I2C: Remove unused arbitration support

The i2c_claim and i2c_release routines are no longer in use, removing
this code removes one odd usecase of the panic printing routines.

Signed-off-by: Anton Staaf <robotboy@chromium.org>

BRANCH=None
BUG=None
TEST=make buildall -j

Change-Id: I76c1d90738e1e39b4b3226c31085513a20bbd769
Reviewed-on: https://chromium-review.googlesource.com/296732
Commit-Ready: Anton Staaf <robotboy@chromium.org>
Tested-by: Anton Staaf <robotboy@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>

6 files changed, 0 insertions, 152 deletions

diff --git a/chip/nrf51/i2c.c b/chip/nrf51/i2c.c
index 668f4c6863..11d90ba05a 100644
--- a/chip/nrf51/i2c.c
+++ b/chip/nrf51/i2c.c
@@ -9,7 +9,6 @@
 #include "gpio.h"
 #include "hooks.h"
 #include "i2c.h"
-#include "i2c_arbitration.h"
 #include "registers.h"
 #include "task.h"
 #include "timer.h"
diff --git a/chip/stm32/i2c-stm32l.c b/chip/stm32/i2c-stm32l.c
index 90fe7aa0d7..cdca08a25a 100644
--- a/chip/stm32/i2c-stm32l.c
+++ b/chip/stm32/i2c-stm32l.c
@@ -12,7 +12,6 @@
 #include "hooks.h"
 #include "host_command.h"
 #include "i2c.h"
-#include "i2c_arbitration.h"
 #include "registers.h"
 #include "task.h"
 #include "timer.h"
diff --git a/common/build.mk b/common/build.mk
index f1aa62556b..2006cb8c69 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -51,7 +51,6 @@ common-$(CONFIG_GESTURE_DETECTION)+=gesture.o
 common-$(CONFIG_HOSTCMD_EVENTS)+=host_event_commands.o
 common-$(CONFIG_HOSTCMD_PD)+=host_command_master.o
 common-$(CONFIG_I2C)+=i2c.o
-common-$(CONFIG_I2C_ARBITRATION)+=i2c_arbitration.o
 common-$(CONFIG_INDUCTIVE_CHARGING)+=inductive_charging.o
 common-$(CONFIG_KEYBOARD_PROTOCOL_8042)+=keyboard_8042.o \
 	keyboard_8042_sharedlib.o
diff --git a/common/i2c_arbitration.c b/common/i2c_arbitration.c
deleted file mode 100644
index 128ef16287..0000000000
--- a/common/i2c_arbitration.c
+++ /dev/null
@@ -1,104 +0,0 @@
-/* Copyright (c) 2013 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.
- */
-/* I2C arbitration using a pair of GPIO lines */
-
-#include "chipset.h"
-#include "common.h"
-#include "gpio.h"
-#include "hooks.h"
-#include "i2c.h"
-#include "timer.h"
-#include "util.h"
-
-/* Time between requesting bus and deciding that we have it */
-#define BUS_SLEW_DELAY_US 10
-
-/* Time between retrying to see if the AP has released the bus */
-#define BUS_WAIT_RETRY_US 3000
-
-/* Time to wait until the bus becomes free */
-#define BUS_WAIT_FREE_US (100 * 1000)
-
-/*
- * This reflects the desired value of GPIO_EC_CLAIM to ensure that the
- * GPIO is driven correctly when re-enabled before AP power on.
- */
-static char i2c_claimed_by_ec;
-
-int i2c_claim(int port)
-{
-	timestamp_t start;
-
-	if (port != I2C_PORT_MASTER)
-		return EC_SUCCESS;
-
-	/* If AP is off, we have the bus */
-	if (chipset_in_state(CHIPSET_STATE_ANY_OFF)) {
-		i2c_claimed_by_ec = 1;
-		return EC_SUCCESS;
-	}
-
-	/* Start a round of trying to claim the bus */
-	start = get_time();
-	do {
-		timestamp_t start_retry;
-		int waiting = 0;
-
-		/* Indicate that we want to claim the bus */
-		gpio_set_level(GPIO_EC_CLAIM, 0);
-		usleep(BUS_SLEW_DELAY_US);
-
-		/* Wait for the AP to release it */
-		start_retry = get_time();
-		while (time_since32(start_retry) < BUS_WAIT_RETRY_US) {
-			if (gpio_get_level(GPIO_AP_CLAIM)) {
-				/* We got it, so return */
-				i2c_claimed_by_ec = 1;
-				return EC_SUCCESS;
-			}
-
-			if (!waiting)
-				waiting = 1;
-		}
-
-		/* It didn't release, so give up, wait, and try again */
-		gpio_set_level(GPIO_EC_CLAIM, 1);
-
-		usleep(BUS_WAIT_RETRY_US);
-	} while (time_since32(start) < BUS_WAIT_FREE_US);
-
-	gpio_set_level(GPIO_EC_CLAIM, 1);
-	usleep(BUS_SLEW_DELAY_US);
-	i2c_claimed_by_ec = 0;
-
-	panic_puts("Unable to access I2C bus (arbitration timeout)\n");
-	return EC_ERROR_BUSY;
-}
-
-void i2c_release(int port)
-{
-	if (port == I2C_PORT_MASTER) {
-		/* Release our claim */
-		gpio_set_level(GPIO_EC_CLAIM, 1);
-		usleep(BUS_SLEW_DELAY_US);
-		i2c_claimed_by_ec = 0;
-	}
-}
-
-static void i2c_pre_init_hook(void)
-{
-	gpio_set_flags(GPIO_AP_CLAIM, GPIO_PULL_UP);
-	gpio_set_level(GPIO_EC_CLAIM, i2c_claimed_by_ec ? 0 : 1);
-	gpio_set_flags(GPIO_EC_CLAIM, GPIO_OUTPUT);
-	usleep(BUS_SLEW_DELAY_US);
-}
-DECLARE_HOOK(HOOK_CHIPSET_PRE_INIT, i2c_pre_init_hook, HOOK_PRIO_DEFAULT);
-
-static void i2c_shutdown_hook(void)
-{
-	gpio_set_flags(GPIO_AP_CLAIM, GPIO_INPUT);
-	gpio_set_flags(GPIO_EC_CLAIM, GPIO_INPUT);
-}
-DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, i2c_shutdown_hook, HOOK_PRIO_DEFAULT);
diff --git a/include/config.h b/include/config.h
index be35fa09c9..946e9dcf5b 100644
--- a/include/config.h
+++ b/include/config.h
@@ -951,7 +951,6 @@
 /* I2C configuration */
 
