/* * drivers/input/touchscreen/tsc2007-gta04.c * * Copyright (c) 2008 MtekVision Co., Ltd. * Kwangwoo Lee * * 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 * Copyright (C) 2011 Nikolaus Schaller - gta04 extensions (/sys entry, sample AUX & TEMP even if touch is not down) * * 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 #include #include #include #include #include #define TS_POLL_DELAY 1 /* ms delay between IRQ and first sample */ #define TS_POLL_PERIOD 1 /* ms delay between samples */ #define TS_AUX_POLL_PERIOD 100 /* ms delay between samples of AUX, TEMP1, TEMP2 */ #define TS_VREF 1800 /* in mV - should have been defined in the board file! */ #define JITTER_HISTO 5 /* number of historic values to keep */ #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_SETUP_PULLUP_90K 0x01 #define TSC2007_SETUP_BYPASS_MAV 0x02 #define TSC2007_MEASURE_TEMP0 (0x0 << 4) #define TSC2007_MEASURE_AUX (0x2 << 4) #define TSC2007_MEASURE_TEMP1 (0x4 << 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 READ_TEMP0 (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0) #define READ_TEMP1 (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1) #define READ_AUX (ADC_ON_12BIT | TSC2007_MEASURE_AUX) #define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN) struct ts_event { u16 x; u16 y; u16 z1, z2; }; struct jitterbug { s32 val; /* history of input values */ s32 out; /* history of output values */ }; struct tsc2007 { struct input_dev *input; char phys[32]; struct delayed_work work; struct delayed_work aux_work; struct i2c_client *client; u16 model; u16 x_plate_ohms; u16 min_x; u16 min_y; u16 min_z; u16 max_x; u16 max_y; u16 max_z; bool flip_x; bool flip_y; bool swap_xy; bool pendown; int irq; int (*get_pendown_state)(void); void (*clear_penirq)(void); struct ts_event tc; int aux_counter; s16 temperature; /* in degrees C */ u16 temp0; u16 temp1; u16 aux; u16 pressure; struct jitterbug jitterbufx[JITTER_HISTO]; struct jitterbug jitterbufy[JITTER_HISTO]; }; /* /sys extension to access TEMP and AUX and many other values */ static ssize_t show_data(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); struct tsc2007 *ts = i2c_get_clientdata(client); return sprintf(buf, "%u,%u,%u,%d,%d,%u,%u,%u,%u,%u,%u\n", ts->tc.x, ts->tc.y, ts->pressure, ts->pendown, ts->temperature, ts->tc.z1, ts->tc.z2, ts->temp0, ts->temp1, ts->aux, ts->pressure > 0 ? ((4096/16) * (u32)ts->x_plate_ohms) / ts->pressure : 65535); } static DEVICE_ATTR(values, S_IRUGO, show_data, NULL); static struct attribute *tsc2007_attributes[] = { &dev_attr_values.attr, NULL }; static const struct attribute_group tsc2007_attr_group = { .attrs = tsc2007_attributes, }; /* i2c/smbus access */ static inline int tsc2007_xfer(struct tsc2007 *ts, u8 cmd) { s32 data; u16 val; data = i2c_smbus_read_word_data(ts->client, cmd); if (data < 0) { dev_err(&ts->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(&ts->client->dev, "data: 0x%x, val: 0x%x\n", data, val); return val; } static void tsc2007_read_temp(struct tsc2007 *ts) { u32 v1, v2; /* voltage in mV */ ts->temp0 = tsc2007_xfer(ts, READ_TEMP0); ts->temp1 = tsc2007_xfer(ts, READ_TEMP1); v1 = (TS_VREF * (u32)ts->temp0) / 4096; v2 = (TS_VREF * (u32)ts->temp1) / 4096; ts->temperature = (2573 * (v2-v1)) / 100 - 2730; /* in tenths of degrees C */ ts->aux = tsc2007_xfer(ts, READ_AUX); ts->aux_counter=0; } static void tsc2007_read_values(struct tsc2007 *ts) { /* y- still on; turn on only y+ (and ADC) */ ts->tc.y = tsc2007_xfer(ts, READ_Y); /* turn y- off, x+ on, then leave in lowpower */ ts->tc.x = tsc2007_xfer(ts, READ_X); /* turn y+ off, x- on; we'll use formula #1 */ ts->tc.z1 = tsc2007_xfer(ts, READ_Z1); ts->tc.z2 = tsc2007_xfer(ts, READ_Z2); /* keep slowly updating while we don't have scheduled the aux_work */ if(ts->aux_counter++ >= (TS_AUX_POLL_PERIOD/TS_POLL_PERIOD)) tsc2007_read_temp(ts); /* Prepare for next touch reading - power down ADC, enable PENIRQ */ tsc2007_xfer(ts, PWRDOWN); } static