i2c: normal_i2c can be made const (remaining drivers)
[linux-2.6] / arch / arm / plat-omap / common.c
1 /*
2  * linux/arch/arm/plat-omap/common.c
3  *
4  * Code common to all OMAP machines.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/delay.h>
14 #include <linux/pm.h>
15 #include <linux/console.h>
16 #include <linux/serial.h>
17 #include <linux/tty.h>
18 #include <linux/serial_8250.h>
19 #include <linux/serial_reg.h>
20 #include <linux/clk.h>
21
22 #include <asm/hardware.h>
23 #include <asm/system.h>
24 #include <asm/pgtable.h>
25 #include <asm/mach/map.h>
26 #include <asm/io.h>
27 #include <asm/setup.h>
28
29 #include <asm/arch/board.h>
30 #include <asm/arch/mux.h>
31 #include <asm/arch/fpga.h>
32
33 #include <asm/arch/clock.h>
34
35 #define NO_LENGTH_CHECK 0xffffffff
36
37 unsigned char omap_bootloader_tag[512];
38 int omap_bootloader_tag_len;
39
40 struct omap_board_config_kernel *omap_board_config;
41 int omap_board_config_size;
42
43 static const void *get_config(u16 tag, size_t len, int skip, size_t *len_out)
44 {
45         struct omap_board_config_kernel *kinfo = NULL;
46         int i;
47
48 #ifdef CONFIG_OMAP_BOOT_TAG
49         struct omap_board_config_entry *info = NULL;
50
51         if (omap_bootloader_tag_len > 4)
52                 info = (struct omap_board_config_entry *) omap_bootloader_tag;
53         while (info != NULL) {
54                 u8 *next;
55
56                 if (info->tag == tag) {
57                         if (skip == 0)
58                                 break;
59                         skip--;
60                 }
61
62                 if ((info->len & 0x03) != 0) {
63                         /* We bail out to avoid an alignment fault */
64                         printk(KERN_ERR "OMAP peripheral config: Length (%d) not word-aligned (tag %04x)\n",
65                                info->len, info->tag);
66                         return NULL;
67                 }
68                 next = (u8 *) info + sizeof(*info) + info->len;
69                 if (next >= omap_bootloader_tag + omap_bootloader_tag_len)
70                         info = NULL;
71                 else
72                         info = (struct omap_board_config_entry *) next;
73         }
74         if (info != NULL) {
75                 /* Check the length as a lame attempt to check for
76                  * binary inconsistency. */
77                 if (len != NO_LENGTH_CHECK) {
78                         /* Word-align len */
79                         if (len & 0x03)
80                                 len = (len + 3) & ~0x03;
81                         if (info->len != len) {
82                                 printk(KERN_ERR "OMAP peripheral config: Length mismatch with tag %x (want %d, got %d)\n",
83                                        tag, len, info->len);
84                                 return NULL;
85                         }
86                 }
87                 if (len_out != NULL)
88                         *len_out = info->len;
89                 return info->data;
90         }
91 #endif
92         /* Try to find the config from the board-specific structures
93          * in the kernel. */
94         for (i = 0; i < omap_board_config_size; i++) {
95                 if (omap_board_config[i].tag == tag) {
96                         if (skip == 0) {
97                                 kinfo = &omap_board_config[i];
98                                 break;
99                         } else {
100                                 skip--;
101                         }
102                 }
103         }
104         if (kinfo == NULL)
105                 return NULL;
106         return kinfo->data;
107 }
108
109 const void *__omap_get_config(u16 tag, size_t len, int nr)
110 {
111         return get_config(tag, len, nr, NULL);
112 }
113 EXPORT_SYMBOL(__omap_get_config);
114
115 const void *omap_get_var_config(u16 tag, size_t *len)
116 {
117         return get_config(tag, NO_LENGTH_CHECK, 0, len);
118 }
119 EXPORT_SYMBOL(omap_get_var_config);
120
121 static int __init omap_add_serial_console(void)
122 {
123         const struct omap_serial_console_config *con_info;
124         const struct omap_uart_config *uart_info;
125         static char speed[11], *opt = NULL;
126         int line, i, uart_idx;
127
128         uart_info = omap_get_config(OMAP_TAG_UART, struct omap_uart_config);
129         con_info = omap_get_config(OMAP_TAG_SERIAL_CONSOLE,
130                                         struct omap_serial_console_config);
131         if (uart_info == NULL || con_info == NULL)
132                 return 0;
133
134         if (con_info->console_uart == 0)
135                 return 0;
136
137         if (con_info->console_speed) {
138                 snprintf(speed, sizeof(speed), "%u", con_info->console_speed);
139                 opt = speed;
140         }
141
142         uart_idx = con_info->console_uart - 1;
143         if (uart_idx >= OMAP_MAX_NR_PORTS) {
144                 printk(KERN_INFO "Console: external UART#%d. "
145                         "Not adding it as console this time.\n",
146                         uart_idx + 1);
147                 return 0;
148         }
149         if (!(uart_info->enabled_uarts & (1 << uart_idx))) {
150                 printk(KERN_ERR "Console: Selected UART#%d is "
151                         "not enabled for this platform\n",
152                         uart_idx + 1);
153                 return -1;
154         }
155         line = 0;
156         for (i = 0; i < uart_idx; i++) {
157                 if (uart_info->enabled_uarts & (1 << i))
158                         line++;
159         }
160         return add_preferred_console("ttyS", line, opt);
161 }
162 console_initcall(omap_add_serial_console);
163
164
165 /*
166  * 32KHz clocksource ... always available, on pretty most chips except
167  * OMAP 730 and 1510.  Other timers could be used as clocksources, with
168  * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
169  * but systems won't necessarily want to spend resources that way.
170  */
171
172 #if defined(CONFIG_ARCH_OMAP16XX)
173 #define TIMER_32K_SYNCHRONIZED          0xfffbc410
174 #elif defined(CONFIG_ARCH_OMAP24XX)
175 #define TIMER_32K_SYNCHRONIZED          (OMAP24XX_32KSYNCT_BASE + 0x10)
176 #endif
177
178 #ifdef  TIMER_32K_SYNCHRONIZED
179
180 #include <linux/clocksource.h>
181
182 static cycle_t omap_32k_read(void)
183 {
184         return omap_readl(TIMER_32K_SYNCHRONIZED);
185 }
186
187 static struct clocksource clocksource_32k = {
188         .name           = "32k_counter",
189         .rating         = 250,
190         .read           = omap_32k_read,
191         .mask           = CLOCKSOURCE_MASK(32),
192         .shift          = 10,
193         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
194 };
195
196 static int __init omap_init_clocksource_32k(void)
197 {
198         static char err[] __initdata = KERN_ERR
199                         "%s: can't register clocksource!\n";
200
201         if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
202                 clocksource_32k.mult = clocksource_hz2mult(32768,
203                                             clocksource_32k.shift);
204
205                 if (clocksource_register(&clocksource_32k))
206                         printk(err, clocksource_32k.name);
207         }
208         return 0;
209 }
210 arch_initcall(omap_init_clocksource_32k);
211
212 #endif  /* TIMER_32K_SYNCHRONIZED */