Add generic EEPROM I2C device driver

cpukit/dev/Makefile.am

@@ -6,6 +6,7 @@ include_dev_HEADERS =
 
 include_dev_i2cdir = $(includedir)/dev/i2c
 include_dev_i2c_HEADERS =
+include_dev_i2c_HEADERS += include/dev/i2c/eeprom.h
 include_dev_i2c_HEADERS += include/dev/i2c/i2c.h
 
 include_linuxdir = $(includedir)/linux
@@ -16,6 +17,7 @@ include_linux_HEADERS += include/linux/i2c-dev.h
 noinst_LIBRARIES = libdev.a
 
 libdev_a_SOURCES =
+libdev_a_SOURCES += i2c/eeprom.c
 libdev_a_SOURCES += i2c/i2c-bus.c
 libdev_a_SOURCES += i2c/i2c-dev.c
 

cpukit/dev/i2c/eeprom.c

@@ -0,0 +1,260 @@
+/**
+ * @file
+ *
+ * @brief EEPROM Driver Implementation
+ *
+ * @ingroup I2CEEPROM
+ */
+
+/*
+ * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include <dev/i2c/eeprom.h>
+
+#include <string.h>
+
+#define EEPROM_MAX_ADDRESS_BYTES 4
+
+#define EEPROM_MAX_PAGE_SIZE 128
+
+typedef struct {
+  i2c_dev base;
+  uint16_t address_bytes;
+  uint16_t page_size;
+  uint32_t size;
+  uint16_t i2c_address_mask;
+  uint16_t i2c_address_shift;
+  rtems_interval program_timeout;
+} eeprom;
+
+static uint16_t eeprom_i2c_addr(eeprom *dev, uint32_t off)
+{
+  return dev->base.address
+    | ((off >> dev->i2c_address_shift) & dev->i2c_address_mask);
+}
+
+static ssize_t eeprom_read(
+  i2c_dev *base,
+  void *buf,
+  size_t n,
+  off_t offset
+)
+{
+  eeprom *dev = (eeprom *) base;
+  off_t avail = dev->size - offset;
+  uint32_t off = (uint32_t) offset;
+  uint8_t *in = buf;
+  size_t todo;
+
+  if (avail <= 0) {
+    return 0;
+  }
+
+  if (n > avail) {
+    n = (size_t) avail;
+  }
+
+  todo = n;
+
+  while (todo > 0) {
+    uint16_t i2c_addr = eeprom_i2c_addr(dev, off);
+
+    /*
+     * Limit the transfer size so that it can be stored in 8-bits.  This may
+     * help some bus controllers.
+     */
+    uint16_t cur = (uint16_t) (todo < 255 ?  todo : 255);
+
+    uint8_t addr[EEPROM_MAX_ADDRESS_BYTES] = {
+      (uint8_t) off,
+      (uint8_t) (off >> 8),
+      (uint8_t) (off >> 16),
+      (uint8_t) (off >> 24)
+    };
+    i2c_msg msgs[2] = {
+      {
+        .addr = i2c_addr,
+        .flags = 0,
+        .len = dev->address_bytes,
+        .buf = &addr[0]
+      }, {
+        .addr = i2c_addr,
+        .flags = I2C_M_RD,
+        .buf = in,
+        .len = cur
+      }
+    };
+    int err;
+
+    err = i2c_bus_transfer(dev->base.bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs));
+    if (err != 0) {
+      return err;
+    }
+
+    todo -= cur;
+    off += cur;
+    in += cur;
+  }
+
+  return (ssize_t) n;
+}
+
+static ssize_t eeprom_write(
+  i2c_dev *base,
+  const void *buf,
+  size_t n,
+  off_t offset
+)
+{
+  eeprom *dev = (eeprom *) base;
+  off_t avail = dev->size - offset;
+  uint32_t off = (uint32_t) offset;
+  const uint8_t *out = buf;
+  size_t todo;
+
+  if (avail <= 0) {
+    return 0;
+  }
+
+  if (n > avail) {
+    n = (size_t) avail;
+  }
+
+  todo = n;
+
+  while (todo > 0) {
+    uint16_t i2c_addr = eeprom_i2c_addr(dev, off);
+    uint16_t rem = dev->page_size - (off & (dev->page_size - 1));
+    uint16_t cur = (uint16_t) (todo < rem ? todo : rem);
+    uint8_t addr[EEPROM_MAX_ADDRESS_BYTES] = {
+      (uint8_t) off,
+      (uint8_t) (off >> 8),
+      (uint8_t) (off >> 16),
+      (uint8_t) (off >> 24)
+    };
+    i2c_msg msgs[2] = {
+      {
+        .addr = i2c_addr,
+        .flags = 0,
+        .len = dev->address_bytes,
+        .buf = &addr[0]
+      }, {
+        .addr = i2c_addr,
+        .flags = I2C_M_NOSTART,
+        .buf = RTEMS_DECONST(uint8_t *, out),
+        .len = cur
+      }
+    };
+    uint8_t in[EEPROM_MAX_PAGE_SIZE];
+    int err;
+    ssize_t m;
+    rtems_interval timeout;
+
+    err = i2c_bus_transfer(dev->base.bus, &msgs[0], RTEMS_ARRAY_SIZE(msgs));
+    if (err != 0) {
+      return err;
+    }
+
+    timeout = rtems_clock_tick_later(dev->program_timeout);
+
+    do {
+      m = eeprom_read(&dev->base, &in[0], cur, off);
+    } while (m != cur && rtems_clock_tick_before(timeout));
+
+    if (m != cur) {
+      return -ETIMEDOUT;
+    }
+
+    if (memcmp(&in[0], &out[0], cur) != 0) {
+      return -EIO;
+    }
+
+    todo -= cur;
+    off += cur;
+    out += cur;
+  }
+
+  return (ssize_t) n;
+}
+
+static off_t eeprom_get_size(i2c_dev *base)
+{
+  eeprom *dev = (eeprom *) base;
+
+  return dev->size;
+}
+
+static blksize_t eeprom_get_block_size(i2c_dev *base)
+{
+  eeprom *dev = (eeprom *) base;
+
+  return dev->page_size;
+}
+
+int i2c_dev_register_eeprom(
+  const char *bus_path,
+  const char *dev_path,
+  uint16_t i2c_address,
+  uint16_t address_bytes,
+  uint16_t page_size_in_bytes,
+  uint32_t size_in_bytes,
+  uint32_t program_timeout_in_ms
+)
+{
+  uint32_t extra_address;
+  eeprom *dev;
+
+  if (address_bytes > EEPROM_MAX_ADDRESS_BYTES) {
+    rtems_set_errno_and_return_minus_one(ERANGE);
+  }
+
+  if (page_size_in_bytes > EEPROM_MAX_PAGE_SIZE) {
+    page_size_in_bytes = EEPROM_MAX_PAGE_SIZE;
+  }
+
+  extra_address = size_in_bytes >> (8 * address_bytes);
+  if (extra_address != 0 && (extra_address & (extra_address - 1)) != 0) {
+    rtems_set_errno_and_return_minus_one(EINVAL);
+  }
+
+  if (program_timeout_in_ms == 0) {
+    program_timeout_in_ms = 1000;
+  }
+
+  dev = (eeprom *)
+    i2c_dev_alloc_and_init(sizeof(*dev), bus_path, i2c_address);
+  if (dev == NULL) {
+    return -1;
+  }
+
+  dev->base.read = eeprom_read;
+  dev->base.write = eeprom_write;
+  dev->base.get_size = eeprom_get_size;
+  dev->base.get_block_size = eeprom_get_block_size;
+  dev->address_bytes = address_bytes;
+  dev->page_size = page_size_in_bytes;
+  dev->size = size_in_bytes;
+  dev->program_timeout = RTEMS_MILLISECONDS_TO_TICKS(program_timeout_in_ms);
+
+  if (extra_address != 0) {
+    dev->i2c_address_mask = extra_address - 1;
+    dev->i2c_address_shift = (uint16_t) (8 * address_bytes);
+  }
+
+  return i2c_dev_register(&dev->base, dev_path);
+}

