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