[RFC PATCH linux dev-4.7 0/6] iBT interface changes

[RFC PATCH linux dev-4.7 0/6] iBT interface changes

[Cédric Le Goater]

Hello,

This patchset introduces a couple of changes on the driver for the iBT
interface on Aspeed SOCs. These were suggested by mainline and have
some conficts with the OpenBMC userspace. The most important are name
changes, which impact the btbridge daemon, but nothing is requiring a
redesign of the stack.

The previous driver is reverted and and reincluded in its mainline
form. So you should mostly check patch 4 and quickly 5,6. The merge
in openbmc kernel can wait mainline's green light I think. 

You can find the btbridge changes:

     https://github.com/legoater/btbridge

Thanks,

C.


Alistair Popple (1):
  misc: Add Aspeed BT IPMI BMC driver

Cédric Le Goater (5):
  Revert "misc: Add Aspeed BT IPMI host driver"
  ARM: aspeed: remove previous definitions in default config
  ARM: dts: aspeed: remove previous iBT definitions
  ARM: aspeed: Add defconfigs for CONFIG_ASPEED_BT_IPMI_BMC
  ARM: dts: aspeed: Enable BT IPMI BMC device

 .../bindings/char/ipmi/aspeed,bt-bmc.txt           |  19 +
 arch/arm/boot/dts/aspeed-g4.dtsi                   |   2 +-
 arch/arm/boot/dts/aspeed-g5.dtsi                   |   2 +-
 arch/arm/configs/aspeed_g4_defconfig               |   3 +-
 arch/arm/configs/aspeed_g5_defconfig               |   3 +-
 drivers/char/ipmi/Kconfig                          |   7 +
 drivers/char/ipmi/Makefile                         |   1 +
 drivers/char/ipmi/bt-bmc.c                         | 475 +++++++++++++++++++++
 drivers/misc/Kconfig                               |   5 -
 drivers/misc/Makefile                              |   1 -
 drivers/misc/bt-host.c                             | 427 ------------------
 include/uapi/linux/Kbuild                          |   2 +-
 include/uapi/linux/{bt-host.h => bt-bmc.h}         |  12 +-
 13 files changed, 515 insertions(+), 444 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
 create mode 100644 drivers/char/ipmi/bt-bmc.c
 delete mode 100644 drivers/misc/bt-host.c
 rename include/uapi/linux/{bt-host.h => bt-bmc.h} (55%)

-- 
2.7.4

[RFC PATCH linux dev-4.7 1/6] Revert "misc: Add Aspeed BT IPMI host driver"

[Cédric Le Goater]