cpukit/dev/include/dev/i2c/eeprom.h

@@ -0,0 +1,58 @@
+/**
+ * @file
+ *
+ * @brief EEPROM Driver API
+ *
+ * @ingroup I2CEEPROM
+ */
+
+/*
+ * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#ifndef _DEV_I2C_EEPROM_H
+#define _DEV_I2C_EEPROM_H
+
+#include <dev/i2c/i2c.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @defgroup I2CEEPROM EEPROM Driver
+ *
+ * @ingroup I2CDevice
+ *
+ * @brief Driver for EEPROM device.
+ *
+ * @{
+ */
+
+int i2c_dev_register_eeprom(
+  const char *bus_path,
+  const char *dev_path,
+  uint16_t i2c_address,
+  uint16_t address_bytes,
+  uint16_t page_size_in_bytes,
+  uint32_t size_in_bytes,
+  uint32_t program_timeout_in_ms
+);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* _DEV_I2C_EEPROM_H */

cpukit/dev/preinstall.am

@@ -23,6 +23,10 @@ $(PROJECT_INCLUDE)/dev/i2c/$(dirstamp):
 	@: > $(PROJECT_INCLUDE)/dev/i2c/$(dirstamp)
 PREINSTALL_DIRS += $(PROJECT_INCLUDE)/dev/i2c/$(dirstamp)
 
+$(PROJECT_INCLUDE)/dev/i2c/eeprom.h: include/dev/i2c/eeprom.h $(PROJECT_INCLUDE)/dev/i2c/$(dirstamp)
+	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/dev/i2c/eeprom.h
+PREINSTALL_FILES += $(PROJECT_INCLUDE)/dev/i2c/eeprom.h
+
 $(PROJECT_INCLUDE)/dev/i2c/i2c.h: include/dev/i2c/i2c.h $(PROJECT_INCLUDE)/dev/i2c/$(dirstamp)
 	$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/dev/i2c/i2c.h
 PREINSTALL_FILES += $(PROJECT_INCLUDE)/dev/i2c/i2c.h