diff options
Diffstat (limited to 'arch/mips/sni/rm200.c')
| -rw-r--r-- | arch/mips/sni/rm200.c | 326 |
1 files changed, 314 insertions, 12 deletions
diff --git a/arch/mips/sni/rm200.c b/arch/mips/sni/rm200.c index 67b061eef6cd..5310aa75afa4 100644 --- a/arch/mips/sni/rm200.c +++ b/arch/mips/sni/rm200.c @@ -5,30 +5,36 @@ * License. See the file "COPYING" in the main directory of this archive * for more details. * - * Copyright (C) 2006 Thomas Bogendoerfer (tsbogend@alpha.franken.de) + * Copyright (C) 2006,2007 Thomas Bogendoerfer (tsbogend@alpha.franken.de) + * + * i8259 parts ripped out of arch/mips/kernel/i8259.c */ +#include <linux/delay.h> #include <linux/init.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/serial_8250.h> +#include <linux/io.h> #include <asm/sni.h> #include <asm/time.h> #include <asm/irq_cpu.h> -#define PORT(_base,_irq) \ +#define RM200_I8259A_IRQ_BASE 32 + +#define MEMPORT(_base,_irq) \ { \ - .iobase = _base, \ + .mapbase = _base, \ .irq = _irq, \ .uartclk = 1843200, \ - .iotype = UPIO_PORT, \ - .flags = UPF_BOOT_AUTOCONF, \ + .iotype = UPIO_MEM, \ + .flags = UPF_BOOT_AUTOCONF|UPF_IOREMAP, \ } static struct plat_serial8250_port rm200_data[] = { - PORT(0x3f8, 4), - PORT(0x2f8, 3), + MEMPORT(0x160003f8, RM200_I8259A_IRQ_BASE + 4), + MEMPORT(0x160002f8, RM200_I8259A_IRQ_BASE + 3), { }, }; @@ -112,15 +118,311 @@ static int __init snirm_setup_devinit(void) platform_device_register(&rm200_ds1216_device); platform_device_register(&snirm_82596_rm200_pdev); platform_device_register(&snirm_53c710_rm200_pdev); + sni_eisa_root_init(); } return 0; } device_initcall(snirm_setup_devinit); +/* + * RM200 has an ISA and an EISA bus. The iSA bus is only used + * for onboard devices and also has twi i8259 PICs. Since these + * PICs are no accessible via inb/outb the following code uses + * readb/writeb to access them + */ + +DEFINE_SPINLOCK(sni_rm200_i8259A_lock); +#define PIC_CMD 0x00 +#define PIC_IMR 0x01 +#define PIC_ISR PIC_CMD +#define PIC_POLL PIC_ISR +#define PIC_OCW3 PIC_ISR + +/* i8259A PIC related value */ +#define PIC_CASCADE_IR 2 +#define MASTER_ICW4_DEFAULT 0x01 +#define SLAVE_ICW4_DEFAULT 0x01 + +/* + * This contains the irq mask for both 8259A irq controllers, + */ +static unsigned int rm200_cached_irq_mask = 0xffff; +static __iomem u8 *rm200_pic_master; +static __iomem u8 *rm200_pic_slave; + +#define cached_master_mask (rm200_cached_irq_mask) +#define cached_slave_mask (rm200_cached_irq_mask >> 8) + +static void sni_rm200_disable_8259A_irq(unsigned int irq) +{ + unsigned int mask; + unsigned long flags; + + irq -= RM200_I8259A_IRQ_BASE; + mask = 1 << irq; + spin_lock_irqsave(&sni_rm200_i8259A_lock, flags); + rm200_cached_irq_mask |= mask; + if (irq & 8) + writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR); + else + writeb(cached_master_mask, rm200_pic_master + PIC_IMR); + spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags); +} + +static void sni_rm200_enable_8259A_irq(unsigned int irq) +{ + unsigned int mask; + unsigned long flags; + + irq -= RM200_I8259A_IRQ_BASE; + mask = ~(1 << irq); + spin_lock_irqsave(&sni_rm200_i8259A_lock, flags); + rm200_cached_irq_mask &= mask; + if (irq & 8) + writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR); + else + writeb(cached_master_mask, rm200_pic_master + PIC_IMR); + spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags); +} + +static inline int sni_rm200_i8259A_irq_real(unsigned int irq) +{ + int value; + int irqmask = 1 << irq; + + if (irq < 8) { + writeb(0x0B, rm200_pic_master + PIC_CMD); + value = readb(rm200_pic_master + PIC_CMD) & irqmask; + writeb(0x0A, rm200_pic_master + PIC_CMD); + return value; + } + writeb(0x0B, rm200_pic_slave + PIC_CMD); /* ISR register */ + value = readb(rm200_pic_slave + PIC_CMD) & (irqmask >> 8); + writeb(0x0A, rm200_pic_slave + PIC_CMD); + return value; +} + +/* + * Careful! The 8259A is a fragile beast, it pretty + * much _has_ to be done exactly like this (mask it + * first, _then_ send the EOI, and the order of EOI + * to the two 8259s is important! + */ +void sni_rm200_mask_and_ack_8259A(unsigned int irq) +{ + unsigned int irqmask; + unsigned long flags; + + irq -= RM200_I8259A_IRQ_BASE; + irqmask = 1 << irq; + spin_lock_irqsave(&sni_rm200_i8259A_lock, flags); + /* + * Lightweight spurious IRQ detection. We do not want + * to overdo spurious IRQ handling - it's usually a sign + * of hardware problems, so we only do the checks we can + * do without slowing down good hardware unnecessarily. + * + * Note that IRQ7 and IRQ15 (the two spurious IRQs + * usually resulting from the 8259A-1|2 PICs) occur + * even if the IRQ is masked in the 8259A. Thus we + * can check spurious 8259A IRQs without doing the + * quite slow i8259A_irq_real() call for every IRQ. + * This does not cover 100% of spurious interrupts, + * but should be enough to warn the user that there + * is something bad going on ... + */ + if (rm200_cached_irq_mask & irqmask) + goto spurious_8259A_irq; + rm200_cached_irq_mask |= irqmask; + +handle_real_irq: + if (irq & 8) { + readb(rm200_pic_slave + PIC_IMR); + writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR); + writeb(0x60+(irq & 7), rm200_pic_slave + PIC_CMD); + writeb(0x60+PIC_CASCADE_IR, rm200_pic_master + PIC_CMD); + } else { + readb(rm200_pic_master + PIC_IMR); + writeb(cached_master_mask, rm200_pic_master + PIC_IMR); + writeb(0x60+irq, rm200_pic_master + PIC_CMD); + } + spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags); + return; + +spurious_8259A_irq: + /* + * this is the slow path - should happen rarely. + */ + if (sni_rm200_i8259A_irq_real(irq)) + /* + * oops, the IRQ _is_ in service according to the + * 8259A - not spurious, go handle it. + */ + goto handle_real_irq; + + { + static int spurious_irq_mask; + /* + * At this point we can be sure the IRQ is spurious, + * lets ACK and report it. [once per IRQ] + */ + if (!(spurious_irq_mask & irqmask)) { + printk(KERN_DEBUG + "spurious RM200 8259A interrupt: IRQ%d.\n", irq); + spurious_irq_mask |= irqmask; + } + atomic_inc(&irq_err_count); + /* + * Theoretically we do not have to handle this IRQ, + * but in Linux this does not cause problems and is + * simpler for us. + */ + goto handle_real_irq; + } +} + +static struct irq_chip sni_rm200_i8259A_chip = { + .name = "RM200-XT-PIC", + .mask = sni_rm200_disable_8259A_irq, + .unmask = sni_rm200_enable_8259A_irq, + .mask_ack = sni_rm200_mask_and_ack_8259A, +}; + +/* + * Do the traditional i8259 interrupt polling thing. This is for the few + * cases where no better interrupt acknowledge method is available and we + * absolutely must touch the i8259. + */ +static inline int sni_rm200_i8259_irq(void) +{ + int irq; + + spin_lock(&sni_rm200_i8259A_lock); + + /* Perform an interrupt acknowledge cycle on controller 1. */ + writeb(0x0C, rm200_pic_master + PIC_CMD); /* prepare for poll */ + irq = readb(rm200_pic_master + PIC_CMD) & 7; + if (irq == PIC_CASCADE_IR) { + /* + * Interrupt is cascaded so perform interrupt + * acknowledge on controller 2. + */ + writeb(0x0C, rm200_pic_slave + PIC_CMD); /* prepare for poll */ + irq = (readb(rm200_pic_slave + PIC_CMD) & 7) + 8; + } + + if (unlikely(irq == 7)) { + /* + * This may be a spurious interrupt. + * + * Read