Messages in this thread Patch in this message | | | From | Sanath S <> | Subject | [Patch v3 1/4] thunderbolt: Introduce usb4_port_reset() and tb_lc_reset_port() | Date | Sat, 6 Jan 2024 22:27:20 +0530 |
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Introduce the usb4_port_reset() function that performs the DPR of a given port. This function follows the CM guide specification 7.3
Introduce tb_lc_reset_port() function that performs the DPR through link control registers. Supports non-USB4 routers like TBT2 and TBT3.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Sanath S <Sanath.S@amd.com> --- drivers/thunderbolt/lc.c | 44 +++++++++++++++++++++++++++++++++++ drivers/thunderbolt/tb_regs.h | 4 ++++ drivers/thunderbolt/usb4.c | 39 +++++++++++++++++++++++++++++++ 3 files changed, 87 insertions(+)
diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c index 633970fbe9b0..de7276909a42 100644 --- a/drivers/thunderbolt/lc.c +++ b/drivers/thunderbolt/lc.c @@ -5,6 +5,7 @@ * Copyright (C) 2019, Intel Corporation * Author: Mika Westerberg <mika.westerberg@linux.intel.com> */ +#include <linux/delay.h> #include "tb.h" @@ -45,6 +46,49 @@ 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); diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h index 87e4795275fe..efcae298b370 100644 --- a/drivers/thunderbolt/tb_regs.h +++ b/drivers/thunderbolt/tb_regs.h @@ -389,6 +389,7 @@ struct tb_regs_port_header { #define PORT_CS_18_CSA BIT(22) #define PORT_CS_18_TIP BIT(24) #define PORT_CS_19 0x13 +#define PORT_CS_19_DPR BIT(0) #define PORT_CS_19_PC BIT(3) #define PORT_CS_19_PID BIT(4) #define PORT_CS_19_WOC BIT(16) @@ -584,6 +585,9 @@ struct tb_regs_hop { #define TB_LC_POWER 0x740 /* Link controller registers */ +#define TB_LC_PORT_MODE 0x26 +#define TB_LC_PORT_MODE_DPR BIT(0) + #define TB_LC_CS_42 0x2a #define TB_LC_CS_42_USB_PLUGGED BIT(31) diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c index f8f0d24ff6e4..4b35898aa216 100644 --- a/drivers/thunderbolt/usb4.c +++ b/drivers/thunderbolt/usb4.c @@ -1113,6 +1113,45 @@ int usb4_port_hotplug_enable(struct tb_port *port) return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_5, 1); } +/** + * usb4_port_reset() - Issue downstream port reset + * @port: USB4 port to reset + * + * Issues downstream port reset to @port. + */ +int usb4_port_reset(struct tb_port *port) +{ + int ret; + u32 val; + + if (!port->cap_usb4) + return -EINVAL; + + ret = tb_port_read(port, &val, TB_CFG_PORT, + port->cap_usb4 + PORT_CS_19, 1); + if (ret) + return ret; + + val |= PORT_CS_19_DPR; + + ret = tb_port_write(port, &val, TB_CFG_PORT, + port->cap_usb4 + PORT_CS_19, 1); + if (ret) + return ret; + + fsleep(10000); + + ret = tb_port_read(port, &val, TB_CFG_PORT, + port->cap_usb4 + PORT_CS_19, 1); + if (ret) + return ret; + + val &= ~PORT_CS_19_DPR; + + return tb_port_write(port, &val, TB_CFG_PORT, + port->cap_usb4 + PORT_CS_19, 1); +} + static int usb4_port_set_configured(struct tb_port *port, bool configured) { int ret; -- 2.34.1
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