input: Touchscreen driver for TPS6507x

Add touch screen input driver for TPS6507x family of multi-function
chips.  Uses the TPS6507x MFD driver.  No interrupt support due to
testing limitations of current hardware.

Signed-off-by: Todd Fischer <todd.fischer@ridgerun.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 414 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index b9f58ca82fd..6703c6b9800 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -590,4 +590,17 @@ config TOUCHSCREEN_PCAP
 
           To compile this driver as a module, choose M here: the
           module will be called pcap_ts.
+
+config TOUCHSCREEN_TPS6507X
+        tristate "TPS6507x based touchscreens"
+        depends on I2C
+        help
+          Say Y here if you have a TPS6507x based touchscreen
+          controller.
+
+          If unsure, say N.
+
+          To compile this driver as a module, choose M here: the
+          module will be called tps6507x_ts.
+
 endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 8ad36eef90a..497964a7a21 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -46,3 +46,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_ATMEL)	+= atmel-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE)      += mainstone-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE)       += zylonite-wm97xx.o
 obj-$(CONFIG_TOUCHSCREEN_W90X900)       += w90p910_ts.o
+obj-$(CONFIG_TOUCHSCREEN_TPS6507X)      += tps6507x-ts.o
diff --git a/drivers/input/touchscreen/tps6507x-ts.c b/drivers/input/touchscreen/tps6507x-ts.c
new file mode 100644
index 00000000000..5de80a1a730
--- /dev/null
+++ b/drivers/input/touchscreen/tps6507x-ts.c
@@ -0,0 +1,400 @@
+/*
+ * drivers/input/touchscreen/tps6507x_ts.c
+ *
+ * Touchscreen driver for the tps6507x chip.
+ *
+ * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
+ *
+ * Credits:
+ *
+ *    Using code from tsc2007, MtekVision Co., Ltd.
+ *
+ * For licencing details see kernel-base/COPYING
+ *
+ * TPS65070, TPS65073, TPS650731, and TPS650732 support
+ * 10 bit touch screen interface.
+ */
+
+#include <linux/module.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/tps6507x.h>
+#include <linux/input/tps6507x-ts.h>
+#include <linux/delay.h>
+
+#define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
+#define TPS_DEFAULT_MIN_PRESSURE 0x30
+#define MAX_10BIT ((1 << 10) - 1)
+
+#define TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \
+                                         TPS6507X_ADCONFIG_START_CONVERSION | \
+                                         TPS6507X_ADCONFIG_INPUT_REAL_TSC)
+#define TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)
+
+struct ts_event {
+        u16     x;
+        u16     y;
+        u16     pressure;
+};
+
+struct tps6507x_ts {
+        struct input_dev        *input_dev;
+        struct device           *dev;
+        char                    phys[32];
+        struct workqueue_struct *wq;
+        struct delayed_work     work;
+        unsigned                polling;        /* polling is active */
+        struct ts_event         tc;
+        struct tps6507x_dev     *mfd;
+        u16                     model;
+        unsigned                pendown;
+        int                     irq;
+        void                    (*clear_penirq)(void);
+        unsigned long           poll_period;    /* ms */
+        u16                     min_pressure;
+        int                     vref;           /* non-zero to leave vref on */
+};
+
+static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)
+{
+        int err;
+
+        err = tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
+
+        if (err)
+                return err;
+
+        return 0;
+}
+
+static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
+{
+        return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
+}
+
+static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
+                                   u8 tsc_mode, u16 *value)
+{
+        s32 ret;
+        u8 adc_status;
+        u8 result;
+
+        /* Route input signal to A/D converter */
+
+        ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
+        if (ret) {
+                dev_err(tsc->dev, "TSC mode read failed\n");
+                goto err;
+        }
+
+        /* Start A/D conversion */
+
+        ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
+                                TPS6507X_ADCONFIG_CONVERT_TS);
+        if (ret) {
+                dev_err(tsc->dev, "ADC config write failed\n");
+                return ret;
+        }
+
+        do {
+                ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
+                                       &adc_status);
+                if (ret) {
+                        dev_err(tsc->dev, "ADC config read failed\n");
+                        goto err;
+                }
+        } while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);
+
+        ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
+        if (ret) {
+                dev_err(tsc->dev, "ADC result 2 read failed\n");
+                goto err;
+        }
+
+        *value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;
+
+        ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
+        if (ret) {
+                dev_err(tsc->dev, "ADC result 1 read failed\n");
+                goto err;
+        }
+
+        *value |= result;
+
+        dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);
+
+err:
+        return ret;
+}
+
+/* Need to call tps6507x_adc_standby() after using A/D converter for the
+ * touch screen interrupt to work properly.
