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/err.h> 11 #include <linux/module.h> 12 #include <linux/types.h> 13 #include <linux/kernel.h> 14 #include <linux/io.h> 15 #include <linux/slab.h> 16 #include <linux/init.h> 17 #include <linux/mtd/mtd.h> 18 #include <linux/mtd/map.h> 19 #include <linux/mtd/partitions.h> 20 #include <linux/mtd/cfi.h> 21 #include <linux/platform_device.h> 22 #include <linux/mtd/physmap.h> 23 #include <linux/of.h> 24 25 #include <lantiq_soc.h> 26 27 /* 28 * The NOR flash is connected to the same external bus unit (EBU) as PCI. 29 * To make PCI work we need to enable the endianness swapping for the address 30 * written to the EBU. This endianness swapping works for PCI correctly but 31 * fails for attached NOR devices. To workaround this we need to use a complex 32 * map. The workaround involves swapping all addresses whilst probing the chip. 33 * Once probing is complete we stop swapping the addresses but swizzle the 34 * unlock addresses to ensure that access to the NOR device works correctly. 35 */ 36 37 enum { 38 LTQ_NOR_PROBING, 39 LTQ_NOR_NORMAL 40 }; 41 42 struct ltq_mtd { 43 struct resource *res; 44 struct mtd_info *mtd; 45 struct map_info *map; 46 }; 47 48 static const char ltq_map_name[] = "ltq_nor"; 49 static const char * const ltq_probe_types[] = { "cmdlinepart", "ofpart", NULL }; 50 51 static map_word 52 ltq_read16(struct map_info *map, unsigned long adr) 53 { 54 unsigned long flags; 55 map_word temp; 56 57 if (map->map_priv_1 == LTQ_NOR_PROBING) 58 adr ^= 2; 59 spin_lock_irqsave(&ebu_lock, flags); 60 temp.x[0] = *(u16 *)(map->virt + adr); 61 spin_unlock_irqrestore(&ebu_lock, flags); 62 return temp; 63 } 64 65 static void 66 ltq_write16(struct map_info *map, map_word d, unsigned long adr) 67 { 68 unsigned long flags; 69 70 if (map->map_priv_1 == LTQ_NOR_PROBING) 71 adr ^= 2; 72 spin_lock_irqsave(&ebu_lock, flags); 73 *(u16 *)(map->virt + adr) = d.x[0]; 74 spin_unlock_irqrestore(&ebu_lock, flags); 75 } 76 77 /* 78 * The following 2 functions copy data between iomem and a cached memory 79 * section. As memcpy() makes use of pre-fetching we cannot use it here. 80 * The normal alternative of using memcpy_{to,from}io also makes use of 81 * memcpy() on MIPS so it is not applicable either. We are therefore stuck 82 * with having to use our own loop. 83 */ 84 static void 85 ltq_copy_from(struct map_info *map, void *to, 86 unsigned long from, ssize_t len) 87 { 88 unsigned char *f = (unsigned char *)map->virt + from; 89 unsigned char *t = (unsigned char *)to; 90 unsigned long flags; 91 92 spin_lock_irqsave(&ebu_lock, flags); 93 while (len--) 94 *t++ = *f++; 95 spin_unlock_irqrestore(&ebu_lock, flags); 96 } 97 98 static void 99 ltq_copy_to(struct map_info *map, unsigned long to, 100 const void *from, ssize_t len) 101 { 102 unsigned char *f = (unsigned char *)from; 103 unsigned char *t = (unsigned char *)map->virt + to; 104 unsigned long flags; 105 106 spin_lock_irqsave(&ebu_lock, flags); 107 while (len--) 108 *t++ = *f++; 109 spin_unlock_irqrestore(&ebu_lock, flags); 110 } 111 112 static int 113 ltq_mtd_probe(struct platform_device *pdev) 114 { 115 struct mtd_part_parser_data ppdata; 116 struct ltq_mtd *ltq_mtd; 117 struct cfi_private *cfi; 118 int err; 119 120 if (of_machine_is_compatible("lantiq,falcon") && 121 (ltq_boot_select() != BS_FLASH)) { 122 dev_err(&pdev->dev, "invalid bootstrap options\n"); 123 return -ENODEV; 124 } 125 126 ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL); 127 if (!ltq_mtd) 128 return -ENOMEM; 129 130 platform_set_drvdata(pdev, ltq_mtd); 131 132 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 133 if (!ltq_mtd->res) { 134 dev_err(&pdev->dev, "failed to get memory resource\n"); 135 return -ENOENT; 136 } 137 138 ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info), 139 GFP_KERNEL); 140 if (!ltq_mtd->map) 141 return -ENOMEM; 142 143 ltq_mtd->map->phys = ltq_mtd->res->start; 144 ltq_mtd->map->size = resource_size(ltq_mtd->res); 145 ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res); 146 if (IS_ERR(ltq_mtd->map->virt)) 147 return PTR_ERR(ltq_mtd->map->virt); 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 return -ENXIO; 163 } 164 165 ltq_mtd->mtd->owner = THIS_MODULE; 166 167 cfi = ltq_mtd->map->fldrv_priv; 168 cfi->addr_unlock1 ^= 1; 169 cfi->addr_unlock2 ^= 1; 170 171 ppdata.of_node = pdev->dev.of_node; 172 err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, 173 &ppdata, NULL, 0); 174 if (err) { 175 dev_err(&pdev->dev, "failed to add partitions\n"); 176 goto err_destroy; 177 } 178 179 return 0; 180 181 err_destroy: 182 map_destroy(ltq_mtd->mtd); 183 return err; 184 } 185 186 static int 187 ltq_mtd_remove(struct platform_device *pdev) 188 { 189 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev); 190 191 if (ltq_mtd && ltq_mtd->mtd) { 192 mtd_device_unregister(ltq_mtd->mtd); 193 map_destroy(ltq_mtd->mtd); 194 } 195 return 0; 196 } 197 198 static const struct of_device_id ltq_mtd_match[] = { 199 { .compatible = "lantiq,nor" }, 200 {}, 201 }; 202 MODULE_DEVICE_TABLE(of, ltq_mtd_match); 203 204 static struct platform_driver ltq_mtd_driver = { 205 .probe = ltq_mtd_probe, 206 .remove = ltq_mtd_remove, 207 .driver = { 208 .name = "ltq-nor", 209 .owner = THIS_MODULE, 210 .of_match_table = ltq_mtd_match, 211 }, 212 }; 213 214 module_platform_driver(ltq_mtd_driver); 215 216 MODULE_LICENSE("GPL"); 217 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); 218 MODULE_DESCRIPTION("Lantiq SoC NOR"); 219