From e8bd3c057ceb1c881ccd5112b577d94cd730b7d6 Mon Sep 17 00:00:00 2001 From: Keith Short Date: Thu, 25 Jun 2020 14:56:28 -0600 Subject: bb_retimer: add power up timing Ensure the Burnside Bridge is held in reset when the AP is off and add a delay to reset de-assertion to meet Burnside Bridge requirements. BUG=b:159743964 BRANCH=none TEST=make buildall TEST=Verify BB initialization is skipped when the AP is off (verified with extra debug) TEST=Verify operation of USB, DP, and USB4 devices on Burnside bridge. Signed-off-by: Keith Short Change-Id: I4a4f05aaf84bf93b3c3032998bc811591c8fbf35 Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2271697 Reviewed-by: Abe Levkoy --- driver/retimer/bb_retimer.c | 14 ++++++++++++++ driver/usb_mux/usb_mux.c | 14 +++++++++++--- 2 files changed, 25 insertions(+), 3 deletions(-) diff --git a/driver/retimer/bb_retimer.c b/driver/retimer/bb_retimer.c index 8855f049b1..b815bf1de4 100644 --- a/driver/retimer/bb_retimer.c +++ b/driver/retimer/bb_retimer.c @@ -6,6 +6,7 @@ */ #include "bb_retimer.h" +#include "chipset.h" #include "common.h" #include "console.h" #include "i2c.h" @@ -95,6 +96,12 @@ static void bb_retimer_power_handle(const struct usb_mux *me, int on_off) if (on_off) { gpio_set_level(control->usb_ls_en_gpio, 1); + /* + * Tpw, minimum time from VCC to RESET_N de-assertion is 100us. + * For boards that don't provide a load switch control, the + * retimer_init() function ensures power is up before calling + * this function. + */ msleep(1); gpio_set_level(control->retimer_rst_gpio, 1); msleep(10); @@ -417,6 +424,13 @@ static int retimer_init(const struct usb_mux *me) int rv; uint32_t data; + /* Burnside Bridge is powered by main AP rail */ + if (chipset_in_or_transitioning_to_state(CHIPSET_STATE_ANY_OFF)) { + /* Ensure reset is asserted while chip is not powered */ + bb_retimer_power_handle(me, 0); + return EC_ERROR_NOT_POWERED; + } + bb_retimer_power_handle(me, 1); rv = bb_retimer_read(me, BB_RETIMER_REG_VENDOR_ID, &data); diff --git a/driver/usb_mux/usb_mux.c b/driver/usb_mux/usb_mux.c index 911558905d..cfc91352bc 100644 --- a/driver/usb_mux/usb_mux.c +++ b/driver/usb_mux/usb_mux.c @@ -149,16 +149,24 @@ static inline void exit_low_power_mode(int port) void usb_mux_init(int port) { + int rv; + ASSERT(port >= 0 && port < CONFIG_USB_PD_PORT_MAX_COUNT); if (port >= board_get_usb_pd_port_count()) { return; } - configure_mux(port, USB_MUX_INIT, NULL); + rv = configure_mux(port, USB_MUX_INIT, NULL); - /* Device is always out of LPM after initialization. */ - flags[port] &= ~USB_MUX_FLAG_IN_LPM; + /* + * Mux may fail initialization if it's not powered. Mark this port + * as in LPM mode to try initialization again. + */ + if (rv == EC_ERROR_NOT_POWERED) + flags[port] |= USB_MUX_FLAG_IN_LPM; + else + flags[port] &= ~USB_MUX_FLAG_IN_LPM; } /* -- cgit v1.2.1