+ */
+
+static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
+{
+        s32 ret;
+        s32 loops = 0;
+        u8 val;
+
+        ret = tps6507x_write_u8(tsc,  TPS6507X_REG_ADCONFIG,
+                                TPS6507X_ADCONFIG_INPUT_TSC);
+        if (ret)
+                return ret;
+
+        ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
+                                TPS6507X_TSCMODE_STANDBY);
+        if (ret)
+                return ret;
+
+        ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
+        if (ret)
+                return ret;
+
+        while (val & TPS6507X_REG_TSC_INT) {
+                mdelay(10);
+                ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
+                if (ret)
+                        return ret;
+                loops++;
+        }
+
+        return ret;
+}
+
+static void tps6507x_ts_handler(struct work_struct *work)
+{
+        struct tps6507x_ts *tsc =  container_of(work,
+                                struct tps6507x_ts, work.work);
+        struct input_dev *input_dev = tsc->input_dev;
+        int pendown;
+        int schd;
+        int poll = 0;
+        s32 ret;
+
+        ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
+                                       &tsc->tc.pressure);
+        if (ret)
+                goto done;
+
+        pendown = tsc->tc.pressure > tsc->min_pressure;
+
+        if (unlikely(!pendown && tsc->pendown)) {
+                dev_dbg(tsc->dev, "UP\n");
+                input_report_key(input_dev, BTN_TOUCH, 0);
+                input_report_abs(input_dev, ABS_PRESSURE, 0);
+                input_sync(input_dev);
+                tsc->pendown = 0;
+        }
+
+        if (pendown) {
+
+                if (!tsc->pendown) {
+                        dev_dbg(tsc->dev, "DOWN\n");
+                        input_report_key(input_dev, BTN_TOUCH, 1);
+                } else
+                        dev_dbg(tsc->dev, "still down\n");
+
+                ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
+                                               &tsc->tc.x);
+                if (ret)
+                        goto done;
+
+                ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
+                                               &tsc->tc.y);
+                if (ret)
+                        goto done;
+
+                input_report_abs(input_dev, ABS_X, tsc->tc.x);
+                input_report_abs(input_dev, ABS_Y, tsc->tc.y);
+                input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
+                input_sync(input_dev);
+                tsc->pendown = 1;
+                poll = 1;
+        }
+
+done:
+        /* always poll if not using interrupts */
+        poll = 1;
+
+        if (poll) {
+                schd = queue_delayed_work(tsc->wq, &tsc->work,
+                                          tsc->poll_period * HZ / 1000);
+                if (schd)
+                        tsc->polling = 1;
+                else {
+                        tsc->polling = 0;
+                        dev_err(tsc->dev, "re-schedule failed");
+                }
+        } else
+                tsc->polling = 0;
+
+        ret = tps6507x_adc_standby(tsc);
+}
+
+static int tps6507x_ts_probe(struct platform_device *pdev)
+{
+        int error;
+        struct tps6507x_ts *tsc;
+        struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
+        struct touchscreen_init_data *init_data;
+        struct input_dev *input_dev;
+        struct tps6507x_board *tps_board;
+        int schd;
+
+        /**
+         * tps_board points to pmic related constants
+         * coming from the board-evm file.
+         */
+
+        tps_board = (struct tps6507x_board *)tps6507x_dev->dev->platform_data;
+
+        if (!tps_board) {
+                dev_err(tps6507x_dev->dev,
+                        "Could not find tps6507x platform data\n");
+                return -EIO;
+        }
+
+        /**
+         * init_data points to array of regulator_init structures
+         * coming from the board-evm file.
