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