1 /*
2  * Copyright (C) 2017 Marvell
3  *
4  * Hanna Hawa <hannah@marvell.com>
5  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
6  *
7  * This file is licensed under the terms of the GNU General Public
8  * License version 2. This program is licensed "as is" without any
9  * warranty of any kind, whether express or implied.
10  */
11 
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/irqchip.h>
15 #include <linux/irqdomain.h>
16 #include <linux/kernel.h>
17 #include <linux/msi.h>
18 #include <linux/of_irq.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
21 
22 #include <dt-bindings/interrupt-controller/mvebu-icu.h>
23 
24 #include "irq-mvebu-gicp.h"
25 
26 /* ICU registers */
27 #define ICU_SETSPI_NSR_AL	0x10
28 #define ICU_SETSPI_NSR_AH	0x14
29 #define ICU_CLRSPI_NSR_AL	0x18
30 #define ICU_CLRSPI_NSR_AH	0x1c
31 #define ICU_INT_CFG(x)          (0x100 + 4 * (x))
32 #define   ICU_INT_ENABLE	BIT(24)
33 #define   ICU_IS_EDGE		BIT(28)
34 #define   ICU_GROUP_SHIFT	29
35 
36 /* ICU definitions */
37 #define ICU_MAX_IRQS		207
38 #define ICU_SATA0_ICU_ID	109
39 #define ICU_SATA1_ICU_ID	107
40 
41 struct mvebu_icu {
42 	struct irq_chip irq_chip;
43 	void __iomem *base;
44 	struct irq_domain *domain;
45 	struct device *dev;
46 };
47 
48 struct mvebu_icu_irq_data {
49 	struct mvebu_icu *icu;
50 	unsigned int icu_group;
51 	unsigned int type;
52 };
53 
54 static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
55 {
56 	struct irq_data *d = irq_get_irq_data(desc->irq);
57 	struct mvebu_icu_irq_data *icu_irqd = d->chip_data;
58 	struct mvebu_icu *icu = icu_irqd->icu;
59 	unsigned int icu_int;
60 
61 	if (msg->address_lo || msg->address_hi) {
62 		/* Configure the ICU with irq number & type */
63 		icu_int = msg->data | ICU_INT_ENABLE;
64 		if (icu_irqd->type & IRQ_TYPE_EDGE_RISING)
65 			icu_int |= ICU_IS_EDGE;
66 		icu_int |= icu_irqd->icu_group << ICU_GROUP_SHIFT;
67 	} else {
68 		/* De-configure the ICU */
69 		icu_int = 0;
70 	}
71 
72 	writel_relaxed(icu_int, icu->base + ICU_INT_CFG(d->hwirq));
73 
74 	/*
75 	 * The SATA unit has 2 ports, and a dedicated ICU entry per
76 	 * port. The ahci sata driver supports only one irq interrupt
77 	 * per SATA unit. To solve this conflict, we configure the 2
78 	 * SATA wired interrupts in the south bridge into 1 GIC
79 	 * interrupt in the north bridge. Even if only a single port
80 	 * is enabled, if sata node is enabled, both interrupts are
81 	 * configured (regardless of which port is actually in use).
