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/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 #include <linux/of.h> 23 24 #include <lantiq_soc.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 const char ltq_map_name[] = "ltq_nor"; 48 static const char * const ltq_probe_types[] = { "cmdlinepart", "ofpart", 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 112 ltq_mtd_probe(struct platform_device *pdev) 113 { 114 struct mtd_part_parser_data ppdata; 115 struct ltq_mtd *ltq_mtd; 116 struct cfi_private *cfi; 117 int err; 118 119 if (of_machine_is_compatible("lantiq,falcon") && 120 (ltq_boot_select() != BS_FLASH)) { 121 dev_err(&pdev->dev, "invalid bootstrap options\n"); 122 return -ENODEV; 123 } 124 125 ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL); 126 if (!ltq_mtd) 127 return -ENOMEM; 128 129 platform_set_drvdata(pdev, ltq_mtd); 130 131 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 132 if (!ltq_mtd->res) { 133 dev_err(&pdev->dev, "failed to get memory resource\n"); 134 return -ENOENT; 135 } 136 137 ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info), 138 GFP_KERNEL); 139 if (!ltq_mtd->map) 140 return -ENOMEM; 141 142 ltq_mtd->map->phys = ltq_mtd->res->start; 143 ltq_mtd->map->size = resource_size(ltq_mtd->res); 144 ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res); 145 if (IS_ERR(ltq_mtd->map->virt)) 146 return PTR_ERR(ltq_mtd->map->virt); 147 148 ltq_mtd->map->name = ltq_map_name; 149 ltq_mtd->map->bankwidth = 2; 150 ltq_mtd->map->read = ltq_read16; 151 ltq_mtd->map->write = ltq_write16; 152 ltq_mtd->map->copy_from = ltq_copy_from; 153 ltq_mtd->map->copy_to = ltq_copy_to; 154 155 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING; 156 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map); 157 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL; 158 159 if (!ltq_mtd->mtd) { 160 dev_err(&pdev->dev, "probing failed\n"); 161 return -ENXIO; 162 } 163 164 ltq_mtd->mtd->owner = THIS_MODULE; 165 166 cfi = ltq_mtd->map->fldrv_priv; 167 cfi->addr_unlock1 ^= 1; 168 cfi->addr_unlock2 ^= 1; 169 170 ppdata.of_node = pdev->dev.of_node; 171 err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, 172 &ppdata, NULL, 0); 173 if (err) { 174 dev_err(&pdev->dev, "failed to add partitions\n"); 175 goto err_destroy; 176 } 177 178 return 0; 179 180 err_destroy: 181 map_destroy(ltq_mtd->mtd); 182 return err; 183 } 184 185 static int 186 ltq_mtd_remove(struct platform_device *pdev) 187 { 188 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev); 189 190 if (ltq_mtd && ltq_mtd->mtd) { 191 mtd_device_unregister(ltq_mtd->mtd); 192 map_destroy(ltq_mtd->mtd); 193 } 194 return 0; 195 } 196 197 static const struct of_device_id ltq_mtd_match[] = { 198 { .compatible = "lantiq,nor" }, 199 {}, 200 }; 201 MODULE_DEVICE_TABLE(of, ltq_mtd_match); 202 203 static struct platform_driver ltq_mtd_driver = { 204 .probe = ltq_mtd_probe, 205 .remove = ltq_mtd_remove, 206 .driver = { 207 .name = "ltq-nor", 208 .of_match_table = ltq_mtd_match, 209 }, 210 }; 211 212 module_platform_driver(ltq_mtd_driver); 213 214 MODULE_LICENSE("GPL"); 215 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); 216 MODULE_DESCRIPTION("Lantiq SoC NOR"); 217