The atmel tsadcc is a touchscreen/adc controller found on the AT91SAM9RL SoC.
This driver provides basic support for this controller for use as a
touchscreen. Some future improvements include suspend/resume capabilities and
debugfs support.
Signed-off-by: Justin Waters <justin.waters@xxxxxxxxxxx>
---
drivers/input/touchscreen/Kconfig | 11 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/atmel_tsadcc.c | 375 ++++++++++++++++++++++++++++++
include/linux/atmel_tsadcc.h | 89 +++++++
4 files changed, 476 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/touchscreen/atmel_tsadcc.c
create mode 100644 include/linux/atmel_tsadcc.h
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 90e8e92..6e76eff 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -170,6 +170,17 @@ config TOUCHSCREEN_TOUCHWIN
To compile this driver as a module, choose M here: the
module will be called touchwin.
+config TOUCHSCREEN_ATMEL_TSADCC
+ tristate "Atmel Touchscreen Interface"
+ help
+ Say Y here if you have a 4-wire touchscreen connected to the
+ ADC Controller on your Atmel SoC (such as the AT91SAM9RL).
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called atmel_tsadcc.
+
config TOUCHSCREEN_UCB1400
tristate "Philips UCB1400 touchscreen"
select AC97_BUS
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 35d4097..3302e27 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -18,4 +18,5 @@ obj-$(CONFIG_TOUCHSCREEN_USB_COMPOSITE) += usbtouchscreen.o
obj-$(CONFIG_TOUCHSCREEN_PENMOUNT) += penmount.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT) += touchright.o
obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN) += touchwin.o
+obj-$(CONFIG_TOUCHSCREEN_ATMEL_TSADCC) += atmel_tsadcc.o
obj-$(CONFIG_TOUCHSCREEN_UCB1400) += ucb1400_ts.o
diff --git a/drivers/input/touchscreen/atmel_tsadcc.c b/drivers/input/touchscreen/atmel_tsadcc.c
new file mode 100644
index 0000000..b8a0984
--- /dev/null
+++ b/drivers/input/touchscreen/atmel_tsadcc.c
@@ -0,0 +1,375 @@
+/*
+ * Atmel TSADCC touchscreen sensor driver
+ *
+ * Copyright (c) 2008 TimeSys Corporation
+ * Copyright (c) 2008 Justin Waters
+ *
+ * Based on touchscreen code from Atmel Corporation
+ * and on the ads7846 driver by David Brownell.
+ *
+ * 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/hwmon.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <asm/irq.h>
+#include <linux/atmel_tsadcc.h>
+
+/*
+ * This code has been heavily tested on the Atmel at91sam9rl-ek
+ */
+
+/* These values are dependent upon the performance of the ADC. Ideally,
+ * These should be as close to the startup time and debounce time as
+ * possible (without going over). These assume an optimally setup ADC as
+ * per the electrical characteristics of the AT91SAM9RL tsadcc module
+ */
+#define TS_POLL_DELAY (1 * 1000000) /* ns delay before the first sample */
+#define TS_POLL_PERIOD (5 * 1000000) /* ns delay between samples */
+
+/*--------------------------------------------------------------------------*/
+
+static inline void atmel_tsadcc_getevent(struct atmel_tsadcc *ts)
+{
+ unsigned int regbuf;
+
+ /*
+ * Calculate the X Coordinates
+ * x = (ATMEL_TSADCC_CDR3 * 1024) / ATMEL_TSADCC_CDR2
+ */
+ regbuf = atmel_tsadcc_readreg(ATMEL_TSADCC_CDR2);
+ if (regbuf)
+ regbuf = atmel_tsadcc_readreg(ATMEL_TSADCC_CDR3) * 1024 / regbuf;
+ ts->event.x = regbuf;
+
+ /*
+ * Calculate the Y Coordinates
+ * y = (ATMEL_TSADCC_CDR1 * 1024) / ATMEL_TSADCC_CDR0
+ */
+ regbuf = atmel_tsadcc_readreg(ATMEL_TSADCC_CDR0);
+ if (regbuf)
+ regbuf = atmel_tsadcc_readreg(ATMEL_TSADCC_CDR1) * 1024 / regbuf;
+ ts->event.y = regbuf;
+
+ dev_dbg (&ts->pdev->dev, "X=%08X Y=%08X\n", ts->event.x, ts->event.y);
+
+ return;
+}
+
+/*--------------------------------------------------------------------------*/
+/*
+ * Touchscreen Interrupts
+ *
+ * The TSADCC Touchscreen provides a number of hardware interrupts. For this
+ * driver, we enable the PENCNT and NOCNT interrupts, which signal an interrupt
+ * when the pen either makes or breaks contact with the screen. When the pen
+ * is detected, we enable a timer that triggers the ADC periodically and polls
+ * the results. The timer resets itself only as long as the pen is making
+ * contact. Once the pen is lifted, the timer is no longer refreshed and the
+ * button and pressure is reduced to zero.