82 	 */
83 	if (d->hwirq == ICU_SATA0_ICU_ID || d->hwirq == ICU_SATA1_ICU_ID) {
84 		writel_relaxed(icu_int,
85 			       icu->base + ICU_INT_CFG(ICU_SATA0_ICU_ID));
86 		writel_relaxed(icu_int,
87 			       icu->base + ICU_INT_CFG(ICU_SATA1_ICU_ID));
88 	}
89 }
90 
91 static int
92 mvebu_icu_irq_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
93 			       unsigned long *hwirq, unsigned int *type)
94 {
95 	struct mvebu_icu *icu = d->host_data;
96 	unsigned int icu_group;
97 
98 	/* Check the count of the parameters in dt */
99 	if (WARN_ON(fwspec->param_count < 3)) {
100 		dev_err(icu->dev, "wrong ICU parameter count %d\n",
101 			fwspec->param_count);
102 		return -EINVAL;
103 	}
104 
105 	/* Only ICU group type is handled */
106 	icu_group = fwspec->param[0];
107 	if (icu_group != ICU_GRP_NSR && icu_group != ICU_GRP_SR &&
108 	    icu_group != ICU_GRP_SEI && icu_group != ICU_GRP_REI) {
109 		dev_err(icu->dev, "wrong ICU group type %x\n", icu_group);
110 		return -EINVAL;
111 	}
112 
113 	*hwirq = fwspec->param[1];
114 	if (*hwirq >= ICU_MAX_IRQS) {
115 		dev_err(icu->dev, "invalid interrupt number %ld\n", *hwirq);
116 		return -EINVAL;
117 	}
118 
119 	/* Mask the type to prevent wrong DT configuration */
120 	*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
121 
122 	return 0;
123 }
124 
125 static int
126 mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
127 			   unsigned int nr_irqs, void *args)
128 {
129 	int err;
130 	unsigned long hwirq;
131 	struct irq_fwspec *fwspec = args;
132 	struct mvebu_icu *icu = platform_msi_get_host_data(domain);
133 	struct mvebu_icu_irq_data *icu_irqd;
134 
135 	icu_irqd = kmalloc(sizeof(*icu_irqd), GFP_KERNEL);
136 	if (!icu_irqd)
137 		return -ENOMEM;
138 
139 	err = mvebu_icu_irq_domain_translate(domain, fwspec, &hwirq,
140 					     &icu_irqd->type);
141 	if (err) {
142 		dev_err(icu->dev, "failed to translate ICU parameters\n");
143 		goto free_irqd;
144 	}
145 
146 	icu_irqd->icu_group = fwspec->param[0];
147 	icu_irqd->icu = icu;
148 
149 	err = platform_msi_domain_alloc(domain, virq, nr_irqs);
150 	if (err) {
151 		dev_err(icu->dev, "failed to allocate ICU interrupt in parent domain\n");
152 		goto free_irqd;
153 	}
154 
155 	/* Make sure there is no interrupt left pending by the firmware */
156 	err = irq_set_irqchip_state(virq, IRQCHIP_STATE_PENDING, false);
157 	if (err)
158 		goto free_msi;
159 
160 	err = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
161 					    &icu->irq_chip, icu_irqd);
162 	if (err) {
163 		dev_err(icu->dev, "failed to set the data to IRQ domain\n");
164 		goto free_msi;
165 	}
166 
167 	return 0;
168 
169 free_msi:
170 	platform_msi_domain_free(domain, virq, nr_irqs);
171 free_irqd:
172 	kfree(icu_irqd);
173 	return err;
174 }
175 
176 static void
177 mvebu_icu_irq_domain_free(struct irq_domain *domain, unsigned int virq,
178 			  unsigned int nr_irqs)
179 {
180 	struct irq_data *d = irq_get_irq_data(virq);
181 	struct mvebu_icu_irq_data *icu_irqd = d->chip_data;
182 
183 	kfree(icu_irqd);
184 
185 	platform_msi_domain_free(domain, virq, nr_irqs);
186 }
187 
188 static const struct irq_domain_ops mvebu_icu_domain_ops = {
189 	.translate = mvebu_icu_irq_domain_translate,
