1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Abilis Systems MODULE DESCRIPTION
3 *
4 * Copyright (C) Abilis Systems 2013
5 *
6 * Authors: Sascha Leuenberger <sascha.leuenberger@abilis.com>
7 * Christian Ruppert <christian.ruppert@abilis.com>
8 */
9
10 #include <linux/bitops.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/gpio/generic.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_platform.h>
21 #include <linux/pinctrl/consumer.h>
22 #include <linux/platform_device.h>
23 #include <linux/slab.h>
24
25 #define TB10X_GPIO_DIR_IN (0x00000000)
26 #define TB10X_GPIO_DIR_OUT (0x00000001)
27 #define OFFSET_TO_REG_DDR (0x00)
28 #define OFFSET_TO_REG_DATA (0x04)
29 #define OFFSET_TO_REG_INT_EN (0x08)
30 #define OFFSET_TO_REG_CHANGE (0x0C)
31 #define OFFSET_TO_REG_WRMASK (0x10)
32 #define OFFSET_TO_REG_INT_TYPE (0x14)
33
34
35 /**
36 * struct tb10x_gpio - TB10x GPIO controller structure
37 * @base: register base address
38 * @domain: IRQ domain of GPIO generated interrupts managed by this controller
39 * @irq: Interrupt line of parent interrupt controller
40 * @chip: Generic GPIO chip structure associated with this GPIO controller
41 */
42 struct tb10x_gpio {
43 void __iomem *base;
44 struct irq_domain *domain;
45 int irq;
46 struct gpio_generic_chip chip;
47 };
48
tb10x_reg_read(struct tb10x_gpio * gpio,unsigned int offs)49 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
50 {
51 return ioread32(gpio->base + offs);
52 }
53
tb10x_gpio_to_irq(struct gpio_chip * chip,unsigned int offset)54 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
55 {
56 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
57
58 return irq_create_mapping(tb10x_gpio->domain, offset);
59 }
60
tb10x_gpio_irq_set_type(struct irq_data * data,unsigned int type)61 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
62 {
63 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
64 pr_err("Only (both) edge triggered interrupts supported.\n");
65 return -EINVAL;
66 }
67
68 irqd_set_trigger_type(data, type);
69
70 return IRQ_SET_MASK_OK;
71 }
72
tb10x_gpio_irq_cascade(int irq,void * data)73 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
74 {
75 struct tb10x_gpio *tb10x_gpio = data;
76 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
77 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
78 const unsigned long bits = r & m;
79 int i;
80
81 for_each_set_bit(i, &bits, 32)
82 generic_handle_domain_irq(tb10x_gpio->domain, i);
83
84 return IRQ_HANDLED;
85 }
86
tb10x_gpio_probe(struct platform_device * pdev)87 static int tb10x_gpio_probe(struct platform_device *pdev)
88 {
89 struct gpio_generic_chip_config config;
90 struct tb10x_gpio *tb10x_gpio;
91 struct device *dev = &pdev->dev;
92 struct device_node *np = dev->of_node;
93 int ret = -EBUSY;
94 u32 ngpio;
95
96 if (!np)
97 return -EINVAL;
98
99 if (of_property_read_u32(np, "abilis,ngpio", &ngpio))
100 return -EINVAL;
101
102 tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL);
103 if (tb10x_gpio == NULL)
104 return -ENOMEM;
105
106 tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0);
107 if (IS_ERR(tb10x_gpio->base))
108 return PTR_ERR(tb10x_gpio->base);
109
110 tb10x_gpio->chip.gc.label =
111 devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
112 if (!tb10x_gpio->chip.gc.label)
113 return -ENOMEM;
114
115 /*
116 * Initialize generic GPIO with one single register for reading and setting
117 * the lines, no special set or clear registers and a data direction register
118 * wher 1 means "output".
