Add support for the i.MX28 EVK

This patch was originally put together in January 2011 by Roshni.

1 files changed, 422 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/stmp3xxx_ts.c b/drivers/input/touchscreen/stmp3xxx_ts.c
new file mode 100644
index 000000000000..4e6ab20ea780
--- /dev/null
+++ b/drivers/input/touchscreen/stmp3xxx_ts.c
@@ -0,0 +1,422 @@
+/*
+ * Freesclae STMP37XX/STMP378X Touchscreen driver
+ *
+ * Author: Vitaly Wool <vital@embeddedalley.com>
+ *
+ * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+/* #define DEBUG*/
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+
+#include <mach/lradc.h>
+#include <mach/hardware.h>
+#include <mach/platform.h>
+#include <mach/regs-lradc.h>
+
+#define TOUCH_DEBOUNCE_TOLERANCE	100
+
+struct stmp3xxx_ts_info {
+	int touch_irq;
+	int device_irq;
+	struct input_dev *idev;
+	enum {
+		TS_STATE_DISABLED,
+		TS_STATE_TOUCH_DETECT,
+		TS_STATE_TOUCH_VERIFY,
+		TS_STATE_X_PLANE,
+		TS_STATE_Y_PLANE,
+	} state;
+	u16 x;
+	u16 y;
+	int sample_count;
+};
+
+static inline void enter_state_touch_detect(struct stmp3xxx_ts_info *info)
+{
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(2));
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(3));
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(4));
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(5));
+	__raw_writel(BM_LRADC_CTRL1_LRADC5_IRQ,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+	__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+	/*
+	 * turn off the yplus and yminus pullup and pulldown, and turn off touch
+	 * detect (enables yminus, and xplus through a resistor.On a press,
+	 * xplus is pulled down)
+	 */
+	__raw_writel(BM_LRADC_CTRL0_YMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_YPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_SET);
+
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 0);
+	info->state = TS_STATE_TOUCH_DETECT;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_disabled(struct stmp3xxx_ts_info *info)
+{
+	__raw_writel(BM_LRADC_CTRL0_YMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_YPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 0);
+	info->state = TS_STATE_DISABLED;
+	info->sample_count = 0;
+}
+
+
+static inline void enter_state_x_plane(struct stmp3xxx_ts_info *info)
+{
+	__raw_writel(BM_LRADC_CTRL0_YMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_SET);
+	__raw_writel(BM_LRADC_CTRL0_YPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_SET);
+	__raw_writel(BM_LRADC_CTRL0_XMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+
+	info->state = TS_STATE_X_PLANE;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_y_plane(struct stmp3xxx_ts_info *info)
+{
+	__raw_writel(BM_LRADC_CTRL0_YMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_YPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_SET);
+	__raw_writel(BM_LRADC_CTRL0_XPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_SET);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+	info->state = TS_STATE_Y_PLANE;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_touch_verify(struct stmp3xxx_ts_info *info)
+{
+	__raw_writel(BM_LRADC_CTRL0_YMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_YPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XMINUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_XPLUS_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		REGS_LRADC_BASE + HW_LRADC_CTRL0_SET);
+
+	info->state = TS_STATE_TOUCH_VERIFY;
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+	info->sample_count = 0;
+}
+
+static void process_lradc(struct stmp3xxx_ts_info *info, u16 x, u16 y,
+			int pressure)
+{
