Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 493 insertions, 0 deletions

diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
new file mode 100644
index 0000000000..7450904e33
--- /dev/null
+++ b/drivers/char/ipmi/bt-bmc.c
@@ -0,0 +1,493 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2015-2016, IBM Corporation.
+ */
+
+#include <linux/atomic.h>
+#include <linux/bt-bmc.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+
+/*
+ * This is a BMC device used to communicate to the host
+ */
+#define DEVICE_NAME	"ipmi-bt-host"
+
+#define BT_IO_BASE	0xe4
+#define BT_IRQ		10
+
+#define BT_CR0		0x0
+#define   BT_CR0_IO_BASE		16
+#define   BT_CR0_IRQ			12
+#define   BT_CR0_EN_CLR_SLV_RDP		0x8
+#define   BT_CR0_EN_CLR_SLV_WRP		0x4
+#define   BT_CR0_ENABLE_IBT		0x1
+#define BT_CR1		0x4
+#define   BT_CR1_IRQ_H2B	0x01
+#define   BT_CR1_IRQ_HBUSY	0x40
+#define BT_CR2		0x8
+#define   BT_CR2_IRQ_H2B	0x01
+#define   BT_CR2_IRQ_HBUSY	0x40
+#define BT_CR3		0xc
+#define BT_CTRL		0x10
+#define   BT_CTRL_B_BUSY		0x80
+#define   BT_CTRL_H_BUSY		0x40
+#define   BT_CTRL_OEM0			0x20
+#define   BT_CTRL_SMS_ATN		0x10
+#define   BT_CTRL_B2H_ATN		0x08
+#define   BT_CTRL_H2B_ATN		0x04
+#define   BT_CTRL_CLR_RD_PTR		0x02
+#define   BT_CTRL_CLR_WR_PTR		0x01
+#define BT_BMC2HOST	0x14
+#define BT_INTMASK	0x18
+#define   BT_INTMASK_B2H_IRQEN		0x01
+#define   BT_INTMASK_B2H_IRQ		0x02
+#define   BT_INTMASK_BMC_HWRST		0x80
+
+#define BT_BMC_BUFFER_SIZE 256
+
+struct bt_bmc {
+	struct device		dev;
+	struct miscdevice	miscdev;
+	void __iomem		*base;
+	int			irq;
+	wait_queue_head_t	queue;
+	struct timer_list	poll_timer;
+	struct mutex		mutex;
+};
+
+static atomic_t open_count = ATOMIC_INIT(0);
+
+static u8 bt_inb(struct bt_bmc *bt_bmc, int reg)
+{
+	return readb(bt_bmc->base + reg);
+}
+
+static void bt_outb(struct bt_bmc *bt_bmc, u8 data, int reg)
+{
+	writeb(data, bt_bmc->base + reg);
+}
+
+static void clr_rd_ptr(struct bt_bmc *bt_bmc)
+{
+	bt_outb(bt_bmc, BT_CTRL_CLR_RD_PTR, BT_CTRL);
+}
+
+static void clr_wr_ptr(struct bt_bmc *bt_bmc)
+{
+	bt_outb(bt_bmc, BT_CTRL_CLR_WR_PTR, BT_CTRL);
+}
+
+static void clr_h2b_atn(struct bt_bmc *bt_bmc)
+{
+	bt_outb(bt_bmc, BT_CTRL_H2B_ATN, BT_CTRL);
+}
+
+static void set_b_busy(struct bt_bmc *bt_bmc)
+{
+	if (!(bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_B_BUSY))
+		bt_outb(bt_bmc, BT_CTRL_B_BUSY, BT_CTRL);
+}
+
+static void clr_b_busy(struct bt_bmc *bt_bmc)
