lkml.org 
[lkml]   [2021]   [Aug]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
SubjectRe: [PATCH v2 1/1] mfd: simple-mfd-i2c: Add support for registering devices via MFD cells
On Thu, Aug 5, 2021 at 6:56 PM Lee Jones <lee.jones@linaro.org> wrote:
>
> More devices are cropping up requiring only Regmap initialisation and
> child registration functionality. We currently only support that if
> all required devices are represented by their own Device Tree nodes
> complete with compatible strings.
>
> However, not everyone is happy with adding empty nodes that provide no
> additional device information into the Device Tree.
>
> Rather than have a plethora of mostly empty, function-less drivers in
> MFD, we'll support those simple cases in here instead via MFD cells.
>
> Cc: Michael Walle <michael@walle.cc>
> Cc: Mark Brown <broonie@kernel.org>
> Cc: Alistair Francis <alistair23@gmail.com>
> Signed-off-by: Lee Jones <lee.jones@linaro.org>
> ---
> v2:
> - Check for empty of_device_id .data entry
>
> drivers/mfd/simple-mfd-i2c.c | 41 +++++++++++++++++++++++++++++-------
> drivers/mfd/simple-mfd-i2c.h | 32 ++++++++++++++++++++++++++++
> 2 files changed, 65 insertions(+), 8 deletions(-)
> create mode 100644 drivers/mfd/simple-mfd-i2c.h
>
> diff --git a/drivers/mfd/simple-mfd-i2c.c b/drivers/mfd/simple-mfd-i2c.c
> index 87f684cff9a17..583e8c7924af0 100644
> --- a/drivers/mfd/simple-mfd-i2c.c
> +++ b/drivers/mfd/simple-mfd-i2c.c
> @@ -2,39 +2,64 @@
> /*
> * Simple MFD - I2C
> *
> + * Author(s):
> + * Michael Walle <michael@walle.cc>
> + * Lee Jones <lee.jones@linaro.org>
> + *
> * This driver creates a single register map with the intention for it to be
> * shared by all sub-devices. Children can use their parent's device structure
> * (dev.parent) in order to reference it.
> *
> * Once the register map has been successfully initialised, any sub-devices
> - * represented by child nodes in Device Tree will be subsequently registered.
> + * represented by child nodes in Device Tree or via the MFD cells in this file
> + * will be subsequently registered.
> */
>
> #include <linux/i2c.h>
> #include <linux/kernel.h>
> +#include <linux/mfd/core.h>
> #include <linux/module.h>
> #include <linux/of_platform.h>
> #include <linux/regmap.h>
>
> -static const struct regmap_config simple_regmap_config = {
> +#include "simple-mfd-i2c.h"
> +
> +static const struct regmap_config regmap_config_8r_8v = {
> .reg_bits = 8,
> .val_bits = 8,
> };
>
> static int simple_mfd_i2c_probe(struct i2c_client *i2c)
> {
> - const struct regmap_config *config;
> + const struct simple_mfd_data *simple_mfd_data;
> + const struct regmap_config *regmap_config;
> struct regmap *regmap;
> + int ret;
> +
> + simple_mfd_data = device_get_match_data(&i2c->dev);
>
> - config = device_get_match_data(&i2c->dev);
> - if (!config)
> - config = &simple_regmap_config;
> + /* If no regmap_config is specified, use the default 8reg and 8val bits */
> + if (!simple_mfd_data || !simple_mfd_data->regmap_config)
> + regmap_config = &regmap_config_8r_8v;
> + else
> + regmap_config = simple_mfd_data->regmap_config;
>
> - regmap = devm_regmap_init_i2c(i2c, config);
> + regmap = devm_regmap_init_i2c(i2c, regmap_config);
> if (IS_ERR(regmap))
> return PTR_ERR(regmap);
>
> - return devm_of_platform_populate(&i2c->dev);
> + /* If no MFD cells are spedified, use register the DT child nodes instead */
> + if (!simple_mfd_data || !simple_mfd_data->mfd_cell)
> + return devm_of_platform_populate(&i2c->dev);
> +
> + ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO,
> + simple_mfd_data->mfd_cell,
> + simple_mfd_data->mfd_cell_size,
> + NULL, 0, NULL);
> + if (!ret)

Shouldn't this be `if (ret)` instead?

With that changed this works for me as well:

Reviewed-by: Alistair Francis <alistair@alistair23.me>
Tested-by: Alistair Francis <alistair@alistair23.me>

Alistair

> + dev_err(&i2c->dev, "Failed to add child devices\n");
> +
> + return ret;
> }
>
> static const struct of_device_id simple_mfd_i2c_of_match[] = {
> diff --git a/drivers/mfd/simple-mfd-i2c.h b/drivers/mfd/simple-mfd-i2c.h
> new file mode 100644
> index 0000000000000..7cb2bdd347d97
> --- /dev/null
> +++ b/drivers/mfd/simple-mfd-i2c.h
> @@ -0,0 +1,32 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Simple MFD - I2C
> + *
> + * Author: Lee Jones <lee.jones@linaro.org>
> + *
> + * This driver creates a single register map with the intention for it to be
> + * shared by all sub-devices. Children can use their parent's device structure
> + * (dev.parent) in order to reference it.
> + *
> + * This driver creates a single register map with the intention for it to be
> + * shared by all sub-devices. Children can use their parent's device structure
> + * (dev.parent) in order to reference it.
> + *
> + * Once the register map has been successfully initialised, any sub-devices
> + * represented by child nodes in Device Tree or via the MFD cells in the
> + * associated C file will be subsequently registered.
> + */
> +
> +#ifndef __MFD_SIMPLE_MFD_I2C_H
> +#define __MFD_SIMPLE_MFD_I2C_H
> +
> +#include <linux/mfd/core.h>
> +#include <linux/regmap.h>
> +
> +struct simple_mfd_data {
> + const struct regmap_config *regmap_config;
> + const struct mfd_cell *mfd_cell;
> + size_t mfd_cell_size;
> +};
> +
> +#endif /* __MFD_SIMPLE_MFD_I2C_H */
> --
> 2.32.0.605.g8dce9f2422-goog

\
 
 \ /
  Last update: 2021-08-06 10:28    [W:0.051 / U:0.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site