u16 tsc2007_calculate_pressure(struct tsc2007 *ts) { u32 rt = 0; /* range filtering */ if (ts->tc.x >= MAX_12BIT) return rt; if (likely(ts->tc.x && ts->tc.z1 && ts->tc.z2 > ts->tc.z1)) { /* compute touch pressure resistance using equation #1 */ /* and translate into increasing pressure for decreasing resistance */ rt = ((u32) ts->tc.z1) << (32 - 12); /* shift to maximum precision */ rt /= (ts->tc.x * (u32)(ts->tc.z2 - ts->tc.z1)); #if 0 printk("z1=%u z2=%u x=%u rt=%u\n", ts->tc.z1, ts->tc.z2, ts->tc.x, rt); #endif } return rt; } static s32 dejitter(s32 value, struct jitterbug *history, int histlen, bool first) { /* dejitter a single coordinate */ int i; s32 out; #define CONFIG_TSC2007_GTA04_DEJITTER_FIR_RESET /* dejitter algorithm based on new value and history of old values */ #if defined(CONFIG_TSC2007_GTA04_DEJITTER_NONE) out = value; /* no dejitter */ #elif defined(CONFIG_TSC2007_GTA04_DEJITTER_FIR) out = (value + history[0].val) / 2; /* average with previous input value (FIR filter) */ #elif defined(CONFIG_TSC2007_GTA04_DEJITTER_IIR) out = (value + history[0].out) / 2; /* average with previous output value (IIR filter) */ #elif defined(CONFIG_TSC2007_GTA04_DEJITTER_FIR_RESET) if(first) out = history[0].val = history[1].val = history[2].val = value; /* overwrite history */ else out = (8*value + 4*history[0].val + 3*history[1].val + 2*history[2].val + 1*history[3].val) / (8+4+3+2+1); #elif defined(CONFIG_TSC2007_GTA04_DEJITTER_NEW) /* more algorithms can be tested */ #endif /* update history */ for(i=histlen-1; i>0; i--) history[i]=history[i-1]; /* move */ history[0].val = value; history[0].out = out; return out; } static void tsc2007_dejitter(struct tsc2007 *ts, bool first) { /* dejitter all relevant channels */ ts->tc.x = dejitter(ts->tc.x, ts->jitterbufx, JITTER_HISTO, first); ts->tc.y = dejitter(ts->tc.y, ts->jitterbufy, JITTER_HISTO, first); /* dejitter pressure ? */ } static void tsc2007_shape_values(struct tsc2007 *ts) { /* Get the read values in the correct calibrated range. */ if(ts->swap_xy) { /* swap before applying the range limits */ u16 h = ts->tc.x; ts->tc.x = ts->tc.y; ts->tc.y = h; } /* X */ if(ts->tc.x > ts->max_x) ts->tc.x = ts->max_x; else if(ts->tc.x < ts->min_x) ts->tc.x = ts->min_x; if(ts->flip_x) ts->tc.x = (ts->max_x - ts->tc.x) + ts->min_x; /* Y */ if(ts->tc.y > ts->max_y) ts->tc.y = ts->max_y; else if(ts->tc.y < ts->min_y) ts->tc.y = ts->min_y; if(ts->flip_y) ts->tc.y = (ts->max_y - ts->tc.y) + ts->min_y; /* Z */ if(ts->pressure > ts->max_z) ts->pressure = ts->max_z; else if(ts->pressure < ts->min_z) ts->pressure = ts->min_z; } static void tsc2007_send_up_event(struct tsc2007 *ts) { struct input_dev *input = ts->input; dev_dbg(&ts->client->dev, "UP\n"); input_report_key(input, BTN_TOUCH, 0); input_report_abs(input, ABS_PRESSURE, 0); input_sync(input); ts->pressure = 0; } static void tsc2007_aux_work(struct work_struct *aux_work) { /* read TEMP0, TEMP1, AUX */ struct tsc2007 *ts = container_of(to_delayed_work(aux_work), struct tsc2007, aux_work); /* printk("tsc2007_aux_work\n"); */ tsc2007_read_temp(ts); /* Prepare for next touch reading - power down ADC, enable PENIRQ */ tsc2007_xfer(ts, PWRDOWN); schedule_delayed_work(&ts->aux_work, msecs_to_jiffies(TS_AUX_POLL_PERIOD)); /* printk("tsc2007_aux_work done\n"); */ } static void tsc2007_work(struct work_struct *work) { struct tsc2007 *ts = container_of(to_delayed_work(work), struct tsc2007, work); /* printk("tsc2007_work\n"); */ /* * 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 have rely on the pressure anyway. */ if (ts->get_pendown_state) { if (unlikely(!ts->get_pendown_state())) { tsc2007_send_up_event(ts); ts->pendown = false; goto out; } dev_dbg(&ts->client->dev, "pen is still down\n"); } tsc2007_read_values(ts); ts->pressure = tsc2007_calculate_pressure(ts); if (ts->pressure > 0) { struct input_dev *input = ts->input; if (!ts->pendown) { dev_dbg(&ts->client->dev, "DOWN\n"); input_report_key(input, BTN_TOUCH, 