Patchwork [U-Boot,1/2] gpio: tca642x: Add the tca642x gpio expander driver

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Submitter Dan Murphy
Date July 8, 2013, 8:53 p.m.
Message ID <1373316840-28436-1-git-send-email-dmurphy@ti.com>
Download mbox | patch
Permalink /patch/257602/
State Superseded
Delegated to: Tom Rini
Headers show

Comments

Dan Murphy - July 8, 2013, 8:53 p.m.
Add the tca642x gpio expander driver

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---
 drivers/gpio/Makefile  |    1 +
 drivers/gpio/tca642x.c |  312 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/tca642x.h      |   64 ++++++++++
 3 files changed, 377 insertions(+)
 create mode 100644 drivers/gpio/tca642x.c
 create mode 100644 include/tca642x.h
Nishanth Menon - July 8, 2013, 9:27 p.m.
On 07/08/2013 03:53 PM, Dan Murphy wrote:
> Add the tca642x gpio expander driver
http://www.ti.com/sitesearch/docs/universalsearch.tsp?searchTerm=tca642&linkId=1
I think there are just TCA6424 ?
giving a link to the product helps I suppose.
>
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
>   drivers/gpio/Makefile  |    1 +
>   drivers/gpio/tca642x.c |  312 ++++++++++++++++++++++++++++++++++++++++++++++++
>   include/tca642x.h      |   64 ++++++++++
>   3 files changed, 377 insertions(+)
>   create mode 100644 drivers/gpio/tca642x.c
>   create mode 100644 include/tca642x.h
>
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index f77c1ec..7e74dfe 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -49,6 +49,7 @@ COBJS-$(CONFIG_BCM2835_GPIO)	+= bcm2835_gpio.o
>   COBJS-$(CONFIG_S3C2440_GPIO)	+= s3c2440_gpio.o
>   COBJS-$(CONFIG_XILINX_GPIO)	+= xilinx_gpio.o
>   COBJS-$(CONFIG_ADI_GPIO2)	+= adi_gpio2.o
> +COBJS-$(CONFIG_TCA642X)		+= tca642x.o
>
>   COBJS	:= $(COBJS-y)
>   SRCS 	:= $(COBJS:.o=.c)
> diff --git a/drivers/gpio/tca642x.c b/drivers/gpio/tca642x.c
> new file mode 100644
> index 0000000..740714d
> --- /dev/null
> +++ b/drivers/gpio/tca642x.c
> @@ -0,0 +1,312 @@
> +/*
> + * Copyright 2013 Texas Instruments, Inc.
> + *
> + * Derived work from the pca953x.c driver
> + *
> + * 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
> + */
> +
> +#include <common.h>
> +#include <i2c.h>
> +#include <tca642x.h>
> +
> +/* tca642x register address definitions */
> +struct tca642x_bank_info tca642x_banks[] = {
> +	{0x00, 0x04, 0x08, 0x0c},
> +	{0x01, 0x05, 0x09, 0x0d},
> +	{0x02, 0x06, 0x0a, 0x0e},
could we use explicit map of the struct params? helps any future expansion.

> +};
> +
> +/*
> + * Modify masked bits in register
> + */
> +static int tca642x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
> +{
> +	uint16_t valw;
why not use u8 instead? same for mask and data?
> +	int org_bus_num;
> +	int ret;
> +
> +	org_bus_num = i2c_get_bus_num();
> +	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
> +
> +	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
> +		printf("Could not read before writing\n");
> +		ret = -1;
> +		goto error;
> +	}
> +	valw &= ~mask;
data &= mask ?
> +	valw |= data;
> +
> +	ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
> +
> +error:
> +	i2c_set_bus_num(org_bus_num);
> +	return ret;
> +
extra eol?
> +}
> +
> +static int tca642x_reg_read(uint8_t chip, uint addr, uint *data)
same here? addr is u8, data is u8 *?
> +{
> +	uint16_t valw;
val as u8?
> +	int org_bus_num;
> +	int ret = 0;
> +
> +	org_bus_num = i2c_get_bus_num();
> +	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
> +	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
> +		ret = -1;
> +		goto error;
> +	}
> +
> +	*data = (int)valw;
> +
> +error:
> +	i2c_set_bus_num(org_bus_num);
> +	return ret;
> +}
[...]
Dan Murphy - July 9, 2013, 4:17 p.m.
Nishanth
Thanks for the feedback

