try workqueue for efficiency

diff --git a/ads1278_core.c b/ads1278_core.c
index e47f0c7f9d7c616bbb9cff084c9ae0d1d62feb22..c09c62a9e7c8534e0221efe1346a71d85ee56bbb 100644 (file)
--- a/ads1278_core.c
+++ b/ads1278_core.c
@@ -2,6 +2,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/workqueue.h>
 #include <linux/spi/spi.h>
 
 #define FRAME_SIZE     (24)
@@ -19,6 +20,7 @@
 
 struct ads1278
 {
+       struct workqueue_struct *wq;
        unsigned char *rx;
        unsigned char *tx;
        dma_addr_t rx_dma_handle;
@@ -29,26 +31,43 @@ struct ads1278
        int running[2];
 };
 
-static void ads1278_transfer_callback1(void *context)
+static struct spi_device *spip = NULL;
+static void ads1278_work_handler(struct work_struct *w)
 {
-       struct spi_device *spi = (struct spi_device *)context;
-        struct ads1278 *ads = spi_get_drvdata(spi);
+       struct ads1278 *ads;
+
+       if (!spip)
+               return;
+
+        ads = spi_get_drvdata(spip);
 
-       if (!ads->stop_requested)
-               spi_async(spi, &ads->msg[0]);
-       else
-               ads->running[0] = 0;
+       while (!ads->stop_requested) {
+               spi_sync_locked(spip, &ads->msg[0]);
+       }
 }
+static DECLARE_WORK(ads1278_work, ads1278_work_handler);
 
-static void ads1278_transfer_callback2(void *context)
+static void ads1278_transfer_callback1(void *context)
 {
-       struct spi_device *spi = (struct spi_device *)context;
-        struct ads1278 *ads = spi_get_drvdata(spi);
+//     struct spi_device *spi = (struct spi_device *)context;
+//        struct ads1278 *ads = spi_get_drvdata(spi);
+//
+//     if (!ads->stop_requested)
+//             queue_work(ads->wq, &ads1278_work);
+//             //spi_async(spi, &ads->msg[0]);
+//     else
+//             ads->running[0] = 0;
+}
 
-       if (!ads->stop_requested)
-               spi_async(spi, &ads->msg[1]);
-       else
-               ads->running[1] = 0;
+static void ads1278_transfer_callback2(void *context)
+{
+//     struct spi_device *spi = (struct spi_device *)context;
+//        struct ads1278 *ads = spi_get_drvdata(spi);
+//
+//     if (!ads->stop_requested)
+//             spi_async(spi, &ads->msg[1]);
+//     else
+//             ads->running[1] = 0;
 }
 
 
@@ -119,8 +138,16 @@ static int ads1278_begin_transfer(struct spi_device *spi)
        ads->running[0] = 1;
        ads->running[1] = 1;
 
-       /* TODO ret = */ spi_async(spi, &ads->msg[0]);
-       return spi_async(spi, &ads->msg[1]);
+//     /* TODO ret = */ spi_async(spi, &ads->msg[0]);
+//     return spi_async(spi, &ads->msg[1]);
+
+       ads->wq = create_singlethread_workqueue("ads1278");
+       if (ads->wq) {
+               spip = spi;
+               queue_work(ads->wq, &ads1278_work);
+       }
+
+       return 0;
 }
 
 static int ads1278_probe(struct spi_device *spi)
@@ -149,6 +176,7 @@ static int ads1278_probe(struct spi_device *spi)
 
        dev_info(&spi->dev, "ready to go!");
 
+       spi_bus_lock(spi->controller);
        if (ads1278_begin_transfer(spi)) {
                dev_err(&spi->dev, "error with initial transfer!");
                goto end_free_ads;
@@ -184,9 +212,14 @@ static void ads1278_remove(struct spi_device *spi)
                dma_free_coherent(&spi->dev, TRANSFER_SIZE * 2, ads->tx, ads->tx_dma_handle);
                dma_free_coherent(&spi->dev, TRANSFER_SIZE * 2, ads->rx, ads->rx_dma_handle);
 
+               flush_scheduled_work();
+               if (ads->wq)
+                       destroy_workqueue(ads->wq);
+
                kfree(ads);
        }
 
+       spi_bus_unlock(spi->controller);
        dev_info(&spi->dev, "done.");
 }