+ */
+static enum hrtimer_restart atmel_tsadcc_timer(struct hrtimer *handle)
+{
+ struct atmel_tsadcc *ts = container_of(handle, struct atmel_tsadcc, timer);
+ unsigned long flags;
+ unsigned int status;
+
+ spin_lock_irqsave(&ts->lock, flags);
+
+ /* Read the status register */
+ status = atmel_tsadcc_readreg(ATMEL_TSADCC_SR);
+
+ /* If the data is ready, read it! */
+ if(status & 0xF)
+ {
+ /* Read the LCDR Register to clear the DRDY bit */
+ atmel_tsadcc_readreg(ATMEL_TSADCC_LCDR);
+
+ dev_dbg (&ts->pdev->dev,"Status=0x%08X\n",status);
+
+ /* Pen remains down */
+ atmel_tsadcc_getevent(ts);
+
+ input_report_abs(ts->input, ABS_X, ts->event.x);
+ input_report_abs(ts->input, ABS_Y, ts->event.y);
+ input_report_abs(ts->input, ABS_PRESSURE, 7500);
+
+ input_sync(ts->input);
+
+ if(ts->pendown) {
+ /* Make ADC perform another conversion */
+ atmel_tsadcc_writereg(ATMEL_TSADCC_CR,2);
+
+ hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+ HRTIMER_MODE_REL);
+ }
+ }
+
+ spin_unlock_irq(&ts->lock);
+ return HRTIMER_NORESTART;
+}
+
+static irqreturn_t atmel_tsadcc_irq(int irq, void *handle)
+{
+ struct atmel_tsadcc *ts = handle;
+ unsigned long flags;
+ unsigned int status;
+
+ spin_lock_irqsave(&ts->lock, flags);
+
+ /* Read the status register */
+ status = atmel_tsadcc_readreg(ATMEL_TSADCC_SR);
+
+ /* Read the LCDR Register to clear the DRDY bit */
+ atmel_tsadcc_readreg(ATMEL_TSADCC_LCDR);
+
+ dev_dbg (&ts->pdev->dev,"Status=0x%08X\n",status);
+
+ if (ts->pendown) {
+ if (status & (1 << 21)) { /* Pen Up Event */
+ dev_dbg (&ts->pdev->dev, "Pen up\n");
+
+ ts->pendown = 0;
+
+ atmel_tsadcc_getevent(ts);
+
+ input_report_key(ts->input, BTN_TOUCH, 0);
+ input_report_abs(ts->input, ABS_PRESSURE, 0);
+ input_sync(ts->input);
+ }
+ } else if (status & (1 << 20)) { /* Pen first down */
+ dev_dbg (&ts->pdev->dev, "Pen down\n");
+
+ ts->pendown = 1;
+
+ atmel_tsadcc_getevent(ts);
+
+ input_report_key(ts->input, BTN_TOUCH, 1);
+ input_report_abs(ts->input, ABS_X, ts->event.x);
+ input_report_abs(ts->input, ABS_Y, ts->event.y);
+ input_report_abs(ts->input, ABS_PRESSURE, 1);
+
+ input_sync(ts->input);
+
+ /* Set up polling timer */
+ hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
+ HRTIMER_MODE_REL);
+ }
+
+ spin_unlock_irqrestore(&ts->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+/*--------------------------------------------------------------------------*/
+/* TODO: Create power save features */
+static int atmel_tsadcc_suspend(struct platform_device *pdev, pm_message_t message)
+{
+ return 0;
+}
+
+static int atmel_tsadcc_resume(struct platform_device *pdev)
+{
+ return 0;
+}
+
+/*--------------------------------------------------------------------------*/
