1 // SPDX-License-Identifier: GPL-2.0
3  * Thunderbolt driver - capabilities lookup
18 static int tb_port_enable_tmu(struct tb_port *port, bool enable)  in tb_port_enable_tmu()  argument
20 	struct tb_switch *sw = port->sw;  in tb_port_enable_tmu()
25 	 * Legacy devices need to have TMU access enabled before port  in tb_port_enable_tmu()
47 static void tb_port_dummy_read(struct tb_port *port)  in tb_port_dummy_read()  argument
50 	 * When reading from next capability pointer location in port  in tb_port_dummy_read()
53 	 * port capabilities are walked.  in tb_port_dummy_read()
55 	if (tb_switch_is_light_ridge(port->sw)) {  in tb_port_dummy_read()
58 		tb_port_read(port, &dummy, TB_CFG_PORT, 0, 1);  in tb_port_dummy_read()
63  * tb_port_next_cap() - Return next capability in the linked list
64  * @port: Port to find the capability for
67  * Returns dword offset of the next capability in port config space
72 int tb_port_next_cap(struct tb_port *port, unsigned int offset)  in tb_port_next_cap()  argument
78 		return port->config.first_cap_offset;  in tb_port_next_cap()
80 	ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);  in tb_port_next_cap()
87 static int __tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)  in __tb_port_find_cap()  argument
95 		offset = tb_port_next_cap(port, offset);  in __tb_port_find_cap()
99 		ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);  in __tb_port_find_cap()
107 	return -ENOENT;  in __tb_port_find_cap()
111  * tb_port_find_cap() - Find port capability
112  * @port: Port to find the capability for
115  * Returns offset to start of capability or %-ENOENT if no such
119 int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)  in tb_port_find_cap()  argument
123 	ret = tb_port_enable_tmu(port, true);  in tb_port_find_cap()
127 	ret = __tb_port_find_cap(port, cap);  in tb_port_find_cap()
129 	tb_port_dummy_read(port);  in tb_port_find_cap()
130 	tb_port_enable_tmu(port, false);  in tb_port_find_cap()
136  * tb_switch_next_cap() - Return next capability in the linked list
151 		return sw->config.first_cap_offset;  in tb_switch_next_cap()
172 		ret = -EINVAL;  in tb_switch_next_cap()
180  * tb_switch_find_cap() - Find switch capability
184  * Returns offset to start of capability or %-ENOENT if no such
208 	return -ENOENT;  in tb_switch_find_cap()
212  * tb_switch_find_vse_cap() - Find switch vendor specific capability
214  * @vsec: Vendor specific capability to look
216  * Functions enumerates vendor specific capabilities (VSEC) of a switch
218  * such capability is found returns %-ENOENT. In case of error returns
242 	return -ENOENT;  in tb_switch_find_vse_cap()