1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2017 IBM Corporation 4 */ 5 6 #include <linux/clk.h> 7 #include <linux/log2.h> 8 #include <linux/mfd/syscon.h> 9 #include <linux/miscdevice.h> 10 #include <linux/mm.h> 11 #include <linux/module.h> 12 #include <linux/of_address.h> 13 #include <linux/platform_device.h> 14 #include <linux/poll.h> 15 #include <linux/regmap.h> 16 17 #include <linux/aspeed-lpc-ctrl.h> 18 19 #define DEVICE_NAME "aspeed-lpc-ctrl" 20 21 #define HICR5 0x80 22 #define HICR5_ENL2H BIT(8) 23 #define HICR5_ENFWH BIT(10) 24 25 #define HICR6 0x84 26 #define SW_FWH2AHB BIT(17) 27 28 #define HICR7 0x88 29 #define HICR8 0x8c 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 bool fwh2ahb; 40 }; 41 42 static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) 43 { 44 return container_of(file->private_data, struct aspeed_lpc_ctrl, 45 miscdev); 46 } 47 48 static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) 49 { 50 struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); 51 unsigned long vsize = vma->vm_end - vma->vm_start; 52 pgprot_t prot = vma->vm_page_prot; 53 54 if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size) 55 return -EINVAL; 56 57 /* ast2400/2500 AHB accesses are not cache coherent */ 58 prot = pgprot_noncached(prot); 59 60 if (remap_pfn_range(vma, vma->vm_start, 61 (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, 62 vsize, prot)) 63 return -EAGAIN; 64 65 return 0; 66 } 67 68 static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, 69 unsigned long param) 70 { 71 struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); 72 struct device *dev = file->private_data; 73 void __user *p = (void __user *)param; 74 struct aspeed_lpc_ctrl_mapping map; 75 u32 addr; 76 u32 size; 77 long rc; 78 79 if (copy_from_user(&map, p, sizeof(map))) 80 return -EFAULT; 81 82 if (map.flags != 0) 83 return -EINVAL; 84 85 switch (cmd) { 86 case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: 87 /* The flash windows don't report their size */ 88 if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) 89 return -EINVAL; 90 91 /* Support more than one window id in the future */ 92 if (map.window_id != 0) 93 return -EINVAL; 94 95 /* If memory-region is not described in device tree */ 96 if (!lpc_ctrl->mem_size) { 97 dev_dbg(dev, "Didn't find reserved memory\n"); 98 return -ENXIO; 99 } 100 101 map.size = lpc_ctrl->mem_size; 102 103 return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; 104 case ASPEED_LPC_CTRL_IOCTL_MAP: 105 106 /* 107 * The top half of HICR7 is the MSB of the BMC address of the 108 * mapping. 109 * The bottom half of HICR7 is the MSB of the HOST LPC 110 * firmware space address of the mapping. 111 * 112 * The 1 bits in the top of half of HICR8 represent the bits 113 * (in the requested address) that should be ignored and 114 * replaced with those from the top half of HICR7. 115 * The 1 bits in the bottom half of HICR8 represent the bits 116 * (in the requested address) that should be kept and pass 117 * into the BMC address space. 118 */ 119 120 /* 121 * It doesn't make sense to talk about a size or offset with 122 * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 123 * bits of addresses and sizes. 124 */ 125 126 if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) 127 return -EINVAL; 128 129 /* 130 * Because of the way the masks work in HICR8 offset has to 131 * be a multiple of size. 132 */ 133 if (map.offset & (map.size - 1)) 134 return -EINVAL; 135 136 if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { 137 if (!lpc_ctrl->pnor_size) { 138 dev_dbg(dev, "Didn't find host pnor flash\n"); 139 return -ENXIO; 140 } 141 addr = lpc_ctrl->pnor_base; 142 size = lpc_ctrl->pnor_size; 143 } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { 144 /* If memory-region is not described in device tree */ 145 if (!lpc_ctrl->mem_size) { 146 dev_dbg(dev, "Didn't find reserved memory\n"); 147 return -ENXIO; 148 } 149 addr = lpc_ctrl->mem_base; 150 size = lpc_ctrl->mem_size; 151 } else { 152 return -EINVAL; 153 } 154 155 /* Check overflow first! */ 156 if (map.offset + map.size < map.offset || 157 map.offset + map.size > size) 158 return -EINVAL; 159 160 if (map.size == 0 || map.size > size) 161 return -EINVAL; 162 163 addr += map.offset; 164 165 /* 166 * addr (host lpc address) is safe regardless of values. This 167 * simply changes the address the host has to request on its 168 * side of the LPC bus. This cannot impact the hosts own 169 * memory space by surprise as LPC specific accessors are 170 * required. The only strange thing that could be done is 171 * setting the lower 16 bits but the shift takes care of that. 172 */ 173 174 rc = regmap_write(lpc_ctrl->regmap, HICR7, 175 (addr | (map.addr >> 16))); 176 if (rc) 177 return rc; 178 179 rc = regmap_write(lpc_ctrl->regmap, HICR8, 180 (~(map.size - 1)) | ((map.size >> 16) - 1)); 181 if (rc) 182 return rc; 183 184 /* 185 * Switch to FWH2AHB mode, AST2600 only. 186 * 187 * The other bits in this register are interrupt status bits 188 * that are cleared by writing 1. As we don't want to clear 189 * them, set only the bit of interest. 