+{
+	if (bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_B_BUSY)
+		bt_outb(bt_bmc, BT_CTRL_B_BUSY, BT_CTRL);
+}
+
+static void set_b2h_atn(struct bt_bmc *bt_bmc)
+{
+	bt_outb(bt_bmc, BT_CTRL_B2H_ATN, BT_CTRL);
+}
+
+static u8 bt_read(struct bt_bmc *bt_bmc)
+{
+	return bt_inb(bt_bmc, BT_BMC2HOST);
+}
+
+static ssize_t bt_readn(struct bt_bmc *bt_bmc, u8 *buf, size_t n)
+{
+	int i;
+
+	for (i = 0; i < n; i++)
+		buf[i] = bt_read(bt_bmc);
+	return n;
+}
+
+static void bt_write(struct bt_bmc *bt_bmc, u8 c)
+{
+	bt_outb(bt_bmc, c, BT_BMC2HOST);
+}
+
+static ssize_t bt_writen(struct bt_bmc *bt_bmc, u8 *buf, size_t n)
+{
+	int i;
+
+	for (i = 0; i < n; i++)
+		bt_write(bt_bmc, buf[i]);
+	return n;
+}
+
+static void set_sms_atn(struct bt_bmc *bt_bmc)
+{
+	bt_outb(bt_bmc, BT_CTRL_SMS_ATN, BT_CTRL);
+}
+
+static struct bt_bmc *file_bt_bmc(struct file *file)
+{
+	return container_of(file->private_data, struct bt_bmc, miscdev);
+}
+
+static int bt_bmc_open(struct inode *inode, struct file *file)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+
+	if (atomic_inc_return(&open_count) == 1) {
+		clr_b_busy(bt_bmc);
+		return 0;
+	}
+
+	atomic_dec(&open_count);
+	return -EBUSY;
+}
+
+/*
+ * The BT (Block Transfer) interface means that entire messages are
+ * buffered by the host before a notification is sent to the BMC that
+ * there is data to be read. The first byte is the length and the
+ * message data follows. The read operation just tries to capture the
+ * whole before returning it to userspace.
+ *
+ * BT Message format :
+ *
+ *    Byte 1  Byte 2     Byte 3  Byte 4  Byte 5:N
+ *    Length  NetFn/LUN  Seq     Cmd     Data
+ *
+ */
+static ssize_t bt_bmc_read(struct file *file, char __user *buf,
+			   size_t count, loff_t *ppos)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+	u8 len;
+	int len_byte = 1;
+	u8 kbuffer[BT_BMC_BUFFER_SIZE];
+	ssize_t ret = 0;
+	ssize_t nread;
+
+	WARN_ON(*ppos);
+
+	if (wait_event_interruptible(bt_bmc->queue,
+				     bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))
+		return -ERESTARTSYS;
+
+	mutex_lock(&bt_bmc->mutex);
+
+	if (unlikely(!(bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))) {
+		ret = -EIO;
+		goto out_unlock;
+	}
+
+	set_b_busy(bt_bmc);
+	clr_h2b_atn(bt_bmc);
+	clr_rd_ptr(bt_bmc);
+
+	/*
+	 * The BT frames start with the message length, which does not
+	 * include the length byte.
