Re: [PATCH v5 02/11] platform: cznic: Add preliminary support for Turris Omnia MCU

[Andy Shevchenko <andy.shevchenko@gmail.com>]

Sat, Mar 23, 2024 at 05:43:50PM +0100, Marek Behún kirjoitti:
> Add the basic skeleton for a new platform driver for the microcontroller
> found on the Turris Omnia board.

...

> +++ b/drivers/platform/cznic/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
> +turris-omnia-mcu-objs		:= turris-omnia-mcu-base.o

'objs' is for user space. You need to use 'y'. Same applies to the entire
series.

...

+ array_size.h
+ bits.h

> +#include <linux/device.h>
> +#include <linux/hex.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/turris-omnia-mcu-interface.h>
> +#include <linux/types.h>

+ string.h

> +#include <linux/sysfs.h>

...

> +	err = omnia_cmd_read(mcu->client, bootloader ? CMD_GET_FW_VERSION_BOOT :
> +						       CMD_GET_FW_VERSION_APP,
> +			     reply, sizeof(reply));

Wouldn't be better to have a logical split?

	err = omnia_cmd_read(mcu->client,
			     bootloader ? CMD_GET_FW_VERSION_BOOT : CMD_GET_FW_VERSION_APP,
			     reply, sizeof(reply));

?

...

> +	struct omnia_mcu *mcu = i2c_get_clientdata(to_i2c_client(dev));

What's wrong with dev_get_drvdata()?

...

> +static ssize_t fw_features_show(struct device *dev, struct device_attribute *a,
> +				char *buf)

One line?

...

> +	struct omnia_mcu *mcu = i2c_get_clientdata(to_i2c_client(dev));

Use direct call (see above). Same applies to all such constructions in your
code.

...

> +static const struct attribute_group omnia_mcu_base_group = {
> +	.attrs = omnia_mcu_base_attrs,
> +	.is_visible = omnia_mcu_base_attrs_visible,
> +};
> +
> +static const struct attribute_group *omnia_mcu_groups[] = {
> +	&omnia_mcu_base_group,
> +	NULL
> +};

__ATTRIBUTE_GROUPS()

...

> +static struct i2c_driver omnia_mcu_driver = {
> +	.probe		= omnia_mcu_probe,
> +	.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 __TURRIS_OMNIA_MCU_H
> +#define __TURRIS_OMNIA_MCU_H

+ array_size.h

> +#include <linux/i2c.h>
> +#include <linux/if_ether.h>
> +#include <linux/types.h>
> +#include <asm/byteorder.h>

...

> +static inline int omnia_cmd_read(const struct i2c_client *client, u8 cmd,
> +				 void *reply, unsigned int len)
> +{

Why is this in the header?

> +	struct i2c_msg msgs[2];
> +	int ret;
> +
> +	msgs[0].addr = client->addr;
> +	msgs[0].flags = 0;
> +	msgs[0].len = 1;
> +	msgs[0].buf = &cmd;
> +	msgs[1].addr = client->addr;
> +	msgs[1].flags = I2C_M_RD;
> +	msgs[1].len = len;
> +	msgs[1].buf = reply;
> +
> +	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
> +	if (ret < 0)
> +		return ret;
> +	if (ret != ARRAY_SIZE(msgs))
> +		return -EIO;
> +
> +	return 0;
> +}

...

> +#ifndef __TURRIS_OMNIA_MCU_INTERFACE_H
> +#define __TURRIS_OMNIA_MCU_INTERFACE_H
> +
> +#include <linux/bits.h>

+ bitfield.h

> +#endif /* __TURRIS_OMNIA_MCU_INTERFACE_H */

-- 
With Best Regards,
Andy Shevchenko