From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> To: Wolfram Sang <wsa@the-dreams.de>, Brendan Higgins <brendanhiggins@google.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>, linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Jarkko Nikula <jarkko.nikula@linux.intel.com>, James Feist <james.feist@linux.intel.com>, Vernon Mauery <vernon.mauery@linux.intel.com>, Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> Subject: [PATCH] i2c: aspeed: Add multi-master use case support Date: Wed, 16 Jan 2019 11:39:58 -0800 [thread overview] Message-ID: <20190116193958.6049-1-jae.hyun.yoo@linux.intel.com> (raw) In multi-master environment, this driver's master cannot know exactly when a peer master sends data to this driver's slave so cases can be happened that this master tries sending data through the master_xfer function but slave data from a peer master is still being processed or slave xfer is started by a peer immediately after it queues a master command. To support multi-master use cases properly, this H/W provides arbitration in physical level and it provides priority based command handling too to avoid conflicts in multi-master environment, means that if a master and a slave events happen at the same time, H/W will handle a higher priority event first and a pending event will be handled when bus comes back to the idle state. To support this H/W feature properly, this patch adds the 'pending' state of master and its handling code so that the pending master xfer can be continued after slave operation properly. Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> --- drivers/i2c/busses/i2c-aspeed.c | 118 +++++++++++++++++++++++++------- 1 file changed, 92 insertions(+), 26 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index 8dc9161ced38..9253ebccb008 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -117,6 +117,7 @@ enum aspeed_i2c_master_state { ASPEED_I2C_MASTER_INACTIVE, + ASPEED_I2C_MASTER_PENDING, ASPEED_I2C_MASTER_START, ASPEED_I2C_MASTER_TX_FIRST, ASPEED_I2C_MASTER_TX, @@ -126,12 +127,13 @@ enum aspeed_i2c_master_state { }; enum aspeed_i2c_slave_state { - ASPEED_I2C_SLAVE_STOP, + ASPEED_I2C_SLAVE_INACTIVE, ASPEED_I2C_SLAVE_START, ASPEED_I2C_SLAVE_READ_REQUESTED, ASPEED_I2C_SLAVE_READ_PROCESSED, ASPEED_I2C_SLAVE_WRITE_REQUESTED, ASPEED_I2C_SLAVE_WRITE_RECEIVED, + ASPEED_I2C_SLAVE_STOP, }; struct aspeed_i2c_bus { @@ -156,6 +158,8 @@ struct aspeed_i2c_bus { int cmd_err; /* Protected only by i2c_lock_bus */ int master_xfer_result; + /* Multi-master */ + bool multi_master; #if IS_ENABLED(CONFIG_I2C_SLAVE) struct i2c_client *slave; enum aspeed_i2c_slave_state slave_state; @@ -251,7 +255,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) } /* Slave is not currently active, irq was for someone else. */ - if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) + if (bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE) return irq_handled; dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", @@ -277,16 +281,15 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; bus->slave_state = ASPEED_I2C_SLAVE_STOP; } - if (irq_status & ASPEED_I2CD_INTR_TX_NAK) { + if (irq_status & ASPEED_I2CD_INTR_TX_NAK && + bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) { irq_handled |= ASPEED_I2CD_INTR_TX_NAK; bus->slave_state = ASPEED_I2C_SLAVE_STOP; } - if (irq_status & ASPEED_I2CD_INTR_TX_ACK) - irq_handled |= ASPEED_I2CD_INTR_TX_ACK; switch (bus->slave_state) { case ASPEED_I2C_SLAVE_READ_REQUESTED: - if (irq_status & ASPEED_I2CD_INTR_TX_ACK) + if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_ACK)) dev_err(bus->dev, "Unexpected ACK on read request.\n"); bus->slave_state = ASPEED_I2C_SLAVE_READ_PROCESSED; i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value); @@ -294,9 +297,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); break; case ASPEED_I2C_SLAVE_READ_PROCESSED: - if (!(irq_status & ASPEED_I2CD_INTR_TX_ACK)) + if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { dev_err(bus->dev, "Expected ACK after processed read.