Hi all,
Here's an updated version of the Texas Instruments TSC2008 driver. Many
thanks to Dmitry Torokhov for providing feedback!
This code successfully compiles both as built-in and as a module. If
anyone has a hardware platform that can be used for testing, I welcome
any feedback. Our hardware should arrive in early July, so I'll update
(v0.3?) based on testing after that.
Thanks,
Chris
linux-2.6.29.3-tsc2008-v0.2patch:
-------------------------------------------------------------------
Signed-off-by: Chris Verges <chrisv@xxxxxxxxxxxxxxxxxx>
Index: include/linux/spi/tsc2008.h
===================================================================
--- linux-2.6.29.3-orig/include/linux/spi/tsc2008.h (revision 0)
+++ linux-2.6.29.3/include/linux/spi/tsc2008.h (revision 32)
@@ -0,0 +1,22 @@
+#ifndef __LINUX_SPI_TSC2008_H
+#define __LINUX_SPI_TSC2008_H
+
+/* linux/spi/tsc2008.h */
+
+#define TSC2008_ADC_8BITS (0x01)
+#define TSC2008_ADC_12BITS (0x02)
+
+struct tsc2008_platform_data {
+ u16 model; /* 2008. */
+ u16 x_plate_ohms;
+ u16 adc_bits; /* TSC2008_ADC_12BITS
(default)
+ or TSC2008_ADC_8BITS
*/
+ u16 irq; /* GPIO to be used for
IRQ */
+
+ u8 pull_up; /* 50 (default) or 90
ohms */
+ u8 mav; /* 0 (enable) or 1
(bypass) */
+
+ int (*get_pendown_state)(void);
+};
+
+#endif
Index: drivers/input/touchscreen/Kconfig
===================================================================
--- linux-2.6.29.3-orig/drivers/input/touchscreen/Kconfig
(revision 11)
+++ linux-2.6.29.3/drivers/input/touchscreen/Kconfig (revision 32)
@@ -408,4 +408,17 @@
To compile this driver as a module, choose M here: the
module will be called tsc2007.
+config TOUCHSCREEN_TSC2008
+ tristate "TSC2008 based touchscreens"
+ depends on SPI_MASTER
+ help
+ Say Y here if you have a touchscreen interface using the
+ TSC2008 controller, and your board-specific setup code
+ includes that in its table of SPI devices.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called tsc2008.
+
endif
Index: drivers/input/touchscreen/tsc2008.c
===================================================================
--- linux-2.6.29.3-orig/drivers/input/touchscreen/tsc2008.c
(revision 0)
+++ linux-2.6.29.3/drivers/input/touchscreen/tsc2008.c (revision 32)
@@ -0,0 +1,559 @@
+/*
+ * drivers/input/touchscreen/tsc2008.c
+ *
+ * Copyright (c) 2009 Cyber Switching, Inc.
+ * Chris Verges <chrisv@xxxxxxxxxxxxxxxxxx>
+ *
+ * Using code from:
+ * - tsc2008_core.c, tsc2008.h, tsc2008_platform.c
+ * Copyright (c) 2008 MindTree Limited
+ * - tsc2007.c
+ * Copyright (c) 2008 MtekVision Co., Ltd.
