[U-Boot] [PATCH 4/4] i2c: muxes: Add support for TI PCA954X mux

[Michal Simek]

On 20.4.2016 16:41, Simon Glass wrote:
> Hi Michal,
> 
> On 14 April 2016 at 06:15, Michal Simek <michal.simek at xilinx.com> wrote:
>> Add support for common TI i2c mux which is available on ZynqMP zcu102
>> board.
>> DM i2c mux core code is selecting/deselecting bus before/after
>> every command is performed that's why only one channel is active at a
>> time. That's also the reason why deselect is just disable all available
>> channels.
>>
>> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
>> ---
>>
>>  drivers/i2c/muxes/Kconfig   |  7 ++++
>>  drivers/i2c/muxes/Makefile  |  1 +
>>  drivers/i2c/muxes/pca954x.c | 79 +++++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 87 insertions(+)
>>  create mode 100644 drivers/i2c/muxes/pca954x.c
> 
> nits below, but otherwise:
> 
> 
> Reviewed-by: Simon Glass <sjg at chromium.org>
>>
>> diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
>> index f959d9de9e8b..e16b902f9611 100644
>> --- a/drivers/i2c/muxes/Kconfig
>> +++ b/drivers/i2c/muxes/Kconfig
>> @@ -24,3 +24,10 @@ config I2C_ARB_GPIO_CHALLENGE
>>           I2C multimaster arbitration scheme using GPIOs and a challenge &
>>           response mechanism where masters have to claim the bus by asserting
>>           a GPIO.
>> +
>> +config I2C_MUX_PCA954X
>> +        tristate "TI PCA954x I2C Mux/switches"
>> +        depends on I2C_MUX
>> +        help
>> +          If you say yes here you get support for the TI PCA954x
>> +          I2C mux/switch devices.
> 
> Can you add a few lines about what this device is? What does it allow?

done.

> 
>> diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
>> index 47c1240d7e9e..fb2d67ec9a97 100644
>> --- a/drivers/i2c/muxes/Makefile
>> +++ b/drivers/i2c/muxes/Makefile
>> @@ -5,3 +5,4 @@
>>  #
>>  obj-$(CONFIG_I2C_ARB_GPIO_CHALLENGE) += i2c-arb-gpio-challenge.o
>>  obj-$(CONFIG_$(SPL_)I2C_MUX) += i2c-mux-uclass.o
>> +obj-$(CONFIG_I2C_MUX_PCA954X) += pca954x.o
>> diff --git a/drivers/i2c/muxes/pca954x.c b/drivers/i2c/muxes/pca954x.c
>> new file mode 100644
>> index 000000000000..206581d3d908
>> --- /dev/null
>> +++ b/drivers/i2c/muxes/pca954x.c
>> @@ -0,0 +1,79 @@
>> +/*
>> + * Copyright (C) 2015 - 2016 Xilinx, Inc.
>> + * Written by Michal Simek
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <dm.h>
>> +#include <errno.h>
>> +#include <i2c.h>
>> +#include <asm/gpio.h>
>> +
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>> +struct pca95xx_priv {
>> +       u32 addr;
> 
> ulong?

it is i2c address that's why 32bit address should be enough.

> 
>> +       u32 width;
> 
> Comments?

Added.

> 
>> +};
>> +
>> +static int pca95xx_deselect(struct udevice *mux, struct udevice *bus,
>> +                           uint channel)
>> +{
>> +       struct pca95xx_priv *priv = dev_get_priv(mux);
>> +       uchar byte = 0;
>> +
>> +       return dm_i2c_write(mux, priv->addr, &byte, 1);
>> +}
>> +
>> +static int pca95xx_select(struct udevice *mux, struct udevice *bus,
>> +                         uint channel)
>> +{
>> +       struct pca95xx_priv *priv = dev_get_priv(mux);
>> +       uchar byte = 1 << channel;
>> +
>> +       return dm_i2c_write(mux, priv->addr, &byte, 1);
>> +}
>> +
>> +static const struct i2c_mux_ops pca95xx_ops = {
>> +       .select = pca95xx_select,
>> +       .deselect = pca95xx_deselect,
>> +};
>> +
>> +static const struct udevice_id pca95xx_ids[] = {
>> +       { .compatible = "nxp,pca9548", .data = (ulong)8 },
>> +       { .compatible = "nxp,pca9544", .data = (ulong)4 },
>> +       { }
>> +};
>> +
>> +static int pca95xx_ofdata_to_platdata(struct udevice *dev)
>> +{
>> +       struct pca95xx_priv *priv = dev_get_priv(dev);
>> +
>> +       priv->addr = dev_get_addr(dev);
>> +       if (!priv->addr) {
>> +               debug("MUX not found\n");
>> +               return -ENOSYS;
> 
> -EINVAL

fixed.

> 
>> +       }
>> +       priv->width = dev_get_driver_data(dev);
>> +
>> +       if (!priv->width) {
>> +               debug("No I2C MUX width specified\n");
>> +               return -ENOSYS;
> 
> -EINVAL

fixed.

> 
>> +       }
>> +
>> +       debug("Device %s at 0x%x with width %d\n",
>> +             dev->name, priv->addr, priv->width);
>> +
>> +       return 0;
>> +}
>> +
>> +U_BOOT_DRIVER(pca95xx) = {
>> +       .name = "pca95xx",
>> +       .id = UCLASS_I2C_MUX,
>> +       .of_match = pca95xx_ids,
>> +       .ops = &pca95xx_ops,
>> +       .ofdata_to_platdata = pca95xx_ofdata_to_platdata,
>> +       .priv_auto_alloc_size = sizeof(struct pca95xx_priv),
>> +};
>> --
>> 1.9.1
>>
> 
> Regards,
> Simon
> 

Thanks,
Michal