From 46bdcb1c8ec12e6e69f1420dcb2e50549ef28d64 Mon Sep 17 00:00:00 2001
From: emlsyx <yangx_1118@163.com>
Date: Sun, 18 Jul 2021 20:19:19 +0800
Subject: [PATCH] fix imxrt i2c drives read failure bug

---
 bsp/imxrt/libraries/drivers/drv_i2c.c | 101 +++++---------------------
 1 file changed, 19 insertions(+), 82 deletions(-)

diff --git a/bsp/imxrt/libraries/drivers/drv_i2c.c b/bsp/imxrt/libraries/drivers/drv_i2c.c
index 117b29f3d3..3ad48de112 100644
--- a/bsp/imxrt/libraries/drivers/drv_i2c.c
+++ b/bsp/imxrt/libraries/drivers/drv_i2c.c
@@ -8,6 +8,7 @@
  * 2017-08-08     Yang         the first version
  * 2018-03-24     LaiYiKeTang  add hardware iic
  * 2019-04-22     tyustli      add imxrt series support
+ * 2021-07-18     emlsyx       fix read failure bug
  *
  */
 
@@ -126,81 +127,24 @@ static rt_err_t imxrt_lpi2c_configure(struct imxrt_i2c_bus *bus, lpi2c_master_co
     LPI2C_MasterInit(bus->I2C, cfg, LPI2C_CLOCK_FREQUENCY);
     return RT_EOK;
 }
-
-status_t LPI2C_MasterCheck(LPI2C_Type *base, uint32_t status)
+static rt_err_t imxrt_lpi2c_wait_fifo_empty(LPI2C_Type *base)
 {
-    status_t result = kStatus_Success;
+    size_t tx_count = 0xFFU;
+    size_t rx_count = 0xFFU;
 
-    /* Check for error. These errors cause a stop to automatically be sent. We must */
-    /* clear the errors before a new transfer can start. */
-    status &= 0x3c00;
-    if (status)
+    /* Check master tx FIFO empty or not */
+    LPI2C_MasterGetFifoCounts(base, &rx_count, &tx_count);
+    while (tx_count || rx_count)
     {
-        /* Select the correct error code. Ordered by severity, with bus issues first. */
-        if (status & kLPI2C_MasterPinLowTimeoutFlag)
-        {
-            result = kStatus_LPI2C_PinLowTimeout;
-        }
-        else if (status & kLPI2C_MasterArbitrationLostFlag)
-        {
-            result = kStatus_LPI2C_ArbitrationLost;
-        }
-        else if (status & kLPI2C_MasterNackDetectFlag)
-        {
-            result = kStatus_LPI2C_Nak;
-        }
-        else if (status & kLPI2C_MasterFifoErrFlag)
-        {
-            result = kStatus_LPI2C_FifoError;
-        }
-        else
-        {
-            assert(false);
-        }
-
-        /* Clear the flags. */
-        LPI2C_MasterClearStatusFlags(base, status);
-
-        /* Reset fifos. These flags clear automatically. */
-        base->MCR |= LPI2C_MCR_RRF_MASK | LPI2C_MCR_RTF_MASK;
+        LPI2C_MasterGetFifoCounts(base, &rx_count, &tx_count);
     }
 
-    return result;
-}
-
-/*!
- * @brief Wait until the tx fifo all empty.
- * @param base The LPI2C peripheral base address.
- * @retval #kStatus_Success
- * @retval #kStatus_LPI2C_PinLowTimeout
- * @retval #kStatus_LPI2C_ArbitrationLost
- * @retval #kStatus_LPI2C_Nak
- * @retval #kStatus_LPI2C_FifoError
- */
-static status_t LPI2C_MasterWaitForTxFifoAllEmpty(LPI2C_Type *base)
-{
-    uint32_t status;
-    size_t txCount;
-
-    do
+    /* Check communicate with slave successful or not */
+    if (LPI2C_MasterGetStatusFlags(base) & kLPI2C_MasterNackDetectFlag)
     {
-        status_t result;
-
-        /* Get the number of words in the tx fifo and compute empty slots. */
-        LPI2C_MasterGetFifoCounts(base, NULL, &txCount);
-
-        /* Check for error flags. */
-        status = LPI2C_MasterGetStatusFlags(base);
-        result = LPI2C_MasterCheck(base, status);
-        if (result)
-        {
-            return result;
-        }
+        return RT_EEMPTY;
     }
-
-    while (txCount);
-
-    return kStatus_Success;
+    return RT_EOK;
 }
 
 static rt_size_t imxrt_i2c_mst_xfer(struct rt_i2c_bus_device *bus,
@@ -221,17 +165,14 @@ static rt_size_t imxrt_i2c_mst_xfer(struct rt_i2c_bus_device *bus,
     {
         if (imxrt_i2c->msg[i].flags & RT_I2C_RD)
         {
-            if (LPI2C_MasterStart(imxrt_i2c->I2C, imxrt_i2c->msg[i].addr, kLPI2C_Write) != kStatus_Success)
+            if (LPI2C_MasterStart(imxrt_i2c->I2C, imxrt_i2c->msg[i].addr, kLPI2C_Read) != kStatus_Success)
             {
                 i = 0;
                 break;
             }
 
-            while (LPI2C_MasterGetStatusFlags(imxrt_i2c->I2C) & kLPI2C_MasterNackDetectFlag)
-            {
-            }
-
-            if (LPI2C_MasterRepeatedStart(imxrt_i2c->I2C, imxrt_i2c->msg[i].addr, kLPI2C_Read) != kStatus_Success)
+            /* Check communicate with slave successful or not */
+            if (RT_EOK != imxrt_lpi2c_wait_fifo_empty(imxrt_i2c->I2C))
             {
                 i = 0;
                 break;
@@ -251,17 +192,14 @@ static rt_size_t imxrt_i2c_mst_xfer(struct rt_i2c_bus_device *bus,
                 break;
             }
 
-            while (LPI2C_MasterGetStatusFlags(imxrt_i2c->I2C) & kLPI2C_MasterNackDetectFlag)
-            {
-            }
-
-            if (LPI2C_MasterSend(imxrt_i2c->I2C, imxrt_i2c->msg[i].buf, imxrt_i2c->msg[i].len) != kStatus_Success)
+            /* Check communicate with slave successful or not */
+            if (RT_EOK != imxrt_lpi2c_wait_fifo_empty(imxrt_i2c->I2C))
             {
                 i = 0;
                 break;
             }
 
-            if (LPI2C_MasterWaitForTxFifoAllEmpty(imxrt_i2c->I2C) != kStatus_Success)
+            if (LPI2C_MasterSend(imxrt_i2c->I2C, imxrt_i2c->msg[i].buf, imxrt_i2c->msg[i].len) != kStatus_Success)
             {
                 i = 0;
                 break;
@@ -351,7 +289,6 @@ int rt_hw_i2c_init(void)
 
     return 0;
 }
-
-INIT_DEVICE_EXPORT(rt_hw_i2c_init);
+INIT_BOARD_EXPORT(rt_hw_i2c_init);
 
 #endif /* BSP_USING_I2C */
-- 
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