diff options
Diffstat (limited to 'arch/mips/alchemy/devboards/bcsr.c')
| -rw-r--r-- | arch/mips/alchemy/devboards/bcsr.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/arch/mips/alchemy/devboards/bcsr.c b/arch/mips/alchemy/devboards/bcsr.c new file mode 100644 index 0000000..3bc4fd2 --- /dev/null +++ b/arch/mips/alchemy/devboards/bcsr.c @@ -0,0 +1,148 @@ +/* + * bcsr.h -- Db1xxx/Pb1xxx Devboard CPLD registers ("BCSR") abstraction. + * + * All Alchemy development boards (except, of course, the weird PB1000) + * have a few registers in a CPLD with standardised layout; they mostly + * only differ in base address. + * All registers are 16bits wide with 32bit spacing. + */ + +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <asm/addrspace.h> +#include <asm/io.h> +#include <asm/mach-db1x00/bcsr.h> + +static struct bcsr_reg { + void __iomem *raddr; + spinlock_t lock; +} bcsr_regs[BCSR_CNT]; + +static void __iomem *bcsr_virt; /* KSEG1 addr of BCSR base */ +static int bcsr_csc_base; /* linux-irq of first cascaded irq */ + +void __init bcsr_init(unsigned long bcsr1_phys, unsigned long bcsr2_phys) +{ + int i; + + bcsr1_phys = KSEG1ADDR(CPHYSADDR(bcsr1_phys)); + bcsr2_phys = KSEG1ADDR(CPHYSADDR(bcsr2_phys)); + + bcsr_virt = (void __iomem *)bcsr1_phys; + + for (i = 0; i < BCSR_CNT; i++) { + if (i >= BCSR_HEXLEDS) + bcsr_regs[i].raddr = (void __iomem *)bcsr2_phys + + (0x04 * (i - BCSR_HEXLEDS)); + else + bcsr_regs[i].raddr = (void __iomem *)bcsr1_phys + + (0x04 * i); + + spin_lock_init(&bcsr_regs[i].lock); + } +} + +unsigned short bcsr_read(enum bcsr_id reg) +{ + unsigned short r; + unsigned long flags; + + spin_lock_irqsave(&bcsr_regs[reg].lock, flags); + r = __raw_readw(bcsr_regs[reg].raddr); + spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags); + return r; +} +EXPORT_SYMBOL_GPL(bcsr_read); + +void bcsr_write(enum bcsr_id reg, unsigned short val) +{ + unsigned long flags; + + spin_lock_irqsave(&bcsr_regs[reg].lock, flags); + __raw_writew(val, bcsr_regs[reg].raddr); + wmb(); + spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags); +} +EXPORT_SYMBOL_GPL(bcsr_write); + +void bcsr_mod(enum bcsr_id reg, unsigned short clr, unsigned short set) +{ + unsigned short r; + unsigned long flags; + + spin_lock_irqsave(&bcsr_regs[reg].lock, flags); + r = __raw_readw(bcsr_regs[reg].raddr); + r &= ~clr; + r |= set; + __raw_writew(r, bcsr_regs[reg].raddr); + wmb(); + spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags); +} +EXPORT_SYMBOL_GPL(bcsr_mod); + +/* + * DB1200/PB1200 CPLD IRQ muxer + */ +static void bcsr_csc_handler(unsigned int irq, struct irq_desc *d) +{ + unsigned short bisr = __raw_readw(bcsr_virt + BCSR_REG_INTSTAT); + + for ( ; bisr; bisr &= bisr - 1) + generic_handle_irq(bcsr_csc_base + __ffs(bisr)); +} + +/* NOTE: both the enable and mask bits must be cleared, otherwise the + * CPLD generates tons of spurious interrupts (at least on my DB1200). + * -- mlau + */ +static void bcsr_irq_mask(unsigned int irq_nr) +{ + unsigned short v = 1 << (irq_nr - bcsr_csc_base); + __raw_writew(v, bcsr_virt + BCSR_REG_INTCLR); + __raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR); + wmb(); +} + +static void bcsr_irq_maskack(unsigned int irq_nr) +{ + unsigned short v = 1 << (irq_nr - bcsr_csc_base); + __raw_writew(v, bcsr_virt + BCSR_REG_INTCLR); + __raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR); + __raw_writew(v, bcsr_virt + BCSR_REG_INTSTAT); /* ack */ + wmb(); +} + +static void bcsr_irq_unmask(unsigned int irq_nr) +{ + unsigned short v = 1 << (irq_nr - bcsr_csc_base); + __raw_writew(v, bcsr_virt + BCSR_REG_INTSET); + __raw_writew(v, bcsr_virt + BCSR_REG_MASKSET); + wmb(); +} + +static struct irq_chip bcsr_irq_type = { + .name = "CPLD", + .mask = bcsr_irq_mask, + .mask_ack = bcsr_irq_maskack, + .unmask = bcsr_irq_unmask, +}; + +void __init bcsr_init_irq(int csc_start, int csc_end, int hook_irq) +{ + unsigned int irq; + + /* mask & disable & ack all */ + __raw_writew(0xffff, bcsr_virt + BCSR_REG_INTCLR); + __raw_writew(0xffff, bcsr_virt + BCSR_REG_MASKCLR); + __raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSTAT); + wmb(); + + bcsr_csc_base = csc_start; + + for (irq = csc_start; irq <= csc_end; irq++) + set_irq_chip_and_handler_name(irq, &bcsr_irq_type, + handle_level_irq, "level"); + + set_irq_chained_handler(hook_irq, bcsr_csc_handler); +} |