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