i2c: img-scb: add handle for stop detected interrupt

Stop Detected interrupt is triggered when a Stop bit is detected on
the bus, which indicates the end of the current transfer.

When the end of a transfer is indicated by the Stop Detected interrupt,
drain the FIFO and signal completion for the transaction.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/i2c/busses/i2c-img-scb.c b/drivers/i2c/busses/i2c-img-scb.c
index 0af554a16ae5..f416010a0b49 100644
--- a/drivers/i2c/busses/i2c-img-scb.c
+++ b/drivers/i2c/busses/i2c-img-scb.c
@@ -152,6 +152,7 @@
 #define INT_TRANSACTION_DONE            BIT(15)
 #define INT_SLAVE_EVENT                 BIT(16)
 #define INT_TIMING                      BIT(18)
+#define INT_STOP_DETECTED               BIT(19)
 
 #define INT_FIFO_FULL_FILLING   (INT_FIFO_FULL  | INT_FIFO_FILLING)
 
@@ -175,7 +176,8 @@
                                          INT_WRITE_ACK_ERR    | \
                                          INT_FIFO_FULL        | \
                                          INT_FIFO_FILLING     | \
-                                         INT_FIFO_EMPTY)
+                                         INT_FIFO_EMPTY       | \
+                                         INT_STOP_DETECTED)
 
 #define INT_ENABLE_MASK_WAITSTOP        (INT_SLAVE_EVENT      | \
                                          INT_ADDR_ACK_ERR     | \
@@ -865,6 +867,13 @@ static unsigned int img_i2c_auto(struct img_i2c *i2c,
 
         mod_timer(&i2c->check_timer, jiffies + msecs_to_jiffies(1));
 
+        if (int_status & INT_STOP_DETECTED) {
+                /* Drain remaining data in FIFO and complete transaction */
+                if (i2c->msg.flags & I2C_M_RD)
+                        img_i2c_read_fifo(i2c);
+                return ISR_COMPLETE(0);
+        }
+
         if (i2c->msg.flags & I2C_M_RD) {
                 if (int_status & INT_FIFO_FULL_FILLING) {
                         img_i2c_read_fifo(i2c);