[linux-2.6-block.git] / arch / powerpc / sysdev / ge / ge_pic.c

/*
 * Interrupt handling for GE FPGA based PIC
 *
 * Author: Martyn Welch <martyn.welch@ge.com>
 *
 * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
 *
 * 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/stddef.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/spinlock.h>

#include <asm/byteorder.h>
#include <asm/io.h>
#include <asm/irq.h>

#include "ge_pic.h"

#define DEBUG
#undef DEBUG

#ifdef DEBUG
#define DBG(fmt...) do { printk(KERN_DEBUG "gef_pic: " fmt); } while (0)
#else
#define DBG(fmt...) do { } while (0)
#endif

#define GEF_PIC_NUM_IRQS	32

/* Interrupt Controller Interface Registers */
#define GEF_PIC_INTR_STATUS	0x0000

#define GEF_PIC_INTR_MASK(cpu)	(0x0010 + (0x4 * cpu))
#define GEF_PIC_CPU0_INTR_MASK	GEF_PIC_INTR_MASK(0)
#define GEF_PIC_CPU1_INTR_MASK	GEF_PIC_INTR_MASK(1)

#define GEF_PIC_MCP_MASK(cpu)	(0x0018 + (0x4 * cpu))
#define GEF_PIC_CPU0_MCP_MASK	GEF_PIC_MCP_MASK(0)
#define GEF_PIC_CPU1_MCP_MASK	GEF_PIC_MCP_MASK(1)


static DEFINE_RAW_SPINLOCK(gef_pic_lock);

static void __iomem *gef_pic_irq_reg_base;
static struct irq_domain *gef_pic_irq_host;
static int gef_pic_cascade_irq;

/*
 * Interrupt Controller Handling
 *
 * The interrupt controller handles interrupts for most on board interrupts,
 * apart from PCI interrupts. For example on SBC610:
 *
 * 17:31 RO Reserved
 * 16    RO PCI Express Doorbell 3 Status
 * 15    RO PCI Express Doorbell 2 Status
 * 14    RO PCI Express Doorbell 1 Status
 * 13    RO PCI Express Doorbell 0 Status
 * 12    RO Real Time Clock Interrupt Status
 * 11    RO Temperature Interrupt Status
 * 10    RO Temperature Critical Interrupt Status
 * 9     RO Ethernet PHY1 Interrupt Status
 * 8     RO Ethernet PHY3 Interrupt Status
 * 7     RO PEX8548 Interrupt Status
 * 6     RO Reserved
 * 5     RO Watchdog 0 Interrupt Status
 * 4     RO Watchdog 1 Interrupt Status
 * 3     RO AXIS Message FIFO A Interrupt Status
 * 2     RO AXIS Message FIFO B Interrupt Status
 * 1     RO AXIS Message FIFO C Interrupt Status
 * 0     RO AXIS Message FIFO D Interrupt Status
 *
 * Interrupts can be forwarded to one of two output lines. Nothing
 * clever is done, so if the masks are incorrectly set, a single input
 * interrupt could generate interrupts on both output lines!
 *
 * The dual lines are there to allow the chained interrupts to be easily
 * passed into two different cores. We currently do not use this functionality
 * in this driver.
 *
 * Controller can also be configured to generate Machine checks (MCP), again on
 * two lines, to be attached to two different cores. It is suggested that these
 * should be masked out.
 */

static void gef_pic_cascade(struct irq_desc *desc)
{
	struct irq_chip *chip = irq_desc_get_chip(desc);
	unsigned int cascade_irq;

