[PATCH linux 2/3] drivers/misc: Add aspeed mbox driver
Cyril Bur
cyrilbur at gmail.com
Fri Dec 9 16:43:22 AEDT 2016
Signed-off-by: Cyril Bur <cyrilbur at gmail.com>
---
drivers/misc/Kconfig | 7 +
drivers/misc/Makefile | 2 +
drivers/misc/mbox-host.c | 326 +++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/mbox-host.h | 18 +++
4 files changed, 353 insertions(+)
create mode 100644 drivers/misc/mbox-host.c
create mode 100644 include/uapi/linux/mbox-host.h
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index a216b46..44f191d 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -804,6 +804,13 @@ config PANEL_BOOT_MESSAGE
An empty message will only clear the display at driver init time. Any other
printf()-formatted message is valid with newline and escape codes.
+config MBOX_HOST
+ depends on ARCH_ASPEED
+ bool "Build MBOX driver for BMC to HOST communication"
+ default "n"
+ ---help---
+ Build the MBOX driver
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index b2fb6dbf..7bcaf30 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -57,3 +57,5 @@ obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o
obj-$(CONFIG_CXL_BASE) += cxl/
obj-$(CONFIG_PANEL) += panel.o
+obj-$(CONFIG_MBOX_HOST) += mbox-host.o
+>>>>>>> 6252f95... fixup! drivers/misc: Add aspeed mbox driver
diff --git a/drivers/misc/mbox-host.c b/drivers/misc/mbox-host.c
new file mode 100644
index 0000000..9d11da4
--- /dev/null
+++ b/drivers/misc/mbox-host.c
@@ -0,0 +1,326 @@
+/*
+ * Copyright 2016 IBM Corporation
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/errno.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/miscdevice.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/mbox-host.h>
+
+#define DEVICE_NAME "mbox-host"
+
+#define MBOX_NUM_REGS 16
+#define MBOX_NUM_DATA_REGS 14
+
+#define MBOX_DATA_0 0x00
+#define MBOX_STATUS_0 0x40
+#define MBOX_STATUS_1 0x44
+#define MBOX_BMC_CTRL 0x48
+ #define MBOX_CTRL_RECV 0x80
+ #define MBOX_CTRL_MASK 0x02
+ #define MBOX_CTRL_SEND 0x01
+#define MBOX_HOST_CTRL 0x4c
+#define MBOX_INTERRUPT_0 0x50
+#define MBOX_INTERRUPT_1 0x54
+
+struct mbox_host {
+ struct miscdevice miscdev;
+ void __iomem *base;
+ int irq;
+ wait_queue_head_t queue;
+ struct timer_list poll_timer;
+};
+
+static u8 mbox_inb(struct mbox_host *mbox_host, int reg)
+{
+ return ioread8(mbox_host->base + reg);
+}
+
+static void mbox_outb(struct mbox_host *mbox_host, u8 data, int reg)
+{
+ iowrite8(data, mbox_host->base + reg);
+}
+
+static struct mbox_host *file_mbox_host(struct file *file)
+{
+ return container_of(file->private_data, struct mbox_host, miscdev);
+}
+
+static int mbox_host_open(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static ssize_t mbox_host_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct mbox_host *mbox_host = file_mbox_host(file);
+ char __user *p = buf;
+ int i;
+
+ if (!access_ok(VERIFY_WRITE, buf, count))
+ return -EFAULT;
+
+ WARN_ON(*ppos);
+
+ if (wait_event_interruptible(mbox_host->queue,
+ mbox_inb(mbox_host, MBOX_BMC_CTRL) & MBOX_CTRL_RECV))
+ return -ERESTARTSYS;
+
+ for (i = 0; i < MBOX_NUM_DATA_REGS; i++)
