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 struct device *dev = file->private_data; 72 void __user *p = (void __user *)param; 73 struct aspeed_lpc_ctrl_mapping map; 74 u32 addr; 75 u32 size; 76 long rc; 77 78 if (copy_from_user(&map, p, sizeof(map))) 79 return -EFAULT; 80 81 if (map.flags != 0) 82 return -EINVAL; 83 84 switch (cmd) { 85 case ASPEED_LPC_CTRL_IOCTL_GET_SIZE: 86 /* The flash windows don't report their size */ 87 if (map.window_type != ASPEED_LPC_CTRL_WINDOW_MEMORY) 88 return -EINVAL; 89 90 /* Support more than one window id in the future */ 91 if (map.window_id != 0) 92 return -EINVAL; 93 94 /* If memory-region is not described in device tree */ 95 if (!lpc_ctrl->mem_size) { 96 dev_dbg(dev, "Didn't find reserved memory\n"); 97 return -ENXIO; 98 } 99 100 map.size = lpc_ctrl->mem_size; 101 102 return copy_to_user(p, &map, sizeof(map)) ? -EFAULT : 0; 103 case ASPEED_LPC_CTRL_IOCTL_MAP: 104 105 /* 106 * The top half of HICR7 is the MSB of the BMC address of the 107 * mapping. 108 * The bottom half of HICR7 is the MSB of the HOST LPC 109 * firmware space address of the mapping. 110 * 111 * The 1 bits in the top of half of HICR8 represent the bits 112 * (in the requested address) that should be ignored and 113 * replaced with those from the top half of HICR7. 114 * The 1 bits in the bottom half of HICR8 represent the bits 115 * (in the requested address) that should be kept and pass 116 * into the BMC address space. 117 */ 118 119 /* 120 * It doesn't make sense to talk about a size or offset with 121 * low 16 bits set. Both HICR7 and HICR8 talk about the top 16 122 * bits of addresses and sizes. 123 */ 124 125 if ((map.size & 0x0000ffff) || (map.offset & 0x0000ffff)) 126 return -EINVAL; 127 128 /* 129 * Because of the way the masks work in HICR8 offset has to 130 * be a multiple of size. 131 */ 132 if (map.offset & (map.size - 1)) 133 return -EINVAL; 134 135 if (map.window_type == ASPEED_LPC_CTRL_WINDOW_FLASH) { 136 if (!lpc_ctrl->pnor_size) { 137 dev_dbg(dev, "Didn't find host pnor flash\n"); 138 return -ENXIO; 139 } 140 addr = lpc_ctrl->pnor_base; 141 size = lpc_ctrl->pnor_size; 142 } else if (map.window_type == ASPEED_LPC_CTRL_WINDOW_MEMORY) { 143 /* If memory-region is not described in device tree */ 144 if (!lpc_ctrl->mem_size) { 145 dev_dbg(dev, "Didn't find reserved memory\n"); 146 return -ENXIO; 147 } 148 addr = lpc_ctrl->mem_base; 149 size = lpc_ctrl->mem_size; 150 } else { 151 return -EINVAL; 152 } 153 154 /* Check overflow first! */ 155 if (map.offset + map.size < map.offset || 156 map.offset + map.size > size) 157 return -EINVAL; 158 159 if (map.size == 0 || map.size > size) 160 return -EINVAL; 161 162 addr += map.offset; 163 164 /* 165 * addr (host lpc address) is safe regardless of values. This 166 * simply changes the address the host has to request on its 167 * side of the LPC bus. This cannot impact the hosts own 168 * memory space by surprise as LPC specific accessors are 169 * required. The only strange thing that could be done is 170 * setting the lower 16 bits but the shift takes care of that. 171 */ 172 173 rc = regmap_write(lpc_ctrl->regmap, HICR7, 174 (addr | (map.addr >> 16))); 175 if (rc) 176 return rc; 177 178 rc = regmap_write(lpc_ctrl->regmap, HICR8, 179 (~(map.size - 1)) | ((map.size >> 16) - 1)); 180 if (rc) 181 return rc; 182 183 /* 184 * Enable LPC FHW cycles. This is required for the host to 185 * access the regions specified. 