i2c: tegra: update transfer timeout

Tegra194 allows max of 64K bytes and Tegra186 and prior allows
max of 4K bytes of transfer per packet.

one sec timeout is not enough for transfers more than 10K bytes
at STD bus rate.

This patch updates I2C transfer timeout based on the transfer size
and I2C bus rate to allow enough time during max transfer size at
lower bus speed.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 3b92341..cfecd81 100644 (file)
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -24,7 +24,6 @@
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
-#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
 #define BYTES_PER_FIFO_WORD 4
 
 #define I2C_CNFG                               0x000
@@ -936,7 +935,7 @@ static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
        tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
 
        time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
-                                               TEGRA_I2C_TIMEOUT);
+                                               msecs_to_jiffies(50));
        if (time_left == 0) {
                dev_err(i2c_dev->dev, "timed out for bus clear\n");
                return -ETIMEDOUT;
@@ -963,6 +962,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
        u32 *buffer = NULL;
        int err = 0;
        bool dma;
+       u16 xfer_time = 100;
 
        tegra_i2c_flush_fifos(i2c_dev);
 
@@ -982,6 +982,12 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
                                    i2c_dev->dma_buf;
        tegra_i2c_config_fifo_trig(i2c_dev, xfer_size);
        dma = i2c_dev->is_curr_dma_xfer;
+       /*
+        * Transfer time in mSec = Total bits / transfer rate
+        * Total bits = 9 bits per byte (including ACK bit) + Start & stop bits
+        */
+       xfer_time += DIV_ROUND_CLOSEST(((xfer_size * 9) + 2) * MSEC_PER_SEC,
+                                       i2c_dev->bus_clk_rate);
        spin_lock_irqsave(&i2c_dev->xfer_lock, flags);
 
        int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
@@ -1085,7 +1091,7 @@ unlock:
 
                time_left = wait_for_completion_timeout(
                                                &i2c_dev->dma_complete,
-                                               TEGRA_I2C_TIMEOUT);
+                                               msecs_to_jiffies(xfer_time));
                if (time_left == 0) {
                        dev_err(i2c_dev->dev, "DMA transfer timeout\n");
                        dmaengine_terminate_sync(i2c_dev->msg_read ?
@@ -1111,7 +1117,7 @@ unlock:
        }
 
        time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
-                                               TEGRA_I2C_TIMEOUT);
+                                               msecs_to_jiffies(xfer_time));
        tegra_i2c_mask_irq(i2c_dev, int_mask);
 
        if (time_left == 0) {
@@ -1390,6 +1396,7 @@ static int tegra_i2c_probe(struct platform_device *pdev)
        i2c_dev->div_clk = div_clk;
        i2c_dev->adapter.algo = &tegra_i2c_algo;
        i2c_dev->adapter.retries = 1;
+       i2c_dev->adapter.timeout = 6 * HZ;
        i2c_dev->irq = irq;
        i2c_dev->cont_id = pdev->id;
        i2c_dev->dev = &pdev->dev;