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path: root/drivers/i2c/busses/i2c-rcar.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c66
1 files changed, 48 insertions, 18 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 217def2d7cb4..12f6d452c0f7 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -91,7 +91,6 @@
#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)
@@ -120,6 +119,7 @@ enum rcar_i2c_type {
};
struct rcar_i2c_priv {
+ u32 flags;
void __iomem *io;
struct i2c_adapter adap;
struct i2c_msg *msg;
@@ -130,7 +130,6 @@ struct rcar_i2c_priv {
int pos;
u32 icccr;
- u32 flags;
u8 recovery_icmcr; /* protected by adapter lock */
enum rcar_i2c_type devtype;
struct i2c_client *slave;
@@ -621,27 +620,16 @@ static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
/*
* This driver has a lock-free design because there are IP cores (at least
* R-Car Gen2) which have an inherent race condition in their hardware design.
- * There, we need to clear RCAR_BUS_MASK_DATA bits as soon as possible after
+ * There, we need to switch to RCAR_BUS_PHASE_DATA as soon as possible after
* the interrupt was generated, otherwise an unwanted repeated message gets
* generated. It turned out that taking a spinlock at the beginning of the ISR
* was already causing repeated messages. Thus, this driver was converted to
* the now lockless behaviour. Please keep this in mind when hacking the driver.
+ * R-Car Gen3 seems to have this fixed but earlier versions than R-Car Gen2 are
+ * likely affected. Therefore, we have different interrupt handler entries.
*/
-static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
+static irqreturn_t rcar_i2c_irq(int irq, struct rcar_i2c_priv *priv, u32 msr)
{
- struct rcar_i2c_priv *priv = ptr;
- u32 msr, val;
-
- /* Clear START or STOP immediately, except for REPSTART after read */
- if (likely(!(priv->flags & ID_P_REP_AFTER_RD))) {
- 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) {
if (rcar_i2c_slave_irq(priv))
return IRQ_HANDLED;
@@ -685,6 +673,41 @@ out:
return IRQ_HANDLED;
}
+static irqreturn_t rcar_i2c_gen2_irq(int irq, void *ptr)
+{
+ struct rcar_i2c_priv *priv = ptr;
+ u32 msr;
+
+ /* Clear START or STOP immediately, except for REPSTART after read */
+ if (likely(!(priv->flags & ID_P_REP_AFTER_RD)))
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
+
+ /* Only handle interrupts that are currently enabled */
+ msr = rcar_i2c_read(priv, ICMSR);
+ msr &= rcar_i2c_read(priv, ICMIER);
+
+ return rcar_i2c_irq(irq, priv, msr);
+}
+
+static irqreturn_t rcar_i2c_gen3_irq(int irq, void *ptr)
+{
+ struct rcar_i2c_priv *priv = ptr;
+ u32 msr;
+
+ /* Only handle interrupts that are currently enabled */
+ msr = rcar_i2c_read(priv, ICMSR);
+ msr &= rcar_i2c_read(priv, ICMIER);
+
+ /*
+ * Clear START or STOP immediately, except for REPSTART after read or
+ * if a spurious interrupt was detected.
+ */
+ if (likely(!(priv->flags & ID_P_REP_AFTER_RD) && msr))
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA);
+
+ return rcar_i2c_irq(irq, priv, msr);
+}
+
static struct dma_chan *rcar_i2c_request_dma_chan(struct device *dev,
enum dma_transfer_direction dir,
dma_addr_t port_addr)
@@ -931,6 +954,8 @@ static int rcar_i2c_probe(struct platform_device *pdev)
struct rcar_i2c_priv *priv;
struct i2c_adapter *adap;
struct device *dev = &pdev->dev;
+ unsigned long irqflags = 0;
+ irqreturn_t (*irqhandler)(int irq, void *ptr) = rcar_i2c_gen3_irq;
int ret;
/* Otherwise logic will break because some bytes must always use PIO */
@@ -979,6 +1004,11 @@ static int rcar_i2c_probe(struct platform_device *pdev)
rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */
+ if (priv->devtype < I2C_RCAR_GEN3) {
+ irqflags |= IRQF_NO_THREAD;
+ irqhandler = rcar_i2c_gen2_irq;
+ }
+
if (priv->devtype == I2C_RCAR_GEN3) {
priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (!IS_ERR(priv->rstc)) {
@@ -998,7 +1028,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
priv->flags |= ID_P_HOST_NOTIFY;
priv->irq = platform_get_irq(pdev, 0);
- ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, dev_name(dev), priv);
+ ret = devm_request_irq(dev, priv->irq, irqhandler, irqflags, dev_name(dev), priv);
if (ret < 0) {
dev_err(dev, "cannot get irq %d\n", priv->irq);
goto out_pm_disable;