Move onewire bus support from chip/lm4 to common

No functional changes; just moving file

BUG=chrome-os-partner:21612
BRANCH=none
TEST=onewire red / onewire green / onewire yellow all set the adapter LED
     (tested on link, since I don't have a bolt, but the EC chip and adapter
     are identical)

Change-Id: I005abf871caafa39e82e88875b515c842a12d591
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/64376
Reviewed-by: Vic Yang <victoryang@chromium.org>

2 files changed, 0 insertions, 145 deletions

diff --git a/chip/lm4/build.mk b/chip/lm4/build.mk
index d9114a072e..0125ada892 100644
--- a/chip/lm4/build.mk
+++ b/chip/lm4/build.mk
@@ -18,7 +18,6 @@ chip-$(CONFIG_EEPROM)+=eeprom.o
 chip-$(CONFIG_FLASH)+=flash.o
 chip-$(CONFIG_I2C)+=i2c.o
 chip-$(CONFIG_LPC)+=lpc.o
-chip-$(CONFIG_ONEWIRE)+=onewire.o
 chip-$(CONFIG_PECI)+=peci.o
 chip-$(CONFIG_PWM_FAN)+=pwm_fan.o
 chip-$(CONFIG_PWM_KBLIGHT)+=pwm_kblight.o
diff --git a/chip/lm4/onewire.c b/chip/lm4/onewire.c
deleted file mode 100644
index e57d6db5a1..0000000000
--- a/chip/lm4/onewire.c
+++ /dev/null
@@ -1,144 +0,0 @@
-/* Copyright (c) 2012 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.
- */
-
-/* 1-wire interface module for Chrome EC */
-
-#include "common.h"
-#include "gpio.h"
-#include "task.h"
-#include "timer.h"
-
-/*
- * Standard speed; all timings padded by 2 usec for safety.
- *
- * Note that these timing are actually _longer_ than legacy 1-wire standard
- * speed because we're running the 1-wire bus at 3.3V instead of 5V.
- */
-#define T_RSTL 602  /* Reset low pulse; 600-960 us */
-#define T_MSP   72  /* Presence detect sample time; 70-75 us */
-#define T_RSTH (68 + 260 + 5 + 2) /* Reset high; tPDHmax + tPDLmax + tRECmin */
-#define T_SLOT  70  /* Timeslot; >67 us */
-#define T_W0L   63  /* Write 0 low; 62-120 us */
-#define T_W1L    7  /* Write 1 low; 5-15 us */
-#define T_RL     7  /* Read low; 5-15 us */
-#define T_MSR    9  /* Read sample time; <15 us.  Must be at least 200 ns after
-		     * T_RL since that's how long the signal takes to be pulled
-		     * up on our board.  */
-
-/**
- * Output low on the bus for <usec> us, then switch back to open-drain input.
- */
-static void output0(int usec)
-{
-	gpio_set_flags(GPIO_ONEWIRE,
-		       GPIO_OPEN_DRAIN | GPIO_OUTPUT | GPIO_OUT_LOW);
-	udelay(usec);
-	gpio_set_flags(GPIO_ONEWIRE, GPIO_INPUT);
-}
-
-/**
- * Read a bit.
- */
-static int readbit(void)
-{
-	int bit;
-
-	/*
-	 * The delay between sending the output pulse and reading the bit is
-	 * extremely timing sensitive, so disable interrupts.
-	 */
-	interrupt_disable();
-
-	/* Output low */
-	output0(T_RL);
-
-	/* Delay to let slave release the line if it wants to send a 1-bit */
-	udelay(T_MSR - T_RL);
-
-	/* Read bit */
-	bit = gpio_get_level(GPIO_ONEWIRE);
-
-	/*
-	 * Enable interrupt as soon as we've read the bit.  The delay to the
-	 * end of the timeslot is a lower bound, so additional latency here is
-	 * harmless.
-	 */
-	interrupt_enable();
-
-	/* Delay to end of timeslot */
-	udelay(T_SLOT - T_MSR);
-	return bit;
-}
-
-/**
- * Write a bit.
- */
-static void writebit(int bit)
-{
-	/*
-	 * The delays in the output-low signal for sending 0 and 1 bits are
-	 * extremely timing sensitive, so disable interrupts during that time.
-	 * Interrupts can be enabled again as soon as the output is switched
-	 * back to open-drain, since the delay for the rest of the timeslot is
-	 * a lower bound.
-	 */
-	if (bit) {
-		interrupt_disable();
-		output0(T_W1L);
-		interrupt_enable();
-		udelay(T_SLOT - T_W1L);
-	} else {
-		interrupt_disable();
-		output0(T_W0L);
-		interrupt_enable();
-		udelay(T_SLOT - T_W0L);
-	}
-
-}
-
-int onewire_reset(void)
-{
-	/* Start transaction with master reset pulse */
-	output0(T_RSTL);
-
-	/* Wait for presence detect sample time.
-	 *
-	 * (Alternately, we could poll waiting for a 1-bit indicating our pulse
-	 * has let go, then poll up to max time waiting for a 0-bit indicating
-	 * the slave has responded.)
-	 */
-	udelay(T_MSP);
-
-	if (gpio_get_level(GPIO_ONEWIRE))
-		return EC_ERROR_UNKNOWN;
-
-	/*
-	 * Wait for end of presence pulse.
-	 *
-	 * (Alternately, we could poll waiting for a 1-bit.)
-	 */
-	udelay(T_RSTH - T_MSP);
-
-	return EC_SUCCESS;
-}
-
-int onewire_read(void)
-{
-	int data = 0;
-	int i;
-
-	for (i = 0; i < 8; i++)
-		data |= readbit() << i;  /* LSB first */
-
-	return data;
-}
-
-void onewire_write(int data)
-{
-	int i;
-
-	for (i = 0; i < 8; i++)
-		writebit((data >> i) & 0x01);  /* LSB first */
-}