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/kernel.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/gpio/driver.h>
14 #include <linux/slab.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/of.h>
20 #include <linux/of_platform.h>
21 #include <linux/spinlock.h>
22 #include <linux/bitops.h>
23 #include <linux/pinctrl/consumer.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 * @gc: gpio_chip structure associated to this GPIO controller
40 */
41 struct tb10x_gpio {
42 void __iomem *base;
43 struct irq_domain *domain;
44 int irq;
45 struct gpio_chip gc;
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_reg_write(struct tb10x_gpio * gpio,unsigned int offs,u32 val)53 static inline void tb10x_reg_write(struct tb10x_gpio *gpio, unsigned int offs,
54 u32 val)
55 {
56 iowrite32(val, gpio->base + offs);
57 }
58
tb10x_set_bits(struct tb10x_gpio * gpio,unsigned int offs,u32 mask,u32 val)59 static inline void tb10x_set_bits(struct tb10x_gpio *gpio, unsigned int offs,
60 u32 mask, u32 val)
61 {
62 u32 r;
63 unsigned long flags;
64
65 spin_lock_irqsave(&gpio->gc.bgpio_lock, flags);
66
67 r = tb10x_reg_read(gpio, offs);
68 r = (r & ~mask) | (val & mask);
69
70 tb10x_reg_write(gpio, offs, r);
71
72 spin_unlock_irqrestore(&gpio->gc.bgpio_lock, flags);
73 }
74
tb10x_gpio_to_irq(struct gpio_chip * chip,unsigned offset)75 static int tb10x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
76 {
77 struct tb10x_gpio *tb10x_gpio = gpiochip_get_data(chip);
78
79 return irq_create_mapping(tb10x_gpio->domain, offset);
80 }
81
tb10x_gpio_irq_set_type(struct irq_data * data,unsigned int type)82 static int tb10x_gpio_irq_set_type(struct irq_data *data, unsigned int type)
83 {
84 if ((type & IRQF_TRIGGER_MASK) != IRQ_TYPE_EDGE_BOTH) {
85 pr_err("Only (both) edge triggered interrupts supported.\n");
86 return -EINVAL;
87 }
88
89 irqd_set_trigger_type(data, type);
90
91 return IRQ_SET_MASK_OK;
92 }
93
tb10x_gpio_irq_cascade(int irq,void * data)94 static irqreturn_t tb10x_gpio_irq_cascade(int irq, void *data)
95 {
96 struct tb10x_gpio *tb10x_gpio = data;
97 u32 r = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_CHANGE);
98 u32 m = tb10x_reg_read(tb10x_gpio, OFFSET_TO_REG_INT_EN);
99 const unsigned long bits = r & m;
100 int i;
101
102 for_each_set_bit(i, &bits, 32)
103 generic_handle_irq(irq_find_mapping(tb10x_gpio->domain, i));
104
105 return IRQ_HANDLED;
106 }
107
tb10x_gpio_probe(struct platform_device * pdev)108 static int tb10x_gpio_probe(struct platform_device *pdev)
109 {
110 struct tb10x_gpio *tb10x_gpio;
111 struct device *dev = &pdev->dev;
112 struct device_node *np = dev->of_node;
113 int ret = -EBUSY;
114 u32 ngpio;
115
116 if (!np)
117 return -EINVAL;
118
119 if (of_property_read_u32(np, "abilis,ngpio", &ngpio))
120 return -EINVAL;
121
122 tb10x_gpio = devm_kzalloc(dev, sizeof(*tb10x_gpio), GFP_KERNEL);
123 if (tb10x_gpio == NULL)
124 return -ENOMEM;
125
126 tb10x_gpio->base = devm_platform_ioremap_resource(pdev, 0);
127 if (IS_ERR(tb10x_gpio->base))
128 return PTR_ERR(tb10x_gpio->base);
129
130 tb10x_gpio->gc.label =
131 devm_kasprintf(dev, GFP_KERNEL, "%pOF", pdev->dev.of_node);
132 if (!tb10x_gpio->gc.label)
133 return -ENOMEM;
134
135 /*
136 * Initialize generic GPIO with one single register for reading and setting
137 * the lines, no special set or clear registers and a data direction register
138 * wher 1 means "output".
