1 // SPDX-License-Identifier: GPL-2.0+
10  * Provides a simple driver to control the ASPEED P2A interface which allows
28 #include <linux/aspeed-p2a-ctrl.h>
30 #define DEVICE_NAME	"aspeed-p2a-ctrl"
32 /* SCU2C is a Misc. Control Register. */
34 /* SCU180 is the PCIe Configuration Setting Control Register. */
74 	struct aspeed_p2a_ctrl *parent;  member
91 	regmap_update_bits(p2a_ctrl->regmap,  in aspeed_p2a_enable_bridge()
97 	regmap_update_bits(p2a_ctrl->regmap, SCU180, SCU180_ENP2A, 0);  in aspeed_p2a_disable_bridge()
104 	struct aspeed_p2a_user *priv = file->private_data;  in aspeed_p2a_mmap()
105 	struct aspeed_p2a_ctrl *ctrl = priv->parent;  in aspeed_p2a_mmap()
107 	if (ctrl->mem_base == 0 && ctrl->mem_size == 0)  in aspeed_p2a_mmap()
108 		return -EINVAL;  in aspeed_p2a_mmap()
110 	vsize = vma->vm_end - vma->vm_start;  in aspeed_p2a_mmap()
111 	prot = vma->vm_page_prot;  in aspeed_p2a_mmap()
113 	if (vma->vm_pgoff + vsize > ctrl->mem_base + ctrl->mem_size)  in aspeed_p2a_mmap()
114 		return -EINVAL;  in aspeed_p2a_mmap()
119 	if (remap_pfn_range(vma, vma->vm_start,  in aspeed_p2a_mmap()
120 		(ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff,  in aspeed_p2a_mmap()
122 		return -EAGAIN;  in aspeed_p2a_mmap()
135 	base = map->addr;  in aspeed_p2a_region_acquire()
136 	end = map->addr + (map->length - 1);  in aspeed_p2a_region_acquire()
140 		const struct region *curr = &ctrl->config->regions[i];  in aspeed_p2a_region_acquire()
144 		if (curr->max < base)  in aspeed_p2a_region_acquire()
149 		if (curr->min > end)  in aspeed_p2a_region_acquire()
155 		mutex_lock(&ctrl->tracking);  in aspeed_p2a_region_acquire()
156 		ctrl->readerwriters[i] += 1;  in aspeed_p2a_region_acquire()
157 		mutex_unlock(&ctrl->tracking);  in aspeed_p2a_region_acquire()
162 		priv->readwrite[i] += 1;  in aspeed_p2a_region_acquire()
164 		/* Enable the region as read-write. */  in aspeed_p2a_region_acquire()
165 		regmap_update_bits(ctrl->regmap, SCU2C, curr->bit, 0);  in aspeed_p2a_region_acquire()
175 	struct aspeed_p2a_user *priv = file->private_data;  in aspeed_p2a_ioctl()
176 	struct aspeed_p2a_ctrl *ctrl = priv->parent;  in aspeed_p2a_ioctl()
181 		return -EFAULT;  in aspeed_p2a_ioctl()
185 		/* If they want a region to be read-only, since the entire  in aspeed_p2a_ioctl()
186 		 * region is read-only once enabled, we just need to track this  in aspeed_p2a_ioctl()
191 			mutex_lock(&ctrl->tracking);  in aspeed_p2a_ioctl()
192 			ctrl->readers += 1;  in aspeed_p2a_ioctl()
193 			mutex_unlock(&ctrl->tracking);  in aspeed_p2a_ioctl()
198 			priv->read += 1;  in aspeed_p2a_ioctl()
202 				return -EINVAL;  in aspeed_p2a_ioctl()
206 			return -EINVAL;  in aspeed_p2a_ioctl()
212 		/* This is a request for the memory-region and corresponding  in aspeed_p2a_ioctl()
217 		map.addr = ctrl->mem_base;  in aspeed_p2a_ioctl()
218 		map.length = ctrl->mem_size;  in aspeed_p2a_ioctl()
220 		return copy_to_user(arg, &map, sizeof(map)) ? -EFAULT : 0;  in aspeed_p2a_ioctl()
223 	return -EINVAL;  in aspeed_p2a_ioctl()
