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
rfkill_gpio_set_power(void * data,bool blocked)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
rfkill_gpio_probe(struct platform_device * pdev)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
rfkill_gpio_remove(struct platform_device * pdev)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