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authorpopcornmix <popcornmix@gmail.com>2013-05-12 12:24:19 +0100
committerpopcornmix <popcornmix@gmail.com>2015-05-18 14:10:14 +0100
commit2d33619dd9633d4b05a615d471a6cfafc061c991 (patch)
tree1dd99883bb17890e19bf4374ac43bba6648b7261 /arch/arm/mach-bcm2708/power.c
parent8b660f48b5734edc272a008a34207cf1a249fcf7 (diff)
downloadlinux-2d33619dd9633d4b05a615d471a6cfafc061c991.tar.gz
Main bcm2708 linux port
Signed-off-by: popcornmix <popcornmix@gmail.com>
Diffstat (limited to 'arch/arm/mach-bcm2708/power.c')
-rw-r--r--arch/arm/mach-bcm2708/power.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/arch/arm/mach-bcm2708/power.c b/arch/arm/mach-bcm2708/power.c
new file mode 100644
index 000000000000..2696be978073
--- /dev/null
+++ b/arch/arm/mach-bcm2708/power.c
@@ -0,0 +1,197 @@
+/*
+ * linux/arch/arm/mach-bcm2708/power.c
+ *
+ * Copyright (C) 2010 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This device provides a shared mechanism for controlling the power to
+ * VideoCore subsystems.
+ */
+
+#include <linux/module.h>
+#include <linux/semaphore.h>
+#include <linux/bug.h>
+#include <mach/power.h>
+#include <mach/vcio.h>
+#include <mach/arm_power.h>
+
+#define DRIVER_NAME "bcm2708_power"
+
+#define BCM_POWER_MAXCLIENTS 4
+#define BCM_POWER_NOCLIENT (1<<31)
+
+/* Some drivers expect there devices to be permanently powered */
+
+#ifdef CONFIG_USB
+#define BCM_POWER_ALWAYS_ON (BCM_POWER_USB)
+#endif
+
+#if 1
+#define DPRINTK printk
+#else
+#define DPRINTK if (0) printk
+#endif
+
+struct state_struct {
+ uint32_t global_request;
+ uint32_t client_request[BCM_POWER_MAXCLIENTS];
+ struct semaphore client_mutex;
+ struct semaphore mutex;
+} g_state;
+
+int bcm_power_open(BCM_POWER_HANDLE_T *handle)
+{
+ BCM_POWER_HANDLE_T i;
+ int ret = -EBUSY;
+
+ down(&g_state.client_mutex);
+
+ for (i = 0; i < BCM_POWER_MAXCLIENTS; i++) {
+ if (g_state.client_request[i] == BCM_POWER_NOCLIENT) {
+ g_state.client_request[i] = BCM_POWER_NONE;
+ *handle = i;
+ ret = 0;
+ break;
+ }
+ }
+
+ up(&g_state.client_mutex);
+
+ DPRINTK("bcm_power_open() -> %d\n", *handle);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(bcm_power_open);
+
+int bcm_power_request(BCM_POWER_HANDLE_T handle, uint32_t request)
+{
+ int rc = 0;
+
+ DPRINTK("bcm_power_request(%d, %x)\n", handle, request);
+
+ if ((handle < BCM_POWER_MAXCLIENTS) &&
+ (g_state.client_request[handle] != BCM_POWER_NOCLIENT)) {
+ if (down_interruptible(&g_state.mutex) != 0) {
+ DPRINTK("bcm_power_request -> interrupted\n");
+ return -EINTR;
+ }
+
+ if (request != g_state.client_request[handle]) {
+ uint32_t others_request = 0;
+ uint32_t global_request;
+ BCM_POWER_HANDLE_T i;
+
+ for (i = 0; i < BCM_POWER_MAXCLIENTS; i++) {
+ if (i != handle)
+ others_request |=
+ g_state.client_request[i];
+ }
+ others_request &= ~BCM_POWER_NOCLIENT;
+
+ global_request = request | others_request;
+ if (global_request != g_state.global_request) {
+ uint32_t actual;
+
+ /* Send a request to VideoCore */
+ bcm_mailbox_write(MBOX_CHAN_POWER,
+ global_request << 4);
+
+ /* Wait for a response during power-up */
+ if (global_request & ~g_state.global_request) {
+ rc = bcm_mailbox_read(MBOX_CHAN_POWER,
+ &actual);
+ DPRINTK
+ ("bcm_mailbox_read -> %08x, %d\n",
+ actual, rc);
+ actual >>= 4;
+ } else {
+ rc = 0;
+ actual = global_request;
+ }
+
+ if (rc == 0) {
+ if (actual != global_request) {
+ printk(KERN_ERR
+ "%s: prev global %x, new global %x, actual %x, request %x, others_request %x\n",
+ __func__,
+ g_state.global_request,
+ global_request, actual, request, others_request);
+ /* A failure */
+ BUG_ON((others_request & actual)
+ != others_request);
+ request &= actual;
+ rc = -EIO;
+ }
+
+ g_state.global_request = actual;
+ g_state.client_request[handle] =
+ request;
+ }
+ }
+ }
+ up(&g_state.mutex);
+ } else {
+ rc = -EINVAL;
+ }
+ DPRINTK("bcm_power_request -> %d\n", rc);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(bcm_power_request);
+
+int bcm_power_close(BCM_POWER_HANDLE_T handle)
+{
+ int rc;
+
+ DPRINTK("bcm_power_close(%d)\n", handle);
+
+ rc = bcm_power_request(handle, BCM_POWER_NONE);
+ if (rc == 0)
+ g_state.client_request[handle] = BCM_POWER_NOCLIENT;
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(bcm_power_close);
+
+static int __init bcm_power_init(void)
+{
+#if defined(BCM_POWER_ALWAYS_ON)
+ BCM_POWER_HANDLE_T always_on_handle;
+#endif
+ int rc = 0;
+ int i;
+
+ printk(KERN_INFO "bcm_power: Broadcom power driver\n");
+ bcm_mailbox_write(MBOX_CHAN_POWER, 0);
+
+ for (i = 0; i < BCM_POWER_MAXCLIENTS; i++)
+ g_state.client_request[i] = BCM_POWER_NOCLIENT;
+
+ sema_init(&g_state.client_mutex, 1);
+ sema_init(&g_state.mutex, 1);
+
+ g_state.global_request = 0;
+
+#if defined(BCM_POWER_ALWAYS_ON)
+ if (BCM_POWER_ALWAYS_ON) {
+ bcm_power_open(&always_on_handle);
+ bcm_power_request(always_on_handle, BCM_POWER_ALWAYS_ON);
+ }
+#endif
+
+ return rc;
+}
+
+static void __exit bcm_power_exit(void)
+{
+ bcm_mailbox_write(MBOX_CHAN_POWER, 0);
+}
+
+arch_initcall(bcm_power_init); /* Initialize early */
+module_exit(bcm_power_exit);
+
+MODULE_AUTHOR("Phil Elwell");
+MODULE_DESCRIPTION("Interface to BCM2708 power management");
+MODULE_LICENSE("GPL");