[U-Boot] [PATCH v2 1/3] Add support for PCA953x I2C gpio devices

Peter Tyser ptyser at xes-inc.com
Mon Oct 27 19:59:13 CET 2008


Initial support for NXP's 4 and 8 bit I2C gpio expanders
(eg pca9537, pca9557, etc). The CONFIG_PCA953X define
enables support for the devices while the CONFIG_CMD_PCA953X
define enables the pca953x command.

Signed-off-by: Peter Tyser <ptyser at xes-inc.com>
---
 Makefile               |    2 +
 README                 |    7 ++
 drivers/gpio/Makefile  |   47 ++++++++++++
 drivers/gpio/pca953x.c |  186 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/gpio/pca953x.h |   39 ++++++++++
 5 files changed, 281 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpio/Makefile
 create mode 100644 drivers/gpio/pca953x.c
 create mode 100644 include/gpio/pca953x.h

diff --git a/Makefile b/Makefile
index fceb8a2..40c08a7 100644
--- a/Makefile
+++ b/Makefile
@@ -221,6 +221,7 @@ LIBS += disk/libdisk.a
 LIBS += drivers/bios_emulator/libatibiosemu.a
 LIBS += drivers/block/libblock.a
 LIBS += drivers/dma/libdma.a
+LIBS += drivers/gpio/libgpio.a
 LIBS += drivers/hwmon/libhwmon.a
 LIBS += drivers/i2c/libi2c.a
 LIBS += drivers/input/libinput.a
@@ -396,6 +397,7 @@ TAG_SUBDIRS += disk
 TAG_SUBDIRS += common
 TAG_SUBDIRS += drivers/bios_emulator
 TAG_SUBDIRS += drivers/block
+TAG_SUBDIRS += drivers/gpio
 TAG_SUBDIRS += drivers/hwmon
 TAG_SUBDIRS += drivers/i2c
 TAG_SUBDIRS += drivers/input
diff --git a/README b/README
index ebee20f..73bed41 100644
--- a/README
+++ b/README
@@ -601,6 +601,7 @@ The following options need to be configured:
 		CONFIG_CMD_MII		* MII utility commands
 		CONFIG_CMD_NAND		* NAND support
 		CONFIG_CMD_NET		  bootp, tftpboot, rarpboot
+		CONFIG_CMD_PCA953X	* PCA953x I2C gpio commands
 		CONFIG_CMD_PCI		* pciinfo
 		CONFIG_CMD_PCMCIA		* PCMCIA support
 		CONFIG_CMD_PING		* send ICMP ECHO_REQUEST to network
@@ -678,6 +679,12 @@ The following options need to be configured:
 		Note that if the RTC uses I2C, then the I2C interface
 		must also be configured. See I2C Support, below.
 
+- GPIO Support:
+		CONFIG_PCA953X		- use NXP's PCA953X series I2C GPIO
+
+		Note that if the GPIO device uses I2C, then the I2C interface
+		must also be configured. See I2C Support, below.
+
 - Timestamp Support:
 
