diff options
Diffstat (limited to 'drivers/thunderbolt/lc.c')
| -rw-r--r-- | drivers/thunderbolt/lc.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c index 633970fbe9..63cb4b6afb 100644 --- a/drivers/thunderbolt/lc.c +++ b/drivers/thunderbolt/lc.c @@ -6,6 +6,8 @@ * Author: Mika Westerberg <mika.westerberg@linux.intel.com> */ +#include <linux/delay.h> + #include "tb.h" /** @@ -45,6 +47,49 @@ static int find_port_lc_cap(struct tb_port *port) return sw->cap_lc + start + phys * size; } +/** + * tb_lc_reset_port() - Trigger downstream port reset through LC + * @port: Port that is reset + * + * Triggers downstream port reset through link controller registers. + * Returns %0 in case of success negative errno otherwise. Only supports + * non-USB4 routers with link controller (that's Thunderbolt 2 and + * Thunderbolt 3). + */ +int tb_lc_reset_port(struct tb_port *port) +{ + struct tb_switch *sw = port->sw; + int cap, ret; + u32 mode; + + if (sw->generation < 2) + return -EINVAL; + + cap = find_port_lc_cap(port); + if (cap < 0) + return cap; + + ret = tb_sw_read(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); + if (ret) + return ret; + + mode |= TB_LC_PORT_MODE_DPR; + + ret = tb_sw_write(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); + if (ret) + return ret; + + fsleep(10000); + + ret = tb_sw_read(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); + if (ret) + return ret; + + mode &= ~TB_LC_PORT_MODE_DPR; + + return tb_sw_write(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1); +} + static int tb_lc_set_port_configured(struct tb_port *port, bool configured) { bool upstream = tb_is_upstream_port(port); |