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 = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL); 127 platform_set_drvdata(pdev, ltq_mtd); 128 129 ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 130 if (!ltq_mtd->res) { 131 dev_err(&pdev->dev, "failed to get memory resource\n"); 132 err = -ENOENT; 133 goto err_out; 134 } 135 136 ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL); 137 ltq_mtd->map->phys = ltq_mtd->res->start; 138 ltq_mtd->map->size = resource_size(ltq_mtd->res); 139 ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res); 140 if (IS_ERR(ltq_mtd->map->virt)) { 141 err = PTR_ERR(ltq_mtd->map->virt); 142 goto err_out; 143 } 144 145 ltq_mtd->map->name = ltq_map_name; 146 ltq_mtd->map->bankwidth = 2; 147 ltq_mtd->map->read = ltq_read16; 148 ltq_mtd->map->write = ltq_write16; 149 ltq_mtd->map->copy_from = ltq_copy_from; 150 ltq_mtd->map->copy_to = ltq_copy_to; 151 152 ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING; 153 ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map); 154 ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL; 155 156 if (!ltq_mtd->mtd) { 157 dev_err(&pdev->dev, "probing failed\n"); 158 err = -ENXIO; 159 goto err_free; 160 } 161 162 ltq_mtd->mtd->owner = THIS_MODULE; 163 164 cfi = ltq_mtd->map->fldrv_priv; 165 cfi->addr_unlock1 ^= 1; 166 cfi->addr_unlock2 ^= 1; 167 168 ppdata.of_node = pdev->dev.of_node; 169 err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, 170 &ppdata, NULL, 0); 171 if (err) { 172 dev_err(&pdev->dev, "failed to add partitions\n"); 173 goto err_destroy; 174 } 175 176 return 0; 177 178 err_destroy: 179 map_destroy(ltq_mtd->mtd); 180 err_free: 181 kfree(ltq_mtd->map); 182 err_out: 183 kfree(ltq_mtd); 184 return err; 185 } 186 187 static int 188 ltq_mtd_remove(struct platform_device *pdev) 189 { 190 struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev); 191 192 if (ltq_mtd) { 193 if (ltq_mtd->mtd) { 194 mtd_device_unregister(ltq_mtd->mtd); 195 map_destroy(ltq_mtd->mtd); 196 } 197 kfree(ltq_mtd->map); 198 kfree(ltq_mtd); 199 } 200 return 0; 201 } 202 203 static const struct of_device_id ltq_mtd_match[] = { 204 { .compatible = "lantiq,nor" }, 205 {}, 206 }; 207 MODULE_DEVICE_TABLE(of, ltq_mtd_match); 208 209 static struct platform_driver ltq_mtd_driver = { 210 .probe = ltq_mtd_probe, 211 .remove = ltq_mtd_remove, 212 .driver = { 213 .name = "ltq-nor", 214 .owner = THIS_MODULE, 215 .of_match_table = ltq_mtd_match, 216 }, 217 }; 218 219 module_platform_driver(ltq_mtd_driver); 220 221 MODULE_LICENSE("GPL"); 222 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>"); 223 MODULE_DESCRIPTION("Lantiq SoC NOR"); 224