1 files changed, 507 insertions, 0 deletions

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
new file mode 100644
index 000000000000..aeb982969629
--- /dev/null
+++ b/drivers/thunderbolt/switch.c
@@ -0,0 +1,507 @@
+/*
+ * Thunderbolt Cactus Ridge driver - switch/port utility functions
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+#include "tb.h"
+
+/* port utility functions */
+
+static const char *tb_port_type(struct tb_regs_port_header *port)
+{
+	switch (port->type >> 16) {
+	case 0:
+		switch ((u8) port->type) {
+		case 0:
+			return "Inactive";
+		case 1:
+			return "Port";
+		case 2:
+			return "NHI";
+		default:
+			return "unknown";
+		}
+	case 0x2:
+		return "Ethernet";
+	case 0x8:
+		return "SATA";
+	case 0xe:
+		return "DP/HDMI";
+	case 0x10:
+		return "PCIe";
+	case 0x20:
+		return "USB";
+	default:
+		return "unknown";
+	}
+}
+
+static void tb_dump_port(struct tb *tb, struct tb_regs_port_header *port)
+{
+	tb_info(tb,
+		" Port %d: %x:%x (Revision: %d, TB Version: %d, Type: %s (%#x))\n",
+		port->port_number, port->vendor_id, port->device_id,
+		port->revision, port->thunderbolt_version, tb_port_type(port),
+		port->type);
+	tb_info(tb, "  Max hop id (in/out): %d/%d\n",
+		port->max_in_hop_id, port->max_out_hop_id);
+	tb_info(tb, "  Max counters: %d\n", port->max_counters);
+	tb_info(tb, "  NFC Credits: %#x\n", port->nfc_credits);
+}
+
+/**
+ * tb_port_state() - get connectedness state of a port
+ *
+ * The port must have a TB_CAP_PHY (i.e. it should be a real port).
+ *
+ * Return: Returns an enum tb_port_state on success or an error code on failure.
+ */
+static int tb_port_state(struct tb_port *port)
+{
+	struct tb_cap_phy phy;
+	int res;
+	if (port->cap_phy == 0) {
+		tb_port_WARN(port, "does not have a PHY\n");
+		return -EINVAL;
+	}
+	res = tb_port_read(port, &phy, TB_CFG_PORT, port->cap_phy, 2);
+	if (res)
+		return res;
+	return phy.state;
+}
+
+/**
+ * tb_wait_for_port() - wait for a port to become ready
+ *
+ * Wait up to 1 second for a port to reach state TB_PORT_UP. If
+ * wait_if_unplugged is set then we also wait if the port is in state
+ * TB_PORT_UNPLUGGED (it takes a while for the device to be registered after
+ * switch resume). Otherwise we only wait if a device is registered but the link
+ * has not yet been established.
+ *
+ * Return: Returns an error code on failure. Returns 0 if the port is not
+ * connected or failed to reach state TB_PORT_UP within one second. Returns 1
+ * if the port is connected and in state TB_PORT_UP.
+ */
+int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
+{
+	int retries = 10;
+	int state;
+	if (!port->cap_phy) {
+		tb_port_WARN(port, "does not have PHY\n");
+		return -EINVAL;
+	}
+	if (tb_is_upstream_port(port)) {
+		tb_port_WARN(port, "is the upstream port\n");
+		return -EINVAL;
+	}
+
+	while (retries--) {
+		state = tb_port_state(port);
+		if (state < 0)
+			return state;
+		if (state == TB_PORT_DISABLED) {
+			tb_port_info(port, "is disabled (state: 0)\n");
+			return 0;
+		}
+		if (state == TB_PORT_UNPLUGGED) {
+			if (wait_if_unplugged) {
+				/* used during resume */
+				tb_port_info(port,
+					     "is unplugged (state: 7), retrying...\n");
+				msleep(100);
+				continue;
+			}
+			tb_port_info(port, "is unplugged (state: 7)\n");
+			return 0;
+		}
+		if (state == TB_PORT_UP) {
+			tb_port_info(port,
+				     "is connected, link is up (state: 2)\n");
+			return 1;
+		}
+
+		/*
+		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
+		 * time.
