1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Support for 'media5200-platform' compatible boards.
4  *
5  * Copyright (C) 2008 Secret Lab Technologies Ltd.
6  *
7  * Description:
8  * This code implements support for the Freescape Media5200 platform
9  * (built around the MPC5200 SoC).
10  *
11  * Notable characteristic of the Media5200 is the presence of an FPGA
12  * that has all external IRQ lines routed through it.  This file implements
13  * a cascaded interrupt controller driver which attaches itself to the
14  * Virtual IRQ subsystem after the primary mpc5200 interrupt controller
15  * is initialized.
16  */
17 
18 #undef DEBUG
19 
20 #include <linux/irq.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <asm/time.h>
24 #include <asm/prom.h>
25 #include <asm/machdep.h>
26 #include <asm/mpc52xx.h>
27 
28 static const struct of_device_id mpc5200_gpio_ids[] __initconst = {
29 	{ .compatible = "fsl,mpc5200-gpio", },
30 	{ .compatible = "mpc5200-gpio", },
31 	{}
32 };
33 
34 /* FPGA register set */
35 #define MEDIA5200_IRQ_ENABLE (0x40c)
36 #define MEDIA5200_IRQ_STATUS (0x410)
37 #define MEDIA5200_NUM_IRQS   (6)
38 #define MEDIA5200_IRQ_SHIFT  (32 - MEDIA5200_NUM_IRQS)
39 
40 struct media5200_irq {
41 	void __iomem *regs;
42 	spinlock_t lock;
43 	struct irq_domain *irqhost;
44 };
45 struct media5200_irq media5200_irq;
46 
47 static void media5200_irq_unmask(struct irq_data *d)
48 {
49 	unsigned long flags;
50 	u32 val;
51 
52 	spin_lock_irqsave(&media5200_irq.lock, flags);
53 	val = in_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE);
54 	val |= 1 << (MEDIA5200_IRQ_SHIFT + irqd_to_hwirq(d));
55 	out_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE, val);
56 	spin_unlock_irqrestore(&media5200_irq.lock, flags);
57 }
58 
59 static void media5200_irq_mask(struct irq_data *d)
60 {
61 	unsigned long flags;
62 	u32 val;
63 
64 	spin_lock_irqsave(&media5200_irq.lock, flags);
65 	val = in_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE);
66 	val &= ~(1 << (MEDIA5200_IRQ_SHIFT + irqd_to_hwirq(d)));
67 	out_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE, val);
68 	spin_unlock_irqrestore(&media5200_irq.lock, flags);
69 }
70 
71 static struct irq_chip media5200_irq_chip = {
72 	.name = "Media5200 FPGA",
73 	.irq_unmask = media5200_irq_unmask,
74 	.irq_mask = media5200_irq_mask,
75 	.irq_mask_ack = media5200_irq_mask,
76 };
77 
78 static void media5200_irq_cascade(struct irq_desc *desc)
79 {
80 	struct irq_chip *chip = irq_desc_get_chip(desc);
81 	int sub_virq, val;
82 	u32 status, enable;
83 
84 	/* Mask off the cascaded IRQ */
85 	raw_spin_lock(&desc->lock);
86 	chip->irq_mask(&desc->irq_data);
87 	raw_spin_unlock(&desc->lock);
88 
89 	/* Ask the FPGA for IRQ status.  If 'val' is 0, then no irqs
90 	 * are pending.  'ffs()' is 1 based */
91 	status = in_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE);
92 	enable = in_be32(media5200_irq.regs + MEDIA5200_IRQ_STATUS);
93 	val = ffs((status & enable) >> MEDIA5200_IRQ_SHIFT);
94 	if (val) {
95 		sub_virq = irq_linear_revmap(media5200_irq.irqhost, val - 1);
96 		/* pr_debug("%s: virq=%i s=%.8x e=%.8x hwirq=%i subvirq=%i\n",
97 		 *          __func__, virq, status, enable, val - 1, sub_virq);
98 		 */
99 		generic_handle_irq(sub_virq);
100 	}
101 
102 	/* Processing done; can reenable the cascade now */
103 	raw_spin_lock(&desc->lock);
104 	chip->irq_ack(&desc->irq_data);
105 	if (!irqd_irq_disabled(&desc->irq_data))
106 		chip->irq_unmask(&desc->irq_data);
107 	raw_spin_unlock(&desc->lock);
108 }
109 
110 static int media5200_irq_map(struct irq_domain *h, unsigned int virq,
111 			     irq_hw_number_t hw)
112 {
113 	pr_debug("%s: h=%p, virq=%i, hwirq=%i\n", __func__, h, virq, (int)hw);
114 	irq_set_chip_data(virq, &media5200_irq);
115 	irq_set_chip_and_handler(virq, &media5200_irq_chip, handle_level_irq);
