/* * 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> #include <linux/of_device.h> #include <linux/of.h> #include <linux/of_gpio.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_period; /* in jiffies */ int fuzzx; int fuzzy; int fuzzz; unsigned gpio; int irq; wait_queue_head_t wait; bool stopped; int (*get_pendown_state)(struct device *); 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(&ts->client->dev); } 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 && !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, 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 (tsc2007_is_pen_down(ts)) 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); } #ifdef CONFIG_OF static int tsc2007_get_pendown_state_gpio(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct tsc2007 *ts = i2c_get_clientdata(client); return !gpio_get_value(ts->gpio); } static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts) { struct device_node *np = client->dev.of_node; u32 val32; u64 val64; if (!np) { dev_err(&client->dev, "missing device tree data\n"); return -EINVAL; } if (!of_property_read_u32(np, "ti,max-rt", &val32)) ts->max_rt = val32; else ts->max_rt = MAX_12BIT; if (!of_property_read_u32(np, "ti,fuzzx", &val32)) ts->fuzzx = val32; if (!of_property_read_u32(np, "ti,fuzzy", &val32)) ts->fuzzy = val32; if (!of_property_read_u32(np, "ti,fuzzz", &val32)) ts->fuzzz = val32; if (!of_property_read_u64(np, "ti,poll-period", &val64)) ts->poll_period = msecs_to_jiffies(val64); else ts->poll_period = msecs_to_jiffies(1); if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) { ts->x_plate_ohms = val32; } else { dev_err(&client->dev, "missing ti,x-plate-ohms devicetree property."); return -EINVAL; } ts->gpio = of_get_gpio(np, 0); if (gpio_is_valid(ts->gpio)) ts->get_pendown_state = tsc2007_get_pendown_state_gpio; else dev_warn(&client->dev, "GPIO not specified in DT (of_get_gpio returned %d)\n", ts->gpio); return 0; } #else static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts) { dev_err(&client->dev, "platform data is required!\n"); return -EINVAL; } #endif static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts, const struct tsc2007_platform_data *pdata, const struct i2c_device_id *id) { ts->model = pdata->model; ts->x_plate_ohms = pdata->x_plate_ohms; ts->max_rt = pdata->max_rt ? : MAX_12BIT; ts->poll_period = msecs_to_jiffies(pdata->poll_period ? : 1); ts->get_pendown_state = pdata->get_pendown_state; ts->clear_penirq = pdata->clear_penirq; ts->fuzzx = pdata->fuzzx; ts->fuzzy = pdata->fuzzy; ts->fuzzz = pdata->fuzzz; if (pdata->x_plate_ohms == 0) { dev_err(&client->dev, "x_plate_ohms is not set up in platform data"); return -EINVAL; } return 0; } static void tsc2007_call_exit_platform_hw(void *data) { struct device *dev = data; const struct tsc2007_platform_data *pdata = dev_get_platdata(dev); pdata->exit_platform_hw(); } static int tsc2007_probe(struct i2c_client *client, const struct i2c_device_id *id) { const struct tsc2007_platform_data *pdata = dev_get_platdata(&client->dev); struct tsc2007 *ts; struct input_dev *input_dev; int err; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) return -EIO; ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL); if (!ts) return -ENOMEM; if (pdata) err = tsc2007_probe_pdev(client, ts, pdata, id); else err = tsc2007_probe_dt(client, ts); if (err) return err; input_dev = devm_input_allocate_device(&client->dev); if (!input_dev) return -ENOMEM; i2c_set_clientdata(client, ts); ts->client = client; ts->irq = client->irq; ts->input = input_dev; init_waitqueue_head(&ts->wait); 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, ts->fuzzx, 0); input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0); input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, ts->fuzzz, 0); if (pdata) { if (pdata->exit_platform_hw) { err = devm_add_action(&client->dev, tsc2007_call_exit_platform_hw, &client->dev); if (err) { dev_err(&client->dev, "Failed to register exit_platform_hw action, %d\n", err); return err; } } if (pdata->init_platform_hw) pdata->init_platform_hw(); } err = devm_request_threaded_irq(&client->dev, ts->irq, tsc2007_hard_irq, tsc2007_soft_irq, IRQF_ONESHOT, client->dev.driver->name, ts); if (err) { dev_err(&client->dev, "Failed to request irq %d: %d\n", ts->irq, err); return err; } tsc2007_stop(ts); err = input_register_device(input_dev); if (err) { dev_err(&client->dev, "Failed to register input device: %d\n", err); return err; } return 0; } static const struct i2c_device_id tsc2007_idtable[] = { { "tsc2007", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, tsc2007_idtable); #ifdef CONFIG_OF static const struct of_device_id tsc2007_of_match[] = { { .compatible = "ti,tsc2007" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, tsc2007_of_match); #endif static struct i2c_driver tsc2007_driver = { .driver = { .owner = THIS_MODULE, .name = "tsc2007", .of_match_table = of_match_ptr(tsc2007_of_match), }, .id_table = tsc2007_idtable, .probe = tsc2007_probe, }; module_i2c_driver(tsc2007_driver); MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>"); MODULE_DESCRIPTION("TSC2007 TouchScreen Driver"); MODULE_LICENSE("GPL");