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   1 /*
   2  * arch/arm/mach-ixp4xx/common.c
   3  *
   4  * Generic code shared across all IXP4XX platforms
   5  *
   6  * Maintainer: Deepak Saxena <dsaxena@plexity.net>
   7  *
   8  * Copyright 2002 (c) Intel Corporation
   9  * Copyright 2003-2004 (c) MontaVista, Software, Inc.
  10  *
  11  * This file is licensed under  the terms of the GNU General Public
  12  * License version 2. This program is licensed "as is" without any
  13  * warranty of any kind, whether express or implied.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/mm.h>
  18 #include <linux/init.h>
  19 #include <linux/serial.h>
  20 #include <linux/sched.h>
  21 #include <linux/tty.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/serial_core.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/bitops.h>
  27 #include <linux/time.h>
  28 #include <linux/timex.h>
  29 #include <linux/clocksource.h>
  30
  31 #include <asm/hardware.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/io.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/page.h>
  36 #include <asm/irq.h>
  37
  38 #include <asm/mach/map.h>
  39 #include <asm/mach/irq.h>
  40 #include <asm/mach/time.h>
  41
  42 /*************************************************************************
  43  * IXP4xx chipset I/O mapping
  44  *************************************************************************/
  45 static struct map_desc ixp4xx_io_desc[] __initdata = {
  46         {       /* UART, Interrupt ctrl, GPIO, timers, NPEs, MACs, USB .... */
  47                 .virtual        = IXP4XX_PERIPHERAL_BASE_VIRT,
  48                 .pfn            = __phys_to_pfn(IXP4XX_PERIPHERAL_BASE_PHYS),
  49                 .length         = IXP4XX_PERIPHERAL_REGION_SIZE,
  50                 .type           = MT_DEVICE
  51         }, {    /* Expansion Bus Config Registers */
  52                 .virtual        = IXP4XX_EXP_CFG_BASE_VIRT,
  53                 .pfn            = __phys_to_pfn(IXP4XX_EXP_CFG_BASE_PHYS),
  54                 .length         = IXP4XX_EXP_CFG_REGION_SIZE,
  55                 .type           = MT_DEVICE
  56         }, {    /* PCI Registers */
  57                 .virtual        = IXP4XX_PCI_CFG_BASE_VIRT,
  58                 .pfn            = __phys_to_pfn(IXP4XX_PCI_CFG_BASE_PHYS),
  59                 .length         = IXP4XX_PCI_CFG_REGION_SIZE,
  60                 .type           = MT_DEVICE
  61         },
  62 #ifdef CONFIG_DEBUG_LL
  63         {       /* Debug UART mapping */
  64                 .virtual        = IXP4XX_DEBUG_UART_BASE_VIRT,
  65                 .pfn            = __phys_to_pfn(IXP4XX_DEBUG_UART_BASE_PHYS),
  66                 .length         = IXP4XX_DEBUG_UART_REGION_SIZE,
  67                 .type           = MT_DEVICE
  68         }
  69 #endif
  70 };
  71
  72 void __init ixp4xx_map_io(void)
  73 {
  74         iotable_init(ixp4xx_io_desc, ARRAY_SIZE(ixp4xx_io_desc));
  75 }
  76
  77
  78 /*************************************************************************
  79  * IXP4xx chipset IRQ handling
  80  *
  81  * TODO: GPIO IRQs should be marked invalid until the user of the IRQ
  82  *       (be it PCI or something else) configures that GPIO line
  83  *       as an IRQ.
