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>

5 files changed, 122 insertions, 0 deletions

diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h
index 5eb80bb3cbb2..3563dbdcaaf2 100644
--- a/include/net/nfc/nfc.h
+++ b/include/net/nfc/nfc.h
@@ -70,6 +70,7 @@ struct nfc_ops {
         int (*check_presence)(struct nfc_dev *dev, struct nfc_target *target);
         int (*enable_se)(struct nfc_dev *dev, u32 secure_element);
         int (*disable_se)(struct nfc_dev *dev, u32 secure_element);
+        int (*fw_upload)(struct nfc_dev *dev, const char *firmware_name);
 };
 
 #define NFC_TARGET_IDX_ANY -1
@@ -104,6 +105,7 @@ struct nfc_dev {
         int targets_generation;
         struct device dev;
         bool dev_up;
+        bool fw_upload_in_progress;
         u8 rf_mode;
         bool polling;
         struct nfc_target *active_target;
diff --git a/include/uapi/linux/nfc.h b/include/uapi/linux/nfc.h
index 7c6f627a717d..b6cbd164f146 100644
--- a/include/uapi/linux/nfc.h
+++ b/include/uapi/linux/nfc.h
@@ -69,6 +69,8 @@
  *      starting a poll from a device which has a secure element enabled means
  *      we want to do SE based card emulation.
  * @NFC_CMD_DISABLE_SE: Disable the physical link to a specific secure element.
+ * @NFC_CMD_FW_UPLOAD: Request to Load/flash firmware, or event to inform that
+ *      some firmware was loaded
  */
 enum nfc_commands {
         NFC_CMD_UNSPEC,
@@ -92,6 +94,7 @@ enum nfc_commands {
         NFC_CMD_DISABLE_SE,
         NFC_CMD_LLC_SDREQ,
         NFC_EVENT_LLC_SDRES,
+        NFC_CMD_FW_UPLOAD,
 /* private: internal use only */
         __NFC_CMD_AFTER_LAST
 };
@@ -121,6 +124,7 @@ enum nfc_commands {
  * @NFC_ATTR_LLC_PARAM_RW: Receive Window size parameter
  * @NFC_ATTR_LLC_PARAM_MIUX: MIU eXtension parameter
  * @NFC_ATTR_SE: Available Secure Elements
+ * @NFC_ATTR_FIRMWARE_NAME: Free format firmware version
  */
 enum nfc_attrs {
         NFC_ATTR_UNSPEC,
@@ -143,6 +147,7 @@ enum nfc_attrs {
         NFC_ATTR_LLC_PARAM_MIUX,
         NFC_ATTR_SE,
         NFC_ATTR_LLC_SDP,
+        NFC_ATTR_FIRMWARE_NAME,
 /* private: internal use only */
         __NFC_ATTR_AFTER_LAST
 };
@@ -162,6 +167,7 @@ enum nfc_sdp_attr {
 #define NFC_SENSB_RES_MAXSIZE 12
 #define NFC_SENSF_RES_MAXSIZE 18
 #define NFC_GB_MAXSIZE        48
+#define NFC_FIRMWARE_NAME_MAXSIZE 32
 
 /* NFC protocols */
 #define NFC_PROTO_JEWEL         1
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);