+	 */
+	kbuffer[0] = bt_read(bt_bmc);
+	len = kbuffer[0];
+
+	/* We pass the length back to userspace as well */
+	if (len + 1 > count)
+		len = count - 1;
+
+	while (len) {
+		nread = min_t(ssize_t, len, sizeof(kbuffer) - len_byte);
+
+		bt_readn(bt_bmc, kbuffer + len_byte, nread);
+
+		if (copy_to_user(buf, kbuffer, nread + len_byte)) {
+			ret = -EFAULT;
+			break;
+		}
+		len -= nread;
+		buf += nread + len_byte;
+		ret += nread + len_byte;
+		len_byte = 0;
+	}
+
+	clr_b_busy(bt_bmc);
+
+out_unlock:
+	mutex_unlock(&bt_bmc->mutex);
+	return ret;
+}
+
+/*
+ * BT Message response format :
+ *
+ *    Byte 1  Byte 2     Byte 3  Byte 4  Byte 5  Byte 6:N
+ *    Length  NetFn/LUN  Seq     Cmd     Code    Data
+ */
+static ssize_t bt_bmc_write(struct file *file, const char __user *buf,
+			    size_t count, loff_t *ppos)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+	u8 kbuffer[BT_BMC_BUFFER_SIZE];
+	ssize_t ret = 0;
+	ssize_t nwritten;
+
+	/*
+	 * send a minimum response size
+	 */
+	if (count < 5)
+		return -EINVAL;
+
+	WARN_ON(*ppos);
+
+	/*
+	 * There's no interrupt for clearing bmc busy so we have to
+	 * poll
+	 */
+	if (wait_event_interruptible(bt_bmc->queue,
+				     !(bt_inb(bt_bmc, BT_CTRL) &
+				       (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))))
+		return -ERESTARTSYS;
+
+	mutex_lock(&bt_bmc->mutex);
+
+	if (unlikely(bt_inb(bt_bmc, BT_CTRL) &
+		     (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))) {
+		ret = -EIO;
+		goto out_unlock;
+	}
+
+	clr_wr_ptr(bt_bmc);
+
+	while (count) {
+		nwritten = min_t(ssize_t, count, sizeof(kbuffer));
+		if (copy_from_user(&kbuffer, buf, nwritten)) {
+			ret = -EFAULT;
+			break;
+		}
+
+		bt_writen(bt_bmc, kbuffer, nwritten);
+
+		count -= nwritten;
+		buf += nwritten;
+		ret += nwritten;
+	}
+
+	set_b2h_atn(bt_bmc);
+
+out_unlock:
+	mutex_unlock(&bt_bmc->mutex);
+	return ret;
+}
+
+static long bt_bmc_ioctl(struct file *file, unsigned int cmd,
+			 unsigned long param)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+
+	switch (cmd) {
+	case BT_BMC_IOCTL_SMS_ATN:
+		set_sms_atn(bt_bmc);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+static int bt_bmc_release(struct inode *inode, struct file *file)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+
+	atomic_dec(&open_count);
+	set_b_busy(bt_bmc);
+	return 0;
+}
+
+static __poll_t bt_bmc_poll(struct file *file, poll_table *wait)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+	__poll_t mask = 0;
+	u8 ctrl;
+
+	poll_wait(file, &bt_bmc->queue, wait);
+
+	ctrl = bt_inb(bt_bmc, BT_CTRL);
+
+	if (ctrl & BT_CTRL_H2B_ATN)
+		mask |= EPOLLIN;
+
+	if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))
+		mask |= EPOLLOUT;
+
+	return mask;
+}
+
+static const struct file_operations bt_bmc_fops = {
+	.owner		= THIS_MODULE,
+	.open		= bt_bmc_open,
+	.read		= bt_bmc_read,
+	.write		= bt_bmc_write,
+	.release	= bt_bmc_release,
+	.poll		= bt_bmc_poll,
+	.unlocked_ioctl	= bt_bmc_ioctl,
+};
+
+static void poll_timer(struct timer_list *t)
+{
+	struct bt_bmc *bt_bmc = from_timer(bt_bmc, t, poll_timer);
+
+	bt_bmc->poll_timer.expires += msecs_to_jiffies(500);
+	wake_up(&bt_bmc->queue);
+	add_timer(&bt_bmc->poll_timer);
+}
+
+static irqreturn_t bt_bmc_irq(int irq, void *arg)
+{
+	struct bt_bmc *bt_bmc = arg;
+	u32 reg;
+
