thunderbolt: Rename and make nvm_read() available for other files

In order to support non-Intel NVM formats the vendor specific NVM
validation code that will live in nvm.c needs to be able to read various
parts of the NVM so make the function available outside of switch.c and
rename it accordingly.
Signed-off-by: Szuying Chen <Chloe_Chen@asmedia.com.tw>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/switch.c

@@ -300,14 +300,6 @@ static inline bool nvm_upgradeable(struct tb_switch *sw)
 	return nvm_readable(sw);
 }
 
-static inline int nvm_read(struct tb_switch *sw, unsigned int address,
-			   void *buf, size_t size)
-{
-	if (tb_switch_is_usb4(sw))
-		return usb4_switch_nvm_read(sw, address, buf, size);
-	return dma_port_flash_read(sw->dma_port, address, buf, size);
-}
-
 static int nvm_authenticate(struct tb_switch *sw, bool auth_only)
 {
 	int ret;
@@ -335,8 +327,26 @@ static int nvm_authenticate(struct tb_switch *sw, bool auth_only)
 	return ret;
 }
 
-static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
-			      size_t bytes)
+/**
+ * tb_switch_nvm_read() - Read router NVM
+ * @sw: Router whose NVM to read
+ * @address: Start address on the NVM
+ * @buf: Buffer where the read data is copied
+ * @size: Size of the buffer in bytes
+ *
+ * Reads from router NVM and returns the requested data in @buf. Locking
+ * is up to the caller. Returns %0 in success and negative errno in case
+ * of failure.
+ */
+int tb_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
+		       size_t size)
+{
+	if (tb_switch_is_usb4(sw))
+		return usb4_switch_nvm_read(sw, address, buf, size);
+	return dma_port_flash_read(sw->dma_port, address, buf, size);
+}
+
+static int nvm_read(void *priv, unsigned int offset, void *val, size_t bytes)
 {
 	struct tb_nvm *nvm = priv;
 	struct tb_switch *sw = tb_to_switch(nvm->dev);
@@ -349,7 +359,7 @@ static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
 		goto out;
 	}
 
-	ret = nvm_read(sw, offset, val, bytes);
+	ret = tb_switch_nvm_read(sw, offset, val, bytes);
 	mutex_unlock(&sw->tb->lock);
 
 out:
@@ -359,8 +369,7 @@ static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
 	return ret;
 }
 
-static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
-			       size_t bytes)
+static int nvm_write(void *priv, unsigned int offset, void *val, size_t bytes)
 {
 	struct tb_nvm *nvm = priv;
 	struct tb_switch *sw = tb_to_switch(nvm->dev);
@@ -415,7 +424,7 @@ static int tb_switch_nvm_add(struct tb_switch *sw)
 	if (!sw->safe_mode) {
 		u32 nvm_size, hdr_size;
 
-		ret = nvm_read(sw, NVM_FLASH_SIZE, &val, sizeof(val));
+		ret = tb_switch_nvm_read(sw, NVM_FLASH_SIZE, &val, sizeof(val));
 		if (ret)
 			goto err_nvm;
 
@@ -423,21 +432,20 @@ static int tb_switch_nvm_add(struct tb_switch *sw)
 		nvm_size = (SZ_1M << (val & 7)) / 8;
 		nvm_size = (nvm_size - hdr_size) / 2;
 
-		ret = nvm_read(sw, NVM_VERSION, &val, sizeof(val));
+		ret = tb_switch_nvm_read(sw, NVM_VERSION, &val, sizeof(val));
 		if (ret)
 			goto err_nvm;
 
 		nvm->major = (val >> 16) & 0xff;
 		nvm->minor = (val >> 8) & 0xff;
 
-		ret = tb_nvm_add_active(nvm, nvm_size, tb_switch_nvm_read);
+		ret = tb_nvm_add_active(nvm, nvm_size, nvm_read);
 		if (ret)
 			goto err_nvm;
 	}
 
 	if (!sw->no_nvm_upgrade) {
-		ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE,
-					    tb_switch_nvm_write);
+		ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE, nvm_write);
 		if (ret)
 			goto err_nvm;
 	}

drivers/thunderbolt/tb.h

@@ -759,6 +759,8 @@ int tb_nvm_write_data(unsigned int address, const void *buf, size_t size,
 		      unsigned int retries, write_block_fn write_next_block,
 		      void *write_block_data);
 
+int tb_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
+		       size_t size);
 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
 				  u64 route);
 struct tb_switch *tb_switch_alloc_safe_mode(struct tb *tb,