drivers/at24cxxx: at24cxxx EEPROM driver

drivers/Makefile.dep

@@ -36,8 +36,14 @@ ifneq (,$(filter at,$(USEMODULE)))
   USEMODULE += isrpipe_read_timeout
 endif
 
-ifneq (,$(filter at24mac,$(USEMODULE)))
+ifneq (,$(filter at24c%,$(USEMODULE)))
   FEATURES_REQUIRED += periph_i2c
+  USEMODULE += xtimer
+  USEMODULE += at24cxxx
+endif
+
+ifneq (,$(filter at24mac,$(USEMODULE)))
+  USEMODULE += at24cxxx
 endif
 
 ifneq (,$(filter at30tse75x,$(USEMODULE)))

drivers/Makefile.include

@@ -20,6 +20,10 @@ ifneq (,$(filter apa102,$(USEMODULE)))
   USEMODULE_INCLUDES += $(RIOTBASE)/drivers/apa102/include
 endif
 
+ifneq (,$(filter at24cxxx,$(USEMODULE)))
+  USEMODULE_INCLUDES += $(RIOTBASE)/drivers/at24cxxx/include
+endif
+
 ifneq (,$(filter at24mac,$(USEMODULE)))
   USEMODULE_INCLUDES += $(RIOTBASE)/drivers/at24mac/include
 endif

