |
| |
| static irqreturn_t tsc2007_soft_irq(int irq, void *handle) |
| { |
| struct tsc2007 *ts = handle; |
| struct input_dev *input = ts->input; |
| struct ts_event tc; |
| u32 rt; |
| |
| while (!ts->stopped && tsc2007_is_pen_down(ts)) { |
| |
| /* pen is down, continue with the measurement */ |
| tsc2007_read_values(ts, &tc); |
| |
| rt = tsc2007_calculate_pressure(ts, &tc); |
| |
| if (rt == 0 && !ts->get_pendown_state) { |
| /* |
| * If pressure reported is 0 and we don't have |
| * callback to check pendown state, we have to |
| * assume that pen was lifted up. |
| */ |
| break; |
| } |
| |
| if (rt <= ts->max_rt) { |
| dev_dbg(&ts->client->dev, |
| "DOWN point(%4d,%4d), pressure (%4u)\n", |
| tc.x, tc.y, rt); |
| |
| input_report_key(input, BTN_TOUCH, 1); |
| input_report_abs(input, ABS_X, tc.x); |
| input_report_abs(input, ABS_Y, tc.y); |
| input_report_abs(input, ABS_PRESSURE, rt); |
| |
| input_sync(input); |
| |
| } else { |
| /* |
| * Sample found inconsistent by debouncing or pressure is |
| * beyond the maximum. Don't report it to user space, |
| * repeat at least once more the measurement. |
| */ |
| dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt); |
| } |
| |
| wait_event_timeout(ts->wait, ts->stopped, |
| msecs_to_jiffies(ts->poll_period)); |
| } |
| |
| dev_dbg(&ts->client->dev, "UP\n"); |
| |
| input_report_key(input, BTN_TOUCH, 0); |
| input_report_abs(input, ABS_PRESSURE, 0); |
| input_sync(input); |
| |
| if (ts->clear_penirq) |
| ts->clear_penirq(); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t tsc2007_hard_irq(int irq, void *handle) |
| { |
| struct tsc2007 *ts = handle; |
| |
| if (!ts->get_pendown_state || likely(ts->get_pendown_state())) |
| return IRQ_WAKE_THREAD; |
| |
| if (ts->clear_penirq) |
| ts->clear_penirq(); |
| |
| return IRQ_HANDLED; |
| } |
| |
| static void tsc2007_stop(struct tsc2007 *ts) |
| { |
| ts->stopped = true; |
| mb(); |
| wake_up(&ts->wait); |
| |
| disable_irq(ts->irq); |
| } |
| |
| static int tsc2007_open(struct input_dev *input_dev) |
| { |
| struct tsc2007 *ts = input_get_drvdata(input_dev); |
| int err; |
| |
| ts->stopped = false; |
| mb(); |
| |
| enable_irq(ts->irq); |
| |
| /* Prepare for touch readings - power down ADC and enable PENIRQ */ |
| err = tsc2007_xfer(ts, PWRDOWN); |
| if (err < 0) { |
| tsc2007_stop(ts); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static void tsc2007_close(struct input_dev *input_dev) |
| { |
| struct tsc2007 *ts = input_get_drvdata(input_dev); |
| |
| tsc2007_stop(ts); |
| } |
| |
| static int __devinit tsc2007_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct tsc2007 *ts; |
| struct tsc2007_platform_data *pdata = client->dev.platform_data; |
| struct input_dev *input_dev; |
| int err; |
| |
| if (!pdata) { |
| dev_err(&client->dev, "platform data is required!\n"); |
| return -EINVAL; |
| } |
| |
| if (!i2c_check_functionality(client->adapter, |
| I2C_FUNC_SMBUS_READ_WORD_DATA)) |
| return -EIO; |
| |
| ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL); |
| input_dev = input_allocate_device(); |
| if (!ts || !input_dev) { |
| err = -ENOMEM; |
| goto err_free_mem; |
| } |
| |
| ts->client = client; |
| ts->irq = client->irq; |
| ts->input = input_dev; |
| init_waitqueue_head(&ts->wait); |
| |
| ts->model = pdata->model; |
| ts->x_plate_ohms = pdata->x_plate_ohms; |
| ts->max_rt = pdata->max_rt ? : MAX_12BIT; |
| ts->poll_delay = pdata->poll_delay ? : 1; |
| ts->poll_period = pdata->poll_period ? : 1; |
| ts->get_pendown_state = pdata->get_pendown_state; |
| ts->clear_penirq = pdata->clear_penirq; |
| |
| snprintf(ts->phys, sizeof(ts->phys), |
| "%s/input0", dev_name(&client->dev)); |
| |
| input_dev->name = "TSC2007 Touchscreen"; |
| input_dev->phys = ts->phys; |
| input_dev->id.bustype = BUS_I2C; |
| |
| input_dev->open = tsc2007_open; |
| input_dev->close = tsc2007_close; |
| |
| input_set_drvdata(input_dev, ts); |
| |
| input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); |
| input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); |
| |
| input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, pdata->fuzzx, 0); |
| input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, pdata->fuzzy, 0); |
| input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, |
| pdata->fuzzz, 0); |
| |
| if (pdata->init_platform_hw) |
| pdata->init_platform_hw(); |
| |
| err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq, |
| IRQF_ONESHOT, client->dev.driver->name, ts); |
| if (err < 0) { |
| dev_err(&client->dev, "irq %d busy?\n", ts->irq); |
| goto err_free_mem; |
| } |
| |
| tsc2007_stop(ts); |
| |
| err = input_register_device(input_dev); |
| if (err) |
| goto err_free_irq; |
| |
| i2c_set_clientdata(client, ts); |
| |
| return 0; |
| |
| err_free_irq: |
| free_irq(ts->irq, ts); |
| if (pdata->exit_platform_hw) |
| pdata->exit_platform_hw(); |
| err_free_mem: |
| input_free_device(input_dev); |
| kfree(ts); |
| return err; |
| } |
| |
| static int __devexit tsc2007_remove(struct i2c_client *client) |
| { |
| struct tsc2007 *ts = i2c_get_clientdata(client); |
| struct tsc2007_platform_data *pdata = client->dev.platform_data; |
| |
| free_irq(ts->irq, ts); |
| |
| if (pdata->exit_platform_hw) |
| pdata->exit_platform_hw(); |
| |
| input_unregister_device(ts->input); |
| kfree(ts); |
| |
| return 0; |
| } |
| |
| static const struct i2c_device_id tsc2007_idtable[] = { |
| { "tsc2007", 0 }, |
| { } |
| }; |
| |
| MODULE_DEVICE_TABLE(i2c, tsc2007_idtable); |
| |
| static struct i2c_driver tsc2007_driver = { |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = "tsc2007" |
| }, |
| .id_table = tsc2007_idtable, |
| .probe = tsc2007_probe, |
| .remove = __devexit_p(tsc2007_remove), |
| }; |
| |
| static int __init tsc2007_init(void) |
| { |
| return i2c_add_driver(&tsc2007_driver); |
| } |
| |
| static void __exit tsc2007_exit(void) |
| { |
| i2c_del_driver(&tsc2007_driver); |
| } |
| |
| module_init(tsc2007_init); |
| module_exit(tsc2007_exit); |
| |
| MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>"); |
| MODULE_DESCRIPTION("TSC2007 TouchScreen Driver"); |
| MODULE_LICENSE("GPL"); |