This reverts commit f7b4775fdf656f00f1b692bf3db97b3a8088c057.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 drivers/misc/Kconfig         |   5 -
 drivers/misc/Makefile        |   1 -
 drivers/misc/bt-host.c       | 427 -------------------------------------------
 include/uapi/linux/Kbuild    |   1 -
 include/uapi/linux/bt-host.h |  18 --
 5 files changed, 452 deletions(-)
 delete mode 100644 drivers/misc/bt-host.c
 delete mode 100644 include/uapi/linux/bt-host.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4617ddc3c538..a216b4667742 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -804,11 +804,6 @@ 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 ASPEED_BT_IPMI_HOST
-	tristate "BT IPMI host driver"
-	help
-	  Support for the Aspeed BT ipmi host.
-
 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 724861b7f291..b2fb6dbffcef 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -57,4 +57,3 @@ obj-$(CONFIG_ECHO)		+= echo/
 obj-$(CONFIG_VEXPRESS_SYSCFG)	+= vexpress-syscfg.o
 obj-$(CONFIG_CXL_BASE)		+= cxl/
 obj-$(CONFIG_PANEL)             += panel.o
-obj-$(CONFIG_ASPEED_BT_IPMI_HOST)	+= bt-host.o
diff --git a/drivers/misc/bt-host.c b/drivers/misc/bt-host.c
deleted file mode 100644
index a5e765d683fc..000000000000
--- a/drivers/misc/bt-host.c
+++ /dev/null
@@ -1,427 +0,0 @@
-/*
- * 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/bt-host.h>
-
-#define DEVICE_NAME	"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
-
-struct bt_host {
-	struct device		dev;
-	struct miscdevice	miscdev;
-	void __iomem		*base;
-	int			open_count;
-	int			irq;
-	wait_queue_head_t	queue;
-	struct timer_list	poll_timer;
-};
-
-static u8 bt_inb(struct bt_host *bt_host, int reg)
-{
-	return ioread8(bt_host->base + reg);
-}
-
-static void bt_outb(struct bt_host *bt_host, u8 data, int reg)
-{
-	iowrite8(data, bt_host->base + reg);
-}
-
-static void clr_rd_ptr(struct bt_host *bt_host)
-{
-	bt_outb(bt_host, BT_CTRL_CLR_RD_PTR, BT_CTRL);
-}
-
-static void clr_wr_ptr(struct bt_host *bt_host)
-{
-	bt_outb(bt_host, BT_CTRL_CLR_WR_PTR, BT_CTRL);
-}
-
-static void clr_h2b_atn(struct bt_host *bt_host)
-{
-	bt_outb(bt_host, BT_CTRL_H2B_ATN, BT_CTRL);
-}
-
-static void set_b_busy(struct bt_host *bt_host)
-{
-	if (!(bt_inb(bt_host, BT_CTRL) & BT_CTRL_B_BUSY))
-		bt_outb(bt_host, BT_CTRL_B_BUSY, BT_CTRL);
-}
-
-static void clr_b_busy(struct bt_host *bt_host)
-{
-	if (bt_inb(bt_host, BT_CTRL) & BT_CTRL_B_BUSY)
-		bt_outb(bt_host, BT_CTRL_B_BUSY, BT_CTRL);
-}
-
-static void set_b2h_atn(struct bt_host *bt_host)
-{
-	bt_outb(bt_host, BT_CTRL_B2H_ATN, BT_CTRL);
-}
-
-static u8 bt_read(struct bt_host *bt_host)
-{
-	return bt_inb(bt_host, BT_BMC2HOST);
-}
-
-static void bt_write(struct bt_host *bt_host, u8 c)
-{
-	bt_outb(bt_host, c, BT_BMC2HOST);
-}
-
-static void set_sms_atn(struct bt_host *bt_host)
-{
-	bt_outb(bt_host, BT_CTRL_SMS_ATN, BT_CTRL);
-}
-
-static struct bt_host *file_bt_host(struct file *file)
-{
-	return container_of(file->private_data, struct bt_host, miscdev);
-}
-
-static int bt_host_open(struct inode *inode, struct file *file)
-{
-	struct bt_host *bt_host = file_bt_host(file);
-
-	clr_b_busy(bt_host);
-
-	return 0;
-}
-
-static ssize_t bt_host_read(struct file *file, char __user *buf,
-				size_t count, loff_t *ppos)
-{
-	struct bt_host *bt_host = file_bt_host(file);
-	char __user *p = buf;
-	u8 len;
-
-	if (!access_ok(VERIFY_WRITE, buf, count))
-		return -EFAULT;
-
-	WARN_ON(*ppos);
-
-	if (wait_event_interruptible(bt_host->queue,
-				bt_inb(bt_host, BT_CTRL) & BT_CTRL_H2B_ATN))
-		return -ERESTARTSYS;
-
-	set_b_busy(bt_host);
-	clr_h2b_atn(bt_host);
-	clr_rd_ptr(bt_host);
-
-	len = bt_read(bt_host);
-	__put_user(len, p++);
-
-	/* We pass the length back as well */
-	if (len + 1 > count)
-		len = count - 1;
-
-	while(len) {
-		if (__put_user(bt_read(bt_host), p))
-			return -EFAULT;
-		len--; p++;
-	}
-
-	clr_b_busy(bt_host);
-
-	return p - buf;
-}
-
-static ssize_t bt_host_write(struct file *file, const char __user *buf,
-				size_t count, loff_t *ppos)
-{
-	struct bt_host *bt_host = file_bt_host(file);
-	const char __user *p = buf;
-	u8 c;
-
-	if (!access_ok(VERIFY_READ, buf, count))
-		return -EFAULT;
-
-	WARN_ON(*ppos);
-
-	/* There's no interrupt for clearing host busy so we have to
-	 * poll */
-	if (wait_event_interruptible(bt_host->queue,
-				!(bt_inb(bt_host, BT_CTRL) &
-					(BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN))))
-		return -ERESTARTSYS;
-
-	clr_wr_ptr(bt_host);
-
-	while (count) {
-		if (__get_user(c, p))
-			return -EFAULT;
-
-		bt_write(bt_host, c);
-		count--; p++;
-	}
-
-	set_b2h_atn(bt_host);
-
-	return p - buf;
-}
-
-static long bt_host_ioctl(struct file *file, unsigned int cmd,
-		unsigned long param)
-{
-	struct bt_host *bt_host = file_bt_host(file);
-	switch (cmd) {
-	case BT_HOST_IOCTL_SMS_ATN:
-		set_sms_atn(bt_host);
-		return 0;
-	}
-	return -EINVAL;
-}
-
-static int bt_host_release(struct inode *inode, struct file *file)
-{
-	struct bt_host *bt_host = file_bt_host(file);
-	set_b_busy(bt_host);
-	return 0;
-}
-
-static unsigned int bt_host_poll(struct file *file, poll_table *wait)
-{
-	struct bt_host *bt_host = file_bt_host(file);
-	unsigned int mask = 0;
-	uint8_t ctrl;
-
-	poll_wait(file, &bt_host->queue, wait);
-
-	ctrl = bt_inb(bt_host, BT_CTRL);
-
-	if (ctrl & BT_CTRL_H2B_ATN)
-		mask |= POLLIN;
-
-	if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))
-		mask |= POLLOUT;
-
-	return mask;
-}
-
-static const struct file_operations bt_host_fops = {
-	.owner		= THIS_MODULE,
-	.open		= bt_host_open,
-	.read		= bt_host_read,
-	.write		= bt_host_write,
-	.release	= bt_host_release,
-	.poll		= bt_host_poll,
-	.unlocked_ioctl	= bt_host_ioctl,
-};
-
-static void poll_timer(unsigned long data)
-{
-	struct bt_host *bt_host = (void *)data;
-	bt_host->poll_timer.expires += msecs_to_jiffies(500);
-	wake_up(&bt_host->queue);
-	add_timer(&bt_host->poll_timer);
-}
-
-static irqreturn_t bt_host_irq(int irq, void *arg)
-{
-	struct bt_host *bt_host = arg;
-	uint32_t reg;
-
-	reg = ioread32(bt_host->base + BT_CR2);
-	reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
-	if (!reg)
-		return IRQ_NONE;
-
-	/* ack pending IRQs */
-	iowrite32(reg, bt_host->base + BT_CR2);
-
-	wake_up(&bt_host->queue);
-	return IRQ_HANDLED;
-}
-
-static int bt_host_config_irq(struct bt_host *bt_host,
-		struct platform_device *pdev)
-{
-	struct device *dev = &pdev->dev;
-	uint32_t reg;
-	int rc;
-
-	bt_host->irq = irq_of_parse_and_map(dev->of_node, 0);
-	if (!bt_host->irq)
-		return -ENODEV;
-
-	rc = devm_request_irq(dev, bt_host->irq, bt_host_irq, IRQF_SHARED,
-			DEVICE_NAME, bt_host);
-	if (rc < 0) {
-		dev_warn(dev, "Unable to request IRQ %d\n", bt_host->irq);
-		bt_host->irq = 0;
-		return rc;
-	}
-
-	/* Configure IRQs on the host clearing the H2B and HBUSY bits;
-	 * H2B will be asserted when the host has data for us; HBUSY
-	 * will be cleared (along with B2H) when we can write the next
-	 * message to the BT buffer */
-	reg = ioread32(bt_host->base + BT_CR1);
-	reg |= BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY;
-	iowrite32(reg, bt_host->base + BT_CR1);
-
-	return 0;
-}
-
-static int bt_host_probe(struct platform_device *pdev)
-{
-	struct bt_host *bt_host;
-	struct device *dev;
-	struct resource *res;
-	int rc;
-
-	if (!pdev || !pdev->dev.of_node)
-		return -ENODEV;
-
-	dev = &pdev->dev;
-	dev_info(dev, "Found bt host device\n");
-
-	bt_host = devm_kzalloc(dev, sizeof(*bt_host), GFP_KERNEL);
-	if (!bt_host)
-		return -ENOMEM;
-
-	dev_set_drvdata(&pdev->dev, bt_host);
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(dev, "Unable to find resources\n");
-		rc = -ENXIO;
-		goto out_free;
-	}
-
-	bt_host->base = devm_ioremap_resource(&pdev->dev, res);
-	if (!bt_host->base) {
-		rc = -ENOMEM;
-		goto out_free;
-	}
-
-	init_waitqueue_head(&bt_host->queue);
-
-	bt_host->miscdev.minor	= MISC_DYNAMIC_MINOR,
-	bt_host->miscdev.name	= DEVICE_NAME,
-	bt_host->miscdev.fops	= &bt_host_fops,
-	bt_host->miscdev.parent = dev;
-	rc = misc_register(&bt_host->miscdev);
-	if (rc) {
-		dev_err(dev, "Unable to register device\n");
-		goto out_unmap;
-	}
-
-	bt_host_config_irq(bt_host, pdev);
-
-	if (bt_host->irq) {
-		dev_info(dev, "Using IRQ %d\n", bt_host->irq);
-	} else {
-		dev_info(dev, "No IRQ; using timer\n");
-		setup_timer(&bt_host->poll_timer, poll_timer,
-				(unsigned long)bt_host);
-		bt_host->poll_timer.expires = jiffies + msecs_to_jiffies(10);
-		add_timer(&bt_host->poll_timer);
-	}
-
-	iowrite32((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_host->base + BT_CR0);
-
-	clr_b_busy(bt_host);
-
-	return 0;
-
-out_unmap:
-	devm_iounmap(&pdev->dev, bt_host->base);
-
-out_free:
-	devm_kfree(dev, bt_host);
-	return rc;
-
-}
-
-static int bt_host_remove(struct platform_device *pdev)
-{
-	struct bt_host *bt_host = dev_get_drvdata(&pdev->dev);
-	misc_deregister(&bt_host->miscdev);
-	if (!bt_host->irq)
-		del_timer_sync(&bt_host->poll_timer);
-	devm_iounmap(&pdev->dev, bt_host->base);
-	devm_kfree(&pdev->dev, bt_host);
-	bt_host = NULL;
-
-	return 0;
-}
-
-static const struct of_device_id bt_host_match[] = {
-	{ .compatible = "aspeed,bt-host" },
-	{ },
-};
-
-static struct platform_driver bt_host_driver = {
-	.driver = {
-		.name		= DEVICE_NAME,
-		.of_match_table = bt_host_match,
-	},
-	.probe = bt_host_probe,
-	.remove = bt_host_remove,
-};
-
-module_platform_driver(bt_host_driver);
-
-MODULE_DEVICE_TABLE(of, bt_host_match);
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Alistair Popple <alistair@popple.id.au>");
-MODULE_DESCRIPTION("Linux device interface to the BT interface");
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index b55c81eff9d7..ec10cfef166a 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -74,7 +74,6 @@ header-y += bpf_common.h
 header-y += bpf.h
 header-y += bpqether.h
 header-y += bsg.h
-header-y += bt-host.h
 header-y += btrfs.h
 header-y += can.h
 header-y += capability.h
diff --git a/include/uapi/linux/bt-host.h b/include/uapi/linux/bt-host.h
deleted file mode 100644
index a4298d9e7e26..000000000000
--- a/include/uapi/linux/bt-host.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright 2015 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_BT_HOST_H
-#define _UAPI_LINUX_BT_HOST_H
-
-#include <linux/ioctl.h>
-
-#define __BT_HOST_IOCTL_MAGIC	0xb1
-#define BT_HOST_IOCTL_SMS_ATN	_IO(__BT_HOST_IOCTL_MAGIC, 0x00)
-
-#endif /* _UAPI_LINUX_BT_HOST_H */
-- 
2.7.4

