Hi Mollie,
On 13/07/14 07:32, Mollie Wu wrote:
Add driver for the proprietary Mailbox controller (f_mhu) in MB86S7x.
And it looks like this is not Fujitsu proprietary MHU, it's exactly same IP
on JUNO(ARM64 development platform from ARM [1]). I was not sure it's
standard
IP used on other SoCs too, I too wrote similar driver :(.
Can you please confirm this by reading Peripheral ID(PID: 0xFD0, 0xFE0 -
0xFEC) and Component ID(COMPID: 0xFF0 - 0xFFC). Are they
PID - 0x04 0x98 0xB0 0x1B 0x00
COMPID - 0x0D 0xF0 0x05 0xB1
If so we have do s/f_mhu/arm_mhu/g :)
It has three channels - LowPri-NonSecure, HighPri-NonSecure and Secure.
The MB86S7x communicates over the HighPri-NonSecure channel.
Signed-off-by: Jassi Brar <[email protected]>
Signed-off-by: Tetsuya Takinishi <[email protected]>
Signed-off-by: Mollie Wu <[email protected]>
---
drivers/mailbox/Kconfig | 7 ++
drivers/mailbox/Makefile | 2 +
drivers/mailbox/f_mhu.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 236 insertions(+)
create mode 100644 drivers/mailbox/f_mhu.c
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index c8b5c13..681aac2 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -6,6 +6,13 @@ menuconfig MAILBOX
signals. Say Y if your platform supports hardware mailboxes.
if MAILBOX
+
+config MBOX_F_MHU
+ bool
On Juno, there's nothing that prevents me from compiling this as module.
+ depends on ARCH_MB86S7X
Definitely not a requirement
+ help
+ Say Y here if you want to use the F_MHU IPCM support.
+
Also it needs some description.
config PL320_MBOX
bool "ARM PL320 Mailbox"
depends on ARM_AMBA
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 2fa343a..3707e93 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -2,6 +2,8 @@
obj-$(CONFIG_MAILBOX) += mailbox.o
+obj-$(CONFIG_MBOX_F_MHU) += f_mhu.o
+
obj-$(CONFIG_PL320_MBOX) += pl320-ipc.o
obj-$(CONFIG_OMAP_MBOX) += omap-mailbox.o
diff --git a/drivers/mailbox/f_mhu.c b/drivers/mailbox/f_mhu.c
new file mode 100644
index 0000000..cf5d3cd
--- /dev/null
+++ b/drivers/mailbox/f_mhu.c
@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2013-2014 Fujitsu Semiconductor Ltd.
+ *
+ * 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, version 2 of the License.
+ *
+ * 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/delay.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/mailbox_controller.h>
+#include <linux/platform_device.h>
+
+#define INTR_STAT_OFS 0x0
+#define INTR_SET_OFS 0x8
+#define INTR_CLR_OFS 0x10
+
+#define MHU_SCFG 0x400
+
Remove this.(secure access only register)
+struct mhu_link {
+ unsigned irq;
+ spinlock_t lock; /* channel regs */
+ void __iomem *tx_reg;
+ void __iomem *rx_reg;
+};
+
+struct f_mhu {
+ void __iomem *base;
+ struct clk *clk;
+ struct mhu_link mlink[3];
+ struct mbox_chan chan[3];
+ struct mbox_controller mbox;
+};
+
+static irqreturn_t mhu_rx_interrupt(int irq, void *p)
+{
+ struct mbox_chan *chan = (struct mbox_chan *)p;
+ struct mhu_link *mlink = (struct mhu_link *)chan->con_priv;
You don't need explicit cast from void pointers
+ u32 val;
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
Please remove all these debug prints.
+ /* See NOTE_RX_DONE */
+ val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
+ mbox_chan_received_data(chan, (void *)val);
+
+ /*
+ * It is agreed with the remote firmware that the receiver
+ * will clear the STAT register indicating it is ready to
+ * receive next data - NOTE_RX_DONE
+ */
This note could be added as how this mailbox works in general and
it's not just Rx right ? Even Tx done is based on this logic.
Basically the logic is valid on both directions.
+ writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
+
+ return IRQ_HANDLED;
+}
+
+static bool mhu_last_tx_done(struct mbox_chan *chan)
+{
+ struct mhu_link *mlink = (struct mhu_link *)chan->con_priv;
+ unsigned long flags;
+ u32 val;
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ spin_lock_irqsave(&mlink->lock, flags);
Why do we need this extra locks here ? mailbox core maintains
per channel lock and uses it for at-least send_data IIRC. And this
function is just reading status do we really need the lock ?
I must be missing something here else IMO we can get rid of this
extra locks in here.
