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path: root/drivers/thunderbolt/cap.c
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Diffstat (limited to 'drivers/thunderbolt/cap.c')
-rw-r--r--drivers/thunderbolt/cap.c169
1 files changed, 91 insertions, 78 deletions
diff --git a/drivers/thunderbolt/cap.c b/drivers/thunderbolt/cap.c
index a7b47e7cddbd..38bc27a5ce4f 100644
--- a/drivers/thunderbolt/cap.c
+++ b/drivers/thunderbolt/cap.c
@@ -9,6 +9,8 @@
#include "tb.h"
+#define CAP_OFFSET_MAX 0xff
+#define VSE_CAP_OFFSET_MAX 0xffff
struct tb_cap_any {
union {
@@ -18,99 +20,110 @@ struct tb_cap_any {
};
} __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)
+/**
+ * tb_port_find_cap() - Find port capability
+ * @port: Port to find the capability for
+ * @cap: Capability to look
+ *
+ * Returns offset to start of capability or %-ENOENT if no such
+ * capability was found. Negative errno is returned if there was an
+ * error.
+ */
+int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap)
{
- return !tb_cap_is_basic(cap)
- && cap->extended_short.next == 0
- && cap->extended_short.length == 0;
-}
+ u32 offset;
-static enum tb_cap tb_cap(struct tb_cap_any *cap)
-{
- if (tb_cap_is_basic(cap))
- return cap->basic.cap;
+ /*
+ * DP out adapters claim to implement TMU capability but in
+ * reality they do not so we hard code the adapter specific
+ * capability offset here.
+ */
+ if (port->config.type == TB_TYPE_DP_HDMI_OUT)
+ offset = 0x39;
else
- /* extended_short/long have cap at the same offset. */
- return cap->extended_short.cap;
+ offset = 0x1;
+
+ do {
+ struct tb_cap_any header;
+ int ret;
+
+ ret = tb_port_read(port, &header, TB_CFG_PORT, offset, 1);
+ if (ret)
+ return ret;
+
+ if (header.basic.cap == cap)
+ return offset;
+
+ offset = header.basic.next;
+ } while (offset);
+
+ return -ENOENT;
}
-static u32 tb_cap_next(struct tb_cap_any *cap, u32 offset)
+static int tb_switch_find_cap(struct tb_switch *sw, enum tb_switch_cap cap)
{
- 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;
+ int offset = sw->config.first_cap_offset;
+
+ while (offset > 0 && offset < CAP_OFFSET_MAX) {
+ struct tb_cap_any header;
+ int ret;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 1);
+ if (ret)
+ return ret;
+
+ if (header.basic.cap == cap)
+ return offset;
+
+ offset = header.basic.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;
+
+ return -ENOENT;
}
/**
- * tb_find_cap() - find a capability
+ * tb_switch_find_vse_cap() - Find switch vendor specific capability
+ * @sw: Switch to find the capability for
+ * @vsec: Vendor specific capability to look
*
- * Return: Returns a positive offset if the capability was found and 0 if not.
- * Returns an error code on failure.
+ * Functions enumerates vendor specific capabilities (VSEC) of a switch
+ * and returns offset when capability matching @vsec is found. If no
+ * such capability is found returns %-ENOENT. In case of error returns
+ * negative errno.
*/
-int tb_find_cap(struct tb_port *port, enum tb_cfg_space space, enum tb_cap cap)
+int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec)
{
- 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)
+ int offset;
+
+ offset = tb_switch_find_cap(sw, TB_SWITCH_CAP_VSE);
+ if (offset < 0)
+ return offset;
+
+ while (offset > 0 && offset < VSE_CAP_OFFSET_MAX) {
+ int ret;
+
+ ret = tb_sw_read(sw, &header, TB_CFG_SWITCH, offset, 2);
+ if (ret)
+ return ret;
+
+ /*
+ * Extended vendor specific capabilities come in two
+ * flavors: short and long. The latter is used when
+ * offset is over 0xff.
+ */
+ if (offset >= CAP_OFFSET_MAX) {
+ if (header.extended_long.vsec_id == vsec)
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 = header.extended_long.next;
+ } else {
+ if (header.extended_short.vsec_id == vsec)
+ return offset;
+ if (!header.extended_short.length)
+ return -ENOENT;
+ offset = header.extended_short.next;
}
- 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;
+
+ return -ENOENT;
}