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i2c: rcar: implement atomic transfers
Implements atomic transfers. Tested by rebooting an r8a7790 Lager board after connecting the i2c-rcar controller to the PMIC in arch/arm/boot/dts/r8a7790-lager.dts like so: compatible = "i2c-demux-pinctrl"; pinctrl-names = "default"; pinctrl-0 = <&pmic_irq_pins>; - i2c-parent = <&iic3>, <&i2c3>; + i2c-parent = <&i2c3>, <&iic3>; i2c-bus-name = "i2c-pwr"; #address-cells = <1>; #size-cells = <0>; Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Ulrich Hecht
Wolfram Sang
parent
b87752528f
commit
82531dfdf1
1 changed files with 78 additions and 6 deletions
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@ -141,6 +141,7 @@ struct rcar_i2c_priv {
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enum dma_data_direction dma_direction;
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struct reset_control *rstc;
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bool atomic_xfer;
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int irq;
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struct i2c_client *host_notify_client;
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@ -353,6 +354,8 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
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rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
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rcar_i2c_write(priv, ICMSR, 0);
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}
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if (!priv->atomic_xfer)
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rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
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}
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@ -418,7 +421,7 @@ static bool rcar_i2c_dma(struct rcar_i2c_priv *priv)
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int len;
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/* Do various checks to see if DMA is feasible at all */
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if (IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||
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if (priv->atomic_xfer || IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||
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!(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA))
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return false;
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@ -646,6 +649,7 @@ static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr)
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/* Nack */
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if (msr & MNR) {
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/* HW automatically sends STOP after received NACK */
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if (!priv->atomic_xfer)
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rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
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priv->flags |= ID_NACK;
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goto out;
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@ -667,6 +671,7 @@ static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr)
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if (priv->flags & ID_DONE) {
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rcar_i2c_write(priv, ICMIER, 0);
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rcar_i2c_write(priv, ICMSR, 0);
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if (!priv->atomic_xfer)
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wake_up(&priv->wait);
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}
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@ -684,6 +689,7 @@ static irqreturn_t rcar_i2c_gen2_irq(int irq, void *ptr)
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/* Only handle interrupts that are currently enabled */
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msr = rcar_i2c_read(priv, ICMSR);
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if (!priv->atomic_xfer)
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msr &= rcar_i2c_read(priv, ICMIER);
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return rcar_i2c_irq(irq, priv, msr);
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@ -696,6 +702,7 @@ static irqreturn_t rcar_i2c_gen3_irq(int irq, void *ptr)
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/* Only handle interrupts that are currently enabled */
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msr = rcar_i2c_read(priv, ICMSR);
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if (!priv->atomic_xfer)
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msr &= rcar_i2c_read(priv, ICMIER);
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/*
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@ -804,6 +811,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
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int i, ret;
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long time_left;
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priv->atomic_xfer = false;
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pm_runtime_get_sync(dev);
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/* Check bus state before init otherwise bus busy info will be lost */
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@ -858,6 +867,68 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
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return ret;
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}
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static int rcar_i2c_master_xfer_atomic(struct i2c_adapter *adap,
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struct i2c_msg *msgs,
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int num)
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{
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struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
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struct device *dev = rcar_i2c_priv_to_dev(priv);
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unsigned long j;
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bool time_left;
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int ret;
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priv->atomic_xfer = true;
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pm_runtime_get_sync(dev);
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/* Check bus state before init otherwise bus busy info will be lost */
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ret = rcar_i2c_bus_barrier(priv);
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if (ret < 0)
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goto out;
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rcar_i2c_init(priv);
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/* init first message */
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priv->msg = msgs;
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priv->msgs_left = num;
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priv->flags = (priv->flags & ID_P_MASK) | ID_FIRST_MSG;
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rcar_i2c_prepare_msg(priv);
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j = jiffies + num * adap->timeout;
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do {
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u32 msr = rcar_i2c_read(priv, ICMSR);
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msr &= (rcar_i2c_is_recv(priv) ? RCAR_IRQ_RECV : RCAR_IRQ_SEND) | RCAR_IRQ_STOP;
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if (msr) {
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if (priv->devtype < I2C_RCAR_GEN3)
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rcar_i2c_gen2_irq(0, priv);
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else
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rcar_i2c_gen3_irq(0, priv);
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}
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time_left = time_before_eq(jiffies, j);
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} while (!(priv->flags & ID_DONE) && time_left);
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if (!time_left) {
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rcar_i2c_init(priv);
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ret = -ETIMEDOUT;
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} else if (priv->flags & ID_NACK) {
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ret = -ENXIO;
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} else if (priv->flags & ID_ARBLOST) {
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ret = -EAGAIN;
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} else {
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ret = num - priv->msgs_left; /* The number of transfer */
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}
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out:
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pm_runtime_put(dev);
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if (ret < 0 && ret != -ENXIO)
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dev_err(dev, "error %d : %x\n", ret, priv->flags);
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return ret;
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}
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static int rcar_reg_slave(struct i2c_client *slave)
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{
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struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
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@ -922,6 +993,7 @@ static u32 rcar_i2c_func(struct i2c_adapter *adap)
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static const struct i2c_algorithm rcar_i2c_algo = {
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.master_xfer = rcar_i2c_master_xfer,
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.master_xfer_atomic = rcar_i2c_master_xfer_atomic,
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.functionality = rcar_i2c_func,
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.reg_slave = rcar_reg_slave,
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.unreg_slave = rcar_unreg_slave,
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