Module Name:    src
Committed By:   thorpej
Date:           Fri Apr 30 02:24:06 UTC 2021

Modified Files:
        src/sys/arch/shark/conf: GENERIC files.shark
Added Files:
        src/sys/arch/shark/shark: shark_iic.c

Log Message:
Driver for the I2C bus used for RAM serial presence detection.  This
I2C interface is implemented by bit-banging a couple of GPIO pins on
the Sequoia core logic used in the Shark.

Heavy lifting by Julian Coleman, and minor tweaks and a different
autoconfiguration scheme by me.


To generate a diff of this commit:
cvs rdiff -u -r1.139 -r1.140 src/sys/arch/shark/conf/GENERIC
cvs rdiff -u -r1.23 -r1.24 src/sys/arch/shark/conf/files.shark
cvs rdiff -u -r0 -r1.1 src/sys/arch/shark/shark/shark_iic.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

Modified files:

Index: src/sys/arch/shark/conf/GENERIC
diff -u src/sys/arch/shark/conf/GENERIC:1.139 src/sys/arch/shark/conf/GENERIC:1.140
--- src/sys/arch/shark/conf/GENERIC:1.139	Fri Apr 30 02:11:37 2021
+++ src/sys/arch/shark/conf/GENERIC	Fri Apr 30 02:24:05 2021
@@ -1,4 +1,4 @@
-#	$NetBSD: GENERIC,v 1.139 2021/04/30 02:11:37 thorpej Exp $
+#	$NetBSD: GENERIC,v 1.140 2021/04/30 02:24:05 thorpej Exp $
 #
 # Generic Shark configuration.
 #
@@ -7,7 +7,7 @@ include	"arch/shark/conf/std.shark"
 
 options 	INCLUDE_CONFIG_FILE	# embed config file in kernel binary
 
-#ident		"GENERIC-$Revision: 1.139 $"
+#ident		"GENERIC-$Revision: 1.140 $"
 
 # estimated number of users
 maxusers	32
@@ -211,6 +211,14 @@ ofisa*		at ofbus?
 sequoia*	at ofbus?
 ofisa*		at sequoia?
 
+# Shark I2C interface
+sharkiic*	at sequoia?
+iic*		at sharkiic?
+
+# Only 2 DIMM slots in a Shark.
+spdmem*        at iic? addr 0x50
+spdmem*        at iic? addr 0x51
+
 # IDE/ATA disk
 wdc*		at ofisa?
 atabus* 	at wdc? channel ?

Index: src/sys/arch/shark/conf/files.shark
diff -u src/sys/arch/shark/conf/files.shark:1.23 src/sys/arch/shark/conf/files.shark:1.24
--- src/sys/arch/shark/conf/files.shark:1.23	Fri Apr 30 02:11:37 2021
+++ src/sys/arch/shark/conf/files.shark	Fri Apr 30 02:24:05 2021
@@ -1,4 +1,4 @@
-#	$NetBSD: files.shark,v 1.23 2021/04/30 02:11:37 thorpej Exp $
+#	$NetBSD: files.shark,v 1.24 2021/04/30 02:24:05 thorpej Exp $
 #
 # First try for arm-specific configuration info
 #
@@ -60,6 +60,11 @@ file	arch/shark/ofw/wdc_ofisa_machdep.c	
 device	sequoia { }: ofisa_subclass
 attach	sequoia at ofbus
 
+# Shark I2C (for DRAM SPD)
+device	sharkiic: i2cbus
+attach	sharkiic at sequoia
+file	arch/shark/shark/shark_iic.c		sharkiic
+
 # Glue for OFW ISA device attachment
 device	ofisascr {}
 attach	ofisascr at ofisa

Added files:

Index: src/sys/arch/shark/shark/shark_iic.c
diff -u /dev/null src/sys/arch/shark/shark/shark_iic.c:1.1
--- /dev/null	Fri Apr 30 02:24:06 2021
+++ src/sys/arch/shark/shark/shark_iic.c	Fri Apr 30 02:24:05 2021
@@ -0,0 +1,291 @@
+/*	$NetBSD: shark_iic.c,v 1.1 2021/04/30 02:24:05 thorpej Exp $	*/
+
+/*
+ * Copyright (c) 2021 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Julian Coleman.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+
+__KERNEL_RCSID(0, "$NetBSD: shark_iic.c,v 1.1 2021/04/30 02:24:05 thorpej Exp $");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+
+#include <dev/ofw/openfirm.h>
+
+#include <shark/shark/sequoia.h>
+
+#include <dev/i2c/i2cvar.h>
+#include <dev/i2c/i2c_bitbang.h>
+
+#include <arm/cpufunc.h>
+
+/* define registers on sequoia used by pins  */
+#define	SEQUOIA_1GPIO		PMC_GPCR_REG		/* reg 0x007 gpio 0-3 */
+#define	SEQUOIA_2GPIO		SEQ2_OGPIOCR_REG	/* reg 0x304 gpio 4.8 */
+
+/* define pins on sequoia that talk to the DIMM I2C bus */
+#define	IIC_CLK			FOMPCR_M_PCON9
+#define	IIC_DATA_IN_DIR		GPCR_M_GPIODIR3
+#define	IIC_DATA_IN		GPCR_M_GPIODATA3
+#define	IIC_DATA_OUT_DIR	GPIOCR2_M_GPIOBDIR1
+
+/* logical i2c signals */
+#define	SHARK_IIC_BIT_SDA	0x01
+#define	SHARK_IIC_BIT_SCL	0x02
+#define	SHARK_IIC_BIT_OUTPUT	0x04
+#define	SHARK_IIC_BIT_INPUT	0x08
+
+struct sharkiic_softc {
+	device_t		sc_dev;
+	struct i2c_controller	sc_i2c;
+};
+
+/* I2C bitbanging */
+
+static void
+sequoiaBBInit(void)
+{
+	uint16_t	seqReg;
+
+	sequoiaLock();
+
+	/*
+	 * SCL initialization
+	 * - enable pc[9]
+	 * - set pin to low (0)
+	 */
+	sequoiaRead(SEQR_SEQPSR3_REG, &seqReg);
+	CLR(seqReg, SEQPSR3_M_PC9PINEN);
+	sequoiaWrite(SEQR_SEQPSR3_REG, seqReg);
+	sequoiaRead(PMC_FOMPCR_REG, &seqReg);
+	SET(seqReg, IIC_CLK);
+	sequoiaWrite(PMC_FOMPCR_REG, seqReg);
+
+	/*
+	 * SDA (Output) initialization
+	 * - set direction to output
+	 * - enable GPIO B1 (sets pin to low)
+	 */
+	sequoiaRead(PMC_GPIOCR2_REG, &seqReg);
+	SET(seqReg, IIC_DATA_OUT_DIR);
+	sequoiaWrite(PMC_GPIOCR2_REG, seqReg);
+	sequoiaRead(SEQR_SEQPSR2_REG, &seqReg);
+	SET(seqReg, SEQPSR2_M_GPIOB1PINEN);
+	sequoiaWrite(SEQR_SEQPSR2_REG, seqReg);
+
+	/*
+	 * SDA (Input) initialization
+	 * - enable GPIO
+	 * - set direction to input
+	 */
+	sequoiaRead(SEQ2_SEQ2PSR_REG, &seqReg);
+	CLR(seqReg, SEQ2PSR_M_GPIOPINEN);
+	sequoiaWrite(SEQ2_SEQ2PSR_REG, seqReg);
+	sequoiaRead(SEQUOIA_1GPIO, &seqReg);
+	CLR(seqReg, IIC_DATA_IN_DIR);
+	sequoiaWrite(SEQUOIA_1GPIO, seqReg);
+
+	sequoiaUnlock();
+}
+
+static void
+sequoiaBBSetBits(uint32_t bits)
+{
+	uint16_t	seqRegSDA, seqRegSCL;
+
+	sequoiaLock();
+
+	sequoiaRead(PMC_FOMPCR_REG, &seqRegSCL);
+	sequoiaRead(SEQR_SEQPSR2_REG, &seqRegSDA);
+
+	/*
+	 * For SCL and SDA:
+	 * - output is the inverse of the desired signal
+	 * - the pin enable bit drives the signal
+	 */
+	if (bits & SHARK_IIC_BIT_SCL) {
+		CLR(seqRegSCL, IIC_CLK);
+	} else {
+		SET(seqRegSCL, IIC_CLK);
+	}
+
+	if (bits & SHARK_IIC_BIT_SDA) {
+		CLR(seqRegSDA, SEQPSR2_M_GPIOB1PINEN);
+	} else {
+		SET(seqRegSDA, SEQPSR2_M_GPIOB1PINEN);
+	}
+
+	sequoiaWrite(PMC_FOMPCR_REG, seqRegSCL);
+	sequoiaWrite(SEQR_SEQPSR2_REG, seqRegSDA);
+
+	sequoiaUnlock();
+}
+
+static void
+sequoiaBBSetDir(uint32_t dir)