+
+static int __devinit atmel_tsadcc_probe(struct platform_device *pdev)
+{
+ struct atmel_tsadcc *ts;
+ struct input_dev *input_dev;
+ struct atmel_tsadcc_platform_data *pdata = pdev->dev.platform_data;
+ int err;
+ struct resource *res;
+ unsigned int regbuf;
+
+ dev_dbg(&pdev->dev,"Begin probe\n");
+
+ /* Check Resources */
+ if (pdev->num_resources != 2) {
+ dev_err(&pdev->dev, "resources improperly configured\n");
+ return -ENODEV;
+ }
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "no platform data\n");
+ return -ENODEV;
+ }
+
+ /* Allocate memory for device */
+ ts = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!ts || !input_dev) {
+ err = -ENOMEM;
+ goto err_free_mem;
+ }
+ platform_set_drvdata(pdev, ts);
+
+ /* Set up polling timer */
+ hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ ts->timer.function = atmel_tsadcc_timer;
+
+ /* Touchscreen Information */
+ ts->pdev = pdev;
+ ts->input = input_dev;
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", pdev->dev.bus_id);
+ ts->reg_name = "Atmel TSADCC Regs";
+ ts->pendown = 0;
+
+ /* Input Device Information */
+ input_dev->name = "Atmel Touchscreen ADC Controller";
+ input_dev->phys = ts->phys;
+ 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, 0, 0x3FF, 0, 0);
+ input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);
+ input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15000, 0, 0);
+
+ /* Remap Register Memory */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ts->reg_start = res->start;
+ ts->reg_length = res->end - res->start +1;
+
+ if (!request_mem_region(ts->reg_start, ts->reg_length, ts->reg_name)) {
+ dev_err(&pdev->dev, "resources unavailable\n");
+ err = -EBUSY;
+ goto err_free_mem;
+ }
+
+ ts->reg = ioremap(ts->reg_start, ts->reg_length);
+ if (!ts->reg){
+ dev_err(&pdev->dev, "unable to remap register memory\n");
+ err = -ENOMEM;
+ goto err_release_mem;
+ }
+
+ /* Setup Clock */
+ ts->tsc_clk = clk_get(&pdev->dev,"tsc_clk");
+ if (IS_ERR(ts->tsc_clk)) {
+ dev_err(&pdev->dev, "unable to get clock\n");
+ err = PTR_ERR(ts->tsc_clk);
+ goto err_iounmap;
+ }
+ clk_enable(ts->tsc_clk);
+
+ regbuf = clk_get_rate(ts->tsc_clk);
+ dev_dbg (&pdev->dev,"Master clock is set at: %d Hz\n",regbuf);
+
+ /* Setup IRQ */
+ ts->irq = platform_get_irq(pdev, 0);
+ if (ts->irq < 0) {
+ dev_err(&pdev->dev, "unable to get IRQ\n");
+ err = -EBUSY;
+ goto err_clk_put;
+ }
+
+ /* Fill in initial Register Data */
+ ATMEL_TSADCC_RESET;
+ regbuf = (0x01 & 0x3) | /* TSAMOD */
+ ((0x0 & 0x1) << 5) | /* SLEEP */
+ ((0x1 & 0x1) << 6) | /* PENDET */
+ ((pdata->prescaler & 0x3F) << 8) | /* PRESCAL */
+ ((pdata->startup & 0x7F) << 16) | /* STARTUP */
+ ((pdata->debounce & 0x0F) << 28); /* PENDBC */