[RFC PATCH linux dev-4.7 2/6] ARM: aspeed: remove previous definitions in default config

[Cédric Le Goater]

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/arm/configs/aspeed_g4_defconfig | 1 -
 arch/arm/configs/aspeed_g5_defconfig | 1 -
 2 files changed, 2 deletions(-)

diff --git a/arch/arm/configs/aspeed_g4_defconfig b/arch/arm/configs/aspeed_g4_defconfig
index 5cc4d4121462..fab53889b2cc 100644
--- a/arch/arm/configs/aspeed_g4_defconfig
+++ b/arch/arm/configs/aspeed_g4_defconfig
@@ -60,7 +60,6 @@ CONFIG_MTD_BLOCK=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_ASPEED_FLASH_SPI=y
 CONFIG_BLK_DEV_RAM=y
-CONFIG_ASPEED_BT_IPMI_HOST=y
 CONFIG_EEPROM_AT24=y
 CONFIG_NETDEVICES=y
 # CONFIG_NET_VENDOR_ARC is not set
diff --git a/arch/arm/configs/aspeed_g5_defconfig b/arch/arm/configs/aspeed_g5_defconfig
index d19cf3b498cf..3ccc91db96e3 100644
--- a/arch/arm/configs/aspeed_g5_defconfig
+++ b/arch/arm/configs/aspeed_g5_defconfig
@@ -62,7 +62,6 @@ CONFIG_MTD_BLOCK=y
 CONFIG_MTD_SPI_NOR=y
 CONFIG_ASPEED_FLASH_SPI=y
 CONFIG_BLK_DEV_RAM=y
-CONFIG_ASPEED_BT_IPMI_HOST=y
 CONFIG_EEPROM_AT24=y
 CONFIG_NETDEVICES=y
 # CONFIG_NET_VENDOR_ARC is not set
-- 
2.7.4

[RFC PATCH linux dev-4.7 3/6] ARM: dts: aspeed: remove previous iBT definitions

[Cédric Le Goater]

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/arm/boot/dts/aspeed-g4.dtsi | 6 ------
 arch/arm/boot/dts/aspeed-g5.dtsi | 6 ------
 2 files changed, 12 deletions(-)

diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi
index 072a9211ccaa..eb0122fa34c2 100644
--- a/arch/arm/boot/dts/aspeed-g4.dtsi
+++ b/arch/arm/boot/dts/aspeed-g4.dtsi
@@ -391,12 +391,6 @@
 				clocks = <&clk_apb>;
 			};
 
-			ibt: ibt@1e789140 {
-				compatible = "aspeed,bt-host";
-				reg = <0x1e789140 0x18>;
-				interrupts = <8>;
-			};
-
 			wdt1: wdt@1e785000 {
 				compatible = "aspeed,ast2400-wdt";
 				reg = <0x1e785000 0x1c>;
diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi
index f73a2b18e152..79abac876abf 100644
--- a/arch/arm/boot/dts/aspeed-g5.dtsi
+++ b/arch/arm/boot/dts/aspeed-g5.dtsi
@@ -255,12 +255,6 @@
 				clocks = <&clk_apb>;
 			};
 
-			ibt: ibt@1e789140 {
-				compatible = "aspeed,bt-host";
-				reg = <0x1e789140 0x18>;
-				interrupts = <8>;
-			};
-
 			wdt1: wdt@1e785000 {
 				compatible = "aspeed,ast2500-wdt";
 				reg = <0x1e785000 0x1c>;
-- 
2.7.4

[RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Cédric Le Goater]

From: Alistair Popple <alistair@popple.id.au>

This patch adds a simple device driver to expose the iBT interface on
Aspeed SOCs (AST2400 and AST2500) as a character device :
/dev/ipmi-bt-bmc.

The BT (Block Transfer) interface is used to perform in-band IPMI
communication from a BMC to the host. Entire messages are buffered
before sending a notification to the host, or the BMC when on the
other side, that there is data to be read. The driver implements the
BMC side of the BT interface.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
[clg: - did some checkpatch fixes
      - added a devicetree binding documentation
      - renamed 'bt_host' to 'bt_bmc' to reflect that the driver is
        the BMC side of the IPMI BT interface
      - remaned the device name to 'ipmi-bt-bmc'
      - introduced a temporary buffer to copy_{to,from}_user
      - used platform_get_irq()
      - move the driver under drivers/char/ipmi/ ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 .../bindings/char/ipmi/aspeed,bt-bmc.txt           |  19 +
 drivers/char/ipmi/Kconfig                          |   7 +
 drivers/char/ipmi/Makefile                         |   1 +
 drivers/char/ipmi/bt-bmc.c                         | 475 +++++++++++++++++++++
 include/uapi/linux/Kbuild                          |   1 +
 include/uapi/linux/bt-bmc.h                        |  18 +
 6 files changed, 521 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
 create mode 100644 drivers/char/ipmi/bt-bmc.c
 create mode 100644 include/uapi/linux/bt-bmc.h

diff --git a/Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt b/Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
new file mode 100644
index 000000000000..551323606f6e
--- /dev/null
+++ b/Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
@@ -0,0 +1,19 @@
+* Aspeed BT IPMI interface
+
+Required properties:
+
+- compatible : should be "aspeed,bt-bmc"
+- reg: physical address and size of the registers
+
+Optional properties:
+
+- interrupts: interrupt generated by the BT interface. without an
+  interrupt, the driver will operate in poll mode.
+
+Example:
+
+	ibt@1e789140 {
+		compatible = "aspeed,bt-bmc";
+		reg = <0x1e789140 0x18>;
+		interrupts = <8>;
+	};
diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 6ed9e9fe5233..f0cf4889ba66 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -88,3 +88,10 @@ config IPMI_POWEROFF
 	 the IPMI management controller is capable of this.
 
