svn commit: r238955 - head/sys/arm/at91

[Warner Losh]

Author: imp
Date: Tue Jul 31 19:14:22 2012
New Revision: 238955
URL: http://svn.freebsd.org/changeset/base/238955

Log:
  Allow chip selects other than 0.  The SAM9260EK board
  has its dataflash on CS1.

Modified:
  head/sys/arm/at91/at91_spi.c

Modified: head/sys/arm/at91/at91_spi.c
==============================================================================
--- head/sys/arm/at91/at91_spi.c	Tue Jul 31 18:47:17 2012	(r238954)
+++ head/sys/arm/at91/at91_spi.c	Tue Jul 31 19:14:22 2012	(r238955)
@@ -42,6 +42,7 @@ __FBSDID("$FreeBSD$");
 
 #include <machine/bus.h>
 
+#include <arm/at91/at91var.h>
 #include <arm/at91/at91_spireg.h>
 #include <arm/at91/at91_pdcreg.h>
 
@@ -144,6 +145,7 @@ at91_spi_attach(device_t dev)
 	 * memory and APB bandwidth.
 	 * Also, currently we lack a way for lettting both the board and the
 	 * slave devices take their maximum supported SPI clocks into account.
+	 * Also, we hard-wire SPI mode to 3.
 	 */
 	csr = SPI_CSR_CPOL | (4 << 16) | (0xff << 8);
 	WR4(sc, SPI_CSR0, csr);
@@ -285,7 +287,10 @@ at91_spi_transfer(device_t dev, device_t
 	 */
 	WR4(sc, PDC_PTCR, PDC_PTCR_TXTDIS | PDC_PTCR_RXTDIS);
 
-#ifdef SPI_CHIPSEL_SUPPORT
+	/*
+	 * PSCDEC = 0 has a range of 0..3 for chip select.  We
+	 * don't support PSCDEC = 1 which has a range of 0..15.
+	 */
 	if (cmd->cs < 0 || cmd->cs > 3) {
 		device_printf(dev,
 		    "Invalid chip select %d requested by %s\n", cmd->cs,
@@ -293,18 +298,23 @@ at91_spi_transfer(device_t dev, device_t
 		err = EINVAL;
 		goto out;
 	}
+
 #ifdef SPI_CHIP_SELECT_HIGH_SUPPORT
+	/*
+	 * The AT91RM9200 couldn't do CS high for CS 0.  Other chips can, but we
+	 * don't support that yet, or other spi modes.
+	 */
 	if (at91_is_rm92() && cmd->cs == 0 &&
 	    (cmd->flags & SPI_CHIP_SELECT_HIGH) != 0) {
 		device_printf(dev,
-		    "Invalid chip select high requested by %s\n",
+		    "Invalid chip select high requested by %s for cs 0.\n",
 		    device_get_nameunit(child));
 		err = EINVAL;
 		goto out;
 	}
 #endif
-	WR4(sc, SPI_MR, (RD4(sc, SPI_MR) & ~0x000f0000) | CS_TO_MR(cmd->cs));
-#endif
+	err = (RD4(sc, SPI_MR) & ~0x000f0000) | CS_TO_MR(cmd->cs);
+	WR4(sc, SPI_MR, err);
 
 	/*
 	 * Set up the TX side of the transfer.