diff options
Diffstat (limited to 'arch/arm/mach-davinci/cp_intc.c')
| -rw-r--r-- | arch/arm/mach-davinci/cp_intc.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/cp_intc.c b/arch/arm/mach-davinci/cp_intc.c new file mode 100644 index 000000000000..96c8e97a7deb --- /dev/null +++ b/arch/arm/mach-davinci/cp_intc.c @@ -0,0 +1,161 @@ +/* + * TI Common Platform Interrupt Controller (cp_intc) driver + * + * Author: Steve Chen <schen@mvista.com> + * Copyright (C) 2008-2009, MontaVista Software, Inc. <source@mvista.com> + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ + +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/irq.h> +#include <linux/io.h> + +#include <mach/cp_intc.h> + +static void __iomem *cp_intc_base; + +static inline unsigned int cp_intc_read(unsigned offset) +{ + return __raw_readl(cp_intc_base + offset); +} + +static inline void cp_intc_write(unsigned long value, unsigned offset) +{ + __raw_writel(value, cp_intc_base + offset); +} + +static void cp_intc_ack_irq(unsigned int irq) +{ + cp_intc_write(irq, CP_INTC_SYS_STAT_IDX_CLR); +} + +/* Disable interrupt */ +static void cp_intc_mask_irq(unsigned int irq) +{ + /* XXX don't know why we need to disable nIRQ here... */ + cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_CLR); + cp_intc_write(irq, CP_INTC_SYS_ENABLE_IDX_CLR); + cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_SET); +} + +/* Enable interrupt */ +static void cp_intc_unmask_irq(unsigned int irq) +{ + cp_intc_write(irq, CP_INTC_SYS_ENABLE_IDX_SET); +} + +static int cp_intc_set_irq_type(unsigned int irq, unsigned int flow_type) +{ + unsigned reg = BIT_WORD(irq); + unsigned mask = BIT_MASK(irq); + unsigned polarity = cp_intc_read(CP_INTC_SYS_POLARITY(reg)); + unsigned type = cp_intc_read(CP_INTC_SYS_TYPE(reg)); + + switch (flow_type) { + case IRQ_TYPE_EDGE_RISING: + polarity |= mask; + type |= mask; + break; + case IRQ_TYPE_EDGE_FALLING: + polarity &= ~mask; + type |= mask; + break; + case IRQ_TYPE_LEVEL_HIGH: + polarity |= mask; + type &= ~mask; + break; + case IRQ_TYPE_LEVEL_LOW: + polarity &= ~mask; + type &= ~mask; + break; + default: + return -EINVAL; + } + + cp_intc_write(polarity, CP_INTC_SYS_POLARITY(reg)); + cp_intc_write(type, CP_INTC_SYS_TYPE(reg)); + + return 0; +} + +static struct irq_chip cp_intc_irq_chip = { + .name = "cp_intc", + .ack = cp_intc_ack_irq, + .mask = cp_intc_mask_irq, + .unmask = cp_intc_unmask_irq, + .set_type = cp_intc_set_irq_type, +}; + +void __init cp_intc_init(void __iomem *base, unsigned short num_irq, + u8 *irq_prio) +{ + unsigned num_reg = BITS_TO_LONGS(num_irq); + int i; + + cp_intc_base = base; + + cp_intc_write(0, CP_INTC_GLOBAL_ENABLE); + + /* Disable all host interrupts */ + cp_intc_write(0, CP_INTC_HOST_ENABLE(0)); + + /* Disable system interrupts */ + for (i = 0; i < num_reg; i++) + cp_intc_write(~0, CP_INTC_SYS_ENABLE_CLR(i)); + + /* Set to normal mode, no nesting, no priority hold */ + cp_intc_write(0, CP_INTC_CTRL); + cp_intc_write(0, CP_INTC_HOST_CTRL); + + /* Clear system interrupt status */ + for (i = 0; i < num_reg; i++) + cp_intc_write(~0, CP_INTC_SYS_STAT_CLR(i)); + + /* Enable nIRQ (what about nFIQ?) */ + cp_intc_write(1, CP_INTC_HOST_ENABLE_IDX_SET); + + /* + * Priority is determined by host channel: lower channel number has + * higher priority i.e. channel 0 has highest priority and channel 31 + * had the lowest priority. + */ + num_reg = (num_irq + 3) >> 2; /* 4 channels per register */ + if (irq_prio) { + unsigned j, k; + u32 val; + + for (k = i = 0; i < num_reg; i++) { + for (val = j = 0; j < 4; j++, k++) { + val >>= 8; + if (k < num_irq) + val |= irq_prio[k] << 24; + } + + cp_intc_write(val, CP_INTC_CHAN_MAP(i)); + } + } else { + /* + * Default everything to channel 15 if priority not specified. + * Note that channel 0-1 are mapped to nFIQ and channels 2-31 + * are mapped to nIRQ. + */ + for (i = 0; i < num_reg; i++) + cp_intc_write(0x0f0f0f0f, CP_INTC_CHAN_MAP(i)); + } + + /* Set up genirq dispatching for cp_intc */ + for (i = 0; i < num_irq; i++) { + set_irq_chip(i, &cp_intc_irq_chip); + set_irq_flags(i, IRQF_VALID | IRQF_PROBE); + set_irq_handler(i, handle_edge_irq); + } + + /* Enable global interrupt */ + cp_intc_write(1, CP_INTC_GLOBAL_ENABLE); +} |