/* * arch/arm/mach-ep93xx/core.c * Core routines for Cirrus EP93xx chips. * * Copyright (C) 2006 Lennert Buytenhek * * Thanks go to Michael Burian and Ray Lehtiniemi for their key * role in the ep93xx linux community. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /************************************************************************* * Static I/O mappings that are needed for all EP93xx platforms *************************************************************************/ static struct map_desc ep93xx_io_desc[] __initdata = { { .virtual = EP93XX_AHB_VIRT_BASE, .pfn = __phys_to_pfn(EP93XX_AHB_PHYS_BASE), .length = EP93XX_AHB_SIZE, .type = MT_DEVICE, }, { .virtual = EP93XX_APB_VIRT_BASE, .pfn = __phys_to_pfn(EP93XX_APB_PHYS_BASE), .length = EP93XX_APB_SIZE, .type = MT_DEVICE, }, }; void __init ep93xx_map_io(void) { iotable_init(ep93xx_io_desc, ARRAY_SIZE(ep93xx_io_desc)); } /************************************************************************* * Timer handling for EP93xx ************************************************************************* * The ep93xx has four internal timers. Timers 1, 2 (both 16 bit) and * 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate * an interrupt on underflow. Timer 4 (40 bit) counts down at 983.04 kHz, * is free-running, and can't generate interrupts. * * The 508 kHz timers are ideal for use for the timer interrupt, as the * most common values of HZ divide 508 kHz nicely. We pick one of the 16 * bit timers (timer 1) since we don't need more than 16 bits of reload * value as long as HZ >= 8. * * The higher clock rate of timer 4 makes it a better choice than the * other timers for use in gettimeoffset(), while the fact that it can't * generate interrupts means we don't have to worry about not being able * to use this timer for something else. We also use timer 4 for keeping * track of lost jiffies. */ static unsigned int last_jiffy_time; #define TIMER4_TICKS_PER_JIFFY ((CLOCK_TICK_RATE + (HZ/2)) / HZ) static int ep93xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { write_seqlock(&xtime_lock); __raw_writel(1, EP93XX_TIMER1_CLEAR); while (__raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time >= TIMER4_TICKS_PER_JIFFY) { last_jiffy_time += TIMER4_TICKS_PER_JIFFY; timer_tick(regs); } write_sequnlock(&xtime_lock); return IRQ_HANDLED; } static struct irqaction ep93xx_timer_irq = { .name = "ep93xx timer", .flags = SA_INTERRUPT | SA_TIMER, .handler = ep93xx_timer_interrupt, }; static void __init ep93xx_timer_init(void) { /* Enable periodic HZ timer. */ __raw_writel(0x48, EP93XX_TIMER1_CONTROL); __raw_writel((508000 / HZ) - 1, EP93XX_TIMER1_LOAD); __raw_writel(0xc8, EP93XX_TIMER1_CONTROL); /* Enable lost jiffy timer. */ __raw_writel(0x100, EP93XX_TIMER4_VALUE_HIGH); setup_irq(IRQ_EP93XX_TIMER1, &ep93xx_timer_irq); } static unsigned long ep93xx_gettimeoffset(void) { int offset; offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time; /* Calculate (1000000 / 983040) * offset. */ return offset + (53 * offset / 3072); } struct sys_timer ep93xx_timer = { .init = ep93xx_timer_init, .offset = ep93xx_gettimeoffset, }; /************************************************************************* * GPIO handling for EP93xx *************************************************************************/ static unsigned char data_register_offset[8] = { 0x00, 0x04, 0x08, 0x0c, 0x20, 0x30, 0x38, 0x40, }; static unsigned char data_direction_register_offset[8] = { 0x10, 0x14, 0x18, 0x1c, 0x24, 0x34, 0x3c, 0x44, }; void gpio_line_config(int line, int direction) { unsigned int data_direction_register; unsigned long flags; unsigned char v; data_direction_register = EP93XX_GPIO_REG(data_direction_register_offset[line >> 3]); local_irq_save(flags); if (direction == GPIO_OUT) { v = __raw_readb(data_direction_register); v |= 1 << (line & 7); __raw_writeb(v, data_direction_register); } else if (direction == GPIO_IN) { v = __raw_readb(data_direction_register); v &= ~(1 << (line & 7)); __raw_writeb(v, data_direction_register); } local_irq_restore(flags); } EXPORT_SYMBOL(gpio_line_config); int gpio_line_get(int line) { unsigned int data_register; data_register = EP93XX_GPIO_REG(data_register_offset[line >> 3]); return !!(__raw_readb(data_register) & (1 << (line & 7))); } EXPORT_SYMBOL(gpio_line_get); void gpio_line_set(int line, int value) { unsigned int data_register; unsigned long flags; unsigned char v; data_register = EP93XX_GPIO_REG(data_register_offset[line >> 3]); local_irq_save(flags); if (value == EP93XX_GPIO_HIGH) { v = __raw_readb(data_register); v |= 1 << (line & 7); __raw_writeb(v, data_register); } else if (value == EP93XX_GPIO_LOW) { v = __raw_readb(data_register); v &= ~(1 << (line & 7)); __raw_writeb(v, data_register); } local_irq_restore(flags); } EXPORT_SYMBOL(gpio_line_set); /************************************************************************* * EP93xx IRQ handling *************************************************************************/ void __init ep93xx_init_irq(void) { vic_init((void *)EP93XX_VIC1_BASE, 0, EP93XX_VIC1_VALID_IRQ_MASK); vic_init((void *)EP93XX_VIC2_BASE, 32, EP93XX_VIC2_VALID_IRQ_MASK); } /************************************************************************* * EP93xx peripheral handling *************************************************************************/ void __init ep93xx_init_devices(void) { unsigned int v; /* * Disallow access to MaverickCrunch initially. */ v = __raw_readl(EP93XX_SYSCON_DEVICE_CONFIG); v &= ~EP93XX_SYSCON_DEVICE_CONFIG_CRUNCH_ENABLE; __raw_writel(0xaa, EP93XX_SYSCON_SWLOCK); __raw_writel(v, EP93XX_SYSCON_DEVICE_CONFIG); }