On 07/08/2013 04:27 PM, Nishanth Menon wrote:
> On 07/08/2013 03:53 PM, Dan Murphy wrote:
>> Add the tca642x gpio expander driver
> http://www.ti.com/sitesearch/docs/universalsearch.tsp?searchTerm=tca642&linkId=1 
>
> I think there are just TCA6424 ?
> giving a link to the product helps I suppose.
Done.  Next patchset
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>>   drivers/gpio/Makefile  |    1 +
>>   drivers/gpio/tca642x.c |  312 
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>   include/tca642x.h      |   64 ++++++++++
>>   3 files changed, 377 insertions(+)
>>   create mode 100644 drivers/gpio/tca642x.c
>>   create mode 100644 include/tca642x.h
>>
>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>> index f77c1ec..7e74dfe 100644
>> --- a/drivers/gpio/Makefile
>> +++ b/drivers/gpio/Makefile
>> @@ -49,6 +49,7 @@ COBJS-$(CONFIG_BCM2835_GPIO)    += bcm2835_gpio.o
>>   COBJS-$(CONFIG_S3C2440_GPIO)    += s3c2440_gpio.o
>>   COBJS-$(CONFIG_XILINX_GPIO)    += xilinx_gpio.o
>>   COBJS-$(CONFIG_ADI_GPIO2)    += adi_gpio2.o
>> +COBJS-$(CONFIG_TCA642X)        += tca642x.o
>>
>>   COBJS    := $(COBJS-y)
>>   SRCS     := $(COBJS:.o=.c)
>> diff --git a/drivers/gpio/tca642x.c b/drivers/gpio/tca642x.c
>> new file mode 100644
>> index 0000000..740714d
>> --- /dev/null
>> +++ b/drivers/gpio/tca642x.c
>> @@ -0,0 +1,312 @@
>> +/*
>> + * Copyright 2013 Texas Instruments, Inc.
>> + *
>> + * Derived work from the pca953x.c driver
>> + *
>> + * 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
>> + */
>> +
>> +#include <common.h>
>> +#include <i2c.h>
>> +#include <tca642x.h>
>> +
>> +/* tca642x register address definitions */
>> +struct tca642x_bank_info tca642x_banks[] = {
>> +    {0x00, 0x04, 0x08, 0x0c},
>> +    {0x01, 0x05, 0x09, 0x0d},
>> +    {0x02, 0x06, 0x0a, 0x0e},
> could we use explicit map of the struct params? helps any future 
> expansion.
>
Not sure what you are looking for here.  These are the register 
addresses within the chip.
>> +};
>> +
>> +/*
>> + * Modify masked bits in register
>> + */
>> +static int tca642x_reg_write(uint8_t chip, uint addr, uint mask, 
>> uint data)
>> +{
>> +    uint16_t valw;
> why not use u8 instead? same for mask and data?
Doh.  That was carried over from the derivation work. Done.  Next patchset
>> +    int org_bus_num;
>> +    int ret;
>> +
>> +    org_bus_num = i2c_get_bus_num();
>> +    i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
>> +
>> +    if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
>> +        printf("Could not read before writing\n");
>> +        ret = -1;
>> +        goto error;
>> +    }
>> +    valw &= ~mask;
> data &= mask ?
Well in this case the mask is not being passed in.  The bit to flip is 
being passed and then the actual mask
is created here.

This code should be fine unless others object as well.
>> +    valw |= data;
>> +
>> +    ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
>> +
>> +error:
>> +    i2c_set_bus_num(org_bus_num);
>> +    return ret;
>> +
> extra eol?
Done.  Next patchset
>> +}
>> +
>> +static int tca642x_reg_read(uint8_t chip, uint addr, uint *data)
> same here? addr is u8, data is u8 *?
Done.  Next patchset
>> +{
>> +    uint16_t valw;
> val as u8?
Done.  Next patchset
>> +    int org_bus_num;
>> +    int ret = 0;
>> +
>> +    org_bus_num = i2c_get_bus_num();
>> +    i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
>> +    if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
>> +        ret = -1;
>> +        goto error;
>> +    }
>> +
>> +    *data = (int)valw;
>> +
>> +error:
>> +    i2c_set_bus_num(org_bus_num);
>> +    return ret;
>> +}
> [...]
Nishanth Menon - July 9, 2013, 4:21 p.m.
On 07/09/2013 11:17 AM, Dan Murphy wrote:

> On 07/08/2013 04:27 PM, Nishanth Menon wrote:
>> On 07/08/2013 03:53 PM, Dan Murphy wrote:
[...]
>>> +/* tca642x register address definitions */
>>> +struct tca642x_bank_info tca642x_banks[] = {
>>> +    {0x00, 0x04, 0x08, 0x0c},
>>> +    {0x01, 0x05, 0x09, 0x0d},
>>> +    {0x02, 0x06, 0x0a, 0x0e},
>> could we use explicit map of the struct params? helps any future
>> expansion.
>>
> Not sure what you are looking for here.  These are the register
> addresses within the chip.

something like
{.input_reg = 0x00, .polarity_reg = 0x04, ....

