xref: /openbmc/linux/net/rfkill/rfkill-gpio.c (revision 95e9fd10)
1 /*
2  * Copyright (c) 2011, NVIDIA Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along
15  * with this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17  */
18 
19 #include <linux/gpio.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/rfkill.h>
24 #include <linux/platform_device.h>
25 #include <linux/clk.h>
26 #include <linux/slab.h>
27 
28 #include <linux/rfkill-gpio.h>
29 
30 enum rfkill_gpio_clk_state {
31 	UNSPECIFIED = 0,
32 	PWR_ENABLED,
33 	PWR_DISABLED
34 };
35 
36 #define PWR_CLK_SET(_RF, _EN) \
37 	((_RF)->pwr_clk_enabled = (!(_EN) ? PWR_ENABLED : PWR_DISABLED))
38 #define PWR_CLK_ENABLED(_RF) ((_RF)->pwr_clk_enabled == PWR_ENABLED)
39 #define PWR_CLK_DISABLED(_RF) ((_RF)->pwr_clk_enabled != PWR_ENABLED)
40 
41 struct rfkill_gpio_data {
42 	struct rfkill_gpio_platform_data	*pdata;
43 	struct rfkill				*rfkill_dev;
44 	char					*reset_name;
45 	char					*shutdown_name;
46 	enum rfkill_gpio_clk_state		pwr_clk_enabled;
47 	struct clk				*pwr_clk;
48 };
49 
50 static int rfkill_gpio_set_power(void *data, bool blocked)
51 {
52 	struct rfkill_gpio_data *rfkill = data;
53 
54 	if (blocked) {
55 		if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
56 			gpio_direction_output(rfkill->pdata->shutdown_gpio, 0);
57 		if (gpio_is_valid(rfkill->pdata->reset_gpio))
58 			gpio_direction_output(rfkill->pdata->reset_gpio, 0);
59 		if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill))
60 			clk_disable(rfkill->pwr_clk);
61 	} else {
62 		if (rfkill->pwr_clk && PWR_CLK_DISABLED(rfkill))
63 			clk_enable(rfkill->pwr_clk);
64 		if (gpio_is_valid(rfkill->pdata->reset_gpio))
65 			gpio_direction_output(rfkill->pdata->reset_gpio, 1);
66 		if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
67 			gpio_direction_output(rfkill->pdata->shutdown_gpio, 1);
68 	}
69 
70 	if (rfkill->pwr_clk)
71 		PWR_CLK_SET(rfkill, blocked);
72 
73 	return 0;
74 }
75 
76 static const struct rfkill_ops rfkill_gpio_ops = {
77 	.set_block = rfkill_gpio_set_power,
78 };
79 
80 static int rfkill_gpio_probe(struct platform_device *pdev)
81 {
82 	struct rfkill_gpio_data *rfkill;
83 	struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
84 	int ret = 0;
85 	int len = 0;
86 
87 	if (!pdata) {
88 		pr_warn("%s: No platform data specified\n", __func__);
89 		return -EINVAL;
90 	}
91 
92 	/* make sure at-least one of the GPIO is defined and that
93 	 * a name is specified for this instance */
94 	if (!pdata->name || (!gpio_is_valid(pdata->reset_gpio) &&
95 		!gpio_is_valid(pdata->shutdown_gpio))) {
96 		pr_warn("%s: invalid platform data\n", __func__);
97 		return -EINVAL;
98 	}
99 
100 	rfkill = kzalloc(sizeof(*rfkill), GFP_KERNEL);
101 	if (!rfkill)
102 		return -ENOMEM;
103 
104 	if (pdata->gpio_runtime_setup) {
105 		ret = pdata->gpio_runtime_setup(pdev);
106 		if (ret) {
107 			pr_warn("%s: can't set up gpio\n", __func__);
108 			goto fail_alloc;
109 		}
110 	}
111 
112 	rfkill->pdata = pdata;
113 
114 	len = strlen(pdata->name);
115 	rfkill->reset_name = kzalloc(len + 7, GFP_KERNEL);
116 	if (!rfkill->reset_name) {
117 		ret = -ENOMEM;
118 		goto fail_alloc;
119 	}
120 
