Revert "cr50: add support for enabling terminations on ap suspend"

This reverts commit cfcac78e626ce08ccc1c45c91c61127b6088e80f.

Reason for revert:  Removing all s3 termination support. It's not
necessary and it causes scarlet to boot into recovery.

Original change's description:
> cr50: add support for enabling terminations on ap suspend
>
> rk3399 systems need terminations on the SPI signals in S3 and all other
> low power states. Add support for enabling the pulldowns and pullups on
> the correct pins.
>
> With this change, if BOARD_NEEDS_S3_TERM is set in the board properties,
> cr50 will enable a pulldown on the AP TX Cr50 RX signal and a pulldown
> on all of the SPS signals. To keep the pulldowns from interfering with
> the sps peripheral, s3_term will also disable the input for those
> signals.
>
> BUG=b:62200096
> BRANCH=cr50
> TEST=Flash onto bob. Make sure cr50 enables and disables terminations
> when the AP suspends/resumes. Flash onto reef. Make sure it doesn't do
> anything.
>
> Change-Id: I4adaf6d66160bab1eb3cf3d343d4a79524ccf883
> Signed-off-by: Mary Ruthven <mruthven@google.com>
> Reviewed-on: https://chromium-review.googlesource.com/991338
> Commit-Ready: Mary Ruthven <mruthven@chromium.org>
> Tested-by: Mary Ruthven <mruthven@chromium.org>
> Reviewed-by: Randall Spangler <rspangler@chromium.org>

Bug: b:62200096
Change-Id: I00c5051a48d4578badf9ce6622dea1af9903f4fd
Reviewed-on: https://chromium-review.googlesource.com/1062687
Commit-Ready: Mary Ruthven <mruthven@chromium.org>
Tested-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>

7 files changed, 1 insertions, 124 deletions

diff --git a/board/cr50/ap_uart_state.c b/board/cr50/ap_uart_state.c
index c21e8b518c..42e2feeab4 100644
--- a/board/cr50/ap_uart_state.c
+++ b/board/cr50/ap_uart_state.c
@@ -21,12 +21,6 @@ void print_ap_uart_state(void)
 	ccprintf("AP UART: %s\n", device_state_name(state));
 }
 
-int ap_is_suspended(void)
-{
-	/* When the AP uart is off, that means the device is suspended. */
-	return state == DEVICE_STATE_OFF;
-}
-
 int ap_uart_is_on(void)
 {
 	/* Debouncing and on are both still on */
diff --git a/board/cr50/board.c b/board/cr50/board.c
index 4c68dde651..ba09d5ad32 100644
--- a/board/cr50/board.c
+++ b/board/cr50/board.c
@@ -149,11 +149,6 @@ int board_rst_pullup_needed(void)
 	return !!(board_properties & BOARD_NEEDS_SYS_RST_PULL_UP);
 }
 
-int board_needs_s3_term(void)
-{
-	return !!(board_properties & BOARD_NEEDS_S3_TERM);
-}
-
 int board_tpm_uses_i2c(void)
 {
 	return !!(board_properties & BOARD_SLAVE_CONFIG_I2C);
diff --git a/board/cr50/board.h b/board/cr50/board.h
index 92c4230620..cf179d5d11 100644
--- a/board/cr50/board.h
+++ b/board/cr50/board.h
@@ -262,9 +262,6 @@ int board_tpm_uses_spi(void);
 int board_id_is_mismatched(void);
 /* Allow for deep sleep to be enabled on AP shutdown */
 int board_deep_sleep_allowed(void);
-int board_needs_s3_term(void);
-int board_s3_term_is_enabled(void);
-void board_s3_term(int enable);
 
 void power_button_record(void);
 
