From: Andy Shevchenko <andy@kernel.org>
To: "Marek Behún" <kabel@kernel.org>
Cc: Gregory CLEMENT <gregory.clement@bootlin.com>,
Arnd Bergmann <arnd@arndb.de>,
soc@kernel.org, arm@kernel.org,
Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <brgl@bgdev.pl>,
linux-gpio@vger.kernel.org,
Alessandro Zummo <a.zummo@towertech.it>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
linux-rtc@vger.kernel.org,
Wim Van Sebroeck <wim@linux-watchdog.org>,
Guenter Roeck <linux@roeck-us.net>,
linux-watchdog@vger.kernel.org
Subject: Re: [PATCH v2 2/7] platform: cznic: Add preliminary support for Turris Omnia MCU
Date: Tue, 19 Sep 2023 15:29:08 +0300 [thread overview]
Message-ID: <ZQmUFPvIx91+ps6k@smile.fi.intel.com> (raw)
In-Reply-To: <20230919103815.16818-3-kabel@kernel.org>
On Tue, Sep 19, 2023 at 12:38:10PM +0200, Marek Behún wrote:
> Add a new platform driver that exposes the features provided by the
> microcontroller on the Turris Omnia board.
> This commit adds the basic skeleton for the driver.
Read "Submitting Patches" documentation (find "This patch" in it) and amend
your commit message accordingly.
...
> +Date: August 2023
> +KernelVersion: 6.6
Wrong and outdated. Use phb-crystall-ball to find the closest possible values
for both parameters here.
Ditto for all others with the same issue.
Note, it likely might be part of v6.7, not earlier.
...
> @@ -11,3 +11,4 @@ obj-$(CONFIG_OLPC_EC) += olpc/
> obj-$(CONFIG_GOLDFISH) += goldfish/
> obj-$(CONFIG_CHROME_PLATFORMS) += chrome/
> obj-$(CONFIG_SURFACE_PLATFORMS) += surface/
> +obj-$(CONFIG_CZNIC_PLATFORMS) += cznic/
Why not ordered (to some extent) here (as you did in the other file)?
...
> +turris-omnia-mcu-objs := turris-omnia-mcu-base.o
objs is for user space tools. Kernel code should use m,y.
...
> +#include <linux/hex.h>
> +#include <linux/module.h>
Missing types.h, sysfs.h, mod_devicetable.h, i2c.h, ...
...
> +static int omnia_get_version_hash(struct omnia_mcu *mcu, bool bootloader,
> + u8 *version)
> +{
> + u8 reply[20];
> + int ret;
> +
> + ret = omnia_cmd_read(mcu->client, bootloader ? CMD_GET_FW_VERSION_BOOT :
> + CMD_GET_FW_VERSION_APP,
> + reply, sizeof(reply));
> + if (ret < 0)
Can it return positive value? What would be the meaning of it?
> + return ret;
> + version[40] = '\0';
How do you know the version has enough space?
> + bin2hex(version, reply, 20);
> +
> + return 0;
> +}
> +
> +static ssize_t fw_version_hash_show(struct device *dev, char *buf,
> + bool bootloader)
> +{
> + struct omnia_mcu *mcu = i2c_get_clientdata(to_i2c_client(dev));
> + u8 version[41];
> + int err;
In two near functions you already inconsistent in the naming of the return code
variable. Be consistent across all your code, i.e. choose one name and use it
everywhere.
> + err = omnia_get_version_hash(mcu, bootloader, version);
> + if (err)
> + return err;
> +
> + return sysfs_emit(buf, "%s\n", version);
> +}
...
> + return sysfs_emit(buf, "%#x\n", mcu->features);
"0" will be printed differently, is this on purpose?
...
> + int ret = omnia_cmd_read_u8(to_i2c_client(dev), CMD_GET_RESET);
> +
> + if (ret < 0)
> + return ret;
Better from maintenance perspective to have
int ret;
ret = omnia_cmd_read_u8(to_i2c_client(dev), CMD_GET_RESET);
if (ret < 0)
return ret;
...
> +static struct attribute *omnia_mcu_attrs[] = {
> + &dev_attr_fw_version_hash_application.attr,
> + &dev_attr_fw_version_hash_bootloader.attr,
> + &dev_attr_fw_features.attr,
> + &dev_attr_mcu_type.attr,
> + &dev_attr_reset_selector.attr,
> + NULL,
No comma for the terminator line. It will make your code robust at compile time
against some misplaced entries.
> +};
> +
Unneeded blank line.
