Change one-wire bus to use normal gpio interface

There's no need for it to directly access the GPIO registers.  That
was only necessary at the beginning of link, when gpio_set_flags()
didn't exist.

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: I2386962ff039bb2251be38eaadcaeae8ffd1ea7b
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/64375
Reviewed-by: Vic Yang <victoryang@chromium.org>

6 files changed, 9 insertions, 38 deletions

diff --git a/board/bolt/board.c b/board/bolt/board.c
index c567749bff..ccdc8bce87 100644
--- a/board/bolt/board.c
+++ b/board/bolt/board.c
@@ -70,6 +70,7 @@ const struct gpio_info gpio_list[] = {
 	{"BOARD_VERSION2",       LM4_GPIO_Q, (1<<6), GPIO_INPUT, NULL},
 	{"BOARD_VERSION3",       LM4_GPIO_Q, (1<<7), GPIO_INPUT, NULL},
 	{"CPU_PGOOD",            LM4_GPIO_C, (1<<4), GPIO_INPUT, NULL},
+	{"ONEWIRE",              LM4_GPIO_F, (1<<7), GPIO_INPUT, NULL},
 	{"PCH_CATERR_L",         LM4_GPIO_F, (1<<3), GPIO_INPUT, NULL},
 	{"THERMAL_DATA_READY_L", LM4_GPIO_B, (1<<0), GPIO_INPUT, NULL},
 	{"USB1_OC_L",            LM4_GPIO_E, (1<<7), GPIO_INPUT, NULL},
diff --git a/board/bolt/board.h b/board/bolt/board.h
index 36e274011d..3fed8c42f4 100644
--- a/board/bolt/board.h
+++ b/board/bolt/board.h
@@ -26,8 +26,6 @@
 #endif
 #define CONFIG_LED_DRIVER_DS2413
 #define CONFIG_ONEWIRE
-#define CONFIG_ONEWIRE_BANK LM4_GPIO_F
-#define CONFIG_ONEWIRE_PIN (1 << 7)
 #define CONFIG_POWER_BUTTON
 #define CONFIG_POWER_BUTTON_X86
 #define CONFIG_WP_ACTIVE_HIGH
@@ -104,6 +102,7 @@ enum gpio_signal {
 	GPIO_BOARD_VERSION2,       /* Board version stuffing resistor 2 */
 	GPIO_BOARD_VERSION3,       /* Board version stuffing resistor 3 */
 	GPIO_CPU_PGOOD,            /* Power good to the CPU */
+	GPIO_ONEWIRE,              /* One-wire bus to adapter LED */
 	GPIO_PCH_CATERR_L,         /* Catastrophic error signal from PCH */
 	GPIO_THERMAL_DATA_READY_L, /* From thermal sensor */
 	GPIO_USB1_OC_L,            /* USB port overcurrent warning */
diff --git a/board/link/board.c b/board/link/board.c
index b4fa8818b4..cfcc695ecd 100644
--- a/board/link/board.c
+++ b/board/link/board.c
@@ -41,6 +41,7 @@ const struct gpio_info gpio_list[] = {
 	{"BOARD_VERSION1",       LM4_GPIO_H, (1<<6), 0, NULL},
 	{"BOARD_VERSION2",       LM4_GPIO_L, (1<<6), 0, NULL},
 	{"BOARD_VERSION3",       LM4_GPIO_L, (1<<7), 0, NULL},
+	{"ONEWIRE",              LM4_GPIO_H, (1<<2), 0, NULL},
 	{"PCH_BKLTEN",           LM4_GPIO_J, (1<<3), GPIO_INT_BOTH,
 	 backlight_interrupt},
 	{"PCH_SLP_A_L",          LM4_GPIO_G, (1<<5), GPIO_INT_BOTH,
diff --git a/board/link/board.h b/board/link/board.h
index 422db1dfcd..ea6d2f1f62 100644
--- a/board/link/board.h
+++ b/board/link/board.h
@@ -26,8 +26,6 @@
 #endif
 #define CONFIG_LED_DRIVER_DS2413
 #define CONFIG_ONEWIRE
-#define CONFIG_ONEWIRE_BANK LM4_GPIO_H
-#define CONFIG_ONEWIRE_PIN (1 << 2)
 #define CONFIG_POWER_BUTTON
 #define CONFIG_POWER_BUTTON_X86
 #define CONFIG_PWM_FAN
@@ -95,6 +93,7 @@ enum gpio_signal {
 	GPIO_BOARD_VERSION1,       /* Board version stuffing resistor 1 */
 	GPIO_BOARD_VERSION2,       /* Board version stuffing resistor 2 */
 	GPIO_BOARD_VERSION3,       /* Board version stuffing resistor 3 */
+	GPIO_ONEWIRE,              /* One-wire bus to adapter LED */
 	GPIO_PCH_BKLTEN,           /* Backlight enable signal from PCH */
 	GPIO_PCH_SLP_A_L,          /* SLP_A# signal from PCH */
 	GPIO_PCH_SLP_ME_CSW_DEV_L, /* SLP_ME_CSW_DEV# signal from PCH */
diff --git a/chip/lm4/onewire.c b/chip/lm4/onewire.c
index 1147314b6b..e57d6db5a1 100644
--- a/chip/lm4/onewire.c
+++ b/chip/lm4/onewire.c
@@ -7,15 +7,9 @@
 