 endif # IPMI_HANDLER
+
+config ASPEED_BT_IPMI_BMC
+	tristate "BT IPMI bmc driver"
+	help
+	  Provides a driver for the BT IPMI interface found on Aspeed
+	  SOCs (AST2400 and AST2500). The driver implements the BMC
+	  side of the BT interface.
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index f3ffde1f5f1f..0d98cd91def1 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
 obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
 obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
 obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
+obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
new file mode 100644
index 000000000000..5069ed6f0646
--- /dev/null
+++ b/drivers/char/ipmi/bt-bmc.c
@@ -0,0 +1,475 @@
+/*
+ * Copyright (c) 2015-2016, 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/bt-bmc.h>
+
+#define DEVICE_NAME	"ipmi-bt-bmc"
+
+#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
+
+struct bt_bmc {
+	struct device		dev;
+	struct miscdevice	miscdev;
+	void __iomem		*base;
+	int			open_count;
+	int			irq;
+	wait_queue_head_t	queue;
+	struct timer_list	poll_timer;
+};
+
+static u8 bt_inb(struct bt_bmc *bt_bmc, int reg)
+{
+	return ioread8(bt_bmc->base + reg);
+}
+
+static void bt_outb(struct bt_bmc *bt_bmc, u8 data, int reg)
+{
+	iowrite8(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);
+
+	clr_b_busy(bt_bmc);
+
+	return 0;
+}
+
+#define BT_BMC_BUFFER_SIZE 256
+
+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;
+
+	if (!access_ok(VERIFY_WRITE, buf, count))
+		return -EFAULT;
+
+	WARN_ON(*ppos);
+
+	if (wait_event_interruptible(bt_bmc->queue,
+				bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))
+		return -ERESTARTSYS;
+
+	set_b_busy(bt_bmc);
+	clr_h2b_atn(bt_bmc);
+	clr_rd_ptr(bt_bmc);
+
+	/* The BT frames start with the message length, not including
+	 * the length byte
+	 */
+	kbuffer[0] = bt_read(bt_bmc);
+	len = kbuffer[0];
+
+	/* We pass the length back 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);
+
+	return ret;
+}
+
+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;
+
+	if (!access_ok(VERIFY_READ, buf, count))
+		return -EFAULT;
+
+	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;
+
+	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);
+
+	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);
+
+	set_b_busy(bt_bmc);
+	return 0;
+}
+
+static unsigned int bt_bmc_poll(struct file *file, poll_table *wait)
+{
+	struct bt_bmc *bt_bmc = file_bt_bmc(file);
+	unsigned int mask = 0;
+	uint8_t ctrl;
+
+	poll_wait(file, &bt_bmc->queue, wait);
+
+	ctrl = bt_inb(bt_bmc, BT_CTRL);
+
+	if (ctrl & BT_CTRL_H2B_ATN)
+		mask |= POLLIN;
+
+	if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))
+		mask |= POLLOUT;
+
+	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(unsigned long data)
+{
+	struct bt_bmc *bt_bmc = (void *)data;
+
+	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;
+	uint32_t reg;
+
+	reg = ioread32(bt_bmc->base + BT_CR2);
+	reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
+	if (!reg)
+		return IRQ_NONE;
+
+	/* ack pending IRQs */
+	iowrite32(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;
+	uint32_t reg;
+	int rc;
+
+	bt_bmc->irq = platform_get_irq(pdev, 0);
+	if (!bt_bmc->irq)
+		return -ENODEV;
+
+	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 = 0;
+		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 = ioread32(bt_bmc->base + BT_CR1);
+	reg |= BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY;
+	iowrite32(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;
+	struct resource *res;
+	int rc;
+
+	if (!pdev || !pdev->dev.of_node)
+		return -ENODEV;
+
+	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);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Unable to find resources\n");
+		rc = -ENXIO;
+		goto out_free;
+	}
+
+	bt_bmc->base = devm_ioremap_resource(&pdev->dev, res);
+	if (!bt_bmc->base) {
+		rc = -ENOMEM;
+		goto out_free;
+	}
+
+	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 device\n");
+		goto out_unmap;
+	}
+
+	bt_bmc_config_irq(bt_bmc, pdev);
+
+	if (bt_bmc->irq) {
+		dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);
+	} else {
+		dev_info(dev, "No IRQ; using timer\n");
+		setup_timer(&bt_bmc->poll_timer, poll_timer,
+				(unsigned long)bt_bmc);
+		bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10);
+		add_timer(&bt_bmc->poll_timer);
+	}
+
+	iowrite32((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;
+
+out_unmap:
+	devm_iounmap(&pdev->dev, bt_bmc->base);
+
+out_free:
+	devm_kfree(dev, bt_bmc);
+	return rc;
+
+}
+
+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)
+		del_timer_sync(&bt_bmc->poll_timer);
+	devm_iounmap(&pdev->dev, bt_bmc->base);
+	devm_kfree(&pdev->dev, bt_bmc);
+	bt_bmc = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id bt_bmc_match[] = {
+	{ .compatible = "aspeed,bt-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 BT interface");
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index ec10cfef166a..9493842de93b 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -74,6 +74,7 @@ header-y += bpf_common.h
 header-y += bpf.h
 header-y += bpqether.h
 header-y += bsg.h
+header-y += bt-bmc.h
 header-y += btrfs.h
 header-y += can.h
 header-y += capability.h
diff --git a/include/uapi/linux/bt-bmc.h b/include/uapi/linux/bt-bmc.h
new file mode 100644
index 000000000000..d9ec766a63d0
--- /dev/null
+++ b/include/uapi/linux/bt-bmc.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2015-2016, 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.
+ */
+
+#ifndef _UAPI_LINUX_BT_BMC_H
+#define _UAPI_LINUX_BT_BMC_H
+
+#include <linux/ioctl.h>
+
+#define __BT_BMC_IOCTL_MAGIC	0xb1
+#define BT_BMC_IOCTL_SMS_ATN	_IO(__BT_BMC_IOCTL_MAGIC, 0x00)
+
+#endif /* _UAPI_LINUX_BT_BMC_H */
-- 
2.7.4

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Joel Stanley]

On Thu, Sep 15, 2016 at 4:02 PM, Cédric Le Goater <clg@kaod.org> wrote:
> From: Alistair Popple <alistair@popple.id.au>
>
> This patch adds a simple device driver to expose the iBT interface on
> Aspeed SOCs (AST2400 and AST2500) as a character device :
> /dev/ipmi-bt-bmc.
>
> The BT (Block Transfer) interface is used to perform in-band IPMI
> communication from a BMC to the host. Entire messages are buffered
> before sending a notification to the host, or the BMC when on the
> other side, that there is data to be read. The driver implements the
> BMC side of the BT interface.
>
> Signed-off-by: Alistair Popple <alistair@popple.id.au>
> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> [clg: - did some checkpatch fixes
>       - added a devicetree binding documentation
>       - renamed 'bt_host' to 'bt_bmc' to reflect that the driver is
>         the BMC side of the IPMI BT interface
>       - remaned the device name to 'ipmi-bt-bmc'

I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
device?