  84  **************************************************************************/
  85 enum ixp4xx_irq_type {
  86         IXP4XX_IRQ_LEVEL, IXP4XX_IRQ_EDGE
  87 };
  88
  89 /* Each bit represents an IRQ: 1: edge-triggered, 0: level triggered */
  90 static unsigned long long ixp4xx_irq_edge = 0;
  91
  92 /*
  93  * IRQ -> GPIO mapping table
  94  */
  95 static signed char irq2gpio[32] = {
  96         -1, -1, -1, -1, -1, -1,  0,  1,
  97         -1, -1, -1, -1, -1, -1, -1, -1,
  98         -1, -1, -1,  2,  3,  4,  5,  6,
  99          7,  8,  9, 10, 11, 12, -1, -1,
 100 };
 101
 102 static int ixp4xx_set_irq_type(unsigned int irq, unsigned int type)
 103 {
 104         int line = irq2gpio[irq];
 105         u32 int_style;
 106         enum ixp4xx_irq_type irq_type;
 107         volatile u32 *int_reg;
 108
 109         /*
 110          * Only for GPIO IRQs
 111          */
 112         if (line < 0)
 113                 return -EINVAL;
 114
 115         switch (type){
 116         case IRQT_BOTHEDGE:
 117                 int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
 118                 irq_type = IXP4XX_IRQ_EDGE;
 119                 break;
 120         case IRQT_RISING:
 121                 int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
 122                 irq_type = IXP4XX_IRQ_EDGE;
 123                 break;
 124         case IRQT_FALLING:
 125                 int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
 126                 irq_type = IXP4XX_IRQ_EDGE;
 127                 break;
 128         case IRQT_HIGH:
 129                 int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
 130                 irq_type = IXP4XX_IRQ_LEVEL;
 131                 break;
 132         case IRQT_LOW:
 133                 int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
 134                 irq_type = IXP4XX_IRQ_LEVEL;
 135                 break;
 136         default:
 137                 return -EINVAL;
 138         }
 139
 140         if (irq_type == IXP4XX_IRQ_EDGE)
 141                 ixp4xx_irq_edge |= (1 << irq);
 142         else
 143                 ixp4xx_irq_edge &= ~(1 << irq);
 144
 145         if (line >= 8) {        /* pins 8-15 */
 146                 line -= 8;
 147                 int_reg = IXP4XX_GPIO_GPIT2R;
 148         } else {                /* pins 0-7 */
 149                 int_reg = IXP4XX_GPIO_GPIT1R;
 150         }
 151
 152         /* Clear the style for the appropriate pin */
 153         *int_reg &= ~(IXP4XX_GPIO_STYLE_CLEAR <<
 154                         (line * IXP4XX_GPIO_STYLE_SIZE));
 155
 156         *IXP4XX_GPIO_GPISR = (1 << line);
 157
 158         /* Set the new style */
 159         *int_reg |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE));
 160
 161         /* Configure the line as an input */
 162         gpio_line_config(line, IXP4XX_GPIO_IN);
 163
 164         return 0;
 165 }
 166
 167 static void ixp4xx_irq_mask(unsigned int irq)
 168 {
 169         if (cpu_is_ixp46x() && irq >= 32)
 170                 *IXP4XX_ICMR2 &= ~(1 << (irq - 32));
 171         else
 172                 *IXP4XX_ICMR &= ~(1 << irq);
 173 }
 174
 175 static void ixp4xx_irq_ack(unsigned int irq)
 176 {
 177         int line = (irq < 32) ? irq2gpio[irq] : -1;
 178
 179         if (line >= 0)
 180                 *IXP4XX_GPIO_GPISR = (1 << line);
 181 }
 182
 183 /*
 184  * Level triggered interrupts on GPIO lines can only be cleared when the
 185  * interrupt condition disappears.
 186  */
 187 static void ixp4xx_irq_unmask(unsigned int irq)
 188 {
 189         if (!(ixp4xx_irq_edge & (1 << irq)))
 190                 ixp4xx_irq_ack(irq);
 191
 192         if (cpu_is_ixp46x() && irq >= 32)
 193                 *IXP4XX_ICMR2 |= (1 << (irq - 32));
 194         else
 195                 *IXP4XX_ICMR |= (1 << irq);
 196 }
 197
 198 static struct irqchip ixp4xx_irq_chip = {
 199         .name           = "IXP4xx",
 200         .ack            = ixp4xx_irq_ack,
 201         .mask           = ixp4xx_irq_mask,
 202         .unmask         = ixp4xx_irq_unmask,
 203         .set_type       = ixp4xx_set_irq_type,
 204 };
 205
 206 void __init ixp4xx_init_irq(void)
 207 {
 208         int i = 0;
 209
 210         /* Route all sources to IRQ instead of FIQ */
 211         *IXP4XX_ICLR = 0x0;
 212
 213         /* Disable all interrupt */
 214         *IXP4XX_ICMR = 0x0;
 215
 216         if (cpu_is_ixp46x()) {
 217                 /* Route upper 32 sources to IRQ instead of FIQ */
 218                 *IXP4XX_ICLR2 = 0x00;
 219
 220                 /* Disable upper 32 interrupts */
 221                 *IXP4XX_ICMR2 = 0x00;
 222         }
 223
 224         /* Default to all level triggered */
 225         for(i = 0; i < NR_IRQS; i++) {
 226                 set_irq_chip(i, &ixp4xx_irq_chip);
 227                 set_irq_handler(i, do_level_IRQ);
 228                 set_irq_flags(i, IRQF_VALID);
 229         }
 230 }
 231
 232
 233 /*************************************************************************
 234  * IXP4xx timer tick
 235  * We use OS timer1 on the CPU for the timer tick and the timestamp
 236  * counter as a source of real clock ticks to account for missed jiffies.
