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>

diff --git a/arch/arm/plat-s3c/include/plat/adc.h b/arch/arm/plat-s3c/include/plat/adc.h
index d847bd476b6c29ffab98369250dc63b09a43025f..5f3b1cd53b908d406fac6cb2d83c71d73e78d03d 100644 (file)
--- a/arch/arm/plat-s3c/include/plat/adc.h
+++ b/arch/arm/plat-s3c/include/plat/adc.h
@@ -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);
 

diff --git a/arch/arm/plat-s3c24xx/adc.c b/arch/arm/plat-s3c24xx/adc.c
index ee1baf11ad9e9851754a3514d1c6eb359f7de4ca..11117a7ba911e735f911b6ba5dea75d8bf3d2f66 100644 (file)
--- a/arch/arm/plat-s3c24xx/adc.c
+++ b/arch/arm/plat-s3c24xx/adc.c
@@ -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);