xref: /openbmc/linux/drivers/gpio/gpio-sodaville.c (revision 293d5b43)
1 /*
2  *  GPIO interface for Intel Sodaville SoCs.
3  *
4  *  Copyright (c) 2010, 2011 Intel Corporation
5  *
6  *  Author: Hans J. Koch <hjk@linutronix.de>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License 2 as published
10  *  by the Free Software Foundation.
11  *
12  */
13 
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/interrupt.h>
19 #include <linux/kernel.h>
20 #include <linux/pci.h>
21 #include <linux/platform_device.h>
22 #include <linux/of_irq.h>
23 #include <linux/gpio/driver.h>
24 
25 #define DRV_NAME		"sdv_gpio"
26 #define SDV_NUM_PUB_GPIOS	12
27 #define PCI_DEVICE_ID_SDV_GPIO	0x2e67
28 #define GPIO_BAR		0
29 
30 #define GPOUTR		0x00
31 #define GPOER		0x04
32 #define GPINR		0x08
33 
34 #define GPSTR		0x0c
35 #define GPIT1R0		0x10
36 #define GPIO_INT	0x14
37 #define GPIT1R1		0x18
38 
39 #define GPMUXCTL	0x1c
40 
41 struct sdv_gpio_chip_data {
42 	int irq_base;
43 	void __iomem *gpio_pub_base;
44 	struct irq_domain *id;
45 	struct irq_chip_generic *gc;
46 	struct gpio_chip chip;
47 };
48 
49 static int sdv_gpio_pub_set_type(struct irq_data *d, unsigned int type)
50 {
51 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
52 	struct sdv_gpio_chip_data *sd = gc->private;
53 	void __iomem *type_reg;
54 	u32 reg;
55 
56 	if (d->hwirq < 8)
57 		type_reg = sd->gpio_pub_base + GPIT1R0;
58 	else
59 		type_reg = sd->gpio_pub_base + GPIT1R1;
60 
61 	reg = readl(type_reg);
62 
63 	switch (type) {
64 	case IRQ_TYPE_LEVEL_HIGH:
65 		reg &= ~BIT(4 * (d->hwirq % 8));
66 		break;
67 
68 	case IRQ_TYPE_LEVEL_LOW:
69 		reg |= BIT(4 * (d->hwirq % 8));
70 		break;
71 
72 	default:
73 		return -EINVAL;
74 	}
75 
76 	writel(reg, type_reg);
77 	return 0;
78 }
79 
80 static irqreturn_t sdv_gpio_pub_irq_handler(int irq, void *data)
81 {
82 	struct sdv_gpio_chip_data *sd = data;
83 	u32 irq_stat = readl(sd->gpio_pub_base + GPSTR);
84 
85 	irq_stat &= readl(sd->gpio_pub_base + GPIO_INT);
86 	if (!irq_stat)
87 		return IRQ_NONE;
88 
89 	while (irq_stat) {
90 		u32 irq_bit = __fls(irq_stat);
91 
92 		irq_stat &= ~BIT(irq_bit);
93 		generic_handle_irq(irq_find_mapping(sd->id, irq_bit));
94 	}
95 
96 	return IRQ_HANDLED;
97 }
98 
99 static int sdv_xlate(struct irq_domain *h, struct device_node *node,
100 		const u32 *intspec, u32 intsize, irq_hw_number_t *out_hwirq,
101 		u32 *out_type)
102 {
103 	u32 line, type;
104 
105 	if (node != irq_domain_get_of_node(h))
106 		return -EINVAL;
107 
108 	if (intsize < 2)
109 		return -EINVAL;
110 
111 	line = *intspec;
112 	*out_hwirq = line;
113 
114 	intspec++;
115 	type = *intspec;
116 
117 	switch (type) {
118 	case IRQ_TYPE_LEVEL_LOW:
119 	case IRQ_TYPE_LEVEL_HIGH:
120 		*out_type = type;
121 		break;
122 	default:
123 		return -EINVAL;
124 	}
125 	return 0;
126 }
127 
128 static const struct irq_domain_ops irq_domain_sdv_ops = {
129 	.xlate = sdv_xlate,
130 };
131 
132 static int sdv_register_irqsupport(struct sdv_gpio_chip_data *sd,
133 		struct pci_dev *pdev)
134 {
135 	struct irq_chip_type *ct;
136 	int ret;
137 
138 	sd->irq_base = irq_alloc_descs(-1, 0, SDV_NUM_PUB_GPIOS, -1);
139 	if (sd->irq_base < 0)
140 		return sd->irq_base;
141 
142 	/* mask + ACK all interrupt sources */
143 	writel(0, sd->gpio_pub_base + GPIO_INT);
144 	writel((1 << 11) - 1, sd->gpio_pub_base + GPSTR);
145 
146 	ret = request_irq(pdev->irq, sdv_gpio_pub_irq_handler, IRQF_SHARED,
147 			"sdv_gpio", sd);
148 	if (ret)
149 		goto out_free_desc;
150 
151 	/*
152 	 * This gpio irq controller latches level irqs. Testing shows that if
153 	 * we unmask & ACK the IRQ before the source of the interrupt is gone
154 	 * then the interrupt is active again.