 		When CONFIG_TIMESTAMP is selected, the timestamp
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
new file mode 100644
index 0000000..dd618ed
--- /dev/null
+++ b/drivers/gpio/Makefile
@@ -0,0 +1,47 @@
+#
+# Copyright 2000-2008
+# 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 	:= $(obj)libgpio.a
+
+COBJS-$(CONFIG_PCA953X)	+= pca953x.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/gpio/pca953x.c b/drivers/gpio/pca953x.c
new file mode 100644
index 0000000..317241a
--- /dev/null
+++ b/drivers/gpio/pca953x.c
@@ -0,0 +1,186 @@
+/*
+ * Copyright 2008 Extreme Engineering Solutions, Inc.
+ *
+ * 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
+ */
+
+/*
+ * Driver for NXP's 4 and 8 bit I2C gpio expanders (eg pca9537, pca9557, etc)
+ * TODO: support additional devices with more than 8-bits GPIO
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <gpio/pca953x.h>
+
+/*
+ * Modify masked bits in register
+ */
+static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
+{
+	uint8_t val;
+
+	if (i2c_read(chip, addr, 1, &val, 1))
+		return -1;
+
+	val &= ~mask;
+	val |= data;
+
+	return i2c_write(chip, addr, 1, &val, 1);
+}
+
+/*
+ * Set output value of IO pins in 'mask' to corresponding value in 'data'
+ * 0 = low, 1 = high
+ */
+int pca953x_set_val(uint8_t chip, uint mask, uint data)
+{
+	return pca953x_reg_write(chip, PCA953X_OUT, mask, data);
+}
+
+/*
+ * Set read polarity of IO pins in 'mask' to corresponding value in 'data'
+ * 0 = read pin value, 1 = read inverted pin value
+ */
+int pca953x_set_pol(uint8_t chip, uint mask, uint data)
+{
+	return pca953x_reg_write(chip, PCA953X_POL, mask, data);
+}
+
+/*
+ * Set direction of IO pins in 'mask' to corresponding value in 'data'
+ * 0 = output, 1 = input
+ */
+int pca953x_set_dir(uint8_t chip, uint mask, uint data)
+{
+	return pca953x_reg_write(chip, PCA953X_CONF, mask, data);
+}
+
+/*
+ * Read current logic level of all IO pins
+ */
+int pca953x_get_val(uint8_t chip)
+{
+	uint8_t val;
+
+	if (i2c_read(chip, 0, 1, &val, 1))
+		return -1;
+
+	return (int)val;
+}
+
+#ifdef CONFIG_CMD_PCA953X
+/*
+ * Display pca953x information
+ */
+static int pca953x_info(uint8_t chip)
+{
+	int i;
+	uint8_t data;
+
+	printf("pca953x@ 0x%x:\n\n", chip);
+	printf("gpio pins: 76543210\n");
+	printf("-------------------\n");
+
+	i2c_read(chip, PCA953X_CONF, 1, &data, 1);
+	printf("conf:      ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? 'i' : 'o');
+	printf("\n");
+
+	i2c_read(chip, PCA953X_POL, 1, &data, 1);
+	printf("invert:    ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? '1' : '0');
+	printf("\n");
+
+	i2c_read(chip, PCA953X_IN, 1, &data, 1);
+	printf("input:     ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? '1' : '0');
+	printf("\n");
+
+	i2c_read(chip, PCA953X_OUT, 1, &data, 1);
+	printf("output:    ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? '1' : '0');
+	printf("\n");
+
+	return 0;
+}
+
+int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	int val;
+	uint8_t chip;
+	ulong pin;
+
+	chip = (uint8_t)simple_strtoul(argv[1], NULL, 16);
+
+	if (i2c_probe(chip)) {
+		printf("I2C device 0x%02x not found\n", chip);
+		return -1;
+	}
+
+	switch (argc) {
+	case 3:
+		if (strcmp(argv[2], "info") == 0)
+			return pca953x_info(chip);
+		break;
+	case 4:
+		if (strcmp(argv[2], "input") != 0)
+			break;
+
+		pin = simple_strtoul(argv[3], NULL, 16);
+
+		pca953x_set_dir(chip, (1 << pin), PCA953X_DIR_IN << pin);
+		val = (pca953x_get_val(chip) & (1 << pin)) != 0;
+
+		printf("chip 0x%02x, pin 0x%lx = %d\n", chip, pin, val);
+		return val;
+	case 5:
+		pin = simple_strtoul(argv[3], NULL, 16);
+		val = simple_strtoul(argv[4], NULL, 16) & 0x1;
+
+		if (strcmp(argv[2], "output") == 0) {
+			pca953x_set_dir(chip, (1 << pin),
+					(PCA953X_DIR_OUT << pin));
+			return pca953x_set_val(chip, (1 << pin), (val << pin));
+		} else if (strcmp(argv[2], "invert") == 0) {
+			return pca953x_set_pol(chip, (1 << pin), (val << pin));
+		}
+		break;
+	default:
+		break;
+	}
+
+	printf("Usage:\n%s\n", cmdtp->usage);
+	return 1;
+}
+
+U_BOOT_CMD(
+	pca953x,	6,	2,	do_pca953x,
+	"pca953x	- pca953x gpio access\n",
+	"chip info\n"
+	"	- display info for chip\n"
+	"pca953x chip output pin 0|1\n"
+	"	- set pin as output and drive low or high\n"
+	"pca953x chip invert pin 0|1\n"
+	"	- disable/enable polarity inversion for reads\n"
+	"pca953x chip intput pin\n"
+	"	- set pin as input and read value\n"
+);
+
+#endif /* CONFIG_CMD_PCA953X */
diff --git a/include/gpio/pca953x.h b/include/gpio/pca953x.h
new file mode 100644
index 0000000..6c2b58c
--- /dev/null
+++ b/include/gpio/pca953x.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright 2008 Extreme Engineering Solutions, Inc.
+ *
+ * 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 __PCA953X_H_
+#define __PCA953X_H_
+
+#define PCA953X_IN		0x00
+#define PCA953X_OUT		0x01
+#define PCA953X_POL		0x02
+#define PCA953X_CONF		0x03
+
+#define PCA953X_OUT_LOW		0
+#define PCA953X_OUT_HIGH	1
+#define PCA953X_POL_NORMAL	0
+#define PCA953X_POL_INVERT	1
+#define PCA953X_DIR_OUT		0
+#define PCA953X_DIR_IN		1
+
+int pca953x_set_val(u8 chip, uint mask, uint data);
+int pca953x_set_pol(u8 chip, uint mask, uint data);
+int pca953x_set_dir(u8 chip, uint mask, uint data);
+int pca953x_get_val(u8 chip);
+
+#endif /* __PCA953X_H_ */
-- 
1.6.0.2.GIT



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