+	reg = readl(bt_bmc->base + BT_CR2);
+
+	reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
+	if (!reg)
+		return IRQ_NONE;
+
+	/* ack pending IRQs */
+	writel(reg, bt_bmc->base + BT_CR2);
+
+	wake_up(&bt_bmc->queue);
+	return IRQ_HANDLED;
+}
+
+static int bt_bmc_config_irq(struct bt_bmc *bt_bmc,
+			     struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int rc;
+	u32 reg;
+
+	bt_bmc->irq = platform_get_irq_optional(pdev, 0);
+	if (bt_bmc->irq < 0)
+		return bt_bmc->irq;
+
+	rc = devm_request_irq(dev, bt_bmc->irq, bt_bmc_irq, IRQF_SHARED,
+			      DEVICE_NAME, bt_bmc);
+	if (rc < 0) {
+		dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);
+		bt_bmc->irq = rc;
+		return rc;
+	}
+
+	/*
+	 * Configure IRQs on the bmc clearing the H2B and HBUSY bits;
+	 * H2B will be asserted when the bmc has data for us; HBUSY
+	 * will be cleared (along with B2H) when we can write the next
+	 * message to the BT buffer
+	 */
+	reg = readl(bt_bmc->base + BT_CR1);
+	reg |= BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY;
+	writel(reg, bt_bmc->base + BT_CR1);
+
+	return 0;
+}
+
+static int bt_bmc_probe(struct platform_device *pdev)
+{
+	struct bt_bmc *bt_bmc;
+	struct device *dev;
+	int rc;
+
+	dev = &pdev->dev;
+	dev_info(dev, "Found bt bmc device\n");
+
+	bt_bmc = devm_kzalloc(dev, sizeof(*bt_bmc), GFP_KERNEL);
+	if (!bt_bmc)
+		return -ENOMEM;
+
+	dev_set_drvdata(&pdev->dev, bt_bmc);
+
+	bt_bmc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(bt_bmc->base))
+		return PTR_ERR(bt_bmc->base);
+
+	mutex_init(&bt_bmc->mutex);
+	init_waitqueue_head(&bt_bmc->queue);
+
+	bt_bmc->miscdev.minor	= MISC_DYNAMIC_MINOR;
+	bt_bmc->miscdev.name	= DEVICE_NAME;
+	bt_bmc->miscdev.fops	= &bt_bmc_fops;
+	bt_bmc->miscdev.parent = dev;
+	rc = misc_register(&bt_bmc->miscdev);
+	if (rc) {
+		dev_err(dev, "Unable to register misc device\n");
+		return rc;
+	}
+
+	bt_bmc_config_irq(bt_bmc, pdev);
+
+	if (bt_bmc->irq >= 0) {
+		dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);
+	} else {
+		dev_info(dev, "No IRQ; using timer\n");
+		timer_setup(&bt_bmc->poll_timer, poll_timer, 0);
+		bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10);
+		add_timer(&bt_bmc->poll_timer);
+	}
+
+	writel((BT_IO_BASE << BT_CR0_IO_BASE) |
+		     (BT_IRQ << BT_CR0_IRQ) |
+		     BT_CR0_EN_CLR_SLV_RDP |
+		     BT_CR0_EN_CLR_SLV_WRP |
+		     BT_CR0_ENABLE_IBT,
+		bt_bmc->base + BT_CR0);
+
+	clr_b_busy(bt_bmc);
+
+	return 0;
+}
+
+static int bt_bmc_remove(struct platform_device *pdev)
+{
+	struct bt_bmc *bt_bmc = dev_get_drvdata(&pdev->dev);
+
+	misc_deregister(&bt_bmc->miscdev);
+	if (bt_bmc->irq < 0)
+		del_timer_sync(&bt_bmc->poll_timer);
+	return 0;
+}
+
+static const struct of_device_id bt_bmc_match[] = {
+	{ .compatible = "aspeed,ast2400-ibt-bmc" },
+	{ .compatible = "aspeed,ast2500-ibt-bmc" },
+	{ .compatible = "aspeed,ast2600-ibt-bmc" },
+	{ },
+};
+
+static struct platform_driver bt_bmc_driver = {
+	.driver = {
+		.name		= DEVICE_NAME,
+		.of_match_table = bt_bmc_match,
+	},
+	.probe = bt_bmc_probe,
+	.remove = bt_bmc_remove,
+};
+
+module_platform_driver(bt_bmc_driver);
+
+MODULE_DEVICE_TABLE(of, bt_bmc_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alistair Popple <alistair@popple.id.au>");
+MODULE_DESCRIPTION("Linux device interface to the IPMI BT interface");