Add support for PCA953x I2C gpio devices

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. The CONFIG_CMD_PCA953X_INFO
define enables an 'info' sub-command which provides summary
information for the given pca953x device.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>

1 files changed, 227 insertions, 0 deletions

diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
new file mode 100644
index 0000000..390d99a
--- /dev/null
+++ b/drivers/gpio/pca953x.c
@@ -0,0 +1,227 @@
+/*
+ * 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 <pca953x.h>
+
+/* Default to an address that hopefully won't corrupt other i2c devices */
+#ifndef CONFIG_SYS_I2C_PCA953X_ADDR
+#define CONFIG_SYS_I2C_PCA953X_ADDR	(~0)
+#endif
+
+enum {
+	PCA953X_CMD_INFO,
+	PCA953X_CMD_DEVICE,
+	PCA953X_CMD_OUTPUT,
+	PCA953X_CMD_INPUT,
+	PCA953X_CMD_INVERT,
+};
+
+/*
+ * 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
+#ifdef CONFIG_CMD_PCA953X_INFO
+/*
+ * 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");
+
+	if (i2c_read(chip, PCA953X_CONF, 1, &data, 1))
+		return -1;
+	printf("conf:      ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? 'i' : 'o');
+	printf("\n");
+
+	if (i2c_read(chip, PCA953X_POL, 1, &data, 1))
+		return -1;
+	printf("invert:    ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? '1' : '0');
+	printf("\n");
+
+	if (i2c_read(chip, PCA953X_IN, 1, &data, 1))
+		return -1;
+	printf("input:     ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? '1' : '0');
+	printf("\n");
+
+	if (i2c_read(chip, PCA953X_OUT, 1, &data, 1))
+		return -1;
+	printf("output:    ");
+	for (i = 7; i >= 0; i--)
+		printf("%c", data & (1 << i) ? '1' : '0');
+	printf("\n");
+
+	return 0;
+}
+#endif /* CONFIG_CMD_PCA953X_INFO */
+
+cmd_tbl_t cmd_pca953x[] = {
+	U_BOOT_CMD_MKENT(device, 3, 0, (void *)PCA953X_CMD_DEVICE, "", ""),
+	U_BOOT_CMD_MKENT(output, 4, 0, (void *)PCA953X_CMD_OUTPUT, "", ""),
+	U_BOOT_CMD_MKENT(input, 3, 0, (void *)PCA953X_CMD_INPUT, "", ""),
+	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)PCA953X_CMD_INVERT, "", ""),
+#ifdef CONFIG_CMD_PCA953X_INFO
+	U_BOOT_CMD_MKENT(info, 2, 0, (void *)PCA953X_CMD_INFO, "", ""),
+#endif
+};
+
+int do_pca953x(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	static uint8_t chip = CONFIG_SYS_I2C_PCA953X_ADDR;
+	int val;
+	ulong ul_arg2 = 0;
+	ulong ul_arg3 = 0;
+	cmd_tbl_t *c;
+
+	c = find_cmd_tbl(argv[1], cmd_pca953x, ARRAY_SIZE(cmd_pca953x));
+
+	/* All commands but "device" require 'maxargs' arguments */
+	if (!c || !((argc == (c->maxargs)) ||
+		(((int)c->cmd == PCA953X_CMD_DEVICE) &&
+		 (argc == (c->maxargs - 1))))) {
+		printf("Usage:\n%s\n", cmdtp->usage);
+		return 1;
+	}
+
+	/* arg2 used as chip number or pin number */
+	if (argc > 2)
+		ul_arg2 = simple_strtoul(argv[2], NULL, 16);
+
+	/* arg3 used as pin or invert value */
+	if (argc > 3)
+		ul_arg3 = simple_strtoul(argv[3], NULL, 16) & 0x1;
+
+	switch ((int)c->cmd) {
+#ifdef CONFIG_CMD_PCA953X_INFO
+	case PCA953X_CMD_INFO:
+		return pca953x_info(chip);
+#endif
+	case PCA953X_CMD_DEVICE:
+		if (argc == 3)
+			chip = (uint8_t)ul_arg2;
+		printf("Current device address: 0x%x\n", chip);
+		return 0;
+	case PCA953X_CMD_INPUT:
+		pca953x_set_dir(chip, (1 << ul_arg2),
+				PCA953X_DIR_IN << ul_arg2);
+		val = (pca953x_get_val(chip) & (1 << ul_arg2)) != 0;
+
+		printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2, val);
+		return val;
+	case PCA953X_CMD_OUTPUT:
+		pca953x_set_dir(chip, (1 << ul_arg2),
+				(PCA953X_DIR_OUT << ul_arg2));
+		return pca953x_set_val(chip, (1 << ul_arg2),
+					(ul_arg3 << ul_arg2));
+	case PCA953X_CMD_INVERT:
+		return pca953x_set_pol(chip, (1 << ul_arg2),
+					(ul_arg3 << ul_arg2));
+	default:
+		/* We should never get here */
+		return 1;
+	}
+}
+
+U_BOOT_CMD(
+	pca953x,	5,	1,	do_pca953x,
+	"pca953x	- pca953x gpio access\n",
+	"device [dev]\n"
+	"	- show or set current device address\n"
+#ifdef CONFIG_CMD_PCA953X_INFO
+	"pca953x info\n"
+	"	- display info for current chip\n"
+#endif
+	"pca953x output pin 0|1\n"
+	"	- set pin as output and drive low or high\n"
+	"pca953x invert pin 0|1\n"
+	"	- disable/enable polarity inversion for reads\n"
+	"pca953x intput pin\n"
+	"	- set pin as input and read value\n"
+);
+
+#endif /* CONFIG_CMD_PCA953X */