@@ -285,7 +282,6 @@ void print_servo_state(void);
 
 int ap_is_on(void);
 int ap_uart_is_on(void);
-int ap_is_suspended(void);
 int ec_is_on(void);
 int ec_is_rx_allowed(void);
 int servo_is_connected(void);
diff --git a/board/cr50/build.mk b/board/cr50/build.mk
index 9d717572d4..e6c3725578 100644
--- a/board/cr50/build.mk
+++ b/board/cr50/build.mk
@@ -39,7 +39,6 @@ board-${CONFIG_RDD} += rdd.o
 board-${CONFIG_USB_SPI} += usb_spi.o
 board-${CONFIG_USB_I2C} += usb_i2c.o
 board-y += recovery_button.o
-board-y += s3_term.o
 board-y += tpm2/NVMem.o
 board-y += tpm2/aes.o
 board-y += tpm2/ecc.o
diff --git a/board/cr50/rdd.c b/board/cr50/rdd.c
index 15173ba70a..d59ca7d803 100644
--- a/board/cr50/rdd.c
+++ b/board/cr50/rdd.c
@@ -145,9 +145,6 @@ enum ccd_state_flag {
 
 	/* SPI port is enabled for AP and/or EC flash */
 	CCD_ENABLE_SPI			= (1 << 6),
-
-	/* S3 Terminations are enabled */
-	CCD_ENABLE_S3_TERM		= (1 << 7),
 };
 
 int console_is_restricted(void)
@@ -182,9 +179,6 @@ static uint32_t get_state_flags(void)
 	if (ccd_usb_spi.state->enabled_device)
 		flags_now |= CCD_ENABLE_SPI;
 
-	if (board_s3_term_is_enabled())
-		flags_now |= CCD_ENABLE_S3_TERM;
-
 	return flags_now;
 }
 
@@ -210,8 +204,6 @@ static void print_state_flags(enum console_channel channel, uint32_t flags)
 		cprintf(channel, " I2C");
 	if (flags & CCD_ENABLE_SPI)
 		cprintf(channel, " SPI");
-	if (flags & CCD_ENABLE_S3_TERM)
-		cprintf(channel, " S3_TERM");
 }
 
 static void ccd_state_change_hook(void)
@@ -250,10 +242,6 @@ static void ccd_state_change_hook(void)
 				CCD_ENABLE_UART_EC_BITBANG | CCD_ENABLE_I2C |
 				CCD_ENABLE_SPI);
 
-	/* Enable S3 Terminations */
-	if (ap_is_suspended() && board_needs_s3_term())
-		flags_want |= CCD_ENABLE_S3_TERM;
-
 	/* Disable based on capabilities */
 	if (!ccd_is_cap_enabled(CCD_CAP_GSC_RX_AP_TX))
 		flags_want &= ~CCD_ENABLE_UART_AP;
@@ -317,8 +305,6 @@ static void ccd_state_change_hook(void)
 		usb_i2c_board_disable();
 	if (delta & CCD_ENABLE_SPI)
 		usb_spi_enable(&ccd_usb_spi, 0);
-	if (delta & CCD_ENABLE_S3_TERM)
-		board_s3_term(0);
 
 	/* Handle turning things on */
 	delta = flags_want & ~flags_now;
@@ -338,8 +324,6 @@ static void ccd_state_change_hook(void)
 		usb_i2c_board_enable();
 	if (delta & CCD_ENABLE_SPI)
 		usb_spi_enable(&ccd_usb_spi, 1);
-	if (delta & CCD_ENABLE_S3_TERM)
-		board_s3_term(1);
 }
 DECLARE_DEFERRED(ccd_state_change_hook);
 