+ atmel_tsadcc_writereg(ATMEL_TSADCC_MR,regbuf);
+
+ regbuf = (0x4 & 0x7) | /* TRGMOD */
+ ((0xFFFF & 0xFFFF) << 16); /* TRGPER */
+ atmel_tsadcc_writereg(ATMEL_TSADCC_TRGR,regbuf);
+
+ regbuf = ((pdata->tsshtim & 0xF) << 24); /* TSSHTIM */
+ atmel_tsadcc_writereg(ATMEL_TSADCC_TSR,regbuf);
+
+ regbuf = atmel_tsadcc_readreg(ATMEL_TSADCC_IMR);
+ dev_dbg (&pdev->dev, "Initial IMR = %X\n", regbuf);
+
+ /* Register and enable IRQ */
+ if (request_irq(ts->irq, atmel_tsadcc_irq, IRQF_TRIGGER_LOW,
+ pdev->dev.driver->name, ts)) {
+ dev_dbg(&pdev->dev, "IRQ %d busy!\n", ts->irq);
+ err = -EBUSY;
+ goto err_iounmap;
+ }
+ regbuf = ((0x1 & 0x1) << 20) | /* PENCNT */
+ ((0x1 & 0x1) << 21); /* NOCNT */
+ atmel_tsadcc_writereg(ATMEL_TSADCC_IER,regbuf);
+
+ regbuf = atmel_tsadcc_readreg(ATMEL_TSADCC_IMR);
+ dev_dbg (&pdev->dev, "Post-Enable IMR = %X\n", regbuf);
+
+ /* Register Input Device */
+ err = input_register_device(input_dev);
+ if (err)
+ goto err_free_irq;
+
+ return 0;
+
+ err_free_irq:
+ free_irq(ts->irq, ts);
+ err_clk_put:
+ clk_put(ts->tsc_clk);
+ err_iounmap:
+ iounmap(ts->reg);
+ err_release_mem:
+ release_mem_region(ts->reg_start, ts->reg_length);
+ err_free_mem:
+ dev_dbg(&pdev->dev, "Error occurred: Freeing Memory!\n");
+ input_free_device(input_dev);
+ kfree(ts);
+ return err;
+}
+
+static int __devexit atmel_tsadcc_remove(struct platform_device *pdev)
+{
+ struct atmel_tsadcc *ts = dev_get_drvdata(&pdev->dev);
+
+ input_unregister_device(ts->input);
+
+ free_irq(ts->irq, ts);
+
+ /* Free Memory */
+ iounmap(ts->reg);
+ release_mem_region(ts->reg_start, ts->reg_length);
+ kfree(ts);
+
+ dev_dbg(&pdev->dev, "unregistered touchscreen\n");
+
+ return 0;
+}
+
+static struct platform_driver atmel_tsadcc_driver = {
+ .driver = {
+ .name = "atmel_tsadcc",
+ .owner = THIS_MODULE,
+ },
+ .probe = atmel_tsadcc_probe,
+ .remove = __devexit_p(atmel_tsadcc_remove),
+ .suspend = atmel_tsadcc_suspend,
+ .resume = atmel_tsadcc_resume,
+};
+
+static int __init atmel_tsadcc_init(void)
+{
+ return platform_driver_register(&atmel_tsadcc_driver);
+}
+module_init(atmel_tsadcc_init);
+
+static void __exit atmel_tsadcc_exit(void)
+{
+ platform_driver_unregister(&atmel_tsadcc_driver);
+}
+module_exit(atmel_tsadcc_exit);
+
+MODULE_DESCRIPTION("Atmel TSADCC Touchscreen Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/atmel_tsadcc.h b/include/linux/atmel_tsadcc.h
new file mode 100644
index 0000000..3199622
--- /dev/null
+++ b/include/linux/atmel_tsadcc.h
@@ -0,0 +1,89 @@
+/*
+ * Atmel TSADCC touchscreen sensor driver
+ *
+ * Copyright (c) 2008 TimeSys Corporation
+ * Copyright (c) 2008 Justin Waters
+ *
+ * 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.