 #undef CONFIG_I2C
-#undef CONFIG_I2C_ARBITRATION
 #undef CONFIG_I2C_DEBUG
 #undef CONFIG_I2C_DEBUG_PASSTHRU
 #undef CONFIG_I2C_PASSTHROUGH
diff --git a/include/i2c_arbitration.h b/include/i2c_arbitration.h
deleted file mode 100644
index cf4d39d247..0000000000
--- a/include/i2c_arbitration.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/* Copyright (c) 2013 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.
- */
-
-/* I2C arbitration for Chrome EC */
-
-#ifndef __CROS_EC_I2C_ARBITRATION_H
-#define __CROS_EC_I2C_ARBITRATION_H
-
-#include "common.h"
-
-#ifdef CONFIG_I2C_ARBITRATION
-
-/**
- * Claim an I2C port for use in master mode.
- *
- * If this function succeeds, you must later call i2c_release() to release the
- * claim.
- *
- * This function must not be called to claim an already-claimed port.
- *
- * @param port	Port to claim (0 for first, 1 for second, etc.)
- * @return 0 if claimed successfully, -1 if it is in use
- */
-int i2c_claim(int port);
-
-/**
- * Release an I2C port (after previously being claimed)
- *
- * This function must not be called to release an already-released port.
- *
- * @param port	Port to claim (0 for first, 1 for second, etc.)
- */
-void i2c_release(int port);
-
-#else
-
-static inline int i2c_claim(int port) { return EC_SUCCESS; }
-static inline void i2c_release(int port) {}
-
-#endif
-
-#endif  /* __CROS_EC_I2C_ARBITRATION_H */