update todos

ads1278_core.c

@@ -2,7 +2,6 @@
 #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)
@@ -12,15 +11,14 @@
 // 10'000'000 Hz =  52 kSPS
 #define TRANSFER_HZ	(27000000)
 
-// TODO: minimize 45us delay between xfers
-
-// 24-11-23: We're hitting 130 kSPS initially, but are eventually slowed down
-// to 87 kSPS. Need to investigate high-priority workers, forcing a high SPI
-// clock speed, and/or minimizing overall latency.
+// TODO:
+// - Require max CPU clock speed so 130 kSPS can be achieved
+// - Minimize ~30us delay between transfers
+// - Figure out how to get sample data out
+// - Create configuration interface
 
 struct ads1278
 {
-	struct workqueue_struct *wq;
 	unsigned char *rx;
 	unsigned char *tx;
 	dma_addr_t rx_dma_handle;
@@ -31,43 +29,26 @@ struct ads1278
 	int running[2];
 };
 
-static struct spi_device *spip = NULL;
-static void ads1278_work_handler(struct work_struct *w)
-{
-	struct ads1278 *ads;
-
-	if (!spip)
-		return;
-
-        ads = spi_get_drvdata(spip);
-
-	while (!ads->stop_requested) {
-		spi_sync_locked(spip, &ads->msg[0]);
-	}
-}
-static DECLARE_WORK(ads1278_work, ads1278_work_handler);
-
 static void ads1278_transfer_callback1(void *context)
 {
-//	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;
+	struct spi_device *spi = (struct spi_device *)context;
+        struct ads1278 *ads = spi_get_drvdata(spi);
+
+	if (!ads->stop_requested)
+		spi_async(spi, &ads->msg[0]);
+	else
+		ads->running[0] = 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;
+	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;
 }
 
 
@@ -138,16 +119,8 @@ 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]);
-
-	ads->wq = create_singlethread_workqueue("ads1278");
-	if (ads->wq) {
-		spip = spi;
-		queue_work(ads->wq, &ads1278_work);
-	}
-
-	return 0;
+	/* TODO ret = */ spi_async(spi, &ads->msg[0]);
+	return spi_async(spi, &ads->msg[1]);
 }
 
 static int ads1278_probe(struct spi_device *spi)
@@ -176,7 +149,6 @@ 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;
@@ -212,14 +184,9 @@ 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.");
 }