1 /*
2  * Support for 'media5200-platform' compatible boards.
3  *
4  * Copyright (C) 2008 Secret Lab Technologies Ltd.
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  *
11  * Description:
12  * This code implements support for the Freescape Media5200 platform
13  * (built around the MPC5200 SoC).
14  *
15  * Notable characteristic of the Media5200 is the presence of an FPGA
16  * that has all external IRQ lines routed through it.  This file implements
17  * a cascaded interrupt controller driver which attaches itself to the
18  * Virtual IRQ subsystem after the primary mpc5200 interrupt controller
19  * is initialized.
20  *
21  */
22 
23 #undef DEBUG
24 
25 #include <linux/irq.h>
26 #include <linux/interrupt.h>
27 #include <linux/io.h>
28 #include <asm/time.h>
29 #include <asm/prom.h>
30 #include <asm/machdep.h>
31 #include <asm/mpc52xx.h>
32 
33 static struct of_device_id mpc5200_gpio_ids[] __initdata = {
34 	{ .compatible = "fsl,mpc5200-gpio", },
35 	{ .compatible = "mpc5200-gpio", },
36 	{}
37 };
38 
39 /* FPGA register set */
40 #define MEDIA5200_IRQ_ENABLE (0x40c)
41 #define MEDIA5200_IRQ_STATUS (0x410)
42 #define MEDIA5200_NUM_IRQS   (6)
43 #define MEDIA5200_IRQ_SHIFT  (32 - MEDIA5200_NUM_IRQS)
44 
45 struct media5200_irq {
46 	void __iomem *regs;
47 	spinlock_t lock;
48 	struct irq_host *irqhost;
49 };
50 struct media5200_irq media5200_irq;
51 
52 static void media5200_irq_unmask(unsigned int virq)
53 {
54 	unsigned long flags;
55 	u32 val;
56 
57 	spin_lock_irqsave(&media5200_irq.lock, flags);
58 	val = in_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE);
59 	val |= 1 << (MEDIA5200_IRQ_SHIFT + irq_map[virq].hwirq);
60 	out_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE, val);
61 	spin_unlock_irqrestore(&media5200_irq.lock, flags);
62 }
63 
64 static void media5200_irq_mask(unsigned int virq)
65 {
66 	unsigned long flags;
67 	u32 val;
68 
69 	spin_lock_irqsave(&media5200_irq.lock, flags);
70 	val = in_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE);
71 	val &= ~(1 << (MEDIA5200_IRQ_SHIFT + irq_map[virq].hwirq));
72 	out_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE, val);
73 	spin_unlock_irqrestore(&media5200_irq.lock, flags);
74 }
75 
76 static struct irq_chip media5200_irq_chip = {
77 	.typename = "Media5200 FPGA",
78 	.unmask = media5200_irq_unmask,
79 	.mask = media5200_irq_mask,
80 	.mask_ack = media5200_irq_mask,
81 };
82 
83 void media5200_irq_cascade(unsigned int virq, struct irq_desc *desc)
84 {
85 	int sub_virq, val;
86 	u32 status, enable;
87 
88 	/* Mask off the cascaded IRQ */
89 	spin_lock(&desc->lock);
90 	desc->chip->mask(virq);
91 	spin_unlock(&desc->lock);
92 
93 	/* Ask the FPGA for IRQ status.  If 'val' is 0, then no irqs
94 	 * are pending.  'ffs()' is 1 based */
95 	status = in_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE);
96 	enable = in_be32(media5200_irq.regs + MEDIA5200_IRQ_STATUS);
97 	val = ffs((status & enable) >> MEDIA5200_IRQ_SHIFT);
98 	if (val) {
99 		sub_virq = irq_linear_revmap(media5200_irq.irqhost, val - 1);
100 		/* pr_debug("%s: virq=%i s=%.8x e=%.8x hwirq=%i subvirq=%i\n",
101 		 *          __func__, virq, status, enable, val - 1, sub_virq);
102 		 */
103 		generic_handle_irq(sub_virq);
104 	}
105 
106 	/* Processing done; can reenable the cascade now */
107 	spin_lock(&desc->lock);
108 	desc->chip->ack(virq);
109 	if (!(desc->status & IRQ_DISABLED))
110 		desc->chip->unmask(virq);
111 	spin_unlock(&desc->lock);
112 }
113 
114 static int media5200_irq_map(struct irq_host *h, unsigned int virq,
115 			     irq_hw_number_t hw)
116 {
117 	struct irq_desc *desc = get_irq_desc(virq);
118 
119 	pr_debug("%s: h=%p, virq=%i, hwirq=%i\n", __func__, h, virq, (int)hw);
120 	set_irq_chip_data(virq, &media5200_irq);
121 	set_irq_chip_and_handler(virq, &media5200_irq_chip, handle_level_irq);
122 	set_irq_type(virq, IRQ_TYPE_LEVEL_LOW);
123 	desc->status &= ~(IRQ_TYPE_SENSE_MASK | IRQ_LEVEL);
124 	desc->status |= IRQ_TYPE_LEVEL_LOW | IRQ_LEVEL;
