adding erase functions for w1 eeprom

dev/sdb-eeprom.c

@@ -43,6 +43,11 @@ static int sdb_w1_write(struct sdbfs *fs, int offset, void *buf, int count)
 	return w1_write_eeprom_bus(fs->drvdata, offset, buf, count);
 }
 
+static int sdb_w1_erase(struct sdbfs *fs, int offset, int count)
+{
+	return w1_erase_eeprom_bus(fs->drvdata, offset, count);
+}
+
 /*
  * I2C code.
  * The functions in ./eeprom.c (legacy) are replicated here with the sdb
@@ -191,6 +196,7 @@ void eeprom_init(int chosen_i2cif, int chosen_i2c_addr)
 		wrc_sdb.drvdata = &wrpc_w1_bus;
 		wrc_sdb.read = sdb_w1_read;
 		wrc_sdb.write = sdb_w1_write;
+		wrc_sdb.erase = sdb_w1_erase;
 		goto found_exit;
 	}
 

dev/w1-eeprom.c

@@ -49,6 +49,44 @@ static int w1_write_page(struct w1_dev *dev, int offset, const uint8_t *buffer,
 	return blen;
 }
 
+static int w1_erase_page(struct w1_dev *dev, int offset, int blen)
+{
+	int i, j, es;
+
+	/* First, write scratchpad */
+	w1_match_rom(dev);
+	w1_write_byte(dev->bus, W1_CMDR_W_SPAD);
+	w1_write_byte(dev->bus, LSB_ADDR(offset));
+	w1_write_byte(dev->bus, MSB_ADDR(offset));
+	for(i = 0; i < blen; i++)
+		w1_write_byte(dev->bus, 0xFF);
+
+	/* Then, read it back, and remember the return E/S */
+	w1_match_rom(dev);
+	w1_write_byte(dev->bus, W1_CMDR_R_SPAD);
+	if (w1_read_byte(dev->bus) != LSB_ADDR(offset))
+		return -1;
+	if (w1_read_byte(dev->bus) != MSB_ADDR(offset))
+		return -2;
+	es = w1_read_byte(dev->bus);
+	for(i = 0; i < blen; i++) {
+		j = w1_read_byte(dev->bus);
+		if (j != 0xFF)
+			return -3;
+	}
+
+	/* Finally, "copy scratchpad" to actually write */
+	w1_match_rom(dev);
+	w1_write_byte(dev->bus, W1_CMDR_C_SPAD);
+	w1_write_byte(dev->bus, LSB_ADDR(offset));
+	w1_write_byte(dev->bus, MSB_ADDR(offset));
+	w1_write_byte(dev->bus, es);
+	usleep(10000); /* 10ms, in theory */
+
+	/* Don't read back, as nothing useful is there (I get 0xf9, why?) */
+	return blen;
+}
+
 int w1_write_eeprom(struct w1_dev *dev, int offset, const uint8_t *buffer,
 		    int blen)
 {
@@ -106,6 +144,43 @@ int w1_read_eeprom(struct w1_dev *dev, int offset, uint8_t *buffer, int blen)
 	return blen;
 }
 
+int w1_erase_eeprom(struct w1_dev *dev, int offset, int blen)
+{
+	int i, page, endpage;
+	int ret = 0;
+
+	/* Split the write into several page-local writes */
+	page = offset / 32;
+	endpage = (offset + blen - 1) / 32;
+
+	/* Traling part of first page */
+	if (offset % 32) {
+		if (endpage != page)
+			i = 32 - (offset % 32);
+		else
+			i = blen;
+		ret += w1_erase_page(dev, offset, i);
+		if (ret < 0)
+			return ret;
+		offset += i;
+		blen -= i;
+	}
+
+	/* Whole pages and leading part of last page */
+	while (blen > 0 ) {
+		i = blen;
+		if (blen > 32)
+			i = 32;
+		i = w1_erase_page(dev, offset, i);
+		if (i < 0)
+			return i;
+		ret += i;
+		offset += 32;
+		blen -= 32;
+	}
+	return ret;
+}
+
 
 int w1_read_eeprom_bus(struct w1_bus *bus,
 			    int offset, uint8_t *buffer, int blen)
@@ -136,3 +211,16 @@ int w1_write_eeprom_bus(struct w1_bus *bus,
 	/* not found */
 	return -1;
 }
+
+int w1_erase_eeprom_bus(struct w1_bus *bus, int offset, int blen)
+{
+	int i, class;
+
+	for (i = 0; i < W1_MAX_DEVICES; i++) {
+		class = w1_class(bus->devs + i);
+		if (class == 0x43)
+			return w1_erase_eeprom(bus->devs + i, offset, blen);
+	}
+	/* not found */
+	return -1;
+}

include/w1.h

@@ -72,6 +72,7 @@ extern int w1_read_eeprom(struct w1_dev *dev,
 			  int offset, uint8_t *buffer, int blen);
 extern int w1_write_eeprom(struct w1_dev *dev,
 			   int offset, const uint8_t *buffer, int blen);
+extern int w1_erase_eeprom(struct w1_dev *dev, int offset, int blen);
 
 /* These are generic, using the first suitable device in the bus */
 extern int32_t w1_read_temp_bus(struct w1_bus *bus, unsigned long flags);
@@ -79,6 +80,7 @@ extern int w1_read_eeprom_bus(struct w1_bus *bus,
 			    int offset, uint8_t *buffer, int blen);
 extern int w1_write_eeprom_bus(struct w1_bus *bus,
 			     int offset, const uint8_t *buffer, int blen);
+extern int w1_erase_eeprom_bus(struct w1_bus *bus, int offset, int blen);
 
 extern struct w1_ops wrpc_w1_ops;
 extern struct w1_bus wrpc_w1_bus;