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1da177e4 LT |
1 | /* |
2 | * | |
01675095 | 3 | * Copyright (C) 2001, 2006, 2008 MontaVista Software, <source@mvista.com> |
1da177e4 LT |
4 | * Copied and modified Carsten Langgaard's time.c |
5 | * | |
6 | * Carsten Langgaard, carstenl@mips.com | |
7 | * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. | |
8 | * | |
9 | * ######################################################################## | |
10 | * | |
11 | * This program is free software; you can distribute it and/or modify it | |
12 | * under the terms of the GNU General Public License (Version 2) as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | * This program is distributed in the hope it will be useful, but WITHOUT | |
16 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
17 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
18 | * for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License along | |
21 | * with this program; if not, write to the Free Software Foundation, Inc., | |
22 | * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. | |
23 | * | |
24 | * ######################################################################## | |
25 | * | |
26 | * Setting up the clock on the MIPS boards. | |
27 | * | |
c1dcb14e SS |
28 | * We provide the clock interrupt processing and the timer offset compute |
29 | * functions. If CONFIG_PM is selected, we also ensure the 32KHz timer is | |
30 | * available. -- Dan | |
1da177e4 LT |
31 | */ |
32 | ||
33 | #include <linux/types.h> | |
1da177e4 | 34 | #include <linux/init.h> |
1da177e4 | 35 | #include <linux/spinlock.h> |
1da177e4 | 36 | |
1da177e4 | 37 | #include <asm/mipsregs.h> |
1da177e4 | 38 | #include <asm/time.h> |
1da177e4 LT |
39 | #include <asm/mach-au1x00/au1000.h> |
40 | ||
eba8291b | 41 | static int no_au1xxx_32khz; |
fe359bf5 | 42 | extern int allow_au1k_wait; /* default off for CP0 Counter */ |
1da177e4 | 43 | |
1da177e4 | 44 | #ifdef CONFIG_PM |
3ce86ee1 PP |
45 | #if HZ < 100 || HZ > 1000 |
46 | #error "unsupported HZ value! Must be in [100,1000]" | |
47 | #endif | |
c1dcb14e | 48 | #define MATCH20_INC (328 * 100 / HZ) /* magic number 328 is for HZ=100... */ |
1da177e4 LT |
49 | static unsigned long last_pc0, last_match20; |
50 | #endif | |
51 | ||
52 | static DEFINE_SPINLOCK(time_lock); | |
53 | ||
1da177e4 | 54 | unsigned long wtimer; |
937a8015 | 55 | |
1da177e4 | 56 | #ifdef CONFIG_PM |
310a09d8 | 57 | static irqreturn_t counter0_irq(int irq, void *dev_id) |
1da177e4 LT |
58 | { |
59 | unsigned long pc0; | |
60 | int time_elapsed; | |
c1dcb14e | 61 | static int jiffie_drift; |
1da177e4 | 62 | |
1da177e4 LT |
63 | if (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20) { |
64 | /* should never happen! */ | |
3ce86ee1 PP |
65 | printk(KERN_WARNING "counter 0 w status error\n"); |
66 | return IRQ_NONE; | |
1da177e4 LT |
67 | } |
68 | ||
69 | pc0 = au_readl(SYS_TOYREAD); | |
c1dcb14e | 70 | if (pc0 < last_match20) |
1da177e4 LT |
71 | /* counter overflowed */ |
72 | time_elapsed = (0xffffffff - last_match20) + pc0; | |
c1dcb14e | 73 | else |
1da177e4 | 74 | time_elapsed = pc0 - last_match20; |
1da177e4 LT |
75 | |
76 | while (time_elapsed > 0) { | |
3171a030 | 77 | do_timer(1); |
1da177e4 | 78 | #ifndef CONFIG_SMP |
937a8015 | 79 | update_process_times(user_mode(get_irq_regs())); |
1da177e4 LT |
80 | #endif |
81 | time_elapsed -= MATCH20_INC; | |
82 | last_match20 += MATCH20_INC; | |
83 | jiffie_drift++; | |
84 | } | |
85 | ||
86 | last_pc0 = pc0; | |
87 | au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2); | |
88 | au_sync(); | |
89 | ||
c1dcb14e SS |
90 | /* |
