> -----Original Message-----
> From: Quan Nguyen <q...@os.amperecomputing.com>
> Sent: Thursday, May 20, 2021 10:10 PM
> To: Ryan Chen <ryan_c...@aspeedtech.com>; Corey Minyard
> <miny...@acm.org>; Rob Herring <robh...@kernel.org>; Joel Stanley
> <j...@jms.id.au>; Andrew Jeffery <and...@aj.id.au>; Brendan Higgins
> <brendanhigg...@google.com>; Benjamin Herrenschmidt
> <b...@kernel.crashing.org>; Wolfram Sang <w...@kernel.org>; Philipp Zabel
> <p.za...@pengutronix.de>; openipmi-developer@lists.sourceforge.net;
> devicet...@vger.kernel.org; linux-arm-ker...@lists.infradead.org;
> linux-asp...@lists.ozlabs.org; linux-ker...@vger.kernel.org;
> linux-...@vger.kernel.org
> Cc: Open Source Submission <patc...@amperecomputing.com>; Thang Q .
> Nguyen <th...@os.amperecomputing.com>; Phong Vo
> <ph...@os.amperecomputing.com>; open...@lists.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....@lists.ozlabs.org> On
> Behalf
> >> Of Quan Nguyen
> >> Sent: Wednesday, May 19, 2021 3:50 PM
> >> To: Corey Minyard <miny...@acm.org>; Rob Herring
> >> <robh...@kernel.org>; Joel Stanley <j...@jms.id.au>; Andrew Jeffery
> >> <and...@aj.id.au>; Brendan Higgins <brendanhigg...@google.com>;
> >> Benjamin Herrenschmidt <b...@kernel.crashing.org>; Wolfram Sang
> >> <w...@kernel.org>; Philipp Zabel <p.za...@pengutronix.de>;
> >> openipmi-developer@lists.sourceforge.net;
> >> devicet...@vger.kernel.org; linux-arm-ker...@lists.infradead.org;
> >> linux-asp...@lists.ozlabs.org; linux-ker...@vger.kernel.org;
> >> linux-...@vger.kernel.org
> >> Cc: Open Source Submission <patc...@amperecomputing.com>; Thang Q .
> >> Nguyen <th...@os.amperecomputing.com>; Phong Vo
> >> <ph...@os.amperecomputing.com>; open...@lists.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 <q...@os.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.
>
> /* 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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