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11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/slab.h>
15#include <linux/w1-gpio.h>
16#include <linux/gpio.h>
17#include <linux/of_platform.h>
18#include <linux/of_gpio.h>
19#include <linux/err.h>
20#include <linux/of.h>
21#include <linux/delay.h>
22
23#include "../w1.h"
24#include "../w1_int.h"
25
26static u8 w1_gpio_set_pullup(void *data, int delay)
27{
28 struct w1_gpio_platform_data *pdata = data;
29
30 if (delay) {
31 pdata->pullup_duration = delay;
32 } else {
33 if (pdata->pullup_duration) {
34 gpio_direction_output(pdata->pin, 1);
35
36 msleep(pdata->pullup_duration);
37
38 gpio_direction_input(pdata->pin);
39 }
40 pdata->pullup_duration = 0;
41 }
42
43 return 0;
44}
45
46static void w1_gpio_write_bit_dir(void *data, u8 bit)
47{
48 struct w1_gpio_platform_data *pdata = data;
49
50 if (bit)
51 gpio_direction_input(pdata->pin);
52 else
53 gpio_direction_output(pdata->pin, 0);
54}
55
56static void w1_gpio_write_bit_val(void *data, u8 bit)
57{
58 struct w1_gpio_platform_data *pdata = data;
59
60 gpio_set_value(pdata->pin, bit);
61}
62
63static u8 w1_gpio_read_bit(void *data)
64{
65 struct w1_gpio_platform_data *pdata = data;
66
67 return gpio_get_value(pdata->pin) ? 1 : 0;
68}
69
70#if defined(CONFIG_OF)
71static const struct of_device_id w1_gpio_dt_ids[] = {
72 { .compatible = "w1-gpio" },
73 {}
74};
75MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
76#endif
77
78static int w1_gpio_probe_dt(struct platform_device *pdev)
79{
80 struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
81 struct device_node *np = pdev->dev.of_node;
82 int gpio;
83
84 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
85 if (!pdata)
86 return -ENOMEM;
87
88 if (of_get_property(np, "linux,open-drain", NULL))
89 pdata->is_open_drain = 1;
90
91 gpio = of_get_gpio(np, 0);
92 if (gpio < 0) {
93 if (gpio != -EPROBE_DEFER)
94 dev_err(&pdev->dev,
95 "Failed to parse gpio property for data pin (%d)\n",
96 gpio);
97
98 return gpio;
99 }
100 pdata->pin = gpio;
101
102 gpio = of_get_gpio(np, 1);
103 if (gpio == -EPROBE_DEFER)
104 return gpio;
105
106 pdata->ext_pullup_enable_pin = gpio;
107
108 pdev->dev.platform_data = pdata;
109
110 return 0;
111}
112
113static int w1_gpio_probe(struct platform_device *pdev)
114{
115 struct w1_bus_master *master;
116 struct w1_gpio_platform_data *pdata;
117 int err;
118
119 if (of_have_populated_dt()) {
120 err = w1_gpio_probe_dt(pdev);
121 if (err < 0)
122 return err;
123 }
124
125 pdata = dev_get_platdata(&pdev->dev);
126
127 if (!pdata) {
128 dev_err(&pdev->dev, "No configuration data\n");
129 return -ENXIO;
130 }
131
132 master = devm_kzalloc(&pdev->dev, sizeof(struct w1_bus_master),
133 GFP_KERNEL);
134 if (!master) {
135 dev_err(&pdev->dev, "Out of memory\n");
136 return -ENOMEM;
137 }
138
139 err = devm_gpio_request(&pdev->dev, pdata->pin, "w1");
140 if (err) {
141 dev_err(&pdev->dev, "gpio_request (pin) failed\n");
142 return err;
143 }
144
145 if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
146 err = devm_gpio_request_one(&pdev->dev,
147 pdata->ext_pullup_enable_pin, GPIOF_INIT_LOW,
148 "w1 pullup");
149 if (err < 0) {
150 dev_err(&pdev->dev, "gpio_request_one "
151 "(ext_pullup_enable_pin) failed\n");
152 return err;
153 }
154 }
155
156 master->data = pdata;
157 master->read_bit = w1_gpio_read_bit;
158
159 if (pdata->is_open_drain) {
160 gpio_direction_output(pdata->pin, 1);
161 master->write_bit = w1_gpio_write_bit_val;
162 } else {
163 gpio_direction_input(pdata->pin);
164 master->write_bit = w1_gpio_write_bit_dir;
165 master->set_pullup = w1_gpio_set_pullup;
166 }
167
168 err = w1_add_master_device(master);
169 if (err) {
170 dev_err(&pdev->dev, "w1_add_master device failed\n");
171 return err;
172 }
173
174 if (pdata->enable_external_pullup)
175 pdata->enable_external_pullup(1);
176
177 if (gpio_is_valid(pdata->ext_pullup_enable_pin))
178 gpio_set_value(pdata->ext_pullup_enable_pin, 1);
179
180 platform_set_drvdata(pdev, master);
181
182 return 0;
183}
184
185static int w1_gpio_remove(struct platform_device *pdev)
186{
187 struct w1_bus_master *master = platform_get_drvdata(pdev);
188 struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
189
190 if (pdata->enable_external_pullup)
191 pdata->enable_external_pullup(0);
192
193 if (gpio_is_valid(pdata->ext_pullup_enable_pin))
194 gpio_set_value(pdata->ext_pullup_enable_pin, 0);
195
196 w1_remove_master_device(master);
197
198 return 0;
199}
200
201static int __maybe_unused w1_gpio_suspend(struct device *dev)
202{
203 struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
204
205 if (pdata->enable_external_pullup)
206 pdata->enable_external_pullup(0);
207
208 return 0;
209}
210
211static int __maybe_unused w1_gpio_resume(struct device *dev)
212{
213 struct w1_gpio_platform_data *pdata = dev_get_platdata(dev);
214
215 if (pdata->enable_external_pullup)
216 pdata->enable_external_pullup(1);
217
218 return 0;
219}
220
221static SIMPLE_DEV_PM_OPS(w1_gpio_pm_ops, w1_gpio_suspend, w1_gpio_resume);
222
223static struct platform_driver w1_gpio_driver = {
224 .driver = {
225 .name = "w1-gpio",
226 .pm = &w1_gpio_pm_ops,
227 .of_match_table = of_match_ptr(w1_gpio_dt_ids),
228 },
229 .probe = w1_gpio_probe,
230 .remove = w1_gpio_remove,
231};
232
233module_platform_driver(w1_gpio_driver);
234
235MODULE_DESCRIPTION("GPIO w1 bus master driver");
236MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
237MODULE_LICENSE("GPL");
238
