linux/drivers/gpio/gpio-mc33880.c

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/*
* MC33880 high-side/low-side switch GPIO driver
* Copyright (c) 2009 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*/
/* Supports:
* Freescale MC33880 high-side/low-side switch
*/
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/spi/spi.h>
#include <linux/spi/mc33880.h>
#include <linux/gpio.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/module.h>
#define DRIVER_NAME "mc33880"
/*
* Pin configurations, see MAX7301 datasheet page 6
*/
#define PIN_CONFIG_MASK 0x03
#define PIN_CONFIG_IN_PULLUP 0x03
#define PIN_CONFIG_IN_WO_PULLUP 0x02
#define PIN_CONFIG_OUT 0x01
#define PIN_NUMBER 8
/*
* Some registers must be read back to modify.
* To save time we cache them here in memory
*/
struct mc33880 {
struct mutex lock; /* protect from simultaneous accesses */
u8 port_config;
struct gpio_chip chip;
struct spi_device *spi;
};
static int mc33880_write_config(struct mc33880 *mc)
{
return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
}
static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
{
if (value)
mc->port_config |= 1 << offset;
else
mc->port_config &= ~(1 << offset);
return mc33880_write_config(mc);
}
static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct mc33880 *mc = container_of(chip, struct mc33880, chip);
mutex_lock(&mc->lock);
__mc33880_set(mc, offset, value);
mutex_unlock(&mc->lock);
}
static int mc33880_probe(struct spi_device *spi)
{
struct mc33880 *mc;
struct mc33880_platform_data *pdata;
int ret;
pdata = dev_get_platdata(&spi->dev);
if (!pdata || !pdata->base) {
dev_dbg(&spi->dev, "incorrect or missing platform data\n");
return -EINVAL;
}
/*
* bits_per_word cannot be configured in platform data
*/
spi->bits_per_word = 8;
ret = spi_setup(spi);
if (ret < 0)
return ret;
mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
if (!mc)
return -ENOMEM;
mutex_init(&mc->lock);
spi_set_drvdata(spi, mc);
mc->spi = spi;
mc->chip.label = DRIVER_NAME,
mc->chip.set = mc33880_set;
mc->chip.base = pdata->base;
mc->chip.ngpio = PIN_NUMBER;
mc->chip.can_sleep = true;
mc->chip.dev = &spi->dev;
mc->chip.owner = THIS_MODULE;
mc->port_config = 0x00;
/* write twice, because during initialisation the first setting
* is just for testing SPI communication, and the second is the
* "real" configuration
*/
ret = mc33880_write_config(mc);
mc->port_config = 0x00;
if (!ret)
ret = mc33880_write_config(mc);
if (ret) {
dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
ret);
goto exit_destroy;
}
ret = gpiochip_add(&mc->chip);
if (ret)
goto exit_destroy;
return ret;
exit_destroy:
mutex_destroy(&mc->lock);
return ret;
}
static int mc33880_remove(struct spi_device *spi)
{
struct mc33880 *mc;
mc = spi_get_drvdata(spi);
if (mc == NULL)
return -ENODEV;
gpiochip_remove(&mc->chip);
mutex_destroy(&mc->lock);
return 0;
}
static struct spi_driver mc33880_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.probe = mc33880_probe,
.remove = mc33880_remove,
};
static int __init mc33880_init(void)
{
return spi_register_driver(&mc33880_driver);
}
/* register after spi postcore initcall and before
* subsys initcalls that may rely on these GPIOs
*/
subsys_initcall(mc33880_init);
static void __exit mc33880_exit(void)
{
spi_unregister_driver(&mc33880_driver);
}
module_exit(mc33880_exit);
MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
MODULE_LICENSE("GPL v2");