Merge tag 'uas_for_sarah' of git://linutronix.de/users/bigeasy/linux into for-uas...
[firefly-linux-kernel-4.4.55.git] / net / rfkill / rfkill-gpio.c
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");