139 */
140 ret = bgpio_init(&tb10x_gpio->gc, dev, 4,
141 tb10x_gpio->base + OFFSET_TO_REG_DATA,
142 NULL,
143 NULL,
144 tb10x_gpio->base + OFFSET_TO_REG_DDR,
145 NULL,
146 0);
147 if (ret) {
148 dev_err(dev, "unable to init generic GPIO\n");
149 return ret;
150 }
151 tb10x_gpio->gc.base = -1;
152 tb10x_gpio->gc.parent = dev;
153 tb10x_gpio->gc.owner = THIS_MODULE;
154 /*
155 * ngpio is set by bgpio_init() but we override it, this .request()
156 * callback also overrides the one set up by generic GPIO.
157 */
158 tb10x_gpio->gc.ngpio = ngpio;
159 tb10x_gpio->gc.request = gpiochip_generic_request;
160 tb10x_gpio->gc.free = gpiochip_generic_free;
161
162 ret = devm_gpiochip_add_data(dev, &tb10x_gpio->gc, tb10x_gpio);
163 if (ret < 0) {
164 dev_err(dev, "Could not add gpiochip.\n");
165 return ret;
166 }
167
168 platform_set_drvdata(pdev, tb10x_gpio);
169
170 if (of_find_property(np, "interrupt-controller", NULL)) {
171 struct irq_chip_generic *gc;
172
173 ret = platform_get_irq(pdev, 0);
174 if (ret < 0)
175 return ret;
176
177 tb10x_gpio->gc.to_irq = tb10x_gpio_to_irq;
178 tb10x_gpio->irq = ret;
179
180 ret = devm_request_irq(dev, ret, tb10x_gpio_irq_cascade,
181 IRQF_TRIGGER_NONE | IRQF_SHARED,
182 dev_name(dev), tb10x_gpio);
183 if (ret != 0)
184 return ret;
185
186 tb10x_gpio->domain = irq_domain_add_linear(np,
187 tb10x_gpio->gc.ngpio,
188 &irq_generic_chip_ops, NULL);
189 if (!tb10x_gpio->domain) {
190 return -ENOMEM;
191 }
192
193 ret = irq_alloc_domain_generic_chips(tb10x_gpio->domain,
194 tb10x_gpio->gc.ngpio, 1, tb10x_gpio->gc.label,
195 handle_edge_irq, IRQ_NOREQUEST, IRQ_NOPROBE,
196 IRQ_GC_INIT_MASK_CACHE);
197 if (ret)
198 goto err_remove_domain;
199
200 gc = tb10x_gpio->domain->gc->gc[0];
201 gc->reg_base = tb10x_gpio->base;
202 gc->chip_types[0].type = IRQ_TYPE_EDGE_BOTH;
203 gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
204 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
205 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
206 gc->chip_types[0].chip.irq_set_type = tb10x_gpio_irq_set_type;
207 gc->chip_types[0].regs.ack = OFFSET_TO_REG_CHANGE;
208 gc->chip_types[0].regs.mask = OFFSET_TO_REG_INT_EN;
209 }
210
211 return 0;
212
213 err_remove_domain:
214 irq_domain_remove(tb10x_gpio->domain);
215 return ret;
216 }
217
tb10x_gpio_remove(struct platform_device * pdev)218 static int tb10x_gpio_remove(struct platform_device *pdev)
219 {
220 struct tb10x_gpio *tb10x_gpio = platform_get_drvdata(pdev);
221
222 if (tb10x_gpio->gc.to_irq) {
223 irq_remove_generic_chip(tb10x_gpio->domain->gc->gc[0],
224 BIT(tb10x_gpio->gc.ngpio) - 1, 0, 0);
225 kfree(tb10x_gpio->domain->gc);
226 irq_domain_remove(tb10x_gpio->domain);
227 }
228
229 return 0;
230 }
231
232 static const struct of_device_id tb10x_gpio_dt_ids[] = {
233 { .compatible = "abilis,tb10x-gpio" },
234 { }
235 };
236 MODULE_DEVICE_TABLE(of, tb10x_gpio_dt_ids);
237
238 static struct platform_driver tb10x_gpio_driver = {
239 .probe = tb10x_gpio_probe,
240 .remove = tb10x_gpio_remove,
241 .driver = {
242 .name = "tb10x-gpio",
243 .of_match_table = tb10x_gpio_dt_ids,
244 }
245 };
246
247 module_platform_driver(tb10x_gpio_driver);
248 MODULE_LICENSE("GPL");
249 MODULE_DESCRIPTION("tb10x gpio.");
250