Add support for a Freescale non-CPM SPI controller

This patch adds support for the SPI controller found on Freescale PowerPC
processors such as the MCP834x family.  Additionally, a new config option,
CONFIG_HARD_SPI, is added for general purpose SPI controller use.

Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>

Makefile

@@ -230,6 +230,7 @@ LIBS += drivers/net/libnet.a
 LIBS += drivers/net/sk98lin/libsk98lin.a
 LIBS += drivers/pci/libpci.a
 LIBS += drivers/pcmcia/libpcmcia.a
+LIBS += drivers/spi/libspi.a
 ifeq ($(CPU),mpc83xx)
 LIBS += drivers/qe/qe.a
 endif
@@ -377,6 +378,7 @@ 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
 

README

@@ -1377,6 +1377,14 @@ The following options need to be configured:
 		SPI configuration items (port pins to use, etc). For
 		an example, see include/configs/sacsng.h.
 
+		CONFIG_HARD_SPI
+
+		Enables a hardware SPI driver for general-purpose reads
+		and writes.  As with CONFIG_SOFT_SPI, the board configuration
+		must define a list of chip-select function pointers.
+		Currently supported on some MPC8xxx processors.  For an
+		example, see include/configs/mpc8349emds.h.
+
 - FPGA Support: CONFIG_FPGA
 
 		Enables FPGA subsystem.

drivers/spi/Makefile

@@ -0,0 +1,46 @@
+#
+# (C) Copyright 2000-2007
+# Wolfgang Denk, DENX Software Engineering, wd@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-y += mpc8xxx_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
+
+#########################################################################