1); ts->pendown = true; tsc2007_dejitter(ts, true); } else { tsc2007_dejitter(ts, false); } tsc2007_shape_values(ts); input_report_abs(input, ABS_X, ts->tc.x); input_report_abs(input, ABS_Y, ts->tc.y); input_report_abs(input, ABS_PRESSURE, ts->pressure); input_sync(input); dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n", ts->tc.x, ts->tc.y, ts->pressure); } else if (!ts->get_pendown_state && ts->pendown) { /* * We don't have callback to check pendown state, so we * have to assume that since pressure reported is 0 the * pen was lifted up. */ tsc2007_send_up_event(ts); ts->pendown = false; } out: if (ts->pendown) schedule_delayed_work(&ts->work, msecs_to_jiffies(TS_POLL_PERIOD)); else { schedule_delayed_work(&ts->aux_work, msecs_to_jiffies(TS_AUX_POLL_PERIOD)); /* restart slow updates */ ts->aux_counter = 0; enable_irq(ts->irq); } /* printk("tsc2007_work done\n"); */ } static irqreturn_t tsc2007_irq(int irq, void *handle) { struct tsc2007 *ts = handle; /* printk("tsc2007_irq\n"); */ if (!ts->get_pendown_state || likely(ts->get_pendown_state())) { disable_irq_nosync(ts->irq); cancel_delayed_work(&ts->aux_work); schedule_delayed_work(&ts->work, msecs_to_jiffies(TS_POLL_DELAY)); } if (ts->clear_penirq) ts->clear_penirq(); return IRQ_HANDLED; } static void tsc2007_free_irq(struct tsc2007 *ts) { free_irq(ts->irq, ts); if (cancel_delayed_work_sync(&ts->work)) { /* * Work was pending, therefore we need to enable * IRQ here to balance the disable_irq() done in the * interrupt handler. */ enable_irq(ts->irq); } } static int tsc2007_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct tsc2007 *ts; struct tsc2007_platform_data *pdata = 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; /* Register sysfs hooks */ err = sysfs_create_group(&client->dev.kobj, &tsc2007_attr_group); if (err) { dev_err(&client->dev, "registering with sysfs failed!\n"); return err; } 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_DELAYED_WORK(&ts->work, tsc2007_work); INIT_DELAYED_WORK(&ts->aux_work, tsc2007_aux_work); ts->model = pdata->model; ts->x_plate_ohms = pdata->x_plate_ohms; ts->min_x = pdata->min_x ? : 0; ts->min_y = pdata->min_y ? : 0; ts->min_z = pdata->min_z ? : 0; ts->max_x = pdata->max_x ? : MAX_12BIT; ts->max_y = pdata->max_y ? : MAX_12BIT; ts->max_z = pdata->max_z ? : MAX_12BIT; ts->flip_x = pdata->flip_x; ts->flip_y = pdata->flip_y; ts->swap_xy = pdata->swap_xy; 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->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, pdata->min_x, pdata->max_x, pdata->fuzz_x, 0); input_set_abs_params(input_dev, ABS_Y, pdata->min_y, pdata->max_y, pdata->fuzz_y, 0); input_set_abs_params(input_dev, ABS_PRESSURE, pdata->min_z, pdata->max_z, pdata->fuzz_z, 0); if (pdata->init_platform_hw) pdata->init_platform_hw(); err = request_irq(ts->irq, tsc2007_irq, 0, client->dev.driver->name, ts); if (err < 0) { dev_err(&client->dev, "irq %d busy?\n", ts->irq); goto err_free_mem; } /* Prepare for touch readings - power down ADC and enable PENIRQ */ err = tsc2007_xfer(ts, PWRDOWN); if (err < 0) goto err_free_irq; err = input_register_device(input_dev); if (err) goto err_free_irq; i2c_set_clientdata(client, ts); /* schedule AUX and TEMP readings */ schedule_delayed_work(&ts->aux_work, msecs_to_jiffies(TS_AUX_POLL_PERIOD)); return 0; err_free_irq: tsc2007_free_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 tsc2007_remove(struct i2c_client *client) { struct tsc2007 *ts = i2c_get_clientdata(client); struct tsc2007_platform_data *pdata = client->dev.platform_data; tsc2007_free_irq(ts); if (pdata->exit_platform_hw) pdata->exit_platform_hw(); sysfs_remove_group(&client->dev.kobj, &tsc2007_attr_group); input_unregister_device(ts->input); kfree(ts); return 0; } static 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 = 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 "); MODULE_DESCRIPTION("TSC2007 TouchScreen Driver"); MODULE_LICENSE("GPL");