Add support for multi-device SPI bus.

sancus-tee · Sep 7, 2017 · e5e1a34 · e5e1a34
1 parent e80ef7d
commit e5e1a34
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Showing 3 changed files with 12 additions and 14 deletions.
diff --git a/.gitignore b/.gitignore
@@ -1,3 +1,4 @@
 build*/
 *~
 *.kdev*
+*.swp
diff --git a/include/sancus_support/spi.h b/include/sancus_support/spi.h
@@ -16,8 +16,8 @@ typedef enum
 } SpiCpha;
 
 void spi_init(SpiCpol cpol, SpiCpha cpha, unsigned int clk_div);
-void spi_select(void);
-void spi_deselect(void);
+void spi_select(int dev);
+#define spi_deselect() spi_select(0x0)
 
 uint8_t spi_write_read_byte(uint8_t data);
 void spi_write_byte(uint8_t data);

diff --git a/src/dev/spi.c b/src/dev/spi.c
@@ -4,12 +4,13 @@
 #define SPI_CNTRL  *(volatile uint8_t*)0x0151
 #define SPI_STATUS *(volatile uint8_t*)0x0152
 
-#define SPI_CPOL    0
-#define SPI_CPHA    1
-#define SPI_SELECT  2
-#define SPI_CLK_DIV 3
+#define SPI_CPOL            0
+#define SPI_CPHA            1
+#define SPI_SELECT          2
+#define SPI_CLK_DIV         4
+#define SPI_SELECT_WIDTH    (SPI_CLK_DIV - SPI_SELECT)
 
-#define SPI_BUSY 0x01
+#define SPI_BUSY            0x01
 
 void spi_init(SpiCpol cpol, SpiCpha cpha, unsigned int clk_div)
 {
@@ -18,14 +19,10 @@ void spi_init(SpiCpol cpol, SpiCpha cpha, unsigned int clk_div)
                 (clk_div << SPI_CLK_DIV);
 }
 
-void spi_select()
+void spi_select(int dev)
 {
-    SPI_CNTRL |= (1 << SPI_SELECT);
-}
-
-void spi_deselect()
-{
-    SPI_CNTRL &= ~(1 << SPI_SELECT);
+    dev &= ((1 << SPI_SELECT_WIDTH) - 1);
+    SPI_CNTRL |= (dev << SPI_SELECT);
 }
 
 uint8_t spi_write_read_byte(uint8_t data)
-Original file line number
+Diff line change
@@ -1,3 +1,4 @@
     build*/
     *~
     *.kdev*
+    *.swp