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