 #include "common.h"
 #include "gpio.h"
-#include "hooks.h"
-#include "registers.h"
 #include "task.h"
 #include "timer.h"
 
-#if !defined(CONFIG_ONEWIRE_BANK) || !defined(CONFIG_ONEWIRE_PIN)
-#error Unsupported board. CONFIG_ONEWIRE_BANK/PIN need to be defined.
-#endif
-
 /*
  * Standard speed; all timings padded by 2 usec for safety.
  *
@@ -38,18 +32,10 @@
  */
 static void output0(int usec)
 {
-	LM4_GPIO_DIR(CONFIG_ONEWIRE_BANK) |= CONFIG_ONEWIRE_PIN;
-	LM4_GPIO_DATA(CONFIG_ONEWIRE_BANK, CONFIG_ONEWIRE_PIN) = 0;
+	gpio_set_flags(GPIO_ONEWIRE,
+		       GPIO_OPEN_DRAIN | GPIO_OUTPUT | GPIO_OUT_LOW);
 	udelay(usec);
-	LM4_GPIO_DIR(CONFIG_ONEWIRE_BANK) &= ~CONFIG_ONEWIRE_PIN;
-}
-
-/**
- *  Read the signal line.
- */
-static int readline(void)
-{
-	return LM4_GPIO_DATA(CONFIG_ONEWIRE_BANK, CONFIG_ONEWIRE_PIN) ? 1 : 0;
+	gpio_set_flags(GPIO_ONEWIRE, GPIO_INPUT);
 }
 
 /**
@@ -72,7 +58,7 @@ static int readbit(void)
 	udelay(T_MSR - T_RL);
 
 	/* Read bit */
-	bit = readline();
+	bit = gpio_get_level(GPIO_ONEWIRE);
 
 	/*
 	 * Enable interrupt as soon as we've read the bit.  The delay to the
@@ -125,7 +111,7 @@ int onewire_reset(void)
 	 */
 	udelay(T_MSP);
 
-	if (readline() != 0)
+	if (gpio_get_level(GPIO_ONEWIRE))
 		return EC_ERROR_UNKNOWN;
 
 	/*
@@ -156,12 +142,3 @@ void onewire_write(int data)
 	for (i = 0; i < 8; i++)
 		writebit((data >> i) & 0x01);  /* LSB first */
 }
-
-static void onewire_init(void)
-{
-	/* Configure 1-wire pin as open-drain GPIO */
-	gpio_set_alternate_function(CONFIG_ONEWIRE_BANK,
-				    CONFIG_ONEWIRE_PIN, -1);
-	LM4_GPIO_ODR(CONFIG_ONEWIRE_BANK) |= CONFIG_ONEWIRE_PIN;
-}
-DECLARE_HOOK(HOOK_INIT, onewire_init, HOOK_PRIO_DEFAULT);
diff --git a/include/config.h b/include/config.h
index f86ab58a17..219a2c82bc 100644
--- a/include/config.h
+++ b/include/config.h
@@ -403,12 +403,6 @@
 /* Compile support for one-wire interface */
 #undef CONFIG_ONEWIRE
 
-/* GPIO bank for one-wire interface */
-#undef CONFIG_ONEWIRE_BANK
-
-/* Pin mask for one-wire interface */
-#undef CONFIG_ONEWIRE_PIN
-
 /* Check for stack overflows on every context switch */
 #undef CONFIG_OVERFLOW_DETECT