121 	rfkill->shutdown_name = kzalloc(len + 10, GFP_KERNEL);
122 	if (!rfkill->shutdown_name) {
123 		ret = -ENOMEM;
124 		goto fail_reset_name;
125 	}
126 
127 	snprintf(rfkill->reset_name, len + 6 , "%s_reset", pdata->name);
128 	snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", pdata->name);
129 
130 	if (pdata->power_clk_name) {
131 		rfkill->pwr_clk = clk_get(&pdev->dev, pdata->power_clk_name);
132 		if (IS_ERR(rfkill->pwr_clk)) {
133 			pr_warn("%s: can't find pwr_clk.\n", __func__);
134 			goto fail_shutdown_name;
135 		}
136 	}
137 
138 	if (gpio_is_valid(pdata->reset_gpio)) {
139 		ret = gpio_request(pdata->reset_gpio, rfkill->reset_name);
140 		if (ret) {
141 			pr_warn("%s: failed to get reset gpio.\n", __func__);
142 			goto fail_clock;
143 		}
144 	}
145 
146 	if (gpio_is_valid(pdata->shutdown_gpio)) {
147 		ret = gpio_request(pdata->shutdown_gpio, rfkill->shutdown_name);
148 		if (ret) {
149 			pr_warn("%s: failed to get shutdown gpio.\n", __func__);
150 			goto fail_reset;
151 		}
152 	}
153 
154 	rfkill->rfkill_dev = rfkill_alloc(pdata->name, &pdev->dev, pdata->type,
155 				&rfkill_gpio_ops, rfkill);
156 	if (!rfkill->rfkill_dev)
157 		goto fail_shutdown;
158 
159 	ret = rfkill_register(rfkill->rfkill_dev);
160 	if (ret < 0)
161 		goto fail_rfkill;
162 
163 	platform_set_drvdata(pdev, rfkill);
164 
165 	dev_info(&pdev->dev, "%s device registered.\n", pdata->name);
166 
167 	return 0;
168 
169 fail_rfkill:
170 	rfkill_destroy(rfkill->rfkill_dev);
171 fail_shutdown:
172 	if (gpio_is_valid(pdata->shutdown_gpio))
173 		gpio_free(pdata->shutdown_gpio);
174 fail_reset:
175 	if (gpio_is_valid(pdata->reset_gpio))
176 		gpio_free(pdata->reset_gpio);
177 fail_clock:
178 	if (rfkill->pwr_clk)
179 		clk_put(rfkill->pwr_clk);
180 fail_shutdown_name:
181 	kfree(rfkill->shutdown_name);
182 fail_reset_name:
183 	kfree(rfkill->reset_name);
184 fail_alloc:
185 	kfree(rfkill);
186 
187 	return ret;
188 }
189 
190 static int rfkill_gpio_remove(struct platform_device *pdev)
191 {
192 	struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
193 	struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data;
194 
195 	if (pdata->gpio_runtime_close)
196 		pdata->gpio_runtime_close(pdev);
197 	rfkill_unregister(rfkill->rfkill_dev);
198 	rfkill_destroy(rfkill->rfkill_dev);
199 	if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
200 		gpio_free(rfkill->pdata->shutdown_gpio);
201 	if (gpio_is_valid(rfkill->pdata->reset_gpio))
202 		gpio_free(rfkill->pdata->reset_gpio);
203 	if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill))
204 		clk_disable(rfkill->pwr_clk);
205 	if (rfkill->pwr_clk)
206 		clk_put(rfkill->pwr_clk);
207 	kfree(rfkill->shutdown_name);
208 	kfree(rfkill->reset_name);
209 	kfree(rfkill);
210 
211 	return 0;
212 }
213 
214 static struct platform_driver rfkill_gpio_driver = {
215 	.probe = rfkill_gpio_probe,
216 	.remove = __devexit_p(rfkill_gpio_remove),
217 	.driver = {
218 		   .name = "rfkill_gpio",
219 		   .owner = THIS_MODULE,
220 	},
221 };
222 
223 module_platform_driver(rfkill_gpio_driver);
224 
225 MODULE_DESCRIPTION("gpio rfkill");
226 MODULE_AUTHOR("NVIDIA");
227 MODULE_LICENSE("GPL");
228