From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nishanth Menon <nm@ti.com>
Date: Mon, 8 Jul 2013 16:27:57 -0500
Subject: [U-Boot] [PATCH 1/2] gpio: tca642x: Add the tca642x gpio
 expander driver
In-Reply-To: <1373316840-28436-1-git-send-email-dmurphy@ti.com>
References: <1373316840-28436-1-git-send-email-dmurphy@ti.com>
Message-ID: <51DB2EDD.5040107@ti.com>
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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;
> +}
[...]
-- 
Regards,
Nishanth Menon