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c16485ad PK |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * Copyright (C) 2019 Bootlin | |
4 | * Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com> | |
5 | */ | |
6 | ||
7 | #include <linux/err.h> | |
8 | #include <linux/gpio/driver.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/of.h> | |
c16485ad PK |
11 | #include <linux/of_address.h> |
12 | #include <linux/platform_device.h> | |
13 | #include <linux/regmap.h> | |
14 | #include <linux/mfd/syscon.h> | |
15 | ||
16 | #define LOGICVC_CTRL_REG 0x40 | |
17 | #define LOGICVC_CTRL_GPIO_SHIFT 11 | |
18 | #define LOGICVC_CTRL_GPIO_BITS 5 | |
19 | ||
20 | #define LOGICVC_POWER_CTRL_REG 0x78 | |
21 | #define LOGICVC_POWER_CTRL_GPIO_SHIFT 0 | |
22 | #define LOGICVC_POWER_CTRL_GPIO_BITS 4 | |
23 | ||
24 | struct logicvc_gpio { | |
25 | struct gpio_chip chip; | |
26 | struct regmap *regmap; | |
27 | }; | |
28 | ||
29 | static void logicvc_gpio_offset(struct logicvc_gpio *logicvc, unsigned offset, | |
30 | unsigned int *reg, unsigned int *bit) | |
31 | { | |
32 | if (offset >= LOGICVC_CTRL_GPIO_BITS) { | |
33 | *reg = LOGICVC_POWER_CTRL_REG; | |
34 | ||
35 | /* To the (virtual) power ctrl offset. */ | |
36 | offset -= LOGICVC_CTRL_GPIO_BITS; | |
37 | /* To the actual bit offset in reg. */ | |
38 | offset += LOGICVC_POWER_CTRL_GPIO_SHIFT; | |
39 | } else { | |
40 | *reg = LOGICVC_CTRL_REG; | |
41 | ||
42 | /* To the actual bit offset in reg. */ | |
43 | offset += LOGICVC_CTRL_GPIO_SHIFT; | |
44 | } | |
45 | ||
46 | *bit = BIT(offset); | |
47 | } | |
48 | ||
49 | static int logicvc_gpio_get(struct gpio_chip *chip, unsigned offset) | |
50 | { | |
51 | struct logicvc_gpio *logicvc = gpiochip_get_data(chip); | |
52 | unsigned int reg, bit, value; | |
53 | int ret; | |
54 | ||
55 | logicvc_gpio_offset(logicvc, offset, ®, &bit); | |
56 | ||
57 | ret = regmap_read(logicvc->regmap, reg, &value); | |
58 | if (ret) | |
59 | return ret; | |
60 | ||
61 | return !!(value & bit); | |
62 | } | |
63 | ||
64 | static void logicvc_gpio_set(struct gpio_chip *chip, unsigned offset, int value) | |
65 | { | |
66 | struct logicvc_gpio *logicvc = gpiochip_get_data(chip); | |
67 | unsigned int reg, bit; | |
68 | ||
69 | logicvc_gpio_offset(logicvc, offset, ®, &bit); | |
70 | ||
71 | regmap_update_bits(logicvc->regmap, reg, bit, value ? bit : 0); | |
72 | } | |
73 | ||
74 | static int logicvc_gpio_direction_output(struct gpio_chip *chip, | |
75 | unsigned offset, int value) | |
76 | { | |
77 | /* Pins are always configured as output, so just set the value. */ | |
78 | logicvc_gpio_set(chip, offset, value); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static struct regmap_config logicvc_gpio_regmap_config = { | |
84 | .reg_bits = 32, | |
85 | .val_bits = 32, | |
86 | .reg_stride = 4, | |
87 | .name = "logicvc-gpio", | |
88 | }; | |
89 | ||
90 | static int logicvc_gpio_probe(struct platform_device *pdev) | |
91 | { | |
92 | struct device *dev = &pdev->dev; | |
93 | struct device_node *of_node = dev->of_node; | |
94 | struct logicvc_gpio *logicvc; | |
95 | int ret; | |
96 | ||
97 | logicvc = devm_kzalloc(dev, sizeof(*logicvc), GFP_KERNEL); | |
98 | if (!logicvc) | |
99 | return -ENOMEM; | |
100 | ||
101 | /* Try to get regmap from parent first. */ | |
102 | logicvc->regmap = syscon_node_to_regmap(of_node->parent); | |
103 | ||
104 | /* Grab our own regmap if that fails. */ | |
105 | if (IS_ERR(logicvc->regmap)) { | |
106 | struct resource res; | |
107 | void __iomem *base; | |
108 | ||
109 | ret = of_address_to_resource(of_node, 0, &res); | |
110 | if (ret) { | |
111 | dev_err(dev, "Failed to get resource from address\n"); | |
112 | return ret; | |
113 | } | |
114 | ||
115 | base = devm_ioremap_resource(dev, &res); | |
c35fb576 | 116 | if (IS_ERR(base)) |
c16485ad | 117 | return PTR_ERR(base); |
c16485ad PK |
118 | |
119 | logicvc_gpio_regmap_config.max_register = resource_size(&res) - | |
120 | logicvc_gpio_regmap_config.reg_stride; | |
121 | ||
122 | logicvc->regmap = | |
123 | devm_regmap_init_mmio(dev, base, | |
124 | &logicvc_gpio_regmap_config); | |
125 | if (IS_ERR(logicvc->regmap)) { | |
126 | dev_err(dev, "Failed to create regmap for I/O\n"); | |
127 | return PTR_ERR(logicvc->regmap); | |
128 | } | |
129 | } | |
130 | ||
131 | logicvc->chip.parent = dev; | |
132 | logicvc->chip.owner = THIS_MODULE; | |
133 | logicvc->chip.label = dev_name(dev); | |
134 | logicvc->chip.base = -1; | |
135 | logicvc->chip.ngpio = LOGICVC_CTRL_GPIO_BITS + | |
136 | LOGICVC_POWER_CTRL_GPIO_BITS; | |
137 | logicvc->chip.get = logicvc_gpio_get; | |
138 | logicvc->chip.set = logicvc_gpio_set; | |
139 | logicvc->chip.direction_output = logicvc_gpio_direction_output; | |
140 | ||
c16485ad PK |
141 | return devm_gpiochip_add_data(dev, &logicvc->chip, logicvc); |
142 | } | |
143 | ||
144 | static const struct of_device_id logicivc_gpio_of_table[] = { | |
145 | { | |
146 | .compatible = "xylon,logicvc-3.02.a-gpio", | |
147 | }, | |
148 | { } | |
149 | }; | |
150 | ||
151 | MODULE_DEVICE_TABLE(of, logicivc_gpio_of_table); | |
152 | ||
153 | static struct platform_driver logicvc_gpio_driver = { | |
154 | .driver = { | |
155 | .name = "gpio-logicvc", | |
156 | .of_match_table = logicivc_gpio_of_table, | |
157 | }, | |
158 | .probe = logicvc_gpio_probe, | |
159 | }; | |
160 | ||
161 | module_platform_driver(logicvc_gpio_driver); | |
162 | ||
163 | MODULE_AUTHOR("Paul Kocialkowski <paul.kocialkowski@bootlin.com>"); | |
164 | MODULE_DESCRIPTION("Xylon LogiCVC GPIO driver"); | |
165 | MODULE_LICENSE("GPL"); |