125 
126 	return 0;
127 }
128 
129 static int media5200_irq_xlate(struct irq_host *h, struct device_node *ct,
130 				 u32 *intspec, unsigned int intsize,
131 				 irq_hw_number_t *out_hwirq,
132 				 unsigned int *out_flags)
133 {
134 	if (intsize != 2)
135 		return -1;
136 
137 	pr_debug("%s: bank=%i, number=%i\n", __func__, intspec[0], intspec[1]);
138 	*out_hwirq = intspec[1];
139 	*out_flags = IRQ_TYPE_NONE;
140 	return 0;
141 }
142 
143 static struct irq_host_ops media5200_irq_ops = {
144 	.map = media5200_irq_map,
145 	.xlate = media5200_irq_xlate,
146 };
147 
148 /*
149  * Setup Media5200 IRQ mapping
150  */
151 static void __init media5200_init_irq(void)
152 {
153 	struct device_node *fpga_np;
154 	int cascade_virq;
155 
156 	/* First setup the regular MPC5200 interrupt controller */
157 	mpc52xx_init_irq();
158 
159 	/* Now find the FPGA IRQ */
160 	fpga_np = of_find_compatible_node(NULL, NULL, "fsl,media5200-fpga");
161 	if (!fpga_np)
162 		goto out;
163 	pr_debug("%s: found fpga node: %s\n", __func__, fpga_np->full_name);
164 
165 	media5200_irq.regs = of_iomap(fpga_np, 0);
166 	if (!media5200_irq.regs)
167 		goto out;
168 	pr_debug("%s: mapped to %p\n", __func__, media5200_irq.regs);
169 
170 	cascade_virq = irq_of_parse_and_map(fpga_np, 0);
171 	if (!cascade_virq)
172 		goto out;
173 	pr_debug("%s: cascaded on virq=%i\n", __func__, cascade_virq);
174 
175 	/* Disable all FPGA IRQs */
176 	out_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE, 0);
177 
178 	spin_lock_init(&media5200_irq.lock);
179 
180 	media5200_irq.irqhost = irq_alloc_host(fpga_np, IRQ_HOST_MAP_LINEAR,
181 					       MEDIA5200_NUM_IRQS,
182 					       &media5200_irq_ops, -1);
183 	if (!media5200_irq.irqhost)
184 		goto out;
185 	pr_debug("%s: allocated irqhost\n", __func__);
186 
187 	media5200_irq.irqhost->host_data = &media5200_irq;
188 
189 	set_irq_data(cascade_virq, &media5200_irq);
190 	set_irq_chained_handler(cascade_virq, media5200_irq_cascade);
191 
192 	return;
193 
194  out:
195 	pr_err("Could not find Media5200 FPGA; PCI interrupts will not work\n");
196 }
197 
198 /*
199  * Setup the architecture
200  */
201 static void __init media5200_setup_arch(void)
202 {
203 
204 	struct device_node *np;
205 	struct mpc52xx_gpio __iomem *gpio;
206 	u32 port_config;
207 
208 	if (ppc_md.progress)
209 		ppc_md.progress("media5200_setup_arch()", 0);
210 
211 	/* Map important registers from the internal memory map */
212 	mpc52xx_map_common_devices();
213 
214 	/* Some mpc5200 & mpc5200b related configuration */
215 	mpc5200_setup_xlb_arbiter();
216 
217 	mpc52xx_setup_pci();
218 
219 	np = of_find_matching_node(NULL, mpc5200_gpio_ids);
220 	gpio = of_iomap(np, 0);
221 	of_node_put(np);
222 	if (!gpio) {
223 		printk(KERN_ERR "%s() failed. expect abnormal behavior\n",
224 		       __func__);
225 		return;
226 	}
227 
228 	/* Set port config */
229 	port_config = in_be32(&gpio->port_config);
230 
231 	port_config &= ~0x03000000;	/* ATA CS is on csb_4/5		*/
232 	port_config |=  0x01000000;
233 
234 	out_be32(&gpio->port_config, port_config);
235 
236 	/* Unmap zone */
237 	iounmap(gpio);
238 
239 }
240 
241 /* list of the supported boards */
242 static char *board[] __initdata = {
243 	"fsl,media5200",
244 	NULL
245 };
246 
247 /*
248  * Called very early, MMU is off, device-tree isn't unflattened
249  */
250 static int __init media5200_probe(void)
251 {
252 	unsigned long node = of_get_flat_dt_root();
253 	int i = 0;
254 
255 	while (board[i]) {
256 		if (of_flat_dt_is_compatible(node, board[i]))
257 			break;
258 		i++;
259 	}
260 
261 	return (board[i] != NULL);
262 }
263 
264 define_machine(media5200_platform) {
265 	.name		= "media5200-platform",
266 	.probe		= media5200_probe,
267 	.setup_arch	= media5200_setup_arch,
268 	.init		= mpc52xx_declare_of_platform_devices,
269 	.init_IRQ	= media5200_init_irq,
270 	.get_irq	= mpc52xx_get_irq,
271 	.restart	= mpc52xx_restart,
272 	.calibrate_decr	= generic_calibrate_decr,
273 };
274