>       - introduced a temporary buffer to copy_{to,from}_user
>       - used platform_get_irq()
>       - move the driver under drivers/char/ipmi/ ]
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>  .../bindings/char/ipmi/aspeed,bt-bmc.txt           |  19 +
>  drivers/char/ipmi/Kconfig                          |   7 +
>  drivers/char/ipmi/Makefile                         |   1 +
>  drivers/char/ipmi/bt-bmc.c                         | 475 +++++++++++++++++++++
>  include/uapi/linux/Kbuild                          |   1 +
>  include/uapi/linux/bt-bmc.h                        |  18 +
>  6 files changed, 521 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
>  create mode 100644 drivers/char/ipmi/bt-bmc.c
>  create mode 100644 include/uapi/linux/bt-bmc.h
>
> diff --git a/Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt b/Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
> new file mode 100644
> index 000000000000..551323606f6e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
> @@ -0,0 +1,19 @@
> +* Aspeed BT IPMI interface
> +
> +Required properties:
> +
> +- compatible : should be "aspeed,bt-bmc"
> +- reg: physical address and size of the registers
> +
> +Optional properties:
> +
> +- interrupts: interrupt generated by the BT interface. without an
> +  interrupt, the driver will operate in poll mode.
> +
> +Example:
> +
> +       ibt@1e789140 {
> +               compatible = "aspeed,bt-bmc";
> +               reg = <0x1e789140 0x18>;
> +               interrupts = <8>;
> +       };
> diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
> index 6ed9e9fe5233..f0cf4889ba66 100644
> --- a/drivers/char/ipmi/Kconfig
> +++ b/drivers/char/ipmi/Kconfig
> @@ -88,3 +88,10 @@ config IPMI_POWEROFF
>          the IPMI management controller is capable of this.
>
>  endif # IPMI_HANDLER
> +
> +config ASPEED_BT_IPMI_BMC
> +       tristate "BT IPMI bmc driver"
> +       help
> +         Provides a driver for the BT IPMI interface found on Aspeed
> +         SOCs (AST2400 and AST2500). The driver implements the BMC
> +         side of the BT interface.
> diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
> index f3ffde1f5f1f..0d98cd91def1 100644
> --- a/drivers/char/ipmi/Makefile
> +++ b/drivers/char/ipmi/Makefile
> @@ -11,3 +11,4 @@ obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
>  obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
>  obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
>  obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
> +obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
> diff --git a/drivers/char/ipmi/bt-bmc.c b/drivers/char/ipmi/bt-bmc.c
> new file mode 100644
> index 000000000000..5069ed6f0646
> --- /dev/null
> +++ b/drivers/char/ipmi/bt-bmc.c
> @@ -0,0 +1,475 @@
> +/*
> + * Copyright (c) 2015-2016, 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/bt-bmc.h>
> +
> +#define DEVICE_NAME    "ipmi-bt-bmc"
> +
> +#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
> +
> +struct bt_bmc {
> +       struct device           dev;
> +       struct miscdevice       miscdev;
> +       void __iomem            *base;
> +       int                     open_count;
> +       int                     irq;
> +       wait_queue_head_t       queue;
> +       struct timer_list       poll_timer;
> +};
> +
> +static u8 bt_inb(struct bt_bmc *bt_bmc, int reg)
> +{
> +       return ioread8(bt_bmc->base + reg);
> +}
> +
> +static void bt_outb(struct bt_bmc *bt_bmc, u8 data, int reg)
> +{
> +       iowrite8(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);
> +
> +       clr_b_busy(bt_bmc);
> +
> +       return 0;
> +}
> +
> +#define BT_BMC_BUFFER_SIZE 256
> +
> +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;
> +
> +       if (!access_ok(VERIFY_WRITE, buf, count))
> +               return -EFAULT;
> +
> +       WARN_ON(*ppos);
> +
> +       if (wait_event_interruptible(bt_bmc->queue,
> +                               bt_inb(bt_bmc, BT_CTRL) & BT_CTRL_H2B_ATN))
> +               return -ERESTARTSYS;
> +
> +       set_b_busy(bt_bmc);
> +       clr_h2b_atn(bt_bmc);
> +       clr_rd_ptr(bt_bmc);
> +
> +       /* The BT frames start with the message length, not including
> +        * the length byte
> +        */
> +       kbuffer[0] = bt_read(bt_bmc);
> +       len = kbuffer[0];
> +
> +       /* We pass the length back 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);
> +
> +       return ret;
> +}
> +
> +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;
> +
> +       if (!access_ok(VERIFY_READ, buf, count))
> +               return -EFAULT;
> +
> +       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;
> +
> +       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);
> +
> +       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);
> +
> +       set_b_busy(bt_bmc);
> +       return 0;
> +}
> +
> +static unsigned int bt_bmc_poll(struct file *file, poll_table *wait)
> +{
> +       struct bt_bmc *bt_bmc = file_bt_bmc(file);
> +       unsigned int mask = 0;
> +       uint8_t ctrl;
> +
> +       poll_wait(file, &bt_bmc->queue, wait);
> +
> +       ctrl = bt_inb(bt_bmc, BT_CTRL);
> +
> +       if (ctrl & BT_CTRL_H2B_ATN)
> +               mask |= POLLIN;
> +
> +       if (!(ctrl & (BT_CTRL_H_BUSY | BT_CTRL_B2H_ATN)))
> +               mask |= POLLOUT;
> +
> +       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(unsigned long data)
> +{
> +       struct bt_bmc *bt_bmc = (void *)data;
> +
> +       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;
> +       uint32_t reg;
> +
> +       reg = ioread32(bt_bmc->base + BT_CR2);
> +       reg &= BT_CR2_IRQ_H2B | BT_CR2_IRQ_HBUSY;
> +       if (!reg)
> +               return IRQ_NONE;
> +
> +       /* ack pending IRQs */
> +       iowrite32(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;
> +       uint32_t reg;
> +       int rc;
> +
> +       bt_bmc->irq = platform_get_irq(pdev, 0);
> +       if (!bt_bmc->irq)
> +               return -ENODEV;
> +
> +       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 = 0;
> +               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 = ioread32(bt_bmc->base + BT_CR1);
> +       reg |= BT_CR1_IRQ_H2B | BT_CR1_IRQ_HBUSY;
> +       iowrite32(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;
> +       struct resource *res;
> +       int rc;
> +
> +       if (!pdev || !pdev->dev.of_node)
> +               return -ENODEV;
> +
> +       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);
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res) {
> +               dev_err(dev, "Unable to find resources\n");
> +               rc = -ENXIO;
> +               goto out_free;
> +       }
> +
> +       bt_bmc->base = devm_ioremap_resource(&pdev->dev, res);
> +       if (!bt_bmc->base) {
> +               rc = -ENOMEM;
> +               goto out_free;
> +       }
> +
> +       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 device\n");
> +               goto out_unmap;
> +       }
> +
> +       bt_bmc_config_irq(bt_bmc, pdev);
> +
> +       if (bt_bmc->irq) {
> +               dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);
> +       } else {
> +               dev_info(dev, "No IRQ; using timer\n");
> +               setup_timer(&bt_bmc->poll_timer, poll_timer,
> +                               (unsigned long)bt_bmc);
> +               bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10);
> +               add_timer(&bt_bmc->poll_timer);
> +       }
> +
> +       iowrite32((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;
> +
> +out_unmap:
> +       devm_iounmap(&pdev->dev, bt_bmc->base);
> +
> +out_free:
> +       devm_kfree(dev, bt_bmc);
> +       return rc;
> +
> +}
> +
> +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)
> +               del_timer_sync(&bt_bmc->poll_timer);
> +       devm_iounmap(&pdev->dev, bt_bmc->base);
> +       devm_kfree(&pdev->dev, bt_bmc);
> +       bt_bmc = NULL;
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id bt_bmc_match[] = {
> +       { .compatible = "aspeed,bt-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 BT interface");
> diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
> index ec10cfef166a..9493842de93b 100644
> --- a/include/uapi/linux/Kbuild
> +++ b/include/uapi/linux/Kbuild
> @@ -74,6 +74,7 @@ header-y += bpf_common.h
>  header-y += bpf.h
>  header-y += bpqether.h
>  header-y += bsg.h
> +header-y += bt-bmc.h
>  header-y += btrfs.h
>  header-y += can.h
>  header-y += capability.h
> diff --git a/include/uapi/linux/bt-bmc.h b/include/uapi/linux/bt-bmc.h
> new file mode 100644
> index 000000000000..d9ec766a63d0
> --- /dev/null
> +++ b/include/uapi/linux/bt-bmc.h
> @@ -0,0 +1,18 @@
> +/*
> + * Copyright (c) 2015-2016, 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.
> + */
> +
> +#ifndef _UAPI_LINUX_BT_BMC_H
> +#define _UAPI_LINUX_BT_BMC_H
> +
> +#include <linux/ioctl.h>
> +
> +#define __BT_BMC_IOCTL_MAGIC   0xb1
> +#define BT_BMC_IOCTL_SMS_ATN   _IO(__BT_BMC_IOCTL_MAGIC, 0x00)
> +
> +#endif /* _UAPI_LINUX_BT_BMC_H */
> --
> 2.7.4
>

