1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Thunderbolt link controller support 4 * 5 * Copyright (C) 2019, Intel Corporation 6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com> 7 */ 8 9 #include "tb.h" 10 11 /** 12 * tb_lc_read_uuid() - Read switch UUID from link controller common register 13 * @sw: Switch whose UUID is read 14 * @uuid: UUID is placed here 15 */ 16 int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid) 17 { 18 if (!sw->cap_lc) 19 return -EINVAL; 20 return tb_sw_read(sw, uuid, TB_CFG_SWITCH, sw->cap_lc + TB_LC_FUSE, 4); 21 } 22 23 static int read_lc_desc(struct tb_switch *sw, u32 *desc) 24 { 25 if (!sw->cap_lc) 26 return -EINVAL; 27 return tb_sw_read(sw, desc, TB_CFG_SWITCH, sw->cap_lc + TB_LC_DESC, 1); 28 } 29 30 static int find_port_lc_cap(struct tb_port *port) 31 { 32 struct tb_switch *sw = port->sw; 33 int start, phys, ret, size; 34 u32 desc; 35 36 ret = read_lc_desc(sw, &desc); 37 if (ret) 38 return ret; 39 40 /* Start of port LC registers */ 41 start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT; 42 size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT; 43 phys = tb_phy_port_from_link(port->port); 44 45 return sw->cap_lc + start + phys * size; 46 } 47 48 static int tb_lc_configure_lane(struct tb_port *port, bool configure) 49 { 50 bool upstream = tb_is_upstream_port(port); 51 struct tb_switch *sw = port->sw; 52 u32 ctrl, lane; 53 int cap, ret; 54 55 if (sw->generation < 2) 56 return 0; 57 58 cap = find_port_lc_cap(port); 59 if (cap < 0) 60 return cap; 61 62 ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1); 63 if (ret) 64 return ret; 65 66 /* Resolve correct lane */ 67 if (port->port % 2) 68 lane = TB_LC_SX_CTRL_L1C; 69 else 70 lane = TB_LC_SX_CTRL_L2C; 71 72 if (configure) { 73 ctrl |= lane; 74 if (upstream) 75 ctrl |= TB_LC_SX_CTRL_UPSTREAM; 76 } else { 77 ctrl &= ~lane; 78 if (upstream) 79 ctrl &= ~TB_LC_SX_CTRL_UPSTREAM; 80 } 81 82 return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1); 83 } 84 85 /** 86 * tb_lc_configure_link() - Let LC know about configured link 87 * @sw: Switch that is being added 88 * 89 * Informs LC of both parent switch and @sw that there is established 90 * link between the two. 91 */ 92 int tb_lc_configure_link(struct tb_switch *sw) 93 { 94 struct tb_port *up, *down; 95 int ret; 96 97 if (!sw->config.enabled || !tb_route(sw)) 98 return 0; 99 100 up = tb_upstream_port(sw); 101 down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent)); 102 103 /* Configure parent link toward this switch */ 104 ret = tb_lc_configure_lane(down, true); 105 if (ret) 106 return ret; 107 108 /* Configure upstream link from this switch to the parent */ 109 ret = tb_lc_configure_lane(up, true); 110 if (ret) 111 tb_lc_configure_lane(down, false); 112 113 return ret; 114 } 115 116 /** 117 * tb_lc_unconfigure_link() - Let LC know about unconfigured link 118 * @sw: Switch to unconfigure 119 * 120 * Informs LC of both parent switch and @sw that the link between the 121 * two does not exist anymore. 122 */ 123 void tb_lc_unconfigure_link(struct tb_switch *sw) 124 { 125 struct tb_port *up, *down; 126 127 if (sw->is_unplugged || !sw->config.enabled || !tb_route(sw)) 128 return; 129 130 up = tb_upstream_port(sw); 131 down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent)); 132 133 tb_lc_configure_lane(up, false); 134 tb_lc_configure_lane(down, false); 135 } 136 137 /** 138 * tb_lc_set_sleep() - Inform LC that the switch is going to sleep 139 * @sw: Switch to set sleep 140 * 141 * Let the switch link controllers know that the switch is going to 142 * sleep. 143 */ 144 int tb_lc_set_sleep(struct tb_switch *sw) 145 { 146 int start, size, nlc, ret, i; 147 u32 desc; 148 149 if (sw->generation < 2) 150 return 0; 151 152 ret = read_lc_desc(sw, &desc); 153 if (ret) 154 return ret; 155 156 /* Figure out number of link controllers */ 157 nlc = desc & TB_LC_DESC_NLC_MASK; 158 start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT; 159 size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT; 160 161 /* For each link controller set sleep bit */ 162 for (i = 0; i < nlc; i++) { 163 unsigned int offset = sw->cap_lc + start + i * size; 164 u32 ctrl; 165 166 ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, 167 offset + TB_LC_SX_CTRL, 1); 168 if (ret) 169 return ret; 170 171 ctrl |= TB_LC_SX_CTRL_SLP; 172 ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, 173 offset + TB_LC_SX_CTRL, 1); 174 if (ret) 175 return ret; 176 } 177 178 return 0; 179 } 180