ARM: S3C: Add ADC synchronous read call.

To add HWMON support, we need a synchronous read() call that blocks
until completion. Add the client that is being service to the select
and convert callbacks to make the code easier.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Ben Dooks 2009-07-18 10:12:27 +01:00 committed by Ben Dooks
parent 885f9ebe75
commit e170adcb40
2 changed files with 59 additions and 13 deletions

View File

@ -19,10 +19,14 @@ struct s3c_adc_client;
extern int s3c_adc_start(struct s3c_adc_client *client,
unsigned int channel, unsigned int nr_samples);
extern int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch);
extern struct s3c_adc_client *
s3c_adc_register(struct platform_device *pdev,
void (*select)(unsigned selected),
void (*conv)(unsigned d0, unsigned d1,
void (*select)(struct s3c_adc_client *client,
unsigned selected),
void (*conv)(struct s3c_adc_client *client,
unsigned d0, unsigned d1,
unsigned *samples_left),
unsigned int is_ts);

View File

@ -39,13 +39,16 @@
struct s3c_adc_client {
struct platform_device *pdev;
struct list_head pend;
wait_queue_head_t *wait;
unsigned int nr_samples;
int result;
unsigned char is_ts;
unsigned char channel;
void (*select_cb)(unsigned selected);
void (*convert_cb)(unsigned val1, unsigned val2,
void (*select_cb)(struct s3c_adc_client *c, unsigned selected);
void (*convert_cb)(struct s3c_adc_client *c,
unsigned val1, unsigned val2,
unsigned *samples_left);
};
@ -81,7 +84,7 @@ static inline void s3c_adc_select(struct adc_device *adc,
{
unsigned con = readl(adc->regs + S3C2410_ADCCON);
client->select_cb(1);
client->select_cb(client, 1);
con &= ~S3C2410_ADCCON_MUXMASK;
con &= ~S3C2410_ADCCON_STDBM;
@ -153,25 +156,61 @@ int s3c_adc_start(struct s3c_adc_client *client,
}
EXPORT_SYMBOL_GPL(s3c_adc_start);
static void s3c_adc_default_select(unsigned select)
static void s3c_convert_done(struct s3c_adc_client *client,
unsigned v, unsigned u, unsigned *left)
{
client->result = v;
wake_up(client->wait);
}
int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch)
{
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);
int ret;
client->convert_cb = s3c_convert_done;
client->wait = &wake;
client->result = -1;
ret = s3c_adc_start(client, ch, 1);
if (ret < 0)
goto err;
ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);
if (client->result < 0) {
ret = -ETIMEDOUT;
goto err;
}
client->convert_cb = NULL;
return client->result;
err:
return ret;
}
EXPORT_SYMBOL_GPL(s3c_adc_convert);
static void s3c_adc_default_select(struct s3c_adc_client *client,
unsigned select)
{
}
struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
void (*select)(unsigned int selected),
void (*conv)(unsigned d0, unsigned d1,
void (*select)(struct s3c_adc_client *client,
unsigned int selected),
void (*conv)(struct s3c_adc_client *client,
unsigned d0, unsigned d1,
unsigned *samples_left),
unsigned int is_ts)
{
struct s3c_adc_client *client;
WARN_ON(!pdev);
WARN_ON(!conv);
if (!select)
select = s3c_adc_default_select;
if (!conv || !pdev)
if (!pdev)
return ERR_PTR(-EINVAL);
client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);
@ -230,16 +269,19 @@ static irqreturn_t s3c_adc_irq(int irq, void *pw)
adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);
client->nr_samples--;
(client->convert_cb)(data0 & 0x3ff, data1 & 0x3ff, &client->nr_samples);
if (client->convert_cb)
(client->convert_cb)(client, data0 & 0x3ff, data1 & 0x3ff,
&client->nr_samples);
if (client->nr_samples > 0) {
/* fire another conversion for this */
client->select_cb(1);
client->select_cb(client, 1);
s3c_adc_convert(adc);
} else {
local_irq_save(flags);
(client->select_cb)(0);
(client->select_cb)(client, 0);
adc->cur = NULL;
s3c_adc_try(adc);