+ if (__put_user(mbox_inb(mbox_host, MBOX_DATA_0 + (i * 4)), p++))
+ return -EFAULT;
+
+ /* MBOX_CTRL_RECV bit is W1C, this also unmasks in 1 step */
+ mbox_outb(mbox_host, MBOX_CTRL_RECV, MBOX_BMC_CTRL);
+ return p - buf;
+}
+
+static ssize_t mbox_host_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct mbox_host *mbox_host = file_mbox_host(file);
+ const char __user *p = buf;
+ char c;
+ int i;
+
+ if (!access_ok(VERIFY_READ, buf, count))
+ return -EFAULT;
+
+ WARN_ON(*ppos);
+
+ for (i = 0; i < MBOX_NUM_DATA_REGS; i++) {
+ if (__get_user(c, p))
+ return -EFAULT;
+
+ mbox_outb(mbox_host, c, MBOX_DATA_0 + (i * 4));
+ p++;
+ }
+
+ mbox_outb(mbox_host, MBOX_CTRL_SEND, MBOX_BMC_CTRL);
+
+ return p - buf;
+}
+
+static long mbox_host_ioctl(struct file *file, unsigned int cmd,
+ unsigned long param)
+{
+ struct mbox_host *mbox_host = file_mbox_host(file);
+
+ switch (cmd) {
+ case MBOX_HOST_IOCTL_ATN:
+ mbox_outb(mbox_host, param, MBOX_DATA_0 + 15);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int mbox_host_release(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static unsigned int mbox_host_poll(struct file *file, poll_table *wait)
+{
+ struct mbox_host *mbox_host = file_mbox_host(file);
+ unsigned int mask = 0;
+
+ poll_wait(file, &mbox_host->queue, wait);
+
+ if (mbox_inb(mbox_host, MBOX_BMC_CTRL) & MBOX_CTRL_RECV)
+ mask |= POLLIN;
+
+ return mask;
+}
+
+static const struct file_operations mbox_host_fops = {
+ .owner = THIS_MODULE,
+ .open = mbox_host_open,
+ .read = mbox_host_read,
+ .write = mbox_host_write,
+ .release = mbox_host_release,
+ .poll = mbox_host_poll,
+ .unlocked_ioctl = mbox_host_ioctl,
+};
+
+static void poll_timer(unsigned long data)
+{
+ struct mbox_host *mbox_host = (void *)data;
+
+ mbox_host->poll_timer.expires += msecs_to_jiffies(500);
+ wake_up(&mbox_host->queue);
+ add_timer(&mbox_host->poll_timer);
+}
+
+static irqreturn_t mbox_host_irq(int irq, void *arg)
+{
+ struct mbox_host *mbox_host = arg;
+
+ if (!(mbox_inb(mbox_host, MBOX_BMC_CTRL) & MBOX_CTRL_RECV))
+ return IRQ_NONE;
+
+ /*
+ * Leave the status bit set so that we know the data is for us,
+ * clear it once it has been read.
+ */
+
+ /* Mask it off, we'll clear it when we the data gets read */
+ mbox_outb(mbox_host, MBOX_CTRL_MASK, MBOX_BMC_CTRL);
+
+ wake_up(&mbox_host->queue);
+ return IRQ_HANDLED;
+}
+
+static int mbox_host_config_irq(struct mbox_host *mbox_host,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int rc;
+
+ mbox_host->irq = irq_of_parse_and_map(dev->of_node, 0);
+ if (!mbox_host->irq)
+ return -ENODEV;
+
+ rc = devm_request_irq(dev, mbox_host->irq, mbox_host_irq, IRQF_SHARED,
+ DEVICE_NAME, mbox_host);
+ if (rc < 0) {
+ dev_warn(dev, "Unable to request IRQ %d\n", mbox_host->irq);
+ mbox_host->irq = 0;
+ return rc;
+ }
+
+ /*
+ * Disable all register based interrupts, we'll have to change
+ * this, protocol seemingly will require regs 0 and 15
+ */
+ mbox_outb(mbox_host, 0x00, MBOX_INTERRUPT_0); /* regs 0 - 7 */
+ mbox_outb(mbox_host, 0x00, MBOX_INTERRUPT_1); /* regs 8 - 15 */
+
+ /* W1C */
+ mbox_outb(mbox_host, 0xff, MBOX_STATUS_0);
