input: Touchscreen driver for TPS6507x
Todd Fischer [Mon, 5 Apr 2010 23:53:12 +0000 (17:53 -0600)]
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>

drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/tps6507x-ts.c [new file with mode: 0644]
drivers/mfd/tps6507x.c
include/linux/input/tps6507x-ts.h [new file with mode: 0644]
include/linux/mfd/tps6507x.h

index b9f58ca..6703c6b 100644 (file)
@@ -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
index 8ad36ee..497964a 100644 (file)
@@ -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 (file)
index 0000000..5de80a1
--- /dev/null
@@ -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");
index c59f745..d859dff 100644 (file)
@@ -26,6 +26,9 @@ static struct mfd_cell tps6507x_devs[] = {
        {
                .name = "tps6507x-pmic",
        },
+       {
+               .name = "tps6507x-ts",
+       },
 };
 
 
diff --git a/include/linux/input/tps6507x-ts.h b/include/linux/input/tps6507x-ts.h
new file mode 100644 (file)
index 0000000..ab14403
--- /dev/null
@@ -0,0 +1,24 @@
+/* linux/i2c/tps6507x-ts.h
+ *
+ * Functions to access TPS65070 touch screen chip.
+ *
+ * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
+ *
+ *
+ *  For licencing details see kernel-base/COPYING
+ */
+
+#ifndef __LINUX_I2C_TPS6507X_TS_H
+#define __LINUX_I2C_TPS6507X_TS_H
+
+/* Board specific touch screen initial values */
+struct touchscreen_init_data {
+       int     poll_period;    /* ms */
+       int     vref;           /* non-zero to leave vref on */
+       __u16   min_pressure;   /* min reading to be treated as a touch */
+       __u16   vendor;
+       __u16   product;
+       __u16   version;
+};
+
+#endif /*  __LINUX_I2C_TPS6507X_TS_H */
index 9543cb7..c923e48 100644 (file)
 
 struct tps6507x_board {
        struct regulator_init_data *tps6507x_pmic_init_data;
+       struct touchscreen_init_data *tps6507x_ts_init_data;
 };
 
 /**
@@ -162,6 +163,7 @@ struct tps6507x_dev {
 
        /* Client devices */
        struct tps6507x_pmic *pmic;
+       struct tps6507x_ts *ts;
 };
 
 #endif /*  __LINUX_MFD_TPS6507X_H */