1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  GPIO interface for Intel Sodaville SoCs.
4  *
5  *  Copyright (c) 2010, 2011 Intel Corporation
6  *
7  *  Author: Hans J. Koch <hjk@linutronix.de>
8  */
9 
10 #include <linux/errno.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/kernel.h>
17 #include <linux/of_irq.h>
18 #include <linux/pci.h>
19 #include <linux/platform_device.h>
20 
21 #define DRV_NAME		"sdv_gpio"
22 #define SDV_NUM_PUB_GPIOS	12
23 #define PCI_DEVICE_ID_SDV_GPIO	0x2e67
24 #define GPIO_BAR		0
25 
26 #define GPOUTR		0x00
27 #define GPOER		0x04
28 #define GPINR		0x08
29 
30 #define GPSTR		0x0c
31 #define GPIT1R0		0x10
32 #define GPIO_INT	0x14
33 #define GPIT1R1		0x18
34 
35 #define GPMUXCTL	0x1c
36 
37 struct sdv_gpio_chip_data {
38 	int irq_base;
39 	void __iomem *gpio_pub_base;
40 	struct irq_domain *id;
41 	struct irq_chip_generic *gc;
42 	struct gpio_chip chip;
43 };
44 
sdv_gpio_pub_set_type(struct irq_data * d,unsigned int type)45 static int sdv_gpio_pub_set_type(struct irq_data *d, unsigned int type)
46 {
47 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
48 	struct sdv_gpio_chip_data *sd = gc->private;
49 	void __iomem *type_reg;
50 	u32 reg;
51 
52 	if (d->hwirq < 8)
53 		type_reg = sd->gpio_pub_base + GPIT1R0;
54 	else
55 		type_reg = sd->gpio_pub_base + GPIT1R1;
56 
57 	reg = readl(type_reg);
58 
59 	switch (type) {
60 	case IRQ_TYPE_LEVEL_HIGH:
61 		reg &= ~BIT(4 * (d->hwirq % 8));
62 		break;
63 
64 	case IRQ_TYPE_LEVEL_LOW:
65 		reg |= BIT(4 * (d->hwirq % 8));
66 		break;
67 
68 	default:
69 		return -EINVAL;
70 	}
71 
72 	writel(reg, type_reg);
73 	return 0;
74 }
75 
sdv_gpio_pub_irq_handler(int irq,void * data)76 static irqreturn_t sdv_gpio_pub_irq_handler(int irq, void *data)
77 {
78 	struct sdv_gpio_chip_data *sd = data;
79 	unsigned long irq_stat = readl(sd->gpio_pub_base + GPSTR);
80 	int irq_bit;
81 
82 	irq_stat &= readl(sd->gpio_pub_base + GPIO_INT);
83 	if (!irq_stat)
84 		return IRQ_NONE;
85 
86 	for_each_set_bit(irq_bit, &irq_stat, 32)
87 		generic_handle_domain_irq(sd->id, irq_bit);
88 
89 	return IRQ_HANDLED;
90 }
91 
sdv_xlate(struct irq_domain * h,struct device_node * node,const u32 * intspec,u32 intsize,irq_hw_number_t * out_hwirq,u32 * out_type)92 static int sdv_xlate(struct irq_domain *h, struct device_node *node,
93 		const u32 *intspec, u32 intsize, irq_hw_number_t *out_hwirq,
94 		u32 *out_type)
95 {
96 	u32 line, type;
97 
98 	if (node != irq_domain_get_of_node(h))
99 		return -EINVAL;
100 
101 	if (intsize < 2)
102 		return -EINVAL;
103 
104 	line = *intspec;
105 	*out_hwirq = line;
106 
107 	intspec++;
108 	type = *intspec;
109 
110 	switch (type) {
111 	case IRQ_TYPE_LEVEL_LOW:
112 	case IRQ_TYPE_LEVEL_HIGH:
113 		*out_type = type;
114 		break;
115 	default:
116 		return -EINVAL;
117 	}
118 	return 0;
119 }
120 
121 static const struct irq_domain_ops irq_domain_sdv_ops = {
122 	.xlate = sdv_xlate,
123 };
124 
sdv_register_irqsupport(struct sdv_gpio_chip_data * sd,struct pci_dev * pdev)125 static int sdv_register_irqsupport(struct sdv_gpio_chip_data *sd,
126 		struct pci_dev *pdev)
127 {
128 	struct irq_chip_type *ct;
129 	int ret;
130 
131 	sd->irq_base = devm_irq_alloc_descs(&pdev->dev, -1, 0,
132 					    SDV_NUM_PUB_GPIOS, -1);
133 	if (sd->irq_base < 0)
134 		return sd->irq_base;
135 
136 	/* mask + ACK all interrupt sources */
137 	writel(0, sd->gpio_pub_base + GPIO_INT);
138 	writel((1 << 11) - 1, sd->gpio_pub_base + GPSTR);
139 
140 	ret = devm_request_irq(&pdev->dev, pdev->irq,
141 			       sdv_gpio_pub_irq_handler, IRQF_SHARED,
142 			       "sdv_gpio", sd);
143 	if (ret)
144 		return ret;
145 
146 	/*
147 	 * This gpio irq controller latches level irqs. Testing shows that if
148 	 * we unmask & ACK the IRQ before the source of the interrupt is gone
149 	 * then the interrupt is active again.
