Re: [PATCH v3 2/3] i2c: add support for HiSilicon I2C controller

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Mon, Mar 22, 2021 at 07:10:12PM +0800, Yicong Yang wrote:
> Add HiSilicon I2C controller driver for the Kunpeng SoC. It provides
> the access to the i2c busses, which connects to the eeprom, rtc, etc.
> 
> The driver works with IRQ mode, and supports basic I2C features and 10bit
> address. The DMA is not supported.

...

> +#include <linux/acpi.h>

Hadn't noticed how you are using this header.

> +#include <linux/bits.h>
> +#include <linux/bitfield.h>
> +#include <linux/completion.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>

Missed mod_devicetable.h.
Probably missed property.h, but not sure.

> +#include <linux/platform_device.h>

...

> +#define HISI_I2C_INT_ALL	0x1f

GENMASK() ?

...

> +#define HISI_I2C_INT_ERR	(HISI_I2C_INT_TRANS_ERR | \
> +				 HISI_I2C_INT_FIFO_ERR)

Either one line, or it will look better like
#define HISI_I2C_INT_ERR					\
	(HISI_I2C_INT_TRANS_ERR | HISI_I2C_INT_FIFO_ERR)

...

> +#define HISI_I2C_STD_SPEED_MODE		0x0
> +#define HISI_I2C_FAST_SPEED_MODE	0x1
> +#define HISI_I2C_HIGH_SPEED_MODE	0x2

Why not plain decimal numbers?

...

> +struct hisi_i2c_controller {
> +	struct device *dev;

> +	struct i2c_adapter adapter;

If you put this as a first member, the container_of() become a no-op for this.
But I dunno if it's used against this structure.

> +	void __iomem *iobase;
> +	int irq;
> +
> +	/* Intermediates for recording the transfer process */
> +	struct completion *completion;
> +	struct i2c_msg *msgs;
> +	int msg_num;
> +	int msg_tx_idx;
> +	int buf_tx_idx;
> +	int msg_rx_idx;
> +	int buf_rx_idx;
> +	u16 tar_addr;
> +	u32 xfer_err;
> +
> +	/* I2C bus configuration */
> +	u32 scl_fall_time;
> +	u32 scl_rise_time;
> +	u32 sda_hold_time;
> +	u64 clk_rate_khz;
> +	u32 bus_freq_hz;
> +	u32 spk_len;
> +};

...

> +	struct i2c_timings t;
> +
> +	i2c_parse_fw_timings(ctlr->dev, &t, true);
> +	ctlr->bus_freq_hz = t.bus_freq_hz;

> +	ctlr->scl_fall_time = t.scl_fall_ns;
> +	ctlr->scl_rise_time = t.scl_rise_ns;
> +	ctlr->sda_hold_time = t.sda_hold_ns;

Why not simply to have the timings structure embedded into hisi_i2c_controller
one?

...

> +	ctlr->dev = dev;

Would it make sense to assign aster getting IRQ resource...

> +	ctlr->iobase = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(ctlr->iobase))
> +		return PTR_ERR(ctlr->iobase);
> +
> +	ctlr->irq = platform_get_irq(pdev, 0);
> +	if (ctlr->irq < 0)
> +		return ctlr->irq;

...somewhere here?

> +	hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL);

...

> +	ctlr->clk_rate_khz = DIV_ROUND_UP_ULL(ctlr->clk_rate_khz, 1000);

HZ_PER_KHZ ?

-- 
With Best Regards,
Andy Shevchenko