[PATCH v2 1/2] soc: aspeed: Add LPC mailbox support
Chia-Wei Wang
chiawei_wang at aspeedtech.com
Tue Aug 17 12:58:47 AEST 2021
The LPC mailbox controller consists of multiple general
registers for the communication between the Host and the BMC.
The interrupts for data update signaling are also introduced.
Signed-off-by: Chia-Wei Wang <chiawei_wang at aspeedtech.com>
Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
---
drivers/soc/aspeed/Kconfig | 10 +
drivers/soc/aspeed/Makefile | 9 +-
drivers/soc/aspeed/aspeed-lpc-mbox.c | 418 +++++++++++++++++++++++++++
3 files changed, 433 insertions(+), 4 deletions(-)
create mode 100644 drivers/soc/aspeed/aspeed-lpc-mbox.c
diff --git a/drivers/soc/aspeed/Kconfig b/drivers/soc/aspeed/Kconfig
index 243ca196e6ad..5b31a6e2620c 100644
--- a/drivers/soc/aspeed/Kconfig
+++ b/drivers/soc/aspeed/Kconfig
@@ -24,6 +24,16 @@ config ASPEED_LPC_SNOOP
allows the BMC to listen on and save the data written by
the host to an arbitrary LPC I/O port.
+config ASPEED_LPC_MAILBOX
+ tristate "ASPEED LPC mailbox support"
+ select REGMAP
+ select MFD_SYSCON
+ default ARCH_ASPEED
+ help
+ Provides a driver to control the LPC mailbox which possesses
+ up to 32 data registers for the communication between the Host
+ and the BMC over LPC.
+
config ASPEED_P2A_CTRL
tristate "ASPEED P2A (VGA MMIO to BMC) bridge control"
select REGMAP
diff --git a/drivers/soc/aspeed/Makefile b/drivers/soc/aspeed/Makefile
index fcab7192e1a4..cde6b4514c97 100644
--- a/drivers/soc/aspeed/Makefile
+++ b/drivers/soc/aspeed/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
-obj-$(CONFIG_ASPEED_LPC_CTRL) += aspeed-lpc-ctrl.o
-obj-$(CONFIG_ASPEED_LPC_SNOOP) += aspeed-lpc-snoop.o
-obj-$(CONFIG_ASPEED_P2A_CTRL) += aspeed-p2a-ctrl.o
-obj-$(CONFIG_ASPEED_SOCINFO) += aspeed-socinfo.o
+obj-$(CONFIG_ASPEED_LPC_CTRL) += aspeed-lpc-ctrl.o
+obj-$(CONFIG_ASPEED_LPC_SNOOP) += aspeed-lpc-snoop.o
+obj-$(CONFIG_ASPEED_LPC_MAILBOX) += aspeed-lpc-mbox.o
+obj-$(CONFIG_ASPEED_P2A_CTRL) += aspeed-p2a-ctrl.o
+obj-$(CONFIG_ASPEED_SOCINFO) += aspeed-socinfo.o
diff --git a/drivers/soc/aspeed/aspeed-lpc-mbox.c b/drivers/soc/aspeed/aspeed-lpc-mbox.c
new file mode 100644
index 000000000000..a09ca6a175f7
--- /dev/null
+++ b/drivers/soc/aspeed/aspeed-lpc-mbox.c
@@ -0,0 +1,418 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2017 IBM Corporation
+ * Copyright 2021 Aspeed Technology Inc.
