1 // SPDX-License-Identifier: GPL-2.0+
3  * Copyright (c) 2015-2016, IBM Corporation.
7 #include <linux/bt-bmc.h>
22 #define DEVICE_NAME	"ipmi-bt-host"
71 	return readb(bt_bmc->base + reg);  in bt_inb()
76 	writeb(data, bt_bmc->base + reg);  in bt_outb()
146 	return container_of(file->private_data, struct bt_bmc, miscdev);  in file_bt_bmc()
159 	return -EBUSY;  in bt_bmc_open()
163  * The BT (Block Transfer) interface means that entire messages are
169  * BT Message format :
187 	if (wait_event_interruptible(bt_bmc->queue,  in bt_bmc_read()
189 		return -ERESTARTSYS;  in bt_bmc_read()
191 	mutex_lock(&bt_bmc->mutex);  in bt_bmc_read()
194 		ret = -EIO;  in bt_bmc_read()
203 	 * The BT frames start with the message length, which does not  in bt_bmc_read()
211 		len = count - 1;  in bt_bmc_read()
214 		nread = min_t(ssize_t, len, sizeof(kbuffer) - len_byte);  in bt_bmc_read()
219 			ret = -EFAULT;  in bt_bmc_read()
222 		len -= nread;  in bt_bmc_read()
231 	mutex_unlock(&bt_bmc->mutex);  in bt_bmc_read()
236  * BT Message response format :
253 		return -EINVAL;  in bt_bmc_write()
261 	if (wait_event_interruptible(bt_bmc->queue,  in bt_bmc_write()
264 		return -ERESTARTSYS;  in bt_bmc_write()
266 	mutex_lock(&bt_bmc->mutex);  in bt_bmc_write()
270 		ret = -EIO;  in bt_bmc_write()
279 			ret = -EFAULT;  in bt_bmc_write()
285 		count -= nwritten;  in bt_bmc_write()
293 	mutex_unlock(&bt_bmc->mutex);  in bt_bmc_write()
307 	return -EINVAL;  in bt_bmc_ioctl()
325 	poll_wait(file, &bt_bmc->queue, wait);  in bt_bmc_poll()
352 	bt_bmc->poll_timer.expires += msecs_to_jiffies(500);  in poll_timer()
353 	wake_up(&bt_bmc->queue);  in poll_timer()
354 	add_timer(&bt_bmc->poll_timer);  in poll_timer()
362 	reg = readl(bt_bmc->base + BT_CR2);  in bt_bmc_irq()
369 	writel(reg, bt_bmc->base + BT_CR2);  in bt_bmc_irq()
371 	wake_up(&bt_bmc->queue);  in bt_bmc_irq()
378 	struct device *dev = &pdev->dev;  in bt_bmc_config_irq()
382 	bt_bmc->irq = platform_get_irq_optional(pdev, 0);  in bt_bmc_config_irq()
383 	if (bt_bmc->irq < 0)  in bt_bmc_config_irq()
384 		return bt_bmc->irq;  in bt_bmc_config_irq()
386 	rc = devm_request_irq(dev, bt_bmc->irq, bt_bmc_irq, IRQF_SHARED,  in bt_bmc_config_irq()
389 		dev_warn(dev, "Unable to request IRQ %d\n", bt_bmc->irq);  in bt_bmc_config_irq()
390 		bt_bmc->irq = rc;  in bt_bmc_config_irq()
398 	 * message to the BT buffer  in bt_bmc_config_irq()
400 	reg = readl(bt_bmc->base + BT_CR1);  in bt_bmc_config_irq()
402 	writel(reg, bt_bmc->base + BT_CR1);  in bt_bmc_config_irq()
413 	dev = &pdev->dev;  in bt_bmc_probe()
414 	dev_info(dev, "Found bt bmc device\n");  in bt_bmc_probe()
418 		return -ENOMEM;  in bt_bmc_probe()
420 	dev_set_drvdata(&pdev->dev, bt_bmc);  in bt_bmc_probe()
422 	bt_bmc->base = devm_platform_ioremap_resource(pdev, 0);  in bt_bmc_probe()
423 	if (IS_ERR(bt_bmc->base))  in bt_bmc_probe()
424 		return PTR_ERR(bt_bmc->base);  in bt_bmc_probe()
426 	mutex_init(&bt_bmc->mutex);  in bt_bmc_probe()
427 	init_waitqueue_head(&bt_bmc->queue);  in bt_bmc_probe()
429 	bt_bmc->miscdev.minor	= MISC_DYNAMIC_MINOR;  in bt_bmc_probe()
430 	bt_bmc->miscdev.name	= DEVICE_NAME;  in bt_bmc_probe()
431 	bt_bmc->miscdev.fops	= &bt_bmc_fops;  in bt_bmc_probe()
432 	bt_bmc->miscdev.parent = dev;  in bt_bmc_probe()
433 	rc = misc_register(&bt_bmc->miscdev);  in bt_bmc_probe()
441 	if (bt_bmc->irq >= 0) {  in bt_bmc_probe()
442 		dev_info(dev, "Using IRQ %d\n", bt_bmc->irq);  in bt_bmc_probe()
445 		timer_setup(&bt_bmc->poll_timer, poll_timer, 0);  in bt_bmc_probe()
446 		bt_bmc->poll_timer.expires = jiffies + msecs_to_jiffies(10);  in bt_bmc_probe()
447 		add_timer(&bt_bmc->poll_timer);  in bt_bmc_probe()
455 		bt_bmc->base + BT_CR0);  in bt_bmc_probe()
464 	struct bt_bmc *bt_bmc = dev_get_drvdata(&pdev->dev);  in bt_bmc_remove()
466 	misc_deregister(&bt_bmc->miscdev);  in bt_bmc_remove()
467 	if (bt_bmc->irq < 0)  in bt_bmc_remove()
468 		del_timer_sync(&bt_bmc->poll_timer);  in bt_bmc_remove()
472 	{ .compatible = "aspeed,ast2400-ibt-bmc" },
473 	{ .compatible = "aspeed,ast2500-ibt-bmc" },
474 	{ .compatible = "aspeed,ast2600-ibt-bmc" },
492 MODULE_DESCRIPTION("Linux device interface to the IPMI BT interface");