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/mod_devicetable.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17
18 /* GPIO flavor */
19 #define GPIO_REG_DIR 0x00
20 #define GPIO_REG_OUT 0x01
21 #define GPIO_REG_IN 0x02
22 #define GPIO_REG_IE 0x03
23 #define GPIO_REG_IP 0x04
24
25 /* input-only flavor */
26 #define GPI_REG_IN 0x00
27
28 /* output-only flavor */
29 #define GPO_REG_OUT 0x00
30
31 enum sl28cpld_gpio_type {
32 SL28CPLD_GPIO = 1,
33 SL28CPLD_GPI,
34 SL28CPLD_GPO,
35 };
36
37 static const struct regmap_irq sl28cpld_gpio_irqs[] = {
38 REGMAP_IRQ_REG_LINE(0, 8),
39 REGMAP_IRQ_REG_LINE(1, 8),
40 REGMAP_IRQ_REG_LINE(2, 8),
41 REGMAP_IRQ_REG_LINE(3, 8),
42 REGMAP_IRQ_REG_LINE(4, 8),
43 REGMAP_IRQ_REG_LINE(5, 8),
44 REGMAP_IRQ_REG_LINE(6, 8),
45 REGMAP_IRQ_REG_LINE(7, 8),
46 };
47
sl28cpld_gpio_irq_init(struct platform_device * pdev,unsigned int base,struct gpio_regmap_config * config)48 static int sl28cpld_gpio_irq_init(struct platform_device *pdev,
49 unsigned int base,
50 struct gpio_regmap_config *config)
51 {
52 struct regmap_irq_chip_data *irq_data;
53 struct regmap_irq_chip *irq_chip;
54 struct device *dev = &pdev->dev;
55 int irq, ret;
56
57 if (!device_property_read_bool(dev, "interrupt-controller"))
58 return 0;
59
60 irq = platform_get_irq(pdev, 0);
61 if (irq < 0)
62 return irq;
63
64 irq_chip = devm_kzalloc(dev, sizeof(*irq_chip), GFP_KERNEL);
65 if (!irq_chip)
66 return -ENOMEM;
67
68 irq_chip->name = "sl28cpld-gpio-irq";
69 irq_chip->irqs = sl28cpld_gpio_irqs;
70 irq_chip->num_irqs = ARRAY_SIZE(sl28cpld_gpio_irqs);
71 irq_chip->num_regs = 1;
72 irq_chip->status_base = base + GPIO_REG_IP;
73 irq_chip->unmask_base = base + GPIO_REG_IE;
74 irq_chip->ack_base = base + GPIO_REG_IP;
75
76 ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
77 config->regmap, irq,
78 IRQF_SHARED | IRQF_ONESHOT,
79 0, irq_chip, &irq_data);
80 if (ret)
81 return ret;
82
83 config->irq_domain = regmap_irq_get_domain(irq_data);
84
85 return 0;
86 }
87
sl28cpld_gpio_probe(struct platform_device * pdev)88 static int sl28cpld_gpio_probe(struct platform_device *pdev)
89 {
90 struct gpio_regmap_config config = {0};
91 enum sl28cpld_gpio_type type;
92 struct regmap *regmap;
93 u32 base;
94 int ret;
95
96 if (!pdev->dev.parent)
97 return -ENODEV;
98
99 type = (uintptr_t)device_get_match_data(&pdev->dev);
100 if (!type)
101 return -ENODEV;
102
103 ret = device_property_read_u32(&pdev->dev, "reg", &base);
104 if (ret)
105 return -EINVAL;
106
107 regmap = dev_get_regmap(pdev->dev.parent, NULL);
108 if (!regmap)
109 return -ENODEV;
110
111 config.regmap = regmap;
112 config.parent = &pdev->dev;
113 config.ngpio = 8;
114
115 switch (type) {
116 case SL28CPLD_GPIO:
117 config.reg_dat_base = base + GPIO_REG_IN;
118 config.reg_set_base = base + GPIO_REG_OUT;
119 /* reg_dir_out_base might be zero */
120 config.reg_dir_out_base = GPIO_REGMAP_ADDR(base + GPIO_REG_DIR);
121
122 /* This type supports interrupts */
123 ret = sl28cpld_gpio_irq_init(pdev, base, &config);
124 if (ret)
125 return ret;
126 break;
127 case SL28CPLD_GPO:
128 config.reg_set_base = base + GPO_REG_OUT;
129 break;
130 case SL28CPLD_GPI:
131 config.reg_dat_base = base + GPI_REG_IN;
132 break;
133 default:
134 dev_err(&pdev->dev, "unknown type %d\n", type);
135 return -ENODEV;
136 }
137
138 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
139 }
140
141 static const struct of_device_id sl28cpld_gpio_of_match[] = {
142 { .compatible = "kontron,sl28cpld-gpio", .data = (void *)SL28CPLD_GPIO },
143 { .compatible = "kontron,sl28cpld-gpi", .data = (void *)SL28CPLD_GPI },
144 { .compatible = "kontron,sl28cpld-gpo", .data = (void *)SL28CPLD_GPO },
145 {}
146 };
147 MODULE_DEVICE_TABLE(of, sl28cpld_gpio_of_match);
148
149 static struct platform_driver sl28cpld_gpio_driver = {
150 .probe = sl28cpld_gpio_probe,
151 .driver = {
152 .name = "sl28cpld-gpio",
153 .of_match_table = sl28cpld_gpio_of_match,
154 },
155 };
156 module_platform_driver(sl28cpld_gpio_driver);
157
158 MODULE_DESCRIPTION("sl28cpld GPIO Driver");
159 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
160 MODULE_LICENSE("GPL");
161