1 /* 2 * Copyright 2017 IBM Corporation 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 #include <linux/clk.h> 11 #include <linux/mfd/syscon.h> 12 #include <linux/miscdevice.h> 13 #include <linux/mm.h> 14 #include <linux/module.h> 15 #include <linux/of_address.h> 16 #include <linux/platform_device.h> 17 #include <linux/poll.h> 18 #include <linux/regmap.h> 19 20 #include <linux/aspeed-lpc-ctrl.h> 21 22 #define DEVICE_NAME "aspeed-lpc-ctrl" 23 24 #define HICR5 0x0 25 #define HICR5_ENL2H BIT(8) 26 #define HICR5_ENFWH BIT(10) 27 28 #define HICR7 0x8 29 #define HICR8 0xc 30 31 struct aspeed_lpc_ctrl { 32 struct miscdevice miscdev; 33 struct regmap *regmap; 34 struct clk *clk; 35 phys_addr_t mem_base; 36 resource_size_t mem_size; 37 u32 pnor_size; 38 u32 pnor_base; 39 }; 40 41 static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) 42 { 43 return container_of(file->private_data, struct aspeed_lpc_ctrl, 44 miscdev); 45 } 46 47 static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) 48 { 49 struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); 50 unsigned long vsize = vma->vm_end - vma->vm_start; 51 pgprot_t prot = vma->vm_page_prot; 52 53 if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size) 54 return -EINVAL; 55 56 /* ast2400/2500 AHB accesses are not cache coherent */ 57 prot = pgprot_noncached(prot); 58 59 if (remap_pfn_range(vma, vma->vm_start, 60 (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, 61 vsize, prot)) 62 return -EAGAIN; 63 64 return 0; 65 } 66 67 static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, 68 unsigned long param) 69 { 70 struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); 71 void __user *p = (void __user *)param; 72 struct aspeed_lpc_ctrl_mapping map; 73 u32 addr; 74 u32 size; 75 long rc; 76 77 if (copy_from_user(&map, p, sizeof(map))) 78 return -EFAULT; 79 80 if (map.flags != 0) 81 return -EINVAL; 82 83 switch (cmd) { 84 case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: 85 /* The flash windows don't report their size */ 86 if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) 87 return -EINVAL; 88 89 /* Support more than one window id in the future */ 90 if (map.window_id != 0) 91 return -EINVAL; 92 93 map.size = lpc_ctrl->mem_size; 94 95 return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; 96 case ASPEED_LPC_CTRL_IOCTL_MAP: 97 98 /* 99 * The top half of HICR7 is the MSB of the BMC address of the 100 * mapping. 101 * The bottom half of HICR7 is the MSB of the HOST LPC 102 * firmware space address of the mapping. 103 * 104 * The 1 bits in the top of half of HICR8 represent the bits 105 * (in the requested address) that should be ignored and 106 * replaced with those from the top half of HICR7. 107 * The 1 bits in the bottom half of HICR8 represent the bits 108 * (in the requested address) that should be kept and pass 109 * into the BMC address space. 110 */ 111 112 /* 113 * It doesn't make sense to talk about a size or offset with 114 * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 115 * bits of addresses and sizes. 116 */ 117 118 if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) 119 return -EINVAL; 120 121 /* 122 * Because of the way the masks work in HICR8 offset has to 123 * be a multiple of size. 124 */ 125 if (map.offset & (map.size - 1)) 126 return -EINVAL; 127 128 if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { 129 addr = lpc_ctrl->pnor_base; 130 size = lpc_ctrl->pnor_size; 131 } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { 132 addr = lpc_ctrl->mem_base; 133 size = lpc_ctrl->mem_size; 134 } else { 135 return -EINVAL; 136 } 137 138 /* Check overflow first! */ 139 if (map.offset + map.size < map.offset || 140 map.offset + map.size > size) 141 return -EINVAL; 142 143 if (map.size == 0 || map.size > size) 144 return -EINVAL; 145 146 addr += map.offset; 147 148 /* 149 * addr (host lpc address) is safe regardless of values. This 150 * simply changes the address the host has to request on its 151 * side of the LPC bus. This cannot impact the hosts own 152 * memory space by surprise as LPC specific accessors are 153 * required. The only strange thing that could be done is 154 * setting the lower 16 bits but the shift takes care of that. 155 */ 156 157 rc = regmap_write(lpc_ctrl->regmap, HICR7, 158 (addr | (map.addr >> 16))); 159 if (rc) 160 return rc; 161 162 rc = regmap_write(lpc_ctrl->regmap, HICR8, 163 (~(map.size - 1)) | ((map.size >> 16) - 1)); 164 if (rc) 165 return rc; 166 167 /* 168 * Enable LPC FHW cycles. This is required for the host to 169 * access the regions specified. 