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         rfkill->pdata = pdata;
 105
 106         len = strlen(pdata->name);
 107         rfkill->reset_name = kzalloc(len + 7, GFP_KERNEL);
 108         if (!rfkill->reset_name) {
 109                 ret = -ENOMEM;
 110                 goto fail_alloc;
 111         }
 112
 113         rfkill->shutdown_name = kzalloc(len + 10, GFP_KERNEL);
 114         if (!rfkill->shutdown_name) {
 115                 ret = -ENOMEM;
 116                 goto fail_reset_name;
 117         }
 118
 119         snprintf(rfkill->reset_name, len + 6 , "%s_reset", pdata->name);
 120         snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", pdata->name);
 121
 122         if (pdata->power_clk_name) {
 123                 rfkill->pwr_clk = clk_get(&pdev->dev, pdata->power_clk_name);
 124                 if (IS_ERR(rfkill->pwr_clk)) {
 125                         pr_warn("%s: can't find pwr_clk.\n", __func__);
 126                         goto fail_shutdown_name;
 127                 }
 128         }
 129
 130         if (gpio_is_valid(pdata->reset_gpio)) {
 131                 ret = gpio_request(pdata->reset_gpio, rfkill->reset_name);
 132                 if (ret) {
 133                         pr_warn("%s: failed to get reset gpio.\n", __func__);
 134                         goto fail_clock;
 135                 }
 136         }
 137
 138         if (gpio_is_valid(pdata->shutdown_gpio)) {
 139                 ret = gpio_request(pdata->shutdown_gpio, rfkill->shutdown_name);
 140                 if (ret) {
 141                         pr_warn("%s: failed to get shutdown gpio.\n", __func__);
 142                         goto fail_reset;
 143                 }
 144         }
 145
 146         rfkill->rfkill_dev = rfkill_alloc(pdata->name, &pdev->dev, pdata->type,
 147                                 &rfkill_gpio_ops, rfkill);
 148         if (!rfkill->rfkill_dev)
 149                 goto fail_shutdown;
 150
 151         ret = rfkill_register(rfkill->rfkill_dev);
 152         if (ret < 0)
 153                 goto fail_rfkill;
 154
 155         platform_set_drvdata(pdev, rfkill);
 156
 157         dev_info(&pdev->dev, "%s device registered.\n", pdata->name);
 158
 159         return 0;
 160
 161 fail_rfkill:
 162         rfkill_destroy(rfkill->rfkill_dev);
 163 fail_shutdown:
 164         if (gpio_is_valid(pdata->shutdown_gpio))
 165                 gpio_free(pdata->shutdown_gpio);
 166 fail_reset:
 167         if (gpio_is_valid(pdata->reset_gpio))
 168                 gpio_free(pdata->reset_gpio);
 169 fail_clock:
 170         if (rfkill->pwr_clk)
 171                 clk_put(rfkill->pwr_clk);
 172 fail_shutdown_name:
 173         kfree(rfkill->shutdown_name);
 174 fail_reset_name:
 175         kfree(rfkill->reset_name);
 176 fail_alloc:
 177         kfree(rfkill);
 178
 179         return ret;
 180 }
 181
 182 static int rfkill_gpio_remove(struct platform_device *pdev)
 183 {
 184         struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
 185
 186         rfkill_unregister(rfkill->rfkill_dev);
 187         rfkill_destroy(rfkill->rfkill_dev);
 188         if (gpio_is_valid(rfkill->pdata->shutdown_gpio))
 189                 gpio_free(rfkill->pdata->shutdown_gpio);
 190         if (gpio_is_valid(rfkill->pdata->reset_gpio))
 191                 gpio_free(rfkill->pdata->reset_gpio);
 192         if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill))
 193                 clk_disable(rfkill->pwr_clk);
 194         if (rfkill->pwr_clk)
 195                 clk_put(rfkill->pwr_clk);
 196         kfree(rfkill->shutdown_name);
 197         kfree(rfkill->reset_name);
 198         kfree(rfkill);
 199
 200         return 0;
 201 }
 202
 203 static struct platform_driver rfkill_gpio_driver = {
 204         .probe = rfkill_gpio_probe,
 205         .remove = __devexit_p(rfkill_gpio_remove),
 206         .driver = {
 207                    .name = "rfkill_gpio",
 208                    .owner = THIS_MODULE,
 209         },
 210 };
 211
 212 static int __init rfkill_gpio_init(void)
 213 {
 214         return platform_driver_register(&rfkill_gpio_driver);
 215 }
 216
 217 static void __exit rfkill_gpio_exit(void)
 218 {
 219         platform_driver_unregister(&rfkill_gpio_driver);
 220 }
 221
 222 module_init(rfkill_gpio_init);
 223 module_exit(rfkill_gpio_exit);
 224
 225 MODULE_DESCRIPTION("gpio rfkill");
 226 MODULE_AUTHOR("NVIDIA");
 227 MODULE_LICENSE("GPL");