[ARM] S3C64XX: Demux UART interrupts

Add demux handling for the UART interrupts
generated by the VIC into their seperate IRQs
that the serial driver can register.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

diff --git a/arch/arm/mach-s3c6400/include/mach/map.h b/arch/arm/mach-s3c6400/include/mach/map.h
index de6cdd5..83ed3c1 100644 (file)
--- a/arch/arm/mach-s3c6400/include/mach/map.h
+++ b/arch/arm/mach-s3c6400/include/mach/map.h
@@ -24,6 +24,14 @@
 #define S3C_PA_UART3           (S3C_PA_UART + 0xC00)
 #define S3C_UART_OFFSET                (0x400)
 
+/* See notes on UART VA mapping in debug-macro.S */
+#define S3C_VA_UARTx(x)        (S3C_VA_UART + (S3C_PA_UART & 0xfffff) + ((x) * S3C_UART_OFFSET))
+
+#define S3C_VA_UART0           S3C_VA_UARTx(0)
+#define S3C_VA_UART1           S3C_VA_UARTx(1)
+#define S3C_VA_UART2           S3C_VA_UARTx(2)
+#define S3C_VA_UART3           S3C_VA_UARTx(3)
+
 #define S3C64XX_PA_SYSCON      (0x7E00F000)
 #define S3C64XX_PA_TIMER       (0x7F006000)
 

diff --git a/arch/arm/plat-s3c64xx/irq.c b/arch/arm/plat-s3c64xx/irq.c
index 1e6fa5c..99df9db 100644 (file)
--- a/arch/arm/plat-s3c64xx/irq.c
+++ b/arch/arm/plat-s3c64xx/irq.c
@@ -91,9 +91,144 @@ static struct irq_chip s3c_irq_timer = {
        .ack            = s3c_irq_timer_ack,
 };
 
+struct uart_irq {
+       void __iomem    *regs;
+       unsigned int     base_irq;
+       unsigned int     parent_irq;
+};
+
+/* 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 struct uart_irq uart_irqs[] = {
+       [0] = {
+               .regs           = S3C_VA_UART0,
+               .base_irq       = IRQ_S3CUART_BASE0,
+               .parent_irq     = IRQ_UART0,
+       },
+       [1] = {
+               .regs           = S3C_VA_UART1,
+               .base_irq       = IRQ_S3CUART_BASE1,
+               .parent_irq     = IRQ_UART1,
+       },
+       [2] = {
+               .regs           = S3C_VA_UART2,
+               .base_irq       = IRQ_S3CUART_BASE2,
+               .parent_irq     = IRQ_UART2,
+       },
+       [3] = {
+               .regs           = S3C_VA_UART3,
+               .base_irq       = IRQ_S3CUART_BASE3,
+               .parent_irq     = IRQ_UART3,
+       },
+};
+
+static inline void __iomem *s3c_irq_uart_base(unsigned int irq)
+{
+       struct 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;
+}
+
+/* UART interrupt registers, not worth adding to seperate include header */
+#define S3C64XX_UINTP  0x30
+#define S3C64XX_UINTSP 0x34
+#define S3C64XX_UINTM  0x38
+
+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 uart_irq *uirq = &uart_irqs[irq - IRQ_UART0];
+       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 s3c64xx_uart_irq(struct uart_irq *uirq)
+{
+       void *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);
+       }
+
+       set_irq_chained_handler(uirq->parent_irq, s3c_irq_demux_uart);
+}
+
 void __init s3c64xx_init_irq(u32 vic0_valid, u32 vic1_valid)
 {
-       int irq;
+       int uart, irq;
 
        printk(KERN_INFO "%s: initialising interrupts\n", __func__);
 
@@ -114,6 +249,9 @@ void __init s3c64xx_init_irq(u32 vic0_valid, u32 vic1_valid)
                set_irq_handler(irq, handle_level_irq);
                set_irq_flags(irq, IRQF_VALID);
        }
+
+       for (uart = 0; uart < ARRAY_SIZE(uart_irqs); uart++)
+               s3c64xx_uart_irq(&uart_irqs[uart]);
 }