/* * Copyright 2017 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/mfd/syscon.h>#include <linux/miscdevice.h>#include <linux/mm.h>#include <linux/module.h>#include <linux/of_address.h>#include <linux/platform_device.h>#include <linux/poll.h>#include <linux/regmap.h> #include <linux/aspeed-lpc-ctrl.h> #define DEVICE_NAME	"aspeed-lpc-ctrl" #define HICR7 0x8#define HICR8 0xc struct aspeed_lpc_ctrl {	struct miscdevice	miscdev;	struct regmap		*regmap;	phys_addr_t		mem_base;	resource_size_t		mem_size;	u32		pnor_size;	u32		pnor_base;}; static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file){	return container_of(file->private_data, struct aspeed_lpc_ctrl,			miscdev);} static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma){	struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file);	unsigned long vsize = vma->vm_end - vma->vm_start;	pgprot_t prot = vma->vm_page_prot; 	if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size)		return -EINVAL; 	/* ast2400/2500 AHB accesses are not cache coherent */	prot = pgprot_noncached(prot); 	if (remap_pfn_range(vma, vma->vm_start,		(lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff,		vsize, prot))		return -EAGAIN; 	return 0;} static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd,		unsigned long param){	struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file);	void __user *p = (void __user *)param;	struct aspeed_lpc_ctrl_mapping map;	u32 addr;	u32 size;	long rc; 	if (copy_from_user(&map, p, sizeof(map)))		return -EFAULT; 	if (map.flags != 0)		return -EINVAL; 	switch (cmd) {	case ASPEED_LPC_CTRL_IOCTL_GET_SIZE:		/* The flash windows don't report their size */		if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY)			return -EINVAL; 		/* Support more than one window id in the future */		if (map.window_id != 0)			return -EINVAL; 		map.size = lpc_ctrl->mem_size; 		return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0;	case ASPEED_LPC_CTRL_IOCTL_MAP: 		/*		 * The top half of HICR7 is the MSB of the BMC address of the		 * mapping.		 * The bottom half of HICR7 is the MSB of the HOST LPC		 * firmware space address of the mapping.		 *		 * The 1 bits in the top of half of HICR8 represent the bits		 * (in the requested address) that should be ignored and		 * replaced with those from the top half of HICR7.		 * The 1 bits in the bottom half of HICR8 represent the bits		 * (in the requested address) that should be kept and pass		 * into the BMC address space.		 */ 		/*		 * It doesn't make sense to talk about a size or offset with		 * low 16 bits set. Both HICR7 and HICR8 talk about the top 16		 * bits of addresses and sizes.		 */ 		if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff))			return -EINVAL; 		/*		 * Because of the way the masks work in HICR8 offset has to		 * be a multiple of size.		 */		if (map.offset & (map.size - 1))			return -EINVAL; 		if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) {			addr = lpc_ctrl->pnor_base;			size = lpc_ctrl->pnor_size;		} else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) {			addr = lpc_ctrl->mem_base;			size = lpc_ctrl->mem_size;		} else {			return -EINVAL;		} 		/* Check overflow first! */		if (map.offset + map.size < map.offset ||			map.offset + map.size > size)			return -EINVAL; 		if (map.size == 0 || map.size > size)			return -EINVAL; 		addr += map.offset; 		/*		 * addr (host lpc address) is safe regardless of values. This		 * simply changes the address the host has to request on its		 * side of the LPC bus. This cannot impact the hosts own		 * memory space by surprise as LPC specific accessors are		 * required. The only strange thing that could be done is		 * setting the lower 16 bits but the shift takes care of that.		 */ 		rc = regmap_write(lpc_ctrl->regmap, HICR7,				(addr | (map.addr >> 16)));		if (rc)			return rc; 		return regmap_write(lpc_ctrl->regmap, HICR8,			(~(map.size - 1)) | ((map.size >> 16) - 1));	} 	return -EINVAL;} static const struct file_operations aspeed_lpc_ctrl_fops = {	.owner		= THIS_MODULE,	.mmap		= aspeed_lpc_ctrl_mmap,	.unlocked_ioctl	= aspeed_lpc_ctrl_ioctl,}; static int aspeed_lpc_ctrl_probe(struct platform_device *pdev){	struct aspeed_lpc_ctrl *lpc_ctrl;	struct device_node *node;	struct resource resm;	struct device *dev;	int rc; 	dev = &pdev->dev; 	lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL);	if (!lpc_ctrl)		return -ENOMEM; 	node = of_parse_phandle(dev->of_node, "flash", 0);	if (!node) {		dev_err(dev, "Didn't find host pnor flash node\n");		return -ENODEV;	} 	rc = of_address_to_resource(node, 1, &resm);	of_node_put(node);	if (rc) {		dev_err(dev, "Couldn't address to resource for flash\n");		return rc;	} 	lpc_ctrl->pnor_size = resource_size(&resm);	lpc_ctrl->pnor_base = resm.start; 	dev_set_drvdata(&pdev->dev, lpc_ctrl); 	node = of_parse_phandle(dev->of_node, "memory-region", 0);	if (!node) {		dev_err(dev, "Didn't find reserved memory\n");		return -EINVAL;	} 	rc = of_address_to_resource(node, 0, &resm);	of_node_put(node);	if (rc) {		dev_err(dev, "Couldn't address to resource for reserved memory\n");		return -ENOMEM;	} 	lpc_ctrl->mem_size = resource_size(&resm);	lpc_ctrl->mem_base = resm.start; 	lpc_ctrl->regmap = syscon_node_to_regmap(			pdev->dev.parent->of_node);	if (IS_ERR(lpc_ctrl->regmap)) {		dev_err(dev, "Couldn't get regmap\n");		return -ENODEV;	} 	lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR;	lpc_ctrl->miscdev.name = DEVICE_NAME;	lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops;	lpc_ctrl->miscdev.parent = dev;	rc = misc_register(&lpc_ctrl->miscdev);	if (rc)		dev_err(dev, "Unable to register device\n");	else		dev_info(dev, "Loaded at %pr\n", &resm); 	return rc;} static int aspeed_lpc_ctrl_remove(struct platform_device *pdev){	struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); 	misc_deregister(&lpc_ctrl->miscdev); 	return 0;} static const struct of_device_id aspeed_lpc_ctrl_match[] = {	{ .compatible = "aspeed,ast2400-lpc-ctrl" },	{ .compatible = "aspeed,ast2500-lpc-ctrl" },	{ },}; static struct platform_driver aspeed_lpc_ctrl_driver = {	.driver = {		.name		= DEVICE_NAME,		.of_match_table = aspeed_lpc_ctrl_match,	},	.probe = aspeed_lpc_ctrl_probe,	.remove = aspeed_lpc_ctrl_remove,}; module_platform_driver(aspeed_lpc_ctrl_driver); MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match);MODULE_LICENSE("GPL");MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>");MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings");