1/*
2 *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
3 *  Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
4 *  Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
5 *
6 *  This program is free software; you can redistribute  it and/or modify it
7 *  under  the terms of  the GNU General  Public License as published by the
8 *  Free Software Foundation;  either version 2 of the  License, or (at your
9 *  option) any later version.
10 *
11 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
12 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
13 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
14 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
15 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
16 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
17 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
18 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
19 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
20 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
21 *
22 *  You should have received a copy of the  GNU General Public License along
23 *  with this program; if not, write  to the Free Software Foundation, Inc.,
24 *  675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27#include <linux/init.h>
28#include <linux/types.h>
29#include <linux/kernel.h>
30#include <linux/spinlock.h>
31#include <linux/ssb/ssb_driver_chipcommon.h>
32#include <linux/ssb/ssb_regs.h>
33#include <linux/smp.h>
34#include <asm/bootinfo.h>
35#include <bcm47xx.h>
36#include <bcm47xx_board.h>
37
38static char bcm47xx_system_type[20] = "Broadcom BCM47XX";
39
40const char *get_system_type(void)
41{
42	return bcm47xx_system_type;
43}
44
45__init void bcm47xx_set_system_type(u16 chip_id)
46{
47	snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type),
48		 (chip_id > 0x9999) ? "Broadcom BCM%d" :
49				      "Broadcom BCM%04X",
50		 chip_id);
51}
52
53static unsigned long lowmem __initdata;
54
55static __init void prom_init_mem(void)
56{
57	unsigned long mem;
58	unsigned long max;
59	unsigned long off;
60	struct cpuinfo_mips *c = &current_cpu_data;
61
62	/* Figure out memory size by finding aliases.
63	 *
64	 * We should theoretically use the mapping from CFE using cfe_enummem().
65	 * However as the BCM47XX is mostly used on low-memory systems, we
66	 * want to reuse the memory used by CFE (around 4MB). That means cfe_*
67	 * functions stop to work at some point during the boot, we should only
68	 * call them at the beginning of the boot.
69	 *
70	 * BCM47XX uses 128MB for addressing the ram, if the system contains
71	 * less that that amount of ram it remaps the ram more often into the
72	 * available space.
73	 */
74
75	/* Physical address, without mapping to any kernel segment */
76	off = CPHYSADDR((unsigned long)prom_init);
77
78	/* Accessing memory after 128 MiB will cause an exception */
79	max = 128 << 20;
80
81	for (mem = 1 << 20; mem < max; mem += 1 << 20) {
82		/* Loop condition may be not enough, off may be over 1 MiB */
83		if (off + mem >= max) {
84			mem = max;
85			pr_debug("Assume 128MB RAM\n");
86			break;
87		}
88		if (!memcmp(prom_init, prom_init + mem, 32))
89			break;
90	}
91	lowmem = mem;
92
93	/* Ignoring the last page when ddr size is 128M. Cached
94	 * accesses to last page is causing the processor to prefetch
95	 * using address above 128M stepping out of the ddr address
96	 * space.
97	 */
98	if (c->cputype == CPU_74K && (mem == (128  << 20)))
99		mem -= 0x1000;
100	add_memory_region(0, mem, BOOT_MEM_RAM);
101}
102
103/*
104 * This is the first serial on the chip common core, it is at this position
105 * for sb (ssb) and ai (bcma) bus.
106 */
107#define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)
108
109void __init prom_init(void)
110{
111	prom_init_mem();
112	setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
113}
114
115void __init prom_free_prom_memory(void)
116{
117}
118
119#if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)
120
121#define EXTVBASE	0xc0000000
122#define ENTRYLO(x)	((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)
123
124#include <asm/tlbflush.h>
125
126/* Stripped version of tlb_init, with the call to build_tlb_refill_handler
127 * dropped. Calling it at this stage causes a hang.
128 */
129void __cpuinit early_tlb_init(void)
130{
131	write_c0_pagemask(PM_DEFAULT_MASK);
132	write_c0_wired(0);
133	temp_tlb_entry = current_cpu_data.tlbsize - 1;
134	local_flush_tlb_all();
135}
136
137void __init bcm47xx_prom_highmem_init(void)
138{
139	unsigned long off = (unsigned long)prom_init;
140	unsigned long extmem = 0;
141	bool highmem_region = false;
142
143	if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
144		return;
145
146	if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
147		highmem_region = true;
148
149	if (lowmem != 128 << 20 || !highmem_region)
150		return;
151
152	early_tlb_init();
153
154	/* Add one temporary TLB entry to map SDRAM Region 2.
155	 *      Physical        Virtual
156	 *      0x80000000      0xc0000000      (1st: 256MB)
157	 *      0x90000000      0xd0000000      (2nd: 256MB)
158	 */
159	add_temporary_entry(ENTRYLO(0x80000000),
160			    ENTRYLO(0x80000000 + (256 << 20)),
161			    EXTVBASE, PM_256M);
162
163	off = EXTVBASE + __pa(off);
164	for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
165		if (!memcmp(prom_init, (void *)(off + extmem), 16))
166			break;
167	}
168	extmem -= lowmem;
169
170	early_tlb_init();
171
172	if (!extmem)
173		return;
174
175	pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
176		extmem >> 20);
177
178	/* TODO: Register extra memory */
179}
180
181#endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */
182