+ mbox_outb(mbox_host, 0xff, MBOX_STATUS_1);
+
+ mbox_outb(mbox_host, MBOX_CTRL_RECV, MBOX_BMC_CTRL);
+ return 0;
+}
+
+static int mbox_host_probe(struct platform_device *pdev)
+{
+ struct mbox_host *mbox_host;
+ struct device *dev;
+ struct resource *res;
+ int rc;
+
+ if (!pdev || !pdev->dev.of_node)
+ return -ENODEV;
+
+ dev = &pdev->dev;
+ dev_info(dev, "Found mbox host device\n");
+
+ mbox_host = devm_kzalloc(dev, sizeof(*mbox_host), GFP_KERNEL);
+ if (!mbox_host)
+ return -ENOMEM;
+
+ dev_set_drvdata(&pdev->dev, mbox_host);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "Unable to find resources\n");
+ rc = -ENXIO;
+ goto out_free;
+ }
+
+ mbox_host->base = devm_ioremap_resource(&pdev->dev, res);
+ if (!mbox_host->base) {
+ rc = -ENOMEM;
+ goto out_free;
+ }
+ init_waitqueue_head(&mbox_host->queue);
+
+ mbox_host->miscdev.minor = MISC_DYNAMIC_MINOR;
+ mbox_host->miscdev.name = DEVICE_NAME;
+ mbox_host->miscdev.fops = &mbox_host_fops;
+ mbox_host->miscdev.parent = dev;
+ rc = misc_register(&mbox_host->miscdev);
+ if (rc) {
+ dev_err(dev, "Unable to register device\n");
+ goto out_unmap;
+ }
+
+ mbox_host_config_irq(mbox_host, pdev);
+
+ if (mbox_host->irq) {
+ dev_info(dev, "Using IRQ %d\n", mbox_host->irq);
+ } else {
+ dev_info(dev, "No IRQ; using timer\n");
+ setup_timer(&mbox_host->poll_timer, poll_timer,
+ (unsigned long)mbox_host);
+ mbox_host->poll_timer.expires = jiffies + msecs_to_jiffies(10);
+ add_timer(&mbox_host->poll_timer);
+ }
+ return 0;
+
+out_unmap:
+ devm_iounmap(&pdev->dev, mbox_host->base);
+
+out_free:
+ devm_kfree(dev, mbox_host);
+ return rc;
+
+}
+
+static int mbox_host_remove(struct platform_device *pdev)
+{
+ struct mbox_host *mbox_host = dev_get_drvdata(&pdev->dev);
+
+ misc_deregister(&mbox_host->miscdev);
+ if (!mbox_host->irq)
+ del_timer_sync(&mbox_host->poll_timer);
+ devm_iounmap(&pdev->dev, mbox_host->base);
+ devm_kfree(&pdev->dev, mbox_host);
+ mbox_host = NULL;
+
+ return 0;
+}
+
+static const struct of_device_id mbox_host_match[] = {
+ { .compatible = "aspeed,mbox-host" },
+ { },
+};
+
+static struct platform_driver mbox_host_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = mbox_host_match,
+ },
+ .probe = mbox_host_probe,
+ .remove = mbox_host_remove,
+};
+
+module_platform_driver(mbox_host_driver);
+
+MODULE_DEVICE_TABLE(of, mbox_host_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cyril Bur <cyrilbur at gmail.com>");
+MODULE_DESCRIPTION("Linux device interface to the MBOX interface");
diff --git a/include/uapi/linux/mbox-host.h b/include/uapi/linux/mbox-host.h
new file mode 100644
index 0000000..3888f43
--- /dev/null
+++ b/include/uapi/linux/mbox-host.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright 2016 IBM Corp.
+ *
+ * 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.
+ */
+
+#ifndef _UAPI_LINUX_MBOX_HOST_H
+#define _UAPI_LINUX_MBOX_HOST_H
+
+#include <linux/ioctl.h>
+
+#define __MBOX_HOST_IOCTL_MAGIC 0xb1
+#define MBOX_HOST_IOCTL_ATN _IOW(__MBOX_HOST_IOCTL_MAGIC, 0x00, uint8_t)
+
+#endif /* _UAPI_LINUX_MBOX_HOST_H */
--
2.10.2
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