+ */
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define DEVICE_NAME "aspeed-mbox"
+
+#define ASPEED_MBOX_DR(dr, n) (dr + (n * 4))
+#define ASPEED_MBOX_STR(str, n) (str + (n / 8) * 4)
+#define ASPEED_MBOX_BIE(bie, n) (bie + (n / 8) * 4)
+#define ASPEED_MBOX_HIE(hie, n) (hie + (n / 8) * 4)
+
+#define ASPEED_MBOX_BCR_RECV BIT(7)
+#define ASPEED_MBOX_BCR_MASK BIT(1)
+#define ASPEED_MBOX_BCR_SEND BIT(0)
+
+/* ioctl code */
+#define ASPEED_MBOX_IOCTL 0xA3
+#define ASPEED_MBOX_IOCTL_GET_SIZE \
+ _IOR(ASPEED_MBOX_IOCTL, 0, struct aspeed_mbox_ioctl_data)
+
+struct aspeed_mbox_ioctl_data {
+ unsigned int data;
+};
+
+struct aspeed_mbox_model {
+ unsigned int dr_num;
+
+ /* offsets to the MBOX registers */
+ unsigned int dr;
+ unsigned int str;
+ unsigned int bcr;
+ unsigned int hcr;
+ unsigned int bie;
+ unsigned int hie;
+};
+
+struct aspeed_mbox {
+ struct miscdevice miscdev;
+ struct regmap *map;
+ unsigned int base;
+ wait_queue_head_t queue;
+ struct mutex mutex;
+ const struct aspeed_mbox_model *model;
+};
+
+static atomic_t aspeed_mbox_open_count = ATOMIC_INIT(0);
+
+static u8 aspeed_mbox_inb(struct aspeed_mbox *mbox, int reg)
+{
+ /*
+ * The mbox registers are actually only one byte but are addressed
+ * four bytes apart. The other three bytes are marked 'reserved',
+ * they *should* be zero but lets not rely on it.
+ * I am going to rely on the fact we can casually read/write to them...
+ */
+ unsigned int val = 0xff; /* If regmap throws an error return 0xff */
+ int rc = regmap_read(mbox->map, mbox->base + reg, &val);
+
+ if (rc)
+ dev_err(mbox->miscdev.parent, "regmap_read() failed with "
+ "%d (reg: 0x%08x)\n", rc, reg);
+
+ return val & 0xff;
+}
+
+static void aspeed_mbox_outb(struct aspeed_mbox *mbox, u8 data, int reg)
+{
+ int rc = regmap_write(mbox->map, mbox->base + reg, data);
+
+ if (rc)
+ dev_err(mbox->miscdev.parent, "regmap_write() failed with "
+ "%d (data: %u reg: 0x%08x)\n", rc, data, reg);
+}
+
+static struct aspeed_mbox *file_mbox(struct file *file)
+{
+ return container_of(file->private_data, struct aspeed_mbox, miscdev);
+}
+
+static int aspeed_mbox_open(struct inode *inode, struct file *file)
+{
+ struct aspeed_mbox *mbox = file_mbox(file);
+ const struct aspeed_mbox_model *model = mbox->model;
+
+ if (atomic_inc_return(&aspeed_mbox_open_count) == 1) {
+ /*
+ * Clear the interrupt status bit if it was left on and unmask
+ * interrupts.
+ * ASPEED_MBOX_BCR_RECV bit is W1C, this also unmasks in 1 step
+ */
+ aspeed_mbox_outb(mbox, ASPEED_MBOX_BCR_RECV, model->bcr);
+ return 0;
+ }
+
+ atomic_dec(&aspeed_mbox_open_count);
+ return -EBUSY;
+}
+
+static ssize_t aspeed_mbox_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct aspeed_mbox *mbox = file_mbox(file);
+ const struct aspeed_mbox_model *model = mbox->model;
+ char __user *p = buf;
+ ssize_t ret;
+ int i;
+
+ if (!access_ok(buf, count))
+ return -EFAULT;
+
+ if (count + *ppos > model->dr_num)
+ return -EINVAL;
+
+ if (file->f_flags & O_NONBLOCK) {
+ if (!(aspeed_mbox_inb(mbox, model->bcr) &
+ ASPEED_MBOX_BCR_RECV))
+ return -EAGAIN;
+ } else if (wait_event_interruptible(mbox->queue,
+ aspeed_mbox_inb(mbox, model->bcr) &
+ ASPEED_MBOX_BCR_RECV)) {
+ return -ERESTARTSYS;
+ }
+
+ mutex_lock(&mbox->mutex);
+
+ for (i = *ppos; count > 0 && i < model->dr_num; i++) {