155 	 */
156 	sd->gc = irq_alloc_generic_chip("sdv-gpio", 1, sd->irq_base,
157 			sd->gpio_pub_base, handle_fasteoi_irq);
158 	if (!sd->gc) {
159 		ret = -ENOMEM;
160 		goto out_free_irq;
161 	}
162 
163 	sd->gc->private = sd;
164 	ct = sd->gc->chip_types;
165 	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
166 	ct->regs.eoi = GPSTR;
167 	ct->regs.mask = GPIO_INT;
168 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
169 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
170 	ct->chip.irq_eoi = irq_gc_eoi;
171 	ct->chip.irq_set_type = sdv_gpio_pub_set_type;
172 
173 	irq_setup_generic_chip(sd->gc, IRQ_MSK(SDV_NUM_PUB_GPIOS),
174 			IRQ_GC_INIT_MASK_CACHE, IRQ_NOREQUEST,
175 			IRQ_LEVEL | IRQ_NOPROBE);
176 
177 	sd->id = irq_domain_add_legacy(pdev->dev.of_node, SDV_NUM_PUB_GPIOS,
178 				sd->irq_base, 0, &irq_domain_sdv_ops, sd);
179 	if (!sd->id) {
180 		ret = -ENODEV;
181 		goto out_free_irq;
182 	}
183 	return 0;
184 out_free_irq:
185 	free_irq(pdev->irq, sd);
186 out_free_desc:
187 	irq_free_descs(sd->irq_base, SDV_NUM_PUB_GPIOS);
188 	return ret;
189 }
190 
191 static int sdv_gpio_probe(struct pci_dev *pdev,
192 					const struct pci_device_id *pci_id)
193 {
194 	struct sdv_gpio_chip_data *sd;
195 	unsigned long addr;
196 	const void *prop;
197 	int len;
198 	int ret;
199 	u32 mux_val;
200 
201 	sd = kzalloc(sizeof(struct sdv_gpio_chip_data), GFP_KERNEL);
202 	if (!sd)
203 		return -ENOMEM;
204 	ret = pci_enable_device(pdev);
205 	if (ret) {
206 		dev_err(&pdev->dev, "can't enable device.\n");
207 		goto done;
208 	}
209 
210 	ret = pci_request_region(pdev, GPIO_BAR, DRV_NAME);
211 	if (ret) {
212 		dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
213 		goto disable_pci;
214 	}
215 
216 	addr = pci_resource_start(pdev, GPIO_BAR);
217 	if (!addr) {
218 		ret = -ENODEV;
219 		goto release_reg;
220 	}
221 	sd->gpio_pub_base = ioremap(addr, pci_resource_len(pdev, GPIO_BAR));
222 
223 	prop = of_get_property(pdev->dev.of_node, "intel,muxctl", &len);
224 	if (prop && len == 4) {
225 		mux_val = of_read_number(prop, 1);
226 		writel(mux_val, sd->gpio_pub_base + GPMUXCTL);
227 	}
228 
229 	ret = bgpio_init(&sd->chip, &pdev->dev, 4,
230 			sd->gpio_pub_base + GPINR, sd->gpio_pub_base + GPOUTR,
231 			NULL, sd->gpio_pub_base + GPOER, NULL, 0);
232 	if (ret)
233 		goto unmap;
234 	sd->chip.ngpio = SDV_NUM_PUB_GPIOS;
235 
236 	ret = gpiochip_add_data(&sd->chip, sd);
237 	if (ret < 0) {
238 		dev_err(&pdev->dev, "gpiochip_add() failed.\n");
239 		goto unmap;
240 	}
241 
242 	ret = sdv_register_irqsupport(sd, pdev);
243 	if (ret)
244 		goto unmap;
245 
246 	pci_set_drvdata(pdev, sd);
247 	dev_info(&pdev->dev, "Sodaville GPIO driver registered.\n");
248 	return 0;
249 
250 unmap:
251 	iounmap(sd->gpio_pub_base);
252 release_reg:
253 	pci_release_region(pdev, GPIO_BAR);
254 disable_pci:
255 	pci_disable_device(pdev);
256 done:
257 	kfree(sd);
258 	return ret;
259 }
260 
261 static const struct pci_device_id sdv_gpio_pci_ids[] = {
262 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_SDV_GPIO) },
263 	{ 0, },
264 };
265 
266 static struct pci_driver sdv_gpio_driver = {
267 	.driver = {
268 		.suppress_bind_attrs = true,
269 	},
270 	.name = DRV_NAME,
271 	.id_table = sdv_gpio_pci_ids,
272 	.probe = sdv_gpio_probe,
273 };
274 builtin_pci_driver(sdv_gpio_driver);
275