drivers/spi: Adapt DW driver to new SPI API

Introducing as well a generic driver helper for CS gpio control and
buffer management.

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

Author: Tomasz Bursztyka

drivers/spi/Makefile

@@ -1,5 +1,9 @@
 obj-$(CONFIG_SPI_INTEL) += spi_intel.o
+ifeq ($(CONFIG_SPI_LEGACY_API),y)
+obj-$(CONFIG_SPI_DW) += spi_dw_legacy.o
+else
 obj-$(CONFIG_SPI_DW) += spi_dw.o
+endif
 obj-$(CONFIG_SPI_MCUX_DSPI) += spi_mcux_dspi.o
 obj-$(CONFIG_SPIM_NRF52) += spim_nrf52.o
 obj-$(CONFIG_SPIS_NRF5) += spis_nrf5.o

drivers/spi/spi_context.h

@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2017 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief Private API for SPI drivers
+ */
+
+#ifndef __SPI_DRIVER_COMMON_H__
+#define __SPI_DRIVER_COMMON_H__
+
+#include <gpio.h>
+#include <spi.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct spi_context {
+	struct spi_config *config;
+
+	const struct spi_buf **current_tx;
+	struct spi_buf **current_rx;
+
+	void *tx_buf;
+	u32_t tx_len;
+	void *rx_buf;
+	u32_t rx_len;
+};
+
+static inline bool spi_context_configured(struct spi_context *ctx,
+					  struct spi_config *config)
+{
+	return !!(ctx->config == config);
+}
+
+static inline void spi_context_cs_configure(struct spi_context *ctx)
+{
+	if (ctx->config->cs) {
+		gpio_pin_configure(ctx->config->cs->gpio_dev,
+				   ctx->config->cs->gpio_pin, GPIO_DIR_OUT);
+		gpio_pin_write(ctx->config->cs->gpio_dev,
+			       ctx->config->cs->gpio_pin, 1);
+	}
+}
+
+static inline void spi_context_cs_control(struct spi_context *ctx, bool on)
+{
+	if (ctx->config->cs) {
+		if (on) {
+			gpio_pin_write(ctx->config->cs->gpio_dev,
+				       ctx->config->cs->gpio_pin, 0);
+			k_busy_wait(ctx->config->cs->delay);
+		} else {
+			k_busy_wait(ctx->config->cs->delay);
+			gpio_pin_write(ctx->config->cs->gpio_dev,
+				       ctx->config->cs->gpio_pin, 1);
+		}
+	}
+}
+
+static inline void spi_context_buffers_setup(struct spi_context *ctx,
+					     const struct spi_buf **tx_bufs,
+					     struct spi_buf **rx_bufs,
+					     uint8_t dfs)
+{
+	SYS_LOG_DBG("tx_bufs %p (%p) - rx_bufs %p (%p) - %u",
+		    tx_bufs, tx_bufs ? *tx_bufs : NULL,
+		    rx_bufs, rx_bufs ? *rx_bufs : NULL, dfs);
+
+	ctx->current_tx = tx_bufs;
+	ctx->current_rx = rx_bufs;
+
+	if (*tx_bufs) {
+		ctx->tx_buf = (*tx_bufs)->buf;
+		ctx->tx_len = (*tx_bufs)->len/dfs;
+	} else {
+		ctx->tx_buf = NULL;
+		ctx->tx_len = 0;
+	}
+
+	if (*rx_bufs) {
+		ctx->rx_buf = (*rx_bufs)->buf;
+		ctx->rx_len = (*rx_bufs)->len/dfs;
+	} else {
+		ctx->rx_buf = NULL;
+		ctx->rx_len = 0;
+	}
+
+	SYS_LOG_DBG("current_tx %p, current_rx %p,"
+		    " tx buf/len %p/%u, rx buf/len %p/%u",
+		    ctx->current_tx, ctx->current_rx,
+		    ctx->tx_buf, ctx->tx_len, ctx->rx_buf, ctx->rx_len);
+}
+
+static ALWAYS_INLINE
+void spi_context_update_tx(struct spi_context *ctx, uint8_t dfs)
+{
+	if (!ctx->tx_len) {
+		return;
+	}
+
+	ctx->tx_len--;
+	if (!ctx->tx_len) {
+		ctx->current_tx++;
+		if (*ctx->current_tx) {
+			ctx->tx_buf = (*ctx->current_tx)->buf;
+			ctx->tx_len = (*ctx->current_tx)->len/dfs;
+		} else {
+			ctx->tx_buf = NULL;
+		}
+	} else if (ctx->tx_buf) {
+		ctx->tx_buf += dfs;
+	}
+
+	SYS_LOG_DBG("tx buf/len %p/%u", ctx->tx_buf, ctx->tx_len);
+}
+
+static ALWAYS_INLINE
+bool spi_context_tx_on(struct spi_context *ctx)
+{
+	return !!(ctx->tx_buf || ctx->tx_len);
+}
+
+static ALWAYS_INLINE
+void spi_context_update_rx(struct spi_context *ctx, uint8_t dfs)
+{
+	if (!ctx->rx_len) {
+		return;
+	}
+
+	ctx->rx_len--;
+	if (!ctx->rx_len) {
+		ctx->current_rx++;
+		if (*ctx->current_rx) {
+			ctx->rx_buf = (*ctx->current_rx)->buf;
+			ctx->rx_len = (*ctx->current_rx)->len/dfs;
+		} else {
+			ctx->rx_buf = NULL;
+		}
+	} else if (ctx->rx_buf) {
+		ctx->rx_buf += dfs;
+	}
+
+	SYS_LOG_DBG("rx buf/len %p/%u", ctx->rx_buf, ctx->rx_len);
+}
+
+static ALWAYS_INLINE
+bool spi_context_rx_on(struct spi_context *ctx)
+{
+	return !!(ctx->rx_buf || ctx->rx_len);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __SPI_DRIVER_COMMON_H__ */