Logo Search packages:      
Sourcecode: linux version File versions  Download package

irq-uart.c

/* arch/arm/plat-samsung/irq-uart.c
 *    originally part of arch/arm/plat-s3c64xx/irq.c
 *
 * Copyright 2008 Openmoko, Inc.
 * Copyright 2008 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      http://armlinux.simtec.co.uk/
 *
 * Samsung- UART Interrupt handling
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/serial_core.h>
#include <linux/irq.h>
#include <linux/io.h>

#include <mach/map.h>
#include <plat/irq-uart.h>
#include <plat/regs-serial.h>
#include <plat/cpu.h>

/* Note, we make use of the fact that the parent IRQs, IRQ_UART[0..3]
 * are consecutive when looking up the interrupt in the demux routines.
 */

static inline void __iomem *s3c_irq_uart_base(struct irq_data *data)
{
      struct s3c_uart_irq *uirq = irq_data_get_irq_chip_data(data);
      return uirq->regs;
}

static inline unsigned int s3c_irq_uart_bit(unsigned int irq)
{
      return irq & 3;
}

static void s3c_irq_uart_mask(struct irq_data *data)
{
      void __iomem *regs = s3c_irq_uart_base(data);
      unsigned int bit = s3c_irq_uart_bit(data->irq);
      u32 reg;

      reg = __raw_readl(regs + S3C64XX_UINTM);
      reg |= (1 << bit);
      __raw_writel(reg, regs + S3C64XX_UINTM);
}

static void s3c_irq_uart_maskack(struct irq_data *data)
{
      void __iomem *regs = s3c_irq_uart_base(data);
      unsigned int bit = s3c_irq_uart_bit(data->irq);
      u32 reg;

      reg = __raw_readl(regs + S3C64XX_UINTM);
      reg |= (1 << bit);
      __raw_writel(reg, regs + S3C64XX_UINTM);
      __raw_writel(1 << bit, regs + S3C64XX_UINTP);
}

static void s3c_irq_uart_unmask(struct irq_data *data)
{
      void __iomem *regs = s3c_irq_uart_base(data);
      unsigned int bit = s3c_irq_uart_bit(data->irq);
      u32 reg;

      reg = __raw_readl(regs + S3C64XX_UINTM);
      reg &= ~(1 << bit);
      __raw_writel(reg, regs + S3C64XX_UINTM);
}

static void s3c_irq_uart_ack(struct irq_data *data)
{
      void __iomem *regs = s3c_irq_uart_base(data);
      unsigned int bit = s3c_irq_uart_bit(data->irq);

      __raw_writel(1 << bit, regs + S3C64XX_UINTP);
}

static void s3c_irq_demux_uart(unsigned int irq, struct irq_desc *desc)
{
      struct s3c_uart_irq *uirq = desc->irq_data.handler_data;
      u32 pend = __raw_readl(uirq->regs + S3C64XX_UINTP);
      int base = uirq->base_irq;

      if (pend & (1 << 0))
            generic_handle_irq(base);
      if (pend & (1 << 1))
            generic_handle_irq(base + 1);
      if (pend & (1 << 2))
            generic_handle_irq(base + 2);
      if (pend & (1 << 3))
            generic_handle_irq(base + 3);
}

static struct irq_chip s3c_irq_uart = {
      .name       = "s3c-uart",
      .irq_mask   = s3c_irq_uart_mask,
      .irq_unmask = s3c_irq_uart_unmask,
      .irq_mask_ack     = s3c_irq_uart_maskack,
      .irq_ack    = s3c_irq_uart_ack,
};

static void __init s3c_init_uart_irq(struct s3c_uart_irq *uirq)
{
      struct irq_desc *desc = irq_to_desc(uirq->parent_irq);
      void __iomem *reg_base = uirq->regs;
      unsigned int irq;
      int offs;

      /* mask all interrupts at the start. */
      __raw_writel(0xf, reg_base + S3C64XX_UINTM);

      for (offs = 0; offs < 3; offs++) {
            irq = uirq->base_irq + offs;

            set_irq_chip(irq, &s3c_irq_uart);
            set_irq_chip_data(irq, uirq);
            set_irq_handler(irq, handle_level_irq);
            set_irq_flags(irq, IRQF_VALID);
      }

      desc->irq_data.handler_data = uirq;
      set_irq_chained_handler(uirq->parent_irq, s3c_irq_demux_uart);
}

/**
 * s3c_init_uart_irqs() - initialise UART IRQs and the necessary demuxing
 * @irq: The interrupt data for registering
 * @nr_irqs: The number of interrupt descriptions in @irq.
 *
 * Register the UART interrupts specified by @irq including the demuxing
 * routines. This supports the S3C6400 and newer style of devices.
 */
void __init s3c_init_uart_irqs(struct s3c_uart_irq *irq, unsigned int nr_irqs)
{
      for (; nr_irqs > 0; nr_irqs--, irq++)
            s3c_init_uart_irq(irq);
}

Generated by  Doxygen 1.6.0   Back to index