1 files changed, 41 insertions, 2 deletions

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 650293ff4d62..9f1423ac7b3b 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -106,6 +106,16 @@
 /* maximum threshold value */
 #define MAX_I2C_FIFO_THRESHOLD  15
 
+/**
+ * struct i2c_vendor_data - per-vendor variations
+ * @has_mtdws: variant has the MTDWS bit
+ * @fifodepth: variant FIFO depth
+ */
+struct i2c_vendor_data {
+        bool has_mtdws;
+        u32 fifodepth;
+};
+
 enum i2c_status {
         I2C_NOP,
         I2C_ON_GOING,
@@ -138,6 +148,7 @@ struct i2c_nmk_client {
 
 /**
  * struct nmk_i2c_dev - private data structure of the controller.
+ * @vendor: vendor data for this variant.
  * @adev: parent amba device.
  * @adap: corresponding I2C adapter.
  * @irq: interrupt line for the controller.
@@ -155,6 +166,7 @@ struct i2c_nmk_client {
  * @busy: Busy doing transfer.
  */
 struct nmk_i2c_dev {
+        struct i2c_vendor_data          *vendor;
         struct amba_device              *adev;
         struct i2c_adapter              adap;
         int                             irq;
@@ -431,7 +443,7 @@ static int read_i2c(struct nmk_i2c_dev *dev, u16 flags)
         irq_mask = (I2C_IT_RXFNF | I2C_IT_RXFF |
                         I2C_IT_MAL | I2C_IT_BERR);
 
-        if (dev->stop)
+        if (dev->stop || !dev->vendor->has_mtdws)
                 irq_mask |= I2C_IT_MTD;
         else
                 irq_mask |= I2C_IT_MTDWS;
@@ -511,7 +523,7 @@ static int write_i2c(struct nmk_i2c_dev *dev, u16 flags)
          * set the MTDWS bit (Master Transaction Done Without Stop)
          * to start repeated start operation
          */
-        if (dev->stop)
+        if (dev->stop || !dev->vendor->has_mtdws)
                 irq_mask |= I2C_IT_MTD;
         else
                 irq_mask |= I2C_IT_MTDWS;
@@ -978,6 +990,8 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
         struct device_node *np = adev->dev.of_node;
         struct nmk_i2c_dev      *dev;
         struct i2c_adapter *adap;
+        struct i2c_vendor_data *vendor = id->data;
+        u32 max_fifo_threshold = (vendor->fifodepth / 2) - 1;
 
         if (!pdata) {
                 if (np) {
@@ -994,12 +1008,25 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
                         pdata = &u8500_i2c;
         }
 
+        if (pdata->tft > max_fifo_threshold) {
+                dev_warn(&adev->dev, "requested TX FIFO threshold %u, adjusted down to %u\n",
+                        pdata->tft, max_fifo_threshold);
+                pdata->tft = max_fifo_threshold;
+        }
+
+        if (pdata->rft > max_fifo_threshold) {
+                dev_warn(&adev->dev, "requested RX FIFO threshold %u, adjusted down to %u\n",
+                        pdata->rft, max_fifo_threshold);
+                pdata->rft = max_fifo_threshold;
+        }
+
         dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
         if (!dev) {
                 dev_err(&adev->dev, "cannot allocate memory\n");
                 ret = -ENOMEM;
                 goto err_no_mem;
         }
+        dev->vendor = vendor;
         dev->busy = false;
         dev->adev = adev;
         amba_set_drvdata(adev, dev);
@@ -1134,14 +1161,26 @@ static int nmk_i2c_remove(struct amba_device *adev)
         return 0;
 }
 
+static struct i2c_vendor_data vendor_stn8815 = {
+        .has_mtdws = false,
+        .fifodepth = 16, /* Guessed from TFTR/RFTR = 7 */
+};
+
+static struct i2c_vendor_data vendor_db8500 = {
+        .has_mtdws = true,
+        .fifodepth = 32, /* Guessed from TFTR/RFTR = 15 */
+};
+
 static struct amba_id nmk_i2c_ids[] = {
         {
                 .id     = 0x00180024,
                 .mask   = 0x00ffffff,
+                .data   = &vendor_stn8815,
         },
         {
                 .id     = 0x00380024,
                 .mask   = 0x00ffffff,
+                .data   = &vendor_db8500,
         },
         {},
 };