[U-Boot-Users] [RFC 2/2] atmel_spi: Driver for the Atmel SPI controller
Haavard Skinnemoen
hskinnemoen at atmel.com
Fri Nov 30 13:44:15 CET 2007
From: Hans-Christian Egtvedt <hcegtvedt at atmel.com>
This adds a driver for the SPI controller found on most AT91 and AVR32
chips.
Currently, AT91RM9200 seems to have a SPI framework on its own. It
probably makes sense to merge the two drivers and make AT91RM9200 use
the framework everyone else uses at some point...
[hskinnemoen at atmel.com: moved to drivers/spi and simplified]
Signed-off-by: Haavard Skinnemoen <hskinnemoen at atmel.com>
---
Makefile | 2 +
drivers/spi/Makefile | 46 +++++++++++++++++++
drivers/spi/atmel_spi.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/spi/atmel_spi.h | 84 +++++++++++++++++++++++++++++++++++
4 files changed, 243 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/Makefile
create mode 100644 drivers/spi/atmel_spi.c
create mode 100644 drivers/spi/atmel_spi.h
diff --git a/Makefile b/Makefile
index bfd4132..7293a11 100644
--- a/Makefile
+++ b/Makefile
@@ -227,6 +227,7 @@ LIBS += drivers/qe/qe.a
endif
LIBS += drivers/rtc/librtc.a
LIBS += drivers/serial/libserial.a
+LIBS += drivers/spi/libspi.a
LIBS += drivers/usb/libusb.a
LIBS += drivers/video/libvideo.a
LIBS += post/libpost.a post/drivers/libpostdrivers.a
@@ -359,6 +360,7 @@ TAG_SUBDIRS += drivers/pcmcia
TAG_SUBDIRS += drivers/qe
TAG_SUBDIRS += drivers/rtc
TAG_SUBDIRS += drivers/serial
+TAG_SUBDIRS += drivers/spi
TAG_SUBDIRS += drivers/usb
TAG_SUBDIRS += drivers/video
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
new file mode 100644
index 0000000..61d33a1
--- /dev/null
+++ b/drivers/spi/Makefile
@@ -0,0 +1,46 @@
+#
+# (C) Copyright 2000-2007
+# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB := $(obj)libspi.a
+
+COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
+
+COBJS := $(COBJS-y)
+SRCS := $(COBJS:.o=.c)
+OBJS := $(addprefix $(obj),$(COBJS))
+
+all: $(LIB)
+
+$(LIB): $(obj).depend $(OBJS)
+ $(AR) $(ARFLAGS) $@ $(OBJS)
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
new file mode 100644
index 0000000..11b2a59
--- /dev/null
+++ b/drivers/spi/atmel_spi.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2007 Atmel Corporation
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <common.h>
+#include <spi.h>
+
+#include <asm/io.h>
+
+#include <asm/arch/clk.h>
+#include <asm/arch/memory-map.h>
+
+#define ATMEL_SPI_MASTER 0
+#define ATMEL_SPI_BASE SPI0_BASE
+
+#include "atmel_spi.h"
+
+void spi_init()
+{
+ /* We currently don't support external chip select decoding */
+ spi_writel(CR, ATMEL_SPI_CR_SWRST);
+ spi_writel(CR, ATMEL_SPI_CR_SPIEN);
+ spi_writel(MR, ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_PCS(15));
+}
+
+int spi_setup(int cs, unsigned int max_hz, unsigned int mode)
+{
+ unsigned long scbr;
+ u32 csrx;
+
+ if (cs >= 4 || !spi_cs_is_valid(cs))
+ return -1;
+
+ scbr = (get_spi_clk_rate(ATMEL_SPI_MASTER) + max_hz - 1) / max_hz;
+ if (scbr > ATMEL_SPI_CSRx_SCBR_MAX)
+ /* Too low max SCK rate */
+ return -1;
+ if (scbr < 1)
+ scbr = 1;
+
+ csrx = ATMEL_SPI_CSRx_SCBR(scbr);
+ csrx |= ATMEL_SPI_CSRx_BITS(ATMEL_SPI_BITS_8);
+ if (!(mode & SPI_CPHA))
+ csrx |= ATMEL_SPI_CSRx_NCPHA;
+ if (mode & SPI_CPOL)
+ csrx |= ATMEL_SPI_CSRx_CPOL;
+
+ spi_writel(CSR(cs), csrx);
+
+ return 0;
+}
+
+int spi_xfer(int cs, int bitlen, uchar *dout, uchar *din)
+{
+ unsigned int len_tx;
+ unsigned int len_rx;
+ unsigned int len;
+ u32 status;
+
+ if (bitlen == 0)
+ return 0;
+ if (bitlen < 0 || bitlen % 8)
+ return -1;
+
+ len = bitlen / 8;
+
+ spi_writel(MR, ATMEL_SPI_MR_MSTR | ATMEL_SPI_MR_PCS(~(1 << cs)));
+
+ for (len_tx = 0, len_rx = 0; len_rx < len; ) {
+ status = spi_readl(SR);
+
+ if (status & (ATMEL_SPI_SR_MODF | ATMEL_SPI_SR_OVRES))
+ return -1;
+
+ if (len_tx < len && (status & ATMEL_SPI_SR_TDRE)) {
+ spi_writel(TDR, *dout++);
+ len_tx++;
+ }
+ if (status & ATMEL_SPI_SR_RDRF) {
+ *din++ = spi_readl(RDR);
+ len_rx++;
+ }
+ }
+
+ /*
+ * Wait until the transfer is completely done so that we can
+ * be sure that CS is deactivated.
