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#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;
};
static void adc_read_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 of 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)
{
int head, tail;
mutex_lock(&pcf->adc.queue_mutex);
head = pcf->adc.queue_head;
tail = pcf->adc.queue_tail;
if (!pcf->adc.queue[head])
goto out;
adc_read_setup(pcf, pcf->adc.queue[head]->mux,
pcf->adc.queue[head]->avg);
out:
mutex_unlock(&pcf->adc.queue_mutex);
}
static int
adc_enqueue_request(struct pcf50633 *pcf, struct pcf50633_adc_request *req)
{
int head, tail;
mutex_lock(&pcf->adc.queue_mutex);
head = pcf->adc.queue_head;
tail = pcf->adc.queue_tail;
if (pcf->adc.queue[tail]) {
mutex_unlock(&pcf->adc.queue_mutex);
return -EBUSY;
}
pcf->adc.queue[tail] = req;
pcf->adc.queue_tail =
(tail + 1) & (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
mutex_unlock(&pcf->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;
/*We know here that the passed param is an adc_request object */
req = (struct pcf50633_adc_request *)param;
req->result = result;
complete(&req->completion);
}
int pcf50633_adc_sync_read(struct pcf50633 *pcf, int mux, int avg)
{
struct pcf50633_adc_request *req;
int result;
/* req is freed when the result is ready, in pcf50633_work*/
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);
result = req->result;
return result;
}
EXPORT_SYMBOL(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 pcf50633_work*/
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(pcf50633_adc_async_read);
static int adc_result(struct pcf50633 *pcf)
{
u16 ret = (pcf50633_reg_read(pcf, PCF50633_REG_ADCS1) << 2) |
(pcf50633_reg_read(pcf, PCF50633_REG_ADCS3) &
PCF50633_ADCS3_ADCDAT1L_MASK);
dev_info(pcf->dev, "adc result = %d\n", ret);
return ret;
}
static void pcf50633_adc_irq(struct pcf50633 *pcf, int irq, void *unused)
{
struct pcf50633_adc_request *req;
int head;
mutex_lock(&pcf->adc.queue_mutex);
head = pcf->adc.queue_head;
req = pcf->adc.queue[head];
if (!req) {
dev_err(pcf->dev, "ADC queue empty\n");
mutex_unlock(&pcf->adc.queue_mutex);
return;
}
pcf->adc.queue[head] = NULL;
pcf->adc.queue_head = (head + 1) &
(PCF50633_MAX_ADC_FIFO_DEPTH - 1);
mutex_unlock(&pcf->adc.queue_mutex);
req->callback(pcf, req->callback_param, adc_result(pcf));
kfree(req);
trigger_next_adc_job_if_any(pcf);
}
int __init pcf50633_adc_probe(struct platform_device *pdev)
{
struct pcf50633 *pcf;
pcf = platform_get_drvdata(pdev);
/* Set up IRQ handlers */
pcf->irq_handler[PCF50633_IRQ_ADCRDY].handler = pcf50633_adc_irq;
mutex_init(&pcf->adc.queue_mutex);
return 0;
}
static int __devexit pcf50633_adc_remove(struct platform_device *pdev)
{
struct pcf50633 *pcf;
pcf = platform_get_drvdata(pdev);
pcf->irq_handler[PCF50633_IRQ_ADCRDY].handler = NULL;
return 0;
}
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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