190 	.alloc     = mvebu_icu_irq_domain_alloc,
191 	.free      = mvebu_icu_irq_domain_free,
192 };
193 
194 static int mvebu_icu_probe(struct platform_device *pdev)
195 {
196 	struct mvebu_icu *icu;
197 	struct device_node *node = pdev->dev.of_node;
198 	struct device_node *gicp_dn;
199 	struct resource *res;
200 	phys_addr_t setspi, clrspi;
201 	u32 i, icu_int;
202 	int ret;
203 
204 	icu = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_icu),
205 			   GFP_KERNEL);
206 	if (!icu)
207 		return -ENOMEM;
208 
209 	icu->dev = &pdev->dev;
210 
211 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
212 	icu->base = devm_ioremap_resource(&pdev->dev, res);
213 	if (IS_ERR(icu->base)) {
214 		dev_err(&pdev->dev, "Failed to map icu base address.\n");
215 		return PTR_ERR(icu->base);
216 	}
217 
218 	icu->irq_chip.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
219 					    "ICU.%x",
220 					    (unsigned int)res->start);
221 	if (!icu->irq_chip.name)
222 		return -ENOMEM;
223 
224 	icu->irq_chip.irq_mask = irq_chip_mask_parent;
225 	icu->irq_chip.irq_unmask = irq_chip_unmask_parent;
226 	icu->irq_chip.irq_eoi = irq_chip_eoi_parent;
227 	icu->irq_chip.irq_set_type = irq_chip_set_type_parent;
228 #ifdef CONFIG_SMP
229 	icu->irq_chip.irq_set_affinity = irq_chip_set_affinity_parent;
230 #endif
231 
232 	/*
233 	 * We're probed after MSI domains have been resolved, so force
234 	 * resolution here.
235 	 */
236 	pdev->dev.msi_domain = of_msi_get_domain(&pdev->dev, node,
237 						 DOMAIN_BUS_PLATFORM_MSI);
238 	if (!pdev->dev.msi_domain)
239 		return -EPROBE_DEFER;
240 
241 	gicp_dn = irq_domain_get_of_node(pdev->dev.msi_domain);
242 	if (!gicp_dn)
243 		return -ENODEV;
244 
245 	ret = mvebu_gicp_get_doorbells(gicp_dn, &setspi, &clrspi);
246 	if (ret)
247 		return ret;
248 
249 	/* Set Clear/Set ICU SPI message address in AP */
250 	writel_relaxed(upper_32_bits(setspi), icu->base + ICU_SETSPI_NSR_AH);
251 	writel_relaxed(lower_32_bits(setspi), icu->base + ICU_SETSPI_NSR_AL);
252 	writel_relaxed(upper_32_bits(clrspi), icu->base + ICU_CLRSPI_NSR_AH);
253 	writel_relaxed(lower_32_bits(clrspi), icu->base + ICU_CLRSPI_NSR_AL);
254 
255 	/*
256 	 * Clean all ICU interrupts with type SPI_NSR, required to
257 	 * avoid unpredictable SPI assignments done by firmware.
258 	 */
259 	for (i = 0 ; i < ICU_MAX_IRQS ; i++) {
260 		icu_int = readl(icu->base + ICU_INT_CFG(i));
261 		if ((icu_int >> ICU_GROUP_SHIFT) == ICU_GRP_NSR)
262 			writel_relaxed(0x0, icu->base + ICU_INT_CFG(i));
263 	}
264 
265 	icu->domain =
266 		platform_msi_create_device_domain(&pdev->dev, ICU_MAX_IRQS,
267 						  mvebu_icu_write_msg,
268 						  &mvebu_icu_domain_ops, icu);
269 	if (!icu->domain) {
270 		dev_err(&pdev->dev, "Failed to create ICU domain\n");
271 		return -ENOMEM;
272 	}
273 
274 	return 0;
275 }
276 
277 static const struct of_device_id mvebu_icu_of_match[] = {
278 	{ .compatible = "marvell,cp110-icu", },
279 	{},
280 };
281 
282 static struct platform_driver mvebu_icu_driver = {
283 	.probe  = mvebu_icu_probe,
284 	.driver = {
285 		.name = "mvebu-icu",
286 		.of_match_table = mvebu_icu_of_match,
287 	},
288 };
289 builtin_platform_driver(mvebu_icu_driver);
290