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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/config.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mm.h>
  19 #include <linux/init.h>
  20 #include <linux/serial.h>
  21 #include <linux/sched.h>
  22 #include <linux/tty.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/serial_core.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/bitops.h>
  28 #include <linux/time.h>
  29 #include <linux/timex.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 static void ixp4xx_config_irq(unsigned irq, enum ixp4xx_irq_type type);
  90
  91 /*
  92  * IRQ -> GPIO mapping table
  93  */
  94 static signed char irq2gpio[32] = {
  95         -1, -1, -1, -1, -1, -1,  0,  1,
  96         -1, -1, -1, -1, -1, -1, -1, -1,
  97         -1, -1, -1,  2,  3,  4,  5,  6,
  98          7,  8,  9, 10, 11, 12, -1, -1,
  99 };
 100
 101 static int ixp4xx_set_irq_type(unsigned int irq, unsigned int type)
 102 {
 103         int line = irq2gpio[irq];
 104         u32 int_style;
 105         enum ixp4xx_irq_type irq_type;
 106         volatile u32 *int_reg;
 107
 108         /*
 109          * Only for GPIO IRQs
 110          */
 111         if (line < 0)
 112                 return -EINVAL;
 113
 114         switch (type){
 115         case IRQT_BOTHEDGE:
 116                 int_style = IXP4XX_GPIO_STYLE_TRANSITIONAL;
 117                 irq_type = IXP4XX_IRQ_EDGE;
 118                 break;
 119         case IRQT_RISING:
 120                 int_style = IXP4XX_GPIO_STYLE_RISING_EDGE;
 121                 irq_type = IXP4XX_IRQ_EDGE;
 122                 break;
 123         case IRQT_FALLING:
 124                 int_style = IXP4XX_GPIO_STYLE_FALLING_EDGE;
 125                 irq_type = IXP4XX_IRQ_EDGE;
 126                 break;
 127         case IRQT_HIGH:
 128                 int_style = IXP4XX_GPIO_STYLE_ACTIVE_HIGH;
 129                 irq_type = IXP4XX_IRQ_LEVEL;
 130                 break;
 131         case IRQT_LOW:
 132                 int_style = IXP4XX_GPIO_STYLE_ACTIVE_LOW;
 133                 irq_type = IXP4XX_IRQ_LEVEL;
 134                 break;
 135         default:
 136                 return -EINVAL;
 137         }
 138         ixp4xx_config_irq(irq, irq_type);
 139
 140         if (line >= 8) {        /* pins 8-15 */
 141                 line -= 8;
 142                 int_reg = IXP4XX_GPIO_GPIT2R;
 143         } else {                /* pins 0-7 */
 144                 int_reg = IXP4XX_GPIO_GPIT1R;
 145         }
 146
 147         /* Clear the style for the appropriate pin */
 148         *int_reg &= ~(IXP4XX_GPIO_STYLE_CLEAR <<
 149                         (line * IXP4XX_GPIO_STYLE_SIZE));
 150
 151         *IXP4XX_GPIO_GPISR = (1 << line);
 152
 153         /* Set the new style */
 154         *int_reg |= (int_style << (line * IXP4XX_GPIO_STYLE_SIZE));
 155
 156         /* Configure the line as an input */
 157         gpio_line_config(line, IXP4XX_GPIO_IN);
 158
 159         return 0;
 160 }
 161
 162 static void ixp4xx_irq_mask(unsigned int irq)
 163 {
 164         if (cpu_is_ixp46x() && irq >= 32)
 165                 *IXP4XX_ICMR2 &= ~(1 << (irq - 32));
 166         else
 167                 *IXP4XX_ICMR &= ~(1 << irq);
 168 }
 169
 170 static void ixp4xx_irq_unmask(unsigned int irq)
 171 {
 172         if (cpu_is_ixp46x() && irq >= 32)
 173                 *IXP4XX_ICMR2 |= (1 << (irq - 32));
 174         else
 175                 *IXP4XX_ICMR |= (1 << irq);
 176 }
 177
 178 static void ixp4xx_irq_ack(unsigned int irq)
 179 {
 180         int line = (irq < 32) ? irq2gpio[irq] : -1;
 181
 182         if (line >= 0)
 183                 *IXP4XX_GPIO_GPISR = (1 << line);
 184 }
 185
 186 /*
 187  * Level triggered interrupts on GPIO lines can only be cleared when the
 188  * interrupt condition disappears.
