summaryrefslogtreecommitdiffstats
path: root/drivers/irqchip/irq-ls-scfg-msi.c
blob: 02cca74cab943b5868c90b2decefa902dbc04f47 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
/*
 * Freescale SCFG MSI(-X) support
 *
 * Copyright (C) 2016 Freescale Semiconductor.
 *
 * Author: Minghuan Lian <Minghuan.Lian@nxp.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/msi.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
#include <linux/spinlock.h>

#define MSI_MAX_IRQS	32
#define MSI_IBS_SHIFT	3
#define MSIR		4

struct ls_scfg_msi {
	spinlock_t		lock;
	struct platform_device	*pdev;
	struct irq_domain	*parent;
	struct irq_domain	*msi_domain;
	void __iomem		*regs;
	phys_addr_t		msiir_addr;
	int			irq;
	DECLARE_BITMAP(used, MSI_MAX_IRQS);
};

static struct irq_chip ls_scfg_msi_irq_chip = {
	.name = "MSI",
	.irq_mask	= pci_msi_mask_irq,
	.irq_unmask	= pci_msi_unmask_irq,
};

static struct msi_domain_info ls_scfg_msi_domain_info = {
	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS |
		   MSI_FLAG_USE_DEF_CHIP_OPS |
		   MSI_FLAG_PCI_MSIX),
	.chip	= &ls_scfg_msi_irq_chip,
};

static void ls_scfg_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
{
	struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(data);

	msg->address_hi = upper_32_bits(msi_data->msiir_addr);
	msg->address_lo = lower_32_bits(msi_data->msiir_addr);
	msg->data = data->hwirq << MSI_IBS_SHIFT;
}

static int ls_scfg_msi_set_affinity(struct irq_data *irq_data,
				    const struct cpumask *mask, bool force)
{
	return -EINVAL;
}

static struct irq_chip ls_scfg_msi_parent_chip = {
	.name			= "SCFG",
	.irq_compose_msi_msg	= ls_scfg_msi_compose_msg,
	.irq_set_affinity	= ls_scfg_msi_set_affinity,
};

static int ls_scfg_msi_domain_irq_alloc(struct irq_domain *domain,
					unsigned int virq,
					unsigned int nr_irqs,
					void *args)
{
	struct ls_scfg_msi *msi_data = domain->host_data;
	int pos, err = 0;

	WARN_ON(nr_irqs != 1);

	spin_lock(&msi_data->lock);
	pos = find_first_zero_bit(msi_data->used, MSI_MAX_IRQS);
	if (pos < MSI_MAX_IRQS)
		__set_bit(pos, msi_data->used);
	else
		err = -ENOSPC;
	spin_unlock(&msi_data->lock);

	if (err)
		return err;

	irq_domain_set_info(domain, virq, pos,
			    &ls_scfg_msi_parent_chip, msi_data,
			    handle_simple_irq, NULL, NULL);

	return 0;
}

static void ls_scfg_msi_domain_irq_free(struct irq_domain *domain,
				   unsigned int virq, unsigned int nr_irqs)
{
	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
	struct ls_scfg_msi *msi_data = irq_data_get_irq_chip_data(d);
	int pos;

	pos = d->hwirq;
	if (pos < 0 || pos >= MSI_MAX_IRQS) {
		pr_err("failed to teardown msi. Invalid hwirq %d\n", pos);
		return;
	}

	spin_lock(&msi_data->lock);
	__clear_bit(pos, msi_data->used);
	spin_unlock(&msi_data->lock);
}

static const struct irq_domain_ops ls_scfg_msi_domain_ops = {
	.alloc	= ls_scfg_msi_domain_irq_alloc,
	.free	= ls_scfg_msi_domain_irq_free,
};

static void ls_scfg_msi_irq_handler(struct irq_desc *desc)
{
	struct ls_scfg_msi *msi_data = irq_desc_get_handler_data(desc);
	unsigned long val;
	int pos, virq;

	chained_irq_enter(irq_desc_get_chip(desc), desc);

	val = ioread32be(msi_data->regs + MSIR);
	for_each_set_bit(pos, &val, MSI_MAX_IRQS) {
		virq = irq_find_mapping(msi_data->parent, (31 - pos));
		if (virq)
			generic_handle_irq(virq);
	}

	chained_irq_exit(irq_desc_get_chip(desc), desc);
}

static int ls_scfg_msi_domains_init(struct ls_scfg_msi *msi_data)
{
	/* Initialize MSI domain parent */
	msi_data->parent = irq_domain_add_linear(NULL,
						 MSI_MAX_IRQS,
						 &ls_scfg_msi_domain_ops,
						 msi_data);
	if (!msi_data->parent) {
		dev_err(&msi_data->pdev->dev, "failed to create IRQ domain\n");
		return -ENOMEM;
	}

	msi_data->msi_domain = pci_msi_create_irq_domain(
				of_node_to_fwnode(msi_data->pdev->dev.of_node),
				&ls_scfg_msi_domain_info,
				msi_data->parent);
	if (!msi_data->msi_domain) {
		dev_err(&msi_data->pdev->dev, "failed to create MSI domain\n");
		irq_domain_remove(msi_data->parent);
		return -ENOMEM;
	}

	return 0;
}

static int ls_scfg_msi_probe(struct platform_device *pdev)
{
	struct ls_scfg_msi *msi_data;
	struct resource *res;
	int ret;

	msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
	if (!msi_data)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	msi_data->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(msi_data->regs)) {
		dev_err(&pdev->dev, "failed to initialize 'regs'\n");
		return PTR_ERR(msi_data->regs);
	}
	msi_data->msiir_addr = res->start;

	msi_data->irq = platform_get_irq(pdev, 0);
	if (msi_data->irq <= 0) {
		dev_err(&pdev->dev, "failed to get MSI irq\n");
		return -ENODEV;
	}

	msi_data->pdev = pdev;
	spin_lock_init(&msi_data->lock);

	ret = ls_scfg_msi_domains_init(msi_data);
	if (ret)
		return ret;

	irq_set_chained_handler_and_data(msi_data->irq,
					 ls_scfg_msi_irq_handler,
					 msi_data);

	platform_set_drvdata(pdev, msi_data);

	return 0;
}

static int ls_scfg_msi_remove(struct platform_device *pdev)
{
	struct ls_scfg_msi *msi_data = platform_get_drvdata(pdev);

	irq_set_chained_handler_and_data(msi_data->irq, NULL, NULL);

	irq_domain_remove(msi_data->msi_domain);
	irq_domain_remove(msi_data->parent);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

static const struct of_device_id ls_scfg_msi_id[] = {
	{ .compatible = "fsl,1s1021a-msi", },
	{ .compatible = "fsl,1s1043a-msi", },
	{},
};

static struct platform_driver ls_scfg_msi_driver = {
	.driver = {
		.name = "ls-scfg-msi",
		.of_match_table = ls_scfg_msi_id,
	},
	.probe = ls_scfg_msi_probe,
	.remove = ls_scfg_msi_remove,
};

module_platform_driver(ls_scfg_msi_driver);

MODULE_AUTHOR("Minghuan Lian <Minghuan.Lian@nxp.com>");
MODULE_DESCRIPTION("Freescale Layerscape SCFG MSI controller driver");
MODULE_LICENSE("GPL v2");