Commit | Line | Data |
---|---|---|
fb0b35d3 AS |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * SAMA5D2 PIOBU GPIO controller | |
4 | * | |
5 | * Copyright (C) 2018 Microchip Technology Inc. and its subsidiaries | |
6 | * | |
7 | * Author: Andrei Stefanescu <andrei.stefanescu@microchip.com> | |
8 | * | |
9 | */ | |
10 | #include <linux/bits.h> | |
11 | #include <linux/gpio/driver.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/mfd/syscon.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/regmap.h> | |
19 | ||
20 | #define PIOBU_NUM 8 | |
21 | #define PIOBU_REG_SIZE 4 | |
22 | ||
23 | /* | |
24 | * backup mode protection register for tamper detection | |
25 | * normal mode protection register for tamper detection | |
26 | * wakeup signal generation | |
27 | */ | |
28 | #define PIOBU_BMPR 0x7C | |
29 | #define PIOBU_NMPR 0x80 | |
30 | #define PIOBU_WKPR 0x90 | |
31 | ||
32 | #define PIOBU_BASE 0x18 /* PIOBU offset from SECUMOD base register address. */ | |
33 | ||
34 | #define PIOBU_DET_OFFSET 16 | |
35 | ||
36 | /* In the datasheet this bit is called OUTPUT */ | |
37 | #define PIOBU_DIRECTION BIT(8) | |
38 | #define PIOBU_OUT BIT(8) | |
39 | #define PIOBU_IN 0 | |
40 | ||
41 | #define PIOBU_SOD BIT(9) | |
42 | #define PIOBU_PDS BIT(10) | |
43 | ||
44 | #define PIOBU_HIGH BIT(9) | |
45 | #define PIOBU_LOW 0 | |
46 | ||
47 | struct sama5d2_piobu { | |
48 | struct gpio_chip chip; | |
49 | struct regmap *regmap; | |
50 | }; | |
51 | ||
52 | /** | |
53 | * sama5d2_piobu_setup_pin() - prepares a pin for set_direction call | |
54 | * | |
55 | * Do not consider pin for tamper detection (normal and backup modes) | |
56 | * Do not consider pin as tamper wakeup interrupt source | |
57 | */ | |
58 | static int sama5d2_piobu_setup_pin(struct gpio_chip *chip, unsigned int pin) | |
59 | { | |
60 | int ret; | |
61 | struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu, | |
62 | chip); | |
63 | unsigned int mask = BIT(PIOBU_DET_OFFSET + pin); | |
64 | ||
65 | ret = regmap_update_bits(piobu->regmap, PIOBU_BMPR, mask, 0); | |
66 | if (ret) | |
67 | return ret; | |
68 | ||
69 | ret = regmap_update_bits(piobu->regmap, PIOBU_NMPR, mask, 0); | |
70 | if (ret) | |
71 | return ret; | |
72 | ||
73 | return regmap_update_bits(piobu->regmap, PIOBU_WKPR, mask, 0); | |
74 | } | |
75 | ||
76 | /** | |
77 | * sama5d2_piobu_write_value() - writes value & mask at the pin's PIOBU register | |
78 | */ | |
79 | static int sama5d2_piobu_write_value(struct gpio_chip *chip, unsigned int pin, | |
80 | unsigned int mask, unsigned int value) | |
81 | { | |
82 | int reg; | |
83 | struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu, | |
84 | chip); | |
85 | ||
86 | reg = PIOBU_BASE + pin * PIOBU_REG_SIZE; | |
87 | ||
88 | return regmap_update_bits(piobu->regmap, reg, mask, value); | |
89 | } | |
90 | ||
91 | /** | |
92 | * sama5d2_piobu_read_value() - read the value with masking from the pin's PIOBU | |
93 | * register | |
94 | */ | |
95 | static int sama5d2_piobu_read_value(struct gpio_chip *chip, unsigned int pin, | |
96 | unsigned int mask) | |
97 | { | |
98 | struct sama5d2_piobu *piobu = container_of(chip, struct sama5d2_piobu, | |
99 | chip); | |
100 | unsigned int val, reg; | |
101 | int ret; | |
102 | ||
103 | reg = PIOBU_BASE + pin * PIOBU_REG_SIZE; | |
104 | ret = regmap_read(piobu->regmap, reg, &val); | |
105 | if (ret < 0) | |
106 | return ret; | |
107 | ||
108 | return val & mask; | |
109 | } | |
110 | ||
111 | /** | |
112 | * sama5d2_piobu_set_direction() - mark pin as input or output | |
113 | */ | |
114 | static int sama5d2_piobu_set_direction(struct gpio_chip *chip, | |
115 | unsigned int direction, | |
116 | unsigned int pin) | |
117 | { | |
118 | return sama5d2_piobu_write_value(chip, pin, PIOBU_DIRECTION, direction); | |
119 | } | |
120 | ||
121 | /** | |
122 | * sama5d2_piobu_get_direction() - gpiochip get_direction | |
123 | */ | |
124 | static int sama5d2_piobu_get_direction(struct gpio_chip *chip, | |
125 | unsigned int pin) | |
126 | { | |
127 | int ret = sama5d2_piobu_read_value(chip, pin, PIOBU_DIRECTION); | |
128 | ||
129 | if (ret < 0) | |