	/*
	 * See if we actually have an interrupt, call generic handling code if
	 * we do.
	 */
	cascade_irq = gef_pic_get_irq();

	if (cascade_irq)
		generic_handle_irq(cascade_irq);

	chip->irq_eoi(&desc->irq_data);
}

static void gef_pic_mask(struct irq_data *d)
{
	unsigned long flags;
	unsigned int hwirq = irqd_to_hwirq(d);
	u32 mask;

	raw_spin_lock_irqsave(&gef_pic_lock, flags);
	mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
	mask &= ~(1 << hwirq);
	out_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0), mask);
	raw_spin_unlock_irqrestore(&gef_pic_lock, flags);
}

static void gef_pic_mask_ack(struct irq_data *d)
{
	/* Don't think we actually have to do anything to ack an interrupt,
	 * we just need to clear down the devices interrupt and it will go away
	 */
	gef_pic_mask(d);
}

static void gef_pic_unmask(struct irq_data *d)
{
	unsigned long flags;
	unsigned int hwirq = irqd_to_hwirq(d);
	u32 mask;

	raw_spin_lock_irqsave(&gef_pic_lock, flags);
	mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
	mask |= (1 << hwirq);
	out_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0), mask);
	raw_spin_unlock_irqrestore(&gef_pic_lock, flags);
}

static struct irq_chip gef_pic_chip = {
	.name		= "gefp",
	.irq_mask	= gef_pic_mask,
	.irq_mask_ack	= gef_pic_mask_ack,
	.irq_unmask	= gef_pic_unmask,
};


/* When an interrupt is being configured, this call allows some flexibility
 * in deciding which irq_chip structure is used
 */
static int gef_pic_host_map(struct irq_domain *h, unsigned int virq,
			  irq_hw_number_t hwirq)
{
	/* All interrupts are LEVEL sensitive */
	irq_set_status_flags(virq, IRQ_LEVEL);
	irq_set_chip_and_handler(virq, &gef_pic_chip, handle_level_irq);

	return 0;
}

static int gef_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
			    const u32 *intspec, unsigned int intsize,
			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
{

	*out_hwirq = intspec[0];
	if (intsize > 1)
		*out_flags = intspec[1];
	else
		*out_flags = IRQ_TYPE_LEVEL_HIGH;

	return 0;
}

static const struct irq_domain_ops gef_pic_host_ops = {
	.map	= gef_pic_host_map,
	.xlate	= gef_pic_host_xlate,
};


/*
 * Initialisation of PIC, this should be called in BSP
 */
void __init gef_pic_init(struct device_node *np)
{
	unsigned long flags;

	/* Map the devices registers into memory */
	gef_pic_irq_reg_base = of_iomap(np, 0);

	raw_spin_lock_irqsave(&gef_pic_lock, flags);

	/* Initialise everything as masked. */
	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU0_INTR_MASK, 0);
	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU1_INTR_MASK, 0);

	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU0_MCP_MASK, 0);
	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU1_MCP_MASK, 0);

	raw_spin_unlock_irqrestore(&gef_pic_lock, flags);

	/* Map controller */
	gef_pic_cascade_irq = irq_of_parse_and_map(np, 0);
	if (!gef_pic_cascade_irq) {
		printk(KERN_ERR "SBC610: failed to map cascade interrupt");
		return;
	}

	/* Setup an irq_domain structure */
	gef_pic_irq_host = irq_domain_add_linear(np, GEF_PIC_NUM_IRQS,
					  &gef_pic_host_ops, NULL);
	if (gef_pic_irq_host == NULL)
		return;

	/* Chain with parent controller */
	irq_set_chained_handler(gef_pic_cascade_irq, gef_pic_cascade);
}