+		 */
+		tb_port_info(port,
+			     "is connected, link is not up (state: %d), retrying...\n",
+			     state);
+		msleep(100);
+	}
+	tb_port_warn(port,
+		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
+	return 0;
+}
+
+/**
+ * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
+ *
+ * Change the number of NFC credits allocated to @port by @credits. To remove
+ * NFC credits pass a negative amount of credits.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_port_add_nfc_credits(struct tb_port *port, int credits)
+{
+	if (credits == 0)
+		return 0;
+	tb_port_info(port,
+		     "adding %#x NFC credits (%#x -> %#x)",
+		     credits,
+		     port->config.nfc_credits,
+		     port->config.nfc_credits + credits);
+	port->config.nfc_credits += credits;
+	return tb_port_write(port, &port->config.nfc_credits,
+			     TB_CFG_PORT, 4, 1);
+}
+
+/**
+ * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_port_clear_counter(struct tb_port *port, int counter)
+{
+	u32 zero[3] = { 0, 0, 0 };
+	tb_port_info(port, "clearing counter %d\n", counter);
+	return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
+}
+
+/**
+ * tb_init_port() - initialize a port
+ *
+ * This is a helper method for tb_switch_alloc. Does not check or initialize
+ * any downstream switches.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_init_port(struct tb_port *port)
+{
+	int res;
+	int cap;
+
+	res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
+	if (res)
+		return res;
+
+	/* Port 0 is the switch itself and has no PHY. */
+	if (port->config.type == TB_TYPE_PORT && port->port != 0) {
+		cap = tb_find_cap(port, TB_CFG_PORT, TB_CAP_PHY);
+
+		if (cap > 0)
+			port->cap_phy = cap;
+		else
+			tb_port_WARN(port, "non switch port without a PHY\n");
+	}
+
+	tb_dump_port(port->sw->tb, &port->config);
+
+	/* TODO: Read dual link port, DP port and more from EEPROM. */
+	return 0;
+
+}
+
+/* switch utility functions */
+
+static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
+{
+	tb_info(tb,
+		" Switch: %x:%x (Revision: %d, TB Version: %d)\n",
+		sw->vendor_id, sw->device_id, sw->revision,
+		sw->thunderbolt_version);
+	tb_info(tb, "  Max Port Number: %d\n", sw->max_port_number);
+	tb_info(tb, "  Config:\n");
+	tb_info(tb,
+		"   Upstream Port Number: %d Depth: %d Route String: %#llx Enabled: %d, PlugEventsDelay: %dms\n",
+		sw->upstream_port_number, sw->depth,
+		(((u64) sw->route_hi) << 32) | sw->route_lo,
+		sw->enabled, sw->plug_events_delay);
+	tb_info(tb,
+		"   unknown1: %#x unknown4: %#x\n",
+		sw->__unknown1, sw->__unknown4);
+}
+
+/**
+ * reset_switch() - reconfigure route, enable and send TB_CFG_PKG_RESET
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_switch_reset(struct tb *tb, u64 route)
+{
+	struct tb_cfg_result res;
+	struct tb_regs_switch_header header = {
+		header.route_hi = route >> 32,
+		header.route_lo = route,
+		header.enabled = true,
+	};
+	tb_info(tb, "resetting switch at %llx\n", route);
+	res.err = tb_cfg_write(tb->ctl, ((u32 *) &header) + 2, route,
+			0, 2, 2, 2);
+	if (res.err)
+		return res.err;
+	res = tb_cfg_reset(tb->ctl, route, TB_CFG_DEFAULT_TIMEOUT);
+	if (res.err > 0)
+		return -EIO;
+	return res.err;
+}
+
+struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route)
+{
+	u8 next_port = route; /*
+			       * Routes use a stride of 8 bits,
+			       * eventhough a port index has 6 bits at most.
+			       * */
+	if (route == 0)
+		return sw;
+	if (next_port > sw->config.max_port_number)
+		return NULL;
+	if (tb_is_upstream_port(&sw->ports[next_port]))
+		return NULL;
+	if (!sw->ports[next_port].remote)
+		return NULL;
+	return get_switch_at_route(sw->ports[next_port].remote->sw,
+				   route >> TB_ROUTE_SHIFT);
+}
+
+/**
+ * tb_plug_events_active() - enable/disable plug events on a switch
+ *
+ * Also configures a sane plug_events_delay of 255ms.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_plug_events_active(struct tb_switch *sw, bool active)
+{
+	u32 data;
+	int res;
+
+	sw->config.plug_events_delay = 0xff;
+	res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
+	if (res)
+		return res;
+
+	res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
+	if (res)
+		return res;
+
+	if (active) {
+		data = data & 0xFFFFFF83;
+		switch (sw->config.device_id) {
+		case 0x1513:
+		case 0x151a:
+		case 0x1549:
+			break;
+		default:
+			data |= 4;
+		}
+	} else {
+		data = data | 0x7c;
+	}
+	return tb_sw_write(sw, &data, TB_CFG_SWITCH,
+			   sw->cap_plug_events + 1, 1);
+}
+
+
+/**
+ * tb_switch_free() - free a tb_switch and all downstream switches
+ */
+void tb_switch_free(struct tb_switch *sw)
+{
+	int i;
+	/* port 0 is the switch itself and never has a remote */
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		if (tb_is_upstream_port(&sw->ports[i]))
+			continue;
+		if (sw->ports[i].remote)
+			tb_switch_free(sw->ports[i].remote->sw);
+		sw->ports[i].remote = NULL;
+	}
+
+	if (!sw->is_unplugged)
+		tb_plug_events_active(sw, false);
+
+	kfree(sw->ports);
+	kfree(sw->drom);
+	kfree(sw);
+}
+
+/**
+ * tb_switch_alloc() - allocate and initialize a switch
+ *
+ * Return: Returns a NULL on failure.