drivers/spi/mpc8xxx_spi.c

@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2006 Ben Warren, Qstreams Networks Inc.
+ * With help from the common/soft_spi and cpu/mpc8260 drivers
+ *
+ * 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/mpc8xxx_spi.h>
+
+#ifdef CONFIG_HARD_SPI
+
+#define SPI_EV_NE	0x80000000 >> 22	/* Receiver Not Empty */
+#define SPI_EV_NF	0x80000000 >> 23	/* Transmitter Not Full */
+
+#define SPI_MODE_LOOP	0x80000000 >> 1	/* Loopback mode */
+#define SPI_MODE_REV	0x80000000 >> 5	/* Reverse mode - MSB first */
+#define SPI_MODE_MS	0x80000000 >> 6	/* Always master */
+#define SPI_MODE_EN	0x80000000 >> 7	/* Enable interface */
+
+#define SPI_PRESCALER(reg, div) (reg)=((reg) & 0xfff0ffff) | ((div)<<16)
+#define SPI_CHARLENGTH(reg, div) (reg)=((reg) & 0xff0fffff) | ((div)<<20)
+
+#define SPI_TIMEOUT	1000
+
+void spi_init(void)
+{
+	volatile spi8xxx_t *spi = &((immap_t *) (CFG_IMMR))->spi;
+
+	/* ------------------------------------------------
+	 * SPI pins on the MPC83xx are not muxed, so all we do is initialize
+	 * some registers
+	 * ------------------------------------------------ */
+	spi->mode = SPI_MODE_REV | SPI_MODE_MS | SPI_MODE_EN;
+	SPI_PRESCALER(spi->mode, 1);	/* Use SYSCLK / 8  (16.67MHz typ.) */
+	spi->event = 0xffffffff;	/* Clear all SPI events */
+	spi->mask = 0x00000000;	/* Mask  all SPI interrupts */
+	spi->com = 0;		/* LST bit doesn't do anything, so disregard */
+}
+
+int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar * dout, uchar * din)
+{
+	volatile spi8xxx_t *spi = &((immap_t *) (CFG_IMMR))->spi;
+	unsigned int tmpdout, tmpdin, event;
+	int numBlks = bitlen / 32 + (bitlen % 32 ? 1 : 0);
+	int tm, isRead = 0;
+	unsigned char charSize = 32;
+
+	debug("spi_xfer: chipsel %08X dout %08X din %08X bitlen %d\n",
+	      (int)chipsel, *(uint *) dout, *(uint *) din, bitlen);
+
+	if (chipsel != NULL)
+		(*chipsel) (1);	/* select the target chip */
+
+	spi->event = 0xffffffff;	/* Clear all SPI events */
+
+	/* handle data in 32-bit chunks */
+	while (numBlks--) {
+		tmpdout = 0;
+		charSize = (bitlen >= 32 ? 32 : bitlen);
+
+		/* Shift data so it's msb-justified */
+		tmpdout = *(u32 *) dout >> (32 - charSize);
+
+		/* The LEN field of the SPMODE register is set as follows:
+		 *
+		 * Bit length           setting
+		 * l <= 4               3
+		 * 4 < l <= 16          l - 1
+		 * l > 16               0
+		 */
+
+		if (bitlen <= 16)
+			SPI_CHARLENGTH(spi->mode, bitlen <= 4 ? 3 : bitlen - 1);
+		else {
+			SPI_CHARLENGTH(spi->mode, 0);
+			/* Set up the next iteration if sending > 32 bits */
+			bitlen -= 32;
+			dout += 4;
+		}
+
+		spi->tx = tmpdout;	/* Write the data out */
+		debug("*** spi_xfer: ... %08x written\n", tmpdout);
+
+		/* --------------------------------
+		 * Wait for SPI transmit to get out
+		 * or time out (1 second = 1000 ms)
+		 * The NE event must be read and cleared first
+		 * -------------------------------- */
+		for (tm = 0, isRead = 0; tm < SPI_TIMEOUT; ++tm) {
+			event = spi->event;
+			if (event & SPI_EV_NE) {
+				tmpdin = spi->rx;
+				spi->event |= SPI_EV_NE;
+				isRead = 1;
+
+				*(u32 *) din = (tmpdin << (32 - charSize));
+				if (charSize == 32) {
+					/* Advance output buffer by 32 bits */
+					din += 4;
+				}
+			}
+			/* Only bail when we've had both NE and NF events.
+			 * This will cause timeouts on RO devices, so maybe
+			 * in the future put an arbitrary delay after writing
+			 * the device.  Arbitrary delays suck, though... */
+			if (isRead && (event & SPI_EV_NF))
+				break;
+		}
+		if (tm >= SPI_TIMEOUT)
+			puts("*** spi_xfer: Time out during SPI transfer");
+
+		debug("*** spi_xfer: transfer ended. Value=%08x\n", tmpdin);
+	}
+
+	if (chipsel != NULL)
+		(*chipsel) (0);	/* deselect the target chip */
+	return 0;
+}
+
+#endif				/* CONFIG_HARD_SPI */