/*
 * This is called when we receive an interrupt with apparently comes from this
 * chip - check, returning the highest interrupt generated or return 0.
 */
unsigned int gef_pic_get_irq(void)
{
	u32 cause, mask, active;
	unsigned int virq = 0;
	int hwirq;

	cause = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_STATUS);

	mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));

	active = cause & mask;

	if (active) {
		for (hwirq = GEF_PIC_NUM_IRQS - 1; hwirq > -1; hwirq--) {
			if (active & (0x1 << hwirq))
				break;
		}
		virq = irq_linear_revmap(gef_pic_irq_host,
			(irq_hw_number_t)hwirq);
	}

	return virq;
}
Commit	Line	Data
3a470247	1	/*
948e78c3	2	* Interrupt handling for GE FPGA based PIC
3a470247	3	*
948e78c3	4	* Author: Martyn Welch <martyn.welch@ge.com>
3a470247	5	*
948e78c3	6	* 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
3a470247 MW	7	*
	8	* This file is licensed under the terms of the GNU General Public License
	9	* version 2. This program is licensed "as is" without any warranty of any
	10	* kind, whether express or implied.
	11	*/
	12
	13	#include <linux/stddef.h>
	14	#include <linux/kernel.h>
	15	#include <linux/init.h>
	16	#include <linux/irq.h>
e6f6390a	17	#include <linux/irqdomain.h>
3a470247	18	#include <linux/interrupt.h>
e6f6390a CL	19	#include <linux/of_address.h>
e6f6390a CL	20	#include <linux/of_irq.h>
3a470247 MW	21	#include <linux/spinlock.h>
	22
	23	#include <asm/byteorder.h>
	24	#include <asm/io.h>
3a470247 MW	25	#include <asm/irq.h>
3a470247 MW	26
44b24b74	27	#include "ge_pic.h"
3a470247 MW	28
	29	#define DEBUG
	30	#undef DEBUG
	31
	32	#ifdef DEBUG
	33	#define DBG(fmt...) do { printk(KERN_DEBUG "gef_pic: " fmt); } while (0)
	34	#else
	35	#define DBG(fmt...) do { } while (0)
	36	#endif
	37
	38	#define GEF_PIC_NUM_IRQS 32
	39
	40	/* Interrupt Controller Interface Registers */
	41	#define GEF_PIC_INTR_STATUS 0x0000
	42
	43	#define GEF_PIC_INTR_MASK(cpu) (0x0010 + (0x4 * cpu))
	44	#define GEF_PIC_CPU0_INTR_MASK GEF_PIC_INTR_MASK(0)
	45	#define GEF_PIC_CPU1_INTR_MASK GEF_PIC_INTR_MASK(1)
	46
	47	#define GEF_PIC_MCP_MASK(cpu) (0x0018 + (0x4 * cpu))
	48	#define GEF_PIC_CPU0_MCP_MASK GEF_PIC_MCP_MASK(0)
	49	#define GEF_PIC_CPU1_MCP_MASK GEF_PIC_MCP_MASK(1)
	50
3a470247	51
6f3d395a	52	static DEFINE_RAW_SPINLOCK(gef_pic_lock);
3a470247 MW	53
3a470247 MW	54	static void __iomem *gef_pic_irq_reg_base;
bae1d8f1	55	static struct irq_domain *gef_pic_irq_host;
3a470247 MW	56	static int gef_pic_cascade_irq;
	57
	58	/*
	59	* Interrupt Controller Handling
	60	*
	61	* The interrupt controller handles interrupts for most on board interrupts,
	62	* apart from PCI interrupts. For example on SBC610:
	63	*
	64	* 17:31 RO Reserved
	65	* 16 RO PCI Express Doorbell 3 Status
	66	* 15 RO PCI Express Doorbell 2 Status
	67	* 14 RO PCI Express Doorbell 1 Status
	68	* 13 RO PCI Express Doorbell 0 Status
	69	* 12 RO Real Time Clock Interrupt Status
	70	* 11 RO Temperature Interrupt Status
	71	* 10 RO Temperature Critical Interrupt Status
	72	* 9 RO Ethernet PHY1 Interrupt Status
	73	* 8 RO Ethernet PHY3 Interrupt Status