\n"); + break; + } + irq_handled |= ASPEED_I2CD_INTR_TX_ACK; i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value); writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG); writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); @@ -310,10 +316,15 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) break; case ASPEED_I2C_SLAVE_STOP: i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; + break; + case ASPEED_I2C_SLAVE_START: + /* Slave was just started. Waiting for the next event. */; break; default: - dev_err(bus->dev, "unhandled slave_state: %d\n", + dev_err(bus->dev, "unknown slave_state: %d\n", bus->slave_state); + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; break; } @@ -329,6 +340,17 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) u8 slave_addr = i2c_8bit_addr_from_msg(msg); bus->master_state = ASPEED_I2C_MASTER_START; + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + /* + * If it's requested in the middle of a slave session, set the master + * state to 'pending' then H/W will continue handling this master + * command when the bus comes back to the idle state. + */ + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) + bus->master_state = ASPEED_I2C_MASTER_PENDING; +#endif /* CONFIG_I2C_SLAVE */ + bus->buf_index = 0; if (msg->flags & I2C_M_RD) { @@ -384,10 +406,6 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) bus->master_state = ASPEED_I2C_MASTER_INACTIVE; irq_handled |= ASPEED_I2CD_INTR_BUS_RECOVER_DONE; goto out_complete; - } else { - /* Master is not currently active, irq was for someone else. */ - if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE) - goto out_no_complete; } /* @@ -399,11 +417,32 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) if (ret) { dev_dbg(bus->dev, "received error interrupt: 0x%08x\n", irq_status); - bus->cmd_err = ret; - bus->master_state = ASPEED_I2C_MASTER_INACTIVE; irq_handled |= (irq_status & ASPEED_I2CD_INTR_MASTER_ERRORS); - goto out_complete; + if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) { + bus->cmd_err = ret; + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + goto out_complete; + } + } + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + /* + * A pending master command will be started by H/W when the bus comes + * back to idle state after completing a slave operation so change the + * master state from 'pending' to 'start' at here if slave is inactive. + */ + if (bus->master_state == ASPEED_I2C_MASTER_PENDING) { + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) + goto out_no_complete; + + bus->master_state = ASPEED_I2C_MASTER_START; } +#endif /* CONFIG_I2C_SLAVE */ + + /* Master is not currently active, irq was for someone else. */ + if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE || + bus->master_state == ASPEED_I2C_MASTER_PENDING) + goto out_no_complete; /* We are in an invalid state; reset bus to a known state. */ if (!bus->msgs) { @@ -423,6 +462,20 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) * then update the state and handle the new state below. */ if (bus->master_state == ASPEED_I2C_MASTER_START) { +#if IS_ENABLED(CONFIG_I2C_SLAVE) + /* + * If a peer master starts a xfer immediately after it queues a + * master command, change its state to 'pending' then H/W will + * continue the queued master xfer just after completing the + * slave mode session. + */ + if (unlikely(irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH)) { + bus->master_state = ASPEED_I2C_MASTER_PENDING; + dev_dbg(bus->dev, + "master goes pending due to a slave start\n"); + goto out_no_complete; + } +#endif /* CONFIG_I2C_SLAVE */ if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_NAK))) { bus->cmd_err = -ENXIO; @@ -566,7 +619,8 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) * interrupt bits. Each case needs to be handled using corresponding * handlers depending on the current state. */ - if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) { + if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE && + bus->master_state != ASPEED_I2C_MASTER_PENDING) { irq_handled = aspeed_i2c_master_irq(bus, irq_remaining); irq_remaining &= ~irq_handled; if (irq_remaining) @@ -601,15 +655,15 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, { struct aspeed_i2c_bus *bus = i2c_get_adapdata(adap); unsigned long time_left, flags; - int ret = 0; + int ret; spin_lock_irqsave(&bus->lock, flags); bus->cmd_err = 0; - /* If bus is busy, attempt recovery. We assume a single master - * environment. - */ - if (readl(bus->base + ASPEED_I2C_CMD_REG) & ASPEED_I2CD_BUS_BUSY_STS) { + /* If bus is busy in a single master