91 | * Our counter ticks at 10.009765625 ms/tick, we we're running | |
92 | * almost 10 uS too slow per tick. | |
1da177e4 LT |
93 | */ |
94 | ||
95 | if (jiffie_drift >= 999) { | |
96 | jiffie_drift -= 999; | |
3171a030 | 97 | do_timer(1); /* increment jiffies by one */ |
1da177e4 | 98 | #ifndef CONFIG_SMP |
937a8015 | 99 | update_process_times(user_mode(get_irq_regs())); |
1da177e4 LT |
100 | #endif |
101 | } | |
3ce86ee1 PP |
102 | |
103 | return IRQ_HANDLED; | |
1da177e4 LT |
104 | } |
105 | ||
310a09d8 RB |
106 | struct irqaction counter0_action = { |
107 | .handler = counter0_irq, | |
108 | .flags = IRQF_DISABLED, | |
109 | .name = "alchemy-toy", | |
110 | .dev_id = NULL, | |
111 | }; | |
112 | ||
1da177e4 LT |
113 | /* When we wakeup from sleep, we have to "catch up" on all of the |
114 | * timer ticks we have missed. | |
115 | */ | |
c1dcb14e | 116 | void wakeup_counter0_adjust(void) |
1da177e4 LT |
117 | { |
118 | unsigned long pc0; | |
119 | int time_elapsed; | |
120 | ||
121 | pc0 = au_readl(SYS_TOYREAD); | |
c1dcb14e | 122 | if (pc0 < last_match20) |
1da177e4 LT |
123 | /* counter overflowed */ |
124 | time_elapsed = (0xffffffff - last_match20) + pc0; | |
c1dcb14e | 125 | else |
1da177e4 | 126 | time_elapsed = pc0 - last_match20; |
1da177e4 LT |
127 | |
128 | while (time_elapsed > 0) { | |
129 | time_elapsed -= MATCH20_INC; | |
130 | last_match20 += MATCH20_INC; | |
131 | } | |
132 | ||
133 | last_pc0 = pc0; | |
134 | au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2); | |
135 | au_sync(); | |
136 | ||
137 | } | |
138 | ||
c1dcb14e SS |
139 | /* This is just for debugging to set the timer for a sleep delay. */ |
140 | void wakeup_counter0_set(int ticks) | |
1da177e4 LT |
141 | { |
142 | unsigned long pc0; | |
143 | ||
144 | pc0 = au_readl(SYS_TOYREAD); | |
145 | last_pc0 = pc0; | |
146 | au_writel(last_match20 + (MATCH20_INC * ticks), SYS_TOYMATCH2); | |
147 | au_sync(); | |
148 | } | |
149 | #endif | |
150 | ||
c1dcb14e SS |
151 | /* |
152 | * I haven't found anyone that doesn't use a 12 MHz source clock, | |
1da177e4 LT |
153 | * but just in case..... |
154 | */ | |
1da177e4 | 155 | #define AU1000_SRC_CLK 12000000 |
1da177e4 LT |
156 | |
157 | /* | |
158 | * We read the real processor speed from the PLL. This is important | |
c1dcb14e | 159 | * because it is more accurate than computing it from the 32 KHz |
1da177e4 LT |
160 | * counter, if it exists. If we don't have an accurate processor |
161 | * speed, all of the peripherals that derive their clocks based on | |
162 | * this advertised speed will introduce error and sometimes not work | |
163 | * properly. This function is futher convoluted to still allow configurations | |
164 | * to do that in case they have really, really old silicon with a | |
c1dcb14e SS |
165 | * write-only PLL register, that we need the 32 KHz when power management |
166 | * "wait" is enabled, and we need to detect if the 32 KHz isn't present | |
1da177e4 LT |
167 | * but requested......got it? :-) -- Dan |
168 | */ | |
eba8291b | 169 | unsigned long calc_clock(void) |
1da177e4 | 170 | { |
1da177e4 LT |
171 | unsigned long cpu_speed; |
172 | unsigned long flags; | |
173 | unsigned long counter; | |
174 | ||
175 | spin_lock_irqsave(&time_lock, flags); | |
176 | ||
c1dcb14e | 177 | /* Power management cares if we don't have a 32 KHz counter. */ |
1da177e4 LT |
178 | no_au1xxx_32khz = 0; |
179 | counter = au_readl(SYS_COUNTER_CNTRL); | |
180 | if (counter & SYS_CNTRL_E0) { | |
181 | int trim_divide = 16; | |
182 | ||
183 | au_writel(counter | SYS_CNTRL_EN1, SYS_COUNTER_CNTRL); | |
184 | ||
185 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S); | |
