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@xxxxxxxx>
---
drivers/i2c/busses/i2c-rcar.c | 84 ++++++++++++++++++++++++++++++++---
1 file changed, 78 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 12f6d452c0f7..1f0c164f671a 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -141,6 +141,7 @@ struct rcar_i2c_priv {
enum dma_data_direction dma_direction;
struct reset_control *rstc;
+ bool atomic_xfer;
int irq;
struct i2c_client *host_notify_client;
@@ -353,7 +354,9 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
rcar_i2c_write(priv, ICMSR, 0);
}
- rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
+
+ if (!priv->atomic_xfer)
+ rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
}
static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
@@ -418,7 +421,7 @@ static bool rcar_i2c_dma(struct rcar_i2c_priv *priv)
int len;
/* Do various checks to see if DMA is feasible at all */
- if (IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||
+ if (priv->atomic_xfer || IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||
!(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA))
return false;
@@ -646,7 +649,8 @@ static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr)
/* Nack */
if (msr & MNR) {
/* HW automatically sends STOP after received NACK */
- rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
+ if (!priv->atomic_xfer)
+ rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
priv->flags |= ID_NACK;
goto out;
}
@@ -667,7 +671,8 @@ static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr)
if (priv->flags & ID_DONE) {
rcar_i2c_write(priv, ICMIER, 0);
rcar_i2c_write(priv, ICMSR, 0);
- wake_up(&priv->wait);
+ if (!priv->atomic_xfer)
+ wake_up(&priv->wait);
}
return IRQ_HANDLED;
@@ -684,7 +689,8 @@ static irqreturn_t rcar_i2c_gen2_irq(int irq, void *ptr)
/* Only handle interrupts that are currently enabled */
msr = rcar_i2c_read(priv, ICMSR);
- msr &= rcar_i2c_read(priv, ICMIER);
+ if (!priv->atomic_xfer)
+ msr &= rcar_i2c_read(priv, ICMIER);
return rcar_i2c_irq(irq, priv, msr);
}
@@ -696,7 +702,8 @@ static irqreturn_t rcar_i2c_gen3_irq(int irq, void *ptr)
/* Only handle interrupts that are currently enabled */
msr = rcar_i2c_read(priv, ICMSR);
- msr &= rcar_i2c_read(priv, ICMIER);
+ if (!priv->atomic_xfer)
+ msr &= rcar_i2c_read(priv, ICMIER);
/*
* Clear START or STOP immediately, except for REPSTART after read or
@@ -804,6 +811,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
int i, ret;
long time_left;
+ priv->atomic_xfer = false;
+
pm_runtime_get_sync(dev);
/* Check bus state before init otherwise bus busy info will be lost */
@@ -858,6 +867,68 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
return ret;
}
+static int rcar_i2c_master_xfer_atomic(struct i2c_adapter *adap,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+ struct device *dev = rcar_i2c_priv_to_dev(priv);
+ unsigned long j;
+ bool time_left;
+ int ret;
+
+ priv->atomic_xfer = true;
+
+ pm_runtime_get_sync(dev);
+
+ /* Check bus state before init otherwise bus busy info will be lost */
+ ret = rcar_i2c_bus_barrier(priv);
+ if (ret < 0)
+ goto out;
+
+ rcar_i2c_init(priv);
+
+ /* init first message */
+ priv->msg = msgs;
+ priv->msgs_left = num;
+ priv->flags = (priv->flags & ID_P_MASK) | ID_FIRST_MSG;
+ rcar_i2c_prepare_msg(priv);
+
+ j = jiffies + num * adap->timeout;
+ do {
+ u32 msr = rcar_i2c_read(priv, ICMSR);
+
+ msr &= (rcar_i2c_is_recv(priv) ? RCAR_IRQ_RECV : RCAR_IRQ_SEND) | RCAR_IRQ_STOP;
+
+ if (msr) {
+ if (priv->devtype < I2C_RCAR_GEN3)
+ rcar_i2c_gen2_irq(0, priv);
+ else
+ rcar_i2c_gen3_irq(0, priv);
+ }
+
+ time_left = time_before_eq(jiffies, j);
+ } while (!(priv->flags & ID_DONE) && time_left);
+
+ if (!time_left) {
+ rcar_i2c_init(priv);
+ ret = -ETIMEDOUT;
+ } else if (priv->flags & ID_NACK) {
+ ret = -ENXIO;
+ } else if (priv->flags & ID_ARBLOST) {
+ ret = -EAGAIN;
+ } else {
+ ret = num - priv->msgs_left; /* The number of transfer */
+ }
+out:
+ pm_runtime_put(dev);
+
+ if (ret < 0 && ret != -ENXIO)
+ dev_err(dev, "error %d : %x\n", ret, priv->flags);
+
+ return ret;
+}
+
static int rcar_reg_slave(struct i2c_client *slave)
{
struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
@@ -922,6 +993,7 @@ static u32 rcar_i2c_func(struct i2c_adapter *adap)
static const struct i2c_algorithm rcar_i2c_algo = {
.master_xfer = rcar_i2c_master_xfer,
+ .master_xfer_atomic = rcar_i2c_master_xfer_atomic,
.functionality = rcar_i2c_func,
.reg_slave = rcar_reg_slave,
.unreg_slave = rcar_unreg_slave,
--
2.20.1