diff --git a/board/cr50/s3_term.c b/board/cr50/s3_term.c
deleted file mode 100644
index bb486d207e..0000000000
--- a/board/cr50/s3_term.c
+++ /dev/null
@@ -1,88 +0,0 @@
-/* Copyright 2018 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "console.h"
-#include "registers.h"
-
-#define CPRINTS(format, args...) cprints(CC_SYSTEM, format, ## args)
-#define CPRINTF(format, args...) cprintf(CC_SYSTEM, format, ## args)
-
-#define AP_TX_TERM	(1 << 0)
-#define SPS_TERM	(1 << 1)
-
-int term_enabled;
-
-static void update_term_state(int term, int enable)
-{
-	if (enable)
-		term_enabled |= term;
-	else
-		term_enabled &= ~term;
-}
-
-int board_s3_term_is_enabled(void)
-{
-	return term_enabled;
-}
-
-static void ap_tx_term_enable(int term_enable)
-{
-	/* Add a pulldown to AP TX Cr50 RX */
-	GWRITE_FIELD(PINMUX, DIOA3_CTL, PD, term_enable);
-	update_term_state(AP_TX_TERM, term_enable);
-}
-
-static void sps_enable_pd(int term_enable)
-{
-	GWRITE_FIELD(PINMUX, DIOA2_CTL, PD, term_enable);	/* SPS_MOSI */
-	GWRITE_FIELD(PINMUX, DIOA6_CTL, PD, term_enable);	/* SPS_CLK */
-	GWRITE_FIELD(PINMUX, DIOA10_CTL, PD, term_enable);	/* SPS_MISO */
-	GWRITE_FIELD(PINMUX, DIOA12_CTL, PD, term_enable);	/* SPS_CS_L */
-}
-
-static void sps_enable_inputs(int input_enable)
-{
-	GWRITE_FIELD(PINMUX, DIOA2_CTL, IE, input_enable);	/* SPS_MOSI */
-	GWRITE_FIELD(PINMUX, DIOA6_CTL, IE, input_enable);	/* SPS_CLK */
-	GWRITE_FIELD(PINMUX, DIOA10_CTL, IE, 0);		/* SPS_MISO */
-	GWRITE_FIELD(PINMUX, DIOA12_CTL, IE, input_enable);	/* SPS_CS_L */
-}
-
-static void sps_term_enable(int term_enable)
-{
-	/* Disable the sps inputs before enabling the pulldowns */
-	if (!term_enable)
-		sps_enable_inputs(!term_enable);
-
-	/* Control the pulldowns on the SPS signals */
-	sps_enable_pd(term_enable);
-
-	/* Reenable the sps inputs after enabling the pulldowns */
-	if (term_enable)
-		sps_enable_inputs(!term_enable);
-	update_term_state(SPS_TERM, term_enable);
-}
-
-void board_s3_term(int term_enable)
-{
-	if (!board_needs_s3_term() || (!term_enable == !term_enabled))
-		return;
-	CPRINTS("%sable S3 signal terminations", term_enable ? "En" : "Dis");
-
-	ap_tx_term_enable(term_enable);
-
-	if (!board_tpm_uses_i2c())
-		sps_term_enable(term_enable);
-}
-
-static int command_s3term(int argc, char **argv)
-{
-	ccprintf("Terminations:%s%s\n",
-		term_enabled & AP_TX_TERM ? " AP" : "",
-		term_enabled & SPS_TERM ? " SPS" : "");
-	return EC_SUCCESS;
-}
-DECLARE_CONSOLE_COMMAND(s3term, command_s3term, "",
-			"Get the state of the S3 termination signals");
diff --git a/board/cr50/scratch_reg1.h b/board/cr50/scratch_reg1.h
index 8802a9f5c5..4462212941 100644
--- a/board/cr50/scratch_reg1.h
+++ b/board/cr50/scratch_reg1.h
@@ -49,15 +49,12 @@
 #define BOARD_DEEP_SLEEP_DISABLED    (1 << 13)
 /* Use Cr50_RX_AP_TX to determine if the AP is off or on */
 #define BOARD_DETECT_AP_WITH_UART    (1 << 14)
-/* Add terminations to signals in S3 */
-#define BOARD_NEEDS_S3_TERM          (1 << 15)
 /*
  * Macro to capture all properties related to board strapping pins. This must be
  * updated if additional strap related properties are added.
  */
 #define BOARD_ALL_PROPERTIES (BOARD_SLAVE_CONFIG_SPI | BOARD_SLAVE_CONFIG_I2C \
 	| BOARD_NEEDS_SYS_RST_PULL_UP | BOARD_USE_PLT_RESET | \
-	BOARD_DEEP_SLEEP_DISABLED | BOARD_DETECT_AP_WITH_UART | \
-	BOARD_NEEDS_S3_TERM)
+	BOARD_DEEP_SLEEP_DISABLED | BOARD_DETECT_AP_WITH_UART)
 
 #endif  /* ! __EC_BOARD_CR50_SCRATCH_REG1_H */