Return-Path: From: "Felipe F. Tonello" To: linux-bluetooth@vger.kernel.org Subject: [PATCH v2 BlueZ 4/7] profiles/gap: Added support for PPCP characteristic Date: Thu, 16 Feb 2017 18:03:12 +0000 Message-Id: <20170216180315.30531-5-eu@felipetonello.com> In-Reply-To: <20170216180315.30531-1-eu@felipetonello.com> References: <20170216180315.30531-1-eu@felipetonello.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: The Peripheral Preferred Connection Parameters (PPCP) characteristic contains the preferred connection parameters of a peripheral device. These parameters are stored in the info file and loaded to Kernel using MGMT's respective command. IMPORTANT: The connection will only be updated upon next reconnection to the peripheral device. This is a limitation of the current BlueZ API that doesn't allow change specific parameters of current connection. --- profiles/gap/gas.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) diff --git a/profiles/gap/gas.c b/profiles/gap/gas.c index 0d34503ad446..a9f09f0b3299 100644 --- a/profiles/gap/gas.c +++ b/profiles/gap/gas.c @@ -162,6 +162,75 @@ static void handle_appearance(struct gas *gas, uint16_t value_handle) DBG("Failed to send request to read appearance"); } +static void read_ppcp_cb(bool success, uint8_t att_ecode, + const uint8_t *value, uint16_t length, + void *user_data) +{ + struct gas *gas = user_data; + uint16_t min_interval, max_interval, latency, timeout, max_latency; + + if (!success) { + DBG("Reading PPCP failed with ATT error: %u", att_ecode); + return; + } + + if (length != 8) { + DBG("Malformed PPCP value"); + return; + } + + min_interval = get_le16(&value[0]); + max_interval = get_le16(&value[2]); + latency = get_le16(&value[4]); + timeout = get_le16(&value[6]); + + DBG("GAP Peripheral Preferred Connection Parameters:"); + DBG("\tMinimum connection interval: %u", min_interval); + DBG("\tMaximum connection interval: %u", max_interval); + DBG("\tSlave latency: %u", latency); + DBG("\tConnection Supervision timeout multiplier: %u", timeout); + + /* 0xffff indicates no specific min/max */ + if (min_interval == 0xffff) + min_interval = 6; + + if (max_interval == 0xffff) + max_interval = 3200; + + /* avoid persisting connection parameters that are not valid */ + if (min_interval > max_interval || + min_interval < 6 || max_interval > 3200) { + warn("GAS PPCP: Invalid Connection Parameters values"); + return; + } + + if (timeout < 10 || timeout > 3200) { + warn("GAS PPCP: Invalid Connection Parameters values"); + return; + } + + if (max_interval >= timeout * 8) { + warn("GAS PPCP: Invalid Connection Parameters values"); + return; + } + + max_latency = (timeout * 4 / max_interval) - 1; + if (latency > 499 || latency > max_latency) { + warn("GAS PPCP: Invalid Connection Parameters values"); + return; + } + + btd_device_set_conn_param(gas->device, min_interval, max_interval, + latency, timeout); +} + +static void handle_ppcp(struct gas *gas, uint16_t value_handle) +{ + if (!bt_gatt_client_read_value(gas->client, value_handle, + read_ppcp_cb, gas, NULL)) + DBG("Failed to send request to read PPCP"); +} + static inline bool uuid_cmp(uint16_t u16, const bt_uuid_t *uuid) { bt_uuid_t lhs; @@ -188,6 +257,8 @@ static void handle_characteristic(struct gatt_db_attribute *attr, handle_device_name(gas, value_handle); else if (uuid_cmp(GATT_CHARAC_APPEARANCE, &uuid)) handle_appearance(gas, value_handle); + else if (uuid_cmp(GATT_CHARAC_PERIPHERAL_PREF_CONN, &uuid)) + handle_ppcp(gas, value_handle); else { char uuid_str[MAX_LEN_UUID_STR]; -- 2.11.1