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Cédric Le Goater]

On 09/15/2016 09:09 AM, Joel Stanley wrote:
> On Thu, Sep 15, 2016 at 4:02 PM, Cédric Le Goater <clg@kaod.org> wrote:
>> From: Alistair Popple <alistair@popple.id.au>
>>
>> This patch adds a simple device driver to expose the iBT interface on
>> Aspeed SOCs (AST2400 and AST2500) as a character device :
>> /dev/ipmi-bt-bmc.
>>
>> The BT (Block Transfer) interface is used to perform in-band IPMI
>> communication from a BMC to the host. Entire messages are buffered
>> before sending a notification to the host, or the BMC when on the
>> other side, that there is data to be read. The driver implements the
>> BMC side of the BT interface.
>>
>> Signed-off-by: Alistair Popple <alistair@popple.id.au>
>> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
>> Signed-off-by: Joel Stanley <joel@jms.id.au>
>> [clg: - did some checkpatch fixes
>>       - added a devicetree binding documentation
>>       - renamed 'bt_host' to 'bt_bmc' to reflect that the driver is
>>         the BMC side of the IPMI BT interface
>>       - remaned the device name to 'ipmi-bt-bmc'
> 
> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
> device?

Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes 
more sense or just '/dev/ipmi-bt' because we won't have multiple hosts
to control.

C.

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Cédric Le Goater]

>> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
>> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
>> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
>> device?
> 
> Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes 

I meant /dev/ipmi-bt-host ! :)

C.

> more sense or just '/dev/ipmi-bt' because we won't have multiple hosts
> to control.
> 
> C.
> 
> _______________________________________________
> openbmc mailing list
> openbmc@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/openbmc
> 

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Joel Stanley]

On Thu, Sep 15, 2016 at 6:06 PM, Cédric Le Goater <clg@kaod.org> wrote:
>>> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
>>> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
>>> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
>>> device?
>>
>> Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes
>
> I meant /dev/ipmi-bt-host ! :)

Hah good! I didn't follow at all. That makes a lot more sense.

Thanks for sending the patches out. I will hold off applying them
until you've got support from upstream.

Cheers,

Joel

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Cédric Le Goater]

On 09/15/2016 12:03 PM, Joel Stanley wrote:
> On Thu, Sep 15, 2016 at 6:06 PM, Cédric Le Goater <clg@kaod.org> wrote:
>>>> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
>>>> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
>>>> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
>>>> device?
>>>
>>> Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes
>>
>> I meant /dev/ipmi-bt-host ! :)
> 
> Hah good! I didn't follow at all. That makes a lot more sense.
>
> Thanks for sending the patches out. I will hold off applying them
> until you've got support from upstream.

yes. This is better. I am realizing that I will have to change 
the ipmi Makefile, so the location of the driver is not certain 
yet.

C.

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Patrick Williams]

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On Thu, Sep 15, 2016 at 10:36:46AM +0200, Cédric Le Goater wrote:
> >> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
> >> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
> >> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
> >> device?
> > 
> > Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes 
> 
> I meant /dev/ipmi-bt-host ! :)

Does it make sense to have these numbered?  I thought Brenden proposed
an emulated bt-over-i2c.  We could also conceive of an SOC that had
multiple LPC (+bt) engines to facilitate multiple nodes, or an off-board
FPGA to do it.

-- 
Patrick Williams

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Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Cédric Le Goater]

On 09/15/2016 12:51 PM, Patrick Williams wrote:
> On Thu, Sep 15, 2016 at 10:36:46AM +0200, Cédric Le Goater wrote:
>>>> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
>>>> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
>>>> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
>>>> device?
>>>
>>> Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes 
>>
>> I meant /dev/ipmi-bt-host ! :)
> 
> Does it make sense to have these numbered?  I thought Brenden proposed
> an emulated bt-over-i2c.  We could also conceive of an SOC that had
> multiple LPC (+bt) engines to facilitate multiple nodes, or an off-board
> FPGA to do it.
> 

If we expect to have multiple btbridged process running, we will 
need multiple device nodes. How we should name them depends partly 
on the driver I think. 

We could keep the prefix 'ipmi-bt' because it identifies the BT 
interface described in the IPMI specs and use node /dev/ipmi-bt-host 
for the original bt_bmc, (used be bt_host) driver. This one will be 
unique. 

The others could use : 
	
		/dev/ipmi-bt-lpc
		/dev/ipmi-bt-i2c-<bus>


?


C.

Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Patrick Williams]

[-- Attachment #1: Type: text/plain, Size: 1469 bytes --]

On Thu, Sep 15, 2016 at 01:22:50PM +0200, Cédric Le Goater wrote:
> On 09/15/2016 12:51 PM, Patrick Williams wrote:
> > On Thu, Sep 15, 2016 at 10:36:46AM +0200, Cédric Le Goater wrote:
> >>>> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
> >>>> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
> >>>> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
> >>>> device?
> >>>
> >>> Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes 
> >>
> >> I meant /dev/ipmi-bt-host ! :)
> > 
> > Does it make sense to have these numbered?  I thought Brenden proposed
> > an emulated bt-over-i2c.  We could also conceive of an SOC that had
> > multiple LPC (+bt) engines to facilitate multiple nodes, or an off-board
> > FPGA to do it.
> > 
> 
> If we expect to have multiple btbridged process running, we will 
> need multiple device nodes. How we should name them depends partly 
> on the driver I think. 
> 
> We could keep the prefix 'ipmi-bt' because it identifies the BT 
> interface described in the IPMI specs and use node /dev/ipmi-bt-host 
> for the original bt_bmc, (used be bt_host) driver. This one will be 
> unique. 
> 
> The others could use : 
> 	
> 		/dev/ipmi-bt-lpc
> 		/dev/ipmi-bt-i2c-<bus>

I was thinking along the lines of /dev/ipmi-bt-hostN.  Maybe we do this
through udev rules though?

> 
> 
> ?
> 
> 
> C.

