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13#include <linux/bitops.h>
14#include <linux/err.h>
15#include <linux/gpio.h>
16#include <linux/i2c.h>
17#include <linux/mfd/lp3943.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/slab.h>
21
22enum lp3943_gpios {
23 LP3943_GPIO1,
24 LP3943_GPIO2,
25 LP3943_GPIO3,
26 LP3943_GPIO4,
27 LP3943_GPIO5,
28 LP3943_GPIO6,
29 LP3943_GPIO7,
30 LP3943_GPIO8,
31 LP3943_GPIO9,
32 LP3943_GPIO10,
33 LP3943_GPIO11,
34 LP3943_GPIO12,
35 LP3943_GPIO13,
36 LP3943_GPIO14,
37 LP3943_GPIO15,
38 LP3943_GPIO16,
39 LP3943_MAX_GPIO,
40};
41
42struct lp3943_gpio {
43 struct gpio_chip chip;
44 struct lp3943 *lp3943;
45 u16 input_mask;
46};
47
48static inline struct lp3943_gpio *to_lp3943_gpio(struct gpio_chip *_chip)
49{
50 return container_of(_chip, struct lp3943_gpio, chip);
51}
52
53static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset)
54{
55 struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
56 struct lp3943 *lp3943 = lp3943_gpio->lp3943;
57
58
59 if (test_and_set_bit(offset, &lp3943->pin_used))
60 return -EBUSY;
61
62 return 0;
63}
64
65static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset)
66{
67 struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
68 struct lp3943 *lp3943 = lp3943_gpio->lp3943;
69
70 clear_bit(offset, &lp3943->pin_used);
71}
72
73static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset,
74 u8 val)
75{
76 struct lp3943 *lp3943 = lp3943_gpio->lp3943;
77 const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
78
79 return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask,
80 val << mux[offset].shift);
81}
82
83static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
84{
85 struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
86
87 lp3943_gpio->input_mask |= BIT(offset);
88
89 return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN);
90}
91
92static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio,
93 struct gpio_chip *chip, unsigned offset)
94{
95 u8 addr, read;
96 int err;
97
98 switch (offset) {
99 case LP3943_GPIO1 ... LP3943_GPIO8:
100 addr = LP3943_REG_GPIO_A;
101 break;
102 case LP3943_GPIO9 ... LP3943_GPIO16:
103 addr = LP3943_REG_GPIO_B;
104 offset = offset - 8;
105 break;
106 default:
107 return -EINVAL;
108 }
109
110 err = lp3943_read_byte(lp3943_gpio->lp3943, addr, &read);
111 if (err)
112 return err;
113
114 return !!(read & BIT(offset));
115}
116
117static int lp3943_get_gpio_out_status(struct lp3943_gpio *lp3943_gpio,
118 struct gpio_chip *chip, unsigned offset)
119{
120 struct lp3943 *lp3943 = lp3943_gpio->lp3943;
121 const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
122 u8 read;
123 int err;
124
125 err = lp3943_read_byte(lp3943, mux[offset].reg, &read);
126 if (err)
127 return err;
128
129 read = (read & mux[offset].mask) >> mux[offset].shift;
130
131 if (read == LP3943_GPIO_OUT_HIGH)
132 return 1;
133 else if (read == LP3943_GPIO_OUT_LOW)
134 return 0;
135 else
136 return -EINVAL;
137}
138
139static int lp3943_gpio_get(struct gpio_chip *chip, unsigned offset)
140{
141 struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
142
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150
151
152 if (lp3943_gpio->input_mask & BIT(offset))
153 return lp3943_get_gpio_in_status(lp3943_gpio, chip, offset);
154 else
155 return lp3943_get_gpio_out_status(lp3943_gpio, chip, offset);
156}
157
158static void lp3943_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
159{
160 struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
161 u8 data;
162
163 if (value)
164 data = LP3943_GPIO_OUT_HIGH;
165 else
166 data = LP3943_GPIO_OUT_LOW;
167
168 lp3943_gpio_set_mode(lp3943_gpio, offset, data);
169}
170
171static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
172 int value)
173{
174 struct lp3943_gpio *lp3943_gpio = to_lp3943_gpio(chip);
175
176 lp3943_gpio_set(chip, offset, value);
177 lp3943_gpio->input_mask &= ~BIT(offset);
178
179 return 0;
180}
181
182static const struct gpio_chip lp3943_gpio_chip = {
183 .label = "lp3943",
184 .owner = THIS_MODULE,
185 .request = lp3943_gpio_request,
186 .free = lp3943_gpio_free,
187 .direction_input = lp3943_gpio_direction_input,
188 .get = lp3943_gpio_get,
189 .direction_output = lp3943_gpio_direction_output,
190 .set = lp3943_gpio_set,
191 .base = -1,
192 .ngpio = LP3943_MAX_GPIO,
193 .can_sleep = 1,
194};
195
196static int lp3943_gpio_probe(struct platform_device *pdev)
197{
198 struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
199 struct lp3943_gpio *lp3943_gpio;
200
201 lp3943_gpio = devm_kzalloc(&pdev->dev, sizeof(*lp3943_gpio),
202 GFP_KERNEL);
203 if (!lp3943_gpio)
204 return -ENOMEM;
205
206 lp3943_gpio->lp3943 = lp3943;
207 lp3943_gpio->chip = lp3943_gpio_chip;
208 lp3943_gpio->chip.dev = &pdev->dev;
209
210 platform_set_drvdata(pdev, lp3943_gpio);
211
212 return gpiochip_add(&lp3943_gpio->chip);
213}
214
215static int lp3943_gpio_remove(struct platform_device *pdev)
216{
217 struct lp3943_gpio *lp3943_gpio = platform_get_drvdata(pdev);
218
219 gpiochip_remove(&lp3943_gpio->chip);
220 return 0;
221}
222
223static const struct of_device_id lp3943_gpio_of_match[] = {
224 { .compatible = "ti,lp3943-gpio", },
225 { }
226};
227MODULE_DEVICE_TABLE(of, lp3943_gpio_of_match);
228
229static struct platform_driver lp3943_gpio_driver = {
230 .probe = lp3943_gpio_probe,
231 .remove = lp3943_gpio_remove,
232 .driver = {
233 .name = "lp3943-gpio",
234 .of_match_table = lp3943_gpio_of_match,
235 },
236};
237module_platform_driver(lp3943_gpio_driver);
238
239MODULE_DESCRIPTION("LP3943 GPIO driver");
240MODULE_ALIAS("platform:lp3943-gpio");
241MODULE_AUTHOR("Milo Kim");
242MODULE_LICENSE("GPL");
243