186 */ 187 return regmap_update_bits(lpc_ctrl->regmap, HICR5, 188 HICR5_ENFWH | HICR5_ENL2H, 189 HICR5_ENFWH | HICR5_ENL2H); 190 } 191 192 return -EINVAL; 193 } 194 195 static const struct file_operations aspeed_lpc_ctrl_fops = { 196 .owner = THIS_MODULE, 197 .mmap = aspeed_lpc_ctrl_mmap, 198 .unlocked_ioctl = aspeed_lpc_ctrl_ioctl, 199 }; 200 201 static int aspeed_lpc_ctrl_probe(struct platform_device *pdev) 202 { 203 struct aspeed_lpc_ctrl *lpc_ctrl; 204 struct device_node *node; 205 struct resource resm; 206 struct device *dev; 207 int rc; 208 209 dev = &pdev->dev; 210 211 lpc_ctrl = devm_kzalloc(dev, sizeof(*lpc_ctrl), GFP_KERNEL); 212 if (!lpc_ctrl) 213 return -ENOMEM; 214 215 /* If flash is described in device tree then store */ 216 node = of_parse_phandle(dev->of_node, "flash", 0); 217 if (!node) { 218 dev_dbg(dev, "Didn't find host pnor flash node\n"); 219 } else { 220 rc = of_address_to_resource(node, 1, &resm); 221 of_node_put(node); 222 if (rc) { 223 dev_err(dev, "Couldn't address to resource for flash\n"); 224 return rc; 225 } 226 } 227 228 lpc_ctrl->pnor_size = resource_size(&resm); 229 lpc_ctrl->pnor_base = resm.start; 230 231 dev_set_drvdata(&pdev->dev, lpc_ctrl); 232 233 /* If memory-region is described in device tree then store */ 234 node = of_parse_phandle(dev->of_node, "memory-region", 0); 235 if (!node) { 236 dev_dbg(dev, "Didn't find reserved memory\n"); 237 } else { 238 rc = of_address_to_resource(node, 0, &resm); 239 of_node_put(node); 240 if (rc) { 241 dev_err(dev, "Couldn't address to resource for reserved memory\n"); 242 return -ENXIO; 243 } 244 245 lpc_ctrl->mem_size = resource_size(&resm); 246 lpc_ctrl->mem_base = resm.start; 247 } 248 249 lpc_ctrl->regmap = syscon_node_to_regmap( 250 pdev->dev.parent->of_node); 251 if (IS_ERR(lpc_ctrl->regmap)) { 252 dev_err(dev, "Couldn't get regmap\n"); 253 return -ENODEV; 254 } 255 256 lpc_ctrl->clk = devm_clk_get(dev, NULL); 257 if (IS_ERR(lpc_ctrl->clk)) { 258 dev_err(dev, "couldn't get clock\n"); 259 return PTR_ERR(lpc_ctrl->clk); 260 } 261 rc = clk_prepare_enable(lpc_ctrl->clk); 262 if (rc) { 263 dev_err(dev, "couldn't enable clock\n"); 264 return rc; 265 } 266 267 lpc_ctrl->miscdev.minor = MISC_DYNAMIC_MINOR; 268 lpc_ctrl->miscdev.name = DEVICE_NAME; 269 lpc_ctrl->miscdev.fops = &aspeed_lpc_ctrl_fops; 270 lpc_ctrl->miscdev.parent = dev; 271 rc = misc_register(&lpc_ctrl->miscdev); 272 if (rc) { 273 dev_err(dev, "Unable to register device\n"); 274 goto err; 275 } 276 277 return 0; 278 279 err: 280 clk_disable_unprepare(lpc_ctrl->clk); 281 return rc; 282 } 283 284 static int aspeed_lpc_ctrl_remove(struct platform_device *pdev) 285 { 286 struct aspeed_lpc_ctrl *lpc_ctrl = dev_get_drvdata(&pdev->dev); 287 288 misc_deregister(&lpc_ctrl->miscdev); 289 clk_disable_unprepare(lpc_ctrl->clk); 290 291 return 0; 292 } 293 294 static const struct of_device_id aspeed_lpc_ctrl_match[] = { 295 { .compatible = "aspeed,ast2400-lpc-ctrl" }, 296 { .compatible = "aspeed,ast2500-lpc-ctrl" }, 297 { }, 298 }; 299 300 static struct platform_driver aspeed_lpc_ctrl_driver = { 301 .driver = { 302 .name = DEVICE_NAME, 303 .of_match_table = aspeed_lpc_ctrl_match, 304 }, 305 .probe = aspeed_lpc_ctrl_probe, 306 .remove = aspeed_lpc_ctrl_remove, 307 }; 308 309 module_platform_driver(aspeed_lpc_ctrl_driver); 310 311 MODULE_DEVICE_TABLE(of, aspeed_lpc_ctrl_match); 312 MODULE_LICENSE("GPL"); 313 MODULE_AUTHOR("Cyril Bur <[email protected]>"); 314 MODULE_DESCRIPTION("Control for aspeed 2400/2500 LPC HOST to BMC mappings"); 315