+         */
+
+        init_data = tps_board->tps6507x_ts_init_data;
+
+        tsc = kzalloc(sizeof(struct tps6507x_ts), GFP_KERNEL);
+        if (!tsc) {
+                dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
+                error = -ENOMEM;
+                goto err0;
+        }
+
+        tps6507x_dev->ts = tsc;
+        tsc->mfd = tps6507x_dev;
+        tsc->dev = tps6507x_dev->dev;
+        input_dev = input_allocate_device();
+        if (!input_dev) {
+                dev_err(tsc->dev, "Failed to allocate input device.\n");
+                error = -ENOMEM;
+                goto err1;
+        }
+
+        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, MAX_10BIT, 0, 0);
+        input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
+        input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);
+
+        input_dev->name = "TPS6507x Touchscreen";
+        input_dev->id.bustype = BUS_I2C;
+        input_dev->dev.parent = tsc->dev;
+
+        snprintf(tsc->phys, sizeof(tsc->phys),
+                 "%s/input0", dev_name(tsc->dev));
+        input_dev->phys = tsc->phys;
+
+        dev_dbg(tsc->dev, "device: %s\n", input_dev->phys);
+
+        input_set_drvdata(input_dev, tsc);
+
+        tsc->input_dev = input_dev;
+
+        INIT_DELAYED_WORK(&tsc->work, tps6507x_ts_handler);
+        tsc->wq = create_workqueue("TPS6507x Touchscreen");
+
+        if (init_data) {
+                tsc->poll_period = init_data->poll_period;
+                tsc->vref = init_data->vref;
+                tsc->min_pressure = init_data->min_pressure;
+                input_dev->id.vendor = init_data->vendor;
+                input_dev->id.product = init_data->product;
+                input_dev->id.version = init_data->version;
+        } else {
+                tsc->poll_period = TSC_DEFAULT_POLL_PERIOD;
+                tsc->min_pressure = TPS_DEFAULT_MIN_PRESSURE;
+        }
+
+        error = tps6507x_adc_standby(tsc);
+        if (error)
+                goto err2;
+
+        error = input_register_device(input_dev);
+        if (error)
+                goto err2;
+
+        schd = queue_delayed_work(tsc->wq, &tsc->work,
+                                  tsc->poll_period * HZ / 1000);
+
+        if (schd)
+                tsc->polling = 1;
+        else {
+                tsc->polling = 0;
+                dev_err(tsc->dev, "schedule failed");
+                goto err2;
+         }
+
+        return 0;
+
+err2:
+        cancel_delayed_work(&tsc->work);
+        flush_workqueue(tsc->wq);
+        destroy_workqueue(tsc->wq);
+        tsc->wq = 0;
+        input_free_device(input_dev);
+err1:
+        kfree(tsc);
+        tps6507x_dev->ts = NULL;
+err0:
+        return error;
+}
+
+static int __devexit tps6507x_ts_remove(struct platform_device *pdev)
+{
+        struct tps6507x_dev *tps6507x_dev = platform_get_drvdata(pdev);
+        struct tps6507x_ts *tsc = tps6507x_dev->ts;
+        struct input_dev *input_dev = tsc->input_dev;
+
+        if (!tsc)
+                return 0;
+
+        cancel_delayed_work(&tsc->work);
+        flush_workqueue(tsc->wq);
+        destroy_workqueue(tsc->wq);
+        tsc->wq = 0;
+
+        input_free_device(input_dev);
+
+        tps6507x_dev->ts = NULL;
+        kfree(tsc);
+
+        return 0;
+}
+
+static struct platform_driver tps6507x_ts_driver = {
+        .driver = {
+                .name = "tps6507x-ts",
+                .owner = THIS_MODULE,
+        },
+        .probe = tps6507x_ts_probe,
+        .remove = __devexit_p(tps6507x_ts_remove),
+};
+
+static int __init tps6507x_ts_init(void)
+{
+        return platform_driver_register(&tps6507x_ts_driver);
+}
+module_init(tps6507x_ts_init);
+
+static void __exit tps6507x_ts_exit(void)
+{
+        platform_driver_unregister(&tps6507x_ts_driver);
+}
+module_exit(tps6507x_ts_exit);
+
+MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
+MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:tps6507x-tsc");