	74	* 7 RO PEX8548 Interrupt Status
	75	* 6 RO Reserved
	76	* 5 RO Watchdog 0 Interrupt Status
	77	* 4 RO Watchdog 1 Interrupt Status
	78	* 3 RO AXIS Message FIFO A Interrupt Status
	79	* 2 RO AXIS Message FIFO B Interrupt Status
	80	* 1 RO AXIS Message FIFO C Interrupt Status
	81	* 0 RO AXIS Message FIFO D Interrupt Status
	82	*
	83	* Interrupts can be forwarded to one of two output lines. Nothing
	84	* clever is done, so if the masks are incorrectly set, a single input
	85	* interrupt could generate interrupts on both output lines!
	86	*
	87	* The dual lines are there to allow the chained interrupts to be easily
	88	* passed into two different cores. We currently do not use this functionality
	89	* in this driver.
	90	*
	91	* Controller can also be configured to generate Machine checks (MCP), again on
	92	* two lines, to be attached to two different cores. It is suggested that these
	93	* should be masked out.
	94	*/
	95
bd0b9ac4	96	static void gef_pic_cascade(struct irq_desc *desc)
3a470247	97	{
ec775d0e	98	struct irq_chip *chip = irq_desc_get_chip(desc);
3a470247 MW	99	unsigned int cascade_irq;
	100
	101	/*
	102	* See if we actually have an interrupt, call generic handling code if
	103	* we do.
	104	*/
	105	cascade_irq = gef_pic_get_irq();
	106
ef24ba70	107	if (cascade_irq)
3a470247 MW	108	generic_handle_irq(cascade_irq);
3a470247 MW	109
5b250889	110	chip->irq_eoi(&desc->irq_data);
3a470247 MW	111	}
3a470247 MW	112
5b250889	113	static void gef_pic_mask(struct irq_data *d)
3a470247 MW	114	{
3a470247 MW	115	unsigned long flags;
476eb491	116	unsigned int hwirq = irqd_to_hwirq(d);
3a470247 MW	117	u32 mask;
3a470247 MW	118
6f3d395a	119	raw_spin_lock_irqsave(&gef_pic_lock, flags);
3a470247 MW	120	mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
	121	mask &= ~(1 << hwirq);
	122	out_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0), mask);
6f3d395a	123	raw_spin_unlock_irqrestore(&gef_pic_lock, flags);
3a470247 MW	124	}
3a470247 MW	125
5b250889	126	static void gef_pic_mask_ack(struct irq_data *d)
3a470247 MW	127	{
	128	/* Don't think we actually have to do anything to ack an interrupt,
	129	* we just need to clear down the devices interrupt and it will go away
	130	*/
5b250889	131	gef_pic_mask(d);
3a470247 MW	132	}
3a470247 MW	133
5b250889	134	static void gef_pic_unmask(struct irq_data *d)
3a470247 MW	135	{
3a470247 MW	136	unsigned long flags;
476eb491	137	unsigned int hwirq = irqd_to_hwirq(d);
3a470247 MW	138	u32 mask;
3a470247 MW	139
6f3d395a	140	raw_spin_lock_irqsave(&gef_pic_lock, flags);
3a470247 MW	141	mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
	142	mask \|= (1 << hwirq);
	143	out_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0), mask);
6f3d395a	144	raw_spin_unlock_irqrestore(&gef_pic_lock, flags);
3a470247 MW	145	}
	146
	147	static struct irq_chip gef_pic_chip = {
b27df672	148	.name = "gefp",
5b250889 LB	149	.irq_mask = gef_pic_mask,
	150	.irq_mask_ack = gef_pic_mask_ack,
	151	.irq_unmask = gef_pic_unmask,
3a470247 MW	152	};
	153
	154
1fd02f66	155	/* When an interrupt is being configured, this call allows some flexibility