+	switch (info->state) {
+	case TS_STATE_X_PLANE:
+		pr_debug("%s: x plane state, sample_count %d\n", __func__,
+				info->sample_count);
+		if (info->sample_count < 2) {
+			info->x = x;
+			info->sample_count++;
+		} else {
+			if (abs(info->x - x) > TOUCH_DEBOUNCE_TOLERANCE)
+				info->sample_count = 1;
+			else {
+				u16 x_c = info->x * (info->sample_count - 1);
+				info->x = (x_c + x) / info->sample_count;
+				info->sample_count++;
+			}
+		}
+		if (info->sample_count > 4)
+			enter_state_y_plane(info);
+		else
+			hw_lradc_set_delay_trigger_kick(
+					LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+		break;
+
+	case TS_STATE_Y_PLANE:
+		pr_debug("%s: y plane state, sample_count %d\n", __func__,
+				info->sample_count);
+		if (info->sample_count < 2) {
+			info->y = y;
+			info->sample_count++;
+		} else {
+			if (abs(info->y - y) > TOUCH_DEBOUNCE_TOLERANCE)
+				info->sample_count = 1;
+			else {
+				u16 y_c = info->y * (info->sample_count - 1);
+				info->y = (y_c + y) / info->sample_count;
+				info->sample_count++;
+			}
+		}
+		if (info->sample_count > 4)
+			enter_state_touch_verify(info);
+		else
+			hw_lradc_set_delay_trigger_kick(
+					LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+		break;
+
+	case TS_STATE_TOUCH_VERIFY:
+		pr_debug("%s: touch verify state, sample_count %d\n", __func__,
+				info->sample_count);
+		pr_debug("%s: x %d, y %d\n", __func__, info->x, info->y);
+		input_report_abs(info->idev, ABS_X, info->x);
+		input_report_abs(info->idev, ABS_Y, info->y);
+		input_report_abs(info->idev, ABS_PRESSURE, pressure);
+		input_sync(info->idev);
+		/* fall through */
+	case TS_STATE_TOUCH_DETECT:
+		pr_debug("%s: touch detect state, sample_count %d\n", __func__,
+				info->sample_count);
+		if (pressure) {
+			input_report_abs(info->idev, ABS_PRESSURE, pressure);
+			enter_state_x_plane(info);
+			hw_lradc_set_delay_trigger_kick(
+					LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+		} else
+			enter_state_touch_detect(info);
+		break;
+
+	default:
+		printk(KERN_ERR "%s: unknown touchscreen state %d\n", __func__,
+				info->state);
+	}
+}
+
+static irqreturn_t ts_handler(int irq, void *dev_id)
+{
+	struct stmp3xxx_ts_info *info = dev_id;
+	u16 x_plus, y_plus;
+	int pressure = 0;
+
+	if (irq == info->touch_irq)
+		__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ,
+			REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+	else if (irq == info->device_irq)
+		__raw_writel(BM_LRADC_CTRL1_LRADC5_IRQ,
+			REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+
+	/* get x, y values */
+	x_plus = __raw_readl(REGS_LRADC_BASE + HW_LRADC_CHn(LRADC_TOUCH_X_PLUS)) & BM_LRADC_CHn_VALUE;
+	y_plus = __raw_readl(REGS_LRADC_BASE + HW_LRADC_CHn(LRADC_TOUCH_Y_PLUS)) & BM_LRADC_CHn_VALUE;
+
+	/* pressed? */
+	if (__raw_readl(REGS_LRADC_BASE + HW_LRADC_STATUS) & BM_LRADC_STATUS_TOUCH_DETECT_RAW)
+		pressure = 1;
+
+	pr_debug("%s: irq %d, x_plus %d, y_plus %d, pressure %d\n",
+			__func__, irq, x_plus, y_plus, pressure);
+
+	process_lradc(info, x_plus, y_plus, pressure);
+
+	return IRQ_HANDLED;
+}
+
+static int stmp3xxx_ts_probe(struct platform_device *pdev)
+{
+	struct input_dev *idev;
+	struct stmp3xxx_ts_info *info;
+	int ret = 0;
+	struct resource *res;
+
+	idev = input_allocate_device();
+	info = kzalloc(sizeof(struct stmp3xxx_ts_info), GFP_KERNEL);
+	if (idev == NULL || info == NULL) {
+		ret = -ENOMEM;
+		goto out_nomem;
+	}
+
+	idev->name = "STMP3XXX touchscreen";
+	idev->evbit[0] = BIT(EV_ABS);
+	input_set_abs_params(idev, ABS_X, 0, 0xFFF, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xFFF, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0, 1, 0, 0);