150 	 */
151 	sd->gc = devm_irq_alloc_generic_chip(&pdev->dev, "sdv-gpio", 1,
152 					     sd->irq_base,
153 					     sd->gpio_pub_base,
154 					     handle_fasteoi_irq);
155 	if (!sd->gc)
156 		return -ENOMEM;
157 
158 	sd->gc->private = sd;
159 	ct = sd->gc->chip_types;
160 	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
161 	ct->regs.eoi = GPSTR;
162 	ct->regs.mask = GPIO_INT;
163 	ct->chip.irq_mask = irq_gc_mask_clr_bit;
164 	ct->chip.irq_unmask = irq_gc_mask_set_bit;
165 	ct->chip.irq_eoi = irq_gc_eoi;
166 	ct->chip.irq_set_type = sdv_gpio_pub_set_type;
167 
168 	irq_setup_generic_chip(sd->gc, IRQ_MSK(SDV_NUM_PUB_GPIOS),
169 			IRQ_GC_INIT_MASK_CACHE, IRQ_NOREQUEST,
170 			IRQ_LEVEL | IRQ_NOPROBE);
171 
172 	sd->id = irq_domain_add_legacy(pdev->dev.of_node, SDV_NUM_PUB_GPIOS,
173 				sd->irq_base, 0, &irq_domain_sdv_ops, sd);
174 	if (!sd->id)
175 		return -ENODEV;
176 
177 	return 0;
178 }
179 
sdv_gpio_probe(struct pci_dev * pdev,const struct pci_device_id * pci_id)180 static int sdv_gpio_probe(struct pci_dev *pdev,
181 					const struct pci_device_id *pci_id)
182 {
183 	struct sdv_gpio_chip_data *sd;
184 	int ret;
185 	u32 mux_val;
186 
187 	sd = devm_kzalloc(&pdev->dev, sizeof(*sd), GFP_KERNEL);
188 	if (!sd)
189 		return -ENOMEM;
190 
191 	ret = pcim_enable_device(pdev);
192 	if (ret) {
193 		dev_err(&pdev->dev, "can't enable device.\n");
194 		return ret;
195 	}
196 
197 	ret = pcim_iomap_regions(pdev, 1 << GPIO_BAR, DRV_NAME);
198 	if (ret) {
199 		dev_err(&pdev->dev, "can't alloc PCI BAR #%d\n", GPIO_BAR);
200 		return ret;
201 	}
202 
203 	sd->gpio_pub_base = pcim_iomap_table(pdev)[GPIO_BAR];
204 
205 	ret = of_property_read_u32(pdev->dev.of_node, "intel,muxctl", &mux_val);
206 	if (!ret)
207 		writel(mux_val, sd->gpio_pub_base + GPMUXCTL);
208 
209 	ret = bgpio_init(&sd->chip, &pdev->dev, 4,
210 			sd->gpio_pub_base + GPINR, sd->gpio_pub_base + GPOUTR,
211 			NULL, sd->gpio_pub_base + GPOER, NULL, 0);
212 	if (ret)
213 		return ret;
214 
215 	sd->chip.ngpio = SDV_NUM_PUB_GPIOS;
216 
217 	ret = devm_gpiochip_add_data(&pdev->dev, &sd->chip, sd);
218 	if (ret < 0) {
219 		dev_err(&pdev->dev, "gpiochip_add() failed.\n");
220 		return ret;
221 	}
222 
223 	ret = sdv_register_irqsupport(sd, pdev);
224 	if (ret)
225 		return ret;
226 
227 	pci_set_drvdata(pdev, sd);
228 	dev_info(&pdev->dev, "Sodaville GPIO driver registered.\n");
229 	return 0;
230 }
231 
232 static const struct pci_device_id sdv_gpio_pci_ids[] = {
233 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_SDV_GPIO) },
234 	{ 0, },
235 };
236 
237 static struct pci_driver sdv_gpio_driver = {
238 	.driver = {
239 		.suppress_bind_attrs = true,
240 	},
241 	.name = DRV_NAME,
242 	.id_table = sdv_gpio_pci_ids,
243 	.probe = sdv_gpio_probe,
244 };
245 builtin_pci_driver(sdv_gpio_driver);
246