diff options
Diffstat (limited to 'arch/arm/plat-samsung/irq-uart.c')
| -rw-r--r-- | arch/arm/plat-samsung/irq-uart.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/arm/plat-samsung/irq-uart.c b/arch/arm/plat-samsung/irq-uart.c new file mode 100644 index 000000000000..4f8c102674ae --- /dev/null +++ b/arch/arm/plat-samsung/irq-uart.c @@ -0,0 +1,143 @@ +/* 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(unsigned int irq) +{ + struct s3c_uart_irq *uirq = get_irq_chip_data(irq); + return uirq->regs; +} + +static inline unsigned int s3c_irq_uart_bit(unsigned int irq) +{ + return irq & 3; +} + +static void s3c_irq_uart_mask(unsigned int irq) +{ + void __iomem *regs = s3c_irq_uart_base(irq); + unsigned int bit = s3c_irq_uart_bit(irq); + u32 reg; + + reg = __raw_readl(regs + S3C64XX_UINTM); + reg |= (1 << bit); + __raw_writel(reg, regs + S3C64XX_UINTM); +} + +static void s3c_irq_uart_maskack(unsigned int irq) +{ + void __iomem *regs = s3c_irq_uart_base(irq); + unsigned int bit = s3c_irq_uart_bit(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(unsigned int irq) +{ + void __iomem *regs = s3c_irq_uart_base(irq); + unsigned int bit = s3c_irq_uart_bit(irq); + u32 reg; + + reg = __raw_readl(regs + S3C64XX_UINTM); + reg &= ~(1 << bit); + __raw_writel(reg, regs + S3C64XX_UINTM); +} + +static void s3c_irq_uart_ack(unsigned int irq) +{ + void __iomem *regs = s3c_irq_uart_base(irq); + unsigned int bit = s3c_irq_uart_bit(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->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", + .mask = s3c_irq_uart_mask, + .unmask = s3c_irq_uart_unmask, + .mask_ack = s3c_irq_uart_maskack, + .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->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); +} |