> +ATTRIBUTE_GROUPS(omnia_mcu);
...
> + u8 version[41];
This magic sizes should go away. Use predefined constant, or allocate on the
heap, depending on the case(s) you have.
...
> + int status;
My gosh, it's a _third_ name for the same!
> + status = omnia_cmd_read_u16(mcu->client, CMD_GET_STATUS_WORD);
> + if (status < 0)
> + return status;
...
> + for (int i = 0; i < ARRAY_SIZE(features); ++i) {
Why signed?
Why pre-increment?
> + if (!(mcu->features & features[i].mask)) {
Wouldn't be better
if (mcu->features & features[i].mask)
continue;
?
> + omnia_info_missing_feature(dev, features[i].name);
> + suggest_fw_upgrade = true;
> + }
> + }
...
> + dev_info(dev,
> + "Consider upgrading MCU firmware with the omnia-mcutool utility.\n");
You have so-o many dev_info() calls, are you sure you not abusing use of that?
...
> + if (ret) {
> + dev_err(dev, "Cannot determine MCU supported features: %d\n",
> + ret);
> + return ret;
return dev_err_probe(...);
> + }
...
> + if (!client->irq) {
> + dev_err(dev, "IRQ resource not found\n");
> + return -ENODATA;
> + }
Why you need to allocate memory, go through the initial checks, etc and then
fail? What's wrong with checking this first?
Why -ENODATA?!
...
> +static const struct of_device_id of_omnia_mcu_match[] = {
> + { .compatible = "cznic,turris-omnia-mcu", },
Inner comma is not needed.
> + {},
No comma for the terminator entry.
> +};
...
> +static const struct i2c_device_id omnia_mcu_id[] = {
> + { "turris-omnia-mcu", 0 },
', 0' part is redundant.
> + { }
> +};
...
> +static struct i2c_driver omnia_mcu_driver = {
> + .probe = omnia_mcu_probe,
> + .id_table = omnia_mcu_id,
> + .driver = {
> + .name = "turris-omnia-mcu",
> + .of_match_table = of_omnia_mcu_match,
> + .dev_groups = omnia_mcu_groups,
> + },
> +};
> +
Redundant blank line.
> +module_i2c_driver(omnia_mcu_driver);
...
> +#ifndef __DRIVERS_PLATFORM_CZNIC_TURRIS_OMNIA_MCU_H
> +#define __DRIVERS_PLATFORM_CZNIC_TURRIS_OMNIA_MCU_H
WE_LIKE_VERY_LONG_AND_OVERFLOWED_DEFINITIONS_H!
...
> +#include <asm/byteorder.h>
This usually goes after linux/*.h.
> +#include <linux/i2c.h>
Missing types.h, errno.h, ...
+ blank line?
> +#include <linux/turris-omnia-mcu-interface.h>
...
> + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> + if (likely(ret == ARRAY_SIZE(msgs)))
Why likely()? Please, justify.
> + return len;
> + else if (ret < 0)
> + return ret;
> + else
> + return -EIO;
In both cases the 'else' is redundant. Moreover, the usual pattern is to check
for the errors first.
> +}
...
> +#ifndef __INCLUDE_LINUX_TURRIS_OMNIA_MCU_INTERFACE_H
> +#define __INCLUDE_LINUX_TURRIS_OMNIA_MCU_INTERFACE_H
My gosh!
...
> +#include <linux/bits.h>
> +enum commands_e {
Are you sure the name is unique enough / properly namespaced?
Same Q to all enums.
...
> + /*CTL_RESERVED = BIT(2),*/
Missing spaces?
Also, needs a comment why this is commented out.
...
> + CTL_BOOTLOADER = BIT(7)
Add trailing comma.
--
With Best Regards,
Andy Shevchenko
next parent reply other threads:[~2023-09-19 12:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20230919103815.16818-1-kabel@kernel.org>
[not found] ` <20230919103815.16818-3-kabel@kernel.org>
2023-09-19 12:29 ` Andy Shevchenko [this message]
[not found] ` <20230919171638.19bc1619@dellmb>
2023-09-19 18:27 ` [PATCH v2 2/7] platform: cznic: Add preliminary support for Turris Omnia MCU Andy Shevchenko
[not found] ` <20230920161953.6d952392@dellmb>
2023-09-20 14:47 ` Andy Shevchenko
[not found] ` <20230919103815.16818-5-kabel@kernel.org>
2023-09-22 16:28 ` [PATCH v2 4/7] platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup Marek Behún
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