+ * - 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/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/tsc2008.h>
+
+
+#define DRV_VERSION "0.2"
+
+#define TS_POLL_DELAY (10 * 1000) /* ns delay before the first
sample */
+#define TS_POLL_PERIOD (5 * 1000) /* ns delay between samples */
+
+#define TSC2008_MEASURE_Y (0x1 << 4)
+#define TSC2008_SETUP (0x2 << 4)
+#define TSC2008_MEASURE_Z1 (0x3 << 4)
+#define TSC2008_MEASURE_Z2 (0x4 << 4)
+#define TSC2008_MEASURE_X (0x5 << 4)
+#define TSC2008_MEASURE_AUX (0x6 << 4)
+#define TSC2008_MEASURE_TEMP2 (0x7 << 4)
+#define TSC2008_START (0x8 << 4)
+
+#define TSC2008_12BIT (0x0 << 3)
+#define TSC2008_8BIT (0x1 << 3)
+
+#define TSC2008_REF_DIFF (0x0 << 2)
+#define TSC2008_REF_SINGLE (0x1 << 2)
+
+#define TSC2008_POWER_OFF_IRQ_EN (0x0 << 0)
+#define TSC2008_ADC_ON_IRQ_DIS0 (0x1 << 0)
+#define TSC2008_ADC_OFF_IRQ_EN (0x2 << 0)
+#define TSC2008_ADC_ON_IRQ_DIS1 (0x3 << 0)
+
+#define TSC2008_RESET (0x1)
+
+#define TSC2008_PENIRQ_50_OHM (0x0 << 3)
+#define TSC2008_PENIRQ_90_OHM (0x1 << 3)
+
+#define TSC2008_MAV_ENABLE (0x0 << 2)
+#define TSC2008_MAV_BYPASS (0x1 << 2)
+
+#define TSC2008_SOFTWARE_RESET \
+ (TSC2008_START | TSC2008_SETUP | TSC2008_RESET)
+
+static struct spi_driver tsc2008_driver;
+
+struct ts_event {
+ u16 x;
+ u16 y;
+ u16 z1, z2;
+};
+
+struct tsc2008 {
+ struct input_dev *input;
+ char phys[32];
+
+ struct spi_device *spi;
+
+ u16 model;
+ u16 x_plate_ohms;
+ u8 adc_bits;
+ int irq;
+
+ spinlock_t lock; /* protects timer, msg,
*/
+ /* xfer, and msg_idx
*/
+ unsigned pendown;
+ struct ts_event tc;
+
+ struct timer_list timer;
+ struct spi_message msg[6];
+ struct spi_transfer xfer[12];
+
+ u8 read_x;
+ u8 read_y;
+ u8 read_z1;
+ u8 read_z2;
+
+ u16 x_pos;
+ u16 y_pos;
+ u16 z1_val;
+ u16 z2_val;
+
+ u8 msg_idx;
+
+ int (*get_pendown_state)(void);
+};
+
+static void tsc2008_report(void *data)
+{
+ struct tsc2008 *ts = (struct tsc2008 *)data;
+ struct input_dev *input = ts->input;
+ u16 tmp;
+ u16 pressure;
+
+ /* The X and Y coordinates read from the TSC2008 need to be
swapped
+ * to work with the X window system.
+ */
+ switch (ts->adc_bits) {
+ case TSC2008_ADC_12BITS:
+ /* TSC2008 transfers in big endian format (MSB to LSB)
as a
+ * 12-bit number. Need to convert endianness and
truncate.
+ */
+ tmp = ts->x_pos;
+ ts->x_pos = ((be16_to_cpu(ts->y_pos) << 1) >> 4) &
0x0FFF;
+ ts->y_pos = ((be16_to_cpu(tmp) << 1) >> 4) &
0x0FFF;
+ ts->z1_val = ((be16_to_cpu(ts->z1_val) << 1) >> 4) &
0x0FFF;
+ ts->z2_val = ((be16_to_cpu(ts->z2_val) << 1) >> 4) &
0x0FFF;
+ break;
+ case TSC2008_ADC_8BITS:
+ tmp = ts->x_pos;
+ ts->x_pos = (ts->y_pos << 1) & 0x00FF;
+ ts->y_pos = (tmp << 1) & 0x00FF;
+ ts->z1_val = (ts->z1_val << 1) & 0x00FF;
+ ts->z2_val = (ts->z2_val << 1) & 0x00FF;
+ break;
+ }
+
+ /* Calculate the pressure according to Equation #1 on page 12
+ * of the TSC2008 datasheet.
