[patch 08/14] input: PCAP2 based touchscreen driver

From: stefan
Date: Fri Nov 21 2008 - 11:50:19 EST


Touchscreen driver based on the PCAP2 multi function device.

Signed-off-by: Daniel Ribeiro <drwyrm@xxxxxxxxx>

---
drivers/input/touchscreen/Kconfig | 9 ++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/pcap_ts.c | 258 +++++++++++++++++++++++++++++++++++
3 files changed, 268 insertions(+), 0 deletions(-)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 3d1ab8f..a1bd364 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -376,4 +376,13 @@ config TOUCHSCREEN_TOUCHIT213
To compile this driver as a module, choose M here: the
module will be called touchit213.

+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 support the built-in touchscreen.
+
+ If unsure, say N.
+
endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 15cf290..97d8931 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -31,3 +31,4 @@ wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9705) += wm9705.o
wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9712) += wm9712.o
wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9713) += wm9713.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE) += mainstone-wm97xx.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 0000000..ea18aff
--- /dev/null
+++ b/drivers/input/touchscreen/pcap_ts.c
@@ -0,0 +1,258 @@
+/*
+ * pcap_ts.c - Touchscreen driver for Motorola PCAP2 based touchscreen as found
+ * in the EZX phone platform.
+ *
+ * Copyright (C) 2006 Harald Welte <laforge@xxxxxxxxxxx>
+ * Copyright (C) 2007-2008 Daniel Ribeiro <drwyrm@xxxxxxxxx>
+ *
+ * Based on information found in the original Motorola 2.4.x ezx-ts.c driver.
+ *
+ * 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 input_dev *input;
+ struct timer_list timer;
+ struct work_struct work;
+ u16 x, y;
+ u16 pressure;
+ u8 read_state;
+};
+
+struct pcap_ts *pcap_ts;
+
+#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
+
+/* if we try to read faster, pressure reading becomes unreliable */
+#define SAMPLE_INTERVAL (HZ/50)
+
+static void pcap_ts_read_xy(void)
+{
+ u32 res[2];
+
+ ezx_pcap_get_adc_channel_result(PCAP_ADC_CH_TS_X1, PCAP_ADC_CH_TS_Y1,
+ res);
+ ezx_pcap_disable_adc();
+
+ switch (pcap_ts->read_state) {
+ case PCAP_ADC_TS_M_PRESSURE:
+ /* save pressure, start xy read */
+ pcap_ts->pressure = res[0];
+ pcap_ts->read_state = PCAP_ADC_TS_M_XY;
+ schedule_work(&pcap_ts->work);
+ 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 ||
+ pcap_ts->pressure <= PRESSURE_MIN ||
+ pcap_ts->pressure >= PRESSURE_MAX) {
+ /* pen has been released */
+ input_report_key(pcap_ts->input, BTN_TOUCH, 0);
+ input_report_abs(pcap_ts->input, ABS_PRESSURE, 0);
+
+ /* no need for timer, we'll get interrupted with
+ * next touch down event */
+ del_timer(&pcap_ts->timer);
+
+ /* ask PCAP2 to interrupt us if touch event happens
+ * again */
+ pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
+ ezx_pcap_unmask_event(PCAP_IRQ_TS);
+ schedule_work(&pcap_ts->work);
+ } 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;
+ mod_timer(&pcap_ts->timer,
