Freescale KL25Z support from Alan Carvalho de Assis

8 files changed, 557 insertions, 3 deletions

diff --git a/nuttx/ChangeLog b/nuttx/ChangeLog
index fa28b0eff..8cd045ec6 100644
--- a/nuttx/ChangeLog
+++ b/nuttx/ChangeLog
@@ -5000,4 +5000,7 @@
 	  (2013-6-18)
 	* arch/arm/src/sam34/sam_spi.c:  Fix SPI mode setting.  In the SAM3/4
 	  family, the clock phase control (CPHA) is inverted (NPHA) (2013-6-18).
-
+	* arch/arm/src/kl/chip/kl_tsi.h: Freescale KL25Z TSI register
+	  definitions from Alan Carvalho de Assis (2013-6-18).
+	* configs/freedom-kl25z/src/kl_tsi.c:  Example TSI driver for the
+	  Freedom KL25Z board from Alan Carvalho de Assis (2013-6-18).
diff --git a/nuttx/arch/arm/src/kl/chip/kl_memorymap.h b/nuttx/arch/arm/src/kl/chip/kl_memorymap.h
index 60e4542c7..351c87e54 100644
--- a/nuttx/arch/arm/src/kl/chip/kl_memorymap.h
+++ b/nuttx/arch/arm/src/kl/chip/kl_memorymap.h
@@ -87,7 +87,7 @@
 # define KL_RTC_BASE       0x4003d000 /* Real time clock */
 # define KL_DAC0_BASE      0x4003f000 /* Digital-to-analog convert (DAC) 0 */
 # define KL_LPTMR_BASE     0x40040000 /* Low power timer */
-# define KL_TSI0_BASE      0x40045000 /* Touch sense interface */
+# define KL_TSI_BASE       0x40045000 /* Touch sense interface */
 # define KL_SIMLP_BASE     0x40047000 /* SIM low-power logic */
 # define KL_SIM_BASE       0x40048000 /* System integration module (SIM) */
 # define KL_PORT_BASE(n)   (0x40049000 + ((n) << 12))
diff --git a/nuttx/arch/arm/src/kl/chip/kl_tsi.h b/nuttx/arch/arm/src/kl/chip/kl_tsi.h
new file mode 100644
index 000000000..8e0d87e90
--- /dev/null
+++ b/nuttx/arch/arm/src/kl/chip/kl_tsi.h
@@ -0,0 +1,154 @@
+/************************************************************************************
+ * arch/arm/src/kl/chip/kl_tsi.h
+ *
+ *   Copyright (C) 2013 Alan Carvalho de Assis
+ *   Author: Alan Carvalho de Assis <acassis@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_KL_CHIP_KL_TSI_H
+#define __ARCH_ARM_SRC_KL_CHIP_KL_TSI_H
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+
+#include "chip.h"
+
+/************************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************************/
+
+/* Register Offsets *****************************************************************/
+
+#define KL_TSI_GENCS_OFFSET            0x0000 /* General Control and Status Register */
+#define KL_TSI_DATA_OFFSET             0x0004 /* SCAN control register */
+#define KL_TSI_TSHD_OFFSET             0x0008 /* Pin enable register */
+
+/* Register Addresses ***************************************************************/
+
+#define KL_TSI_GENCS                   (KL_TSI_BASE+KL_TSI_GENCS_OFFSET)
+#define KL_TSI_DATA                    (KL_TSI_BASE+KL_TSI_DATA_OFFSET)
+#define KL_TSI_TSHD                    (KL_TSI_BASE+KL_TSI_TSHD_OFFSET)
+
+/* Register Bit Definitions *********************************************************/
+
+/* General Control and Status Register */
+                                                 /* Bit 0: Reserved */
+#define TSI_GENCS_CURSW                (1 << 1)  /* Bit 1: Current sources for oscillators swapped */
+#define TSI_GENCS_EOSF                 (1 << 2)  /* Bit 2: End of scan flag */
+#define TSI_GENCS_SCNIP                (1 << 3)  /* Bit 3: Scan in progress status */
+#define TSI_GENCS_STM                  (1 << 4)  /* Bit 4: Scan trigger mode */
+#define TSI_GENCS_STPE                 (1 << 5)  /* Bit 5: TSI STOP enable */
+#define TSI_GENCS_TSIIEN               (1 << 6)  /* Bit 6: TSI module interrupt enable */
+#define TSI_GENCS_TSIEN                (1 << 7)  /* Bit 7: TSI module enable */
+#define TSI_GENCS_NSCN_SHIFT           (8)       /* Bits 8-12: Electrode oscillator count used in a scan */
+#define TSI_GENCS_NSCN_MASK            (31 << TSI_GENCS_NSCN_SHIFT)
+#  define TSI_GENCS_NSCN_TIMES(n)      (((n)-1) << TSI_GENCS_NSCN_SHIFT) /* n times per electrode,n=1..32 */