+ */
+
+#ifndef _ATMEL_TSADCC_H
+#define _ATMEL_TSADCC_H
+
+/*--------------------------------------------------------------------------
+ * Register Locations
+ *
+ * From AT91SAM9RL64 User Guide, 15-Jan-08, Table 43-2
+ *--------------------------------------------------------------------------*/
+#define ATMEL_TSADCC_CR 0x00 /* Control (wo) */
+#define ATMEL_TSADCC_MR 0x04 /* Mode (rw) */
+#define ATMEL_TSADCC_TRGR 0x08 /* Trigger (rw) */
+#define ATMEL_TSADCC_TSR 0x0C /* Touch Screen (rw) */
+#define ATMEL_TSADCC_CHER 0x10 /* Channel Enable (wo) */
+#define ATMEL_TSADCC_CHDR 0x14 /* Channel Disable (wo) */
+#define ATMEL_TSADCC_CHSR 0x18 /* Channel Status (ro) */
+#define ATMEL_TSADCC_SR 0x1C /* Status (ro) */
+#define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data (ro) */
+#define ATMEL_TSADCC_IER 0x24 /* Interrupt Enable (wo) */
+#define ATMEL_TSADCC_IDR 0x28 /* Interrupt Disable (wo) */
+#define ATMEL_TSADCC_IMR 0x2C /* Interrupt Mask (ro) */
+#define ATMEL_TSADCC_CDR0 0x30 /* Channel Data 0 (ro) */
+#define ATMEL_TSADCC_CDR1 0x34 /* Channel Data 1 (ro) */
+#define ATMEL_TSADCC_CDR2 0x38 /* Channel Data 2 (ro) */
+#define ATMEL_TSADCC_CDR3 0x3C /* Channel Data 3 (ro) */
+#define ATMEL_TSADCC_CDR4 0x40 /* Channel Data 4 (ro) */
+#define ATMEL_TSADCC_CDR5 0x44 /* Channel Data 5 (ro) */
+
+/*--------------------------------------------------------------------------
+ * I/O Macros
+ *--------------------------------------------------------------------------*/
+#define atmel_tsadcc_readreg(a) ioread32(ts->reg + a)
+#define atmel_tsadcc_writereg(a,v) iowrite32(v,ts->reg + a)
+
+
+/*--------------------------------------------------------------------------
+ * Miscellaneous Macros
+ *--------------------------------------------------------------------------*/
+#define ATMEL_TSADCC_RESET atmel_tsadcc_writereg(ATMEL_TSADCC_CR,0x00000001)
+
+/*--------------------------------------------------------------------------
+ * Touchscreen Structs
+ *--------------------------------------------------------------------------*/
+
+struct ts_event {
+ unsigned int x;
+ unsigned int y;
+};
+
+struct atmel_tsadcc_platform_data {
+ unsigned int prescaler:6; /* ADC Clock Prescaler */
+ unsigned int debounce:4; /* Pen Debounce Period */
+ unsigned int tsshtim:4; /* Touchscreen Sample and Hold Time */
+ unsigned int startup:7; /* Startup time */
+};
+
+struct atmel_tsadcc {
+ struct input_dev *input;
+ char phys[32];
+ struct platform_device *pdev;
+ int irq;
+
+ void __iomem *reg;
+ const char *reg_name;
+ unsigned long reg_start;
+ unsigned long reg_length;
+
+ spinlock_t lock;
+
+ struct clk *tsc_clk;
+ struct hrtimer timer;
+ struct ts_event event;
+
+ unsigned int pendown;
+};
+
+/*--------------------------------------------------------------------------*/
+
+#endif /* _ATMEL_TSADCC_H */
--
1.5.4.3
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