From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>,
Wolfram Sang <wsa@the-dreams.de>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Serge Semin <fancer.lancer@gmail.com>,
Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Rob Herring <robh+dt@kernel.org>,
devicetree@vger.kernel.org, linux-mips@vger.kernel.org,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 08/11] i2c: designware: Convert driver to using regmap API
Date: Wed, 27 May 2020 16:50:23 +0300 [thread overview]
Message-ID: <20200527135023.GZ1634618@smile.fi.intel.com> (raw)
In-Reply-To: <20200527120111.5781-9-Sergey.Semin@baikalelectronics.ru>
On Wed, May 27, 2020 at 03:01:08PM +0300, Serge Semin wrote:
> Seeing the DW I2C driver is using flags-based accessors with two
> conditional clauses it would be better to replace them with the regmap
> API IO methods and to initialize the regmap object with read/write
> callbacks specific to the controller registers map implementation. This
> will be also handy for the drivers with non-standard registers mapping
> (like an embedded into the Baikal-T1 System Controller DW I2C block, which
> glue-driver is a part of this series).
>
> As before the driver tries to detect the mapping setup at probe stage and
> creates a regmap object accordingly, which will be used by the rest of the
> code to correctly access the controller registers. In two places it was
> appropriate to convert the hand-written read-modify-write and
> read-poll-loop design patterns to the corresponding regmap API
> ready-to-use methods.
>
> Note the regmap IO methods return value is checked only at the probe
> stage. The rest of the code won't do this because basically we have
> MMIO-based regmap so non of the read/write methods can fail (this also
> won't be needed for the Baikal-T1-specific I2C controller).
Thanks! My comments below.
...
> #include <linux/export.h>
> #include <linux/i2c.h>
> #include <linux/interrupt.h>
> +#include <linux/regmap.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
Please, keep ordered.
...
> +static int dw_reg_write_word(void *context, unsigned int reg, unsigned int val)
> +{
> + struct dw_i2c_dev *dev = context;
> +
> + writew_relaxed((u16)val, dev->base + reg);
> + writew_relaxed((u16)(val >> 16), dev->base + reg + 2);
What does explicit casting here help to?
I think you may drop it.
> + return 0;
> }
...
> #include <linux/errno.h>
> #include <linux/i2c.h>
> #include <linux/interrupt.h>
> +#include <linux/regmap.h>
> #include <linux/io.h>
> #include <linux/module.h>
> #include <linux/pm_runtime.h>
Order?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2020-05-27 13:50 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-27 12:01 [PATCH v4 00/11] i2c: designeware: Add Baikal-T1 System I2C support Serge Semin
2020-05-27 12:01 ` [PATCH v4 01/11] dt-bindings: i2c: Convert DW I2C binding to DT schema Serge Semin
2020-05-27 12:01 ` [PATCH v4 02/11] dt-bindings: i2c: Discard i2c-slave flag from the DW I2C example Serge Semin
2020-05-27 17:12 ` Rob Herring
2020-05-27 17:18 ` Serge Semin
2020-05-27 17:56 ` Andy Shevchenko
2020-05-28 8:39 ` Serge Semin
2020-05-28 10:00 ` Andy Shevchenko
2020-05-27 12:01 ` [PATCH v4 03/11] dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller Serge Semin
2020-05-27 12:01 ` [PATCH v4 04/11] i2c: designware: Use `-y` to build multi-object modules Serge Semin
2020-05-27 12:01 ` [PATCH v4 05/11] i2c: designware: slave: Set DW I2C core module dependency Serge Semin
2020-05-27 12:01 ` [PATCH v4 06/11] i2c: designware: Add Baytrail sem config DW I2C platform dependency Serge Semin
2020-05-27 13:42 ` Andy Shevchenko
2020-05-27 14:24 ` Serge Semin
2020-05-27 15:46 ` Andy Shevchenko
2020-05-27 16:00 ` Serge Semin
2020-05-27 16:43 ` Andy Shevchenko
2020-05-27 12:01 ` [PATCH v4 07/11] i2c: designware: Discard Cherry Trail model flag Serge Semin
2020-05-27 13:43 ` Andy Shevchenko
2020-05-27 14:29 ` Serge Semin
2020-05-27 15:48 ` Andy Shevchenko
2020-05-27 12:01 ` [PATCH v4 08/11] i2c: designware: Convert driver to using regmap API Serge Semin
2020-05-27 13:50 ` Andy Shevchenko [this message]
2020-05-27 14:39 ` Serge Semin
2020-05-27 12:01 ` [PATCH v4 09/11] i2c: designware: Retrieve quirk flags as early as possible Serge Semin
2020-05-27 13:51 ` Andy Shevchenko
2020-05-27 12:01 ` [PATCH v4 10/11] i2c: designware: Move reg-space remapping into a dedicated function Serge Semin
2020-05-27 13:58 ` Andy Shevchenko
2020-05-27 14:54 ` Serge Semin
2020-05-27 12:01 ` [PATCH v4 11/11] i2c: designware: Add Baikal-T1 System I2C support Serge Semin
2020-05-27 14:03 ` Andy Shevchenko
2020-05-27 15:04 ` Serge Semin
2020-05-27 15:52 ` Andy Shevchenko
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