 189  */
 190 static void ixp4xx_irq_level_unmask(unsigned int irq)
 191 {
 192         ixp4xx_irq_ack(irq);
 193         ixp4xx_irq_unmask(irq);
 194 }
 195
 196 static struct irqchip ixp4xx_irq_level_chip = {
 197         .ack            = ixp4xx_irq_mask,
 198         .mask           = ixp4xx_irq_mask,
 199         .unmask         = ixp4xx_irq_level_unmask,
 200         .set_type       = ixp4xx_set_irq_type,
 201 };
 202
 203 static struct irqchip ixp4xx_irq_edge_chip = {
 204         .ack            = ixp4xx_irq_ack,
 205         .mask           = ixp4xx_irq_mask,
 206         .unmask         = ixp4xx_irq_unmask,
 207         .set_type       = ixp4xx_set_irq_type,
 208 };
 209
 210 static void ixp4xx_config_irq(unsigned irq, enum ixp4xx_irq_type type)
 211 {
 212         switch (type) {
 213         case IXP4XX_IRQ_LEVEL:
 214                 set_irq_chip(irq, &ixp4xx_irq_level_chip);
 215                 set_irq_handler(irq, do_level_IRQ);
 216                 break;
 217         case IXP4XX_IRQ_EDGE:
 218                 set_irq_chip(irq, &ixp4xx_irq_edge_chip);
 219                 set_irq_handler(irq, do_edge_IRQ);
 220                 break;
 221         }
 222         set_irq_flags(irq, IRQF_VALID);
 223 }
 224
 225 void __init ixp4xx_init_irq(void)
 226 {
 227         int i = 0;
 228
 229         /* Route all sources to IRQ instead of FIQ */
 230         *IXP4XX_ICLR = 0x0;
 231
 232         /* Disable all interrupt */
 233         *IXP4XX_ICMR = 0x0;
 234
 235         if (cpu_is_ixp46x()) {
 236                 /* Route upper 32 sources to IRQ instead of FIQ */
 237                 *IXP4XX_ICLR2 = 0x00;
 238
 239                 /* Disable upper 32 interrupts */
 240                 *IXP4XX_ICMR2 = 0x00;
 241         }
 242
 243         /* Default to all level triggered */
 244         for(i = 0; i < NR_IRQS; i++)
 245                 ixp4xx_config_irq(i, IXP4XX_IRQ_LEVEL);
 246 }
 247
 248
 249 /*************************************************************************
 250  * IXP4xx timer tick
 251  * We use OS timer1 on the CPU for the timer tick and the timestamp
 252  * counter as a source of real clock ticks to account for missed jiffies.
 253  *************************************************************************/
 254
 255 static unsigned volatile last_jiffy_time;
 256
 257 #define CLOCK_TICKS_PER_USEC    ((CLOCK_TICK_RATE + USEC_PER_SEC/2) / USEC_PER_SEC)
 258
 259 /* IRQs are disabled before entering here from do_gettimeofday() */
 260 static unsigned long ixp4xx_gettimeoffset(void)
 261 {
 262         u32 elapsed;
 263
 264         elapsed = *IXP4XX_OSTS - last_jiffy_time;
 265
 266         return elapsed / CLOCK_TICKS_PER_USEC;
 267 }
 268
 269 static irqreturn_t ixp4xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 270 {
 271         write_seqlock(&xtime_lock);
 272
 273         /* Clear Pending Interrupt by writing '1' to it */
 274         *IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 275
 276         /*
 277          * Catch up with the real idea of time
 278          */
 279         while ((signed long)(*IXP4XX_OSTS - last_jiffy_time) >= LATCH) {
 280                 timer_tick(regs);
 281                 last_jiffy_time += LATCH;
 282         }
 283
 284         write_sequnlock(&xtime_lock);
 285
 286         return IRQ_HANDLED;
 287 }
 288
 289 static struct irqaction ixp4xx_timer_irq = {
 290         .name           = "IXP4xx Timer Tick",
 291         .flags          = SA_INTERRUPT | SA_TIMER,
 292         .handler        = ixp4xx_timer_interrupt,
 293 };
 294
 295 static void __init ixp4xx_timer_init(void)
 296 {
 297         /* Clear Pending Interrupt by writing '1' to it */
 298         *IXP4XX_OSST = IXP4XX_OSST_TIMER_1_PEND;
 299
 300         /* Setup the Timer counter value */
 301         *IXP4XX_OSRT1 = (LATCH & ~IXP4XX_OST_RELOAD_MASK) | IXP4XX_OST_ENABLE;
 302
 303         /* Reset time-stamp counter */
 304         *IXP4XX_OSTS = 0;
 305         last_jiffy_time = 0;
 306
 307         /* Connect the interrupt handler and enable the interrupt */
 308         setup_irq(IRQ_IXP4XX_TIMER1, &ixp4xx_timer_irq);
 309 }
 310
 311 struct sys_timer ixp4xx_timer = {
 312         .init           = ixp4xx_timer_init,
 313         .offset         = ixp4xx_gettimeoffset,
 314 };
 315
 316 static struct resource ixp46x_i2c_resources[] = {
 317         [0] = {
 318                 .start  = 0xc8011000,
 319                 .end    = 0xc801101c,
 320                 .flags  = IORESOURCE_MEM,
 321         },
 322         [1] = {
 323                 .start  = IRQ_IXP4XX_I2C,
 324                 .end    = IRQ_IXP4XX_I2C,
 325                 .flags  = IORESOURCE_IRQ
 326         }
 327 };
 328
 329 /*
 330  * I2C controller. The IXP46x uses the same block as the IOP3xx, so
 331  * we just use the same device name.
 332  */
 333 static struct platform_device ixp46x_i2c_controller = {
 334         .name           = "IOP3xx-I2C",
 335         .id             = 0,
 336         .num_resources  = 2,
 337         .resource       = ixp46x_i2c_resources
 338 };
 339
 340 static struct platform_device *ixp46x_devices[] __initdata = {
 341         &ixp46x_i2c_controller
 342 };
 343
 344 unsigned long ixp4xx_exp_bus_size;
 345 EXPORT_SYMBOL(ixp4xx_exp_bus_size);
 346
 347 void __init ixp4xx_sys_init(void)
 348 {
 349         ixp4xx_exp_bus_size = SZ_16M;
 350
 351         if (cpu_is_ixp46x()) {
 352                 int region;
 353
 354                 platform_add_devices(ixp46x_devices,
 355                                 ARRAY_SIZE(ixp46x_devices));
 356
 357                 for (region = 0; region < 7; region++) {
 358                         if((*(IXP4XX_EXP_REG(0x4 * region)) & 0x200)) {
 359                                 ixp4xx_exp_bus_size = SZ_32M;
 360                                 break;
 361                         }
 362                 }
 363         }
 364
 365         printk("IXP4xx: Using %luMiB expansion bus window size\n",
 366                         ixp4xx_exp_bus_size >> 20);
 367 }
 368