+ uint8_t reg = aspeed_mbox_inb(mbox, ASPEED_MBOX_DR(model->dr, i));
+
+ ret = __put_user(reg, p);
+ if (ret)
+ goto out_unlock;
+
+ p++;
+ count--;
+ }
+
+ /* ASPEED_MBOX_BCR_RECV bit is write to clear, this also unmasks in 1 step */
+ aspeed_mbox_outb(mbox, ASPEED_MBOX_BCR_RECV, model->bcr);
+ ret = p - buf;
+
+out_unlock:
+ mutex_unlock(&mbox->mutex);
+ return ret;
+}
+
+static ssize_t aspeed_mbox_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct aspeed_mbox *mbox = file_mbox(file);
+ const struct aspeed_mbox_model *model = mbox->model;
+ const char __user *p = buf;
+ ssize_t ret;
+ char c;
+ int i;
+
+ if (!access_ok(buf, count))
+ return -EFAULT;
+
+ if (count + *ppos > model->dr_num)
+ return -EINVAL;
+
+ mutex_lock(&mbox->mutex);
+
+ for (i = *ppos; count > 0 && i < model->dr_num; i++) {
+ ret = __get_user(c, p);
+ if (ret)
+ goto out_unlock;
+
+ aspeed_mbox_outb(mbox, c, ASPEED_MBOX_DR(model->dr, i));
+ p++;
+ count--;
+ }
+
+ aspeed_mbox_outb(mbox, ASPEED_MBOX_BCR_SEND, model->bcr);
+ ret = p - buf;
+
+out_unlock:
+ mutex_unlock(&mbox->mutex);
+ return ret;
+}
+
+static __poll_t aspeed_mbox_poll(struct file *file, poll_table *wait)
+{
+ struct aspeed_mbox *mbox = file_mbox(file);
+ const struct aspeed_mbox_model *model = mbox->model;
+ __poll_t mask = 0;
+
+ poll_wait(file, &mbox->queue, wait);
+
+ if (aspeed_mbox_inb(mbox, model->bcr) & ASPEED_MBOX_BCR_RECV)
+ mask |= POLLIN;
+
+ return mask;
+}
+
+static int aspeed_mbox_release(struct inode *inode, struct file *file)
+{
+ atomic_dec(&aspeed_mbox_open_count);
+ return 0;
+}
+
+static long aspeed_mbox_ioctl(struct file *file, unsigned int cmd,
+ unsigned long param)
+{
+ long ret = 0;
+ struct aspeed_mbox *mbox = file_mbox(file);
+ const struct aspeed_mbox_model *model = mbox->model;
+ struct aspeed_mbox_ioctl_data data;
+
+ switch (cmd) {
+ case ASPEED_MBOX_IOCTL_GET_SIZE:
+ data.data = model->dr_num;
+ if (copy_to_user((void __user *)param, &data, sizeof(data)))
+ ret = -EFAULT;
+ break;
+ default:
+ ret = -ENOTTY;
+ break;
+ }
+
+ return ret;
+}
+
+static const struct file_operations aspeed_mbox_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_seek_end_llseek,
+ .read = aspeed_mbox_read,
+ .write = aspeed_mbox_write,
+ .open = aspeed_mbox_open,
+ .release = aspeed_mbox_release,
+ .poll = aspeed_mbox_poll,
+ .unlocked_ioctl = aspeed_mbox_ioctl,
+};
+
+static irqreturn_t aspeed_mbox_irq(int irq, void *arg)
+{
+ struct aspeed_mbox *mbox = arg;
+ const struct aspeed_mbox_model *model = mbox->model;
+
+ if (!(aspeed_mbox_inb(mbox, model->bcr) & ASPEED_MBOX_BCR_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 */
+ aspeed_mbox_outb(mbox, ASPEED_MBOX_BCR_MASK, model->bcr);
+
+ wake_up(&mbox->queue);
+ return IRQ_HANDLED;
+}
+
+static int aspeed_mbox_config_irq(struct aspeed_mbox *mbox,
+ struct platform_device *pdev)
+{
+ const struct aspeed_mbox_model *model = mbox->model;
+ struct device *dev = &pdev->dev;
+ int i, rc, irq;
+
+ irq = irq_of_parse_and_map(dev->of_node, 0);
+ if (!irq)
+ return -ENODEV;
+
+ rc = devm_request_irq(dev, irq, aspeed_mbox_irq,
+ IRQF_SHARED, DEVICE_NAME, mbox);
+ if (rc < 0) {
+ dev_err(dev, "Unable to request IRQ %d\n", irq);
+ return rc;
+ }
+
+ /*
+ * Disable all register based interrupts.