130 | return ret; | |
131 | ||
132 | return (ret == PIOBU_IN) ? 1 : 0; | |
133 | } | |
134 | ||
135 | /** | |
136 | * sama5d2_piobu_direction_input() - gpiochip direction_input | |
137 | */ | |
138 | static int sama5d2_piobu_direction_input(struct gpio_chip *chip, | |
139 | unsigned int pin) | |
140 | { | |
141 | return sama5d2_piobu_set_direction(chip, PIOBU_IN, pin); | |
142 | } | |
143 | ||
144 | /** | |
145 | * sama5d2_piobu_direction_output() - gpiochip direction_output | |
146 | */ | |
147 | static int sama5d2_piobu_direction_output(struct gpio_chip *chip, | |
148 | unsigned int pin, int value) | |
149 | { | |
150 | return sama5d2_piobu_set_direction(chip, PIOBU_OUT, pin); | |
151 | } | |
152 | ||
153 | /** | |
154 | * sama5d2_piobu_get() - gpiochip get | |
155 | */ | |
156 | static int sama5d2_piobu_get(struct gpio_chip *chip, unsigned int pin) | |
157 | { | |
158 | /* if pin is input, read value from PDS else read from SOD */ | |
159 | int ret = sama5d2_piobu_get_direction(chip, pin); | |
160 | ||
161 | if (ret == 1) | |
162 | ret = sama5d2_piobu_read_value(chip, pin, PIOBU_PDS); | |
163 | else if (!ret) | |
164 | ret = sama5d2_piobu_read_value(chip, pin, PIOBU_SOD); | |
165 | ||
166 | if (ret < 0) | |
167 | return ret; | |
168 | ||
169 | return !!ret; | |
170 | } | |
171 | ||
172 | /** | |
173 | * sama5d2_piobu_set() - gpiochip set | |
174 | */ | |
175 | static void sama5d2_piobu_set(struct gpio_chip *chip, unsigned int pin, | |
176 | int value) | |
177 | { | |
178 | if (!value) | |
179 | value = PIOBU_LOW; | |
180 | else | |
181 | value = PIOBU_HIGH; | |
182 | ||
183 | sama5d2_piobu_write_value(chip, pin, PIOBU_SOD, value); | |
184 | } | |
185 | ||
186 | static int sama5d2_piobu_probe(struct platform_device *pdev) | |
187 | { | |
188 | struct sama5d2_piobu *piobu; | |
189 | int ret, i; | |
190 | ||
191 | piobu = devm_kzalloc(&pdev->dev, sizeof(*piobu), GFP_KERNEL); | |
192 | if (!piobu) | |
193 | return -ENOMEM; | |
194 | ||
195 | platform_set_drvdata(pdev, piobu); | |
196 | piobu->chip.label = pdev->name; | |
197 | piobu->chip.parent = &pdev->dev; | |
198 | piobu->chip.of_node = pdev->dev.of_node; | |
199 | piobu->chip.owner = THIS_MODULE, | |
200 | piobu->chip.get_direction = sama5d2_piobu_get_direction, | |
201 | piobu->chip.direction_input = sama5d2_piobu_direction_input, | |
202 | piobu->chip.direction_output = sama5d2_piobu_direction_output, | |
203 | piobu->chip.get = sama5d2_piobu_get, | |
204 | piobu->chip.set = sama5d2_piobu_set, | |
205 | piobu->chip.base = -1, | |
206 | piobu->chip.ngpio = PIOBU_NUM, | |
207 | piobu->chip.can_sleep = 0, | |
208 | ||
209 | piobu->regmap = syscon_node_to_regmap(pdev->dev.of_node); | |
210 | if (IS_ERR(piobu->regmap)) { | |
211 | dev_err(&pdev->dev, "Failed to get syscon regmap %ld\n", | |
212 | PTR_ERR(piobu->regmap)); | |
213 | return PTR_ERR(piobu->regmap); | |
214 | } | |
215 | ||
216 | ret = devm_gpiochip_add_data(&pdev->dev, &piobu->chip, piobu); | |
217 | if (ret) { | |
218 | dev_err(&pdev->dev, "Failed to add gpiochip %d\n", ret); | |
219 | return ret; | |
220 | } | |
221 | ||
222 | for (i = 0; i < PIOBU_NUM; ++i) { | |
223 | ret = sama5d2_piobu_setup_pin(&piobu->chip, i); | |
224 | if (ret) { | |
225 | dev_err(&pdev->dev, "Failed to setup pin: %d %d\n", | |
226 | i, ret); | |
227 | return ret; | |
228 | } | |
229 | } | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
234 | static const struct of_device_id sama5d2_piobu_ids[] = { | |
235 | { .compatible = "atmel,sama5d2-secumod" }, | |
236 | {}, | |
237 | }; | |
238 | MODULE_DEVICE_TABLE(of, sama5d2_piobu_ids); | |
239 | ||
240 | static struct platform_driver sama5d2_piobu_driver = { | |
241 | .driver = { | |
242 | .name = "sama5d2-piobu", | |
243 | .of_match_table = of_match_ptr(sama5d2_piobu_ids) | |
244 | }, | |
245 | .probe = sama5d2_piobu_probe, | |
246 | }; | |
247 | ||
248 | module_platform_driver(sama5d2_piobu_driver); | |
249 | ||
250 | MODULE_VERSION("1.0"); | |
251 | MODULE_LICENSE("GPL v2"); | |
252 | MODULE_DESCRIPTION("SAMA5D2 PIOBU controller driver"); | |
253 | MODULE_AUTHOR("Andrei Stefanescu <andrei.stefanescu@microchip.com>"); |