mfd: PCF50633 adc driver

This patch adds basic support for the PCF50633 ADC. The subtractive mode
is not supported yet.

Since we don't have adc subsystem, it currently lives in drivers/mfd.

Signed-off-by: Balaji Rao <balajirrao@openmoko.org>
Cc: Andy Green <andy@openmoko.com>
Acked-by: Jonathan Cameron <jonathan.cameron@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
This commit is contained in:
Balaji Rao 2009-01-09 01:49:26 +01:00 committed by Samuel Ortiz
parent f52046b14b
commit 08c3e06a5e
4 changed files with 358 additions and 1 deletions

View file

@ -226,6 +226,13 @@ config MFD_PCF50633
facilities, and registers devices for the various functions
so that function-specific drivers can bind to them.
config PCF50633_ADC
tristate "Support for NXP PCF50633 ADC"
depends on MFD_PCF50633
help
Say yes here if you want to include support for ADC in the
NXP PCF50633 chip.
endmenu
menu "Multimedia Capabilities Port drivers"

View file

@ -38,4 +38,5 @@ obj-$(CONFIG_UCB1400_CORE) += ucb1400_core.o
obj-$(CONFIG_PMIC_DA903X) += da903x.o
obj-$(CONFIG_MFD_PCF50633) += pcf50633-core.o
obj-$(CONFIG_MFD_PCF50633) += pcf50633-core.o
obj-$(CONFIG_PCF50633_ADC) += pcf50633-adc.o

277
drivers/mfd/pcf50633-adc.c Normal file
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@ -0,0 +1,277 @@
/* 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 <linux/module.h>
#include <linux/init.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;
int result;
void (*callback)(struct pcf50633 *, void *, int);
void *callback_param;
/* Used in case of sync requests */
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;
mutex_lock(&adc->queue_mutex);
head = adc->queue_head;
if (!adc->queue[head]) {
mutex_unlock(&adc->queue_mutex);
return;
}
mutex_unlock(&adc->queue_mutex);
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);
return -EBUSY;
}
adc->queue[tail] = req;
adc->queue_tail = (tail + 1) & (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
mutex_unlock(&adc->queue_mutex);
trigger_next_adc_job_if_any(pcf);
return 0;
}
static void
pcf50633_adc_sync_read_callback(struct pcf50633 *pcf, void *param, int result)
{
struct pcf50633_adc_request *req = param;
req->result = result;
complete(&req->completion);
}
int pcf50633_adc_sync_read(struct pcf50633 *pcf, int mux, int avg)
{
struct pcf50633_adc_request *req;
/* req is freed when the result is ready, in interrupt handler */
req = kzalloc(sizeof(*req), GFP_KERNEL);
if (!req)
return -ENOMEM;
req->mux = mux;
req->avg = avg;
req->callback = pcf50633_adc_sync_read_callback;
req->callback_param = req;
init_completion(&req->completion);
adc_enqueue_request(pcf, req);
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;
adc_enqueue_request(pcf, req);
return 0;
}
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;
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);
mutex_unlock(&adc->queue_mutex);
req->callback(pcf, req->callback_param, adc_result(pcf));
kfree(req);
trigger_next_adc_job_if_any(pcf);
}
static int __devinit pcf50633_adc_probe(struct platform_device *pdev)
{
struct pcf50633_subdev_pdata *pdata = pdev->dev.platform_data;
struct pcf50633_adc *adc;
adc = kzalloc(sizeof(*adc), GFP_KERNEL);
if (!adc)
return -ENOMEM;
adc->pcf = pdata->pcf;
platform_set_drvdata(pdev, adc);
pcf50633_register_irq(pdata->pcf, PCF50633_IRQ_ADCRDY,
pcf50633_adc_irq, adc);
mutex_init(&adc->queue_mutex);
return 0;
}
static int __devexit 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);
kfree(adc);
return 0;
}
static struct platform_driver pcf50633_adc_driver = {
.driver = {
.name = "pcf50633-adc",
},
.probe = pcf50633_adc_probe,
.remove = __devexit_p(pcf50633_adc_remove),
};
static int __init pcf50633_adc_init(void)
{
return platform_driver_register(&pcf50633_adc_driver);
}
module_init(pcf50633_adc_init);
static void __exit pcf50633_adc_exit(void)
{
platform_driver_unregister(&pcf50633_adc_driver);
}
module_exit(pcf50633_adc_exit);
MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
MODULE_DESCRIPTION("PCF50633 adc driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcf50633-adc");