+{
+	uint16_t	seqReg;
+
+	sequoiaLock();
+
+	/*
+	 * For direction = Input, set SDA (Output) direction to input,
+	 * otherwise we'll only read our own signal on SDA (Input)
+	 */
+	sequoiaRead(PMC_GPIOCR2_REG, &seqReg);
+	if (dir & SHARK_IIC_BIT_OUTPUT)
+		SET(seqReg, IIC_DATA_OUT_DIR);
+	else
+		CLR(seqReg, IIC_DATA_OUT_DIR);
+	sequoiaWrite(PMC_GPIOCR2_REG, seqReg);
+
+	sequoiaUnlock();
+}
+
+static uint32_t
+sequoiaBBRead(void)
+{
+	uint16_t	seqRegSDA, seqRegSCL;
+	uint32_t	bits = 0;
+
+	sequoiaLock();
+
+	sequoiaRead(SEQUOIA_1GPIO, &seqRegSDA);
+	sequoiaRead(PMC_FOMPCR_REG, &seqRegSCL);
+
+	sequoiaUnlock();
+
+	if (ISSET(seqRegSDA, IIC_DATA_IN))
+		bits |= SHARK_IIC_BIT_SDA;
+	if (!ISSET(seqRegSCL, IIC_CLK))
+		bits |= SHARK_IIC_BIT_SCL;
+
+	return bits;
+}
+
+static void
+sharkiicbb_set_bits(void *cookie, uint32_t bits)
+{
+	sequoiaBBSetBits(bits);
+}
+
+static void
+sharkiicbb_set_dir(void *cookie, uint32_t dir)
+{
+	sequoiaBBSetDir(dir);
+}
+
+static uint32_t
+sharkiicbb_read(void *cookie)
+{
+	return sequoiaBBRead();
+}
+
+static const struct i2c_bitbang_ops sharkiicbb_ops = {
+	.ibo_set_bits	=	sharkiicbb_set_bits,
+	.ibo_set_dir	=	sharkiicbb_set_dir,
+	.ibo_read_bits	=	sharkiicbb_read,
+	.ibo_bits = {
+		[I2C_BIT_SDA]		=	SHARK_IIC_BIT_SDA,
+		[I2C_BIT_SCL]		=	SHARK_IIC_BIT_SCL,
+		[I2C_BIT_OUTPUT]	=	SHARK_IIC_BIT_OUTPUT,
+		[I2C_BIT_INPUT]		=	SHARK_IIC_BIT_INPUT,
+	},
+};
+
+/* higher level I2C stuff */
+
+static int
+sharkiic_send_start(void *cookie, int flags)
+{
+	return (i2c_bitbang_send_start(cookie, flags, &sharkiicbb_ops));
+}
+
+static int
+sharkiic_send_stop(void *cookie, int flags)
+{
+	return (i2c_bitbang_send_stop(cookie, flags, &sharkiicbb_ops));
+}
+
+static int
+sharkiic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
+{
+	return (i2c_bitbang_initiate_xfer(cookie, addr, flags, 
+	    &sharkiicbb_ops));
+}
+
+static int
+sharkiic_read_byte(void *cookie, uint8_t *valp, int flags)
+{
+	return (i2c_bitbang_read_byte(cookie, valp, flags, &sharkiicbb_ops));
+}
+
+static int
+sharkiic_write_byte(void *cookie, uint8_t val, int flags)
+{
+	return (i2c_bitbang_write_byte(cookie, val, flags, &sharkiicbb_ops));
+}
+
+static int
+sharkiic_match(device_t parent, cfdata_t match, void *aux)
+{
+	struct ofbus_attach_args *oba = aux;
+
+	/* "sequoia" interface fills out oba_ofname */
+	return strcmp(oba->oba_ofname, "dec,dnard-i2c") == 0;
+}
+
+static void
+sharkiic_attach(device_t parent, device_t self, void *aux)
+{
+	struct sharkiic_softc *sc = device_private(self);
+	struct i2cbus_attach_args iba;
+
+	aprint_naive("\n");
+	aprint_normal("\n");
+
+	sequoiaBBInit();
+
+	iic_tag_init(&sc->sc_i2c);
+	sc->sc_i2c.ic_cookie = sc;
+	sc->sc_i2c.ic_send_start = sharkiic_send_start;
+	sc->sc_i2c.ic_send_stop = sharkiic_send_stop;
+	sc->sc_i2c.ic_initiate_xfer = sharkiic_initiate_xfer;
+	sc->sc_i2c.ic_read_byte = sharkiic_read_byte;
+	sc->sc_i2c.ic_write_byte = sharkiic_write_byte;
+
+	memset(&iba, 0, sizeof(iba));
+	iba.iba_tag = &sc->sc_i2c;
+
+	config_found(self, &iba, iicbus_print, CFARG_EOL);
+}
+
+CFATTACH_DECL_NEW(sharkiic, sizeof(struct sharkiic_softc),
+    sharkiic_match, sharkiic_attach, NULL, NULL);

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