116 	irq_set_status_flags(virq, IRQ_LEVEL);
117 	return 0;
118 }
119 
120 static int media5200_irq_xlate(struct irq_domain *h, struct device_node *ct,
121 				 const u32 *intspec, unsigned int intsize,
122 				 irq_hw_number_t *out_hwirq,
123 				 unsigned int *out_flags)
124 {
125 	if (intsize != 2)
126 		return -1;
127 
128 	pr_debug("%s: bank=%i, number=%i\n", __func__, intspec[0], intspec[1]);
129 	*out_hwirq = intspec[1];
130 	*out_flags = IRQ_TYPE_NONE;
131 	return 0;
132 }
133 
134 static const struct irq_domain_ops media5200_irq_ops = {
135 	.map = media5200_irq_map,
136 	.xlate = media5200_irq_xlate,
137 };
138 
139 /*
140  * Setup Media5200 IRQ mapping
141  */
142 static void __init media5200_init_irq(void)
143 {
144 	struct device_node *fpga_np;
145 	int cascade_virq;
146 
147 	/* First setup the regular MPC5200 interrupt controller */
148 	mpc52xx_init_irq();
149 
150 	/* Now find the FPGA IRQ */
151 	fpga_np = of_find_compatible_node(NULL, NULL, "fsl,media5200-fpga");
152 	if (!fpga_np)
153 		goto out;
154 	pr_debug("%s: found fpga node: %pOF\n", __func__, fpga_np);
155 
156 	media5200_irq.regs = of_iomap(fpga_np, 0);
157 	if (!media5200_irq.regs)
158 		goto out;
159 	pr_debug("%s: mapped to %p\n", __func__, media5200_irq.regs);
160 
161 	cascade_virq = irq_of_parse_and_map(fpga_np, 0);
162 	if (!cascade_virq)
163 		goto out;
164 	pr_debug("%s: cascaded on virq=%i\n", __func__, cascade_virq);
165 
166 	/* Disable all FPGA IRQs */
167 	out_be32(media5200_irq.regs + MEDIA5200_IRQ_ENABLE, 0);
168 
169 	spin_lock_init(&media5200_irq.lock);
170 
171 	media5200_irq.irqhost = irq_domain_add_linear(fpga_np,
172 			MEDIA5200_NUM_IRQS, &media5200_irq_ops, &media5200_irq);
173 	if (!media5200_irq.irqhost)
174 		goto out;
175 	pr_debug("%s: allocated irqhost\n", __func__);
176 
177 	irq_set_handler_data(cascade_virq, &media5200_irq);
178 	irq_set_chained_handler(cascade_virq, media5200_irq_cascade);
179 
180 	return;
181 
182  out:
183 	pr_err("Could not find Media5200 FPGA; PCI interrupts will not work\n");
184 }
185 
186 /*
187  * Setup the architecture
188  */
189 static void __init media5200_setup_arch(void)
190 {
191 
192 	struct device_node *np;
193 	struct mpc52xx_gpio __iomem *gpio;
194 	u32 port_config;
195 
196 	if (ppc_md.progress)
197 		ppc_md.progress("media5200_setup_arch()", 0);
198 
199 	/* Map important registers from the internal memory map */
200 	mpc52xx_map_common_devices();
201 
202 	/* Some mpc5200 & mpc5200b related configuration */
203 	mpc5200_setup_xlb_arbiter();
204 
205 	mpc52xx_setup_pci();
206 
207 	np = of_find_matching_node(NULL, mpc5200_gpio_ids);
208 	gpio = of_iomap(np, 0);
209 	of_node_put(np);
210 	if (!gpio) {
211 		printk(KERN_ERR "%s() failed. expect abnormal behavior\n",
212 		       __func__);
213 		return;
214 	}
215 
216 	/* Set port config */
217 	port_config = in_be32(&gpio->port_config);
218 
219 	port_config &= ~0x03000000;	/* ATA CS is on csb_4/5		*/
220 	port_config |=  0x01000000;
221 
222 	out_be32(&gpio->port_config, port_config);
223 
224 	/* Unmap zone */
225 	iounmap(gpio);
226 
227 }
228 
229 /* list of the supported boards */
230 static const char * const board[] __initconst = {
231 	"fsl,media5200",
232 	NULL
233 };
234 
235 /*
236  * Called very early, MMU is off, device-tree isn't unflattened
237  */
238 static int __init media5200_probe(void)
239 {
240 	return of_device_compatible_match(of_root, board);
241 }
242 
243 define_machine(media5200_platform) {
244 	.name		= "media5200-platform",
245 	.probe		= media5200_probe,
246 	.setup_arch	= media5200_setup_arch,
247 	.init		= mpc52xx_declare_of_platform_devices,
248 	.init_IRQ	= media5200_init_irq,
249 	.get_irq	= mpc52xx_get_irq,
250 	.restart	= mpc52xx_restart,
251 	.calibrate_decr	= generic_calibrate_decr,
252 };
253