diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
-rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 199 |
1 files changed, 83 insertions, 116 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 599c0d7bd906..dfe1a53ce4ad 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -33,7 +33,6 @@ #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/slab.h> -#include <linux/spinlock.h> /* register offsets */ #define ICSCR 0x00 /* slave ctrl */ @@ -84,6 +83,7 @@ #define RCAR_BUS_PHASE_START (MDBS | MIE | ESG) #define RCAR_BUS_PHASE_DATA (MDBS | MIE) +#define RCAR_BUS_MASK_DATA (~(ESG | FSB) & 0xFF) #define RCAR_BUS_PHASE_STOP (MDBS | MIE | FSB) #define RCAR_IRQ_SEND (MNR | MAL | MST | MAT | MDE) @@ -94,7 +94,6 @@ #define RCAR_IRQ_ACK_RECV (~(MAT | MDR) & 0xFF) #define ID_LAST_MSG (1 << 0) -#define ID_IOERROR (1 << 1) #define ID_DONE (1 << 2) #define ID_ARBLOST (1 << 3) #define ID_NACK (1 << 4) @@ -108,10 +107,10 @@ enum rcar_i2c_type { struct rcar_i2c_priv { void __iomem *io; struct i2c_adapter adap; - struct i2c_msg *msg; + struct i2c_msg *msg; + int msgs_left; struct clk *clk; - spinlock_t lock; wait_queue_head_t wait; int pos; @@ -144,9 +143,10 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) { /* reset master mode */ rcar_i2c_write(priv, ICMIER, 0); - rcar_i2c_write(priv, ICMCR, 0); + rcar_i2c_write(priv, ICMCR, MDBS); rcar_i2c_write(priv, ICMSR, 0); - rcar_i2c_write(priv, ICMAR, 0); + /* start clock */ + rcar_i2c_write(priv, ICCCR, priv->icccr); } static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) @@ -257,16 +257,28 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) { int read = !!rcar_i2c_is_recv(priv); + priv->pos = 0; + priv->flags = 0; + if (priv->msgs_left == 1) + rcar_i2c_flags_set(priv, ID_LAST_MSG); + rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read); rcar_i2c_write(priv, ICMSR, 0); rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND); } +static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv) +{ + priv->msg++; + priv->msgs_left--; + rcar_i2c_prepare_msg(priv); +} + /* * interrupt functions */ -static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) +static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) { struct i2c_msg *msg = priv->msg; @@ -276,14 +288,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * Do nothing */ if (!(msr & MDE)) - return 0; - - /* - * If address transfer phase finished, - * goto data phase. - */ - if (msr & MAT) - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); + return; if (priv->pos < msg->len) { /* @@ -305,29 +310,23 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * [ICRXTX] -> [SHIFT] -> [I2C bus] */ - if (priv->flags & ID_LAST_MSG) + if (priv->flags & ID_LAST_MSG) { /* * If current msg is the _LAST_ msg, * prepare stop condition here. * ID_DONE will be set on STOP irq. */ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); - else - /* - * If current msg is _NOT_ last msg, - * it doesn't call stop phase. - * thus, there is no STOP irq. - * return ID_DONE here. - */ - return ID_DONE; + } else { + rcar_i2c_next_msg(priv); + return; + } } rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND); - - return 0; } -static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) +static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) { struct i2c_msg *msg = priv->msg; @@ -337,14 +336,10 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) * Do nothing */ if (!(msr & MDR)) - return 0; + return; if (msr & MAT) { - /* - * Address transfer phase finished, - * but, there is no data at this point. - * Do nothing. - */ + /* Address transfer phase finished, but no data at this point. */ } else if (priv->pos < msg->len) { /* * get received data @@ -360,12 +355,11 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) */ if (priv->pos + 1 >= msg->len) rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); - else - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); - - rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); - return 0; + if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG)) + rcar_i2c_next_msg(priv); + else + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); } static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) @@ -426,22 +420,21 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv) static irqreturn_t rcar_i2c_irq(int irq, void *ptr) { struct rcar_i2c_priv *priv = ptr; - irqreturn_t result = IRQ_HANDLED; - u32 msr; + u32 msr, val; - /*-------------- spin lock -----------------*/ - spin_lock(&priv->lock); - - if (rcar_i2c_slave_irq(priv)) - goto exit; + /* Clear START or STOP as soon as we can */ + val = rcar_i2c_read(priv, ICMCR); + rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA); msr = rcar_i2c_read(priv, ICMSR); /* Only handle interrupts that are currently enabled */ msr &= rcar_i2c_read(priv, ICMIER); if (!msr) { - result = IRQ_NONE; - goto exit; + if (rcar_i2c_slave_irq(priv)) + return IRQ_HANDLED; + + return IRQ_NONE; } /* Arbitration lost */ @@ -452,8 +445,7 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) /* Nack */ if (msr & MNR) { - /* go to stop phase */ - rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); + /* HW automatically sends STOP after received NACK */ rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP); rcar_i2c_flags_set(priv, ID_NACK); goto out; @@ -461,14 +453,15 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) /* Stop */ if (msr & MST) { + priv->msgs_left--; /* The last message also made it */ rcar_i2c_flags_set(priv, ID_DONE); goto out; } if (rcar_i2c_is_recv(priv)) - rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr)); + rcar_i2c_irq_recv(priv, msr); else - rcar_i2c_flags_set(priv, rcar_i2c_irq_send(priv, msr)); + rcar_i2c_irq_send(priv, msr); out: if (rcar_i2c_flags_has(priv, ID_DONE)) { @@ -477,11 +470,7 @@ out: wake_up(&priv->wait); } -exit: - spin_unlock(&priv->lock); - /*-------------- spin unlock -----------------*/ - - return result; + return IRQ_HANDLED; } static int rcar_i2c_master_xfer(struct i2c_adapter *adap, @@ -490,21 +479,12 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); struct device *dev = rcar_i2c_priv_to_dev(priv); - unsigned long flags; int i, ret; - long timeout; + long time_left; pm_runtime_get_sync(dev); - /*-------------- spin lock -----------------*/ - spin_lock_irqsave(&priv->lock, flags); - rcar_i2c_init(priv); - /* start clock */ - rcar_i2c_write(priv, ICCCR, priv->icccr); - - spin_unlock_irqrestore(&priv->lock, flags); - /*-------------- spin unlock -----------------*/ ret = rcar_i2c_bus_barrier(priv); if (ret < 0) @@ -514,48 +494,28 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, /* This HW can't send STOP after address phase */ if (msgs[i].len == 0) { ret = -EOPNOTSUPP; - break; - } - - /*-------------- spin lock -----------------*/ - spin_lock_irqsave(&priv->lock, flags); - - /* init each data */ - priv->msg = &msgs[i]; - priv->pos = 0; - priv->flags = 0; - if (i == num - 1) - rcar_i2c_flags_set(priv, ID_LAST_MSG); - - rcar_i2c_prepare_msg(priv); - - spin_unlock_irqrestore(&priv->lock, flags); - /*-------------- spin unlock -----------------*/ - - timeout = wait_event_timeout(priv->wait, - rcar_i2c_flags_has(priv, ID_DONE), - adap->timeout); - if (!timeout) { - ret = -ETIMEDOUT; - break; - } - - if (rcar_i2c_flags_has(priv, ID_NACK)) { - ret = -ENXIO; - break; - } - - if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { - ret = -EAGAIN; - break; - } - - if (rcar_i2c_flags_has(priv, ID_IOERROR)) { - ret = -EIO; - break; + goto out; } + } - ret = i + 1; /* The number of transfer */ + /* init data */ + priv->msg = msgs; + priv->msgs_left = num; + + rcar_i2c_prepare_msg(priv); + + time_left = wait_event_timeout(priv->wait, + rcar_i2c_flags_has(priv, ID_DONE), + num * adap->timeout); + if (!time_left) { + rcar_i2c_init(priv); + ret = -ETIMEDOUT; + } else if (rcar_i2c_flags_has(priv, ID_NACK)) { + ret = -ENXIO; + } else if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { + ret = -EAGAIN; + } else { + ret = num - priv->msgs_left; /* The number of transfer */ } out: pm_runtime_put(dev); @@ -650,23 +610,26 @@ static int rcar_i2c_probe(struct platform_device *pdev) return PTR_ERR(priv->clk); } + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->io = devm_ioremap_resource(dev, res); + if (IS_ERR(priv->io)) + return PTR_ERR(priv->io); + bus_speed = 100000; /* default 100 kHz */ of_property_read_u32(dev->of_node, "clock-frequency", &bus_speed); priv->devtype = (enum rcar_i2c_type)of_match_device(rcar_i2c_dt_ids, dev)->data; + pm_runtime_enable(dev); + pm_runtime_get_sync(dev); ret = rcar_i2c_clock_calculate(priv, bus_speed, dev); if (ret < 0) - return ret; + goto out_pm_put; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - priv->io = devm_ioremap_resource(dev, res); - if (IS_ERR(priv->io)) - return PTR_ERR(priv->io); + pm_runtime_put(dev); irq = platform_get_irq(pdev, 0); init_waitqueue_head(&priv->wait); - spin_lock_init(&priv->lock); adap = &priv->adap; adap->nr = pdev->id; @@ -682,22 +645,26 @@ static int rcar_i2c_probe(struct platform_device *pdev) dev_name(dev), priv); if (ret < 0) { dev_err(dev, "cannot get irq %d\n", irq); - return ret; + goto out_pm_disable; } - pm_runtime_enable(dev); platform_set_drvdata(pdev, priv); ret = i2c_add_numbered_adapter(adap); if (ret < 0) { dev_err(dev, "reg adap failed: %d\n", ret); - pm_runtime_disable(dev); - return ret; + goto out_pm_disable; } dev_info(dev, "probed\n"); return 0; + + out_pm_put: + pm_runtime_put(dev); + out_pm_disable: + pm_runtime_disable(dev); + return ret; } static int rcar_i2c_remove(struct platform_device *pdev) |