Add hooks module so modules can be notified of system-level events.

This will be used for sleep/wake/sysjump/etc.  For now it's just wired
up to clock frequency changing.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

BUG=none
TEST=manual: use nopll command, should still work

Change-Id: Iedcea5830bc18eacfd955c29b8f793aba8905dd8

5 files changed, 63 insertions, 33 deletions

diff --git a/include/hooks.h b/include/hooks.h
new file mode 100644
index 0000000000..3d3a834e25
--- /dev/null
+++ b/include/hooks.h
@@ -0,0 +1,48 @@
+/* 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.
+ */
+
+/* System hooks for Chrome EC */
+
+#ifndef __CROS_EC_HOOKS_H
+#define __CROS_EC_HOOKS_H
+
+#include "common.h"
+
+enum hook_priority {
+	HOOK_PRIO_FIRST = 1,       /* Highest priority */
+	HOOK_PRIO_DEFAULT = 5000,  /* Default priority */
+	HOOK_PRIO_LAST = 9999      /* Lowest priority */
+};
+
+enum hook_type {
+	HOOK_FREQ_CHANGE,  /* System clock changed frequency */
+};
+
+
+struct hook_data {
+	/* Hook processing routine; returns EC error code. */
+	int (*routine)(void);
+	/* Priority; low numbers = higher priority. */
+	int priority;
+};
+
+
+/* Call all the hook routines of a specified type.  If stop_on_error, stops on
+ * the first non-EC_SUCCESS return code.  Returns the first non-EC_SUCCESS
+ * return code, if any, or EC_SUCCESS if all hooks returned EC_SUCCESS. */
+int hook_notify(enum hook_type type, int stop_on_error);
+
+
+/* Register a hook routine.  <hooktype> should be one of enum hook_type.
+ * <routine> should be int routine(void), and should return an error code or
+ * EC_SUCCESS if no error.  <priority> should be between HOOK_PRIO_FIRST and
+ * HOOK_PRIO_LAST, and should be HOOK_PRIO_DEFAULT unless there's a compelling
+ * reason to care about the order in which hooks are called. */
+#define DECLARE_HOOK(hooktype, routine, priority)			\
+	const struct hook_data __hook_##hooktype##_##routine		\
+	__attribute__((section(".rodata." #hooktype)))			\
+	     = {routine, priority}
+
+#endif  /* __CROS_EC_HOOKS_H */
diff --git a/include/hwtimer.h b/include/hwtimer.h
index 5fee466b7c..ae0c634163 100644
--- a/include/hwtimer.h
+++ b/include/hwtimer.h
@@ -5,8 +5,8 @@
 
 /* Hardware timer driver API */
 
-#ifndef __EC_HWTIMER_H
-#define __EC_HWTIMER_H
+#ifndef __CROS_EC_HWTIMER_H
+#define __CROS_EC_HWTIMER_H
 
 /**
  * Programs when the next timer should fire an interrupt.
@@ -30,9 +30,6 @@ uint32_t __hw_clock_source_read(void);
  */
 int __hw_clock_source_init(void);
 
-/* Notifies the module the system clock frequency has changed to <freq>. */
-void hwtimer_clock_changed(int freq);
-
 /**
  * Searches the next deadline and program it in the timer hardware.
  *
@@ -43,4 +40,4 @@ void hwtimer_clock_changed(int freq);
  */
 void process_timers(int overflow);
 
-#endif  /* __EC_HWTIMER_H */
+#endif  /* __CROS_EC_HWTIMER_H */
diff --git a/include/i2c.h b/include/i2c.h
index 22ab18adcf..7543d8cb25 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -13,30 +13,23 @@
 /* Flags for slave address field, in addition to the 8-bit address */
 #define I2C_FLAG_BIG_ENDIAN 0x100  /* 16 byte values are MSB-first */
 
-/* Initializes the module. */
+/* Initialize the module. */
 int i2c_init(void);
 
-/* Notifies the module the system clock frequency has changed to <freq>. */
-void i2c_clock_changed(int freq);
-
-/* Reads a 16-bit register from the slave at 8-bit slave address
- * <slaveaddr>, at the specified 8-bit <offset> in the slave's address
- * space. */
+/* Read a 16-bit register from the slave at 8-bit slave address <slaveaddr>, at
+ * the specified 8-bit <offset> in the slave's address space. */
 int i2c_read16(int port, int slave_addr, int offset, int* data);
 
-/* Writes a 16-bit register to the slave at 8-bit slave address
- * <slaveaddr>, at the specified 8-bit <offset> in the slave's address
- * space. */
+/* Write a 16-bit register to the slave at 8-bit slave address <slaveaddr>, at
+ * the specified 8-bit <offset> in the slave's address space. */
 int i2c_write16(int port, int slave_addr, int offset, int data);
 
-/* Reads an 8-bit register from the slave at 8-bit slave address
- * <slaveaddr>, at the specified 8-bit <offset> in the slave's address
- * space. */
+/* Read an 8-bit register from the slave at 8-bit slave address <slaveaddr>, at
+ * the specified 8-bit <offset> in the slave's address space. */
 int i2c_read8(int port, int slave_addr, int offset, int* data);
 
-/* Writes an 8-bit register to the slave at 8-bit slave address
- * <slaveaddr>, at the specified 8-bit <offset> in the slave's address
- * space. */
+/* Write an 8-bit register to the slave at 8-bit slave address <slaveaddr>, at
+ * the specified 8-bit <offset> in the slave's address space. */
 int i2c_write8(int port, int slave_addr, int offset, int data);
 
 /* Read ascii string using smbus read block protocol.
diff --git a/include/peci.h b/include/peci.h
index 7a98a24991..1ad0d92bad 100644
--- a/include/peci.h
+++ b/include/peci.h
@@ -10,21 +10,16 @@
 
 #include "common.h"
 
-struct temp_sensor_t;
-
-/* Initializes the module. */
+/* Initialize the module. */
 int peci_init(void);
 
-/* Notifies the module the system clock frequency has changed to <freq>. */
-void peci_clock_changed(int freq);
-
-/* Returns the current CPU temperature in degrees K, or -1 if error.
+/* Return the current CPU temperature in degrees K, or -1 if error.
  *
  * Note that the PECI interface is currently a little flaky; if you get an
  * error, retry a bit later. */
 int peci_get_cpu_temp(void);
 
-/* Reads the CPU temperature sensor via PECI.  This interface is for the
+/* Read the CPU temperature sensor via PECI.  This interface is for the
  * temperature sensor module.  Returns the temperature in degrees K, or -1 if
  * error. */
 int peci_temp_sensor_get_val(int idx);
diff --git a/include/watchdog.h b/include/watchdog.h
index 569352bc6a..68ac7b917e 100644
--- a/include/watchdog.h
+++ b/include/watchdog.h
@@ -15,7 +15,4 @@ int watchdog_init(int period_ms);
 /* Reload the watchdog counter */
 void watchdog_reload(void);
 
-/* Notifies the module the system clock frequency has changed to <freq>. */
-void watchdog_clock_changed(int freq);
-
 #endif /* __CROS_EC_WATCHDOG_H */