It helps readability and future modification to bank_info structure.

[..]
>>> +    int org_bus_num;
>>> +    int ret;
>>> +
>>> +    org_bus_num = i2c_get_bus_num();
>>> +    i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
>>> +
>>> +    if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
>>> +        printf("Could not read before writing\n");
>>> +        ret = -1;
>>> +        goto error;
>>> +    }
>>> +    valw &= ~mask;
>> data &= mask ?
> Well in this case the mask is not being passed in.  The bit to flip is
> being passed and then the actual mask
> is created here.

reg_setbits? instead then? following the standard api convention - maybe 
make this as a i2c generic api?

Patch

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f77c1ec..7e74dfe 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -49,6 +49,7 @@  COBJS-$(CONFIG_BCM2835_GPIO)	+= bcm2835_gpio.o
 COBJS-$(CONFIG_S3C2440_GPIO)	+= s3c2440_gpio.o
 COBJS-$(CONFIG_XILINX_GPIO)	+= xilinx_gpio.o
 COBJS-$(CONFIG_ADI_GPIO2)	+= adi_gpio2.o
+COBJS-$(CONFIG_TCA642X)		+= tca642x.o
 
 COBJS	:= $(COBJS-y)
 SRCS 	:= $(COBJS:.o=.c)
diff --git a/drivers/gpio/tca642x.c b/drivers/gpio/tca642x.c
new file mode 100644
index 0000000..740714d
--- /dev/null
+++ b/drivers/gpio/tca642x.c
@@ -0,0 +1,312 @@ 
+/*
+ * Copyright 2013 Texas Instruments, Inc.
+ *
+ * Derived work from the pca953x.c driver
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <tca642x.h>
+
+/* tca642x register address definitions */
+struct tca642x_bank_info tca642x_banks[] = {
+	{0x00, 0x04, 0x08, 0x0c},
+	{0x01, 0x05, 0x09, 0x0d},
+	{0x02, 0x06, 0x0a, 0x0e},
+};
+
+/*
+ * Modify masked bits in register
+ */
+static int tca642x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
+{
+	uint16_t valw;
+	int org_bus_num;
+	int ret;
+
+	org_bus_num = i2c_get_bus_num();
+	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
+
+	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
+		printf("Could not read before writing\n");
+		ret = -1;
+		goto error;
+	}
+	valw &= ~mask;
+	valw |= data;
+
+	ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
+
+error:
+	i2c_set_bus_num(org_bus_num);
+	return ret;
+
+}
+
+static int tca642x_reg_read(uint8_t chip, uint addr, uint *data)
+{
+	uint16_t valw;
+	int org_bus_num;
+	int ret = 0;
+
+	org_bus_num = i2c_get_bus_num();
+	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
+	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
+		ret = -1;
+		goto error;
+	}
+
+	*data = (int)valw;
+
+error:
+	i2c_set_bus_num(org_bus_num);
+	return ret;
+}
+
+/*
+ * Set output value of IO pins in 'mask' to corresponding value in 'data'
+ * 0 = low, 1 = high
+ */
+int tca642x_set_val(uint8_t chip, u8 gpio_bank, uint mask, uint data)
+{
+	uint out_reg = tca642x_banks[gpio_bank].output_reg;
+
+	return tca642x_reg_write(chip, out_reg, 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 tca642x_set_pol(uint8_t chip, u8 gpio_bank, uint mask, uint data)
+{
+	uint pol_reg = tca642x_banks[gpio_bank].polarity_reg;
+
+	return tca642x_reg_write(chip, pol_reg, mask, data);
+}
+
+/*
+ * Set direction of IO pins in 'mask' to corresponding value in 'data'
+ * 0 = output, 1 = input
+ */
+int tca642x_set_dir(uint8_t chip, u8 gpio_bank, uint mask, uint data)
+{
+	uint config_reg = tca642x_banks[gpio_bank].configuration_reg;
+
+	return tca642x_reg_write(chip, config_reg, mask, data);
+}
