Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * linux/arch/arm/mach-integrator/core.c |
| 3 | * |
| 4 | * Copyright (C) 2000-2003 Deep Blue Solutions Ltd |
| 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/types.h> |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/device.h> |
| 14 | #include <linux/spinlock.h> |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <linux/sched.h> |
| 17 | |
| 18 | #include <asm/hardware.h> |
| 19 | #include <asm/irq.h> |
| 20 | #include <asm/io.h> |
| 21 | #include <asm/hardware/amba.h> |
| 22 | #include <asm/arch/cm.h> |
| 23 | #include <asm/system.h> |
| 24 | #include <asm/leds.h> |
| 25 | #include <asm/mach/time.h> |
| 26 | |
| 27 | #include "common.h" |
| 28 | |
| 29 | static struct amba_device rtc_device = { |
| 30 | .dev = { |
| 31 | .bus_id = "mb:15", |
| 32 | }, |
| 33 | .res = { |
| 34 | .start = INTEGRATOR_RTC_BASE, |
| 35 | .end = INTEGRATOR_RTC_BASE + SZ_4K - 1, |
| 36 | .flags = IORESOURCE_MEM, |
| 37 | }, |
| 38 | .irq = { IRQ_RTCINT, NO_IRQ }, |
| 39 | .periphid = 0x00041030, |
| 40 | }; |
| 41 | |
| 42 | static struct amba_device uart0_device = { |
| 43 | .dev = { |
| 44 | .bus_id = "mb:16", |
| 45 | }, |
| 46 | .res = { |
| 47 | .start = INTEGRATOR_UART0_BASE, |
| 48 | .end = INTEGRATOR_UART0_BASE + SZ_4K - 1, |
| 49 | .flags = IORESOURCE_MEM, |
| 50 | }, |
| 51 | .irq = { IRQ_UARTINT0, NO_IRQ }, |
| 52 | .periphid = 0x0041010, |
| 53 | }; |
| 54 | |
| 55 | static struct amba_device uart1_device = { |
| 56 | .dev = { |
| 57 | .bus_id = "mb:17", |
| 58 | }, |
| 59 | .res = { |
| 60 | .start = INTEGRATOR_UART1_BASE, |
| 61 | .end = INTEGRATOR_UART1_BASE + SZ_4K - 1, |
| 62 | .flags = IORESOURCE_MEM, |
| 63 | }, |
| 64 | .irq = { IRQ_UARTINT1, NO_IRQ }, |
| 65 | .periphid = 0x0041010, |
| 66 | }; |
| 67 | |
| 68 | static struct amba_device kmi0_device = { |
| 69 | .dev = { |
| 70 | .bus_id = "mb:18", |
| 71 | }, |
| 72 | .res = { |
| 73 | .start = KMI0_BASE, |
| 74 | .end = KMI0_BASE + SZ_4K - 1, |
| 75 | .flags = IORESOURCE_MEM, |
| 76 | }, |
| 77 | .irq = { IRQ_KMIINT0, NO_IRQ }, |
| 78 | .periphid = 0x00041050, |
| 79 | }; |
| 80 | |
| 81 | static struct amba_device kmi1_device = { |
| 82 | .dev = { |
| 83 | .bus_id = "mb:19", |
| 84 | }, |
| 85 | .res = { |
| 86 | .start = KMI1_BASE, |
| 87 | .end = KMI1_BASE + SZ_4K - 1, |
| 88 | .flags = IORESOURCE_MEM, |
| 89 | }, |
| 90 | .irq = { IRQ_KMIINT1, NO_IRQ }, |
| 91 | .periphid = 0x00041050, |
| 92 | }; |
| 93 | |
| 94 | static struct amba_device *amba_devs[] __initdata = { |
| 95 | &rtc_device, |
| 96 | &uart0_device, |
| 97 | &uart1_device, |
| 98 | &kmi0_device, |
| 99 | &kmi1_device, |
| 100 | }; |
| 101 | |
| 102 | static int __init integrator_init(void) |
| 103 | { |
| 104 | int i; |
| 105 | |
| 106 | for (i = 0; i < ARRAY_SIZE(amba_devs); i++) { |
| 107 | struct amba_device *d = amba_devs[i]; |
| 108 | amba_device_register(d, &iomem_resource); |
| 109 | } |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | arch_initcall(integrator_init); |
| 115 | |
| 116 | #define CM_CTRL IO_ADDRESS(INTEGRATOR_HDR_BASE) + INTEGRATOR_HDR_CTRL_OFFSET |
| 117 | |
| 118 | static DEFINE_SPINLOCK(cm_lock); |
| 119 | |
| 120 | /** |
| 121 | * cm_control - update the CM_CTRL register. |
| 122 | * @mask: bits to change |
| 123 | * @set: bits to set |
| 124 | */ |
| 125 | void cm_control(u32 mask, u32 set) |
| 126 | { |
| 127 | unsigned long flags; |
| 128 | u32 val; |
| 129 | |
| 130 | spin_lock_irqsave(&cm_lock, flags); |
| 131 | val = readl(CM_CTRL) & ~mask; |
| 132 | writel(val | set, CM_CTRL); |
| 133 | spin_unlock_irqrestore(&cm_lock, flags); |
| 134 | } |
| 135 | |
| 136 | EXPORT_SYMBOL(cm_control); |
| 137 | |
| 138 | /* |
| 139 | * Where is the timer (VA)? |
| 140 | */ |
| 141 | #define TIMER0_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000000) |
| 142 | #define TIMER1_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000100) |
| 143 | #define TIMER2_VA_BASE (IO_ADDRESS(INTEGRATOR_CT_BASE)+0x00000200) |
| 144 | #define VA_IC_BASE IO_ADDRESS(INTEGRATOR_IC_BASE) |
| 145 | |
| 146 | /* |
| 147 | * How long is the timer interval? |