190 */ 191 if (lpc_ctrl->fwh2ahb) 192 regmap_write(lpc_ctrl->regmap, HICR6, SW_FWH2AHB); 193 194 /* 195 * Enable LPC FHW cycles. This is required for the host to 196 * access the regions specified. 197 */ 198 return regmap_update_bits(lpc_ctrl->regmap, HICR5, 199 HICR5_ENFWH | HICR5_ENL2H, 200 HICR5_ENFWH | HICR5_ENL2H); 201 } 202 203 return -EINVAL; 204 } 205 206 static const struct file_operations aspeed_lpc_ctrl_fops = { 207 .owner = THIS_MODULE, 208 .mmap = aspeed_lpc_ctrl_mmap, 209 .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, 210 }; 211 212 static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) 213 { 214 struct aspeed_lpc_ctrl *lpc_ctrl; 215 struct device_node *node; 216 struct resource resm; 217 struct device *dev; 218 struct device_node *np; 219 int rc; 220 221 dev = &pdev->dev; 222 223 lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); 224 if (!lpc_ctrl) 225 return -ENOMEM; 226 227 /* If flash is described in device tree then store */ 228 node = of_parse_phandle(dev->of_node, "flash", 0); 229 if (!node) { 230 dev_dbg(dev, "Didn't find host pnor flash node\n"); 231 } else { 232 rc = of_address_to_resource(node, 1, &resm); 233 of_node_put(node); 234 if (rc) { 235 dev_err(dev, "Couldn't address to resource for flash\n"); 236 return rc; 237 } 238 239 lpc_ctrl->pnor_size = resource_size(&resm); 240 lpc_ctrl->pnor_base = resm.start; 241 } 242 243 244 dev_set_drvdata(&pdev->dev, lpc_ctrl); 245 246 /* If memory-region is described in device tree then store */ 247 node = of_parse_phandle(dev->of_node, "memory-region", 0); 248 if (!node) { 249 dev_dbg(dev, "Didn't find reserved memory\n"); 250 } else { 251 rc = of_address_to_resource(node, 0, &resm); 252 of_node_put(node); 253 if (rc) { 254 dev_err(dev, "Couldn't address to resource for reserved memory\n"); 255 return -ENXIO; 256 } 257 258 lpc_ctrl->mem_size = resource_size(&resm); 259 lpc_ctrl->mem_base = resm.start; 260 261 if (!is_power_of_2(lpc_ctrl->mem_size)) { 262 dev_err(dev, "Reserved memory size must be a power of 2, got %u\n", 263 (unsigned int)lpc_ctrl->mem_size); 264 return -EINVAL; 265 } 266 267 if (!IS_ALIGNED(lpc_ctrl->mem_base, lpc_ctrl->mem_size)) { 268 dev_err(dev, "Reserved memory must be naturally aligned for size %u\n", 269 (unsigned int)lpc_ctrl->mem_size); 270 return -EINVAL; 271 } 272 } 273 274 np = pdev->dev.parent->of_node; 275 if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") && 276 !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") && 277 !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) { 278 dev_err(dev, "unsupported LPC device binding\n"); 279 return -ENODEV; 280 } 281 282 lpc_ctrl->regmap = syscon_node_to_regmap(np); 283 if (IS_ERR(lpc_ctrl->regmap)) { 284 dev_err(dev, "Couldn't get regmap\n"); 285 return -ENODEV; 286 } 287 288 lpc_ctrl->clk = devm_clk_get(dev, NULL); 289 if (IS_ERR(lpc_ctrl->clk)) { 290 dev_err(dev, "couldn't get clock\n"); 291 return PTR_ERR(lpc_ctrl->clk); 292 } 293 rc = clk_prepare_enable(lpc_ctrl->clk); 294 if (rc) { 295 dev_err(dev, "couldn't enable clock\n"); 296 return rc; 297 } 298 299 if (of_device_is_compatible(dev->of_node, "aspeed,ast2600-lpc-ctrl")) 300 lpc_ctrl->fwh2ahb = true; 301 302 lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; 303 lpc_ctrl->miscdev.name = DEVICE_NAME; 304 lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; 305 lpc_ctrl->miscdev.parent = dev; 306 rc = misc_register(&lpc_ctrl->miscdev); 307 if (rc) { 308 dev_err(dev, "Unable to register device\n"); 309 goto err; 310 } 311 312 return 0; 313 314 err: 315 clk_disable_unprepare(lpc_ctrl->clk); 316 return rc; 317 } 318 319 static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) 320 { 321 struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); 322 323 misc_deregister(&lpc_ctrl->miscdev); 324 clk_disable_unprepare(lpc_ctrl->clk); 325 326 return 0; 327 } 328 329 static const struct of_device_id aspeed_lpc_ctrl_match[] = { 330 { .compatible = "aspeed,ast2400-lpc-ctrl" }, 331 { .compatible = "aspeed,ast2500-lpc-ctrl" }, 332 { .compatible = "aspeed,ast2600-lpc-ctrl" }, 333 { }, 334 }; 335 336 static struct platform_driver aspeed_lpc_ctrl_driver = { 337 .driver = { 338 .name = DEVICE_NAME, 339 .of_match_table = aspeed_lpc_ctrl_match, 340 }, 341 .probe = aspeed_lpc_ctrl_probe, 342 .remove = aspeed_lpc_ctrl_remove, 343 }; 344 345 module_platform_driver(aspeed_lpc_ctrl_driver); 346 347 MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); 348 MODULE_LICENSE("GPL"); 349 MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>"); 350 MODULE_DESCRIPTION("Control for ASPEED LPC HOST to BMC mappings"); 351