230  * A user can map a region as read-only (bridge enabled), or read-write (bit
243 		return -ENOMEM;  in aspeed_p2a_open()
245 	priv->file = file;  in aspeed_p2a_open()
246 	priv->read = 0;  in aspeed_p2a_open()
247 	memset(priv->readwrite, 0, sizeof(priv->readwrite));  in aspeed_p2a_open()
250 	priv->parent = file->private_data;  in aspeed_p2a_open()
253 	file->private_data = priv;  in aspeed_p2a_open()
268 	struct aspeed_p2a_user *priv = file->private_data;  in aspeed_p2a_release()
273 	mutex_lock(&priv->parent->tracking);  in aspeed_p2a_release()
275 	priv->parent->readers -= priv->read;  in aspeed_p2a_release()
278 		priv->parent->readerwriters[i] -= priv->readwrite[i];  in aspeed_p2a_release()
280 		if (priv->parent->readerwriters[i] > 0)  in aspeed_p2a_release()
283 			bits |= priv->parent->config->regions[i].bit;  in aspeed_p2a_release()
294 	regmap_update_bits(priv->parent->regmap, SCU2C, bits, bits);  in aspeed_p2a_release()
296 	/* If parent->readers is zero and open windows is 0, disable the  in aspeed_p2a_release()
299 	if (!open_regions && priv->parent->readers == 0)  in aspeed_p2a_release()
300 		aspeed_p2a_disable_bridge(priv->parent);  in aspeed_p2a_release()
302 	mutex_unlock(&priv->parent->tracking);  in aspeed_p2a_release()
324 		value |= p2a_ctrl->config->regions[i].bit;  in aspeed_p2a_disable_all()
326 	regmap_update_bits(p2a_ctrl->regmap, SCU2C, value, value);  in aspeed_p2a_disable_all()
340 	dev = &pdev->dev;  in aspeed_p2a_ctrl_probe()
344 		return -ENOMEM;  in aspeed_p2a_ctrl_probe()
346 	mutex_init(&misc_ctrl->tracking);  in aspeed_p2a_ctrl_probe()
349 	node = of_parse_phandle(dev->of_node, "memory-region", 0);  in aspeed_p2a_ctrl_probe()
355 			return -ENODEV;  in aspeed_p2a_ctrl_probe()
358 		misc_ctrl->mem_size = resource_size(&resm);  in aspeed_p2a_ctrl_probe()
359 		misc_ctrl->mem_base = resm.start;  in aspeed_p2a_ctrl_probe()
362 	misc_ctrl->regmap = syscon_node_to_regmap(pdev->dev.parent->of_node);  in aspeed_p2a_ctrl_probe()
363 	if (IS_ERR(misc_ctrl->regmap)) {  in aspeed_p2a_ctrl_probe()
365 		return -ENODEV;  in aspeed_p2a_ctrl_probe()
368 	misc_ctrl->config = of_device_get_match_data(dev);  in aspeed_p2a_ctrl_probe()
370 	dev_set_drvdata(&pdev->dev, misc_ctrl);  in aspeed_p2a_ctrl_probe()
374 	misc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR;  in aspeed_p2a_ctrl_probe()
375 	misc_ctrl->miscdev.name = DEVICE_NAME;  in aspeed_p2a_ctrl_probe()
376 	misc_ctrl->miscdev.fops = &aspeed_p2a_ctrl_fops;  in aspeed_p2a_ctrl_probe()
377 	misc_ctrl->miscdev.parent = dev;  in aspeed_p2a_ctrl_probe()
379 	rc = misc_register(&misc_ctrl->miscdev);  in aspeed_p2a_ctrl_probe()
388 	struct aspeed_p2a_ctrl *p2a_ctrl = dev_get_drvdata(&pdev->dev);  in aspeed_p2a_ctrl_remove()
390 	misc_deregister(&p2a_ctrl->miscdev);  in aspeed_p2a_ctrl_remove()
423 	{ .compatible = "aspeed,ast2400-p2a-ctrl",
425 	{ .compatible = "aspeed,ast2500-p2a-ctrl",
444 MODULE_DESCRIPTION("Control for aspeed 2400/2500 P2A VGA HOST to BMC mappings");