--- /dev/null
+/*
+ * 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");
Code Review / kvmfornfv.git / blobdiff