+
+/*
+ * Read current logic level of all IO pins
+ */
+int tca642x_get_val(uint8_t chip, u8 gpio_bank)
+{
+	uint val;
+	uint in_reg = tca642x_banks[gpio_bank].input_reg;
+
+	if (tca642x_reg_read(chip, in_reg, &val) < 0)
+		return -1;
+
+	return (int)val;
+}
+
+/*
+ * Set the inital register states for the tca642x gpio expander
+ */
+int tca642x_set_inital_state(uint8_t chip, struct tca642x_bank_info init_data[])
+{
+	int i, ret;
+	uint config_reg;
+	uint polarity_reg;
+	uint output_reg;
+
+	for (i = 0; i < 3; i++) {
+		config_reg = tca642x_banks[i].configuration_reg;
+		ret = tca642x_reg_write(chip, config_reg, 0xff,
+				init_data[i].configuration_reg);
+		polarity_reg = tca642x_banks[i].polarity_reg;
+		ret = tca642x_reg_write(chip, polarity_reg, 0xff,
+				init_data[i].polarity_reg);
+		output_reg = tca642x_banks[i].output_reg;
+		ret = tca642x_reg_write(chip, output_reg, 0xff,
+				init_data[i].output_reg);
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_CMD_TCA642X
+/*
+ * Display tca642x information
+ */
+static int tca642x_info(uint8_t chip)
+{
+	int i, j;
+	uint data;
+
+	printf("tca642x@ 0x%x (%d pins):\n", chip, 24);
+	for (i = 0; i < 3; i++) {
+		printf("Bank %i\n", i);
+		if (tca642x_reg_read(chip, tca642x_banks[i].configuration_reg, &data) < 0)
+			return -1;
+		printf("\tConfiguration: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? 'i' : 'o');
+		printf("\n");
+
+		if (tca642x_reg_read(chip, tca642x_banks[i].polarity_reg, &data) < 0)
+			return -1;
+		printf("\tPolarity: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? '1' : '0');
+		printf("\n");
+
+		if (tca642x_reg_read(chip, tca642x_banks[i].input_reg, &data) < 0)
+			return -1;
+		printf("\tInput value: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? '1' : '0');
+		printf("\n");
+
+		if (tca642x_reg_read(chip, tca642x_banks[i].output_reg, &data) < 0)
+			return -1;
+		printf("\tOutput value: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? '1' : '0');
+		printf("\n");
+	}
+
+	return 0;
+}
+
+cmd_tbl_t cmd_tca642x[] = {
+	U_BOOT_CMD_MKENT(device, 3, 0, (void *)TCA642X_CMD_DEVICE, "", ""),
+	U_BOOT_CMD_MKENT(output, 4, 0, (void *)TCA642X_CMD_OUTPUT, "", ""),
+	U_BOOT_CMD_MKENT(input, 3, 0, (void *)TCA642X_CMD_INPUT, "", ""),
+	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)TCA642X_CMD_INVERT, "", ""),
+	U_BOOT_CMD_MKENT(info, 2, 0, (void *)TCA642X_CMD_INFO, "", ""),
+};
+
+int do_tca642x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	static uint8_t chip = CONFIG_SYS_I2C_TCA642X_ADDR;
+	int ret = CMD_RET_USAGE, val;
+	u8 gpio_bank;
+	u8 bank_shift;
+	ulong ul_arg2 = 0;
+	ulong ul_arg3 = 0;
+	cmd_tbl_t *c;
+
+	c = find_cmd_tbl(argv[1], cmd_tca642x, ARRAY_SIZE(cmd_tca642x));
+
+	/* All commands but "device" require 'maxargs' arguments */
+	if (!c || !((argc == (c->maxargs)) ||
+		(((int)c->cmd == TCA642X_CMD_DEVICE) &&
+		 (argc == (c->maxargs - 1))))) {
+		return CMD_RET_USAGE;
+	}
+
+	/* arg2 used as chip number or pin number */
+	if (argc > 2)
+		ul_arg2 = simple_strtoul(argv[2], NULL, 10);
+
+	/* arg3 used as pin or invert value */
+	if (argc > 3) {
+		ul_arg3 = simple_strtoul(argv[3], NULL, 10) & 0x1;
+		if (ul_arg2 <= 7)
+			gpio_bank = 0;
+		else if ((ul_arg2 >= 10) && (ul_arg2 <= 17))
+			gpio_bank = 1;
+		else if ((ul_arg2 >= 20) && (ul_arg2 <= 27))
+			gpio_bank = 2;
+		else {
+			printf("Requested pin is not available\n");
