Hi, Geert, all,
On 28.06.2024 12:22, Geert Uytterhoeven wrote:
> Hi Claudiu,
>
> On Tue, Jun 25, 2024 at 2:14 PM Claudiu <claudiu.beznea@xxxxxxxxx> wrote:
>> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>>
>> Fast mode plus is available on most of the IP variants that RIIC driver
>> is working with. The exception is (according to HW manuals of the SoCs
>> where this IP is available) the Renesas RZ/A1H. For this, patch
>> introduces the struct riic_of_data::fast_mode_plus.
>>
>> Fast mode plus was tested on RZ/G3S, RZ/G2{L,UL,LC}, RZ/Five by
>> instantiating the RIIC frequency to 1MHz and issuing i2c reads on the
>> fast mode plus capable devices (and the i2c clock frequency was checked on
>> RZ/G3S).
>>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
>> --- a/drivers/i2c/busses/i2c-riic.c
>> +++ b/drivers/i2c/busses/i2c-riic.c
>> @@ -407,6 +413,9 @@ static int riic_init_hw(struct riic_dev *riic)
>> riic_writeb(riic, 0, RIIC_ICSER);
>> riic_writeb(riic, ICMR3_ACKWP | ICMR3_RDRFS, RIIC_ICMR3);
>>
>> + if (info->fast_mode_plus && t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ)
>> + riic_clear_set_bit(riic, 0, ICFER_FMPE, RIIC_ICFER);
>
> Unless FM+ is specified, RIIC_ICFER is never written to.
> Probably the register should always be initialized, also to make sure
> the FMPE bit is cleared when it was set by the boot loader, but FM+
> is not to be used.
Instead of clearing only this bit, what do you think about using
reset_control_reset() instead of reset_control_deassert() in riic_i2c_probe()?
HW manuals for all the devices listed in
Documentation/devicetree/bindings/i2c/renesas,riic.yaml specifies that
ICFER_FMPE register is initialized with a default value by reset. All the
other registers are initialized with default values at reset (according to
HW manuals). I've checked it on RZ/G3S and it behaves like this.
With this:
diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index ba969ad5f015..150e7841f178 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -457,7 +457,7 @@ static int riic_i2c_probe(struct platform_device *pdev)
return dev_err_probe(dev, PTR_ERR(riic->rstc),
"Error: missing reset ctrl\n");
- ret = reset_control_deassert(riic->rstc);
+ ret = reset_control_reset(riic->rstc);
if (ret)
return ret;
I've did basic tests (i2cdetect + i2cget with FM+ frequency) on RZ/G2{L,
LC, UL}, RZ/V2L and all was good.
Thank you,
Claudiu Beznea
>
>
>> +
>> riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);
>>
>> pm_runtime_mark_last_busy(dev);
>
> Gr{oetje,eeting}s,
>
> Geert
>