3a470247 MW	156	* in deciding which irq_chip structure is used
3a470247 MW	157	*/
bae1d8f1	158	static int gef_pic_host_map(struct irq_domain *h, unsigned int virq,
3a470247 MW	159	irq_hw_number_t hwirq)
	160	{
	161	/* All interrupts are LEVEL sensitive */
98488db9	162	irq_set_status_flags(virq, IRQ_LEVEL);
ec775d0e	163	irq_set_chip_and_handler(virq, &gef_pic_chip, handle_level_irq);
3a470247 MW	164
	165	return 0;
	166	}
	167
bae1d8f1	168	static int gef_pic_host_xlate(struct irq_domain h, struct device_node ct,
40d50cf7	169	const u32 *intspec, unsigned int intsize,
3a470247 MW	170	irq_hw_number_t out_hwirq, unsigned int out_flags)
	171	{
	172
	173	*out_hwirq = intspec[0];
	174	if (intsize > 1)
	175	*out_flags = intspec[1];
	176	else
	177	*out_flags = IRQ_TYPE_LEVEL_HIGH;
	178
	179	return 0;
	180	}
	181
9f70b8eb	182	static const struct irq_domain_ops gef_pic_host_ops = {
3a470247 MW	183	.map = gef_pic_host_map,
	184	.xlate = gef_pic_host_xlate,
	185	};
	186
	187
	188	/*
	189	* Initialisation of PIC, this should be called in BSP
	190	*/
	191	void __init gef_pic_init(struct device_node *np)
	192	{
	193	unsigned long flags;
	194
	195	/* Map the devices registers into memory */
	196	gef_pic_irq_reg_base = of_iomap(np, 0);
	197
6f3d395a	198	raw_spin_lock_irqsave(&gef_pic_lock, flags);
3a470247 MW	199
	200	/* Initialise everything as masked. */
	201	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU0_INTR_MASK, 0);
	202	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU1_INTR_MASK, 0);
	203
	204	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU0_MCP_MASK, 0);
	205	out_be32(gef_pic_irq_reg_base + GEF_PIC_CPU1_MCP_MASK, 0);
	206
6f3d395a	207	raw_spin_unlock_irqrestore(&gef_pic_lock, flags);
3a470247 MW	208
	209	/* Map controller */
	210	gef_pic_cascade_irq = irq_of_parse_and_map(np, 0);
ef24ba70	211	if (!gef_pic_cascade_irq) {
3a470247 MW	212	printk(KERN_ERR "SBC610: failed to map cascade interrupt");
	213	return;
	214	}
	215
bae1d8f1	216	/* Setup an irq_domain structure */
a8db8cf0 GL	217	gef_pic_irq_host = irq_domain_add_linear(np, GEF_PIC_NUM_IRQS,
a8db8cf0 GL	218	&gef_pic_host_ops, NULL);
3a470247 MW	219	if (gef_pic_irq_host == NULL)
	220	return;
	221
	222	/* Chain with parent controller */
ec775d0e	223	irq_set_chained_handler(gef_pic_cascade_irq, gef_pic_cascade);
3a470247 MW	224	}
	225
	226	/*
	227	* This is called when we receive an interrupt with apparently comes from this
ef24ba70	228	* chip - check, returning the highest interrupt generated or return 0.
3a470247 MW	229	*/
	230	unsigned int gef_pic_get_irq(void)
	231	{
	232	u32 cause, mask, active;
ef24ba70	233	unsigned int virq = 0;
3a470247 MW	234	int hwirq;
	235
	236	cause = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_STATUS);
	237
	238	mask = in_be32(gef_pic_irq_reg_base + GEF_PIC_INTR_MASK(0));
	239
	240	active = cause & mask;
	241
	242	if (active) {
	243	for (hwirq = GEF_PIC_NUM_IRQS - 1; hwirq > -1; hwirq--) {
	244	if (active & (0x1 << hwirq))
	245	break;
	246	}
	247	virq = irq_linear_revmap(gef_pic_irq_host,
	248	(irq_hw_number_t)hwirq);
	249	}
	250
	251	return virq;
	252	}
	253