common: change interface to SPI flash

Allow more than one SPI master.
Add CONFIG variables to address the system SPI flash.

To have SPI master ports, spi_ports array must be defined.

BRANCH=smaug
TEST=compile
BUG=chrome-os-partner:42304

Change-Id: Id43869f648965c1582b7be1c7fb3a38f175fda95
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/288512
Commit-Queue: David James <davidjames@chromium.org>

1 files changed, 50 insertions, 7 deletions

diff --git a/include/spi.h b/include/spi.h
index d62c1420ca..21629ddd4d 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -27,26 +27,69 @@ enum spi_clock_mode {
 	SPI_CLOCK_MODE3 = 3
 };
 
-/* Enable / disable the SPI port.  When the port is disabled, all its I/O lines
- * are high-Z so the EC won't interfere with other devices on the SPI bus. */
-int spi_enable(int enable);
+struct spi_device_t {
+	/*
+	 * SPI port the device is connected to.
+	 * On some architecture, this is SPI master port index,
+	 * on other the SPI port index directly.
+	 */
+	uint8_t port;
+
+	/*
+	 * Clock divisor to talk to SPI device.
+	 * If several devices share the same port, we select the lowest speed.
+	 */
+	uint8_t div;
+
+	/* gpio used for chip selection. */
+	enum gpio_signal gpio_cs;
+};
+
+extern const struct spi_device_t spi_devices[];
+extern const unsigned int spi_devices_used;
+
+/*
+ * The first port in spi_ports define the port to access the SPI flash.
+ * The first gpio defines the CS GPIO to access the flash,
+ * if used.
+ */
+#define SPI_FLASH_DEVICE (&spi_devices[0])
+
+/*
+ * Enable / disable the SPI port.  When the port is disabled, all its I/O lines
+ * are high-Z so the EC won't interfere with other devices on the SPI bus.
+ *
+ * @param port  port id to work on.
+ * @param enable  1 to enable the port, 0 to disable it.
+ */
+int spi_enable(int port, int enable);
 
 /* Issue a SPI transaction.  Assumes SPI port has already been enabled.
+ *
  * Transmits <txlen> bytes from <txdata>, throwing away the corresponding
  * received data, then transmits <rxlen> dummy bytes, saving the received data
- * in <rxdata>. */
-int spi_transaction(const uint8_t *txdata, int txlen,
+ * in <rxdata>.
+ *
+ * @param spi_device  the SPI device to use
+ * @param txdata  buffer to transmit
+ * @param txlen  number of bytes in txdata.
+ * @param rxdata  receive buffer.
+ * @param rxlen  number of bytes in rxdata.
+ */
+int spi_transaction(const struct spi_device_t *spi_device,
+		    const uint8_t *txdata, int txlen,
 		    uint8_t *rxdata, int rxlen);
 
 /* Similar to spi_transaction(), but hands over to DMA for reading response.
  * Must call spi_transaction_flush() after this to make sure the response is
  * received.
  */
-int spi_transaction_async(const uint8_t *txdata, int txlen,
+int spi_transaction_async(const struct spi_device_t *spi_device,
+			  const uint8_t *txdata, int txlen,
 			  uint8_t *rxdata, int rxlen);
 
 /* Wait for async response received */
-int spi_transaction_flush(void);
+int spi_transaction_flush(const struct spi_device_t *spi_device);
 
 #ifdef CONFIG_SPI
 /**