119 */
120 config = (struct gpio_generic_chip_config) {
121 .dev = dev,
122 .sz = 4,
123 .dat = tb10x_gpio->base + OFFSET_TO_REG_DATA,
124 .dirout = tb10x_gpio->base + OFFSET_TO_REG_DDR,
125 };
126
127 ret = gpio_generic_chip_init(&tb10x_gpio->chip, &config);
128 if (ret) {
129 dev_err(dev, "unable to init generic GPIO\n");
130 return ret;
131 }
132 tb10x_gpio->chip.gc.base = -1;
133 tb10x_gpio->chip.gc.parent = dev;
134 tb10x_gpio->chip.gc.owner = THIS_MODULE;
135 /*
136 * ngpio is set by gpio_generic_chip_init() but we override it, this
137 * .request() callback also overrides the one set up by generic GPIO.
138 */
139 tb10x_gpio->chip.gc.ngpio = ngpio;
140 tb10x_gpio->chip.gc.request = gpiochip_generic_request;
141 tb10x_gpio->chip.gc.free = gpiochip_generic_free;
142
143 ret = devm_gpiochip_add_data(dev, &tb10x_gpio->chip.gc, tb10x_gpio);
144 if (ret < 0) {
145 dev_err(dev, "Could not add gpiochip.\n");
146 return ret;
147 }
148
149 platform_set_drvdata(pdev, tb10x_gpio);
150
151 if (of_property_read_bool(np, "interrupt-controller")) {
152 struct irq_chip_generic *gc;
153
154 ret = platform_get_irq(pdev, 0);
155 if (ret < 0)
156 return ret;
157
158 tb10x_gpio->chip.gc.to_irq = tb10x_gpio_to_irq;
159 tb10x_gpio->irq = ret;
160
161 ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade,
162 IRQF_TRIGGER_NONE | IRQF_SHARED,
163 dev_name(dev), tb10x_gpio);
164 if (ret != 0)
165 return ret;
166
167 tb10x_gpio->domain = irq_domain_create_linear(dev_fwnode(dev),
168 tb10x_gpio->chip.gc.ngpio,
169 &irq_generic_chip_ops, NULL);
170 if (!tb10x_gpio->domain)
171 return -ENOMEM;
172
173 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
174 tb10x_gpio->chip.gc.ngpio, 1, tb10x_gpio->chip.gc.label,
175 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
176 IRQ_GC_INIT_MASK_CACHE);
177 if (ret)
178 goto err_remove_domain;
179
180 gc = tb10x_gpio->domain->gc->gc[0];
181 gc->reg_base = tb10x_gpio->base;
182 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
183 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
184 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
185 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
186 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type;
187 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE;
188 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN;
189 }
190
191 return 0;
192
193 err_remove_domain:
194 irq_domain_remove(tb10x_gpio->domain);
195 return ret;
196 }
197
tb10x_gpio_remove(struct platform_device * pdev)198 static void tb10x_gpio_remove(struct platform_device *pdev)
199 {
200 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
201
202 if (tb10x_gpio->chip.gc.to_irq) {
203 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
204 BIT(tb10x_gpio->chip.gc.ngpio) - 1, 0, 0);
205 kfree(tb10x_gpio->domain->gc);
206 irq_domain_remove(tb10x_gpio->domain);
207 }
208 }
209
210 static const struct of_device_id tb10x_gpio_dt_ids[] = {
211 { .compatible = "abilis,tb10x-gpio" },
212 { }
213 };
214 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
215
216 static struct platform_driver tb10x_gpio_driver = {
217 .probe = tb10x_gpio_probe,
218 .remove = tb10x_gpio_remove,
219 .driver = {
220 .name = "tb10x-gpio",
221 .of_match_table = tb10x_gpio_dt_ids,
222 }
223 };
224
225 module_platform_driver(tb10x_gpio_driver);
226 MODULE_LICENSE("GPL");
227 MODULE_DESCRIPTION("tb10x gpio.");
228