1 /* 2 * This program is free software; you can redistribute it and/or modify it 3 * under the terms of the GNU General Public License version 2 as published 4 * by the Free Software Foundation. 5 * 6 * Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE 7 * Copyright (C) 2010 John Crispin <blogic@openwrt.org> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/io.h> 14 #include <linux/slab.h> 15 #include <linux/init.h> 16 #include <linux/mtd/mtd.h> 17 #include <linux/mtd/map.h> 18 #include <linux/mtd/partitions.h> 19 #include <linux/mtd/cfi.h> 20 #include <linux/platform_device.h> 21 #include <linux/mtd/physmap.h> 22 23 #include <lantiq_soc.h> 24 #include <lantiq_platform.h> 25 26 /* 27 * The NOR flash is connected to the same external bus unit (EBU) as PCI. 28 * To make PCI work we need to enable the endianness swapping for the address 29 * written to the EBU. This endianness swapping works for PCI correctly but 30 * fails for attached NOR devices. To workaround this we need to use a complex 31 * map. The workaround involves swapping all addresses whilst probing the chip. 32 * Once probing is complete we stop swapping the addresses but swizzle the 33 * unlock addresses to ensure that access to the NOR device works correctly. 34 */ 35 36 enum { 37 LTQ_NOR_PROBING, 38 LTQ_NOR_NORMAL 39 }; 40 41 struct ltq_mtd { 42 struct resource *res; 43 struct mtd_info *mtd; 44 struct map_info *map; 45 }; 46 47 static char ltq_map_name[] = "ltq_nor"; 48 49 static map_word 50 ltq_read16(struct map_info *map, unsigned long adr) 51 { 52 unsigned long flags; 53 map_word temp; 54 55 if (map->map_priv_1 == LTQ_NOR_PROBING) 56 adr ^= 2; 57 spin_lock_irqsave(&ebu_lock, flags); 58 temp.x[0] = *(u16 *)(map->virt + adr); 59 spin_unlock_irqrestore(&ebu_lock, flags); 60 return temp; 61 } 62 63 static void 64 ltq_write16(struct map_info *map, map_word d, unsigned long adr) 65 { 66 unsigned long flags; 67 68 if (map->map_priv_1 == LTQ_NOR_PROBING) 69 adr ^= 2; 70 spin_lock_irqsave(&ebu_lock, flags); 71 *(u16 *)(map->virt + adr) = d.x[0]; 72 spin_unlock_irqrestore(&ebu_lock, flags); 73 } 74 75 /* 76 * The following 2 functions copy data between iomem and a cached memory 77 * section. As memcpy() makes use of pre-fetching we cannot use it here. 78 * The normal alternative of using memcpy_{to,from}io also makes use of 79 * memcpy() on MIPS so it is not applicable either. We are therefore stuck 80 * with having to use our own loop. 81 */ 82 static void 83 ltq_copy_from(struct map_info *map, void *to, 84 unsigned long from, ssize_t len) 85 { 86 unsigned char *f = (unsigned char *)map->virt + from; 87 unsigned char *t = (unsigned char *)to; 88 unsigned long flags; 89 90 spin_lock_irqsave(&ebu_lock, flags); 91 while (len--) 92 *t++ = *f++; 93 spin_unlock_irqrestore(&ebu_lock, flags); 94 } 95 96 static void 97 ltq_copy_to(struct map_info *map, unsigned long to, 98 const void *from, ssize_t len) 99 { 100 unsigned char *f = (unsigned char *)from; 101 unsigned char *t = (unsigned char *)map->virt + to; 102 unsigned long flags; 103 104 spin_lock_irqsave(&ebu_lock, flags); 105 while (len--) 106 *t++ = *f++; 107 spin_unlock_irqrestore(&ebu_lock, flags); 108 } 109 110 static const char const *part_probe_types[] = { "cmdlinepart", NULL }; 111 112 static int __init 113 ltq_mtd_probe(struct platform_device *pdev) 114 { 115 struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev); 116 struct ltq_mtd *ltq_mtd; 117 struct mtd_partition *parts; 