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Message-ID: <b39c7434-4926-4bb1-88d8-59c6464f3fb1@os.amperecomputing.com>
Date: Fri, 28 May 2021 08:00:09 +0700
From: Quan Nguyen <quan@...amperecomputing.com>
To: Ryan Chen <ryan_chen@...eedtech.com>,
Corey Minyard <minyard@....org>,
Rob Herring <robh+dt@...nel.org>,
Joel Stanley <joel@....id.au>,
Andrew Jeffery <andrew@...id.au>,
Brendan Higgins <brendanhiggins@...gle.com>,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Wolfram Sang <wsa@...nel.org>,
Philipp Zabel <p.zabel@...gutronix.de>,
"openipmi-developer@...ts.sourceforge.net"
<openipmi-developer@...ts.sourceforge.net>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-aspeed@...ts.ozlabs.org" <linux-aspeed@...ts.ozlabs.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>
Cc: Open Source Submission <patches@...erecomputing.com>,
"Thang Q . Nguyen" <thang@...amperecomputing.com>,
Phong Vo <phong@...amperecomputing.com>,
"openbmc@...ts.ozlabs.org" <openbmc@...ts.ozlabs.org>
Subject: Re: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
On 21/05/2021 13:09, Ryan Chen wrote:
>> -----Original Message-----
>> From: Quan Nguyen <quan@...amperecomputing.com>
>> Sent: Thursday, May 20, 2021 10:10 PM
>> To: Ryan Chen <ryan_chen@...eedtech.com>; Corey Minyard
>> <minyard@....org>; Rob Herring <robh+dt@...nel.org>; Joel Stanley
>> <joel@....id.au>; Andrew Jeffery <andrew@...id.au>; Brendan Higgins
>> <brendanhiggins@...gle.com>; Benjamin Herrenschmidt
>> <benh@...nel.crashing.org>; Wolfram Sang <wsa@...nel.org>; Philipp Zabel
>> <p.zabel@...gutronix.de>; openipmi-developer@...ts.sourceforge.net;
>> devicetree@...r.kernel.org; linux-arm-kernel@...ts.infradead.org;
>> linux-aspeed@...ts.ozlabs.org; linux-kernel@...r.kernel.org;
>> linux-i2c@...r.kernel.org
>> Cc: Open Source Submission <patches@...erecomputing.com>; Thang Q .
>> Nguyen <thang@...amperecomputing.com>; Phong Vo
>> <phong@...amperecomputing.com>; openbmc@...ts.ozlabs.org
>> Subject: Re: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
>>
>> On 20/05/2021 18:06, Ryan Chen wrote:
>>>> -----Original Message-----
>>>> From: openbmc
>>>> <openbmc-bounces+ryan_chen=aspeedtech.com@...ts.ozlabs.org> On
>> Behalf
>>>> Of Quan Nguyen
>>>> Sent: Wednesday, May 19, 2021 3:50 PM
>>>> To: Corey Minyard <minyard@....org>; Rob Herring
>>>> <robh+dt@...nel.org>; Joel Stanley <joel@....id.au>; Andrew Jeffery
>>>> <andrew@...id.au>; Brendan Higgins <brendanhiggins@...gle.com>;
>>>> Benjamin Herrenschmidt <benh@...nel.crashing.org>; Wolfram Sang
>>>> <wsa@...nel.org>; Philipp Zabel <p.zabel@...gutronix.de>;
>>>> openipmi-developer@...ts.sourceforge.net;
>>>> devicetree@...r.kernel.org; linux-arm-kernel@...ts.infradead.org;
>>>> linux-aspeed@...ts.ozlabs.org; linux-kernel@...r.kernel.org;
>>>> linux-i2c@...r.kernel.org
>>>> Cc: Open Source Submission <patches@...erecomputing.com>; Thang Q .
>>>> Nguyen <thang@...amperecomputing.com>; Phong Vo
>>>> <phong@...amperecomputing.com>; openbmc@...ts.ozlabs.org
>>>> Subject: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy()
>>>>
>>>> Slave i2c device on AST2500 received a lot of slave irq while it is
>>>> busy processing the response. To handle this case, adds and exports
>>>> aspeed_set_slave_busy() for controller to temporary stop slave irq
>>>> while slave is handling the response, and re-enable them again when the
>> response is ready.
>>>>
>>>> Signed-off-by: Quan Nguyen <quan@...amperecomputing.com>
>>>> ---
>>>> v3:
>>>> + First introduce in v3 [Quan]
>>>>
>>>> drivers/i2c/busses/i2c-aspeed.c | 20 ++++++++++++++++++++
>>>> 1 file changed, 20 insertions(+)
>>>>
>>>> diff --git a/drivers/i2c/busses/i2c-aspeed.c
>>>> b/drivers/i2c/busses/i2c-aspeed.c index b2e9c8f0ddf7..9926d04831a2
>>>> 100644
>>>> --- a/drivers/i2c/busses/i2c-aspeed.c
>>>> +++ b/drivers/i2c/busses/i2c-aspeed.c
>>>> @@ -944,6 +944,26 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus
>>>> *bus,
>>>> return 0;
>>>> }
>>>>
>>>> +#if IS_ENABLED(CONFIG_I2C_SLAVE)
>>>> +void aspeed_set_slave_busy(struct i2c_adapter *adap, bool busy) {
>>>> + struct aspeed_i2c_bus *bus = i2c_get_adapdata(adap);
>>>> + unsigned long current_mask, flags;
>>>> +
>>>> + spin_lock_irqsave(&bus->lock, flags);
>>>> +
>>>> + current_mask = readl(bus->base + ASPEED_I2C_INTR_CTRL_REG);
>>>> + if (busy)
>>>> + current_mask &= ~(ASPEED_I2CD_INTR_RX_DONE |
>>>> ASPEED_I2CD_INTR_SLAVE_MATCH);
>>>> + else
>>>> + current_mask |= ASPEED_I2CD_INTR_RX_DONE |
>>>> ASPEED_I2CD_INTR_SLAVE_MATCH;
>>>> + writel(current_mask, bus->base + ASPEED_I2C_INTR_CTRL_REG);
>>>> +
>>>> + spin_unlock_irqrestore(&bus->lock, flags); }
>>>> +EXPORT_SYMBOL_GPL(aspeed_set_slave_busy);
>>>> +#endif
>>>> +
>>>> static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus) {
>>>> struct platform_device *pdev = to_platform_device(bus->dev);
>>>> --
>>>> 2.28.0
>>>
>>> Hello,
>>> The better idea is use disable i2c slave mode.
>>> Due to if i2c controller running in slave will get slave match, and latch the
>> SCL.
>>> Until cpu clear interrupt status.
>>> Ryan
>>>
>> Thanks Ryan,
>>
>> Do you mean to enable/disable slave function as per example code below ?
> Yes. it is.
Dear Ryan,
This solution looks good. I'll switch to use this way in next version.
Thanks for the suggestion.
- Quan
>>
>> /* Turn on slave mode. */
>> func_ctrl_reg_val = readl(bus->base +
>> ASPEED_I2C_FUN_CTRL_REG);
>> func_ctrl_reg_val |= ASPEED_I2CD_SLAVE_EN;
>> writel(func_ctrl_reg_val, bus->base +
>> ASPEED_I2C_FUN_CTRL_REG);
>>
>> Will try this idea.
>> - Quan
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