1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * sl28cpld GPIO driver
4 *
5 * Copyright 2020 Michael Walle <michael@walle.cc>
6 */
7
8 #include <linux/device.h>
9 #include <linux/gpio/driver.h>
10 #include <linux/gpio/regmap.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/regmap.h>
16
17 /* GPIO flavor */
18 #define GPIO_REG_DIR 0x00
19 #define GPIO_REG_OUT 0x01
20 #define GPIO_REG_IN 0x02
21 #define GPIO_REG_IE 0x03
22 #define GPIO_REG_IP 0x04
23
24 /* input-only flavor */
25 #define GPI_REG_IN 0x00
26
27 /* output-only flavor */
28 #define GPO_REG_OUT 0x00
29
30 enum sl28cpld_gpio_type {
31 SL28CPLD_GPIO = 1,
32 SL28CPLD_GPI,
33 SL28CPLD_GPO,
34 };
35
36 static const struct regmap_irq sl28cpld_gpio_irqs[] = {
37 REGMAP_IRQ_REG_LINE(0, 8),
38 REGMAP_IRQ_REG_LINE(1, 8),
39 REGMAP_IRQ_REG_LINE(2, 8),
40 REGMAP_IRQ_REG_LINE(3, 8),
41 REGMAP_IRQ_REG_LINE(4, 8),
42 REGMAP_IRQ_REG_LINE(5, 8),
43 REGMAP_IRQ_REG_LINE(6, 8),
44 REGMAP_IRQ_REG_LINE(7, 8),
45 };
46
sl28cpld_gpio_irq_init(struct platform_device * pdev,unsigned int base,struct gpio_regmap_config * config)47 static int sl28cpld_gpio_irq_init(struct platform_device *pdev,
48 unsigned int base,
49 struct gpio_regmap_config *config)
50 {
51 struct regmap_irq_chip_data *irq_data;
52 struct regmap_irq_chip *irq_chip;
53 struct device *dev = &pdev->dev;
54 int irq, ret;
55
56 if (!device_property_read_bool(dev, "interrupt-controller"))
57 return 0;
58
59 irq = platform_get_irq(pdev, 0);
60 if (irq < 0)
61 return irq;
62
63 irq_chip = devm_kzalloc(dev, sizeof(*irq_chip), GFP_KERNEL);
64 if (!irq_chip)
65 return -ENOMEM;
66
67 irq_chip->name = "sl28cpld-gpio-irq";
68 irq_chip->irqs = sl28cpld_gpio_irqs;
69 irq_chip->num_irqs = ARRAY_SIZE(sl28cpld_gpio_irqs);
70 irq_chip->num_regs = 1;
71 irq_chip->status_base = base + GPIO_REG_IP;
72 irq_chip->unmask_base = base + GPIO_REG_IE;
73 irq_chip->ack_base = base + GPIO_REG_IP;
74
75 ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
76 config->regmap, irq,
77 IRQF_SHARED | IRQF_ONESHOT,
78 0, irq_chip, &irq_data);
79 if (ret)
80 return ret;
81
82 config->irq_domain = regmap_irq_get_domain(irq_data);
83
84 return 0;
85 }
86
sl28cpld_gpio_probe(struct platform_device * pdev)87 static int sl28cpld_gpio_probe(struct platform_device *pdev)
88 {
89 struct gpio_regmap_config config = {0};
90 enum sl28cpld_gpio_type type;
91 struct regmap *regmap;
92 u32 base;
93 int ret;
94
95 if (!pdev->dev.parent)
96 return -ENODEV;
97
98 type = (uintptr_t)device_get_match_data(&pdev->dev);
99 if (!type)
100 return -ENODEV;
101
102 ret = device_property_read_u32(&pdev->dev, "reg", &base);
103 if (ret)
104 return -EINVAL;
105
106 regmap = dev_get_regmap(pdev->dev.parent, NULL);
107 if (!regmap)
108 return -ENODEV;
109
110 config.regmap = regmap;
111 config.parent = &pdev->dev;
112 config.ngpio = 8;
113
114 switch (type) {
115 case SL28CPLD_GPIO:
116 config.reg_dat_base = base + GPIO_REG_IN;
117 config.reg_set_base = base + GPIO_REG_OUT;
118 /* reg_dir_out_base might be zero */
119 config.reg_dir_out_base = GPIO_REGMAP_ADDR(base + GPIO_REG_DIR);
120
121 /* This type supports interrupts */
122 ret = sl28cpld_gpio_irq_init(pdev, base, &config);
123 if (ret)
124 return ret;
125 break;
126 case SL28CPLD_GPO:
127 config.reg_set_base = base + GPO_REG_OUT;
128 break;
129 case SL28CPLD_GPI:
130 config.reg_dat_base = base + GPI_REG_IN;
131 break;
132 default:
133 dev_err(&pdev->dev, "unknown type %d\n", type);
134 return -ENODEV;
135 }
136
137 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
138 }
139
140 static const struct of_device_id sl28cpld_gpio_of_match[] = {
141 { .compatible = "kontron,sl28cpld-gpio", .data = (void *)SL28CPLD_GPIO },
142 { .compatible = "kontron,sl28cpld-gpi", .data = (void *)SL28CPLD_GPI },
143 { .compatible = "kontron,sl28cpld-gpo", .data = (void *)SL28CPLD_GPO },
144 {}
145 };
146 MODULE_DEVICE_TABLE(of, sl28cpld_gpio_of_match);
147
148 static struct platform_driver sl28cpld_gpio_driver = {
149 .probe = sl28cpld_gpio_probe,
150 .driver = {
151 .name = "sl28cpld-gpio",
152 .of_match_table = sl28cpld_gpio_of_match,
153 },
154 };
155 module_platform_driver(sl28cpld_gpio_driver);
156
157 MODULE_DESCRIPTION("sl28cpld GPIO Driver");
158 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
159 MODULE_LICENSE("GPL");
160