+			ret = CMD_RET_FAILURE;
+			goto error;
+		}
+	}
+
+	switch ((int)c->cmd) {
+	case TCA642X_CMD_INFO:
+		ret = tca642x_info(chip);
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		break;
+
+	case TCA642X_CMD_DEVICE:
+		if (argc == 3)
+			chip = (uint8_t)ul_arg2;
+		printf("Current device address: 0x%x\n", chip);
+		ret = CMD_RET_SUCCESS;
+		break;
+
+	case TCA642X_CMD_INPUT:
+		bank_shift = ul_arg2 - (gpio_bank * 10);
+		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
+				TCA642X_DIR_IN << bank_shift);
+		val = (tca642x_get_val(chip, gpio_bank) & (1 << bank_shift)) != 0;
+
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		else
+			printf("chip 0x%02x, pin 0x%lx = %d\n", chip, ul_arg2,
+									val);
+		break;
+
+	case TCA642X_CMD_OUTPUT:
+		bank_shift = ul_arg2 - (gpio_bank * 10);
+		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
+				(TCA642X_DIR_OUT << bank_shift));
+		if (!ret)
+			ret = tca642x_set_val(chip, gpio_bank, (1 << bank_shift),
+						(ul_arg3 << bank_shift));
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		break;
+
+	case TCA642X_CMD_INVERT:
+		bank_shift = ul_arg2 - (gpio_bank * 10);
+		ret = tca642x_set_pol(chip, gpio_bank, (1 << bank_shift),
+					(ul_arg3 << bank_shift));
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		break;
+
+	}
+error:
+	if (ret == CMD_RET_FAILURE)
+		eprintf("Error talking to chip at 0x%x\n", chip);
+
+	return ret;
+}
+
+U_BOOT_CMD(
+	tca642x,	5,	1,	do_tca642x,
+	"tca642x gpio access",
+	"device [dev]\n"
+	"	- show or set current device address\n"
+	"tca642x info\n"
+	"	- display info for current chip\n"
+	"tca642x output pin 0|1\n"
+	"	- set pin as output and drive low or high\n"
+	"tca642x invert pin 0|1\n"
+	"	- disable/enable polarity inversion for reads\n"
+	"tca642x input pin\n"
+	"	- set pin as input and read value"
+);
+
+#endif /* CONFIG_CMD_TCA642X */
diff --git a/include/tca642x.h b/include/tca642x.h
new file mode 100644
index 0000000..2ca34a7
--- /dev/null
+++ b/include/tca642x.h
@@ -0,0 +1,64 @@ 
+/*
+ * Copyright 2013 Texas Instruments, Inc.
+ *
+ * Derived work from the pca953x.c driver
+ *
+ * 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 __TCA642X_H_
+#define __TCA642X_H_
+
+#ifdef CONFIG_CMD_TCA642X
+enum {
+	TCA642X_CMD_INFO,
+	TCA642X_CMD_DEVICE,
+	TCA642X_CMD_OUTPUT,
+	TCA642X_CMD_INPUT,
+	TCA642X_CMD_INVERT,
+};
+#endif
+
+#define TCA642X_OUT_LOW		0
+#define TCA642X_OUT_HIGH	1
+#define TCA642X_POL_NORMAL	0
+#define TCA642X_POL_INVERT	1
+#define TCA642X_DIR_OUT		0
+#define TCA642X_DIR_IN		1
+
+/* Default to an address that hopefully won't corrupt other i2c devices */
+#ifndef CONFIG_SYS_I2C_TCA642X_ADDR
+#define CONFIG_SYS_I2C_TCA642X_ADDR	(~0)
+#endif
+
+/* Default to an address that hopefully won't corrupt other i2c devices */
+#ifndef CONFIG_SYS_I2C_TCA642X_BUS_NUM
+#define CONFIG_SYS_I2C_TCA642X_BUS_NUM	(0)
+#endif
+
+struct tca642x_bank_info {
+	uint8_t input_reg;
+	uint8_t output_reg;
+	uint8_t polarity_reg;
+	uint8_t configuration_reg;
+};
+
+int tca642x_set_val(u8 chip, u8 gpio_bank, uint mask, uint data);
+int tca642x_set_pol(u8 chip, u8 gpio_bank, uint mask, uint data);
+int tca642x_set_dir(u8 chip, u8 gpio_bank, uint mask, uint data);
+int tca642x_get_val(u8 chip, u8 gpio_bank);
+int tca642x_set_inital_state(uint8_t chip, struct tca642x_bank_info init_data[]);
+
+#endif /* __TCA642X_H_ */