+#define TSI_GENCS_PS_SHIFT             (13)      /* Bits 13-15: Prescaler value */
+#define TSI_GENCS_PS_MASK              (7 << TSI_GENCS_PS_SHIFT)
+#  define TSI_GENCS_PS_DIV1            (0 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 1 */
+#  define TSI_GENCS_PS_DIV2            (1 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 2 */
+#  define TSI_GENCS_PS_DIV4            (2 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 4 */
+#  define TSI_GENCS_PS_DIV8            (3 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 8 */
+#  define TSI_GENCS_PS_DIV16           (4 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 16 */
+#  define TSI_GENCS_PS_DIV32           (5 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 32 */
+#  define TSI_GENCS_PS_DIV64           (6 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 64 */
+#  define TSI_GENCS_PS_DIV128          (7 << TSI_GENCS_PS_SHIFT) /* Electrode oscillator / 128 */
+#define TSI_GENCS_EXTCHRG_SHIFT        (16)      /* Bits 16-18: Electrode Osc charge/discharge value */
+#define TSI_GENCS_EXTCHRG_MASK         (7 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_500NA      (0 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_1UA        (1 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_2UA        (2 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_4UA        (3 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_8UA        (4 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_16UA       (5 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_32UA       (6 << TSI_GENCS_EXTCHRG_SHIFT)
+#  define TSI_GENCS_EXTCHRG_64A        (7 << TSI_GENCS_EXTCHRG_SHIFT)
+#define TSI_GENCS_DVOLT_SHIFT          (19)      /* Bits 19-20: Oscilattor voltage rails */
+#define TSI_GENCS_DVOLT_MASK           (3 << TSI_GENCS_DVOLT_SHIFT)
+#  define TSI_GENCS_DVOLT_1p03V        (0 << TSI_GENCS_DVOLT_SHIFT)
+#  define TSI_GENCS_DVOLT_0p73V        (1 << TSI_GENCS_DVOLT_SHIFT)
+#  define TSI_GENCS_DVOLT_0p43V        (2 << TSI_GENCS_DVOLT_SHIFT)
+#  define TSI_GENCS_DVOLT_0p29V        (3 << TSI_GENCS_DVOLT_SHIFT)
+#define TSI_GENCS_REFCHRG_SHIFT        (21)      /* Bits 21-23: Reference Osc charge/discharge value */
+#define TSI_GENCS_REFCHRG_MASK         (7 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_500NA      (0 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_1UA        (1 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_2UA        (2 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_4UA        (3 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_8UA        (4 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_16UA       (5 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_32UA       (6 << TSI_GENCS_REFCHRG_SHIFT)
+#  define TSI_GENCS_REFCHRG_64UA       (7 << TSI_GENCS_REFCHRG_SHIFT)
+#define TSI_GENCS_MODE_SHIFT           (24)      /* Bits 24-27: Analog mode setup and status bits */
+#define TSI_GENCS_MODE_MASK            (15 << TSI_GENCS_MODE_SHIFT)
+#  define TSI_GENCS_MODE_CAPSENSING    (0 << TSI_GENCS_MODE_SHIFT)
+#  define TSI_GENCS_MODE_SGTSHD_NOFREQ (4 << TSI_GENCS_MODE_SHIFT)
+#  define TSI_GENCS_MODE_SGTSHD_FRQLIM (8 << TSI_GENCS_MODE_SHIFT)
+#  define TSI_GENCS_MODE_AUTODETECT    (12 << TSI_GENCS_MODE_SHIFT)
+#define TSI_GENCS_ESOR                 (1 << 28) /* Bit 28: End/Out-of-range interrupt selection */
+                                                 /* Bits 29-30: Reserved */
+#define TSI_GENCS_OUTRFG               (1 << 31) /* Bit 31: Out of range flag */
+
+/* SCAN control register */
+
+#define TSI_DATA_TSICNT_SHIFT          (0)       /* Bits 0-15: TSI Conversion counter value */
+#define TSI_DATA_TSICNT_MASK           (0xffff << TSI_DATA_TSICNT_SHIFT)
+                                                 /* Bits 16-21: Reserved */
