Messages in this thread | | | From | Ryan Chen <> | Subject | RE: [PATCH v3 5/7] i2c: aspeed: Add aspeed_set_slave_busy() | Date | Fri, 21 May 2021 06:09:57 +0000 |
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> -----Original Message----- > From: Quan Nguyen <quan@os.amperecomputing.com> > Sent: Thursday, May 20, 2021 10:10 PM > To: Ryan Chen <ryan_chen@aspeedtech.com>; Corey Minyard > <minyard@acm.org>; Rob Herring <robh+dt@kernel.org>; Joel Stanley > <joel@jms.id.au>; Andrew Jeffery <andrew@aj.id.au>; Brendan Higgins > <brendanhiggins@google.com>; Benjamin Herrenschmidt > <benh@kernel.crashing.org>; Wolfram Sang <wsa@kernel.org>; Philipp Zabel > <p.zabel@pengutronix.de>; openipmi-developer@lists.sourceforge.net; > devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org; > linux-aspeed@lists.ozlabs.org; linux-kernel@vger.kernel.org; > linux-i2c@vger.kernel.org > Cc: Open Source Submission <patches@amperecomputing.com>; Thang Q . > Nguyen <thang@os.amperecomputing.com>; Phong Vo > <phong@os.amperecomputing.com>; openbmc@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.com@lists.ozlabs.org> On > Behalf > >> Of Quan Nguyen > >> Sent: Wednesday, May 19, 2021 3:50 PM > >> To: Corey Minyard <minyard@acm.org>; Rob Herring > >> <robh+dt@kernel.org>; Joel Stanley <joel@jms.id.au>; Andrew Jeffery > >> <andrew@aj.id.au>; Brendan Higgins <brendanhiggins@google.com>; > >> Benjamin Herrenschmidt <benh@kernel.crashing.org>; Wolfram Sang > >> <wsa@kernel.org>; Philipp Zabel <p.zabel@pengutronix.de>; > >> openipmi-developer@lists.sourceforge.net; > >> devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org; > >> linux-aspeed@lists.ozlabs.org; linux-kernel@vger.kernel.org; > >> linux-i2c@vger.kernel.org > >> Cc: Open Source Submission <patches@amperecomputing.com>; Thang Q . > >> Nguyen <thang@os.amperecomputing.com>; Phong Vo > >> <phong@os.amperecomputing.com>; openbmc@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 <quan@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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