environment, attempt recovery. */ + if (!bus->multi_master && + (readl(bus->base + ASPEED_I2C_CMD_REG) & + ASPEED_I2CD_BUS_BUSY_STS)) { spin_unlock_irqrestore(&bus->lock, flags); ret = aspeed_i2c_recover_bus(bus); if (ret) @@ -629,10 +683,20 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, time_left = wait_for_completion_timeout(&bus->cmd_complete, bus->adap.timeout); - if (time_left == 0) + if (time_left == 0) { + /* + * If timed out and bus is still busy in a multi master + * environment, attempt recovery at here. + */ + if (bus->multi_master && + (readl(bus->base + ASPEED_I2C_CMD_REG) & + ASPEED_I2CD_BUS_BUSY_STS)) + ret = aspeed_i2c_recover_bus(bus); + return -ETIMEDOUT; - else - return bus->master_xfer_result; + } + + return bus->master_xfer_result; } static u32 aspeed_i2c_functionality(struct i2c_adapter *adap) @@ -672,7 +736,7 @@ static int aspeed_i2c_reg_slave(struct i2c_client *client) __aspeed_i2c_reg_slave(bus, client->addr); bus->slave = client; - bus->slave_state = ASPEED_I2C_SLAVE_STOP; + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; spin_unlock_irqrestore(&bus->lock, flags); return 0; @@ -827,7 +891,9 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus, if (ret < 0) return ret; - if (!of_property_read_bool(pdev->dev.of_node, "multi-master")) + if (of_property_read_bool(pdev->dev.of_node, "multi-master")) + bus->multi_master = true; + else fun_ctrl_reg |= ASPEED_I2CD_MULTI_MASTER_DIS; /* Enable Master Mode */ -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> To: Wolfram Sang <wsa@the-dreams.de>, Brendan Higgins <brendanhiggins@google.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Joel Stanley <joel@jms.id.au>, Andrew Jeffery <andrew@aj.id.au>, linux-i2c@vger.kernel.org, openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Vernon Mauery <vernon.mauery@linux.intel.com>, Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>, Jarkko Nikula <jarkko.nikula@linux.intel.com>, James Feist <james.feist@linux.intel.com> Subject: [PATCH] i2c: aspeed: Add multi-master use case support Date: Wed, 16 Jan 2019 11:39:58 -0800 [thread overview] Message-ID: <20190116193958.6049-1-jae.hyun.yoo@linux.intel.com> (raw) In multi-master environment, this driver's master cannot know exactly when a peer master sends data to this driver's slave so cases can be happened that this master tries sending data through the master_xfer function but slave data from a peer master is still being processed or slave xfer is started by a peer immediately after it queues a master command. To support multi-master use cases properly, this H/W provides arbitration in physical level and it provides priority based command handling too to avoid conflicts in multi-master environment, means that if a master and a slave events happen at the same time, H/W will handle a higher priority event first and a pending event will be handled when bus comes back to the idle state. To support this H/W feature properly, this patch adds the 'pending' state of master and its handling code so that the pending master xfer can be continued after slave operation properly. Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> --- drivers/i2c/busses/i2c-aspeed.c | 118 +++++++++++++++++++++++++------- 1 file changed, 92 insertions(+), 26 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index 8dc9161ced38..9253ebccb008 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -117,6 +117,7 @@ enum aspeed_i2c_master_state { ASPEED_I2C_MASTER_INACTIVE, + ASPEED_I2C_MASTER_PENDING, ASPEED_I2C_MASTER_START, ASPEED_I2C_MASTER_TX_FIRST, ASPEED_I2C_MASTER_TX, @@ -126,12 +127,13 @@ enum aspeed_i2c_master_state { }; enum aspeed_i2c_slave_state { - ASPEED_I2C_SLAVE_STOP, + ASPEED_I2C_SLAVE_INACTIVE, ASPEED_I2C_SLAVE_START, ASPEED_I2C_SLAVE_READ_REQUESTED, ASPEED_I2C_SLAVE_READ_PROCESSED, ASPEED_I2C_SLAVE_WRITE_REQUESTED, ASPEED_I2C_SLAVE_WRITE_RECEIVED, + ASPEED_I2C_SLAVE_STOP, }; struct aspeed_i2c_bus { @@ -156,6 +158,8 @@ struct aspeed_i2c_bus { int cmd_err; /* Protected only by i2c_lock_bus */ int master_xfer_result; + /* Multi-master */ + bool multi_master; #if IS_ENABLED(CONFIG_I2C_SLAVE) struct i2c_client *slave; enum aspeed_i2c_slave_state slave_state; @@ -251,7 +255,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) } /* Slave is not currently active, irq was for someone else. */ - if (bus->slave_state == ASPEED_I2C_SLAVE_STOP) + if (bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE) return irq_handled; dev_dbg(bus->dev, "slave irq status 0x%08x, cmd 0x%08x\n", @@ -277,16 +281,15 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; bus->slave_state = ASPEED_I2C_SLAVE_STOP; } - if (irq_status & ASPEED_I2CD_INTR_TX_NAK) { + if (irq_status & ASPEED_I2CD_INTR_TX_NAK && + bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) { irq_handled |= ASPEED_I2CD_INTR_TX_NAK; bus->slave_state = ASPEED_I2C_SLAVE_STOP; } - if (irq_status & ASPEED_I2CD_INTR_TX_ACK) - irq_handled |= ASPEED_I2CD_INTR_TX_ACK; switch (bus->slave_state) { case ASPEED_I2C_SLAVE_READ_REQUESTED: - if (irq_status & ASPEED_I2CD_INTR_TX_ACK) + if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_ACK)) dev_err(bus->dev, "Unexpected ACK on read request.\n"); bus->slave_state = ASPEED_I2C_SLAVE_READ_PROCESSED; i2c_slave_event(slave, I2C_SLAVE_READ_REQUESTED, &value); @@ -294,9 +297,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); break; case ASPEED_I2C_SLAVE_READ_PROCESSED: - if (!(irq_status & ASPEED_I2CD_INTR_TX_ACK)) + if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { dev_err(bus->dev, "Expected ACK after processed read.\n"); + break; + } + irq_handled |= ASPEED_I2CD_INTR_TX_ACK; i2c_slave_event(slave, I2C_SLAVE_READ_PROCESSED, &value); writel(value, bus->base + ASPEED_I2C_BYTE_BUF_REG); writel(ASPEED_I2CD_S_TX_CMD, bus->base + ASPEED_I2C_CMD_REG); @@ -310,10 +316,15 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) break; case ASPEED_I2C_SLAVE_STOP: i2c_slave_event(slave, I2C_SLAVE_STOP, &value); + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; + break; + case ASPEED_I2C_SLAVE_START: + /* Slave was just started. Waiting for the next event. */; break; default: - dev_err(bus->dev, "unhandled slave_state: %d\n", + dev_err(bus->dev, "unknown slave_state: %d\n", bus->slave_state); + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; break; } @@ -329,6 +340,17 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) u8 slave_addr = i2c_8bit_addr_from_msg(msg); bus->master_state = ASPEED_I2C_MASTER_START; + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + /* + * If it's requested in the middle of a slave session, set the master + * state to 'pending' then H/W will continue handling this master + * command when the bus comes back to the idle state. + */ + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) + bus->master_state = ASPEED_I2C_MASTER_PENDING; +#endif /* CONFIG_I2C_SLAVE */ + bus->buf_index = 0; if (msg->flags & I2C_M_RD) { @@ -384,10 +406,6 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) bus->master_state = ASPEED_I2C_MASTER_INACTIVE; irq_handled |= ASPEED_I2CD_INTR_BUS_RECOVER_DONE; goto out_complete; - } else { - /* Master is not currently active, irq was for someone else. */ - if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE) - goto out_no_complete; } /* @@ -399,11 +417,32 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) if (ret) { dev_dbg(bus->dev, "received error interrupt: 0x%08x\n", irq_status); - bus->cmd_err = ret; - bus->master_state = ASPEED_I2C_MASTER_INACTIVE; irq_handled |= (irq_status & ASPEED_I2CD_INTR_MASTER_ERRORS); - goto out_complete; + if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) { + bus->cmd_err = ret; + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + goto out_complete; + } + } + +#if IS_ENABLED(CONFIG_I2C_SLAVE) + /* + * A pending master command will be started by H/W when the bus comes + * back to idle state after completing a slave operation so change the + * master state from 'pending' to 'start' at here if slave is inactive. + */ + if (bus->master_state == ASPEED_I2C_MASTER_PENDING) { + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) + goto out_no_complete; + + bus->master_state = ASPEED_I2C_MASTER_START; } +#endif /* CONFIG_I2C_SLAVE */ + + /* Master is not currently active, irq was for someone else. */ + if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE || + bus->master_state == ASPEED_I2C_MASTER_PENDING) + goto out_no_complete; /* We are in an invalid state; reset bus to a known state. */ if (!bus->msgs) { @@ -423,6 +462,20 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) * then update the state and handle the new state below. */ if (bus->master_state == ASPEED_I2C_MASTER_START) { +#if IS_ENABLED(CONFIG_I2C_SLAVE) + /* + * If a peer master starts a xfer immediately after it queues a + * master command, change its state to 'pending' then H/W will + * continue the queued master xfer just after completing the + * slave mode session. + */ + if (unlikely(irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH)) { + bus->master_state = ASPEED_I2C_MASTER_PENDING; + dev_dbg(bus->dev, + "master goes pending due to a slave start\n"); + goto out_no_complete; + } +#endif /* CONFIG_I2C_SLAVE */ if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) { if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_NAK))) { bus->cmd_err = -ENXIO; @@ -566,7 +619,8 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) * interrupt bits. Each case needs to be handled using corresponding * handlers depending on the current state. */ - if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE) { + if (bus->master_state != ASPEED_I2C_MASTER_INACTIVE && + bus->master_state != ASPEED_I2C_MASTER_PENDING) { irq_handled = aspeed_i2c_master_irq(bus, irq_remaining); irq_remaining &= ~irq_handled; if (irq_remaining) @@ -601,15 +655,15 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, { struct aspeed_i2c_bus *bus = i2c_get_adapdata(adap); unsigned long time_left, flags; - int ret = 0; + int ret; spin_lock_irqsave(&bus->lock, flags); bus->cmd_err = 0; - /* If bus is busy, attempt recovery. We assume a single master - * environment. - */ - if (readl(bus->base + ASPEED_I2C_CMD_REG) & ASPEED_I2CD_BUS_BUSY_STS) { + /* If bus is busy in a single master environment, attempt recovery. */ + if (!bus->multi_master && + (readl(bus->base + ASPEED_I2C_CMD_REG) & + ASPEED_I2CD_BUS_BUSY_STS)) { spin_unlock_irqrestore(&bus->lock, flags); ret = aspeed_i2c_recover_bus(bus); if (ret) @@ -629,10 +683,20 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, time_left = wait_for_completion_timeout(&bus->cmd_complete, bus->adap.timeout); - if (time_left == 0) + if (time_left == 0) { + /* + * If timed out and bus is still busy in a multi master + * environment, attempt recovery at here. + */ + if (bus->multi_master && + (readl(bus->base + ASPEED_I2C_CMD_REG) & + ASPEED_I2CD_BUS_BUSY_STS)) + ret = aspeed_i2c_recover_bus(bus); + return -ETIMEDOUT; - else - return bus->master_xfer_result; + } + + return bus->master_xfer_result; } static u32 aspeed_i2c_functionality(struct i2c_adapter *adap) @@ -672,7 +736,7 @@ static int aspeed_i2c_reg_slave(struct i2c_client *client) __aspeed_i2c_reg_slave(bus, client->addr); bus->slave = client; - bus->slave_state = ASPEED_I2C_SLAVE_STOP; + bus->slave_state = ASPEED_I2C_SLAVE_INACTIVE; spin_unlock_irqrestore(&bus->lock, flags); return 0; @@ -827,7 +891,9 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus, if (ret < 0) return ret; - if (!of_property_read_bool(pdev->dev.of_node, "multi-master")) + if (of_property_read_bool(pdev->dev.of_node, "multi-master")) + bus->multi_master = true; + else fun_ctrl_reg |= ASPEED_I2CD_MULTI_MASTER_DIS; /* Enable Master Mode */ -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-01-16 19:40 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-01-16 19:39 Jae Hyun Yoo [this message] 2019-01-16 19:39 ` [PATCH] i2c: aspeed: Add multi-master use case support Jae Hyun Yoo 2019-01-31 18:20 ` Jae Hyun Yoo 2019-01-31 18:20 ` Jae Hyun Yoo 2019-02-07 19:48 ` Brendan Higgins 2019-02-07 19:48 ` Brendan Higgins 2019-02-07 19:48 ` Brendan Higgins 2019-02-08 21:48 ` Wolfram Sang 2019-02-08 21:48 ` Wolfram Sang 2019-02-11 18:09 ` Jae Hyun Yoo 2019-02-11 18:09 ` Jae Hyun Yoo 2019-02-11 18:16 ` Wolfram Sang 2019-02-11 18:16 ` Wolfram Sang 2019-02-11 18:29 ` Jae Hyun Yoo 2019-02-11 18:29 ` Jae Hyun Yoo
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20190116193958.6049-1-jae.hyun.yoo@linux.intel.com \ --to=jae.hyun.yoo@linux.intel.com \ --cc=andrew@aj.id.au \ --cc=benh@kernel.crashing.org \ --cc=brendanhiggins@google.com \ --cc=james.feist@linux.intel.com \ --cc=jarkko.nikula@linux.intel.com \ --cc=joel@jms.id.au \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-aspeed@lists.ozlabs.org \ --cc=linux-i2c@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=openbmc@lists.ozlabs.org \ --cc=vernon.mauery@linux.intel.com \ --cc=wsa@the-dreams.de \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.