drivers/spi: Handle ressource locking and release in DW driver

Again this is made as generic as possible through driver's
spi_context API.

Signed-off-by: Tomasz Bursztyka <[email protected]>

Author: Tomasz Bursztyka

drivers/spi/spi_context.h

@@ -64,6 +64,10 @@ static inline void spi_context_lock(struct spi_context *ctx,
 
 static inline void spi_context_release(struct spi_context *ctx, int status)
 {
+	if (!status && (ctx->config->operation & SPI_LOCK_ON)) {
+		return;
+	}
+
 #ifdef CONFIG_POLL
 	if (!ctx->asynchronous || status) {
 		k_sem_give(&ctx->lock);
@@ -73,6 +77,13 @@ static inline void spi_context_release(struct spi_context *ctx, int status)
 #endif
 }
 
+static inline void spi_context_unlock_unconditionally(struct spi_context *ctx)
+{
+	if (!k_sem_count_get(&ctx->lock)) {
+		k_sem_give(&ctx->lock);
+	}
+}
+
 static inline void spi_context_wait_for_completion(struct spi_context *ctx)
 {
 #ifdef CONFIG_POLL
@@ -94,7 +105,9 @@ static inline void spi_context_complete(struct spi_context *ctx, int status)
 			k_poll_signal(ctx->signal, status);
 		}
 
-		k_sem_give(&ctx->lock);
+		if (!(ctx->config->operation & SPI_LOCK_ON)) {
+			k_sem_give(&ctx->lock);
+		}
 	}
 #else
 	k_sem_give(&ctx->sync);

drivers/spi/spi_dw.c

@@ -339,6 +339,16 @@ static int spi_dw_transceive_async(struct spi_config *config,
 
 static int spi_dw_release(struct spi_config *config)
 {
+	const struct spi_dw_config *info = config->dev->config->config_info;
+	struct spi_dw_data *spi = config->dev->driver_data;
+
+	if (!spi_context_configured(&spi->ctx, config) ||
+	    test_bit_ssienr(info->regs) || test_bit_sr_busy(info->regs)) {
+		return -EBUSY;
+	}
+
+	spi_context_unlock_unconditionally(&spi->ctx);
+
 	return 0;
 }