diff options
| author | Edward Hill <ecgh@chromium.org> | 2020-08-29 17:23:44 -0600 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2020-09-03 19:18:34 +0000 |
| commit | 463967bcaa76158527af3cd337c7e06677fd751f (patch) | |
| tree | ca2429cba8142bdc4838d55bcee7ee30a7706411 /driver/tcpm/nct38xx.c | |
| parent | 81832b5d2e00c5d606d78f8cbd6b4074af75c0c0 (diff) | |
| download | chrome-ec-463967bcaa76158527af3cd337c7e06677fd751f.tar.gz | |
nct38xx: Only disable SNKEN if we are sink
Disabling SNKEN makes the VBSNK_EN pin Hi-Z, so USB_Cx_TCPC_VBSNK_EN_L
will be asserted by external pull-down, so only do so if already
sinking, otherwise both source and sink switches can be closed,
which should never happen.
BUG=b:166850036 b:166527561
BRANCH=zork
TEST=EC reboot with sink device in C0 and charger in C1
Signed-off-by: Edward Hill <ecgh@chromium.org>
Change-Id: Ib4400a16b02e47eca109b95bf912b7f23325c8af
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2384009
Reviewed-by: Denis Brockus <dbrockus@chromium.org>
Tested-by: Denis Brockus <dbrockus@chromium.org>
Diffstat (limited to 'driver/tcpm/nct38xx.c')
| -rw-r--r-- | driver/tcpm/nct38xx.c | 54 |
1 files changed, 46 insertions, 8 deletions
diff --git a/driver/tcpm/nct38xx.c b/driver/tcpm/nct38xx.c index 308cefe928..79e46fa12a 100644 --- a/driver/tcpm/nct38xx.c +++ b/driver/tcpm/nct38xx.c @@ -98,6 +98,7 @@ static int nct38xx_init(int port) return rv; } + static int nct38xx_tcpm_init(int port) { int rv; @@ -109,12 +110,11 @@ static int nct38xx_tcpm_init(int port) return nct38xx_init(port); } -int nct38xx_tcpm_set_cc(int port, int pull) +static int nct38xx_tcpm_set_cc(int port, int pull) { /* * Setting the CC lines to open/open requires that the NCT CTRL_OUT - * register has sink disabled. Otherwise the following happens, as - * described by Nuvoton: + * register has sink disabled. Otherwise, when no battery is connected: * * 1. You set CC lines to Open/Open. This is physically happening on * the CC line. @@ -125,20 +125,58 @@ int nct38xx_tcpm_set_cc(int port, int pull) * 4. When TCPC VCC gets below ~2.7V the TCPC will reset and therefore * it will present Rd/Rd on the CC lines. Also the VBSNK_EN pin * after reset is Hi-Z, so the sink switch will get closed again. + * + * Disabling SNKEN makes the VBSNK_EN pin Hi-Z, so + * USB_Cx_TCPC_VBSNK_EN_L will be asserted by external + * pull-down, so only do so if already sinking, otherwise + * both source and sink switches can be closed, which should + * never happen (b/166850036). + * + * SNKEN will be re-enabled in nct38xx_init above (from tcpm_init), or + * when CC lines are set again, or when sinking is disabled. */ + enum mask_update_action action = MASK_SET; + int rv; + if (pull == TYPEC_CC_OPEN) { - int rv; + bool is_sinking; + + rv = tcpm_get_snk_ctrl(port, &is_sinking); + if (rv) + return rv; + + if (is_sinking) + action = MASK_CLR; + } + + rv = tcpc_update8(port, + NCT38XX_REG_CTRL_OUT_EN, + NCT38XX_REG_CTRL_OUT_EN_SNKEN, + action); + if (rv) + return rv; + + return tcpci_tcpm_set_cc(port, pull); +} + +static int nct38xx_tcpm_set_snk_ctrl(int port, int enable) +{ + int rv; - /* Disable SNKEN, it will be re-enabled in tcpm_init path */ + /* + * To disable sinking, SNKEN must be enabled so that + * USB_Cx_TCPC_VBSNK_EN_L will be driven high. + */ + if (!enable) { rv = tcpc_update8(port, NCT38XX_REG_CTRL_OUT_EN, NCT38XX_REG_CTRL_OUT_EN_SNKEN, - MASK_CLR); + MASK_SET); if (rv) return rv; } - return tcpci_tcpm_set_cc(port, pull); + return tcpci_tcpm_set_snk_ctrl(port, enable); } static void nct38xx_tcpc_alert(int port) @@ -222,7 +260,7 @@ const struct tcpm_drv nct38xx_tcpm_drv = { #endif #ifdef CONFIG_USBC_PPC .get_snk_ctrl = &tcpci_tcpm_get_snk_ctrl, - .set_snk_ctrl = &tcpci_tcpm_set_snk_ctrl, + .set_snk_ctrl = &nct38xx_tcpm_set_snk_ctrl, .get_src_ctrl = &tcpci_tcpm_get_src_ctrl, .set_src_ctrl = &tcpci_tcpm_set_src_ctrl, #endif |