+ */
+ pressure = ts->z2_val / ts->z1_val;
+ pressure -= 1;
+ pressure *= ts->y_pos;
+ pressure *= ts->x_plate_ohms;
+ pressure /= 4096;
+
+ /* Report the values to the input subsystem */
+ input_report_abs(input, ABS_X, ts->x_pos);
+ input_report_abs(input, ABS_Y, ts->y_pos);
+ input_report_abs(input, ABS_PRESSURE, pressure);
+ input_report_abs(input, BTN_TOUCH, 1);
+
+ /* Reset the SPI message queue */
+ ts->msg_idx = 0;
+
+ /* Check for prolonged touches (i.e. drags and drawings) */
+ if (ts->get_pendown_state())
+ mod_timer(&ts->timer, jiffies + 2);
+ else {
+ input_report_abs(input, ABS_PRESSURE, 0);
+ input_report_abs(input, BTN_TOUCH, 0);
+ input_sync(input);
+ enable_irq(ts->irq);
+ }
+}
+
+static void tsc2008_spi_again_submit(void *data)
+{
+ struct tsc2008 *ts = data;
+ struct spi_message *m;
+ struct spi_transfer *t;
+
+ spin_lock_irqsave(&ts->lock);
+
+ m = &ts->msg[ts->msg_idx];
+ t = list_entry(m->transfers.prev, struct spi_transfer,
transfer_list);
+ ts->msg_idx++;
+
+ m = &ts->msg[ts->msg_idx];
+ spi_async(ts->spi, m);
+
+ spin_unlock_irqrestore(&ts->lock);
+}
+
+static void tsc2008_timer(unsigned long arg)
+{
+ struct tsc2008 *ts = (struct tsc2008 *)arg;
+ int stat;
+
+ spin_lock_irqsave(&ts->lock);
+
+ if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
+ struct input_dev *input = ts->input;
+
+ dev_dbg(&ts->spi->dev, "pen is up\n");
+
+ input_report_key(input, BTN_TOUCH, 0);
+ input_report_abs(input, ABS_PRESSURE, 0);
+ input_sync(input);
+
+ ts->pendown = 0;
+ enable_irq(ts->irq);
+ } else {
+ /* pen is still down, continue with the measurement */
+ dev_dbg(&ts->spi->dev, "pen is still down\n");
+
+ ts->msg_idx = 0;
+ stat = spi_async(ts->spi, &ts->msg[0]);
+ if (stat)
+ dev_err(&ts->spi->dev, "spi_async----> %d\n",
stat);
+ }
+
+ spin_unlock_irqrestore(&ts->lock);
+}
+
+static irqreturn_t tsc2008_handle_penirq(int irq, void *handle)
+{
+ struct tsc2008 *ts = handle;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ts->lock, flags);
+
+ if (likely(ts->get_pendown_state())) {
+ disable_irq(ts->irq);
+ mod_timer(&ts->timer, jiffies + 3);
+ }
+
+ spin_unlock_irqrestore(&ts->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static void tsc2008_spi_setup(struct tsc2008 *ts)
+{
+ struct spi_message *m;
+ struct spi_transfer *t;
+ u16 rx_len;
+ u16 tx_delay;
+
+ switch (ts->adc_bits) {
+ case TSC2008_ADC_8BITS:
+ tx_delay = 50;
+ rx_len = 1;
+ break;
+ case TSC2008_ADC_12BITS:
+ default:
+ tx_delay = 100;
+ rx_len = 2;
+ break;
+ }
+
+ /* Setup the SPI message for reading X */
+ {
+ m = &ts->msg[0];
+ t = &ts->xfer[0];
+
+ /* Transmit the command */
+ spi_message_init(m);
+ memset(t, 0, sizeof(*t));
+ t->tx_buf = &ts->read_x;
+ t->len = 1;
+ t->delay_usecs = tx_delay;
+ spi_message_add_tail(t, m);
+
+ /* Receive the results */
+ t++;
+ memset(t, 0, sizeof(*t));
+ t->rx_buf = &ts->x_pos;
+ t->len = rx_len;
+ spi_message_add_tail(t, m);
+
+ m->complete = tsc2008_spi_again_submit;
+ m->context = ts;
+ }
+
+ /* Setup the SPI message for reading Y */
+ {
+ m++;
+ t++;
+
+ /* Transmit the command */
+ spi_message_init(m);
+ memset(t, 0, sizeof(*t));
+ t->tx_buf = &ts->read_y;
+ t->len = 1;
+ t->delay_usecs = tx_delay;
+ spi_message_add_tail(t, m);
+
+ /* Receive the results */
+ t++;
+ memset(t, 0, sizeof(*t));
+ t->rx_buf = &ts->y_pos;
+ t->len = rx_len;
+ spi_message_add_tail(t, m);
+
+ m->complete = tsc2008_spi_again_submit;
+ m->context = ts;
+ }
+
