linux/net/rfkill/rfkill-gpio.c
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   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
  30enum 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
  41struct 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
  50static 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
  76static const struct rfkill_ops rfkill_gpio_ops = {
  77        .set_block = rfkill_gpio_set_power,
  78};
  79
  80static 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
 169fail_rfkill:
 170        rfkill_destroy(rfkill->rfkill_dev);
 171fail_shutdown:
 172        if (gpio_is_valid(pdata->shutdown_gpio))
 173                gpio_free(pdata->shutdown_gpio);
 174fail_reset:
 175        if (gpio_is_valid(pdata->reset_gpio))
 176                gpio_free(pdata->reset_gpio);
 177fail_clock:
 178        if (rfkill->pwr_clk)
 179                clk_put(rfkill->pwr_clk);
 180fail_shutdown_name:
 181        kfree(rfkill->shutdown_name);
 182fail_reset_name:
 183        kfree(rfkill->reset_name);
 184fail_alloc:
 185        kfree(rfkill);
 186
 187        return ret;
 188}
 189
 190static 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
 214static 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
 223module_platform_driver(rfkill_gpio_driver);
 224
 225MODULE_DESCRIPTION("gpio rfkill");
 226MODULE_AUTHOR("NVIDIA");
 227MODULE_LICENSE("GPL");
 228
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