input: PCAP2 based touchscreen driver

Touchscreen driver for the PCAP2 multi function device used in
Motorola EZX smartphones.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 281 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 87a1ae63bcc4..ab02d72afbf3 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -510,4 +510,13 @@ config TOUCHSCREEN_W90X900
           To compile this driver as a module, choose M here: the
           module will be called w90p910_ts.
 
+config TOUCHSCREEN_PCAP
+        tristate "Motorola PCAP touchscreen"
+        depends on EZX_PCAP
+        help
+          Say Y here if you have a Motorola EZX telephone and
+          want to enable support for the built-in touchscreen.
+
+          To compile this driver as a module, choose M here: the
+          module will be called pcap_ts.
 endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 3e1c5e0b952f..4599bf7ad819 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -40,3 +40,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_ATMEL)	+= atmel-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)      += mainstone-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)       += zylonite-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_W90X900)       += w90p910_ts.o
+obj-$(CONFIG_TOUCHSCREEN_PCAP)          += pcap_ts.o
diff --git a/drivers/input/touchscreen/pcap_ts.c b/drivers/input/touchscreen/pcap_ts.c
new file mode 100644
index 000000000000..67fcd33595de
--- /dev/null
+++ b/drivers/input/touchscreen/pcap_ts.c
@@ -0,0 +1,271 @@
+/*
+ * Driver for Motorola PCAP2 touchscreen as found in the EZX phone platform.
+ *
+ *  Copyright (C) 2006 Harald Welte <laforge@openezx.org>
+ *  Copyright (C) 2009 Daniel Ribeiro <drwyrm@gmail.com>
+ *
+ *  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/init.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/pm.h>
+#include <linux/timer.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/mfd/ezx-pcap.h>
+
+struct pcap_ts {
+        struct pcap_chip *pcap;
+        struct input_dev *input;
+        struct delayed_work work;
+        u16 x, y;
+        u16 pressure;
+        u8 read_state;
+};
+
+#define SAMPLE_DELAY    20 /* msecs */
+
+#define X_AXIS_MIN      0
+#define X_AXIS_MAX      1023
+#define Y_AXIS_MAX      X_AXIS_MAX
+#define Y_AXIS_MIN      X_AXIS_MIN
+#define PRESSURE_MAX    X_AXIS_MAX
+#define PRESSURE_MIN    X_AXIS_MIN
+
+static void pcap_ts_read_xy(void *data, u16 res[2])
+{
+        struct pcap_ts *pcap_ts = data;
+
+        switch (pcap_ts->read_state) {
+        case PCAP_ADC_TS_M_PRESSURE:
+                /* pressure reading is unreliable */
+                if (res[0] > PRESSURE_MIN && res[0] < PRESSURE_MAX)
+                        pcap_ts->pressure = res[0];
+                pcap_ts->read_state = PCAP_ADC_TS_M_XY;
+                schedule_delayed_work(&pcap_ts->work, 0);
+                break;
+        case PCAP_ADC_TS_M_XY:
+                pcap_ts->y = res[0];
+                pcap_ts->x = res[1];
+                if (pcap_ts->x <= X_AXIS_MIN || pcap_ts->x >= X_AXIS_MAX ||
+                    pcap_ts->y <= Y_AXIS_MIN || pcap_ts->y >= Y_AXIS_MAX) {
+                        /* pen has been released */
+                        input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
+                        input_report_key(pcap_ts->input, BTN_TOUCH, 0);
+
+                        pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
+                        schedule_delayed_work(&pcap_ts->work, 0);
+                } else {
+                        /* pen is touching the screen */
+                        input_report_abs(pcap_ts->input, ABS_X, pcap_ts->x);
+                        input_report_abs(pcap_ts->input, ABS_Y, pcap_ts->y);
+                        input_report_key(pcap_ts->input, BTN_TOUCH, 1);
+                        input_report_abs(pcap_ts->input, ABS_PRESSURE,
+                                                pcap_ts->pressure);
+
+                        /* switch back to pressure read mode */
+                        pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
+                        schedule_delayed_work(&pcap_ts->work,
+                                        msecs_to_jiffies(SAMPLE_DELAY));
+                }
+                input_sync(pcap_ts->input);
+                break;
+        default:
+                dev_warn(&pcap_ts->input->dev,
+                                "pcap_ts: Warning, unhandled read_state %d\n",
+                                pcap_ts->read_state);
+                break;
+        }
+}
+
+static void pcap_ts_work(struct work_struct *work)
+{
+        struct delayed_work *dw = container_of(work, struct delayed_work, work);
+        struct pcap_ts *pcap_ts = container_of(dw, struct pcap_ts, work);
+        u8 ch[2];
+
+        pcap_set_ts_bits(pcap_ts->pcap,
+                        pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
+
+        if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY)
+                return;
+
+        /* start adc conversion */
