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 * @base: register base address
37 * @domain: IRQ domain of GPIO generated interrupts managed by this controller
38 * @irq: Interrupt line of parent interrupt controller
39 * @chip: Generic GPIO chip structure associated with this GPIO controller
40 */
41 struct tb10x_gpio {
42 void __iomem *base;
43 struct irq_domain *domain;
44 int irq;
45 struct gpio_generic_chip chip;
46 };
47
tb10x_reg_read(struct tb10x_gpio * gpio,unsigned int offs)48 static inline u32 tb10x_reg_read(struct tb10x_gpio *gpio, unsigned int offs)
49 {
50 return ioread32(gpio->base + offs);
51 }
52
tb10x_gpio_to_irq(struct gpio_chip * chip,unsigned offset)53 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
54 {
55 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
56
57 return irq_create_mapping(tb10x_gpio->domain, offset);
58 }
59
tb10x_gpio_irq_set_type(struct irq_data * data,unsigned int type)60 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
61 {
62 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
63 pr_err("Only (both) edge triggered interrupts supported.\n");
64 return -EINVAL;
65 }
66
67 irqd_set_trigger_type(data, type);
68
69 return IRQ_SET_MASK_OK;
70 }
71
tb10x_gpio_irq_cascade(int irq,void * data)72 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
73 {
74 struct tb10x_gpio *tb10x_gpio = data;
75 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
76 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
77 const unsigned long bits = r & m;
78 int i;
79
80 for_each_set_bit(i, &bits, 32)
81 generic_handle_domain_irq(tb10x_gpio->domain, i);
82
83 return IRQ_HANDLED;
84 }
85
tb10x_gpio_probe(struct platform_device * pdev)86 static int tb10x_gpio_probe(struct platform_device *pdev)
87 {
88 struct gpio_generic_chip_config config;
89 struct tb10x_gpio *tb10x_gpio;
90 struct device *dev = &pdev->dev;
91 struct device_node *np = dev->of_node;
92 int ret = -EBUSY;
93 u32 ngpio;
94
95 if (!np)
96 return -EINVAL;
97
98 if (of_property_read_u32(np, "abilis,ngpio", &ngpio))
99 return -EINVAL;
100
101 tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL);
102 if (tb10x_gpio == NULL)
103 return -ENOMEM;
104
105 tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0);
106 if (IS_ERR(tb10x_gpio->base))
107 return PTR_ERR(tb10x_gpio->base);
108
109 tb10x_gpio->chip.gc.label =
110 devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
111 if (!tb10x_gpio->chip.gc.label)
112 return -ENOMEM;
113
114 /*
115 * Initialize generic GPIO with one single register for reading and setting
116 * the lines, no special set or clear registers and a data direction register
117 * wher 1 means "output".
118 */
119 config = (struct gpio_generic_chip_config) {
120 .dev = dev,
121 .sz = 4,
122 .dat = tb10x_gpio->base + OFFSET_TO_REG_DATA,
123 .dirout = tb10x_gpio->base + OFFSET_TO_REG_DDR,
124 };
125
126 ret = gpio_generic_chip_init(&tb10x_gpio->chip, &config);
127 if (ret) {
128 dev_err(dev, "unable to init generic GPIO\n");
129 return ret;
130 }
131 tb10x_gpio->chip.gc.base = -1;
132 tb10x_gpio->chip.gc.parent = dev;
133 tb10x_gpio->chip.gc.owner = THIS_MODULE;
134 /*
135 * ngpio is set by gpio_generic_chip_init() but we override it, this
136 * .request() callback also overrides the one set up by generic GPIO.
137 */
138 tb10x_gpio->chip.gc.ngpio = ngpio;
139 tb10x_gpio->chip.gc.request = gpiochip_generic_request;
140 tb10x_gpio->chip.gc.free = gpiochip_generic_free;
141
142 ret = devm_gpiochip_add_data(dev, &tb10x_gpio->chip.gc, tb10x_gpio);
143 if (ret < 0) {
144 dev_err(dev, "Could not add gpiochip.\n");
145 return ret;
146 }
147
148 platform_set_drvdata(pdev, tb10x_gpio);
149
150 if (of_property_read_bool(np, "interrupt-controller")) {
151 struct irq_chip_generic *gc;
152
153 ret = platform_get_irq(pdev, 0);
154 if (ret < 0)
155 return ret;
156
157 tb10x_gpio->chip.gc.to_irq = tb10x_gpio_to_irq;
158 tb10x_gpio->irq = ret;
159
160 ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade,
161 IRQF_TRIGGER_NONE | IRQF_SHARED,
162 dev_name(dev), tb10x_gpio);
163 if (ret != 0)
164 return ret;
165
166 tb10x_gpio->domain = irq_domain_create_linear(dev_fwnode(dev),
167 tb10x_gpio->chip.gc.ngpio,
168 &irq_generic_chip_ops, NULL);
169 if (!tb10x_gpio->domain) {
170 return -ENOMEM;
171 }
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