+
+	ret = input_register_device(idev);
+	if (ret)
+		goto out_nomem;
+
+	info->idev = idev;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		printk(KERN_ERR "%s: couldn't get IRQ resource\n", __func__);
+		ret = -ENODEV;
+		goto out_nodev;
+	}
+	info->touch_irq = res->start;
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+	if (!res) {
+		printk(KERN_ERR "%s: couldn't get IRQ resource\n", __func__);
+		ret = -ENODEV;
+		goto out_nodev;
+	}
+	info->device_irq = res->start;
+
+	ret = request_irq(info->touch_irq, ts_handler, IRQF_DISABLED,
+				"stmp3xxx_ts_touch", info);
+	if (ret)
+		goto out_nodev;
+
+	ret = request_irq(info->device_irq, ts_handler, IRQF_DISABLED,
+				"stmp3xxx_ts_dev", info);
+	if (ret) {
+		free_irq(info->touch_irq, info);
+		goto out_nodev;
+	}
+	enter_state_touch_detect(info);
+
+	hw_lradc_use_channel(LRADC_CH2);
+	hw_lradc_use_channel(LRADC_CH3);
+	hw_lradc_use_channel(LRADC_CH5);
+	hw_lradc_configure_channel(LRADC_CH2, 0, 0, 0);
+	hw_lradc_configure_channel(LRADC_CH3, 0, 0, 0);
+	hw_lradc_configure_channel(LRADC_CH5, 0, 0, 0);
+
+	/* Clear the accumulator & NUM_SAMPLES for the channels */
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(LRADC_CH2));
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(LRADC_CH3));
+	__raw_writel(0xFFFFFFFF, REGS_LRADC_BASE + HW_LRADC_CHn_CLR(LRADC_CH5));
+
+	hw_lradc_set_delay_trigger(LRADC_DELAY_TRIGGER_TOUCHSCREEN,
+			0x3c, 0, 0, 8);
+
+	__raw_writel(BM_LRADC_CTRL1_LRADC5_IRQ,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+	__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+
+	__raw_writel(BM_LRADC_CTRL1_LRADC5_IRQ_EN,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_SET);
+	__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_SET);
+
+	platform_set_drvdata(pdev, info);
+	device_init_wakeup(&pdev->dev, 1);
+	goto out;
+
+out_nodev:
+	input_free_device(idev);
+out_nomem:
+	kfree(idev);
+	kfree(info);
+out:
+	return ret;
+}
+
+static int stmp3xxx_ts_remove(struct platform_device *pdev)
+{
+	struct stmp3xxx_ts_info *info = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	hw_lradc_unuse_channel(LRADC_CH2);
+	hw_lradc_unuse_channel(LRADC_CH3);
+	hw_lradc_unuse_channel(LRADC_CH5);
+	__raw_writel(BM_LRADC_CTRL1_LRADC5_IRQ_EN,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+	__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+		REGS_LRADC_BASE + HW_LRADC_CTRL1_CLR);
+
+	free_irq(info->device_irq, info);
+	free_irq(info->touch_irq, info);
+	input_free_device(info->idev);
+
+	enter_state_disabled(info);
+	kfree(info->idev);
+	kfree(info);
+	return 0;
+}
+
+static int stmp3xxx_ts_suspend(struct platform_device *pdev,
+				pm_message_t state)
+{
+#ifdef CONFIG_PM
+	if (!device_may_wakeup(&pdev->dev)) {
+		hw_lradc_unuse_channel(LRADC_CH2);
+		hw_lradc_unuse_channel(LRADC_CH3);
+		hw_lradc_unuse_channel(LRADC_CH5);
+	}
+#endif
+	return 0;
+}
+
+static int stmp3xxx_ts_resume(struct platform_device *pdev)
+{
+#ifdef CONFIG_PM
+	if (!device_may_wakeup(&pdev->dev)) {
+		hw_lradc_use_channel(LRADC_CH2);
+		hw_lradc_use_channel(LRADC_CH3);
+		hw_lradc_use_channel(LRADC_CH5);
+	}
+#endif
+	return 0;
+}
+
+static struct platform_driver stmp3xxx_ts_driver = {
+	.probe		= stmp3xxx_ts_probe,
+	.remove		= stmp3xxx_ts_remove,
+	.suspend	= stmp3xxx_ts_suspend,
+	.resume		= stmp3xxx_ts_resume,
+	.driver		= {
+		.name		= "stmp3xxx_ts",
+	},
+};
+
+static int __init stmp3xxx_ts_init(void)
+{
+	return platform_driver_register(&stmp3xxx_ts_driver);
+}
+
+static void __exit stmp3xxx_ts_exit(void)
+{
+	platform_driver_unregister(&stmp3xxx_ts_driver);
+}
+
+module_init(stmp3xxx_ts_init);
+module_exit(stmp3xxx_ts_exit);