From: Dmitry Osipenko <digetx@gmail.com>
To: Lee Jones <lee.jones@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>,
Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Dan Murphy <dmurphy@ti.com>, Sebastian Reichel <sre@kernel.org>,
devicetree@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/4] mfd: Add driver for Embedded Controller found on Acer Iconia Tab A500
Date: Mon, 16 Nov 2020 02:12:28 +0300 [thread overview]
Message-ID: <3ad644fd-cd03-a1e1-36d9-014304fdfcee@gmail.com> (raw)
In-Reply-To: <20201113093747.GJ2787115@dell>
13.11.2020 12:37, Lee Jones пишет:
...
>> +config MFD_ACER_A500_EC
>> + tristate "Embedded Controller driver for Acer Iconia Tab A500"
>
> Drop "driver". This is meant to be describing the device.
>
>> + depends on I2C
>
> depends on OF ?
...
>> + depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
>> + select MFD_CORE
>> + select REGMAP
>> + help
ARCH_TEGRA_2x_SOC selects OF.
For COMPILE_TEST it doesn't matter since OF framework provides stubs for
!OF.
...
>> +static int a500_ec_read(void *context, const void *reg_buf, size_t reg_size,
>> + void *val_buf, size_t val_sizel)
>> +{
>> + struct i2c_client *client = context;
>> + unsigned int reg, retries = 5;
>> + u16 *ret_val = val_buf;
>> + s32 ret = 0;
>> +
>> + if (reg_size != 1 || val_sizel != 2)
>
> No magic numbers please.
>
> What does this *mean*?
These are the size of address register and size of a read value, both in
bytes.
>> + return -EOPNOTSUPP;
>
> Why EOPNOTSUPP?
Other sizes aren't supported by embedded controller.
Although, perhaps this check isn't really needed at all since the sizes
are already expressed in the a500_ec_regmap_config.
I'll need to take a closer look at why this size-checking was added
because don't quite remember already. If it's not needed, then I'll
remove it in the next revision, otherwise will add a clarifying comment.
>> + reg = *(u8 *)reg_buf;
>> +
>> + while (retries-- > 0) {
>> + ret = i2c_smbus_read_word_data(client, reg);
>> + if (ret >= 0)
>> + break;
>> +
>> + msleep(A500_EC_I2C_ERR_TIMEOUT);
>> + }
>> +
>> + if (ret < 0) {
>> + dev_err(&client->dev, "read 0x%x failed: %d\n", reg, ret);
>> + return ret;
>> + }
>> +
>> + *ret_val = ret;
>> +
>> + if (reg == REG_CURRENT_NOW)
>> + fsleep(10000);
>
> Ooo, new toy!
>
>> + return 0;
>> +}
>
> I'm surprised there isn't a generic function which does this kind of
> read. Seems like pretty common/boilerplate stuff.
I'm not quite sure that this is a really very common pattern which
deserves a generic helper.
...
>> +static int a500_ec_restart_notify(struct notifier_block *this,
>> + unsigned long reboot_mode, void *data)
>> +{
>> + if (reboot_mode == REBOOT_WARM)
>> + i2c_smbus_write_word_data(a500_ec_client_pm_off,
>> + REG_WARM_REBOOT, 0);
>> + else
>> + i2c_smbus_write_word_data(a500_ec_client_pm_off,
>> + REG_COLD_REBOOT, 1);
>
> What's with the magic '0' and '1's at the end?
These are the values which controller's firmware wants to see, otherwise
it will reject command as invalid. I'll add a clarifying comment to the
code.
Thank you for the review. I'll address all the comments in the v7.
next prev parent reply other threads:[~2020-11-15 23:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-04 20:33 [PATCH v5 0/4] Introduce Embedded Controller driver for Acer A500 Dmitry Osipenko
2020-11-04 20:34 ` [PATCH v5 1/4] dt-bindings: mfd: Add ENE KB930 Embedded Controller binding Dmitry Osipenko
2020-11-06 16:11 ` Rob Herring
2020-11-04 20:34 ` [PATCH v5 2/4] mfd: Add driver for Embedded Controller found on Acer Iconia Tab A500 Dmitry Osipenko
2020-11-13 9:37 ` Lee Jones
2020-11-15 23:12 ` Dmitry Osipenko [this message]
2020-11-16 8:48 ` Lee Jones
2020-11-16 9:53 ` Dmitry Osipenko
2020-11-16 10:29 ` Lee Jones
2020-11-04 20:34 ` [PATCH v5 3/4] power: supply: Add battery gauge driver for " Dmitry Osipenko
2020-11-04 20:34 ` [PATCH v5 4/4] ARM: tegra: acer-a500: Add Embedded Controller Dmitry Osipenko
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