Re: [PATCH v1 1/4] i2c: designware: Split out i2c_dw_validate_speed() helper

[Jarkko Nikula <jarkko.nikula@linux.intel.com>]

On 5/11/20 4:42 PM, Andy Shevchenko wrote:
> On Mon, May 11, 2020 at 04:11:57PM +0300, Jarkko Nikula wrote:
>> On 5/7/20 4:51 PM, Andy Shevchenko wrote:
>>> In order to export array supported speed for wider use,
>>> split out them along with i2c_dw_validate_speed() helper.
>>>
>>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>>> ---
>>>    drivers/i2c/busses/i2c-designware-core.h    | 31 +++++++++++++++++++++
>>>    drivers/i2c/busses/i2c-designware-platdrv.c | 29 ++++---------------
>>>    2 files changed, 36 insertions(+), 24 deletions(-)
>>>
>>> diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
>>> index 1674caf277451..626959573f894 100644
>>> --- a/drivers/i2c/busses/i2c-designware-core.h
>>> +++ b/drivers/i2c/busses/i2c-designware-core.h
>>> @@ -9,6 +9,7 @@
>>>     * Copyright (C) 2009 Provigent Ltd.
>>>     */
>>> +#include <linux/errno.h>
>>>    #include <linux/i2c.h>
>>>    #define DW_IC_DEFAULT_FUNCTIONALITY (I2C_FUNC_I2C |			\
>>> @@ -351,3 +352,33 @@ extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
>>>    #else
>>>    static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; }
>>>    #endif
>>> +
>>> +static const u32 i2c_dw_supported_speeds[] = {
>>> +	I2C_MAX_HIGH_SPEED_MODE_FREQ,
>>> +	I2C_MAX_FAST_MODE_PLUS_FREQ,
>>> +	I2C_MAX_FAST_MODE_FREQ,
>>> +	I2C_MAX_STANDARD_MODE_FREQ,
>>> +};
>>> +
>>> +static inline int i2c_dw_validate_speed(struct dw_i2c_dev *dev)
>>> +{
>>> +	struct i2c_timings *t = &dev->timings;
>>> +	unsigned int i;
>>> +
>>> +	/*
>>> +	 * Only standard mode at 100kHz, fast mode at 400kHz,
>>> +	 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
>>> +	 */
>>> +	for (i = 0; i < ARRAY_SIZE(i2c_dw_supported_speeds); i++) {
>>> +		if (t->bus_freq_hz == i2c_dw_supported_speeds[i])
>>> +			break;
>>> +	}
>>> +	if (i == ARRAY_SIZE(i2c_dw_supported_speeds)) {
>>> +		dev_err(dev->dev,
>>> +			"%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
>>> +			t->bus_freq_hz);
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>
>> This header is included by every i2c-designware-*.c file and this inline
>> function is not tiny. Would it be better to have this in
>> i2c-designware-common.c instead?
> 
> Yes, but then we will need to export i2c_dw_supported_speeds as well as its
> array size.
> 
Would that not be needed if you move ACPI parts also into 
i2c-designware-common.c?

-- 
Jarkko