drivers/i2c: Move wrapper that implements I2C_WRITEREAD using I2C_transfer from pc9555.c to a new, comon i2c directory

ChangeLog

@@ -11369,3 +11369,6 @@
 	  ioexpander and not the I2C address.  From Stefan Kolb (2016-01-26).
 	* drivers/ioexpander/pca9555: Convert to use I2C_TRANSFER vs. I2C_WRITEREAD,
 	  the former is thread safe while the latter is deprecated (2016-01-26).
+	* drivers/i2c/i2c_writeread.c:  Create a wrapper that uses I2C_TRANSFER
+	  to implement I2C_WRITEREAD functionalit (2016-01-26).
+

drivers/Kconfig

@@ -271,38 +271,8 @@ menuconfig I2C
 		See include/nuttx/i2c.h for further I2C driver information.
 
 if I2C
-
+source drivers/i2c/Kconfig
-config I2C_SLAVE
+endif
-	bool "I2C Slave"
-	default n
-
-config I2C_TRANSFER
-	bool "Support the I2C transfer() method"
-	default n
-
-config I2C_WRITEREAD
-	bool "Support the I2C writeread() method"
-	default n
-
-config I2C_POLLED
-	bool "Polled I2C (no interrupts)"
-	default n
-
-config I2C_TRACE
-	bool "Enable I2C trace debug"
-	default n
-
-config I2C_NTRACE
-	int "Number of I2C trace records"
-	default 32
-	depends on I2C_TRACE
-
-config I2C_RESET
-	bool "Support up_i2creset"
-	default n
-	depends on ARCH_HAVE_I2CRESET
-
-endif # I2C
 
 menuconfig SPI
 	bool "SPI Driver Support"

drivers/Makefile

@@ -52,6 +52,7 @@ VPATH = .
 include analog$(DELIM)Make.defs
 include audio$(DELIM)Make.defs
 include bch$(DELIM)Make.defs
+include i2c$(DELIM)Make.defs
 include input$(DELIM)Make.defs
 include ioexpander$(DELIM)Make.defs
 include lcd$(DELIM)Make.defs

drivers/README.txt

@@ -68,6 +68,9 @@ eeprom/
   interface but instead use the simple character interface provided by
   the EEPROM drivers.
 
+i2c/
+  I2C drivers and support logic.  See include/nuttx/i2c.h
+
 input/
   This directory holds implementations of human input device (HID)
   drivers.  This includes such things as mouse, touchscreen, joystick,
@@ -144,7 +147,7 @@ serial/
   the NuttX system console.  See also include/nuttx/serial/serial.h
 
 spi/
-  SPI drivers.  See include/nuttx/spi.h
+  SPI drivers and support logic.  See include/nuttx/spi/spi.h
 
 syslog/
   System logging devices. See include/syslog.h and include/nuttx/syslog/syslog.h

drivers/i2c/Kconfig

@@ -0,0 +1,38 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+if I2C
+
+config I2C_SLAVE
+	bool "I2C Slave"
+	default n
+
+config I2C_TRANSFER
+	bool "Support the I2C transfer() method"
+	default n
+
+config I2C_WRITEREAD
+	bool "Support the I2C writeread() method"
+	default n
+
+config I2C_POLLED
+	bool "Polled I2C (no interrupts)"
+	default n
+
+config I2C_TRACE
+	bool "Enable I2C trace debug"
+	default n
+
+config I2C_NTRACE
+	int "Number of I2C trace records"
+	default 32
+	depends on I2C_TRACE
+
+config I2C_RESET
+	bool "Support up_i2creset"
+	default n
+	depends on ARCH_HAVE_I2CRESET
+
+endif # I2C

