thunderbolt: Add thunderbolt capability handling (e2b8785e) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/thunderbolt/Makefile

+1 −1

Original line number	Diff line number	Diff line
		obj-${CONFIG_THUNDERBOLT} := thunderbolt.o
		thunderbolt-objs := nhi.o ctl.o tb.o switch.o
		thunderbolt-objs := nhi.o ctl.o tb.o switch.o cap.o

drivers/thunderbolt/cap.c

0 → 100644

+116 −0

Original line number	Diff line number	Diff line
		/*
		* Thunderbolt Cactus Ridge driver - capabilities lookup
		*
		* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
		*/

		#include <linux/slab.h>
		#include <linux/errno.h>

		#include "tb.h"


		struct tb_cap_any {
		union {
		struct tb_cap_basic basic;
		struct tb_cap_extended_short extended_short;
		struct tb_cap_extended_long extended_long;
		};
		} __packed;

		static bool tb_cap_is_basic(struct tb_cap_any *cap)
		{
		/* basic.cap is u8. This checks only the lower 8 bit of cap. */
		return cap->basic.cap != 5;
		}

		static bool tb_cap_is_long(struct tb_cap_any *cap)
		{
		return !tb_cap_is_basic(cap)
		&& cap->extended_short.next == 0
		&& cap->extended_short.length == 0;
		}

		static enum tb_cap tb_cap(struct tb_cap_any *cap)
		{
		if (tb_cap_is_basic(cap))
		return cap->basic.cap;
		else
		/* extended_short/long have cap at the same offset. */
		return cap->extended_short.cap;
		}

		static u32 tb_cap_next(struct tb_cap_any *cap, u32 offset)
		{
		int next;
		if (offset == 1) {
		/*
		* The first pointer is part of the switch header and always
		* a simple pointer.
		*/
		next = cap->basic.next;
		} else {
		/*
		* Somehow Intel decided to use 3 different types of capability
		* headers. It is not like anyone could have predicted that
		* single byte offsets are not enough...
		*/
		if (tb_cap_is_basic(cap))
		next = cap->basic.next;
		else if (!tb_cap_is_long(cap))
		next = cap->extended_short.next;
		else
		next = cap->extended_long.next;
		}
		/*
		* "Hey, we could terminate some capability lists with a null offset
		* and others with a pointer to the last element." - "Great idea!"
		*/
		if (next == offset)
		return 0;
		return next;
		}

		/**
		* tb_find_cap() - find a capability
		*
		* Return: Returns a positive offset if the capability was found and 0 if not.
		* Returns an error code on failure.
		*/
		int tb_find_cap(struct tb_port *port, enum tb_cfg_space space, enum tb_cap cap)
		{
		u32 offset = 1;
		struct tb_cap_any header;
		int res;
		int retries = 10;
		while (retries--) {
		res = tb_port_read(port, &header, space, offset, 1);
		if (res) {
		/* Intel needs some help with linked lists. */
		if (space == TB_CFG_PORT && offset == 0xa
		&& port->config.type == TB_TYPE_DP_HDMI_OUT) {
		offset = 0x39;
		continue;
		}
		return res;
		}
		if (offset != 1) {
		if (tb_cap(&header) == cap)
		return offset;
		if (tb_cap_is_long(&header)) {
		/* tb_cap_extended_long is 2 dwords */
		res = tb_port_read(port, &header, space,
		offset, 2);
		if (res)
		return res;
		}
		}
		offset = tb_cap_next(&header, offset);
		if (!offset)
		return 0;
		}
		tb_port_WARN(port,
		"run out of retries while looking for cap %#x in config space %d, last offset: %#x\n",
		cap, space, offset);
		return -EIO;
		}

drivers/thunderbolt/tb.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -159,6 +159,8 @@ void thunderbolt_shutdown_and_free(struct tb *tb);
		struct tb_switch tb_switch_alloc(struct tb tb, u64 route);
		void tb_switch_free(struct tb_switch *sw);

		int tb_find_cap(struct tb_port *port, enum tb_cfg_space space, u32 value);


		static inline int tb_route_length(u64 route)
		{