 237  *************************************************************************/
 238
 239 static unsigned volatile last_jiffy_time;
 240
 241 #define CLOCK_TICKS_PER_USEC    ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
 242
 243 static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id)
 244 {
 245         write_seqlock(&xtime_lock);
 246
 247         /* Clear Pending Interrupt by writing '1' to it */
 248         *IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 249
 250         /*
 251          * Catch up with the real idea of time
 252          */
 253         while ((signed long)(*IXP4XX_OSTS - last_jiffy_time) >= LATCH) {
 254                 timer_tick();
 255                 last_jiffy_time += LATCH;
 256         }
 257
 258         write_sequnlock(&xtime_lock);
 259
 260         return IRQ_HANDLED;
 261 }
 262
 263 static struct irqaction ixp4xx_timer_irq = {
 264         .name           = "IXP4xx Timer Tick",
 265         .flags          = IRQF_DISABLED | IRQF_TIMER,
 266         .handler        = ixp4xx_timer_interrupt,
 267 };
 268
 269 static void __init ixp4xx_timer_init(void)
 270 {
 271         /* Clear Pending Interrupt by writing '1' to it */
 272         *IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 273
 274         /* Setup the Timer counter value */
 275         *IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
 276
 277         /* Reset time-stamp counter */
 278         *IXP4XX_OSTS = 0;
 279         last_jiffy_time = 0;
 280
 281         /* Connect the interrupt handler and enable the interrupt */
 282         setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq);
 283 }
 284
 285 struct sys_timer ixp4xx_timer = {
 286         .init           = ixp4xx_timer_init,
 287 };
 288
 289 static struct resource ixp46x_i2c_resources[] = {
 290         [0] = {
 291                 .start  = 0xc8011000,
 292                 .end    = 0xc801101c,
 293                 .flags  = IORESOURCE_MEM,
 294         },
 295         [1] = {
 296                 .start  = IRQ_IXP4XX_I2C,
 297                 .end    = IRQ_IXP4XX_I2C,
 298                 .flags  = IORESOURCE_IRQ
 299         }
 300 };
 301
 302 /*
 303  * I2C controller. The IXP46x uses the same block as the IOP3xx, so
 304  * we just use the same device name.
 305  */
 306 static struct platform_device ixp46x_i2c_controller = {
 307         .name           = "IOP3xx-I2C",
 308         .id             = 0,
 309         .num_resources  = 2,
 310         .resource       = ixp46x_i2c_resources
 311 };
 312
 313 static struct platform_device *ixp46x_devices[] __initdata = {
 314         &ixp46x_i2c_controller
 315 };
 316
 317 unsigned long ixp4xx_exp_bus_size;
 318 EXPORT_SYMBOL(ixp4xx_exp_bus_size);
 319
 320 void __init ixp4xx_sys_init(void)
 321 {
 322         ixp4xx_exp_bus_size = SZ_16M;
 323
 324         if (cpu_is_ixp46x()) {
 325                 int region;
 326
 327                 platform_add_devices(ixp46x_devices,
 328                                 ARRAY_SIZE(ixp46x_devices));
 329
 330                 for (region = 0; region < 7; region++) {
 331                         if((*(IXP4XX_EXP_REG(0x4 * region)) & 0x200)) {
 332                                 ixp4xx_exp_bus_size = SZ_32M;
 333                                 break;
 334                         }
 335                 }
 336         }
 337
 338         printk("IXP4xx: Using %luMiB expansion bus window size\n",
 339                         ixp4xx_exp_bus_size >> 20);
 340 }
 341
 342 cycle_t ixp4xx_get_cycles(void)
 343 {
 344         return *IXP4XX_OSTS;
 345 }
 346
 347 static struct clocksource clocksource_ixp4xx = {
 348         .name           = "OSTS",
 349         .rating         = 200,
 350         .read           = ixp4xx_get_cycles,
 351         .mask           = CLOCKSOURCE_MASK(32),
 352         .shift          = 20,
 353         .is_continuous  = 1,
 354 };
 355
 356 unsigned long ixp4xx_timer_freq = FREQ;
 357 static int __init ixp4xx_clocksource_init(void)
 358 {
 359         clocksource_ixp4xx.mult =
 360                 clocksource_hz2mult(ixp4xx_timer_freq,
 361                                     clocksource_ixp4xx.shift);
 362         clocksource_register(&clocksource_ixp4xx);
 363
 364         return 0;
 365 }
 366
 367 device_initcall(ixp4xx_clocksource_init);