diff options
Diffstat (limited to 'net/rfkill/rfkill-gpio.c')
| -rw-r--r-- | net/rfkill/rfkill-gpio.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c new file mode 100644 index 000000000000..256c5ddd2d72 --- /dev/null +++ b/net/rfkill/rfkill-gpio.c @@ -0,0 +1,227 @@ +/* + * Copyright (c) 2011, NVIDIA Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include <linux/gpio.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rfkill.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/slab.h> + +#include <linux/rfkill-gpio.h> + +enum rfkill_gpio_clk_state { + UNSPECIFIED = 0, + PWR_ENABLED, + PWR_DISABLED +}; + +#define PWR_CLK_SET(_RF, _EN) \ + ((_RF)->pwr_clk_enabled = (!(_EN) ? PWR_ENABLED : PWR_DISABLED)) +#define PWR_CLK_ENABLED(_RF) ((_RF)->pwr_clk_enabled == PWR_ENABLED) +#define PWR_CLK_DISABLED(_RF) ((_RF)->pwr_clk_enabled != PWR_ENABLED) + +struct rfkill_gpio_data { + struct rfkill_gpio_platform_data *pdata; + struct rfkill *rfkill_dev; + char *reset_name; + char *shutdown_name; + enum rfkill_gpio_clk_state pwr_clk_enabled; + struct clk *pwr_clk; +}; + +static int rfkill_gpio_set_power(void *data, bool blocked) +{ + struct rfkill_gpio_data *rfkill = data; + + if (blocked) { + if (gpio_is_valid(rfkill->pdata->shutdown_gpio)) + gpio_direction_output(rfkill->pdata->shutdown_gpio, 0); + if (gpio_is_valid(rfkill->pdata->reset_gpio)) + gpio_direction_output(rfkill->pdata->reset_gpio, 0); + if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill)) + clk_disable(rfkill->pwr_clk); + } else { + if (rfkill->pwr_clk && PWR_CLK_DISABLED(rfkill)) + clk_enable(rfkill->pwr_clk); + if (gpio_is_valid(rfkill->pdata->reset_gpio)) + gpio_direction_output(rfkill->pdata->reset_gpio, 1); + if (gpio_is_valid(rfkill->pdata->shutdown_gpio)) + gpio_direction_output(rfkill->pdata->shutdown_gpio, 1); + } + + if (rfkill->pwr_clk) + PWR_CLK_SET(rfkill, blocked); + + return 0; +} + +static const struct rfkill_ops rfkill_gpio_ops = { + .set_block = rfkill_gpio_set_power, +}; + +static int rfkill_gpio_probe(struct platform_device *pdev) +{ + struct rfkill_gpio_data *rfkill; + struct rfkill_gpio_platform_data *pdata = pdev->dev.platform_data; + int ret = 0; + int len = 0; + + if (!pdata) { + pr_warn("%s: No platform data specified\n", __func__); + return -EINVAL; + } + + /* make sure at-least one of the GPIO is defined and that + * a name is specified for this instance */ + if (!pdata->name || (!gpio_is_valid(pdata->reset_gpio) && + !gpio_is_valid(pdata->shutdown_gpio))) { + pr_warn("%s: invalid platform data\n", __func__); + return -EINVAL; + } + + rfkill = kzalloc(sizeof(*rfkill), GFP_KERNEL); + if (!rfkill) + return -ENOMEM; + + rfkill->pdata = pdata; + + len = strlen(pdata->name); + rfkill->reset_name = kzalloc(len + 7, GFP_KERNEL); + if (!rfkill->reset_name) { + ret = -ENOMEM; + goto fail_alloc; + } + + rfkill->shutdown_name = kzalloc(len + 10, GFP_KERNEL); + if (!rfkill->shutdown_name) { + ret = -ENOMEM; + goto fail_reset_name; + } + + snprintf(rfkill->reset_name, len + 6 , "%s_reset", pdata->name); + snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", pdata->name); + + if (pdata->power_clk_name) { + rfkill->pwr_clk = clk_get(&pdev->dev, pdata->power_clk_name); + if (IS_ERR(rfkill->pwr_clk)) { + pr_warn("%s: can't find pwr_clk.\n", __func__); + goto fail_shutdown_name; + } + } + + if (gpio_is_valid(pdata->reset_gpio)) { + ret = gpio_request(pdata->reset_gpio, rfkill->reset_name); + if (ret) { + pr_warn("%s: failed to get reset gpio.\n", __func__); + goto fail_clock; + } + } + + if (gpio_is_valid(pdata->shutdown_gpio)) { + ret = gpio_request(pdata->shutdown_gpio, rfkill->shutdown_name); + if (ret) { + pr_warn("%s: failed to get shutdown gpio.\n", __func__); + goto fail_reset; + } + } + + rfkill->rfkill_dev = rfkill_alloc(pdata->name, &pdev->dev, pdata->type, + &rfkill_gpio_ops, rfkill); + if (!rfkill->rfkill_dev) + goto fail_shutdown; + + ret = rfkill_register(rfkill->rfkill_dev); + if (ret < 0) + goto fail_rfkill; + + platform_set_drvdata(pdev, rfkill); + + dev_info(&pdev->dev, "%s device registered.\n", pdata->name); + + return 0; + +fail_rfkill: + rfkill_destroy(rfkill->rfkill_dev); +fail_shutdown: + if (gpio_is_valid(pdata->shutdown_gpio)) + gpio_free(pdata->shutdown_gpio); +fail_reset: + if (gpio_is_valid(pdata->reset_gpio)) + gpio_free(pdata->reset_gpio); +fail_clock: + if (rfkill->pwr_clk) + clk_put(rfkill->pwr_clk); +fail_shutdown_name: + kfree(rfkill->shutdown_name); +fail_reset_name: + kfree(rfkill->reset_name); +fail_alloc: + kfree(rfkill); + + return ret; +} + +static int rfkill_gpio_remove(struct platform_device *pdev) +{ + struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev); + + rfkill_unregister(rfkill->rfkill_dev); + rfkill_destroy(rfkill->rfkill_dev); + if (gpio_is_valid(rfkill->pdata->shutdown_gpio)) + gpio_free(rfkill->pdata->shutdown_gpio); + if (gpio_is_valid(rfkill->pdata->reset_gpio)) + gpio_free(rfkill->pdata->reset_gpio); + if (rfkill->pwr_clk && PWR_CLK_ENABLED(rfkill)) + clk_disable(rfkill->pwr_clk); + if (rfkill->pwr_clk) + clk_put(rfkill->pwr_clk); + kfree(rfkill->shutdown_name); + kfree(rfkill->reset_name); + kfree(rfkill); + + return 0; +} + +static struct platform_driver rfkill_gpio_driver = { + .probe = rfkill_gpio_probe, + .remove = __devexit_p(rfkill_gpio_remove), + .driver = { + .name = "rfkill_gpio", + .owner = THIS_MODULE, + }, +}; + +static int __init rfkill_gpio_init(void) +{ + return platform_driver_register(&rfkill_gpio_driver); +} + +static void __exit rfkill_gpio_exit(void) +{ + platform_driver_unregister(&rfkill_gpio_driver); +} + +module_init(rfkill_gpio_init); +module_exit(rfkill_gpio_exit); + +MODULE_DESCRIPTION("gpio rfkill"); +MODULE_AUTHOR("NVIDIA"); +MODULE_LICENSE("GPL"); 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