+        ch[0] = PCAP_ADC_CH_TS_X1;
+        ch[1] = PCAP_ADC_CH_TS_Y1;
+        pcap_adc_async(pcap_ts->pcap, PCAP_ADC_BANK_1, 0, ch,
+                                                pcap_ts_read_xy, pcap_ts);
+}
+
+static irqreturn_t pcap_ts_event_touch(int pirq, void *data)
+{
+        struct pcap_ts *pcap_ts = data;
+
+        if (pcap_ts->read_state == PCAP_ADC_TS_M_STANDBY) {
+                pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
+                schedule_delayed_work(&pcap_ts->work, 0);
+        }
+        return IRQ_HANDLED;
+}
+
+static int pcap_ts_open(struct input_dev *dev)
+{
+        struct pcap_ts *pcap_ts = input_get_drvdata(dev);
+
+        pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
+        schedule_delayed_work(&pcap_ts->work, 0);
+
+        return 0;
+}
+
+static void pcap_ts_close(struct input_dev *dev)
+{
+        struct pcap_ts *pcap_ts = input_get_drvdata(dev);
+
+        cancel_delayed_work_sync(&pcap_ts->work);
+
+        pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
+        pcap_set_ts_bits(pcap_ts->pcap,
+                                pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
+}
+
+static int __devinit pcap_ts_probe(struct platform_device *pdev)
+{
+        struct input_dev *input_dev;
+        struct pcap_ts *pcap_ts;
+        int err = -ENOMEM;
+
+        pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
+        if (!pcap_ts)
+                return err;
+
+        pcap_ts->pcap = dev_get_drvdata(pdev->dev.parent);
+        platform_set_drvdata(pdev, pcap_ts);
+
+        input_dev = input_allocate_device();
+        if (!input_dev)
+                goto fail;
+
+        INIT_DELAYED_WORK(&pcap_ts->work, pcap_ts_work);
+
+        pcap_ts->read_state = PCAP_ADC_TS_M_NONTS;
+        pcap_set_ts_bits(pcap_ts->pcap,
+                                pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
+
+        pcap_ts->input = input_dev;
+        input_set_drvdata(input_dev, pcap_ts);
+
+        input_dev->name = "pcap-touchscreen";
+        input_dev->phys = "pcap_ts/input0";
+        input_dev->id.bustype = BUS_HOST;
+        input_dev->id.vendor = 0x0001;
+        input_dev->id.product = 0x0002;
+        input_dev->id.version = 0x0100;
+        input_dev->dev.parent = &pdev->dev;
+        input_dev->open = pcap_ts_open;
+        input_dev->close = pcap_ts_close;
+
+        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, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
+        input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
+        input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN,
+                             PRESSURE_MAX, 0, 0);
+
+        err = input_register_device(pcap_ts->input);
+        if (err)
+                goto fail_allocate;
+
+        err = request_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS),
+                        pcap_ts_event_touch, 0, "Touch Screen", pcap_ts);
+        if (err)
+                goto fail_register;
+
+        return 0;
+
+fail_register:
+        input_unregister_device(input_dev);
+        goto fail;
+fail_allocate:
+        input_free_device(input_dev);
+fail:
+        kfree(pcap_ts);
+
+        return err;
+}
+
+static int __devexit pcap_ts_remove(struct platform_device *pdev)
+{
+        struct pcap_ts *pcap_ts = platform_get_drvdata(pdev);
+
+        free_irq(pcap_to_irq(pcap_ts->pcap, PCAP_IRQ_TS), pcap_ts);
+        cancel_delayed_work_sync(&pcap_ts->work);
+
+        input_unregister_device(pcap_ts->input);
+
+        kfree(pcap_ts);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int pcap_ts_suspend(struct device *dev)
+{
+        struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
+
+        pcap_set_ts_bits(pcap_ts->pcap, PCAP_ADC_TS_REF_LOWPWR);
+        return 0;
+}
+
+static int pcap_ts_resume(struct device *dev)
+{
+        struct pcap_ts *pcap_ts = dev_get_drvdata(dev);
+
+        pcap_set_ts_bits(pcap_ts->pcap,
+                                pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT);
+        return 0;
+}
+
+static struct dev_pm_ops pcap_ts_pm_ops = {
+        .suspend        = pcap_ts_suspend,
+        .resume         = pcap_ts_resume,
+};
+#define PCAP_TS_PM_OPS (&pcap_ts_pm_ops)
+#else
+#define PCAP_TS_PM_OPS NULL
+#endif
+
+static struct platform_driver pcap_ts_driver = {
+        .probe          = pcap_ts_probe,
+        .remove         = __devexit_p(pcap_ts_remove),
+        .driver         = {
+                .name   = "pcap-ts",
+                .owner  = THIS_MODULE,
+                .pm     = PCAP_TS_PM_OPS,
+        },
+};
+
+static int __init pcap_ts_init(void)
+{
+        return platform_driver_register(&pcap_ts_driver);
+}
+
+static void __exit pcap_ts_exit(void)
+{
+        platform_driver_unregister(&pcap_ts_driver);
+}
+
+module_init(pcap_ts_init);
+module_exit(pcap_ts_exit);
+
+MODULE_DESCRIPTION("Motorola PCAP2 touchscreen driver");
+MODULE_AUTHOR("Daniel Ribeiro / Harald Welte");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:pcap_ts");