NFC: Add firmware upload netlink command

As several NFC chipsets can have their firmwares upgraded and
reflashed, this patchset adds a new netlink command to trigger
that the driver loads or flashes a new firmware. This will allows
userspace triggered firmware upgrade through netlink.
The firmware name or hint is passed as a parameter, and the driver
will eventually fetch the firmware binary through the request_firmware
API.
The cmd can only be executed when the nfc dev is not in use. Actual
firmware loading/flashing is an asynchronous operation. Result of the
operation shall send a new event up to user space through the nfc dev
multicast socket. During operation, the nfc dev is not openable and
thus not usable.

Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

3 files changed, 114 insertions, 0 deletions

diff --git a/net/nfc/core.c b/net/nfc/core.c
index 40d2527693da..eb3cecf1764e 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -44,6 +44,47 @@ DEFINE_MUTEX(nfc_devlist_mutex);
 /* NFC device ID bitmap */
 static DEFINE_IDA(nfc_index_ida);
 
+int nfc_fw_upload(struct nfc_dev *dev, const char *firmware_name)
+{
+	int rc = 0;
+
+	pr_debug("%s do firmware %s\n", dev_name(&dev->dev), firmware_name);
+
+	device_lock(&dev->dev);
+
+	if (!device_is_registered(&dev->dev)) {
+		rc = -ENODEV;
+		goto error;
+	}
+
+	if (dev->dev_up) {
+		rc = -EBUSY;
+		goto error;
+	}
+
+	if (!dev->ops->fw_upload) {
+		rc = -EOPNOTSUPP;
+		goto error;
+	}
+
+	dev->fw_upload_in_progress = true;
+	rc = dev->ops->fw_upload(dev, firmware_name);
+	if (rc)
+		dev->fw_upload_in_progress = false;
+
+error:
+	device_unlock(&dev->dev);
+	return rc;
+}
+
+int nfc_fw_upload_done(struct nfc_dev *dev, const char *firmware_name)
+{
+	dev->fw_upload_in_progress = false;
+
+	return nfc_genl_fw_upload_done(dev, firmware_name);
+}
+EXPORT_SYMBOL(nfc_fw_upload_done);
+
 /**
  * nfc_dev_up - turn on the NFC device
  *
@@ -69,6 +110,11 @@ int nfc_dev_up(struct nfc_dev *dev)
 		goto error;
 	}
 
+	if (dev->fw_upload_in_progress) {
+		rc = -EBUSY;
+		goto error;
+	}
+
 	if (dev->dev_up) {
 		rc = -EALREADY;
 		goto error;
diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index f0c4d61f37c0..1deadad9a285 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -56,6 +56,8 @@ static const struct nla_policy nfc_genl_policy[NFC_ATTR_MAX + 1] = {
 	[NFC_ATTR_LLC_PARAM_RW] = { .type = NLA_U8 },
 	[NFC_ATTR_LLC_PARAM_MIUX] = { .type = NLA_U16 },
 	[NFC_ATTR_LLC_SDP] = { .type = NLA_NESTED },
+	[NFC_ATTR_FIRMWARE_NAME] = { .type = NLA_STRING,
+				     .len = NFC_FIRMWARE_NAME_MAXSIZE },
 };
 
 static const struct nla_policy nfc_sdp_genl_policy[NFC_SDP_ATTR_MAX + 1] = {
@@ -1025,6 +1027,62 @@ exit:
 	return rc;
 }
 
+static int nfc_genl_fw_upload(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nfc_dev *dev;
+	int rc;
+	u32 idx;
+	char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
+
+	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
+		return -EINVAL;
+
+	idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
+
+	dev = nfc_get_device(idx);
+	if (!dev)
+		return -ENODEV;
+
+	nla_strlcpy(firmware_name, info->attrs[NFC_ATTR_FIRMWARE_NAME],
+		    sizeof(firmware_name));
+
+	rc = nfc_fw_upload(dev, firmware_name);
+
+	nfc_put_device(dev);
+	return rc;
+}
+
+int nfc_genl_fw_upload_done(struct nfc_dev *dev, const char *firmware_name)
+{
+	struct sk_buff *msg;
+	void *hdr;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(msg, 0, 0, &nfc_genl_family, 0,
+			  NFC_CMD_FW_UPLOAD);
+	if (!hdr)
+		goto free_msg;
+
+	if (nla_put_string(msg, NFC_ATTR_FIRMWARE_NAME, firmware_name) ||
+	    nla_put_u32(msg, NFC_ATTR_DEVICE_INDEX, dev->idx))
+		goto nla_put_failure;
+
+	genlmsg_end(msg, hdr);
+
+	genlmsg_multicast(msg, 0, nfc_genl_event_mcgrp.id, GFP_KERNEL);
+
+	return 0;
+
+nla_put_failure:
+	genlmsg_cancel(msg, hdr);
+free_msg:
+	nlmsg_free(msg);
+	return -EMSGSIZE;
+}
+
 static struct genl_ops nfc_genl_ops[] = {
 	{
 		.cmd = NFC_CMD_GET_DEVICE,
@@ -1084,6 +1142,11 @@ static struct genl_ops nfc_genl_ops[] = {
 		.doit = nfc_genl_llc_sdreq,
 		.policy = nfc_genl_policy,
 	},
+	{
+		.cmd = NFC_CMD_FW_UPLOAD,
+		.doit = nfc_genl_fw_upload,
+		.policy = nfc_genl_policy,
+	},
 };
 
 
diff --git a/net/nfc/nfc.h b/net/nfc/nfc.h
index afa1f84ba040..cf0c48165996 100644
--- a/net/nfc/nfc.h
+++ b/net/nfc/nfc.h
@@ -120,6 +120,11 @@ static inline void nfc_device_iter_exit(struct class_dev_iter *iter)
 	class_dev_iter_exit(iter);
 }
 
+int nfc_fw_upload(struct nfc_dev *dev, const char *firmware_name);
+int nfc_genl_fw_upload_done(struct nfc_dev *dev, const char *firmware_name);
+
+int nfc_fw_upload_done(struct nfc_dev *dev, const char *firmware_name);
+
 int nfc_dev_up(struct nfc_dev *dev);
 
 int nfc_dev_down(struct nfc_dev *dev);