+ jiffies + SAMPLE_INTERVAL);
+ }
+ input_sync(pcap_ts->input);
+ break;
+ default:
+ break;
+ }
+}
+
+static void pcap_ts_work(struct work_struct *unused)
+{
+ u32 tmp;
+
+ switch (pcap_ts->read_state) {
+ case PCAP_ADC_TS_M_STANDBY:
+ /* set TS to standby */
+ ezx_pcap_read(PCAP_REG_ADC, &tmp);
+ tmp &= ~PCAP_ADC_TS_M_MASK;
+ tmp |= (PCAP_ADC_TS_M_STANDBY << PCAP_ADC_TS_M_SHIFT);
+ ezx_pcap_write(PCAP_REG_ADC, tmp);
+ break;
+ case PCAP_ADC_TS_M_PRESSURE:
+ case PCAP_ADC_TS_M_XY:
+ /* start adc conversion */
+ ezx_pcap_start_adc(PCAP_ADC_BANK_1, PCAP_ADC_T_NOW,
+ (pcap_ts->read_state << PCAP_ADC_TS_M_SHIFT),
+ pcap_ts_read_xy, NULL);
+ break;
+ }
+}
+
+static void pcap_ts_event_touch(u32 events)
+{
+ /* pen touch down, mask touch event and start reading pressure */
+ ezx_pcap_mask_event(PCAP_IRQ_TS);
+ pcap_ts->read_state = PCAP_ADC_TS_M_PRESSURE;
+ schedule_work(&pcap_ts->work);
+}
+
+static void pcap_ts_timer_fn(unsigned long data)
+{
+ schedule_work(&pcap_ts->work);
+}
+
+static int __devinit pcap_ts_probe(struct platform_device *pdev)
+{
+ struct input_dev *input_dev;
+ int err = -ENOMEM;
+
+ pcap_ts = kzalloc(sizeof(*pcap_ts), GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!pcap_ts || !input_dev)
+ goto fail;
+
+ INIT_WORK(&pcap_ts->work, pcap_ts_work);
+
+ pcap_ts->read_state = PCAP_ADC_TS_M_STANDBY;
+
+ init_timer(&pcap_ts->timer);
+ pcap_ts->timer.data = (unsigned long) pcap_ts;
+ pcap_ts->timer.function = &pcap_ts_timer_fn;
+
+ pcap_ts->input = input_dev;
+
+ 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->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);
+
+ ezx_pcap_register_event(PCAP_IRQ_TS, pcap_ts_event_touch,
+ "Touch Screen");
+
+ err = input_register_device(pcap_ts->input);
+ if (err)
+ goto fail_touch;
+
+ schedule_work(&pcap_ts->work);
+
+ return 0;
+
+fail_touch:
+ ezx_pcap_unregister_event(PCAP_IRQ_TS);
+fail:
+ input_free_device(input_dev);
+ kfree(pcap_ts);
+
+ return err;
+}
+
+static int __devexit pcap_ts_remove(struct platform_device *pdev)
+{
+ ezx_pcap_unregister_event(PCAP_IRQ_TS);
+
+ del_timer_sync(&pcap_ts->timer);
+
+ input_unregister_device(pcap_ts->input);
+ kfree(pcap_ts);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int pcap_ts_suspend(struct platform_device *dev, pm_message_t state)
+{
+ u32 tmp;
+ ezx_pcap_read(PCAP_REG_ADC, &tmp);
+ tmp |= PCAP_ADC_TS_REF_LOWPWR;
+ ezx_pcap_write(PCAP_REG_ADC, tmp);
+ return 0;
+}
+
+static int pcap_ts_resume(struct platform_device *dev)
+{
+ u32 tmp;
+ ezx_pcap_read(PCAP_REG_ADC, &tmp);
+ tmp &= ~PCAP_ADC_TS_REF_LOWPWR;
+ ezx_pcap_write(PCAP_REG_ADC, tmp);
+ return 0;
+}
+#else
+
+#define pcap_ts_suspend NULL
+#define pcap_ts_resume NULL
+
+#endif
+
+static struct platform_driver pcap_ts_driver = {
+ .probe = pcap_ts_probe,
+ .remove = __devexit_p(pcap_ts_remove),
+ .suspend = pcap_ts_suspend,
+ .resume = pcap_ts_resume,
+ .driver = {
+ .name = "pcap-ts",
+ .owner = THIS_MODULE,
+ },
+};
+
+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");
--
tg: (fc25aca..) ezx/pcap_ts (depends on: ezx/local/pcap)

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