+ */
+ for (i = 0; i < model->dr_num / 8; ++i)
+ aspeed_mbox_outb(mbox, 0x00, ASPEED_MBOX_BIE(model->bie, i));
+
+ /* These registers are write one to clear. Clear them. */
+ for (i = 0; i < model->dr_num / 8; ++i)
+ aspeed_mbox_outb(mbox, 0xff, ASPEED_MBOX_STR(model->str, i));
+
+ aspeed_mbox_outb(mbox, ASPEED_MBOX_BCR_RECV, model->bcr);
+ return 0;
+}
+
+static int aspeed_mbox_probe(struct platform_device *pdev)
+{
+ struct aspeed_mbox *mbox;
+ struct device *dev;
+ int rc;
+
+ dev = &pdev->dev;
+
+ mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+ if (!mbox)
+ return -ENOMEM;
+
+ dev_set_drvdata(&pdev->dev, mbox);
+
+ rc = of_property_read_u32(dev->of_node, "reg", &mbox->base);
+ if (rc) {
+ dev_err(dev, "Couldn't read reg device tree property\n");
+ return rc;
+ }
+
+ mbox->model = of_device_get_match_data(dev);
+ if (IS_ERR(mbox->model)) {
+ dev_err(dev, "Couldn't get model data\n");
+ return -ENODEV;
+ }
+
+ mbox->map = syscon_node_to_regmap(
+ pdev->dev.parent->of_node);
+ if (IS_ERR(mbox->map)) {
+ dev_err(dev, "Couldn't get regmap\n");
+ return -ENODEV;
+ }
+
+ mutex_init(&mbox->mutex);
+ init_waitqueue_head(&mbox->queue);
+
+ mbox->miscdev.minor = MISC_DYNAMIC_MINOR;
+ mbox->miscdev.name = DEVICE_NAME;
+ mbox->miscdev.fops = &aspeed_mbox_fops;
+ mbox->miscdev.parent = dev;
+ rc = misc_register(&mbox->miscdev);
+ if (rc) {
+ dev_err(dev, "Unable to register device\n");
+ return rc;
+ }
+
+ rc = aspeed_mbox_config_irq(mbox, pdev);
+ if (rc) {
+ dev_err(dev, "Failed to configure IRQ\n");
+ misc_deregister(&mbox->miscdev);
+ return rc;
+ }
+
+ return 0;
+}
+
+static int aspeed_mbox_remove(struct platform_device *pdev)
+{
+ struct aspeed_mbox *mbox = dev_get_drvdata(&pdev->dev);
+
+ misc_deregister(&mbox->miscdev);
+
+ return 0;
+}
+
+static const struct aspeed_mbox_model ast2400_model = {
+ .dr_num = 16,
+ .dr = 0x0,
+ .str = 0x40,
+ .bcr = 0x48,
+ .hcr = 0x4c,
+ .bie = 0x50,
+ .hie = 0x58,
+};
+
+static const struct aspeed_mbox_model ast2500_model = {
+ .dr_num = 16,
+ .dr = 0x0,
+ .str = 0x40,
+ .bcr = 0x48,
+ .hcr = 0x4c,
+ .bie = 0x50,
+ .hie = 0x58,
+};
+
+static const struct aspeed_mbox_model ast2600_model = {
+ .dr_num = 32,
+ .dr = 0x0,
+ .str = 0x80,
+ .bcr = 0x90,
+ .hcr = 0x94,
+ .bie = 0xa0,
+ .hie = 0xb0,
+};
+
+static const struct of_device_id aspeed_mbox_match[] = {
+ { .compatible = "aspeed,ast2400-mbox",
+ .data = &ast2400_model },
+ { .compatible = "aspeed,ast2500-mbox",
+ .data = &ast2500_model },
+ { .compatible = "aspeed,ast2600-mbox",
+ .data = &ast2600_model },
+ { },
+};
+
+static struct platform_driver aspeed_mbox_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = aspeed_mbox_match,
+ },
+ .probe = aspeed_mbox_probe,
+ .remove = aspeed_mbox_remove,
+};
+
+module_platform_driver(aspeed_mbox_driver);
+MODULE_DEVICE_TABLE(of, aspeed_mbox_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cyril Bur <cyrilbur at gmail.com>");
+MODULE_AUTHOR("Chia-Wei Wang <chiawei_wang at aspeedtech.com");
+MODULE_DESCRIPTION("Aspeed mailbox device driver");
--
2.17.1
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