the interrupt status register (ISR). If the most + * significant bit is not set then there is no valid + * interrupt. + */ + writeb(0x0B, rm200_pic_master + PIC_ISR); /* ISR register */ + if (~readb(rm200_pic_master + PIC_ISR) & 0x80) + irq = -1; + } + + spin_unlock(&sni_rm200_i8259A_lock); + + return likely(irq >= 0) ? irq + RM200_I8259A_IRQ_BASE : irq; +} + +void sni_rm200_init_8259A(void) +{ + unsigned long flags; + + spin_lock_irqsave(&sni_rm200_i8259A_lock, flags); + + writeb(0xff, rm200_pic_master + PIC_IMR); + writeb(0xff, rm200_pic_slave + PIC_IMR); + + writeb(0x11, rm200_pic_master + PIC_CMD); + writeb(0, rm200_pic_master + PIC_IMR); + writeb(1U << PIC_CASCADE_IR, rm200_pic_master + PIC_IMR); + writeb(MASTER_ICW4_DEFAULT, rm200_pic_master + PIC_IMR); + writeb(0x11, rm200_pic_slave + PIC_CMD); + writeb(8, rm200_pic_slave + PIC_IMR); + writeb(PIC_CASCADE_IR, rm200_pic_slave + PIC_IMR); + writeb(SLAVE_ICW4_DEFAULT, rm200_pic_slave + PIC_IMR); + udelay(100); /* wait for 8259A to initialize */ + + writeb(cached_master_mask, rm200_pic_master + PIC_IMR); + writeb(cached_slave_mask, rm200_pic_slave + PIC_IMR); + + spin_unlock_irqrestore(&sni_rm200_i8259A_lock, flags); +} + +/* + * IRQ2 is cascade interrupt to second interrupt controller + */ +static struct irqaction sni_rm200_irq2 = { + no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL +}; + +static struct resource sni_rm200_pic1_resource = { + .name = "onboard ISA pic1", + .start = 0x16000020, + .end = 0x16000023, + .flags = IORESOURCE_BUSY +}; + +static struct resource sni_rm200_pic2_resource = { + .name = "onboard ISA pic2", + .start = 0x160000a0, + .end = 0x160000a3, + .flags = IORESOURCE_BUSY +}; + +/* ISA irq handler */ +static irqreturn_t sni_rm200_i8259A_irq_handler(int dummy, void *p) +{ + int irq; + + irq = sni_rm200_i8259_irq(); + if (unlikely(irq < 0)) + return IRQ_NONE; + + do_IRQ(irq); + return IRQ_HANDLED; +} + +struct irqaction sni_rm200_i8259A_irq = { + .handler = sni_rm200_i8259A_irq_handler, + .name = "onboard ISA", + .flags = IRQF_SHARED +}; + +void __init sni_rm200_i8259_irqs(void) +{ + int i; + + rm200_pic_master = ioremap_nocache(0x16000020, 4); + if (!rm200_pic_master) + return; + rm200_pic_slave = ioremap_nocache(0x160000a0, 4); + if (!rm200_pic_master) { + iounmap(rm200_pic_master); + return; + } + + insert_resource(&iomem_resource, &sni_rm200_pic1_resource); + insert_resource(&iomem_resource, &sni_rm200_pic2_resource); + + sni_rm200_init_8259A(); + + for (i = RM200_I8259A_IRQ_BASE; i < RM200_I8259A_IRQ_BASE + 16; i++) + set_irq_chip_and_handler(i, &sni_rm200_i8259A_chip, + handle_level_irq); + + setup_irq(RM200_I8259A_IRQ_BASE + PIC_CASCADE_IR, &sni_rm200_irq2); +} + -#define SNI_RM200_INT_STAT_REG 0xbc000000 -#define SNI_RM200_INT_ENA_REG 0xbc080000 +#define SNI_RM200_INT_STAT_REG CKSEG1ADDR(0xbc000000) +#define SNI_RM200_INT_ENA_REG CKSEG1ADDR(0xbc080000) #define SNI_RM200_INT_START 24 #define SNI_RM200_INT_END 28 @@ -181,17 +483,17 @@ void __init sni_rm200_irq_init(void) * (volatile u8 *)SNI_RM200_INT_ENA_REG = 0x1f; + sni_rm200_i8259_irqs(); mips_cpu_irq_init(); /* Actually we've got more interrupts to handle ... */ for (i = SNI_RM200_INT_START; i <= SNI_RM200_INT_END; i++) set_irq_chip(i, &rm200_irq_type); sni_hwint = sni_rm200_hwint; change_c0_status(ST0_IM, IE_IRQ0); - setup_irq(SNI_RM200_INT_START + 0, &sni_isa_irq); + setup_irq(SNI_RM200_INT_START + 0, &sni_rm200_i8259A_irq); + setup_irq(SNI_RM200_INT_START + 1, &sni_isa_irq); } void __init sni_rm200_init(void) { - set_io_port_base(SNI_PORT_BASE + 0x02000000); - ioport_resource.end += 0x02000000; } |