| 148 | */ |
| 149 | #define TIMER_INTERVAL (TICKS_PER_uSEC * mSEC_10) |
| 150 | #if TIMER_INTERVAL >= 0x100000 |
| 151 | #define TICKS2USECS(x) (256 * (x) / TICKS_PER_uSEC) |
| 152 | #elif TIMER_INTERVAL >= 0x10000 |
| 153 | #define TICKS2USECS(x) (16 * (x) / TICKS_PER_uSEC) |
| 154 | #else |
| 155 | #define TICKS2USECS(x) ((x) / TICKS_PER_uSEC) |
| 156 | #endif |
| 157 | |
| 158 | /* |
| 159 | * What does it look like? |
| 160 | */ |
| 161 | typedef struct TimerStruct { |
| 162 | unsigned long TimerLoad; |
| 163 | unsigned long TimerValue; |
| 164 | unsigned long TimerControl; |
| 165 | unsigned long TimerClear; |
| 166 | } TimerStruct_t; |
| 167 | |
| 168 | static unsigned long timer_reload; |
| 169 | |
| 170 | /* |
| 171 | * Returns number of ms since last clock interrupt. Note that interrupts |
| 172 | * will have been disabled by do_gettimeoffset() |
| 173 | */ |
| 174 | unsigned long integrator_gettimeoffset(void) |
| 175 | { |
| 176 | volatile TimerStruct_t *timer1 = (TimerStruct_t *)TIMER1_VA_BASE; |
| 177 | unsigned long ticks1, ticks2, status; |
| 178 | |
| 179 | /* |
| 180 | * Get the current number of ticks. Note that there is a race |
| 181 | * condition between us reading the timer and checking for |
| 182 | * an interrupt. We get around this by ensuring that the |
| 183 | * counter has not reloaded between our two reads. |
| 184 | */ |
| 185 | ticks2 = timer1->TimerValue & 0xffff; |
| 186 | do { |
| 187 | ticks1 = ticks2; |
| 188 | status = __raw_readl(VA_IC_BASE + IRQ_RAW_STATUS); |
| 189 | ticks2 = timer1->TimerValue & 0xffff; |
| 190 | } while (ticks2 > ticks1); |
| 191 | |
| 192 | /* |
| 193 | * Number of ticks since last interrupt. |
| 194 | */ |
| 195 | ticks1 = timer_reload - ticks2; |
| 196 | |
| 197 | /* |
| 198 | * Interrupt pending? If so, we've reloaded once already. |
| 199 | */ |
| 200 | if (status & (1 << IRQ_TIMERINT1)) |
| 201 | ticks1 += timer_reload; |
| 202 | |
| 203 | /* |
| 204 | * Convert the ticks to usecs |
| 205 | */ |
| 206 | return TICKS2USECS(ticks1); |
| 207 | } |
| 208 | |
| 209 | /* |
| 210 | * IRQ handler for the timer |
| 211 | */ |
| 212 | static irqreturn_t |
| 213 | integrator_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 214 | { |
| 215 | volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE; |
| 216 | |
| 217 | write_seqlock(&xtime_lock); |
| 218 | |
| 219 | // ...clear the interrupt |
| 220 | timer1->TimerClear = 1; |
| 221 | |
| 222 | timer_tick(regs); |
| 223 | |
| 224 | write_sequnlock(&xtime_lock); |
| 225 | |
| 226 | return IRQ_HANDLED; |
| 227 | } |
| 228 | |
| 229 | static struct irqaction integrator_timer_irq = { |
| 230 | .name = "Integrator Timer Tick", |
| 231 | .flags = SA_INTERRUPT, |
| 232 | .handler = integrator_timer_interrupt |
| 233 | }; |
| 234 | |
| 235 | /* |
| 236 | * Set up timer interrupt, and return the current time in seconds. |
| 237 | */ |
| 238 | void __init integrator_time_init(unsigned long reload, unsigned int ctrl) |
| 239 | { |
| 240 | volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *)TIMER0_VA_BASE; |
| 241 | volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *)TIMER1_VA_BASE; |
| 242 | volatile TimerStruct_t *timer2 = (volatile TimerStruct_t *)TIMER2_VA_BASE; |
| 243 | unsigned int timer_ctrl = 0x80 | 0x40; /* periodic */ |
| 244 | |
| 245 | timer_reload = reload; |
| 246 | timer_ctrl |= ctrl; |
| 247 | |
| 248 | if (timer_reload > 0x100000) { |
| 249 | timer_reload >>= 8; |
| 250 | timer_ctrl |= 0x08; /* /256 */ |
| 251 | } else if (timer_reload > 0x010000) { |
| 252 | timer_reload >>= 4; |
| 253 | timer_ctrl |= 0x04; /* /16 */ |
| 254 | } |
| 255 | |
| 256 | /* |
| 257 | * Initialise to a known state (all timers off) |
| 258 | */ |
| 259 | timer0->TimerControl = 0; |
| 260 | timer1->TimerControl = 0; |
| 261 | timer2->TimerControl = 0; |
| 262 | |
| 263 | timer1->TimerLoad = timer_reload; |
| 264 | timer1->TimerValue = timer_reload; |
| 265 | timer1->TimerControl = timer_ctrl; |
| 266 | |
| 267 | /* |
| 268 | * Make irqs happen for the system timer |
| 269 | */ |
| 270 | setup_irq(IRQ_TIMERINT1, &integrator_timer_irq); |
| 271 | } |