+#define TSI_DATA_SWTS                  (1 << 22) /* Bit 22: Software trigger start */
+#define TSI_DATA_DMAEN                 (1 << 23) /* Bit 23: DMA Transfer enabled */
+                                                 /* Bits 24-27: Reserved */
+#define TSI_DATA_TSICH_SHIFT           (28)      /* Bits 28-31: Current channel to be measured */
+#define TSI_DATA_TSICH_MASK            (15 << TSI_DATA_TSICH_SHIFT)
+#  define TSI_DATA_TSICH(n)            (n << TSI_DATA_TSICH_SHIFT)  /* Channel to measure, n=0..15 */
+
+/* Channel n threshold register */
+
+#define TSI_THRESHLD_HTHH_SHIFT        (0)       /* Bits 0-15: High threshold value */
+#define TSI_THRESHLD_HTHH_MASK         (0xffff << TSI_THRESHLD_HTHH_SHIFT)
+#define TSI_THRESHLD_LTHH_SHIFT        (16)      /* Bits 16-31: Low threshold value */
+#define TSI_THRESHLD_LTHH_MASK         (0xffff << TSI_THRESHLD_LTHH_SHIFT)
+
+/************************************************************************************
+ * Public Types
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Data
+ ************************************************************************************/
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+#endif /* __ARCH_ARM_SRC_KL_CHIP_KL_TSI_H */
diff --git a/nuttx/configs/freedom-kl25z/include/board.h b/nuttx/configs/freedom-kl25z/include/board.h
index cb42980da..08e9e0afe 100644
--- a/nuttx/configs/freedom-kl25z/include/board.h
+++ b/nuttx/configs/freedom-kl25z/include/board.h
@@ -312,6 +312,20 @@ extern "C" {
 
 void kl_boardinitialize(void);
 
+/************************************************************************************
+ * Name: kl_tsi_initialize
+ *
+ * Description:
+ *   Initialize the TSI hardware and interface for the sliders on board the Freedom
+ *   KL25Z board.  Register a character driver at /dev/tsi that may be used to read
+ *   from each sensor.
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_KL_TSI
+void kl_tsi_initialize(void);
+#endif
+
 #undef EXTERN
 #if defined(__cplusplus)
 }
diff --git a/nuttx/configs/freedom-kl25z/src/Makefile b/nuttx/configs/freedom-kl25z/src/Makefile
index 30333c4cc..68db441bc 100644
--- a/nuttx/configs/freedom-kl25z/src/Makefile
+++ b/nuttx/configs/freedom-kl25z/src/Makefile
@@ -42,6 +42,10 @@ AOBJS = $(ASRCS:.S=$(OBJEXT))
 
 CSRCS = kl_boardinitialize.c 
 
+ifeq ($(CONFIG_KL_TSI),y)
+CSRCS += kl_tsi.c
+endif
+
 ifeq ($(CONFIG_HAVE_CXX),y)
 CSRCS += kl_cxxinitialize.c
 endif
@@ -66,7 +70,7 @@ ifeq ($(CONFIG_WATCHDOG),y)
 CSRCS += kl_watchdog.c
 endif
 
-ifeq ($(CONFIG_NSH_ARCHINIT),y)
+ifeq ($(CONFIG_NSH_LIBRARY),y)
 CSRCS += kl_nsh.c
 endif
 
diff --git a/nuttx/configs/freedom-kl25z/src/kl_boardinitialize.c b/nuttx/configs/freedom-kl25z/src/kl_boardinitialize.c
index 562302237..eff2873b1 100644
--- a/nuttx/configs/freedom-kl25z/src/kl_boardinitialize.c
+++ b/nuttx/configs/freedom-kl25z/src/kl_boardinitialize.c
@@ -100,3 +100,29 @@ void kl_boardinitialize(void)
   kl_ledinit();
 #endif
 }
+/****************************************************************************
+ * Name: board_initialize
+ *
+ * Description:
+ *   If CONFIG_BOARD_INITIALIZE is selected, then an additional
+ *   initialization call will be performed in the boot-up sequence to a
+ *   function called board_initialize().  board_initialize() will be
+ *   called immediately after up_intitialize() is called and just before the
+ *   initial application is started.  This additional initialization phase
+ *   may be used, for example, to initialize board-specific device drivers.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_BOARD_INITIALIZE
+void board_initialize(void)
+{
+  /* Perform NSH initialization here instead of from the NSH.  This
+   * alternative NSH initialization is necessary when NSH is ran in user-space
+   * but the initialization function must run in kernel space.
