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

Nishanth Menon
2013-07-08T21:27:57Z

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