+ */
+struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
+{
+	int i;
+	int cap;
+	struct tb_switch *sw;
+	int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
+	if (upstream_port < 0)
+		return NULL;
+
+	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
+	if (!sw)
+		return NULL;
+
+	sw->tb = tb;
+	if (tb_cfg_read(tb->ctl, &sw->config, route, 0, 2, 0, 5))
+		goto err;
+	tb_info(tb,
+		"initializing Switch at %#llx (depth: %d, up port: %d)\n",
+		route, tb_route_length(route), upstream_port);
+	tb_info(tb, "old switch config:\n");
+	tb_dump_switch(tb, &sw->config);
+
+	/* configure switch */
+	sw->config.upstream_port_number = upstream_port;
+	sw->config.depth = tb_route_length(route);
+	sw->config.route_lo = route;
+	sw->config.route_hi = route >> 32;
+	sw->config.enabled = 1;
+	/* from here on we may use the tb_sw_* functions & macros */
+
+	if (sw->config.vendor_id != 0x8086)
+		tb_sw_warn(sw, "unknown switch vendor id %#x\n",
+			   sw->config.vendor_id);
+
+	if (sw->config.device_id != 0x1547 && sw->config.device_id != 0x1549)
+		tb_sw_warn(sw, "unsupported switch device id %#x\n",
+			   sw->config.device_id);
+
+	/* upload configuration */
+	if (tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3))
+		goto err;
+
+	/* initialize ports */
+	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
+				GFP_KERNEL);
+	if (!sw->ports)
+		goto err;
+
+	for (i = 0; i <= sw->config.max_port_number; i++) {
+		/* minimum setup for tb_find_cap and tb_drom_read to work */
+		sw->ports[i].sw = sw;
+		sw->ports[i].port = i;
+	}
+
+	cap = tb_find_cap(&sw->ports[0], TB_CFG_SWITCH, TB_CAP_PLUG_EVENTS);
+	if (cap < 0) {
+		tb_sw_warn(sw, "cannot find TB_CAP_PLUG_EVENTS aborting\n");
+		goto err;
+	}
+	sw->cap_plug_events = cap;
+
+	/* read drom */
+	if (tb_drom_read(sw))
+		tb_sw_warn(sw, "tb_eeprom_read_rom failed, continuing\n");
+	tb_sw_info(sw, "uid: %#llx\n", sw->uid);
+
+	for (i = 0; i <= sw->config.max_port_number; i++) {
+		if (sw->ports[i].disabled) {
+			tb_port_info(&sw->ports[i], "disabled by eeprom\n");
+			continue;
+		}
+		if (tb_init_port(&sw->ports[i]))
+			goto err;
+	}
+
+	/* TODO: I2C, IECS, link controller */
+
+	if (tb_plug_events_active(sw, true))
+		goto err;
+
+	return sw;
+err:
+	kfree(sw->ports);
+	kfree(sw->drom);
+	kfree(sw);
+	return NULL;
+}
+
+/**
+ * tb_sw_set_unpplugged() - set is_unplugged on switch and downstream switches
+ */
+void tb_sw_set_unpplugged(struct tb_switch *sw)
+{
+	int i;
+	if (sw == sw->tb->root_switch) {
+		tb_sw_WARN(sw, "cannot unplug root switch\n");
+		return;
+	}
+	if (sw->is_unplugged) {
+		tb_sw_WARN(sw, "is_unplugged already set\n");
+		return;
+	}
+	sw->is_unplugged = true;
+	for (i = 0; i <= sw->config.max_port_number; i++) {
+		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
+			tb_sw_set_unpplugged(sw->ports[i].remote->sw);
+	}
+}
+
+int tb_switch_resume(struct tb_switch *sw)
+{
+	int i, err;
+	u64 uid;
+	tb_sw_info(sw, "resuming switch\n");
+
+	err = tb_drom_read_uid_only(sw, &uid);
+	if (err) {
+		tb_sw_warn(sw, "uid read failed\n");
+		return err;
+	}
+	if (sw->uid != uid) {
+		tb_sw_info(sw,
+			"changed while suspended (uid %#llx -> %#llx)\n",
+			sw->uid, uid);
+		return -ENODEV;
+	}
+
+	/* upload configuration */
+	err = tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3);
+	if (err)
+		return err;
+
+	err = tb_plug_events_active(sw, true);
+	if (err)
+		return err;
+
+	/* check for surviving downstream switches */
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		struct tb_port *port = &sw->ports[i];
+		if (tb_is_upstream_port(port))
+			continue;
+		if (!port->remote)
+			continue;
+		if (tb_wait_for_port(port, true) <= 0
+			|| tb_switch_resume(port->remote->sw)) {
+			tb_port_warn(port,
+				     "lost during suspend, disconnecting\n");
+			tb_sw_set_unpplugged(port->remote->sw);
+		}
+	}
+	return 0;
+}
+
+void tb_switch_suspend(struct tb_switch *sw)
+{
+	int i, err;
+	err = tb_plug_events_active(sw, false);
+	if (err)
+		return;
+
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
+			tb_switch_suspend(sw->ports[i].remote->sw);
+	}
+	/*
+	 * TODO: invoke tb_cfg_prepare_to_sleep here? does not seem to have any
+	 * effect?
+	 */
+}