drivers/at24cxxx/Makefile

@@ -0,0 +1 @@
+include $(RIOTBASE)/Makefile.base

drivers/at24cxxx/at24cxxx.c

@@ -0,0 +1,288 @@
+/*
+ * Copyright (C) 2019 Otto-von-Guericke-Universität Magdeburg
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     drivers_at24cxxx
+ * @{
+ *
+ * @file
+ * @brief       Device driver implementation for at24cxxx EEPROM units.
+ *
+ * @author      Fabian Hüßler <fabian.huessler@ovgu.de>
+ * @}
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+
+#define ENABLE_DEBUG  (0)
+#include "debug.h"
+#include "assert.h"
+#include "xtimer.h"
+
+#include "at24cxxx_defines.h"
+#include "at24cxxx.h"
+
+#ifndef MIN
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+#endif
+
+/**
+ * @brief Calculate x mod y, if y is a power of 2
+ */
+#define MOD_POW2(x, y) ((x) & ((y) - 1))
+
+/**
+ * @brief I2C bus number shortcut
+ */
+#define DEV_I2C_BUS                     (dev->params.i2c)
+/**
+ * @brief Pin wp shortcut
+ */
+#define DEV_PIN_WP                      (dev->params.pin_wp)
+/**
+ * @brief EEPROM size shortcut
+ */
+#define DEV_EEPROM_SIZE                 (dev->params.eeprom_size)
+/**
+ * @brief I2C device address shortcut
+ */
+#define DEV_I2C_ADDR                    (dev->params.dev_addr)
+/**
+ * @brief Page size shortcut
+ */
+#define DEV_PAGE_SIZE                   (dev->params.page_size)
+/**
+ * @brief Max polls shortcut
+ */
+#define DEV_MAX_POLLS                   (dev->params.max_polls)
+
+#ifndef AT24CXXX_SET_BUF_SIZE
+/**
+ * @brief  Adjust to configure buffer size
+ */
+#define AT24CXXX_SET_BUF_SIZE           (32U)
+#endif
+
+static
+int _read(const at24cxxx_t *dev, uint32_t pos, void *data, size_t len)
+{
+    int check;
+    uint8_t polls = DEV_MAX_POLLS;
+    uint8_t dev_addr;
+    uint8_t flags = 0;
+
+    if (DEV_EEPROM_SIZE > 2048) {
+        /* 2 bytes word address length if more than 11 bits are
+           used for addressing */
+        /* append page address bits to device address (if any) */
+        dev_addr  = (DEV_I2C_ADDR | ((pos & 0xFF0000) >> 16));
+        pos &= 0xFFFF;
+        flags = I2C_REG16;
+    }
+    else {
+        /* append page address bits to device address (if any) */
+        dev_addr = (DEV_I2C_ADDR | ((pos & 0xFF00) >> 8));
+        pos &= 0xFF;
+    }
+
+    while (-ENXIO == (check = i2c_read_regs(DEV_I2C_BUS, dev_addr,
+                                            pos, data, len, flags))) {
+        if (--polls == 0) {
+            break;
+        }
+        xtimer_usleep(AT24CXXX_POLL_DELAY_US);
+    }
+    DEBUG("[at24cxxx] i2c_read_regs(): %d; polls: %d\n", check, polls);
+    return check;
+}
+
+static
+int _write(const at24cxxx_t *dev, uint32_t pos, const void *data, size_t len)
+{
+    int check = 0;
+    const uint8_t *cdata = ((const uint8_t *)data);
+
+    while (len) {
+        size_t clen = MIN(len, DEV_PAGE_SIZE - MOD_POW2(pos, DEV_PAGE_SIZE));
+        uint8_t polls = DEV_MAX_POLLS;
+        uint8_t dev_addr;
+        uint16_t _pos;
+        uint8_t flags = 0;
+        if (DEV_EEPROM_SIZE > 2048) {
+            /* 2 bytes word address length if more than 11 bits are
+               used for addressing */
+            /* append page address bits to device address (if any) */
+            dev_addr  = (DEV_I2C_ADDR | ((pos & 0xFF0000) >> 16));
+            _pos = (pos & 0xFFFF);
+            flags = I2C_REG16;
+        }
+        else {
+            /* append page address bits to device address (if any) */
+            dev_addr = (DEV_I2C_ADDR | ((pos & 0xFF00) >> 8));
+            _pos = pos & 0xFF;
+        }
+        while (-ENXIO == (check = i2c_write_regs(DEV_I2C_BUS, dev_addr,
+                                                 _pos, cdata, clen, flags))) {
+            if (--polls == 0) {
+                break;
+            }
+            xtimer_usleep(AT24CXXX_POLL_DELAY_US);
+        }
+        DEBUG("[at24cxxx] i2c_write_regs(): %d; polls: %d\n", check, polls);
+        if (!check) {
+            len -= clen;
+            pos += clen;
+            cdata += clen;
+        }
+        else {
+            break;
+        }
+    }
+    return check;
+}
+
+static
+int _set(const at24cxxx_t *dev, uint32_t pos, uint8_t val, size_t len)
+{
+    int check;
+    uint8_t set_buffer[AT24CXXX_SET_BUF_SIZE];
+
+    memset(set_buffer, val, sizeof(set_buffer));
+    while (len) {
+        size_t clen = MIN(sizeof(set_buffer), len);
+        check = _write(dev, pos, set_buffer, clen);
+        if (!check) {
+            len -= clen;
+            pos += clen;
+        }
+        else {
+            break;
+        }
+    }
+    return check;
+}
+
+int at24cxxx_init(at24cxxx_t *dev, const at24cxxx_params_t *params)
+{
+    if (!dev || !params) {
+        return -EINVAL;
+    }
+    dev->params = *params;
+    if (DEV_PIN_WP != GPIO_UNDEF) {
+        gpio_init(DEV_PIN_WP, GPIO_OUT);
+        at24cxxx_disable_write_protect(dev);
+    }
+    /* Check I2C bus once */
+    if (i2c_acquire(DEV_I2C_BUS)) {
+        return -AT24CXXX_I2C_ERROR;
+    }
+    i2c_release(DEV_I2C_BUS);
+    return AT24CXXX_OK;
+}
+
+int at24cxxx_read_byte(const at24cxxx_t *dev, uint32_t pos, void *dest)
+{
+    if (pos >= DEV_EEPROM_SIZE) {
+        return -ERANGE;
+    }
+
+    i2c_acquire(DEV_I2C_BUS);
+    int check = _read(dev, pos, dest, 1);
+    i2c_release(DEV_I2C_BUS);
+    return check;
+}
+
+int at24cxxx_read(const at24cxxx_t *dev, uint32_t pos, void *data,
+                      size_t len)
+{
+    if (pos + len > DEV_EEPROM_SIZE) {
+        return -ERANGE;
+    }
+
+    int check = AT24CXXX_OK;
+    if (len) {
+        i2c_acquire(DEV_I2C_BUS);
+        check = _read(dev, pos, data, len);
+        i2c_release(DEV_I2C_BUS);
+    }
+    return check;
+}
+
+int at24cxxx_write_byte(const at24cxxx_t *dev, uint32_t pos, uint8_t data)
+{
+    if (pos >= DEV_EEPROM_SIZE) {
+        return -ERANGE;
+    }
+
+    i2c_acquire(DEV_I2C_BUS);
+    int  check = _write(dev, pos, &data, 1);
+    i2c_release(DEV_I2C_BUS);
+    return check;
+}
+
+int at24cxxx_write(const at24cxxx_t *dev, uint32_t pos, const void *data,
+                       size_t len)
+{
+    if (pos + len > DEV_EEPROM_SIZE) {
+        return -ERANGE;
+    }
+
+    int check = AT24CXXX_OK;
+    if (len) {
+        i2c_acquire(DEV_I2C_BUS);
+        check = _write(dev, pos, data, len);
+        i2c_release(DEV_I2C_BUS);
+    }
+    return check;
+}
+
+int at24cxxx_set(const at24cxxx_t *dev, uint32_t pos, uint8_t val,
+                     size_t len)
+{
+    if (pos + len > DEV_EEPROM_SIZE) {
+        return -ERANGE;
+    }
+
+    int check = AT24CXXX_OK;
+    if (len) {
+        i2c_acquire(DEV_I2C_BUS);
+        check = _set(dev, pos, val, len);
+        i2c_release(DEV_I2C_BUS);
+    }
+    return check;
+}
+
+int at24cxxx_clear(const at24cxxx_t *dev, uint32_t pos, size_t len)
+{
+    return at24cxxx_set(dev, pos, AT24CXXX_CLEAR_BYTE, len);
+}
+
+int at24cxxx_erase(const at24cxxx_t *dev)
+{
+    return at24cxxx_clear(dev, 0, DEV_EEPROM_SIZE);
+}
+
+int at24cxxx_enable_write_protect(const at24cxxx_t *dev)
+{
+    if (DEV_PIN_WP == GPIO_UNDEF) {
+        return -ENOTSUP;
+    }
+    gpio_set(DEV_PIN_WP);
+    return AT24CXXX_OK;
+}
+
+int at24cxxx_disable_write_protect(const at24cxxx_t *dev)
+{
+    if (DEV_PIN_WP == GPIO_UNDEF) {
+        return -ENOTSUP;
+    }
+    gpio_clear(DEV_PIN_WP);
+    return AT24CXXX_OK;
+}