ieee802154: add TX power control to wpan_phy

Replace the current u8 transmit_power in wpan_phy with s8 transmit_power.
The u8 field contained the actual tx power and a tolerance field,
which no physical radio every used. Adjust sysfs entries to keep
compatibility with userspace, give tolerances of +-1dB statically there.

This patch only adds support for this in the at86rf230 driver and the
RF212 chip. Configuration calculation for RF212 is also somewhat basic,
but does the job - the RF212 datasheet gives a large table with
suggested values for combinations of TX power and page/channel, if this
does not work well, we might have to copy the whole table.

Signed-off-by: Phoebe Buckheister <phoebe.buckheister@itwm.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 53 insertions, 4 deletions

diff --git a/net/ieee802154/ieee802154.h b/net/ieee802154/ieee802154.h
index cee4425..6cbc896 100644
--- a/net/ieee802154/ieee802154.h
+++ b/net/ieee802154/ieee802154.h
@@ -53,6 +53,7 @@ int ieee802154_list_phy(struct sk_buff *skb, struct genl_info *info);
 int ieee802154_dump_phy(struct sk_buff *skb, struct netlink_callback *cb);
 int ieee802154_add_iface(struct sk_buff *skb, struct genl_info *info);
 int ieee802154_del_iface(struct sk_buff *skb, struct genl_info *info);
+int ieee802154_set_phyparams(struct sk_buff *skb, struct genl_info *info);
 
 enum ieee802154_mcgrp_ids {
 	IEEE802154_COORD_MCGRP,
diff --git a/net/ieee802154/netlink.c b/net/ieee802154/netlink.c
index 43f1b2b..67c151b 100644
--- a/net/ieee802154/netlink.c
+++ b/net/ieee802154/netlink.c
@@ -115,6 +115,7 @@ static const struct genl_ops ieee8021154_ops[] = {
 			ieee802154_dump_phy),
 	IEEE802154_OP(IEEE802154_ADD_IFACE, ieee802154_add_iface),
 	IEEE802154_OP(IEEE802154_DEL_IFACE, ieee802154_del_iface),
+	IEEE802154_OP(IEEE802154_SET_PHYPARAMS, ieee802154_set_phyparams),
 	/* see nl-mac.c */
 	IEEE802154_OP(IEEE802154_ASSOCIATE_REQ, ieee802154_associate_req),
 	IEEE802154_OP(IEEE802154_ASSOCIATE_RESP, ieee802154_associate_resp),
diff --git a/net/ieee802154/nl-phy.c b/net/ieee802154/nl-phy.c
index 89b265a..d3ee62f 100644
--- a/net/ieee802154/nl-phy.c
+++ b/net/ieee802154/nl-phy.c
@@ -55,7 +55,8 @@ static int ieee802154_nl_fill_phy(struct sk_buff *msg, u32 portid,
 	mutex_lock(&phy->pib_lock);
 	if (nla_put_string(msg, IEEE802154_ATTR_PHY_NAME, wpan_phy_name(phy)) ||
 	    nla_put_u8(msg, IEEE802154_ATTR_PAGE, phy->current_page) ||
-	    nla_put_u8(msg, IEEE802154_ATTR_CHANNEL, phy->current_channel))
+	    nla_put_u8(msg, IEEE802154_ATTR_CHANNEL, phy->current_channel) ||
+	    nla_put_s8(msg, IEEE802154_ATTR_TXPOWER, phy->transmit_power))
 		goto nla_put_failure;
 	for (i = 0; i < 32; i++) {
 		if (phy->channels_supported[i])
@@ -354,3 +355,49 @@ out_dev:
 
 	return rc;
 }
+
+int ieee802154_set_phyparams(struct sk_buff *skb, struct genl_info *info)
+{
+	struct wpan_phy *phy;
+	const char *name;
+	int txpower;
+	int rc = -EINVAL;
+
+	pr_debug("%s\n", __func__);
+
+	if (!info->attrs[IEEE802154_ATTR_PHY_NAME])
+		return -EINVAL;
+
+	name = nla_data(info->attrs[IEEE802154_ATTR_PHY_NAME]);
+	if (name[nla_len(info->attrs[IEEE802154_ATTR_PHY_NAME]) - 1] != '\0')
+		return -EINVAL; /* phy name should be null-terminated */
+
+	txpower = nla_get_s8(info->attrs[IEEE802154_ATTR_TXPOWER]);
+
+	phy = wpan_phy_find(name);
+	if (!phy)
+		return -ENODEV;
+
+	if (!phy->set_txpower)
+		goto out;
+
+	mutex_lock(&phy->pib_lock);
+
+	rc = phy->set_txpower(phy, txpower);
+	if (rc < 0) {
+		mutex_unlock(&phy->pib_lock);
+		goto out;
+	}
+
+	phy->transmit_power = txpower;
+
+	mutex_unlock(&phy->pib_lock);
+
+	wpan_phy_put(phy);
+
+	return 0;
+
+out:
+	wpan_phy_put(phy);
+	return rc;
+}
diff --git a/net/ieee802154/nl_policy.c b/net/ieee802154/nl_policy.c
index 6adda4d..90b1d0d 100644
--- a/net/ieee802154/nl_policy.c
+++ b/net/ieee802154/nl_policy.c
@@ -52,5 +52,7 @@ const struct nla_policy ieee802154_policy[IEEE802154_ATTR_MAX + 1] = {
 	[IEEE802154_ATTR_DURATION] = { .type = NLA_U8, },
 	[IEEE802154_ATTR_ED_LIST] = { .len = 27 },
 	[IEEE802154_ATTR_CHANNEL_PAGE_LIST] = { .len = 32 * 4, },
+
+	[IEEE802154_ATTR_TXPOWER] = { .type = NLA_S8, },
 };
 
diff --git a/net/ieee802154/wpan-class.c b/net/ieee802154/wpan-class.c
index 4dd3761..8d6f670 100644
--- a/net/ieee802154/wpan-class.c
+++ b/net/ieee802154/wpan-class.c
@@ -44,9 +44,7 @@ static DEVICE_ATTR_RO(name);
 
 MASTER_SHOW(current_channel, "%d");
 MASTER_SHOW(current_page, "%d");
-MASTER_SHOW_COMPLEX(transmit_power, "%d +- %d dB",
-	((signed char) (phy->transmit_power << 2)) >> 2,
-	(phy->transmit_power >> 6) ? (phy->transmit_power >> 6) * 3 : 1);
+MASTER_SHOW(transmit_power, "%d +- 1 dB");
 MASTER_SHOW(cca_mode, "%d");
 
 static ssize_t channels_supported_show(struct device *dev,