+ /* Setup the SPI message for reading Z1 */
+ {
+ m++;
+ t++;
+
+ /* Transmit the command */
+ spi_message_init(m);
+ memset(t, 0, sizeof(*t));
+ t->tx_buf = &ts->read_z1;
+ t->len = 1;
+ t->delay_usecs = tx_delay;
+ spi_message_add_tail(t, m);
+
+ /* Receive the results */
+ t++;
+ memset(t, 0, sizeof(*t));
+ t->rx_buf = &ts->z1_val;
+ t->len = rx_len;
+ spi_message_add_tail(t, m);
+
+ m->complete = tsc2008_spi_again_submit;
+ m->context = ts;
+ }
+
+ /* Setup the SPI message for reading Z2 */
+ {
+ m++;
+ t++;
+
+ /* Transmit the command */
+ spi_message_init(m);
+ memset(t, 0, sizeof(*t));
+ t->tx_buf = &ts->read_z2;
+ t->len = 1;
+ t->delay_usecs = tx_delay;
+ spi_message_add_tail(t, m);
+
+ /* Receive the results */
+ t++;
+ memset(t, 0, sizeof(*t));
+ t->rx_buf = &ts->z2_val;
+ t->len = rx_len;
+ spi_message_add_tail(t, m);
+
+ m->complete = tsc2008_report;
+ m->context = ts;
+ }
+}
+
+static int __devinit tsc2008_probe(struct spi_device *spi)
+{
+ struct tsc2008 *ts;
+ struct tsc2008_platform_data *pdata;
+ struct input_dev *input;
+ int err;
+ u8 tx_buf;
+
+ pdata = spi->dev.platform_data;
+ if (!pdata) {
+ dev_err(&spi->dev, "no platform data?!\n");
+ return -ENODEV;
+ }
+
+ /* don't exceed the max specified sample rate */
+ if (spi->max_speed_hz > 25000000) {
+ dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
+ (spi->max_speed_hz / 1000));
+ return -EINVAL;
+ }
+
+ /* While the TSC2008 may like 12-bit words, most SPI controller
+ * drivers may not. Stick with something portable.
+ */
+ spi->bits_per_word = 8;
+ spi->mode = SPI_MODE_0;
+ err = spi_setup(spi);
+ if (err < 0)
+ return err;
+
+ /* Allocate the memory required for this driver */
+ ts = kzalloc(sizeof(*ts), GFP_KERNEL);
+ input = input_allocate_device();
+ if (!ts || !input) {
+ err = -ENOMEM;
+ goto err_free_mem;
+ }
+
+ /* Initialize the TSC2008 driver data structure */
+ dev_set_drvdata(&spi->dev, ts);
+
+ init_timer(&ts->timer);
+ spin_lock_init(&ts->lock);
+
+ ts->spi = spi;
+ ts->input = input;
+ ts->timer.function = tsc2008_timer;
+ ts->timer.data = (unsigned long)ts;
+ ts->model = pdata->model ? : 2008;
+ ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
+ ts->adc_bits = pdata->adc_bits ? :
TSC2008_ADC_12BITS;
+ ts->irq = pdata->irq;
+ ts->get_pendown_state = pdata->get_pendown_state;
+
+ snprintf(ts->phys, sizeof(ts->phys),
+ "%s/input0", dev_name(&spi->dev));
+
+ /* Initialize the input driver */
+ input->name = "TSC2008 TouchScreen";
+ input->phys = ts->phys;
+ input->dev.parent = &spi->dev;
+ input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+ /* Set the resolution mode that will be used -- 8 bits or 12
bits */
+ switch (ts->adc_bits) {
+ default:
+ /* If nothing valid is specified, assume 12 bits */
+ ts->adc_bits = TSC2008_ADC_12BITS;
+ case TSC2008_ADC_12BITS:
+ ts->read_x = TSC2008_START | TSC2008_MEASURE_X
+ | TSC2008_12BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+ ts->read_y = TSC2008_START | TSC2008_MEASURE_Y
+ | TSC2008_12BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+ ts->read_z1 = TSC2008_START | TSC2008_MEASURE_Z1
+ | TSC2008_12BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+ ts->read_z2 = TSC2008_START | TSC2008_MEASURE_Z2
+ | TSC2008_12BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+
+ input_set_abs_params(input, ABS_X, 0, 4096, 0, 0);
+ input_set_abs_params(input, ABS_Y, 0, 4096, 0, 0);
+ input_set_abs_params(input, ABS_PRESSURE, 0, 4096, 0,