186 | /* RTC now ticks at 32.768/16 kHz */ | |
c1dcb14e | 187 | au_writel(trim_divide - 1, SYS_RTCTRIM); |
1da177e4 LT |
188 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_T1S); |
189 | ||
190 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S); | |
49a89efb | 191 | au_writel(0, SYS_TOYWRITE); |
1da177e4 | 192 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C1S); |
758e285f SS |
193 | } else |
194 | no_au1xxx_32khz = 1; | |
1da177e4 | 195 | |
758e285f SS |
196 | /* |
197 | * On early Au1000, sys_cpupll was write-only. Since these | |
198 | * silicon versions of Au1000 are not sold by AMD, we don't bend | |
199 | * over backwards trying to determine the frequency. | |
200 | */ | |
074cf656 | 201 | if (au1xxx_cpu_has_pll_wo()) |
758e285f SS |
202 | #ifdef CONFIG_SOC_AU1000_FREQUENCY |
203 | cpu_speed = CONFIG_SOC_AU1000_FREQUENCY; | |
204 | #else | |
205 | cpu_speed = 396000000; | |
206 | #endif | |
207 | else | |
1da177e4 | 208 | cpu_speed = (au_readl(SYS_CPUPLL) & 0x0000003f) * AU1000_SRC_CLK; |
c1dcb14e | 209 | /* On Alchemy CPU:counter ratio is 1:1 */ |
53c1b192 | 210 | mips_hpt_frequency = cpu_speed; |
c1dcb14e SS |
211 | /* Equation: Baudrate = CPU / (SD * 2 * CLKDIV * 16) */ |
212 | set_au1x00_uart_baud_base(cpu_speed / (2 * ((int)(au_readl(SYS_POWERCTRL) | |
213 | & 0x03) + 2) * 16)); | |
1da177e4 | 214 | spin_unlock_irqrestore(&time_lock, flags); |
eba8291b | 215 | return cpu_speed; |
1da177e4 LT |
216 | } |
217 | ||
bc2f2a24 | 218 | void __init plat_time_init(void) |
1da177e4 | 219 | { |
eba8291b | 220 | unsigned int est_freq = calc_clock(); |
1da177e4 | 221 | |
1da177e4 LT |
222 | est_freq += 5000; /* round */ |
223 | est_freq -= est_freq%10000; | |
074cf656 | 224 | printk(KERN_INFO "(PRId %08x) @ %u.%02u MHz\n", read_c0_prid(), |
c1dcb14e SS |
225 | est_freq / 1000000, ((est_freq % 1000000) * 100) / 1000000); |
226 | set_au1x00_speed(est_freq); | |
1da177e4 | 227 | |
1da177e4 LT |
228 | #ifdef CONFIG_PM |
229 | /* | |
230 | * setup counter 0, since it keeps ticking after a | |
231 | * 'wait' instruction has been executed. The CP0 timer and | |
232 | * counter 1 do NOT continue running after 'wait' | |
233 | * | |
234 | * It's too early to call request_irq() here, so we handle | |
235 | * counter 0 interrupt as a special irq and it doesn't show | |
236 | * up under /proc/interrupts. | |
237 | * | |
c1dcb14e | 238 | * Check to ensure we really have a 32 KHz oscillator before |
1da177e4 LT |
239 | * we do this. |
240 | */ | |
01675095 | 241 | if (no_au1xxx_32khz) |
c1dcb14e | 242 | printk(KERN_WARNING "WARNING: no 32KHz clock found.\n"); |
1da177e4 LT |
243 | else { |
244 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S); | |
245 | au_writel(0, SYS_TOYWRITE); | |
246 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_C0S); | |
247 | ||
c1dcb14e | 248 | au_writel(au_readl(SYS_WAKEMSK) | (1 << 8), SYS_WAKEMSK); |
1da177e4 LT |
249 | au_writel(~0, SYS_WAKESRC); |
250 | au_sync(); | |
251 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20); | |
252 | ||
c1dcb14e | 253 | /* Setup match20 to interrupt once every HZ */ |
1da177e4 LT |
254 | last_pc0 = last_match20 = au_readl(SYS_TOYREAD); |
255 | au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2); | |
256 | au_sync(); | |
257 | while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20); | |
310a09d8 | 258 | setup_irq(AU1000_TOY_MATCH2_INT, &counter0_action); |
1da177e4 | 259 | |
c1dcb14e | 260 | /* We can use the real 'wait' instruction. */ |
494900af | 261 | allow_au1k_wait = 1; |
1da177e4 LT |
262 | } |
263 | ||
1da177e4 LT |
264 | #endif |
265 | } |