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>

3 files changed, 408 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 61f35184f76..0069d9703fd 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -628,4 +628,14 @@ config TOUCHSCREEN_TPS6507X
           To compile this driver as a module, choose M here: the
           module will be called tps6507x_ts.
 
+config TOUCHSCREEN_STMPE
+        tristate "STMicroelectronics STMPE touchscreens"
+        depends on MFD_STMPE
+        help
+          Say Y here if you want support for STMicroelectronics
+          STMPE touchscreen controllers.
+
+          To compile this driver as a module, choose M here: the
+          module will be called stmpe-ts.
+
 endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index bd6f30b4ff7..28217e1dcaf 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_TOUCHSCREEN_PCAP)		+= pcap_ts.o
 obj-$(CONFIG_TOUCHSCREEN_PENMOUNT)      += penmount.o
 obj-$(CONFIG_TOUCHSCREEN_QT602240)      += qt602240_ts.o
 obj-$(CONFIG_TOUCHSCREEN_S3C2410)       += s3c2410_ts.o
+obj-$(CONFIG_TOUCHSCREEN_STMPE)         += stmpe-ts.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHIT213)    += touchit213.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHRIGHT)    += touchright.o
 obj-$(CONFIG_TOUCHSCREEN_TOUCHWIN)      += touchwin.o
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c
new file mode 100644
index 00000000000..77f4374b216
--- /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);