1 /*
2  *   Octeon Bootbus flash setup
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2007, 2008 Cavium Networks
9  */
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/semaphore.h>
13 #include <linux/mtd/mtd.h>
14 #include <linux/mtd/map.h>
15 #include <linux/of.h>
16 #include <linux/platform_device.h>
17 #include <linux/mtd/partitions.h>
18 
19 #include <asm/octeon/octeon.h>
20 
21 static struct map_info flash_map;
22 static struct mtd_info *mymtd;
23 static const char *part_probe_types[] = {
24 	"cmdlinepart",
25 #ifdef CONFIG_MTD_REDBOOT_PARTS
26 	"RedBoot",
27 #endif
28 	NULL
29 };
30 
31 static map_word octeon_flash_map_read(struct map_info *map, unsigned long ofs)
32 {
33 	map_word r;
34 
35 	down(&octeon_bootbus_sem);
36 	r = inline_map_read(map, ofs);
37 	up(&octeon_bootbus_sem);
38 
39 	return r;
40 }
41 
42 static void octeon_flash_map_write(struct map_info *map, const map_word datum,
43 				   unsigned long ofs)
44 {
45 	down(&octeon_bootbus_sem);
46 	inline_map_write(map, datum, ofs);
47 	up(&octeon_bootbus_sem);
48 }
49 
50 static void octeon_flash_map_copy_from(struct map_info *map, void *to,
51 				       unsigned long from, ssize_t len)
52 {
53 	down(&octeon_bootbus_sem);
54 	inline_map_copy_from(map, to, from, len);
55 	up(&octeon_bootbus_sem);
56 }
57 
58 static void octeon_flash_map_copy_to(struct map_info *map, unsigned long to,
59 				     const void *from, ssize_t len)
60 {
61 	down(&octeon_bootbus_sem);
62 	inline_map_copy_to(map, to, from, len);
63 	up(&octeon_bootbus_sem);
64 }
65 
66 /*
67  * Module/ driver initialization.
68  *
69  * Returns Zero on success
70  */
71 static int octeon_flash_probe(struct platform_device *pdev)
72 {
73 	union cvmx_mio_boot_reg_cfgx region_cfg;
74 	u32 cs;
75 	int r;
76 	struct device_node *np = pdev->dev.of_node;
77 
78 	r = of_property_read_u32(np, "reg", &cs);
79 	if (r)
80 		return r;
81 
82 	/*
83 	 * Read the bootbus region 0 setup to determine the base
84 	 * address of the flash.
85 	 */
86 	region_cfg.u64 = cvmx_read_csr(CVMX_MIO_BOOT_REG_CFGX(cs));
87 	if (region_cfg.s.en) {
88 		/*
89 		 * The bootloader always takes the flash and sets its
90 		 * address so the entire flash fits below
91 		 * 0x1fc00000. This way the flash aliases to
92 		 * 0x1fc00000 for booting. Software can access the
93 		 * full flash at the true address, while core boot can
94 		 * access 4MB.
95 		 */
96 		/* Use this name so old part lines work */
97 		flash_map.name = "phys_mapped_flash";
98 		flash_map.phys = region_cfg.s.base << 16;
99 		flash_map.size = 0x1fc00000 - flash_map.phys;
100 		/* 8-bit bus (0 + 1) or 16-bit bus (1 + 1) */
101 		flash_map.bankwidth = region_cfg.s.width + 1;
102 		flash_map.virt = ioremap(flash_map.phys, flash_map.size);
103 		pr_notice("Bootbus flash: Setting flash for %luMB flash at "
104 			  "0x%08llx\n", flash_map.size >> 20, flash_map.phys);
105 		WARN_ON(!map_bankwidth_supported(flash_map.bankwidth));
106 		flash_map.read = octeon_flash_map_read;
107 		flash_map.write = octeon_flash_map_write;
108 		flash_map.copy_from = octeon_flash_map_copy_from;
109 		flash_map.copy_to = octeon_flash_map_copy_to;
110 		mymtd = do_map_probe("cfi_probe", &flash_map);
111 		if (mymtd) {
112 			mymtd->owner = THIS_MODULE;
113 			mtd_device_parse_register(mymtd, part_probe_types,
114 						  NULL, NULL, 0);
115 		} else {
116 			pr_err("Failed to register MTD device for flash\n");
117 		}
118 	}
119 	return 0;
120 }
121 
122 static const struct of_device_id of_flash_match[] = {
123 	{
124 		.compatible	= "cfi-flash",
125 	},
126 	{ },
127 };
128 MODULE_DEVICE_TABLE(of, of_flash_match);
129 
130 static struct platform_driver of_flash_driver = {
131 	.driver = {
132 		.name = "octeon-of-flash",
133 		.of_match_table = of_flash_match,
134 	},
135 	.probe		= octeon_flash_probe,
136 };
137 
138 static int octeon_flash_init(void)
139 {
140 	return platform_driver_register(&of_flash_driver);
141 }
142 late_initcall(octeon_flash_init);
143 
144 MODULE_LICENSE("GPL");
145