170 */ 171 return regmap_update_bits(lpc_ctrl->regmap, HICR5, 172 HICR5_ENFWH | HICR5_ENL2H, 173 HICR5_ENFWH | HICR5_ENL2H); 174 } 175 176 return -EINVAL; 177 } 178 179 static const struct file_operations aspeed_lpc_ctrl_fops = { 180 .owner = THIS_MODULE, 181 .mmap = aspeed_lpc_ctrl_mmap, 182 .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, 183 }; 184 185 static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) 186 { 187 struct aspeed_lpc_ctrl *lpc_ctrl; 188 struct device_node *node; 189 struct resource resm; 190 struct device *dev; 191 int rc; 192 193 dev = &pdev->dev; 194 195 lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); 196 if (!lpc_ctrl) 197 return -ENOMEM; 198 199 node = of_parse_phandle(dev->of_node, "flash", 0); 200 if (!node) { 201 dev_err(dev, "Didn't find host pnor flash node\n"); 202 return -ENODEV; 203 } 204 205 rc = of_address_to_resource(node, 1, &resm); 206 of_node_put(node); 207 if (rc) { 208 dev_err(dev, "Couldn't address to resource for flash\n"); 209 return rc; 210 } 211 212 lpc_ctrl->pnor_size = resource_size(&resm); 213 lpc_ctrl->pnor_base = resm.start; 214 215 dev_set_drvdata(&pdev->dev, lpc_ctrl); 216 217 node = of_parse_phandle(dev->of_node, "memory-region", 0); 218 if (!node) { 219 dev_err(dev, "Didn't find reserved memory\n"); 220 return -EINVAL; 221 } 222 223 rc = of_address_to_resource(node, 0, &resm); 224 of_node_put(node); 225 if (rc) { 226 dev_err(dev, "Couldn't address to resource for reserved memory\n"); 227 return -ENOMEM; 228 } 229 230 lpc_ctrl->mem_size = resource_size(&resm); 231 lpc_ctrl->mem_base = resm.start; 232 233 lpc_ctrl->regmap = syscon_node_to_regmap( 234 pdev->dev.parent->of_node); 235 if (IS_ERR(lpc_ctrl->regmap)) { 236 dev_err(dev, "Couldn't get regmap\n"); 237 return -ENODEV; 238 } 239 240 lpc_ctrl->clk = devm_clk_get(dev, NULL); 241 if (IS_ERR(lpc_ctrl->clk)) { 242 dev_err(dev, "couldn't get clock\n"); 243 return PTR_ERR(lpc_ctrl->clk); 244 } 245 rc = clk_prepare_enable(lpc_ctrl->clk); 246 if (rc) { 247 dev_err(dev, "couldn't enable clock\n"); 248 return rc; 249 } 250 251 lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; 252 lpc_ctrl->miscdev.name = DEVICE_NAME; 253 lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; 254 lpc_ctrl->miscdev.parent = dev; 255 rc = misc_register(&lpc_ctrl->miscdev); 256 if (rc) { 257 dev_err(dev, "Unable to register device\n"); 258 goto err; 259 } 260 261 dev_info(dev, "Loaded at %pr\n", &resm); 262 263 return 0; 264 265 err: 266 clk_disable_unprepare(lpc_ctrl->clk); 267 return rc; 268 } 269 270 static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) 271 { 272 struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); 273 274 misc_deregister(&lpc_ctrl->miscdev); 275 clk_disable_unprepare(lpc_ctrl->clk); 276 277 return 0; 278 } 279 280 static const struct of_device_id aspeed_lpc_ctrl_match[] = { 281 { .compatible = "aspeed,ast2400-lpc-ctrl" }, 282 { .compatible = "aspeed,ast2500-lpc-ctrl" }, 283 { }, 284 }; 285 286 static struct platform_driver aspeed_lpc_ctrl_driver = { 287 .driver = { 288 .name = DEVICE_NAME, 289 .of_match_table = aspeed_lpc_ctrl_match, 290 }, 291 .probe = aspeed_lpc_ctrl_probe, 292 .remove = aspeed_lpc_ctrl_remove, 293 }; 294 295 module_platform_driver(aspeed_lpc_ctrl_driver); 296 297 MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); 298 MODULE_LICENSE("GPL"); 299 MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>"); 300 MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings"); 301