drivers/i2c/Make.defs

@@ -0,0 +1,50 @@
+############################################################################
+# drivers/i2c/Make.defs
+#
+#   Copyright (C) 2016 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.
+#
+############################################################################
+
+# Don't build anything if there is no I2C support
+
+ifeq ($(CONFIG_I2C),y)
+
+ifeq ($(CONFIG_I2C_TRANSFER),y)
+  CSRCS += i2c_writeread.c
+endif
+
+# Include I2C device driver build support
+
+DEPPATH += --dep-path i2c
+VPATH += :i2c
+CFLAGS += ${shell $(INCDIR) $(INCDIROPT) "$(CC)" $(TOPDIR)$(DELIM)drivers$(DELIM)i2c}
+endif
+

drivers/i2c/i2c_writeread.c

@@ -0,0 +1,103 @@
+/****************************************************************************
+ * drivers/i2c/i2c_writeread.c
+ *
+ *   Copyright (C) 2016 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 <assert.h>
+
+#include <nuttx/i2c.h>
+
+#if defined(CONFIG_I2C_TRANSFER)
+
+/****************************************************************************
+ * Name: pca9555_writeread
+ *
+ * Description:
+ *   Write to then read from the I2C device.
+ *
+ ****************************************************************************/
+
+int i2c_writeread(FAR struct i2c_dev_s *dev, FAR const struct i2c_config_s *config,
+                  FAR const uint8_t *wbuffer, int wbuflen,
+                  FAR uint8_t *rbuffer, int rbuflen)
+{
+  struct i2c_msg_s msg[2];
+  unsigned int flags;
+
+  /* 7- or 10-bit address? */
+
+  DEBUGASSERT(config->addrlen == 10 || config->addrlen == 7);
+  flags = (config->addrlen == 10) ? I2C_M_TEN : 0;
+
+  /* Format two messages: The first is a write */
+
+  msg[0].addr   = config->address;
+  msg[0].flags  = flags;
+  msg[0].buffer = (FAR uint8_t *)wbuffer;  /* Override const */
+  msg[0].length = wbuflen;
+
+  /* The second is either a read (rbuflen > 0) or a write (rbuflen < 0) with
+   * no restart.
+   */
+
+  if (rbuflen > 0)
+    {
+      msg[1].flags = (flags | I2C_M_READ);
+    }
+  else
+    {
+      msg[1].flags = (flags | I2C_M_NORESTART);
+      rbuflen = -rbuflen;
+    }
+
+  msg[1].addr   = config->address;
+  msg[1].buffer = rbuffer;
+  msg[1].length = rbuflen;
+
+  /* Then perform the transfer
+   *
+   * REVISIT:  The following two operations must become atomic in order to
+   * assure thread safety.
+   */
+
+  I2C_SETFREQUENCY(dev, config->frequency);
+  return I2C_TRANSFER(dev, msg, 2);
+}
+
+#endif /* CONFIG_I2C_TRANSFER */

drivers/ioexpander/pca9555.c

@@ -137,41 +137,19 @@ static const struct ioexpander_ops_s g_pca9555_ops =
  *
  ****************************************************************************/
 
-static int pca9555_writeread(FAR struct pca9555_dev_s *pca,
+static inline int pca9555_writeread(FAR struct pca9555_dev_s *pca,
-                             FAR const uint8_t *wbuffer, int wbuflen,
+                                    FAR const uint8_t *wbuffer, int wbuflen,
-                             FAR uint8_t *rbuffer, int rbuflen)
+                                    FAR uint8_t *rbuffer, int rbuflen)
 {
-  struct i2c_msg_s msg[2];
+  struct i2c_config_s config;
 
-  /* Format two messages: The first is a write */
+  /* Set up the configuration and perform the write-read operation */
 
-  msg[0].addr   = pca->config->address;
+  config.frequency = pca->config->frequency;
-  msg[0].flags  = 0;
+  config.address   = pca->config->address;
-  msg[0].buffer = (uint8_t *)wbuffer;  /* Override const */
+  config.addrlen   = 7;
-  msg[0].length = wbuflen;
 