+ /* See NOTE_RX_DONE */
+ val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+ spin_unlock_irqrestore(&mlink->lock, flags);
+
+ return (val == 0);
+}
+
+static int mhu_send_data(struct mbox_chan *chan, void *data)
+{
+ struct mhu_link *mlink = (struct mhu_link *)chan->con_priv;
+ unsigned long flags;
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ if (!mhu_last_tx_done(chan)) {
+ pr_err("%s:%d Shouldn't have seen the day!\n",
+ __func__, __LINE__);
+ return -EBUSY;
+ }
+
+ spin_lock_irqsave(&mlink->lock, flags);
+ writel_relaxed((u32)data, mlink->tx_reg + INTR_SET_OFS);
+ spin_unlock_irqrestore(&mlink->lock, flags);
+
+ return 0;
+}
+
+static int mhu_startup(struct mbox_chan *chan)
+{
+ struct mhu_link *mlink = (struct mhu_link *)chan->con_priv;
+ unsigned long flags;
+ u32 val;
+ int ret;
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ spin_lock_irqsave(&mlink->lock, flags);
+ val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+ writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
+ spin_unlock_irqrestore(&mlink->lock, flags);
+
+ ret = request_irq(mlink->irq, mhu_rx_interrupt,
+ IRQF_SHARED, "mhu_link", chan);
Just a thought: Can this be threaded_irq instead ?
Can move request_irq to probe instead esp. if threaded_irq ?
That provides some flexibility to client's rx_callback.
+ if (unlikely(ret)) {
+ pr_err("Unable to aquire IRQ\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void mhu_shutdown(struct mbox_chan *chan)
+{
+ struct mhu_link *mlink = (struct mhu_link *)chan->con_priv;
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ free_irq(mlink->irq, chan);
+}
+
+static struct mbox_chan_ops mhu_ops = {
+ .send_data = mhu_send_data,
+ .startup = mhu_startup,
+ .shutdown = mhu_shutdown,
+ .last_tx_done = mhu_last_tx_done,
+};
+
+static int f_mhu_probe(struct platform_device *pdev)
+{
+ int i, err;
+ struct f_mhu *mhu;
+ struct resource *res;
+ int mhu_reg[3] = {0x0, 0x20, 0x200};
Probably this gets simplified when you remove secure channel access ?
+
+ /* Allocate memory for device */
+ mhu = kzalloc(sizeof(*mhu), GFP_KERNEL);
+ if (!mhu) {
+ dev_err(&pdev->dev, "failed to allocate memory.\n");
+ return -EBUSY;
+ }
+
+ mhu->clk = clk_get(&pdev->dev, "clk");
+ if (unlikely(IS_ERR(mhu->clk))) {
+ dev_err(&pdev->dev, "unable to init clock\n");
Don't bail out if there's no clock specified in DT. Clock might not
be a hard requirement.
+ kfree(mhu);
+ return -EINVAL;
+ }
+ clk_prepare_enable(mhu->clk);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mhu->base = ioremap(res->start, resource_size(res));
+ if (!mhu->base) {
+ dev_err(&pdev->dev, "ioremap failed.\n");
+ kfree(mhu);
+ return -EBUSY;
+ }
+
+ /* Let UnTrustedOS's access violations don't bother us */
+ writel_relaxed(0, mhu->base + MHU_SCFG);
+
Please don't do this. It can't work in non-secure mode. The firmware running
with secure access needs to configure this appropriately.
I might be missing to see, is there a binding document for this mhu ?
+ for (i = 0; i < 3; i++) {
+ mhu->chan[i].con_priv = &mhu->mlink[i];
+ spin_lock_init(&mhu->mlink[i].lock);
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
+ mhu->mlink[i].irq = res->start;
+ mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
+ mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + 0x100;
+ }
+
+ mhu->mbox.dev = &pdev->dev;
+ mhu->mbox.chans = &mhu->chan[0];
+ mhu->mbox.num_chans = 3;
Change this to 2, we shouldn't expose secular channel here as Linux can't
access that anyway.
+ mhu->mbox.ops = &mhu_ops;
+ mhu->mbox.txdone_irq = false;
+ mhu->mbox.txdone_poll = true;
+ mhu->mbox.txpoll_period = 10;
+
+ platform_set_drvdata(pdev, mhu);
+
+ err = mbox_controller_register(&mhu->mbox);
+ if (err) {
+ dev_err(&pdev->dev, "Failed to register mailboxes %d\n", err);
+ iounmap(mhu->base);
+ kfree(mhu);
+ } else {
+ dev_info(&pdev->dev, "Fujitsu MHU Mailbox registered\n");
+ }
+
+ return 0;
+}
+
Also to be module you need add remove.
+static const struct of_device_id f_mhu_dt_ids[] = {
+ { .compatible = "fujitsu,mhu" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, f_mhu_dt_ids);
+
+static struct platform_driver f_mhu_driver = {
+ .driver = {
+ .name = "f_mhu",
+ .owner = THIS_MODULE,
+ .of_match_table = f_mhu_dt_ids,
+ },
+ .probe = f_mhu_probe,
+};
+
+static int __init f_mhu_init(void)
+{
+ return platform_driver_register(&f_mhu_driver);
+}
+module_init(f_mhu_init);
This can be module_platform_driver instead.
Regards,
Sudeep
[1]
http://www.arm.com/products/tools/development-boards/versatile-express/juno-arm-development-platform.php
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