input: STMPE touch controller support

This one adds a driver for STMPE touchscreen controllers.
This driver depends on the stmpexxx mfd core driver.

Signed-off-by: Luotao Fu <l.fu@pengutronix.de>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 397 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
new file mode 100644
index 000000000000..77f4374b216d
--- /dev/null
+++ b/drivers/input/touchscreen/stmpe-ts.c
@@ -0,0 +1,397 @@
+/* STMicroelectronics STMPE811 Touchscreen Driver
+ *
+ * (C) 2010 Luotao Fu <l.fu@pengutronix.de>
+ * All rights reserved.
+ *
+ *  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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/stmpe.h>
+
+/* Register layouts and functionalities are identical on all stmpexxx variants
+ * with touchscreen controller
+ */
+#define STMPE_REG_INT_STA		0x0B
+#define STMPE_REG_ADC_CTRL1		0x20
+#define STMPE_REG_ADC_CTRL2		0x21
+#define STMPE_REG_TSC_CTRL		0x40
+#define STMPE_REG_TSC_CFG		0x41
+#define STMPE_REG_FIFO_TH		0x4A
+#define STMPE_REG_FIFO_STA		0x4B
+#define STMPE_REG_FIFO_SIZE		0x4C
+#define STMPE_REG_TSC_DATA_XYZ		0x52
+#define STMPE_REG_TSC_FRACTION_Z	0x56
+#define STMPE_REG_TSC_I_DRIVE		0x58
+
+#define OP_MOD_XYZ			0
+
+#define STMPE_TSC_CTRL_TSC_EN		(1<<0)
+
+#define STMPE_FIFO_STA_RESET		(1<<0)
+
+#define STMPE_IRQ_TOUCH_DET		0
+
+#define SAMPLE_TIME(x)			((x & 0xf) << 4)
+#define MOD_12B(x)			((x & 0x1) << 3)
+#define REF_SEL(x)			((x & 0x1) << 1)
+#define ADC_FREQ(x)			(x & 0x3)
+#define AVE_CTRL(x)			((x & 0x3) << 6)
+#define DET_DELAY(x)			((x & 0x7) << 3)
+#define SETTLING(x)			(x & 0x7)
+#define FRACTION_Z(x)			(x & 0x7)
+#define I_DRIVE(x)			(x & 0x1)
+#define OP_MODE(x)			((x & 0x7) << 1)
+
+#define STMPE_TS_NAME			"stmpe-ts"
+#define XY_MASK				0xfff
+
+struct stmpe_touch {
+	struct stmpe *stmpe;
+	struct input_dev *idev;
+	struct delayed_work work;
+	struct device *dev;
+	u8 sample_time;
+	u8 mod_12b;
+	u8 ref_sel;
+	u8 adc_freq;
+	u8 ave_ctrl;
+	u8 touch_det_delay;
+	u8 settling;
+	u8 fraction_z;
+	u8 i_drive;
+};
+
+static int __stmpe_reset_fifo(struct stmpe *stmpe)
+{
+	int ret;
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
+			STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
+	if (ret)
+		return ret;
+
+	return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
+			STMPE_FIFO_STA_RESET, 0);
+}
+
+static void stmpe_work(struct work_struct *work)
+{
+	int int_sta;
+	u32 timeout = 40;
+
+	struct stmpe_touch *ts =
+	    container_of(work, struct stmpe_touch, work.work);
+
+	int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
+
+	/*
+	 * touch_det sometimes get desasserted or just get stuck. This appears
+	 * to be a silicon bug, We still have to clearify this with the
+	 * manufacture. As a workaround We release the key anyway if the
+	 * touch_det keeps coming in after 4ms, while the FIFO contains no value
+	 * during the whole time.
+	 */
+	while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
+		timeout--;
+		int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
+		udelay(100);
+	}
+
+	/* reset the FIFO before we report release event */
+	__stmpe_reset_fifo(ts->stmpe);
+
+	input_report_abs(ts->idev, ABS_PRESSURE, 0);
+	input_sync(ts->idev);
+}
+
+static irqreturn_t stmpe_ts_handler(int irq, void *data)
+{
+	u8 data_set[4];
+	int x, y, z;
+	struct stmpe_touch *ts = data;
+
+	/*
+	 * Cancel scheduled polling for release if we have new value
+	 * available. Wait if the polling is already running.