118 struct resource *res; 119 int nr_parts = 0; 120 struct cfi_private *cfi; 121 int err; 122 123 ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL); 124 platform_set_drvdata(pdev, ltq_mtd); 125 126 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 127 if (!ltq_mtd->res) { 128 dev_err(&pdev->dev, "failed to get memory resource"); 129 err = -ENOENT; 130 goto err_out; 131 } 132 133 res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start, 134 resource_size(ltq_mtd->res), dev_name(&pdev->dev)); 135 if (!ltq_mtd->res) { 136 dev_err(&pdev->dev, "failed to request mem resource"); 137 err = -EBUSY; 138 goto err_out; 139 } 140 141 ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL); 142 ltq_mtd->map->phys = res->start; 143 ltq_mtd->map->size = resource_size(res); 144 ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev, 145 ltq_mtd->map->phys, ltq_mtd->map->size); 146 if (!ltq_mtd->map->virt) { 147 dev_err(&pdev->dev, "failed to ioremap!\n"); 148 err = -ENOMEM; 149 goto err_free; 150 } 151 152 ltq_mtd->map->name = ltq_map_name; 153 ltq_mtd->map->bankwidth = 2; 154 ltq_mtd->map->read = ltq_read16; 155 ltq_mtd->map->write = ltq_write16; 156 ltq_mtd->map->copy_from = ltq_copy_from; 157 ltq_mtd->map->copy_to = ltq_copy_to; 158 159 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING; 160 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map); 161 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL; 162 163 if (!ltq_mtd->mtd) { 164 dev_err(&pdev->dev, "probing failed\n"); 165 err = -ENXIO; 166 goto err_unmap; 167 } 168 169 ltq_mtd->mtd->owner = THIS_MODULE; 170 171 cfi = ltq_mtd->map->fldrv_priv; 172 cfi->addr_unlock1 ^= 1; 173 cfi->addr_unlock2 ^= 1; 174 175 nr_parts = parse_mtd_partitions(ltq_mtd->mtd, 176 part_probe_types, &parts, 0); 177 if (nr_parts > 0) { 178 dev_info(&pdev->dev, 179 "using %d partitions from cmdline", nr_parts); 180 } else { 181 nr_parts = ltq_mtd_data->nr_parts; 182 parts = ltq_mtd_data->parts; 183 } 184 185 err = add_mtd_partitions(ltq_mtd->mtd, parts, nr_parts); 186 if (err) { 187 dev_err(&pdev->dev, "failed to add partitions\n"); 188 goto err_destroy; 189 } 190 191 return 0; 192 193 err_destroy: 194 map_destroy(ltq_mtd->mtd); 195 err_unmap: 196 iounmap(ltq_mtd->map->virt); 197 err_free: 198 kfree(ltq_mtd->map); 199 err_out: 200 kfree(ltq_mtd); 201 return err; 202 } 203 204 static int __devexit 205 ltq_mtd_remove(struct platform_device *pdev) 206 { 207 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev); 208 209 if (ltq_mtd) { 210 if (ltq_mtd->mtd) { 211 del_mtd_partitions(ltq_mtd->mtd); 212 map_destroy(ltq_mtd->mtd); 213 } 214 if (ltq_mtd->map->virt) 215 iounmap(ltq_mtd->map->virt); 216 kfree(ltq_mtd->map); 217 kfree(ltq_mtd); 218 } 219 return 0; 220 } 221 222 static struct platform_driver ltq_mtd_driver = { 223 .remove = __devexit_p(ltq_mtd_remove), 224 .driver = { 225 .name = "ltq_nor", 226 .owner = THIS_MODULE, 227 }, 228 }; 229 230 static int __init 231 init_ltq_mtd(void) 232 { 233 int ret = platform_driver_probe(<q_mtd_driver, ltq_mtd_probe); 234 235 if (ret) 236 pr_err("ltq_nor: error registering platform driver"); 237 return ret; 238 } 239 240 static void __exit 241 exit_ltq_mtd(void) 242 { 243 platform_driver_unregister(<q_mtd_driver); 244 } 245 246 module_init(init_ltq_mtd); 247 module_exit(exit_ltq_mtd); 248 249 MODULE_LICENSE("GPL"); 250 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); 251 MODULE_DESCRIPTION("Lantiq SoC NOR"); 252