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@ -0,0 +1,72 @@
/*
* adc.h -- Driver for NXP PCF50633 ADC
*
* (C) 2006-2008 by Openmoko, Inc.
* All rights reserved.
*
* 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.
*/
#ifndef __LINUX_MFD_PCF50633_ADC_H
#define __LINUX_MFD_PCF50633_ADC_H
#include <linux/mfd/pcf50633/core.h>
#include <linux/platform_device.h>
/* ADC Registers */
#define PCF50633_REG_ADCC3 0x52
#define PCF50633_REG_ADCC2 0x53
#define PCF50633_REG_ADCC1 0x54
#define PCF50633_REG_ADCS1 0x55
#define PCF50633_REG_ADCS2 0x56
#define PCF50633_REG_ADCS3 0x57
#define PCF50633_ADCC1_ADCSTART 0x01
#define PCF50633_ADCC1_RES_10BIT 0x02
#define PCF50633_ADCC1_AVERAGE_NO 0x00
#define PCF50633_ADCC1_AVERAGE_4 0x04
#define PCF50633_ADCC1_AVERAGE_8 0x08
#define PCF50633_ADCC1_AVERAGE_16 0x0c
#define PCF50633_ADCC1_MUX_BATSNS_RES 0x00
#define PCF50633_ADCC1_MUX_BATSNS_SUBTR 0x10
#define PCF50633_ADCC1_MUX_ADCIN2_RES 0x20
#define PCF50633_ADCC1_MUX_ADCIN2_SUBTR 0x30
#define PCF50633_ADCC1_MUX_BATTEMP 0x60
#define PCF50633_ADCC1_MUX_ADCIN1 0x70
#define PCF50633_ADCC1_AVERAGE_MASK 0x0c
#define PCF50633_ADCC1_ADCMUX_MASK 0xf0
#define PCF50633_ADCC2_RATIO_NONE 0x00
#define PCF50633_ADCC2_RATIO_BATTEMP 0x01
#define PCF50633_ADCC2_RATIO_ADCIN1 0x02
#define PCF50633_ADCC2_RATIO_BOTH 0x03
#define PCF50633_ADCC2_RATIOSETTL_100US 0x04
#define PCF50633_ADCC3_ACCSW_EN 0x01
#define PCF50633_ADCC3_NTCSW_EN 0x04
#define PCF50633_ADCC3_RES_DIV_TWO 0x10
#define PCF50633_ADCC3_RES_DIV_THREE 0x00
#define PCF50633_ADCS3_REF_NTCSW 0x00
#define PCF50633_ADCS3_REF_ACCSW 0x10
#define PCF50633_ADCS3_REF_2V0 0x20
#define PCF50633_ADCS3_REF_VISA 0x30
#define PCF50633_ADCS3_REF_2V0_2 0x70
#define PCF50633_ADCS3_ADCRDY 0x80
#define PCF50633_ADCS3_ADCDAT1L_MASK 0x03
#define PCF50633_ADCS3_ADCDAT2L_MASK 0x0c
#define PCF50633_ADCS3_ADCDAT2L_SHIFT 2
#define PCF50633_ASCS3_REF_MASK 0x70
extern int
pcf50633_adc_async_read(struct pcf50633 *pcf, int mux, int avg,
void (*callback)(struct pcf50633 *, void *, int),
void *callback_param);
extern int
pcf50633_adc_sync_read(struct pcf50633 *pcf, int mux, int avg);
#endif /* __LINUX_PCF50633_ADC_H */