diff options
Diffstat (limited to 'drivers/staging/comedi/drivers/addi_watchdog.c')
| -rw-r--r-- | drivers/staging/comedi/drivers/addi_watchdog.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers/addi_watchdog.c b/drivers/staging/comedi/drivers/addi_watchdog.c new file mode 100644 index 00000000000..375ab665e09 --- /dev/null +++ b/drivers/staging/comedi/drivers/addi_watchdog.c @@ -0,0 +1,172 @@ +/* + * COMEDI driver for the watchdog subdevice found on some addi-data boards + * Copyright (c) 2013 H Hartley Sweeten <hsweeten@visionengravers.com> + * + * Based on implementations in various addi-data COMEDI drivers. + * + * COMEDI - Linux Control and Measurement Device Interface + * Copyright (C) 1998 David A. Schleef <ds@schleef.org> + * + * 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. + */ + +#include "../comedidev.h" +#include "addi_watchdog.h" + +/* + * Register offsets/defines for the addi-data watchdog + */ +#define ADDI_WDOG_REG 0x00 +#define ADDI_WDOG_RELOAD_REG 0x04 +#define ADDI_WDOG_TIMEBASE 0x08 +#define ADDI_WDOG_CTRL_REG 0x0c +#define ADDI_WDOG_CTRL_ENABLE (1 << 0) +#define ADDI_WDOG_CTRL_SW_TRIG (1 << 9) +#define ADDI_WDOG_STATUS_REG 0x10 +#define ADDI_WDOG_STATUS_ENABLED (1 << 0) +#define ADDI_WDOG_STATUS_SW_TRIG (1 << 1) + +struct addi_watchdog_private { + unsigned long iobase; + unsigned int wdog_ctrl; +}; + +/* + * The watchdog subdevice is configured with two INSN_CONFIG instructions: + * + * Enable the watchdog and set the reload timeout: + * data[0] = INSN_CONFIG_ARM + * data[1] = timeout reload value + * + * Disable the watchdog: + * data[0] = INSN_CONFIG_DISARM + */ +static int addi_watchdog_insn_config(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data) +{ + struct addi_watchdog_private *spriv = s->private; + unsigned int reload; + + switch (data[0]) { + case INSN_CONFIG_ARM: + spriv->wdog_ctrl = ADDI_WDOG_CTRL_ENABLE; + reload = data[1] & s->maxdata; + outl(reload, spriv->iobase + ADDI_WDOG_RELOAD_REG); + + /* Time base is 20ms, let the user know the timeout */ + dev_info(dev->class_dev, "watchdog enabled, timeout:%dms\n", + 20 * reload + 20); + break; + case INSN_CONFIG_DISARM: + spriv->wdog_ctrl = 0; + break; + default: + return -EINVAL; + } + + outl(spriv->wdog_ctrl, spriv->iobase + ADDI_WDOG_CTRL_REG); + + return insn->n; +} + +static int addi_watchdog_insn_read(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data) +{ + struct addi_watchdog_private *spriv = s->private; + int i; + + for (i = 0; i < insn->n; i++) + data[i] = inl(spriv->iobase + ADDI_WDOG_STATUS_REG); + + return insn->n; +} + +static int addi_watchdog_insn_write(struct comedi_device *dev, + struct comedi_subdevice *s, + struct comedi_insn *insn, + unsigned int *data) +{ + struct addi_watchdog_private *spriv = s->private; + int i; + + if (spriv->wdog_ctrl == 0) { + dev_warn(dev->class_dev, "watchdog is disabled\n"); + return -EINVAL; + } + + /* "ping" the watchdog */ + for (i = 0; i < insn->n; i++) { + outl(spriv->wdog_ctrl | ADDI_WDOG_CTRL_SW_TRIG, + spriv->iobase + ADDI_WDOG_CTRL_REG); + } + + return insn->n; +} + +void addi_watchdog_reset(unsigned long iobase) +{ + outl(0x0, iobase + ADDI_WDOG_CTRL_REG); + outl(0x0, iobase + ADDI_WDOG_RELOAD_REG); +} +EXPORT_SYMBOL_GPL(addi_watchdog_reset); + +int addi_watchdog_init(struct comedi_subdevice *s, unsigned long iobase) +{ + struct addi_watchdog_private *spriv; + + spriv = kzalloc(sizeof(*spriv), GFP_KERNEL); + if (!spriv) + return -ENOMEM; + + spriv->iobase = iobase; + + s->private = spriv; + + s->type = COMEDI_SUBD_TIMER; + s->subdev_flags = SDF_WRITEABLE; + s->n_chan = 1; + s->maxdata = 0xff; + s->insn_config = addi_watchdog_insn_config; + s->insn_read = addi_watchdog_insn_read; + s->insn_write = addi_watchdog_insn_write; + + return 0; +} +EXPORT_SYMBOL_GPL(addi_watchdog_init); + +void addi_watchdog_cleanup(struct comedi_subdevice *s) +{ + kfree(s->private); +} +EXPORT_SYMBOL_GPL(addi_watchdog_cleanup); + +static int __init addi_watchdog_module_init(void) +{ + return 0; +} +module_init(addi_watchdog_module_init); + +static void __exit addi_watchdog_module_exit(void) +{ +} +module_exit(addi_watchdog_module_exit); + +MODULE_DESCRIPTION("ADDI-DATA Watchdog subdevice"); +MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>"); +MODULE_LICENSE("GPL"); |