The current Mailbox framework expects the Mailbox controller
and clients to be backed by Struct devices and uses a DT specific
matching method for clients to lookup channels in a controller.
The helper functions introduced here allow the PCC Mailbox as defined
in the ACPI 5.0+ specification to workaround these expectations and
continue to work with the rest of the Mailbox framework even in the case
where PCC is defined using DT bindings.
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@xxxxxxxxxx>
---
drivers/mailbox/Kconfig | 8 +++
drivers/mailbox/Makefile | 2 +
drivers/mailbox/pcc_mailbox.c | 136 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 146 insertions(+)
create mode 100644 drivers/mailbox/pcc_mailbox.c
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index c8b5c13..0e7be60 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -50,4 +50,12 @@ config OMAP_MBOX_KFIFO_SIZE
Specify the default size of mailbox's kfifo buffers (bytes).
This can also be changed at runtime (via the mbox_kfifo_size
module parameter).
+
+config PCC_MAILBOX_API
+ bool "Platform Communication Channel Mailbox API"
+ help
+ This contains helper functions for registering a PCC mailbox
+ with the generic Mailbox framework and for looking up a PCC
+ channel.
+
endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 2fa343a..3a4f94d 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -9,3 +9,5 @@ obj-$(CONFIG_OMAP1_MBOX) += mailbox_omap1.o
mailbox_omap1-objs := mailbox-omap1.o
obj-$(CONFIG_OMAP2PLUS_MBOX) += mailbox_omap2.o
mailbox_omap2-objs := mailbox-omap2.o
+
+obj-$(CONFIG_PCC_MAILBOX_API) += pcc_mailbox.o
diff --git a/drivers/mailbox/pcc_mailbox.c b/drivers/mailbox/pcc_mailbox.c
new file mode 100644
index 0000000..1454b67
--- /dev/null
+++ b/drivers/mailbox/pcc_mailbox.c
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ * Author: Ashwin Chaugule <ashwin.chaugule@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+
+extern struct list_head mbox_cons;
+extern struct mutex con_mutex;
+extern void mbox_free_channel(struct mbox_chan *chan);
+extern void poll_txdone(unsigned long data);
+
+static struct mbox_controller *pcc_mbox;
+
+struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl, int index)
+{
+ struct mbox_chan *chan;
+ unsigned long flags;
+ int ret;
+
+ if (!pcc_mbox) {
+ pr_err("PCC Mailbox not found.\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ mutex_lock(&con_mutex);
+ /*
+ * Each PCC Subspace is a Mailbox Channel.
+ * The PCC Clients get their PCC Subspace ID
+ * from their own tables and pass it here.
+ * This returns a pointer to the PCC subspace
+ * for the Client to operate on.
+ */
+ chan = &pcc_mbox->chans[index];
+
+ if (!chan || chan->cl || !try_module_get(pcc_mbox->dev->driver->owner)) {
+ pr_err("%s: PCC mailbox not free\n", __func__);
+ mutex_unlock(&con_mutex);
+ return ERR_PTR(-EBUSY);
+ }
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->msg_free = 0;
+ chan->msg_count = 0;
+ chan->active_req = NULL;
+ chan->cl = cl;
+ init_completion(&chan->tx_complete);
+
+ if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
+ chan->txdone_method |= TXDONE_BY_ACK;
+
+ spin_unlock_irqrestore(&chan->lock, flags);
+
+ mutex_unlock(&con_mutex);
+ return chan;
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
+
+void pcc_mbox_free_channel(struct mbox_chan *chan)
+{
+ unsigned long flags;
+
+ if (!chan || !chan->cl)
+ return;
+
+ spin_lock_irqsave(&chan->lock, flags);
+ chan->cl = NULL;
+ chan->active_req = NULL;
+ if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
+ chan->txdone_method = TXDONE_BY_POLL;
+
+ module_put(chan->mbox->dev->driver->owner);
+ spin_unlock_irqrestore(&chan->lock, flags);
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
+
+int pcc_mbox_controller_register(struct mbox_controller *mbox)
+{
+ int i, txdone;
+
+ /* Sanity check */
+ if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans)
+ return -EINVAL;
+
+ if (mbox->txdone_irq)
+ txdone = TXDONE_BY_IRQ;
+ else if (mbox->txdone_poll)
+ txdone = TXDONE_BY_POLL;
+ else /* It has to be ACK then */
+ txdone = TXDONE_BY_ACK;
+
+ if (txdone == TXDONE_BY_POLL) {
+ mbox->poll.function = &poll_txdone;
+ mbox->poll.data = (unsigned long)mbox;
+ init_timer(&mbox->poll);
+ }
+
+ for (i = 0; i < mbox->num_chans; i++) {
+ struct mbox_chan *chan = &mbox->chans[i];
+
+ chan->cl = NULL;
+ chan->mbox = mbox;
+ chan->txdone_method = txdone;
+ spin_lock_init(&chan->lock);
+ }
+
+ mutex_lock(&con_mutex);
+ list_add_tail(&mbox->node, &mbox_cons);
+ /*
+ * Store this so we avoid digging for a PCC mbox in
+ * the Channel lookup.
+ */
+ pcc_mbox = mbox;
+ mutex_unlock(&con_mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_controller_register);
+
--
1.9.1
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