pic.c

  1#include <linux/kernel.h>
  2#include <linux/stddef.h>
  3#include <linux/sched.h>
  4#include <linux/signal.h>
  5#include <linux/irq.h>
  6#include <linux/dma-mapping.h>
  7#include <linux/of_address.h>
  8#include <linux/of_irq.h>
  9#include <asm/irq.h>
 10#include <asm/io.h>
 11#include <asm/8xx_immap.h>
 12
 13#include "pic.h"
 14
 15
 16#define PIC_VEC_SPURRIOUS      15
 17
 18static struct irq_domain *mpc8xx_pic_host;
 19static unsigned long mpc8xx_cached_irq_mask;
 20static sysconf8xx_t __iomem *siu_reg;
 21
 22static inline unsigned long mpc8xx_irqd_to_bit(struct irq_data *d)
 23{
 24	return 0x80000000 >> irqd_to_hwirq(d);
 25}
 26
 27static void mpc8xx_unmask_irq(struct irq_data *d)
 28{
 29	mpc8xx_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
 30	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
 31}
 32
 33static void mpc8xx_mask_irq(struct irq_data *d)
 34{
 35	mpc8xx_cached_irq_mask &= ~mpc8xx_irqd_to_bit(d);
 36	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
 37}
 38
 39static void mpc8xx_ack(struct irq_data *d)
 40{
 41	out_be32(&siu_reg->sc_sipend, mpc8xx_irqd_to_bit(d));
 42}
 43
 44static void mpc8xx_end_irq(struct irq_data *d)
 45{
 46	mpc8xx_cached_irq_mask |= mpc8xx_irqd_to_bit(d);
 47	out_be32(&siu_reg->sc_simask, mpc8xx_cached_irq_mask);
 48}
 49
 50static int mpc8xx_set_irq_type(struct irq_data *d, unsigned int flow_type)
 51{
 52	/* only external IRQ senses are programmable */
 53	if ((flow_type & IRQ_TYPE_EDGE_FALLING) && !(irqd_to_hwirq(d) & 1)) {
 54		unsigned int siel = in_be32(&siu_reg->sc_siel);
 55		siel |= mpc8xx_irqd_to_bit(d);
 56		out_be32(&siu_reg->sc_siel, siel);
 57		irq_set_handler_locked(d, handle_edge_irq);
 58	}
 59	return 0;
 60}
 61
 62static struct irq_chip mpc8xx_pic = {
 63	.name = "8XX SIU",
 64	.irq_unmask = mpc8xx_unmask_irq,
 65	.irq_mask = mpc8xx_mask_irq,
 66	.irq_ack = mpc8xx_ack,
 67	.irq_eoi = mpc8xx_end_irq,
 68	.irq_set_type = mpc8xx_set_irq_type,
 69};
 70
 71unsigned int mpc8xx_get_irq(void)
 72{
 73	int irq;
 74
 75	/* For MPC8xx, read the SIVEC register and shift the bits down
 76	 * to get the irq number.
 77	 */
 78	irq = in_be32(&siu_reg->sc_sivec) >> 26;
 79
 80	if (irq == PIC_VEC_SPURRIOUS)
 81		return 0;
 82
 83        return irq_find_mapping(mpc8xx_pic_host, irq);
 84
 85}
 86
 87static int mpc8xx_pic_host_map(struct irq_domain *h, unsigned int virq,
 88			  irq_hw_number_t hw)
 89{
 90	pr_debug("mpc8xx_pic_host_map(%d, 0x%lx)\n", virq, hw);
 91
 92	/* Set default irq handle */
 93	irq_set_chip_and_handler(virq, &mpc8xx_pic, handle_level_irq);
 94	return 0;
 95}
 96
 97
 98static int mpc8xx_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 99			    const u32 *intspec, unsigned int intsize,
100			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
101{
102	static unsigned char map_pic_senses[4] = {
103		IRQ_TYPE_EDGE_RISING,
104		IRQ_TYPE_LEVEL_LOW,
105		IRQ_TYPE_LEVEL_HIGH,
106		IRQ_TYPE_EDGE_FALLING,
107	};
108
109	if (intspec[0] > 0x1f)
110		return 0;
111
112	*out_hwirq = intspec[0];
113	if (intsize > 1 && intspec[1] < 4)
114		*out_flags = map_pic_senses[intspec[1]];
115	else
116		*out_flags = IRQ_TYPE_NONE;
117
118	return 0;
119}
120
121
122static const struct irq_domain_ops mpc8xx_pic_host_ops = {
123	.map = mpc8xx_pic_host_map,
124	.xlate = mpc8xx_pic_host_xlate,
125};
126
127void __init mpc8xx_pic_init(void)
128{
129	struct resource res;
130	struct device_node *np;
131	int ret;
132
133	np = of_find_compatible_node(NULL, NULL, "fsl,pq1-pic");
134	if (np == NULL)
135		np = of_find_node_by_type(NULL, "mpc8xx-pic");
136	if (np == NULL) {
137		printk(KERN_ERR "Could not find fsl,pq1-pic node\n");
138		return;
139	}
140
141	ret = of_address_to_resource(np, 0, &res);
142	if (ret)
143		goto out;
144
145	siu_reg = ioremap(res.start, resource_size(&res));
146	if (!siu_reg)
147		goto out;
148
149	mpc8xx_pic_host = irq_domain_create_linear(of_fwnode_handle(np), 64,
150						   &mpc8xx_pic_host_ops, NULL);
151	if (!mpc8xx_pic_host)
152		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
153
154out:
155	of_node_put(np);
156}