[PATCH] input/touch: Introduce the LPC32xx touchscreen controller driver (v2)
wellsk40 at gmail.com
wellsk40 at gmail.com
Mon Aug 16 17:21:01 EDT 2010
From: Kevin Wells <wellsk40 at gmail.com>
This patch set introduces support for the LPC32xx touchscreen
controller driver. The LPC32xx touchscreen controller supports
automated event detection and X/Y data conversion for resistive
touchscreens.
Signed-off-by: Kevin Wells <wellsk40 at gmail.com>
Signed-off-by: Durgesh Pattamatta <durgesh.pattamatta at nxp.com>
---
drivers/input/touchscreen/Kconfig | 10 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/lpc32xx_ts.c | 404 ++++++++++++++++++++++++++++++++
3 files changed, 415 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/touchscreen/lpc32xx_ts.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 0069d97..400c99d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -214,6 +214,16 @@ config TOUCHSCREEN_WACOM_W8001
To compile this driver as a module, choose M here: the
module will be called wacom_w8001.
+config TOUCHSCREEN_LPC32XX
+ tristate "LPC32XX touchscreen controller"
+ depends on ARCH_LPC32XX
+ help
+ Say Y here if you have a LPC32XX device and want
+ to support the built-in touchscreen.
+
+ To compile this driver as a module, choose M here: the
+ module will be called lpc32xx_ts.
+
config TOUCHSCREEN_MCS5000
tristate "MELFAS MCS-5000 touchscreen"
depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 28217e1..22e2d59 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_TOUCHSCREEN_EETI) += eeti_ts.o
obj-$(CONFIG_TOUCHSCREEN_ELO) += elo.o
obj-$(CONFIG_TOUCHSCREEN_FUJITSU) += fujitsu_ts.o
obj-$(CONFIG_TOUCHSCREEN_INEXIO) += inexio.o
+obj-$(CONFIG_TOUCHSCREEN_LPC32XX) += lpc32xx_ts.o
obj-$(CONFIG_TOUCHSCREEN_MC13783) += mc13783_ts.o
obj-$(CONFIG_TOUCHSCREEN_MCS5000) += mcs5000_ts.o
obj-$(CONFIG_TOUCHSCREEN_MIGOR) += migor_ts.o
diff --git a/drivers/input/touchscreen/lpc32xx_ts.c b/drivers/input/touchscreen/lpc32xx_ts.c
new file mode 100644
index 0000000..e67ce41
--- /dev/null
+++ b/drivers/input/touchscreen/lpc32xx_ts.c
@@ -0,0 +1,404 @@
+/*
+ * LPC32xx built-in touchscreen driver
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+/*
+ * Touchscreen controller register offsets
+ */
+#define LPC32XX_TSC_STAT 0x00
+#define LPC32XX_TSC_SEL 0x04
+#define LPC32XX_TSC_CON 0x08
+#define LPC32XX_TSC_FIFO 0x0C
+#define LPC32XX_TSC_DTR 0x10
+#define LPC32XX_TSC_RTR 0x14
+#define LPC32XX_TSC_UTR 0x18
+#define LPC32XX_TSC_TTR 0x1C
+#define LPC32XX_TSC_DXP 0x20
+#define LPC32XX_TSC_MIN_X 0x24
+#define LPC32XX_TSC_MAX_X 0x28
+#define LPC32XX_TSC_MIN_Y 0x2C
+#define LPC32XX_TSC_MAX_Y 0x30
+#define LPC32XX_TSC_AUX_UTR 0x34
+#define LPC32XX_TSC_AUX_MIN 0x38
+#define LPC32XX_TSC_AUX_MAX 0x3C
+
+#define LPC32XX_TSC_STAT_FIFO_OVRRN (1 << 8)
+#define LPC32XX_TSC_STAT_FIFO_EMPTY (1 << 7)
+
+#define LPC32XX_TSC_SEL_DEFVAL 0x0284
+
+#define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 (0x1 << 11)
+#define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s) ((10 - (s)) << 7)
+#define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s) ((10 - (s)) << 4)
+#define LPC32XX_TSC_ADCCON_POWER_UP (1 << 2)
+#define LPC32XX_TSC_ADCCON_AUTO_EN (1 << 0)
+
+#define LPC32XX_TSC_FIFO_TS_P_LEVEL (1 << 31)
+#define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x) (((x) & 0x03FF0000) >> 16)
+#define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y) ((y) & 0x000003FF)
+
+#define LPC32XX_TSC_ADCDAT_VALUE_MASK 0x000003FF
+
+#define LPC32XX_TSC_MIN_XY_VAL 0x0
+#define LPC32XX_TSC_MAX_XY_VAL 0x3FF
+
+#define MOD_NAME "ts-lpc32xx"
+
+#define tsc_readl(dev, reg) \
+ __raw_readl((dev)->tsc_base + (reg))
+#define tsc_writel(dev, reg, val) \
+ __raw_writel((val), (dev)->tsc_base + (reg))
+
+struct lpc32xx_tsc {
+ struct input_dev *dev;
+ void __iomem *tsc_base;
+ int irq;
+ struct clk *clk;
+};
+
+static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
+{
+ while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
+ LPC32XX_TSC_STAT_FIFO_EMPTY))
+ tsc_readl(tsc, LPC32XX_TSC_FIFO);
+}
+
+static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
+{
+ u32 tmp, rv[4], xs[4], ys[4];
+ int idx;
+ struct lpc32xx_tsc *tsc = dev_id;
+ struct input_dev *input = tsc->dev;
+
+ tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);
+
+ if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
+ /* FIFO overflow - throw away samples */
+ lpc32xx_fifo_clear(tsc);
+ return IRQ_HANDLED;
+ }
+
+ /*
+ * Gather and normalize 4 samples. Pen-up events may have less
+ * than 4 samples, but its ok to pop 4 and let the last sample
+ * pen status check drop the samples.
