Commit 3e694d4b authored by Ben Dooks's avatar Ben Dooks
Browse files

[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: default avatarBen Dooks <ben-linux@fluff.org>
parent b73c289c

arch/arm/mach-s3c6400/include/mach/map.h

+8 −0
Original line number Diff line number Diff line
@@ -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)

arch/arm/plat-s3c64xx/irq.c

+139 −1
Original line number Diff line number Diff line
@@ -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]);

}