[KINETIS] Add I2C workaround for KL27Z.

2 files changed, 74 insertions, 3 deletions

diff --git a/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c b/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c
index ce59627..c6b3d11 100644
--- a/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c
+++ b/os/hal/ports/KINETIS/LLD/hal_i2c_lld.c
@@ -127,8 +127,20 @@ static void serve_interrupt(I2CDriver *i2cp) {
       i2c->S |= I2Cx_S_ARBL;

       /* TODO: may need to do more here, reset bus? */

       /* Perhaps clear MST? */

+    }

+

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+    else if ((i2cp->rsta_workaround == RSTA_WORKAROUND_ON) && (i2cp->i2c->FLT & I2Cx_FLT_STARTF)) {

+      i2cp->rsta_workaround = RSTA_WORKAROUND_OFF;

+      /* clear+disable STARTF/STOPF interrupts and wake up the thread */

+      i2cp->i2c->FLT |= I2Cx_FLT_STOPF|I2Cx_FLT_STARTF;

+      i2cp->i2c->FLT &= ~I2Cx_FLT_SSIE;

+      i2c->S |= I2Cx_S_IICIF;

+      _i2c_wakeup_isr(i2cp);

+    }

+#endif /* KL27Z RST workaround */

 

-    } else if (i2c->S & I2Cx_S_TCF) {

+    else if (i2c->S & I2Cx_S_TCF) {

       /* just completed byte transfer */

       if (i2c->C1 & I2Cx_C1_TX) {

         /* the byte was transmitted */

@@ -213,7 +225,6 @@ static void serve_interrupt(I2CDriver *i2cp) {
       }

 

     } /* possibly check other interrupt flags here */

-

   } else {

     /* slave */

 

@@ -379,6 +390,10 @@ static inline msg_t _i2c_txrx_timeout(I2CDriver *i2cp, i2caddr_t addr,
   i2cp->rxbytes = rxbytes;

   i2cp->rxidx = 0;

 

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+  i2cp->rsta_workaround = RSTA_WORKAROUND_OFF;

+#endif /* KL27Z RST workaround */

+

   /* clear status flags */

 #if defined(I2Cx_FLT_STOPF) /* extra flags on KL26Z and KL27Z */

   i2cp->i2c->FLT |= I2Cx_FLT_STOPF;

@@ -391,8 +406,34 @@ static inline msg_t _i2c_txrx_timeout(I2CDriver *i2cp, i2caddr_t addr,
   /* acquire the bus */

   /* check to see if we already have the bus */

   if(i2cp->i2c->C1 & I2Cx_C1_MST) {

+

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+    /* need to wait for STARTF interrupt after issuing repeated start,

+     * otherwise the double buffering mechanism sends the last sent byte

+     * instead of the slave address.

+     * https://community.freescale.com/thread/377611

+     */

+    i2cp->rsta_workaround = RSTA_WORKAROUND_ON;

+    /* clear any interrupt bits and enable STARTF/STOPF interrupts */

+    i2cp->i2c->FLT |= I2Cx_FLT_STOPF|I2Cx_FLT_STARTF;

+    i2cp->i2c->S |= I2Cx_S_IICIF|I2Cx_S_ARBL;

+    i2cp->i2c->FLT |= I2Cx_FLT_SSIE;

+#endif /* KL27Z RST workaround */

+

     /* send repeated start */

     i2cp->i2c->C1 |= I2Cx_C1_RSTA | I2Cx_C1_TX;

+

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+    /* wait for the STARTF interrupt */

+    msg = osalThreadSuspendTimeoutS(&i2cp->thread, timeout);

+    /* abort if this didn't go well (timed out) */

+    if (msg != MSG_OK) {

+      /* release bus - RX mode, send STOP */

+      i2cp->i2c->C1 &= ~(I2Cx_C1_TX | I2Cx_C1_MST);

+      return msg;

+    }

+#endif /* KL27Z RST workaround */

+

   } else {

     /* unlock during the wait, so that tasks with

      * higher priority can get attention */

@@ -434,8 +475,30 @@ static inline msg_t _i2c_txrx_timeout(I2CDriver *i2cp, i2caddr_t addr,
   /* the transmitting (or receiving if no transmission) phase has finished,

    * do we expect to receive something? */

   if (msg == MSG_OK && rxbuf != NULL && rxbytes > 0 && i2cp->rxidx < rxbytes) {

+

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+    /* the same KL27Z RST workaround as above */

+    i2cp->rsta_workaround = RSTA_WORKAROUND_ON;

+    /* clear any interrupt bits and enable STARTF/STOPF interrupts */

+    i2cp->i2c->FLT |= I2Cx_FLT_STOPF|I2Cx_FLT_STARTF;

+    i2cp->i2c->S |= I2Cx_S_IICIF|I2Cx_S_ARBL;

+    i2cp->i2c->FLT |= I2Cx_FLT_SSIE;

+#endif /* KL27Z RST workaround */

+

     /* send repeated start */

     i2cp->i2c->C1 |= I2Cx_C1_RSTA;

+

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+    /* wait for the STARTF interrupt */

+    msg = osalThreadSuspendTimeoutS(&i2cp->thread, timeout);

+    /* abort if this didn't go well (timed out) */

+    if (msg != MSG_OK) {

+      /* release bus - RX mode, send STOP */

+      i2cp->i2c->C1 &= ~(I2Cx_C1_TX | I2Cx_C1_MST);

+      return msg;

+    }

+#endif /* KL27Z RST workaround */

+

     /* FIXME */

     // while (!(i2cp->i2c->S & I2Cx_S_BUSY));

 

diff --git a/os/hal/ports/KINETIS/LLD/hal_i2c_lld.h b/os/hal/ports/KINETIS/LLD/hal_i2c_lld.h
index 2b25df2..3576b60 100644
--- a/os/hal/ports/KINETIS/LLD/hal_i2c_lld.h
+++ b/os/hal/ports/KINETIS/LLD/hal_i2c_lld.h
@@ -34,7 +34,11 @@
 #define STATE_STOP    0x00

 #define STATE_SEND    0x01

 #define STATE_RECV    0x02

-#define STATE_DUMMY   0x03

+

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+#define RSTA_WORKAROUND_OFF    0x00

+#define RSTA_WORKAROUND_ON     0x01

+#endif /* KL27Z RST workaround */

 

 /*===========================================================================*/

 /* Driver pre-compile time settings.                                         */

@@ -188,6 +192,10 @@ struct I2CDriver {
   intstate_t                intstate;

   /* @brief Low-level register access. */

   I2C_TypeDef               *i2c;

+#if defined(KL27Zxxx) || defined(KL27Zxx) /* KL27Z RST workaround */

+  /* @brief Auxiliary variable for KL27Z repeated start workaround. */

+  intstate_t                rsta_workaround;

+#endif /* KL27Z RST workaround */

 };

 

 /*===========================================================================*/