+ */
+ idx = 0;
+ while ((idx < 4) &&
+ (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
+ LPC32XX_TSC_STAT_FIFO_EMPTY))) {
+ tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
+ xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
+ LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
+ ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
+ LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
+ rv[idx] = tmp;
+ idx++;
+ }
+
+ /* Data is only valid if pen is still down in last sample */
+ if ((!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL)) && (idx == 4)) {
+ /* Use average of 2nd and 3rd sample for position */
+ input_report_abs(input, ABS_X, ((xs[1] + xs[2]) / 2));
+ input_report_abs(input, ABS_Y, ((ys[1] + ys[2]) / 2));
+ input_report_key(input, BTN_TOUCH, 1);
+ } else {
+ input_report_key(input, BTN_TOUCH, 0);
+ }
+
+ input_sync(input);
+
+ return IRQ_HANDLED;
+}
+
+static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
+{
+ /* Disable auto mode */
+ tsc_writel(tsc, LPC32XX_TSC_CON,
+ tsc_readl(tsc, LPC32XX_TSC_CON) &
+ ~LPC32XX_TSC_ADCCON_AUTO_EN);
+
+ clk_disable(tsc->clk);
+}
+
+static void lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
+{
+ u32 tmp;
+
+ clk_enable(tsc->clk);
+
+ tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;
+
+ /* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
+ tmp = (LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
+ LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
+ LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10));
+ tsc_writel(tsc, LPC32XX_TSC_CON, tmp);
+
+ /* These values are all preset */
+ tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
+ tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
+ tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
+ tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
+ tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);
+
+ /* Aux support is not used */
+ tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
+ tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
+ tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);
+
+ /*
+ * Set sample rate to about 240Hz per X/Y pair. A single measurement
+ * consists of 4 pairs which gives about a 60Hz sample rate based on
+ * a stable 32768Hz clock source. Values are in clocks.
+ * Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
+ */
+ tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
+ tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
+ tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
+ tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
+ tsc_writel(tsc, LPC32XX_TSC_UTR, 88);
+
+ lpc32xx_fifo_clear(tsc);
+
+ /* Enable automatic ts event capture */
+ tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);
+}
+
+static int lpc32xx_ts_open(struct input_dev *dev)
+{
+ struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
+
+ lpc32xx_setup_tsc(tsc);
+
+ return 0;
+}
+
+static void lpc32xx_ts_close(struct input_dev *dev)
+{
+ struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
+
+ lpc32xx_stop_tsc(tsc);
+}
+
+static int __devinit lpc32xx_ts_probe(struct platform_device *pdev)
+{
+ struct lpc32xx_tsc *tsc;
+ struct resource *res;
+ resource_size_t size;
+ int retval;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "Can't get memory resource\n");
+ return -ENOENT;
+ }
+
+ retval = platform_get_irq(pdev, 0);
+ if (retval < 0) {
+ dev_err(&pdev->dev, "Can't get interrupt resource\n");
+ return retval;
+ }
+
+ tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
+ if (unlikely(!tsc)) {
+ dev_err(&pdev->dev, "failed allocating memory\n");
+ return -ENOMEM;
+ }
+ tsc->irq = retval;
+
+ size = resource_size(res);
+
+ if (!request_mem_region(res->start, size, pdev->name)) {
+ dev_err(&pdev->dev, "TSC registers are not free\n");
+ retval = -EBUSY;
+ goto err_free_mem;
+ }
+
+ tsc->tsc_base = ioremap(res->start, size);
+ if (!tsc->tsc_base) {
+ dev_err(&pdev->dev, "Can't map memory\n");