+ */
+ do {
+ status = spi_readl(SR);
+ } while (!(status & ATMEL_SPI_SR_TXEMPTY));
+
+ return 0;
+}
diff --git a/drivers/spi/atmel_spi.h b/drivers/spi/atmel_spi.h
new file mode 100644
index 0000000..4df8cbe
--- /dev/null
+++ b/drivers/spi/atmel_spi.h
@@ -0,0 +1,84 @@
+/*
+ * Register definitions for the Atmel AT32/AT91 SPI Controller
+ */
+
+/* Register offsets */
+#define ATMEL_SPI_CR 0x0000
+#define ATMEL_SPI_MR 0x0004
+#define ATMEL_SPI_RDR 0x0008
+#define ATMEL_SPI_TDR 0x000c
+#define ATMEL_SPI_SR 0x0010
+#define ATMEL_SPI_IER 0x0014
+#define ATMEL_SPI_IDR 0x0018
+#define ATMEL_SPI_IMR 0x001c
+#define ATMEL_SPI_CSR(x) (0x0030 + 4 * (x))
+#define ATMEL_SPI_VERSION 0x00fc
+
+/* Bits in CR */
+#define ATMEL_SPI_CR_SPIEN (1 << 0)
+#define ATMEL_SPI_CR_SPIDIS (1 << 1)
+#define ATMEL_SPI_CR_SWRST (1 << 7)
+#define ATMEL_SPI_CR_LASTXFER (1 << 24)
+
+/* Bits in MR */
+#define ATMEL_SPI_MR_MSTR (1 << 0)
+#define ATMEL_SPI_MR_PS (1 << 1)
+#define ATMEL_SPI_MR_PCSDEC (1 << 2)
+#define ATMEL_SPI_MR_FDIV (1 << 3)
+#define ATMEL_SPI_MR_MODFDIS (1 << 4)
+#define ATMEL_SPI_MR_LLB (1 << 7)
+#define ATMEL_SPI_MR_PCS(x) (((x) & 15) << 16)
+#define ATMEL_SPI_MR_DLYBCS(x) ((x) << 24)
+
+/* Bits in RDR */
+#define ATMEL_SPI_RDR_RD(x) (x)
+#define ATMEL_SPI_RDR_PCS(x) ((x) << 16)
+
+/* Bits in TDR */
+#define ATMEL_SPI_TDR_TD(x) (x)
+#define ATMEL_SPI_TDR_PCS(x) ((x) << 16)
+#define ATMEL_SPI_TDR_LASTXFER (1 << 24)
+
+/* Bits in SR/IER/IDR/IMR */
+#define ATMEL_SPI_SR_RDRF (1 << 0)
+#define ATMEL_SPI_SR_TDRE (1 << 1)
+#define ATMEL_SPI_SR_MODF (1 << 2)
+#define ATMEL_SPI_SR_OVRES (1 << 3)
+#define ATMEL_SPI_SR_ENDRX (1 << 4)
+#define ATMEL_SPI_SR_ENDTX (1 << 5)
+#define ATMEL_SPI_SR_RXBUFF (1 << 6)
+#define ATMEL_SPI_SR_TXBUFE (1 << 7)
+#define ATMEL_SPI_SR_NSSR (1 << 8)
+#define ATMEL_SPI_SR_TXEMPTY (1 << 9)
+#define ATMEL_SPI_SR_SPIENS (1 << 16)
+
+/* Bits in CSRx */
+#define ATMEL_SPI_CSRx_CPOL (1 << 0)
+#define ATMEL_SPI_CSRx_NCPHA (1 << 1)
+#define ATMEL_SPI_CSRx_CSAAT (1 << 3)
+#define ATMEL_SPI_CSRx_BITS(x) ((x) << 4)
+#define ATMEL_SPI_CSRx_SCBR(x) ((x) << 8)
+#define ATMEL_SPI_CSRx_SCBR_MAX 0xff
+#define ATMEL_SPI_CSRx_DLYBS(x) ((x) << 16)
+#define ATMEL_SPI_CSRx_DLYBCT(x) ((x) << 24)
+
+/* Bits in VERSION */
+#define ATMEL_SPI_VERSION_REV(x) ((x) << 0)
+#define ATMEL_SPI_VERSION_MFN(x) ((x) << 16)
+
+/* Constants for CSRx:BITS */
+#define ATMEL_SPI_BITS_8 0
+#define ATMEL_SPI_BITS_9 1
+#define ATMEL_SPI_BITS_10 2
+#define ATMEL_SPI_BITS_11 3
+#define ATMEL_SPI_BITS_12 4
+#define ATMEL_SPI_BITS_13 5
+#define ATMEL_SPI_BITS_14 6
+#define ATMEL_SPI_BITS_15 7
+#define ATMEL_SPI_BITS_16 8
+
+/* Register access macros */
+#define spi_readl(reg) \
+ readl((void *)ATMEL_SPI_BASE + ATMEL_SPI_##reg)
+#define spi_writel(reg, value) \
+ writel(value, (void *)ATMEL_SPI_BASE + ATMEL_SPI_##reg)
--
1.5.3.4
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