-- 
Patrick Williams

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Re: [RFC PATCH linux dev-4.7 4/6] misc: Add Aspeed BT IPMI BMC driver

[Cédric Le Goater]

On 09/15/2016 01:33 PM, Patrick Williams wrote:
> On Thu, Sep 15, 2016 at 01:22:50PM +0200, Cédric Le Goater wrote:
>> On 09/15/2016 12:51 PM, Patrick Williams wrote:
>>> On Thu, Sep 15, 2016 at 10:36:46AM +0200, Cédric Le Goater wrote:
>>>>>> I'm not sure there. When I open /dev/ttyUSB0 I'm talking to the USB0
>>>>>> serial device. When I open /dev/mtd0, I'm talking to the mtd0 device.
>>>>>> So when I open /dev/ipmi-bt-bmc, I would expect to talk to the BMC
>>>>>> device?
>>>>>
>>>>> Yes. I went a little too far in the global rename. /dev/ipmi-bt-bmc makes 
>>>>
>>>> I meant /dev/ipmi-bt-host ! :)
>>>
>>> Does it make sense to have these numbered?  I thought Brenden proposed
>>> an emulated bt-over-i2c.  We could also conceive of an SOC that had
>>> multiple LPC (+bt) engines to facilitate multiple nodes, or an off-board
>>> FPGA to do it.
>>>
>>
>> If we expect to have multiple btbridged process running, we will 
>> need multiple device nodes. How we should name them depends partly 
>> on the driver I think. 
>>
>> We could keep the prefix 'ipmi-bt' because it identifies the BT 
>> interface described in the IPMI specs and use node /dev/ipmi-bt-host 
>> for the original bt_bmc, (used be bt_host) driver. This one will be 
>> unique. 
>>
>> The others could use : 
>> 	
>> 		/dev/ipmi-bt-lpc
>> 		/dev/ipmi-bt-i2c-<bus>
> 
> I was thinking along the lines of /dev/ipmi-bt-hostN.  Maybe we do this
> through udev rules though?

yes. this look like the best approach. 

C.

[RFC PATCH linux dev-4.7 5/6] ARM: aspeed: Add defconfigs for CONFIG_ASPEED_BT_IPMI_BMC

[Cédric Le Goater]

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/arm/configs/aspeed_g4_defconfig | 2 ++
 arch/arm/configs/aspeed_g5_defconfig | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/arm/configs/aspeed_g4_defconfig b/arch/arm/configs/aspeed_g4_defconfig
index fab53889b2cc..5a1281257a49 100644
--- a/arch/arm/configs/aspeed_g4_defconfig
+++ b/arch/arm/configs/aspeed_g4_defconfig
@@ -100,6 +100,8 @@ CONFIG_SERIAL_8250_RUNTIME_UARTS=6
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_IPMI_HANDLER=y
+CONFIG_ASPEED_BT_IPMI_BMC=y
 CONFIG_SERIAL_ASPEED_VUART=y
 # CONFIG_HW_RANDOM is not set
 CONFIG_I2C=y
diff --git a/arch/arm/configs/aspeed_g5_defconfig b/arch/arm/configs/aspeed_g5_defconfig
index 3ccc91db96e3..dd171ac90bbd 100644
--- a/arch/arm/configs/aspeed_g5_defconfig
+++ b/arch/arm/configs/aspeed_g5_defconfig
@@ -102,6 +102,8 @@ CONFIG_SERIAL_8250_RUNTIME_UARTS=6
 CONFIG_SERIAL_8250_EXTENDED=y
 CONFIG_SERIAL_8250_SHARE_IRQ=y
 CONFIG_SERIAL_OF_PLATFORM=y
+CONFIG_IPMI_HANDLER=y
+CONFIG_ASPEED_BT_IPMI_BMC=y
 CONFIG_SERIAL_ASPEED_VUART=y
 # CONFIG_HW_RANDOM is not set
 CONFIG_I2C=y
-- 
2.7.4

[RFC PATCH linux dev-4.7 6/6] ARM: dts: aspeed: Enable BT IPMI BMC device

[Cédric Le Goater]

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 arch/arm/boot/dts/aspeed-g4.dtsi | 6 ++++++
 arch/arm/boot/dts/aspeed-g5.dtsi | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi
index eb0122fa34c2..4480b858103e 100644
--- a/arch/arm/boot/dts/aspeed-g4.dtsi
+++ b/arch/arm/boot/dts/aspeed-g4.dtsi
@@ -391,6 +391,12 @@
 				clocks = <&clk_apb>;
 			};
 
+			ibt: ibt@1e789140 {
+				compatible = "aspeed,bt-bmc";
+				reg = <0x1e789140 0x18>;
+				interrupts = <8>;
+			};
+
 			wdt1: wdt@1e785000 {
 				compatible = "aspeed,ast2400-wdt";
 				reg = <0x1e785000 0x1c>;
diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi
index 79abac876abf..7c781fb613f8 100644
--- a/arch/arm/boot/dts/aspeed-g5.dtsi
+++ b/arch/arm/boot/dts/aspeed-g5.dtsi
@@ -255,6 +255,12 @@
 				clocks = <&clk_apb>;
 			};
 
+			ibt: ibt@1e789140 {
+				compatible = "aspeed,bt-bmc";
+				reg = <0x1e789140 0x18>;
+				interrupts = <8>;
+			};
+
 			wdt1: wdt@1e785000 {
 				compatible = "aspeed,ast2500-wdt";
 				reg = <0x1e785000 0x1c>;
-- 
2.7.4

Re: [RFC PATCH linux dev-4.7 6/6] ARM: dts: aspeed: Enable BT IPMI BMC device

[Joel Stanley]

On Thu, Sep 15, 2016 at 4:02 PM, Cédric Le Goater <clg@kaod.org> wrote:
> Signed-off-by: Cédric Le Goater <clg@kaod.org>
> ---
>  arch/arm/boot/dts/aspeed-g4.dtsi | 6 ++++++
>  arch/arm/boot/dts/aspeed-g5.dtsi | 6 ++++++
>  2 files changed, 12 insertions(+)
>
> diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi
> index eb0122fa34c2..4480b858103e 100644
> --- a/arch/arm/boot/dts/aspeed-g4.dtsi
> +++ b/arch/arm/boot/dts/aspeed-g4.dtsi
> @@ -391,6 +391,12 @@
>                                 clocks = <&clk_apb>;
>                         };
>
> +                       ibt: ibt@1e789140 {

Given this is part of the LPC register set, and we need to expose
other parts of the LPC, I was wondering if we wanted to make this a
sub-node of a mfd device that covered all of the LPC controller's
registers. What do you think?

> +                               compatible = "aspeed,bt-bmc";

When getting bindings reviewed I've been told we should have something
soc specific in the string, like aspeed,ast2400-bt-bmc. I'm to too
fussed though.

