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8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/io.h>
11#include <linux/err.h>
12#include <linux/mcb.h>
13#include <linux/bitops.h>
14#include <linux/gpio/driver.h>
15
16#define MEN_Z127_CTRL 0x00
17#define MEN_Z127_PSR 0x04
18#define MEN_Z127_IRQR 0x08
19#define MEN_Z127_GPIODR 0x0c
20#define MEN_Z127_IER1 0x10
21#define MEN_Z127_IER2 0x14
22#define MEN_Z127_DBER 0x18
23#define MEN_Z127_ODER 0x1C
24#define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80)
25
26#define MEN_Z127_DB_MIN_US 50
27
28#define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US)
29#define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \
30 (db <= MEN_Z127_DB_MAX_US))
31
32struct men_z127_gpio {
33 struct gpio_chip gc;
34 void __iomem *reg_base;
35 struct resource *mem;
36};
37
38static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio,
39 unsigned debounce)
40{
41 struct men_z127_gpio *priv = gpiochip_get_data(gc);
42 struct device *dev = gc->parent;
43 unsigned int rnd;
44 u32 db_en, db_cnt;
45
46 if (!MEN_Z127_DB_IN_RANGE(debounce)) {
47 dev_err(dev, "debounce value %u out of range", debounce);
48 return -EINVAL;
49 }
50
51 if (debounce > 0) {
52
53 rnd = fls(debounce) - 1;
54
55 if (rnd && (debounce & BIT(rnd - 1)))
56 debounce = roundup(debounce, MEN_Z127_DB_MIN_US);
57 else
58 debounce = rounddown(debounce, MEN_Z127_DB_MIN_US);
59
60 if (debounce > MEN_Z127_DB_MAX_US)
61 debounce = MEN_Z127_DB_MAX_US;
62
63
64 debounce /= 50;
65 }
66
67 spin_lock(&gc->bgpio_lock);
68
69 db_en = readl(priv->reg_base + MEN_Z127_DBER);
70
71 if (debounce == 0) {
72 db_en &= ~BIT(gpio);
73 db_cnt = 0;
74 } else {
75 db_en |= BIT(gpio);
76 db_cnt = debounce;
77 }
78
79 writel(db_en, priv->reg_base + MEN_Z127_DBER);
80 writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio));
81
82 spin_unlock(&gc->bgpio_lock);
83
84 return 0;
85}
86
87static int men_z127_set_single_ended(struct gpio_chip *gc,
88 unsigned offset,
89 enum pin_config_param param)
90{
91 struct men_z127_gpio *priv = gpiochip_get_data(gc);
92 u32 od_en;
93
94 spin_lock(&gc->bgpio_lock);
95 od_en = readl(priv->reg_base + MEN_Z127_ODER);
96
97 if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)
98 od_en |= BIT(offset);
99 else
100
101 od_en &= ~BIT(offset);
102
103 writel(od_en, priv->reg_base + MEN_Z127_ODER);
104 spin_unlock(&gc->bgpio_lock);
105
106 return 0;
107}
108
109static int men_z127_set_config(struct gpio_chip *gc, unsigned offset,
110 unsigned long config)
111{
112 enum pin_config_param param = pinconf_to_config_param(config);
113
114 switch (param) {
115 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
116 case PIN_CONFIG_DRIVE_PUSH_PULL:
117 return men_z127_set_single_ended(gc, offset, param);
118
119 case PIN_CONFIG_INPUT_DEBOUNCE:
120 return men_z127_debounce(gc, offset,
121 pinconf_to_config_argument(config));
122
123 default:
124 break;
125 }
126
127 return -ENOTSUPP;
128}
129
130static int men_z127_probe(struct mcb_device *mdev,
131 const struct mcb_device_id *id)
132{
133 struct men_z127_gpio *men_z127_gpio;
134 struct device *dev = &mdev->dev;
135 int ret;
136
137 men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio),
138 GFP_KERNEL);
139 if (!men_z127_gpio)
140 return -ENOMEM;
141
142 men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev));
143 if (IS_ERR(men_z127_gpio->mem)) {
144 dev_err(dev, "failed to request device memory");
145 return PTR_ERR(men_z127_gpio->mem);
146 }
147
148 men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start,
149 resource_size(men_z127_gpio->mem));
150 if (men_z127_gpio->reg_base == NULL) {
151 ret = -ENXIO;
152 goto err_release;
153 }
154
155 mcb_set_drvdata(mdev, men_z127_gpio);
156
157 ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4,
158 men_z127_gpio->reg_base + MEN_Z127_PSR,
159 men_z127_gpio->reg_base + MEN_Z127_CTRL,
160 NULL,
161 men_z127_gpio->reg_base + MEN_Z127_GPIODR,
162 NULL, 0);
163 if (ret)
164 goto err_unmap;
165
166 men_z127_gpio->gc.set_config = men_z127_set_config;
167
168 ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio);
169 if (ret) {
170 dev_err(dev, "failed to register MEN 16Z127 GPIO controller");
171 goto err_unmap;
172 }
173
174 dev_info(dev, "MEN 16Z127 GPIO driver registered");
175
176 return 0;
177
178err_unmap:
179 iounmap(men_z127_gpio->reg_base);
180err_release:
181 mcb_release_mem(men_z127_gpio->mem);
182 return ret;
183}
184
185static void men_z127_remove(struct mcb_device *mdev)
186{
187 struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev);
188
189 gpiochip_remove(&men_z127_gpio->gc);
190 iounmap(men_z127_gpio->reg_base);
191 mcb_release_mem(men_z127_gpio->mem);
192}
193
194static const struct mcb_device_id men_z127_ids[] = {
195 { .device = 0x7f },
196 { }
197};
198MODULE_DEVICE_TABLE(mcb, men_z127_ids);
199
200static struct mcb_driver men_z127_driver = {
201 .driver = {
202 .name = "z127-gpio",
203 },
204 .probe = men_z127_probe,
205 .remove = men_z127_remove,
206 .id_table = men_z127_ids,
207};
208module_mcb_driver(men_z127_driver);
209
210MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
211MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");
212MODULE_LICENSE("GPL v2");
213MODULE_ALIAS("mcb:16z127");
214MODULE_IMPORT_NS(MCB);
215