+   */
+
+#if defined(CONFIG_NSH_LIBRARY) && !defined(CONFIG_NSH_ARCHINIT)
+  (void)nsh_archinitialize();
+#endif
+}
+#endif
diff --git a/nuttx/configs/freedom-kl25z/src/kl_nsh.c b/nuttx/configs/freedom-kl25z/src/kl_nsh.c
new file mode 100644
index 000000000..3b9187466
--- /dev/null
+++ b/nuttx/configs/freedom-kl25z/src/kl_nsh.c
@@ -0,0 +1,92 @@
+/****************************************************************************
+ * config/stm32f4discovery/src/kl_nsh.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdio.h>
+
+#ifdef CONFIG_NSH_LIBRARY
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+
+/* Debug ********************************************************************/
+
+#ifdef CONFIG_CPP_HAVE_VARARGS
+#  if defined(CONFIG_DEBUG) || !defined(CONFIG_NSH_ARCHINIT)
+#    define message(...) lowsyslog(__VA_ARGS__)
+#  else
+#    define message(...) printf(__VA_ARGS__)
+#  endif
+#else
+#  if defined(CONFIG_DEBUG) || !defined(CONFIG_NSH_ARCHINIT)
+#    define message lowsyslog
+#  else
+#    define message printf
+#  endif
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nsh_archinitialize
+ *
+ * Description:
+ *   Perform architecture specific initialization
+ *
+ *   CONFIG_NSH_ARCHINIT=y :
+ *     Called from the NSH library
+ *
+ *   CONFIG_BOARD_INITIALIZE=y, CONFIG_NSH_LIBRARY=y, &&
+ *   CONFIG_NSH_ARCHINIT=n :
+ *     Called from board_initialize().
+ *
+ ****************************************************************************/
+
+int nsh_archinitialize(void)
+{
+  return OK;
+}
+
+#endif /* CONFIG_NSH_LIBRARY */
diff --git a/nuttx/configs/freedom-kl25z/src/kl_tsi.c b/nuttx/configs/freedom-kl25z/src/kl_tsi.c
new file mode 100644
index 000000000..18afb4580
--- /dev/null
+++ b/nuttx/configs/freedom-kl25z/src/kl_tsi.c
@@ -0,0 +1,261 @@
+/****************************************************************************
+ * configs/freedom-kl25z/src/kl_tsi.c
+ *
+ *   Copyright (C) 2013 Alan Carvalho de Assis
+ *   Author: Alan Carvalho de Assis <acassis@gmail.com>
+ *           with adaptions from Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Reference: https://community.freescale.com/community/
+ *            the-embedded-beat/blog/2012/10/15/
+ *            using-the-touch-interface-on-the-freescale-freedom-development-platform
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdint.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/fs/fs.h>
+
+#include "up_arch.h"
+#include "kl_gpio.h"
+#include "chip/kl_tsi.h"
+#include "chip/kl_pinmux.h"
+#include "chip/kl_sim.h"
+
+#ifdef CONFIG_KL_TSI
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* The touchpad on the Freedom KL25Z board connects to the MCU via:
+ *
+ *   PTB16 TWI0_CH9
+ *   PTB17 TSI0_CH10
+ */
+
+#define NSENSORS 2
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void    tsi_calibrate(void);
+static ssize_t tsi_read(FAR struct file *filep, FAR char *buffer, size_t buflen);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static uint16_t g_defcap[NSENSORS];    /* Default capacitance for each sensor */
+static uint16_t g_currdelta = 0;       /* Current delta for the current button */
+static uint8_t  g_channel = 0;         /* Current g_channel */
+
+/* Channel assigned to each sensor */
+
+static uint8_t const g_chsensor[NSENSORS] = { 9, 10 };
+
+/* Character driver operations */
+
+static const struct file_operations tsi_ops =
+{
+  0,           /* open */
+  0,           /* close */
+  tsi_read,    /* read */
+  0,           /* write */
+  0,           /* seek */
+  0,           /* ioctl */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: tsi_calibrate