> +                               reg = <0x1e789140 0x18>;
> +                               interrupts = <8>;
> +                       };
> +
>                         wdt1: wdt@1e785000 {
>                                 compatible = "aspeed,ast2400-wdt";
>                                 reg = <0x1e785000 0x1c>;
> diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi
> index 79abac876abf..7c781fb613f8 100644
> --- a/arch/arm/boot/dts/aspeed-g5.dtsi
> +++ b/arch/arm/boot/dts/aspeed-g5.dtsi
> @@ -255,6 +255,12 @@
>                                 clocks = <&clk_apb>;
>                         };
>
> +                       ibt: ibt@1e789140 {
> +                               compatible = "aspeed,bt-bmc";
> +                               reg = <0x1e789140 0x18>;
> +                               interrupts = <8>;
> +                       };
> +
>                         wdt1: wdt@1e785000 {
>                                 compatible = "aspeed,ast2500-wdt";
>                                 reg = <0x1e785000 0x1c>;
> --
> 2.7.4
>

Re: [RFC PATCH linux dev-4.7 6/6] ARM: dts: aspeed: Enable BT IPMI BMC device

[Cédric Le Goater]

On 09/15/2016 09:11 AM, Joel Stanley wrote:
> On Thu, Sep 15, 2016 at 4:02 PM, Cédric Le Goater <clg@kaod.org> wrote:
>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>> ---
>>  arch/arm/boot/dts/aspeed-g4.dtsi | 6 ++++++
>>  arch/arm/boot/dts/aspeed-g5.dtsi | 6 ++++++
>>  2 files changed, 12 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi b/arch/arm/boot/dts/aspeed-g4.dtsi
>> index eb0122fa34c2..4480b858103e 100644
>> --- a/arch/arm/boot/dts/aspeed-g4.dtsi
>> +++ b/arch/arm/boot/dts/aspeed-g4.dtsi
>> @@ -391,6 +391,12 @@
>>                                 clocks = <&clk_apb>;
>>                         };
>>
>> +                       ibt: ibt@1e789140 {
> 
> Given this is part of the LPC register set, and we need to expose
> other parts of the LPC, I was wondering if we wanted to make this a
> sub-node of a mfd device that covered all of the LPC controller's
> registers. What do you think?

It will be cleaner. We don't have to put all of it right now.

>> +                               compatible = "aspeed,bt-bmc";
> 
> When getting bindings reviewed I've been told we should have something
> soc specific in the string, like aspeed,ast2400-bt-bmc. I'm to too
> fussed though.

yes, this is frequent, something like :

          compatible = "aspeed,bt-bmc", "aspeed,ast2400-bt-bmc";

Thanks,
C.

>> +                               reg = <0x1e789140 0x18>;
>> +                               interrupts = <8>;
>> +                       };
>> +
>>                         wdt1: wdt@1e785000 {
>>                                 compatible = "aspeed,ast2400-wdt";
>>                                 reg = <0x1e785000 0x1c>;
>> diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi
>> index 79abac876abf..7c781fb613f8 100644
>> --- a/arch/arm/boot/dts/aspeed-g5.dtsi
>> +++ b/arch/arm/boot/dts/aspeed-g5.dtsi
>> @@ -255,6 +255,12 @@
>>                                 clocks = <&clk_apb>;
>>                         };
>>
>> +                       ibt: ibt@1e789140 {
>> +                               compatible = "aspeed,bt-bmc";
>> +                               reg = <0x1e789140 0x18>;
>> +                               interrupts = <8>;
>> +                       };
>> +
>>                         wdt1: wdt@1e785000 {
>>                                 compatible = "aspeed,ast2500-wdt";
>>                                 reg = <0x1e785000 0x1c>;
>> --
>> 2.7.4
>>

Re: [RFC PATCH linux dev-4.7 0/6] iBT interface changes

[Joel Stanley]

Hi Cedric,

On Thu, Sep 15, 2016 at 4:02 PM, Cédric Le Goater <clg@kaod.org> wrote:
> Hello,
>
> This patchset introduces a couple of changes on the driver for the iBT
> interface on Aspeed SOCs. These were suggested by mainline and have
> some conficts with the OpenBMC userspace. The most important are name
> changes, which impact the btbridge daemon, but nothing is requiring a
> redesign of the stack.
>
> The previous driver is reverted and and reincluded in its mainline
> form. So you should mostly check patch 4 and quickly 5,6. The merge
> in openbmc kernel can wait mainline's green light I think.

Congratulations on getting the bt driver upstream. Another one crossed
off the list (https://github.com/openbmc/linux/wiki).

What are your thoughts on integrating the change in the OpenBMC tree?

With the release of v4.8 around the corner I was thinking we could
move to a dev-4.8 tree, and move to your driver then. This would give
us a chance to synchronise all of the patches with their upstream
versions (gpio, watchdog, bt, pinmux).

Alternative proposals are welcome.

Cheers,

Joel

> You can find the btbridge changes:
>
>      https://github.com/legoater/btbridge
>
> Thanks,
>
> C.
>
>
> Alistair Popple (1):
>   misc: Add Aspeed BT IPMI BMC driver
>
> Cédric Le Goater (5):
>   Revert "misc: Add Aspeed BT IPMI host driver"
>   ARM: aspeed: remove previous definitions in default config
>   ARM: dts: aspeed: remove previous iBT definitions
>   ARM: aspeed: Add defconfigs for CONFIG_ASPEED_BT_IPMI_BMC
>   ARM: dts: aspeed: Enable BT IPMI BMC device
>
>  .../bindings/char/ipmi/aspeed,bt-bmc.txt           |  19 +
>  arch/arm/boot/dts/aspeed-g4.dtsi                   |   2 +-
>  arch/arm/boot/dts/aspeed-g5.dtsi                   |   2 +-
>  arch/arm/configs/aspeed_g4_defconfig               |   3 +-
>  arch/arm/configs/aspeed_g5_defconfig               |   3 +-
>  drivers/char/ipmi/Kconfig                          |   7 +
>  drivers/char/ipmi/Makefile                         |   1 +
>  drivers/char/ipmi/bt-bmc.c                         | 475 +++++++++++++++++++++
>  drivers/misc/Kconfig                               |   5 -
>  drivers/misc/Makefile                              |   1 -
>  drivers/misc/bt-host.c                             | 427 ------------------
>  include/uapi/linux/Kbuild                          |   2 +-
>  include/uapi/linux/{bt-host.h => bt-bmc.h}         |  12 +-
>  13 files changed, 515 insertions(+), 444 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/char/ipmi/aspeed,bt-bmc.txt
>  create mode 100644 drivers/char/ipmi/bt-bmc.c
>  delete mode 100644 drivers/misc/bt-host.c
>  rename include/uapi/linux/{bt-host.h => bt-bmc.h} (55%)
>
> --
> 2.7.4
>

Re: [RFC PATCH linux dev-4.7 0/6] iBT interface changes

[Cédric Le Goater]

Hello,

On 09/23/2016 08:14 AM, Joel Stanley wrote:
> Hi Cedric,
> 
> On Thu, Sep 15, 2016 at 4:02 PM, Cédric Le Goater <clg@kaod.org> wrote:
>> Hello,
>>
>> This patchset introduces a couple of changes on the driver for the iBT
>> interface on Aspeed SOCs. These were suggested by mainline and have
>> some conficts with the OpenBMC userspace. The most important are name
>> changes, which impact the btbridge daemon, but nothing is requiring a
>> redesign of the stack.
>>
>> The previous driver is reverted and and reincluded in its mainline
>> form. So you should mostly check patch 4 and quickly 5,6. The merge
>> in openbmc kernel can wait mainline's green light I think.
> 
> Congratulations on getting the bt driver upstream. Another one crossed
> off the list (https://github.com/openbmc/linux/wiki).
> 
> What are your thoughts on integrating the change in the OpenBMC tree?

I have been using it on palmetto without issues. We will need a new 
btbridged for that :

	https://github.com/legoater/btbridge

I would also like to add an extension adding a request expiry list
which is in the IPMI spec. Getting some exposure would be good, so 
that we can test and discuss on the feature. 

> With the release of v4.8 around the corner I was thinking we could
> move to a dev-4.8 tree, and move to your driver then. This would give
> us a chance to synchronise all of the patches with their upstream
> versions (gpio, watchdog, bt, pinmux).

+1

Thanks,

C.