linux/drivers/mfd/pcf50633-adc.c

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/* NXP PCF50633 ADC Driver
*
* (C) 2006-2008 by Openmoko, Inc.
* Author: Balaji Rao <balajirrao@openmoko.org>
* All rights reserved.
*
* Broken down from monstrous PCF50633 driver mainly by
* Harald Welte, Andy Green and Werner Almesberger
*
* 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.
*
* NOTE: This driver does not yet support subtractive ADC mode, which means
* you can do only one measurement per read request.
*/
#include <linux/kernel.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 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/completion.h>
#include <linux/mfd/pcf50633/core.h>
#include <linux/mfd/pcf50633/adc.h>
struct pcf50633_adc_request {
int mux;
int avg;
void (*callback)(struct pcf50633 *, void *, int);
void *callback_param;
};
struct pcf50633_adc_sync_request {
int result;
struct completion completion;
};
#define PCF50633_MAX_ADC_FIFO_DEPTH 8
struct pcf50633_adc {
struct pcf50633 *pcf;
/* Private stuff */
struct pcf50633_adc_request *queue[PCF50633_MAX_ADC_FIFO_DEPTH];
int queue_head;
int queue_tail;
struct mutex queue_mutex;
};
static inline struct pcf50633_adc *__to_adc(struct pcf50633 *pcf)
{
return platform_get_drvdata(pcf->adc_pdev);
}
static void adc_setup(struct pcf50633 *pcf, int channel, int avg)
{
channel &= PCF50633_ADCC1_ADCMUX_MASK;
/* kill ratiometric, but enable ACCSW biasing */
pcf50633_reg_write(pcf, PCF50633_REG_ADCC2, 0x00);
pcf50633_reg_write(pcf, PCF50633_REG_ADCC3, 0x01);
/* start ADC conversion on selected channel */
pcf50633_reg_write(pcf, PCF50633_REG_ADCC1, channel | avg |
PCF50633_ADCC1_ADCSTART | PCF50633_ADCC1_RES_10BIT);
}
static void trigger_next_adc_job_if_any(struct pcf50633 *pcf)
{
struct pcf50633_adc *adc = __to_adc(pcf);
int head;
head = adc->queue_head;
if (!adc->queue[head])
return;
adc_setup(pcf, adc->queue[head]->mux, adc->queue[head]->avg);
}
static int
adc_enqueue_request(struct pcf50633 *pcf, struct pcf50633_adc_request *req)
{
struct pcf50633_adc *adc = __to_adc(pcf);
int head, tail;
mutex_lock(&adc->queue_mutex);
head = adc->queue_head;
tail = adc->queue_tail;
if (adc->queue[tail]) {
mutex_unlock(&adc->queue_mutex);
dev_err(pcf->dev, "ADC queue is full, dropping request\n");
return -EBUSY;
}
adc->queue[tail] = req;
if (head == tail)
trigger_next_adc_job_if_any(pcf);
adc->queue_tail = (tail + 1) & (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
mutex_unlock(&adc->queue_mutex);
return 0;
}
static void pcf50633_adc_sync_read_callback(struct pcf50633 *pcf, void *param,
int result)
{
struct pcf50633_adc_sync_request *req = param;
req->result = result;
complete(&req->completion);
}
int pcf50633_adc_sync_read(struct pcf50633 *pcf, int mux, int avg)
{
struct pcf50633_adc_sync_request req;
int ret;
init_completion(&req.completion);
ret = pcf50633_adc_async_read(pcf, mux, avg,
pcf50633_adc_sync_read_callback, &req);
if (ret)
return ret;
wait_for_completion(&req.completion);
return req.result;
}
EXPORT_SYMBOL_GPL(pcf50633_adc_sync_read);
int pcf50633_adc_async_read(struct pcf50633 *pcf, int mux, int avg,
void (*callback)(struct pcf50633 *, void *, int),
void *callback_param)
{
struct pcf50633_adc_request *req;
/* req is freed when the result is ready, in interrupt handler */
req = kmalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
req->mux = mux;
req->avg = avg;
req->callback = callback;
req->callback_param = callback_param;
return adc_enqueue_request(pcf, req);
}
EXPORT_SYMBOL_GPL(pcf50633_adc_async_read);
static int adc_result(struct pcf50633 *pcf)
{
u8 adcs1, adcs3;
u16 result;
adcs1 = pcf50633_reg_read(pcf, PCF50633_REG_ADCS1);
adcs3 = pcf50633_reg_read(pcf, PCF50633_REG_ADCS3);
result = (adcs1 << 2) | (adcs3 & PCF50633_ADCS3_ADCDAT1L_MASK);
dev_dbg(pcf->dev, "adc result = %d\n", result);
return result;
}
static void pcf50633_adc_irq(int irq, void *data)
{
struct pcf50633_adc *adc = data;
struct pcf50633 *pcf = adc->pcf;
struct pcf50633_adc_request *req;
int head, res;
mutex_lock(&adc->queue_mutex);
head = adc->queue_head;
req = adc->queue[head];
if (WARN_ON(!req)) {
dev_err(pcf->dev, "pcf50633-adc irq: ADC queue empty!\n");
mutex_unlock(&adc->queue_mutex);
return;
}
adc->queue[head] = NULL;
adc->queue_head = (head + 1) &
(PCF50633_MAX_ADC_FIFO_DEPTH - 1);
res = adc_result(pcf);
trigger_next_adc_job_if_any(pcf);
mutex_unlock(&adc->queue_mutex);
req->callback(pcf, req->callback_param, res);
kfree(req);
}
static int pcf50633_adc_probe(struct platform_device *pdev)
{
struct pcf50633_adc *adc;
adc = devm_kzalloc(&pdev->dev, sizeof(*adc), GFP_KERNEL);
if (!adc)
return -ENOMEM;
adc->pcf = dev_to_pcf50633(pdev->dev.parent);
platform_set_drvdata(pdev, adc);
pcf50633_register_irq(adc->pcf, PCF50633_IRQ_ADCRDY,
pcf50633_adc_irq, adc);
mutex_init(&adc->queue_mutex);
return 0;
}
static int pcf50633_adc_remove(struct platform_device *pdev)
{
struct pcf50633_adc *adc = platform_get_drvdata(pdev);
int i, head;
pcf50633_free_irq(adc->pcf, PCF50633_IRQ_ADCRDY);
mutex_lock(&adc->queue_mutex);
head = adc->queue_head;
if (WARN_ON(adc->queue[head]))
dev_err(adc->pcf->dev,
"adc driver removed with request pending\n");
for (i = 0; i < PCF50633_MAX_ADC_FIFO_DEPTH; i++)
kfree(adc->queue[i]);
mutex_unlock(&adc->queue_mutex);
return 0;
}
static struct platform_driver pcf50633_adc_driver = {
.driver = {
.name = "pcf50633-adc",
},
.probe = pcf50633_adc_probe,
.remove = pcf50633_adc_remove,
};
module_platform_driver(pcf50633_adc_driver);
MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
MODULE_DESCRIPTION("PCF50633 adc driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcf50633-adc");