include/asm-ppc/immap_83xx.h

@@ -30,6 +30,7 @@
 
 #include <asm/types.h>
 #include <asm/fsl_i2c.h>
+#include <asm/mpc8xxx_spi.h>
 
 /*
  * Local Access Window
@@ -627,7 +628,7 @@ typedef struct immap {
 	u8			res3[0x900];
 	lbus83xx_t		lbus;		/* Local Bus Controller Registers */
 	u8			res4[0x1000];
-	spi83xx_t		spi;		/* Serial Peripheral Interface */
+	spi8xxx_t		spi;		/* Serial Peripheral Interface */
 	dma83xx_t		dma;		/* DMA */
 	pciconf83xx_t		pci_conf[2];	/* PCI Software Configuration Registers */
 	ios83xx_t		ios;		/* Sequencer */
@@ -661,7 +662,7 @@ typedef struct immap {
 	u8			res2[0x900];
 	lbus83xx_t		lbus;		/* Local Bus Controller Registers */
 	u8			res3[0x1000];
-	spi83xx_t		spi;		/* Serial Peripheral Interface */
+	spi8xxx_t		spi;		/* Serial Peripheral Interface */
 	dma83xx_t		dma;		/* DMA */
 	pciconf83xx_t		pci_conf[1];	/* PCI Software Configuration Registers */
 	u8			res4[0x80];
@@ -696,7 +697,7 @@ typedef struct immap {
 	u8			res2[0x900];
 	lbus83xx_t		lbus;		/* Local Bus Controller Registers */
 	u8			res3[0x1000];
-	spi83xx_t		spi;		/* Serial Peripheral Interface */
+	spi8xxx_t		spi;		/* Serial Peripheral Interface */
 	dma83xx_t		dma;		/* DMA */
 	pciconf83xx_t		pci_conf[1];	/* PCI Software Configuration Registers */
 	u8			res4[0x80];
@@ -741,7 +742,7 @@ typedef struct immap {
 	u8			res2[0x900];
 	lbus83xx_t		lbus;		/* Local Bus Controller Registers */
 	u8			res3[0x1000];
-	spi83xx_t		spi;		/* Serial Peripheral Interface */
+	spi8xxx_t		spi;		/* Serial Peripheral Interface */
 	dma83xx_t		dma;		/* DMA */
 	pciconf83xx_t		pci_conf[1];	/* PCI Software Configuration Registers */
 	u8			res4[0x80];

include/asm-ppc/mpc8xxx_spi.h

@@ -0,0 +1,49 @@
+/*
+ * Freescale non-CPM SPI Controller
+ *
+ * Copyright 2008 Qstreams Networks, Inc.
+ *
+ * This software may be used and distributed according to the
+ * terms of the GNU Public License, Version 2, incorporated
+ * herein by reference.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * Version 2 as published by the Free Software Foundation.
+ *
+ * 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
+ */
+
+#ifndef _ASM_MPC8XXX_SPI_H_
+#define _ASM_MPC8XXX_SPI_H_
+
+#include <asm/types.h>
+
+#if defined(CONFIG_MPC834X) || \
+	defined(CONFIG_MPC8313) || \
+	defined(CONFIG_MPC8315) || \
+	defined(CONFIG_MPC837X)
+
+typedef struct spi8xxx
+{
+	u8 res0[0x20];	/* 0x0-0x01f reserved */
+	u32 mode;	/* mode register  */
+	u32 event;	/* event register */
+	u32 mask;	/* mask register  */
+	u32 com;	/* command register */
+	u32 tx;		/* transmit register */
+	u32 rx;		/* receive register */
+	u8 res1[0xC8];	/* fill up to 0x100 */
+} spi8xxx_t;
+
+#endif
+
+#endif	/* _ASM_MPC8XXX_SPI_H_ */

lib_ppc/board.c

@@ -87,6 +87,9 @@ void doc_init (void);
     defined(CONFIG_SOFT_I2C)
 #include <i2c.h>
 #endif
+#if defined(CONFIG_HARD_SPI)
+#include <spi.h>
+#endif
 #if defined(CONFIG_CMD_NAND)
 void nand_init (void);
 #endif
@@ -247,6 +250,16 @@ static int init_func_i2c (void)
 }
 #endif
 
+#if defined(CONFIG_HARD_SPI)
+static int init_func_spi (void)
+{
+	puts ("SPI:   ");
+	spi_init ();
+	puts ("ready\n");
+	return (0);
+}
+#endif
+
 /***********************************************************************/
 
 #if defined(CONFIG_WATCHDOG)
@@ -329,6 +342,9 @@ init_fnc_t *init_sequence[] = {
 #if defined(CONFIG_HARD_I2C) || defined(CONFIG_SOFT_I2C)
 	init_func_i2c,
 #endif
+#if defined(CONFIG_HARD_SPI)
+	init_func_spi,
+#endif
 #if defined(CONFIG_DTT)		/* Digital Thermometers and Thermostats */
 	dtt_init,
 #endif