+ retval = -ENOMEM;
+ goto err_release_mem;
+ }
+
+ tsc->dev = input_allocate_device();
+ if (!tsc->dev) {
+ dev_err(&pdev->dev, "failed allocating input device\n");
+ retval = -ENOMEM;
+ goto err_unmap;
+ }
+
+ tsc->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(tsc->clk)) {
+ dev_err(&pdev->dev, "failed getting clock\n");
+ retval = -ENOENT;
+ goto err_dealloc_dev;
+ }
+
+ platform_set_drvdata(pdev, tsc);
+ input_set_drvdata(tsc->dev, tsc);
+
+ tsc->dev->name = MOD_NAME;
+ tsc->dev->phys = "lpc32xx/input0";
+ tsc->dev->id.bustype = BUS_HOST;
+ tsc->dev->id.vendor = 0x0001;
+ tsc->dev->id.product = 0x0002;
+ tsc->dev->id.version = 0x0100;
+ tsc->dev->dev.parent = &pdev->dev;
+ tsc->dev->open = lpc32xx_ts_open;
+ tsc->dev->close = lpc32xx_ts_close;
+
+ tsc->dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ tsc->dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+ input_set_abs_params(tsc->dev, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
+ LPC32XX_TSC_MAX_XY_VAL, 0, 0);
+ input_set_abs_params(tsc->dev, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
+ LPC32XX_TSC_MAX_XY_VAL, 0, 0);
+
+ retval = input_register_device(tsc->dev);
+ if (retval) {
+ dev_err(&pdev->dev, "failed registering input device\n");
+ goto err_stop_clock;
+ }
+
+ retval = request_irq(tsc->irq, lpc32xx_ts_interrupt,
+ IRQF_DISABLED, pdev->name, tsc);
+ if (retval < 0) {
+ dev_err(&pdev->dev, "failed requesting interrupt\n");
+ goto err_unreg_dev;
+ }
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ return 0;
+
+err_unreg_dev:
+ input_unregister_device(tsc->dev);
+ tsc->dev = NULL;
+err_stop_clock:
+ clk_put(tsc->clk);
+err_dealloc_dev:
+ input_free_device(tsc->dev);
+err_unmap:
+ iounmap(tsc->tsc_base);
+err_release_mem:
+ release_mem_region(res->start, size);
+err_free_mem:
+ kfree(tsc);
+
+ return retval;
+}
+
+static int __devexit lpc32xx_ts_remove(struct platform_device *pdev)
+{
+ struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev);
+ struct resource *res;
+
+ device_init_wakeup(&pdev->dev, 0);
+ free_irq(tsc->irq, tsc);
+
+ input_unregister_device(tsc->dev);
+
+ clk_put(tsc->clk);
+
+ iounmap(tsc->tsc_base);
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(res->start, resource_size(res));
+
+ kfree(tsc);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int lpc32xx_ts_suspend(struct device *dev)
+{
+ struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
+
+ /*
+ * Suspend and resume can be called when the device hasn't been
+ * enabled. If there are no users that have the device open, then
+ * avoid calling the TSC stop and start functions as the TSC
+ * isn't yet clocked.
+ */
+ if (tsc->dev->users) {
+ if (device_may_wakeup(dev))
+ enable_irq_wake(tsc->irq);
+ else
+ lpc32xx_stop_tsc(tsc);
+ }
+
+ return 0;
+}
+
+static int lpc32xx_ts_resume(struct device *dev)
+{
+ struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
+
+ if (tsc->dev->users) {
+ if (device_may_wakeup(dev))
+ disable_irq_wake(tsc->irq);
+ else
+ lpc32xx_setup_tsc(tsc);
+ }
+
+ return 0;
+}
+
+static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
+ .suspend = lpc32xx_ts_suspend,
+ .resume = lpc32xx_ts_resume,
+};
+#define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
+#else
+#define LPC32XX_TS_PM_OPS NULL
+#endif
+
+static struct platform_driver lpc32xx_ts_driver = {
+ .probe = lpc32xx_ts_probe,
+ .remove = __devexit_p(lpc32xx_ts_remove),
+ .driver = {
+ .name = MOD_NAME,
+ .owner = THIS_MODULE,
+ .pm = LPC32XX_TS_PM_OPS,
+ },
+};
+
+static int __init lpc32xx_ts_init(void)
+{
+ return platform_driver_register(&lpc32xx_ts_driver);
+}
+module_init(lpc32xx_ts_init);
+
+static void __exit lpc32xx_ts_exit(void)
+{
+ platform_driver_unregister(&lpc32xx_ts_driver);
+}
+module_exit(lpc32xx_ts_exit);
+
+MODULE_AUTHOR("Kevin Wells <kevin.wells at nxp.com");
+MODULE_DESCRIPTION("LPC32XX TSC Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lpc32xx_ts");
--
1.7.1.1
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