+ ****************************************************************************/
+
+static void tsi_calibrate(void)
+{
+  uint32_t regval;
+  int i;
+
+  for (i = 0; i < NSENSORS; i++)
+    {
+      /* Clear end of scan flag */
+
+      regval  = getreg32(KL_TSI_GENCS);
+      regval |= TSI_GENCS_EOSF;
+      putreg32(regval, KL_TSI_GENCS);
+
+      /* Scan the next electrode */
+
+      regval = TSI_DATA_TSICH(g_chsensor[i]);
+      putreg32(regval, KL_TSI_DATA);
+
+      regval |= TSI_DATA_SWTS;
+      putreg32(regval, KL_TSI_DATA);
+
+      /* Wait until the conversion is done */
+
+      while (!(getreg32(KL_TSI_GENCS) & TSI_GENCS_EOSF));
+
+      g_defcap[i] = getreg32(KL_TSI_DATA) & TSI_DATA_TSICNT_MASK;
+      ivdbg("Sensor %d = %d\n", i+1, g_defcap[i]);
+    }
+}
+
+/****************************************************************************
+ * Name: tsi_read
+ ****************************************************************************/
+
+static ssize_t tsi_read(FAR struct file *filep, FAR char *buf, size_t buflen)
+{
+  static int deltacap = 0;
+  uint32_t regval;
+
+  if (buf == NULL || buflen < 1)
+    {
+      /* Well... nothing to do */
+
+      return -EINVAL;
+    }
+
+  deltacap = 0;
+
+  /* Clear end of scan flag */
+
+  regval  = getreg32(KL_TSI_GENCS);
+  regval |= TSI_GENCS_EOSF;
+  putreg32(regval, KL_TSI_GENCS);
+
+  /* Scan the next electrode */
+
+  regval = TSI_DATA_TSICH(g_chsensor[g_channel]);
+  putreg32(regval, KL_TSI_DATA);
+  
+  regval |= TSI_DATA_SWTS;
+  putreg32(regval, KL_TSI_DATA);
+
+  /* Wait until the conversion is done*/
+
+  while (!(getreg32(KL_TSI_GENCS) & TSI_GENCS_EOSF));
+
+  /* Compute delta using calibration reference counts */
+
+  deltacap  = getreg32(KL_TSI_DATA) & TSI_DATA_TSICNT_MASK;
+  deltacap -= g_defcap[g_channel];
+
+  if (deltacap < 0)
+    {
+      deltacap = 0;
+    }
+
+  g_currdelta = (uint16_t)deltacap;
+
+  ivdbg("Delta for g_channel %d = %d\n", g_channel, g_currdelta);
+
+  buf[0] = g_currdelta & 0xff;
+  buf[1] = (g_currdelta & 0xff00) >> 8;
+  buf[2] = g_channel;
+
+  /* Increment the channel index to sample the next sensor on the next timer
+   * that read() is called.
+   */
+
+  g_channel++;
+  if (g_channel >= NSENSORS)
+    {
+      g_channel = 0;
+    }
+
+  return 3;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: kl_tsi_initialize
+ *
+ * Description:
+ *   Initialize the TSI hardware and interface for the sliders on board the
+ *   Freedom KL25Z board.  Register a character driver at /dev/tsi that may
+ *   be used to read from each sensor.
+ *
+ ****************************************************************************/
+
+void kl_tsi_initialize(void)
+{
+  uint32_t regval;
+
+  /* Enable access to the TSI module */
+
+  regval = getreg32(KL_SIM_SCGC5);
+  regval |= SIM_SCGC5_TSI;
+  putreg32(regval, KL_SIM_SCGC5);
+
+  /* Configure PINs used on TSI */
+
+  kl_configgpio(PIN_TSI0_CH9);
+  kl_configgpio(PIN_TSI0_CH10);
+
+  /* Configure TSI parameter */
+
+  regval = getreg32(KL_TSI_GENCS);
+  regval |= TSI_GENCS_MODE_CAPSENSING | TSI_GENCS_REFCHRG_8UA |
+            TSI_GENCS_DVOLT_1p03V | TSI_GENCS_EXTCHRG_64A |
+            TSI_GENCS_PS_DIV16 | TSI_GENCS_NSCN_TIMES(12) | TSI_GENCS_STPE;
+  putreg32(regval, KL_TSI_GENCS);
+
+  /* Only after setting TSI we should enable it */
+
+  regval  = getreg32(KL_TSI_GENCS);
+  regval |= TSI_GENCS_TSIEN;
+  putreg32(regval, KL_TSI_GENCS);
+
+  /* Calibrate it before to use */
+
+  tsi_calibrate();
+
+  /* And finally register the TSI character driver */
+
+  (void)register_driver("/dev/tsi", &tsi_ops, 0444, NULL);
+}
+
+#endif /* CONFIG_KL_TSI */