-  /* The second is either a read (rbuflen > 0) or a write (rbuflen < 0) with
+  return i2c_writeread(pca->i2c, &config, wbuffer, wbuflen, rbuffer, rbuflen);
-   * no restart.
-   */
-
-  if (rbuflen > 0)
-    {
-      msg[1].flags = I2C_M_READ;
-    }
-  else
-    {
-      msg[1].flags = I2C_M_NORESTART;
-      rbuflen = -rbuflen;
-    }
-
-  msg[1].addr   = pca->config->address;
-  msg[1].buffer = rbuffer;
-  msg[1].length = rbuflen;
-
-  /* Then perform the transfer */
-
-  I2C_SETFREQUENCY(pca->i2c, pca->config->frequency);
-  return I2C_TRANSFER(pca->i2c, msg, 2);
 }
 
 /****************************************************************************

drivers/spi/Kconfig

@@ -80,5 +80,5 @@ config SPI_BITBANG_VARWIDTH
 		Enable support for a variable data width transfers.  Default: 8-bit
 		only.
 
-endif
+endif # SPI_BITBANG
-endif
+endif # SPI

include/nuttx/i2c.h

@@ -1,7 +1,7 @@
 /****************************************************************************
  * include/nuttx/i2c.h
  *
- *   Copyright(C) 2009-2012 Gregory Nutt. All rights reserved.
+ *   Copyright(C) 2009-2012, 2016 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -251,23 +251,36 @@ struct i2c_ops_s
   uint32_t (*setfrequency)(FAR struct i2c_dev_s *dev, uint32_t frequency);
   int    (*setaddress)(FAR struct i2c_dev_s *dev, int addr, int nbits);
   int    (*write)(FAR struct i2c_dev_s *dev, const uint8_t *buffer,
-                  int buflen);
+           int buflen);
   int    (*read)(FAR struct i2c_dev_s *dev, uint8_t *buffer, int buflen);
 #ifdef CONFIG_I2C_WRITEREAD
-  int    (*writeread)(FAR struct i2c_dev_s *inst, const uint8_t *wbuffer,
+  int    (*writeread)(FAR struct i2c_dev_s *dev,
-                      int wbuflen, uint8_t *rbuffer, int rbuflen);
+           FAR const uint8_t *wbuffer, int wbuflen,
+           FAR uint8_t *rbuffer, int rbuflen);
 #endif
 #ifdef CONFIG_I2C_TRANSFER
   int    (*transfer)(FAR struct i2c_dev_s *dev, FAR struct i2c_msg_s *msgs,
-                     int count);
+           int count);
 #endif
 #ifdef CONFIG_I2C_SLAVE
   int    (*setownaddress)(FAR struct i2c_dev_s *dev, int addr, int nbits);
   int    (*registercallback)(FAR struct i2c_dev_s *dev,
-                             int (*callback)(FAR void *arg), FAR void *arg);
+           int (*callback)(FAR void *arg), FAR void *arg);
 #endif
 };
 
+/* This structure contains the full state of I2C as needed for a specific
+ * transfer.  It is passed to I2C methods so that I2C transfer may be
+ * performed in a thread safe manner.
+ */
+
+struct i2c_config_s
+{
+  uint32_t frequency;              /* I2C frequency */
+  uint16_t address;                /* I2C address (7 or 10 bit) */
+  uint8_t  addrlen;                /* I2C address length (7 or 10 bits) */
+};
+
 /* I2C transaction segment beginning with a START.  A number of these can
  * be transferred together to form an arbitrary sequence of write/read transfer
  * to an I2C slave device.
@@ -352,6 +365,20 @@ int up_i2cuninitialize(FAR struct i2c_dev_s *dev);
 int up_i2creset(FAR struct i2c_dev_s *dev);
 #endif
 
+/************************************************************************************
+ * Name: i2c_writeread
+ *
+ * Description:
+ *   Write to then read from the I2C device.
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_I2C_TRANSFER
+int i2c_writeread(FAR struct i2c_dev_s *dev, FAR const struct i2c_config_s *config,
+                  FAR const uint8_t *wbuffer, int wbuflen,
+                  FAR uint8_t *rbuffer, int rbuflen);
+#endif
+
 #undef EXTERN
 #if defined(__cplusplus)
 }