diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-11-02 16:07:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-11-02 16:07:27 -0700 |
commit | 092f4c56c1927e4b61a41ee8055005f1cb437009 (patch) | |
tree | 616ceb54b7671ccc13922ae9e002b8b972f6e09e /drivers/pps/clients/pps-gpio.c | |
parent | 80c2861672bbf000f6af838656959ee937e4ee4d (diff) | |
parent | c1e2ee2dc436574880758b3836fc96935b774c32 (diff) | |
download | op-kernel-dev-092f4c56c1927e4b61a41ee8055005f1cb437009.zip op-kernel-dev-092f4c56c1927e4b61a41ee8055005f1cb437009.tar.gz |
Merge branch 'akpm' (Andrew's incoming - part two)
Says Andrew:
"60 patches. That's good enough for -rc1 I guess. I have quite a lot
of detritus to be rechecked, work through maintainers, etc.
- most of the remains of MM
- rtc
- various misc
- cgroups
- memcg
- cpusets
- procfs
- ipc
- rapidio
- sysctl
- pps
- w1
- drivers/misc
- aio"
* akpm: (60 commits)
memcg: replace ss->id_lock with a rwlock
aio: allocate kiocbs in batches
drivers/misc/vmw_balloon.c: fix typo in code comment
drivers/misc/vmw_balloon.c: determine page allocation flag can_sleep outside loop
w1: disable irqs in critical section
drivers/w1/w1_int.c: multiple masters used same init_name
drivers/power/ds2780_battery.c: fix deadlock upon insertion and removal
drivers/power/ds2780_battery.c: add a nolock function to w1 interface
drivers/power/ds2780_battery.c: create central point for calling w1 interface
w1: ds2760 and ds2780, use ida for id and ida_simple_get() to get it
pps gpio client: add missing dependency
pps: new client driver using GPIO
pps: default echo function
include/linux/dma-mapping.h: add dma_zalloc_coherent()
sysctl: make CONFIG_SYSCTL_SYSCALL default to n
sysctl: add support for poll()
RapidIO: documentation update
drivers/net/rionet.c: fix ethernet address macros for LE platforms
RapidIO: fix potential null deref in rio_setup_device()
RapidIO: add mport driver for Tsi721 bridge
...
Diffstat (limited to 'drivers/pps/clients/pps-gpio.c')
-rw-r--r-- | drivers/pps/clients/pps-gpio.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/pps/clients/pps-gpio.c b/drivers/pps/clients/pps-gpio.c new file mode 100644 index 0000000..6550555 --- /dev/null +++ b/drivers/pps/clients/pps-gpio.c @@ -0,0 +1,227 @@ +/* + * pps-gpio.c -- PPS client driver using GPIO + * + * + * Copyright (C) 2010 Ricardo Martins <rasm@fe.up.pt> + * Copyright (C) 2011 James Nuss <jamesnuss@nanometrics.ca> + * + * 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., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#define PPS_GPIO_NAME "pps-gpio" +#define pr_fmt(fmt) PPS_GPIO_NAME ": " fmt + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/pps_kernel.h> +#include <linux/pps-gpio.h> +#include <linux/gpio.h> +#include <linux/list.h> + +/* Info for each registered platform device */ +struct pps_gpio_device_data { + int irq; /* IRQ used as PPS source */ + struct pps_device *pps; /* PPS source device */ + struct pps_source_info info; /* PPS source information */ + const struct pps_gpio_platform_data *pdata; +}; + +/* + * Report the PPS event + */ + +static irqreturn_t pps_gpio_irq_handler(int irq, void *data) +{ + const struct pps_gpio_device_data *info; + struct pps_event_time ts; + int rising_edge; + + /* Get the time stamp first */ + pps_get_ts(&ts); + + info = data; + + rising_edge = gpio_get_value(info->pdata->gpio_pin); + if ((rising_edge && !info->pdata->assert_falling_edge) || + (!rising_edge && info->pdata->assert_falling_edge)) + pps_event(info->pps, &ts, PPS_CAPTUREASSERT, NULL); + else if (info->pdata->capture_clear && + ((rising_edge && info->pdata->assert_falling_edge) || + (!rising_edge && !info->pdata->assert_falling_edge))) + pps_event(info->pps, &ts, PPS_CAPTURECLEAR, NULL); + + return IRQ_HANDLED; +} + +static int pps_gpio_setup(struct platform_device *pdev) +{ + int ret; + const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data; + + ret = gpio_request(pdata->gpio_pin, pdata->gpio_label); + if (ret) { + pr_warning("failed to request GPIO %u\n", pdata->gpio_pin); + return -EINVAL; + } + + ret = gpio_direction_input(pdata->gpio_pin); + if (ret) { + pr_warning("failed to set pin direction\n"); + gpio_free(pdata->gpio_pin); + return -EINVAL; + } + + return 0; +} + +static unsigned long +get_irqf_trigger_flags(const struct pps_gpio_platform_data *pdata) +{ + unsigned long flags = pdata->assert_falling_edge ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; + + if (pdata->capture_clear) { + flags |= ((flags & IRQF_TRIGGER_RISING) ? + IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING); + } + + return flags; +} + +static int pps_gpio_probe(struct platform_device *pdev) +{ + struct pps_gpio_device_data *data; + int irq; + int ret; + int err; + int pps_default_params; + const struct pps_gpio_platform_data *pdata = pdev->dev.platform_data; + + + /* GPIO setup */ + ret = pps_gpio_setup(pdev); + if (ret) + return -EINVAL; + + /* IRQ setup */ + irq = gpio_to_irq(pdata->gpio_pin); + if (irq < 0) { + pr_err("failed to map GPIO to IRQ: %d\n", irq); + err = -EINVAL; + goto return_error; + } + + /* allocate space for device info */ + data = kzalloc(sizeof(struct pps_gpio_device_data), GFP_KERNEL); + if (data == NULL) { + err = -ENOMEM; + goto return_error; + } + + /* initialize PPS specific parts of the bookkeeping data structure. */ + data->info.mode = PPS_CAPTUREASSERT | PPS_OFFSETASSERT | + PPS_ECHOASSERT | PPS_CANWAIT | PPS_TSFMT_TSPEC; + if (pdata->capture_clear) + data->info.mode |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR | + PPS_ECHOCLEAR; + data->info.owner = THIS_MODULE; + snprintf(data->info.name, PPS_MAX_NAME_LEN - 1, "%s.%d", + pdev->name, pdev->id); + + /* register PPS source */ + pps_default_params = PPS_CAPTUREASSERT | PPS_OFFSETASSERT; + if (pdata->capture_clear) + pps_default_params |= PPS_CAPTURECLEAR | PPS_OFFSETCLEAR; + data->pps = pps_register_source(&data->info, pps_default_params); + if (data->pps == NULL) { + kfree(data); + pr_err("failed to register IRQ %d as PPS source\n", irq); + err = -EINVAL; + goto return_error; + } + + data->irq = irq; + data->pdata = pdata; + + /* register IRQ interrupt handler */ + ret = request_irq(irq, pps_gpio_irq_handler, + get_irqf_trigger_flags(pdata), data->info.name, data); + if (ret) { + pps_unregister_source(data->pps); + kfree(data); + pr_err("failed to acquire IRQ %d\n", irq); + err = -EINVAL; + goto return_error; + } + + platform_set_drvdata(pdev, data); + dev_info(data->pps->dev, "Registered IRQ %d as PPS source\n", irq); + + return 0; + +return_error: + gpio_free(pdata->gpio_pin); + return err; +} + +static int pps_gpio_remove(struct platform_device *pdev) +{ + struct pps_gpio_device_data *data = platform_get_drvdata(pdev); + const struct pps_gpio_platform_data *pdata = data->pdata; + + platform_set_drvdata(pdev, NULL); + free_irq(data->irq, data); + gpio_free(pdata->gpio_pin); + pps_unregister_source(data->pps); + pr_info("removed IRQ %d as PPS source\n", data->irq); + kfree(data); + return 0; +} + +static struct platform_driver pps_gpio_driver = { + .probe = pps_gpio_probe, + .remove = __devexit_p(pps_gpio_remove), + .driver = { + .name = PPS_GPIO_NAME, + .owner = THIS_MODULE + }, +}; + +static int __init pps_gpio_init(void) +{ + int ret = platform_driver_register(&pps_gpio_driver); + if (ret < 0) + pr_err("failed to register platform driver\n"); + return ret; +} + +static void __exit pps_gpio_exit(void) +{ + platform_driver_unregister(&pps_gpio_driver); + pr_debug("unregistered platform driver\n"); +} + +module_init(pps_gpio_init); +module_exit(pps_gpio_exit); + +MODULE_AUTHOR("Ricardo Martins <rasm@fe.up.pt>"); +MODULE_AUTHOR("James Nuss <jamesnuss@nanometrics.ca>"); +MODULE_DESCRIPTION("Use GPIO pin as PPS source"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1.0.0"); |