Re: [PATCH v4] i2c: Add support for NXP PCA984x family.

[Peter Rosin <peda@axentia.se>]

On 2017-12-13 17:12, Adrian Fiergolski wrote:
> This patch exetends the current i2c-mux-pca954x driver and adds support for

extends

> a newer PCA984x family of the I2C switches and multiplexers from NXP.
> 
> Signed-off-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
> ---
> As suggested by Peter, for a moment the device_id checks have been removed
> and need to wait for a support in the I2C core.
>  .../devicetree/bindings/i2c/i2c-mux-pca954x.txt    |  5 ++-
>  drivers/i2c/muxes/Kconfig                          |  6 ++--
>  drivers/i2c/muxes/i2c-mux-pca954x.c                | 41 +++++++++++++++++++---
>  3 files changed, 43 insertions(+), 9 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> index aa097045a10e..b428bc0d81b1 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.txt
> @@ -1,10 +1,13 @@
>  * NXP PCA954x I2C bus switch
>  
> +The driver supports NXP PCA954x and PCA984x I2C mux/switch devices.
> +
>  Required Properties:
>  
>    - compatible: Must contain one of the following.
>      "nxp,pca9540", "nxp,pca9542", "nxp,pca9543", "nxp,pca9544",
> -    "nxp,pca9545", "nxp,pca9546", "nxp,pca9547", "nxp,pca9548"
> +    "nxp,pca9545", "nxp,pca9546", "nxp,pca9547", "nxp,pca9548",
> +    "nxp,pca9846", "nxp,pca9847", "nxp,pca9848", "nxp,pca9849"
>  
>    - reg: The I2C address of the device.
>  
> diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
> index 0f5c8fc36625..23cc41866a91 100644
> --- a/drivers/i2c/muxes/Kconfig
> +++ b/drivers/i2c/muxes/Kconfig
> @@ -64,11 +64,11 @@ config I2C_MUX_PCA9541
>  	  will be called i2c-mux-pca9541.
>  
>  config I2C_MUX_PCA954x
> -	tristate "Philips PCA954x I2C Mux/switches"
> +	tristate "NXP PCA954x I2C Mux/switches"

I think you should perhaps mention PCA984x here in the headline.

>  	depends on GPIOLIB || COMPILE_TEST
>  	help
> -	  If you say yes here you get support for the Philips PCA954x
> -	  I2C mux/switch devices.
> +	  If you say yes here you get support for the NXP PCA954x
> +	  and PCA984x I2C mux/switch devices.
>  
>  	  This driver can also be built as a module.  If so, the module
>  	  will be called i2c-mux-pca954x.
> diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
> index 2ca068d8b92d..b4a41d013538 100644
> --- a/drivers/i2c/muxes/i2c-mux-pca954x.c
> +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
> @@ -1,14 +1,15 @@
>  /*
>   * I2C multiplexer
>   *
> + * Copyright (c) 2017 Adrian Fiergolski <Adrian.Fiergolski@cern.ch>

This is a bit over the top when you only add data with questionable
copyright value.

>   * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
>   * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
>   *
> - * This module supports the PCA954x series of I2C multiplexer/switch chips
> - * made by Philips Semiconductors.
> + * This module supports the PCA954x and PCA954x series of I2C multiplexer/switch
> + * chips made by NXP Semiconductors.
>   * This includes the:
> - *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
> - *	 and PCA9548.
> + *	 PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547,
> + *	 PCA9548, PCA9846, PCA9847, PCA9848 and PCA9849

The trailing . is missing.

>   *
>   * These chips are all controlled via the I2C bus itself, and all have a
>   * single 8-bit register. The upstream "parent" bus fans out to two,
> @@ -63,6 +64,10 @@ enum pca_type {
>  	pca_9546,
>  	pca_9547,
>  	pca_9548,
> +	pca_9846,
> +	pca_9847,
> +	pca_9848,
> +	pca_9849,
>  };
>  
>  struct chip_desc {
> @@ -129,6 +134,22 @@ static const struct chip_desc chips[] = {
>  		.nchans = 8,
>  		.muxtype = pca954x_isswi,
>  	},
> +	[pca_9846] = {
> +		.nchans = 4,
> +		.muxtype = pca954x_isswi,
> +	},
> +	[pca_9847] = {
> +		.nchans = 8,
> +		.muxtype = pca954x_ismux,
> +	},
> +	[pca_9848] = {
> +		.nchans = 8,
> +		.muxtype = pca954x_isswi,
> +	},
> +	[pca_9849] = {
> +		.nchans = 4,
> +		.muxtype = pca954x_ismux,
> +	},
>  };
>  
>  static const struct i2c_device_id pca954x_id[] = {
> @@ -140,6 +161,10 @@ static const struct i2c_device_id pca954x_id[] = {
>  	{ "pca9546", pca_9546 },
>  	{ "pca9547", pca_9547 },
>  	{ "pca9548", pca_9548 },
> +	{ "pca9846", pca_9846 },
> +	{ "pca9847", pca_9847 },
> +	{ "pca9848", pca_9848 },
> +	{ "pca9849", pca_9849 },
>  	{ }
>  };
>  MODULE_DEVICE_TABLE(i2c, pca954x_id);
> @@ -154,6 +179,10 @@ static const struct of_device_id pca954x_of_match[] = {
>  	{ .compatible = "nxp,pca9546", .data = &chips[pca_9546] },
>  	{ .compatible = "nxp,pca9547", .data = &chips[pca_9547] },
>  	{ .compatible = "nxp,pca9548", .data = &chips[pca_9548] },
> +	{ .compatible = "nxp,pca9846", .data = &chips[pca_9846] },
> +	{ .compatible = "nxp,pca9847", .data = &chips[pca_9847] },
> +	{ .compatible = "nxp,pca9848", .data = &chips[pca_9848] },
> +	{ .compatible = "nxp,pca9849", .data = &chips[pca_9849] },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, pca954x_of_match);
> @@ -339,7 +368,8 @@ static int pca954x_probe(struct i2c_client *client,
>  	if (IS_ERR(gpio))
>  		return PTR_ERR(gpio);
>  
> -	/* Write the mux register at addr to verify
> +	/*
> +	 * Write the mux register at addr to verify

This is now unrelated and belongs in a separate patch.

>  	 * that the mux is in fact present. This also
>  	 * initializes the mux to disconnected state.
>  	 */
> @@ -443,6 +473,7 @@ static struct i2c_driver pca954x_driver = {
>  
>  module_i2c_driver(pca954x_driver);
>  
> +MODULE_AUTHOR("Adrian Fiergolski <Adrian.Fiergolski@cern.ch>");

And, just as Wolfram said, this is not appropriate anymore. Next
time you should probably ask before adding authorship to an existing
file, that makes you look better. Unless you do some major addition
of course... But when you do add yourself, add yourself last so that
it doesn't look like you are the principal author. Unless you did
some really serious surgery of course...

Anyway, with those changes things are getting in shape.

Thanks for your patience!

Cheers,
Peter

>  MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
>  MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
>  MODULE_LICENSE("GPL v2");
>