[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/plat-s3c64xx/irq.c b/arch/arm/plat-s3c64xx/irq.c
index 1e6fa5c..99df9db 100644
--- a/arch/arm/plat-s3c64xx/irq.c
+++ b/arch/arm/plat-s3c64xx/irq.c
@@ -91,9 +91,144 @@
.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 @@
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]);
}