0);
+ break;
+ case TSC2008_ADC_8BITS:
+ ts->read_x = TSC2008_START | TSC2008_MEASURE_X
+ | TSC2008_8BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+ ts->read_y = TSC2008_START | TSC2008_MEASURE_Y
+ | TSC2008_8BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+ ts->read_z1 = TSC2008_START | TSC2008_MEASURE_Z1
+ | TSC2008_8BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+ ts->read_z2 = TSC2008_START | TSC2008_MEASURE_Z2
+ | TSC2008_8BIT | TSC2008_REF_DIFF
+ | TSC2008_ADC_ON_IRQ_DIS0;
+
+ input_set_abs_params(input, ABS_X, 0, 256, 0, 0);
+ input_set_abs_params(input, ABS_Y, 0, 256, 0, 0);
+ input_set_abs_params(input, ABS_PRESSURE, 0, 256, 0, 0);
+ break;
+ }
+
+ /* Register the IRQ */
+ err = request_irq(ts->irq, tsc2008_handle_penirq,
IRQF_TRIGGER_FALLING,
+ spi->dev.driver->name, ts);
+ if (err < 0) {
+ dev_err(&spi->dev, "irq %d busy?\n", spi->irq);
+ goto err_free_mem;
+ }
+
+ /* Register the input driver */
+ err = input_register_device(input);
+ if (err)
+ goto err_free_irq;
+
+ /* Reset the controller */
+ tx_buf = TSC2008_SOFTWARE_RESET;
+ err = spi_write(spi, &tx_buf, 1);
+ if (err < 0)
+ goto err_free_irq;
+ udelay(200);
+
+ /* Initialize the controller */
+ tx_buf = TSC2008_START | TSC2008_SETUP;
+ switch (pdata->pull_up) {
+ case 50:
+ tx_buf |= TSC2008_PENIRQ_50_OHM;
+ break;
+ case 90:
+ tx_buf |= TSC2008_PENIRQ_90_OHM;
+ break;
+ }
+ switch (pdata->mav) {
+ case 0:
+ tx_buf |= TSC2008_MAV_ENABLE;
+ break;
+ case 1:
+ tx_buf |= TSC2008_MAV_BYPASS;
+ break;
+ }
+ err = spi_write(spi, &tx_buf, 1);
+ if (err < 0)
+ goto err_free_irq;
+ udelay(200);
+
+ /* Create the SPI message queue */
+ tsc2008_spi_setup(ts);
+
+ dev_info(&spi->dev, "touchscreen registered with irq (%d)\n",
spi->irq);
+
+ return 0;
+
+ err_free_irq:
+ free_irq(spi->irq, ts);
+ err_free_mem:
+ input_free_device(input);
+ kfree(ts);
+ return err;
+}
+
+static int __devexit tsc2008_remove(struct spi_device *spi)
+{
+ struct tsc2008 *ts = dev_get_drvdata(&spi->dev);
+
+ input_unregister_device(ts->input);
+ free_irq(ts->spi->irq, ts);
+ kfree(ts);
+
+ dev_dbg(&spi->dev, "unregistered touchscreen\n");
+ return 0;
+}
+
+static struct spi_driver tsc2008_driver = {
+ .driver = {
+ .name = "tsc2008",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = tsc2008_probe,
+ .remove = __devexit_p(tsc2008_remove),
+};
+
+static int __init tsc2008_init(void)
+{
+ return spi_register_driver(&tsc2008_driver);
+}
+
+static void __exit tsc2008_exit(void)
+{
+ spi_unregister_driver(&tsc2008_driver);
+}
+
+MODULE_AUTHOR("Chris Verges <chrisv@xxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments TSC2008 TouchScreen driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+
+module_init(tsc2008_init);
+module_exit(tsc2008_exit);
Index: drivers/input/touchscreen/Makefile
===================================================================
--- linux-2.6.29.3-orig/drivers/input/touchscreen/Makefile
(revision 11)
+++ linux-2.6.29.3/drivers/input/touchscreen/Makefile (revision 32)
@@ -26,6 +26,7 @@
obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
obj-$(CONFIG_TOUCHSCREEN_TSC2007) += tsc2007.o
+obj-$(CONFIG_TOUCHSCREEN_TSC2008) += tsc2008.o
obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o
obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001) += wacom_w8001.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX) += wm97xx-ts.o
--
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