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 static const char *ltq_probe_types[] __devinitconst = { "cmdlinepart", NULL }; 49 50 static map_word 51 ltq_read16(struct map_info *map, unsigned long adr) 52 { 53 unsigned long flags; 54 map_word temp; 55 56 if (map->map_priv_1 == LTQ_NOR_PROBING) 57 adr ^= 2; 58 spin_lock_irqsave(&ebu_lock, flags); 59 temp.x[0] = *(u16 *)(map->virt + adr); 60 spin_unlock_irqrestore(&ebu_lock, flags); 61 return temp; 62 } 63 64 static void 65 ltq_write16(struct map_info *map, map_word d, unsigned long adr) 66 { 67 unsigned long flags; 68 69 if (map->map_priv_1 == LTQ_NOR_PROBING) 70 adr ^= 2; 71 spin_lock_irqsave(&ebu_lock, flags); 72 *(u16 *)(map->virt + adr) = d.x[0]; 73 spin_unlock_irqrestore(&ebu_lock, flags); 74 } 75 76 /* 77 * The following 2 functions copy data between iomem and a cached memory 78 * section. As memcpy() makes use of pre-fetching we cannot use it here. 79 * The normal alternative of using memcpy_{to,from}io also makes use of 80 * memcpy() on MIPS so it is not applicable either. We are therefore stuck 81 * with having to use our own loop. 82 */ 83 static void 84 ltq_copy_from(struct map_info *map, void *to, 85 unsigned long from, ssize_t len) 86 { 87 unsigned char *f = (unsigned char *)map->virt + from; 88 unsigned char *t = (unsigned char *)to; 89 unsigned long flags; 90 91 spin_lock_irqsave(&ebu_lock, flags); 92 while (len--) 93 *t++ = *f++; 94 spin_unlock_irqrestore(&ebu_lock, flags); 95 } 96 97 static void 98 ltq_copy_to(struct map_info *map, unsigned long to, 99 const void *from, ssize_t len) 100 { 101 unsigned char *f = (unsigned char *)from; 102 unsigned char *t = (unsigned char *)map->virt + to; 103 unsigned long flags; 104 105 spin_lock_irqsave(&ebu_lock, flags); 106 while (len--) 107 *t++ = *f++; 108 spin_unlock_irqrestore(&ebu_lock, flags); 109 } 110 111 static int __init 112 ltq_mtd_probe(struct platform_device *pdev) 113 { 114 struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev); 115 struct ltq_mtd *ltq_mtd; 116 struct resource *res; 117 struct cfi_private *cfi; 118 int err; 119 120 ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL); 121 platform_set_drvdata(pdev, ltq_mtd); 122 123 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 124 if (!ltq_mtd->res) { 125 dev_err(&pdev->dev, "failed to get memory resource"); 126 err = -ENOENT; 127 goto err_out; 128 } 129 130 res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start, 131 resource_size(ltq_mtd->res), dev_name(&pdev->dev)); 132 if (!ltq_mtd->res) { 133 dev_err(&pdev->dev, "failed to request mem resource"); 134 err = -EBUSY; 135 goto err_out; 136 } 137 138 ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL); 139 ltq_mtd->map->phys = res->start; 140 ltq_mtd->map->size = resource_size(res); 141 ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev, 142 ltq_mtd->map->phys, ltq_mtd->map->size); 143 if (!ltq_mtd->map->virt) { 144 dev_err(&pdev->dev, "failed to ioremap!\n"); 145 err = -ENOMEM; 146 goto err_free; 147 } 148 149 ltq_mtd->map->name = ltq_map_name; 150 ltq_mtd->map->bankwidth = 2; 151 ltq_mtd->map->read = ltq_read16; 152 ltq_mtd->map->write = ltq_write16; 153 ltq_mtd->map->copy_from = ltq_copy_from; 154 ltq_mtd->map->copy_to = ltq_copy_to; 155 156 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING; 157 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map); 158 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL; 159 160 if (!ltq_mtd->mtd) { 161 dev_err(&pdev->dev, "probing failed\n"); 162 err = -ENXIO; 163 goto err_free; 164 } 165 166 ltq_mtd->mtd->owner = THIS_MODULE; 167 168 cfi = ltq_mtd->map->fldrv_priv; 169 cfi->addr_unlock1 ^= 1; 170 cfi->addr_unlock2 ^= 1; 171 172 err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, NULL, 173 ltq_mtd_data->parts, 174 ltq_mtd_data->nr_parts); 175 if (err) { 176 dev_err(&pdev->dev, "failed to add partitions\n"); 177 goto err_destroy; 178 } 179 180 return 0; 181 182 err_destroy: 183 map_destroy(ltq_mtd->mtd); 184 err_free: 185 kfree(ltq_mtd->map); 186 err_out: 187 kfree(ltq_mtd); 188 return err; 189 } 190 191 static int __devexit 192 ltq_mtd_remove(struct platform_device *pdev) 193 { 194 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev); 195 196 if (ltq_mtd) { 197 if (ltq_mtd->mtd) { 198 mtd_device_unregister(ltq_mtd->mtd); 199 map_destroy(ltq_mtd->mtd); 200 } 201 kfree(ltq_mtd->map); 202 kfree(ltq_mtd); 203 } 204 return 0; 205 } 206 207 static struct platform_driver ltq_mtd_driver = { 208 .remove = __devexit_p(ltq_mtd_remove), 209 .driver = { 210 .name = "ltq_nor", 211 .owner = THIS_MODULE, 212 }, 213 }; 214 215 static int __init 216 init_ltq_mtd(void) 217 { 218 int ret = platform_driver_probe(<q_mtd_driver, ltq_mtd_probe); 219 220 if (ret) 221 pr_err("ltq_nor: error registering platform driver"); 222 return ret; 223 } 224 225 static void __exit 226 exit_ltq_mtd(void) 227 { 228 platform_driver_unregister(<q_mtd_driver); 229 } 230 231 module_init(init_ltq_mtd); 232 module_exit(exit_ltq_mtd); 233 234 MODULE_LICENSE("GPL"); 235 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); 236 MODULE_DESCRIPTION("Lantiq SoC NOR"); 237