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/mfd/syscon.h> 8 #include <linux/miscdevice.h> 9 #include <linux/mm.h> 10 #include <linux/module.h> 11 #include <linux/of_address.h> 12 #include <linux/platform_device.h> 13 #include <linux/poll.h> 14 #include <linux/regmap.h> 15 16 #include <linux/aspeed-lpc-ctrl.h> 17 18 #define DEVICE_NAME "aspeed-lpc-ctrl" 19 20 #define HICR5 0x0 21 #define HICR5_ENL2H BIT(8) 22 #define HICR5_ENFWH BIT(10) 23 24 #define HICR7 0x8 25 #define HICR8 0xc 26 27 struct aspeed_lpc_ctrl { 28 struct miscdevice miscdev; 29 struct regmap *regmap; 30 struct clk *clk; 31 phys_addr_t mem_base; 32 resource_size_t mem_size; 33 u32 pnor_size; 34 u32 pnor_base; 35 }; 36 37 static struct aspeed_lpc_ctrl *file_aspeed_lpc_ctrl(struct file *file) 38 { 39 return container_of(file->private_data, struct aspeed_lpc_ctrl, 40 miscdev); 41 } 42 43 static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) 44 { 45 struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); 46 unsigned long vsize = vma->vm_end - vma->vm_start; 47 pgprot_t prot = vma->vm_page_prot; 48 49 if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size) 50 return -EINVAL; 51 52 /* ast2400/2500 AHB accesses are not cache coherent */ 53 prot = pgprot_noncached(prot); 54 55 if (remap_pfn_range(vma, vma->vm_start, 56 (lpc_ctrl->mem_base >> PAGE_SHIFT) + vma->vm_pgoff, 57 vsize, prot)) 58 return -EAGAIN; 59 60 return 0; 61 } 62 63 static long aspeed_lpc_ctrl_ioctl(struct file *file, unsigned int cmd, 64 unsigned long param) 65 { 66 struct aspeed_lpc_ctrl *lpc_ctrl = file_aspeed_lpc_ctrl(file); 67 struct device *dev = file->private_data; 68 void __user *p = (void __user *)param; 69 struct aspeed_lpc_ctrl_mapping map; 70 u32 addr; 71 u32 size; 72 long rc; 73 74 if (copy_from_user(&map, p, sizeof(map))) 75 return -EFAULT; 76 77 if (map.flags != 0) 78 return -EINVAL; 79 80 switch (cmd) { 81 case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: 82 /* The flash windows don't report their size */ 83 if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) 84 return -EINVAL; 85 86 /* Support more than one window id in the future */ 87 if (map.window_id != 0) 88 return -EINVAL; 89 90 /* If memory-region is not described in device tree */ 91 if (!lpc_ctrl->mem_size) { 92 dev_dbg(dev, "Didn't find reserved memory\n"); 93 return -ENXIO; 94 } 95 96 map.size = lpc_ctrl->mem_size; 97 98 return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; 99 case ASPEED_LPC_CTRL_IOCTL_MAP: 100 101 /* 102 * The top half of HICR7 is the MSB of the BMC address of the 103 * mapping. 104 * The bottom half of HICR7 is the MSB of the HOST LPC 105 * firmware space address of the mapping. 106 * 107 * The 1 bits in the top of half of HICR8 represent the bits 108 * (in the requested address) that should be ignored and 109 * replaced with those from the top half of HICR7. 110 * The 1 bits in the bottom half of HICR8 represent the bits 111 * (in the requested address) that should be kept and pass 112 * into the BMC address space. 113 */ 114 115 /* 116 * It doesn't make sense to talk about a size or offset with 117 * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 118 * bits of addresses and sizes. 119 */ 120 121 if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) 122 return -EINVAL; 123 124 /* 125 * Because of the way the masks work in HICR8 offset has to 126 * be a multiple of size. 127 */ 128 if (map.offset & (map.size - 1)) 129 return -EINVAL; 130 131 if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { 132 if (!lpc_ctrl->pnor_size) { 133 dev_dbg(dev, "Didn't find host pnor flash\n"); 134 return -ENXIO; 135 } 136 addr = lpc_ctrl->pnor_base; 137 size = lpc_ctrl->pnor_size; 138 } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { 139 /* If memory-region is not described in device tree */ 140 if (!lpc_ctrl->mem_size) { 141 dev_dbg(dev, "Didn't find reserved memory\n"); 142 return -ENXIO; 143 } 144 addr = lpc_ctrl->mem_base; 145 size = lpc_ctrl->mem_size; 146 } else { 147 return -EINVAL; 148 } 149 150 /* Check overflow first! */ 151 if (map.offset + map.size < map.offset || 152 map.offset + map.size > size) 153 return -EINVAL; 154 155 if (map.size == 0 || map.size > size) 156 return -EINVAL; 157 158 addr += map.offset; 159 160 /* 161 * addr (host lpc address) is safe regardless of values. This 162 * simply changes the address the host has to request on its 163 * side of the LPC bus. This cannot impact the hosts own 164 * memory space by surprise as LPC specific accessors are 165 * required. The only strange thing that could be done is 166 * setting the lower 16 bits but the shift takes care of that. 167 */ 168 169 rc = regmap_write(lpc_ctrl->regmap, HICR7, 170 (addr | (map.addr >> 16))); 171 if (rc) 172 return rc; 173 174 rc = regmap_write(lpc_ctrl->regmap, HICR8, 175 (~(map.size - 1)) | ((map.size >> 16) - 1)); 176 if (rc) 177 return rc; 178 179 /* 180 * Enable LPC FHW cycles. This is required for the host to 181 * access the regions specified. 182 */ 183 return regmap_update_bits(lpc_ctrl->regmap, HICR5, 184 HICR5_ENFWH | HICR5_ENL2H, 185 HICR5_ENFWH | HICR5_ENL2H); 186 } 187 188 return -EINVAL; 189 } 190 191 static const struct file_operations aspeed_lpc_ctrl_fops = { 192 .owner = THIS_MODULE, 193 .mmap = aspeed_lpc_ctrl_mmap, 194 .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, 195 }; 196 197 static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) 198 { 199 struct aspeed_lpc_ctrl *lpc_ctrl; 200 struct device_node *node; 201 struct resource resm; 202 struct device *dev; 203 int rc; 204 205 dev = &pdev->dev; 206 207 lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); 208 if (!lpc_ctrl) 209 return -ENOMEM; 210 211 /* If flash is described in device tree then store */ 212 node = of_parse_phandle(dev->of_node, "flash", 0); 213 if (!node) { 214 dev_dbg(dev, "Didn't find host pnor flash node\n"); 215 } else { 216 rc = of_address_to_resource(node, 1, &resm); 217 of_node_put(node); 218 if (rc) { 219 dev_err(dev, "Couldn't address to resource for flash\n"); 220 return rc; 221 } 222 223 lpc_ctrl->pnor_size = resource_size(&resm); 224 lpc_ctrl->pnor_base = resm.start; 225 } 226 227 228 dev_set_drvdata(&pdev->dev, lpc_ctrl); 229 230 /* If memory-region is described in device tree then store */ 231 node = of_parse_phandle(dev->of_node, "memory-region", 0); 232 if (!node) { 233 dev_dbg(dev, "Didn't find reserved memory\n"); 234 } else { 235 rc = of_address_to_resource(node, 0, &resm); 236 of_node_put(node); 237 if (rc) { 238 dev_err(dev, "Couldn't address to resource for reserved memory\n"); 239 return -ENXIO; 240 } 241 242 lpc_ctrl->mem_size = resource_size(&resm); 243 lpc_ctrl->mem_base = resm.start; 244 } 245 246 lpc_ctrl->regmap = syscon_node_to_regmap( 247 pdev->dev.parent->of_node); 248 if (IS_ERR(lpc_ctrl->regmap)) { 249 dev_err(dev, "Couldn't get regmap\n"); 250 return -ENODEV; 251 } 252 253 lpc_ctrl->clk = devm_clk_get(dev, NULL); 254 if (IS_ERR(lpc_ctrl->clk)) { 255 dev_err(dev, "couldn't get clock\n"); 256 return PTR_ERR(lpc_ctrl->clk); 257 } 258 rc = clk_prepare_enable(lpc_ctrl->clk); 259 if (rc) { 260 dev_err(dev, "couldn't enable clock\n"); 261 return rc; 262 } 263 264 lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; 265 lpc_ctrl->miscdev.name = DEVICE_NAME; 266 lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; 267 lpc_ctrl->miscdev.parent = dev; 268 rc = misc_register(&lpc_ctrl->miscdev); 269 if (rc) { 270 dev_err(dev, "Unable to register device\n"); 271 goto err; 272 } 273 274 return 0; 275 276 err: 277 clk_disable_unprepare(lpc_ctrl->clk); 278 return rc; 279 } 280 281 static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) 282 { 283 struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); 284 285 misc_deregister(&lpc_ctrl->miscdev); 286 clk_disable_unprepare(lpc_ctrl->clk); 287 288 return 0; 289 } 290 291 static const struct of_device_id aspeed_lpc_ctrl_match[] = { 292 { .compatible = "aspeed,ast2400-lpc-ctrl" }, 293 { .compatible = "aspeed,ast2500-lpc-ctrl" }, 294 { }, 295 }; 296 297 static struct platform_driver aspeed_lpc_ctrl_driver = { 298 .driver = { 299 .name = DEVICE_NAME, 300 .of_match_table = aspeed_lpc_ctrl_match, 301 }, 302 .probe = aspeed_lpc_ctrl_probe, 303 .remove = aspeed_lpc_ctrl_remove, 304 }; 305 306 module_platform_driver(aspeed_lpc_ctrl_driver); 307 308 MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); 309 MODULE_LICENSE("GPL"); 310 MODULE_AUTHOR("Cyril Bur <cyrilbur@gmail.com>"); 311 MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings"); 312