drivers/eeprom: Support PE/SE/CE commands

Add support for the page erase (PE), sector erase (SE) and chip erase
(CE) dedicated commands on supported devices.
They can be triggered using the corresponding IOCTL commands
EEPIOC_PAGEERASE, EEPIOC_SECTORERASE and
EEPIOC_CHIPERASE.

On unsupported devices, this is equivalent to writing a full page,
sector, or the entire EEPROM to 0xFF.

Signed-off-by: Antoine Juckler <6445757+ajuckler@users.noreply.github.com>

Author: ajuckler

Documentation/components/drivers/character/eeprom.rst

@@ -165,6 +165,25 @@ The full list of ``ioctl()`` commands can be found in
 
     Set the SPI/I2C bus frequency
 
+- ``EEPIOC_PAGEERASE``
+    *Argument:* ``unsigned long``
+
+    Erase an EEPROM page given its index, a dedicated command is used if
+    supported by the device.
+
+- ``EEPIOC_SECTORERASE``
+    *Argument:* ``unsigned long``
+
+    Erase an EEPROM sector given its index, a dedicated command is used if
+    supported by the device. Equivalent to a page erase on devices without
+    sectors.
+
+- ``EEPIOC_CHIPERASE``
+    *Argument:* ``void``
+
+    Erase the full EEPROM, a dedicated command is used if supported by the
+    device.
+
 File Systems
 ============
 

drivers/eeprom/i2c_xx24xx.c

@@ -327,6 +327,147 @@ static int ee24xx_writepage(FAR struct ee24xx_dev_s *eedev, uint32_t memaddr,
   return I2C_TRANSFER(eedev->i2c, msgs, 2);
 }
 
+/****************************************************************************
+ * Name: ee24xx_eraseall
+ *
+ * Description:
+ *   Erase all data on the device
+ *
+ * Input Parameters:
+ *   eedev - Device structure
+ *
+ ****************************************************************************/
+
+static int ee24xx_eraseall(FAR struct ee24xx_dev_s *eedev)
+{
+  FAR char *buf;
+  off_t     offset;
+  int       ret;
+
+  DEBUGASSERT(eedev);
+
+  if (eedev->readonly)
+    {
+      return -EACCES;
+    }
+
+  buf = kmm_malloc(eedev->pgsize);
+  if (buf == NULL)
+    {
+      ferr("ERROR: Failed to allocate memory for ee24xx eraseall\n");
+      return -ENOMEM;
+    }
+
+  memset(buf, 0xff, eedev->pgsize);
+
+  ret = nxmutex_lock(&eedev->lock);
+  if (ret < 0)
+    {
+      goto free_buffer;
+    }
+
+  for (offset = 0; offset < eedev->size; offset += eedev->pgsize)
+    {
+      ret = ee24xx_writepage(eedev, offset, buf, eedev->pgsize);
+      if (ret < 0)
+        {
+          ferr("ERROR: Failed to write page at offset %" PRIdOFF
+               " (ret = %d)",
+               offset, ret);
+          goto release_semaphore;
+        }
+
+      ret = ee24xx_waitwritecomplete(eedev, offset);
+      if (ret < 0)
+        {
+          ferr("ERROR while waiting for write at offset %" PRIdOFF
+               " to complete (ret = %d)",
+               offset, ret);
+          goto release_semaphore;
+        }
+    }
+
+release_semaphore:
+  nxmutex_unlock(&eedev->lock);
+
+free_buffer:
+  kmm_free(buf);
+  return ret;
+}
+
+/****************************************************************************
+ * Name: ee24xx_erasepage
+ *
+ * Description:
+ *   Erase 1 page of data
+ *
+ * Input Parameters:
+ *   eedev - Device structure
+ *   index - Index of the page to erase
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+static int ee24xx_erasepage(FAR struct ee24xx_dev_s *eedev,
+                            unsigned long index)
+{
+  FAR char *buf;
+  int       ret;
+  off_t     offset;
+
+  DEBUGASSERT(eedev);
+  DEBUGASSERT(eedev->pgsize > 0);
+
+  if (eedev->readonly)
+    {
+      return -EACCES;
+    }
+
+  if (index >= (eedev->size / eedev->pgsize))
+    {
+      return -EFBIG;
+    }
+
+  buf = kmm_malloc(eedev->pgsize);
+
+  if (buf == NULL)
+    {
+      ferr("ERROR: Failed to allocate memory for ee24xx_erasepage\n");
+      return -ENOMEM;
+    }
+
+  memset(buf, 0xff, eedev->pgsize);
+
+  ret = nxmutex_lock(&eedev->lock);
+  if (ret < 0)
+    {
+      goto free_buffer;
+    }
+
+  offset = index * eedev->pgsize;
+  ret    = ee24xx_writepage(eedev, offset, buf, eedev->pgsize);
+  if (ret < 0)
+    {
+      ferr("ERROR: Failed to write page (ret = %d)", ret);
+      goto release_semaphore;
+    }
+
+  ret = ee24xx_waitwritecomplete(eedev, offset);
+  if (ret < 0)
+    {
+      ferr("ERROR while waiting for write to complete (ret = %d)", ret);
+    }
+
+release_semaphore:
+  nxmutex_unlock(&eedev->lock);
+
+free_buffer:
+  kmm_free(buf);
+  return ret;
+}
+
 /****************************************************************************
  * Driver Functions
  ****************************************************************************/
@@ -814,6 +955,15 @@ static int ee24xx_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
         }
         break;
 
+      case EEPIOC_PAGEERASE:
+      case EEPIOC_SECTORERASE:
+        ret = ee24xx_erasepage(eedev, arg);
+        break;
+
+      case EEPIOC_CHIPERASE:
+        ret = ee24xx_eraseall(eedev);
+        break;
+
       default:
         ret = -ENOTTY;
     }