+	 */
+	cancel_delayed_work_sync(&ts->work);
+
+	/*
+	 * The FIFO sometimes just crashes and stops generating interrupts. This
+	 * appears to be a silicon bug. We still have to clearify this with
+	 * the manufacture. As a workaround we disable the TSC while we are
+	 * collecting data and flush the FIFO after reading
+	 */
+	stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+				STMPE_TSC_CTRL_TSC_EN, 0);
+
+	stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
+
+	x = (data_set[0] << 4) | (data_set[1] >> 4);
+	y = ((data_set[1] & 0xf) << 8) | data_set[2];
+	z = data_set[3];
+
+	input_report_abs(ts->idev, ABS_X, x);
+	input_report_abs(ts->idev, ABS_Y, y);
+	input_report_abs(ts->idev, ABS_PRESSURE, z);
+	input_sync(ts->idev);
+
+       /* flush the FIFO after we have read out our values. */
+	__stmpe_reset_fifo(ts->stmpe);
+
+	/* reenable the tsc */
+	stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+			STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
+
+	/* start polling for touch_det to detect release */
+	schedule_delayed_work(&ts->work, HZ / 50);
+
+	return IRQ_HANDLED;
+}
+
+static int __devinit stmpe_init_hw(struct stmpe_touch *ts)
+{
+	int ret;
+	u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask;
+	struct stmpe *stmpe = ts->stmpe;
+	struct device *dev = ts->dev;
+
+	ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
+	if (ret) {
+		dev_err(dev, "Could not enable clock for ADC and TS\n");
+		return ret;
+	}
+
+	adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) |
+		REF_SEL(ts->ref_sel);
+	adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff);
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1,
+			adc_ctrl1_mask, adc_ctrl1);
+	if (ret) {
+		dev_err(dev, "Could not setup ADC\n");
+		return ret;
+	}
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2,
+			ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq));
+	if (ret) {
+		dev_err(dev, "Could not setup ADC\n");
+		return ret;
+	}
+
+	tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) |
+			SETTLING(ts->settling);
+	tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff);
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
+	if (ret) {
+		dev_err(dev, "Could not config touch\n");
+		return ret;
+	}
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
+			FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z));
+	if (ret) {
+		dev_err(dev, "Could not config touch\n");
+		return ret;
+	}
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
+			I_DRIVE(0xff), I_DRIVE(ts->i_drive));
+	if (ret) {
+		dev_err(dev, "Could not config touch\n");
+		return ret;
+	}
+
+	/* set FIFO to 1 for single point reading */
+	ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
+	if (ret) {
+		dev_err(dev, "Could not set FIFO\n");
+		return ret;
+	}
+
+	ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
+			OP_MODE(0xff), OP_MODE(OP_MOD_XYZ));
+	if (ret) {
+		dev_err(dev, "Could not set mode\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int stmpe_ts_open(struct input_dev *dev)
+{
+	struct stmpe_touch *ts = input_get_drvdata(dev);
+	int ret = 0;
+
+	ret = __stmpe_reset_fifo(ts->stmpe);
+	if (ret)
+		return ret;
+
+	return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+			STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
+}
+
+static void stmpe_ts_close(struct input_dev *dev)
+{
+	struct stmpe_touch *ts = input_get_drvdata(dev);
+
+	cancel_delayed_work_sync(&ts->work);
+
+	stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
+			STMPE_TSC_CTRL_TSC_EN, 0);
+}
+
+static int __devinit stmpe_input_probe(struct platform_device *pdev)
+{
+	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+	struct stmpe_platform_data *pdata = stmpe->pdata;
+	struct stmpe_touch *ts;
+	struct input_dev *idev;
+	struct stmpe_ts_platform_data *ts_pdata = NULL;
+	int ret = 0;
+	unsigned int ts_irq;
+
+	ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
+	if (ts_irq < 0)
+		return ts_irq;
+
+	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		goto err_out;
+
+	idev = input_allocate_device();
+	if (!idev)
+		goto err_free_ts;
+
+	platform_set_drvdata(pdev, ts);
+	ts->stmpe = stmpe;
+	ts->idev = idev;
+	ts->dev = &pdev->dev;
+
+	if (pdata)
+		ts_pdata = pdata->ts;
+
+	if (ts_pdata) {
+		ts->sample_time = ts_pdata->sample_time;
+		ts->mod_12b = ts_pdata->mod_12b;
+		ts->ref_sel = ts_pdata->ref_sel;
+		ts->adc_freq = ts_pdata->adc_freq;
+		ts->ave_ctrl = ts_pdata->ave_ctrl;
+		ts->touch_det_delay = ts_pdata->touch_det_delay;
+		ts->settling = ts_pdata->settling;
+		ts->fraction_z = ts_pdata->fraction_z;
+		ts->i_drive = ts_pdata->i_drive;
+	}
+
+	INIT_DELAYED_WORK(&ts->work, stmpe_work);
+
+	ret = request_threaded_irq(ts_irq, NULL, stmpe_ts_handler,
+			IRQF_ONESHOT, STMPE_TS_NAME, ts);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
+		goto err_free_input;
+	}
+
+	ret = stmpe_init_hw(ts);
+	if (ret)
+		goto err_free_irq;
+
+	idev->name = STMPE_TS_NAME;
+	idev->id.bustype = BUS_I2C;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+	idev->open = stmpe_ts_open;
+	idev->close = stmpe_ts_close;
+
+	input_set_drvdata(idev, ts);
+
+	input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register input device\n");
+		goto err_free_irq;
+	}
+
+	return ret;
+
+err_free_irq:
+	free_irq(ts_irq, ts);
+err_free_input:
+	input_free_device(idev);
+	platform_set_drvdata(pdev, NULL);
+err_free_ts:
+	kfree(ts);
+err_out:
+	return ret;
+}
+
+static int __devexit stmpe_ts_remove(struct platform_device *pdev)
+{
+	struct stmpe_touch *ts = platform_get_drvdata(pdev);
+	unsigned int ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
+
+	stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
+
+	free_irq(ts_irq, ts);
+
+	platform_set_drvdata(pdev, NULL);
+
+	input_unregister_device(ts->idev);
+	input_free_device(ts->idev);
+
+	kfree(ts);
+
+	return 0;
+}
+
+static struct platform_driver stmpe_ts_driver = {
+	.driver = {
+		   .name = STMPE_TS_NAME,
+		   .owner = THIS_MODULE,
+		   },
+	.probe = stmpe_input_probe,
+	.remove = __devexit_p(stmpe_ts_remove),
+};
+
+static int __init stmpe_ts_init(void)
+{
+	return platform_driver_register(&stmpe_ts_driver);
+}
+
+module_init(stmpe_ts_init);
+
+static void __exit stmpe_ts_exit(void)
+{
+	platform_driver_unregister(&stmpe_ts_driver);
+}
+
+module_exit(stmpe_ts_exit);
+
+MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
+MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" STMPE_TS_NAME);