2578f0183c
On Ventana boards the Gateworks System Controller is the only device on I2C1 (/dev/i2c-0) and it can NAK transfers if it is busy in an ADC loop. Because this is a multi-function device with several slave addresses it is best to add retries at the controller level instead of within each slave driver. This adds a patch that adds 3 retries for i2c transactions only for Ventana boards and only for I2C1 Signed-off-by: Tim Harvey <tharvey@gateworks.com> Signed-off-by: Pushpal Sidhu <psidhu@gateworks.com> SVN-Revision: 48012
24 lines
893 B
Diff
24 lines
893 B
Diff
Index: linux-4.3/drivers/i2c/busses/i2c-imx.c
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===================================================================
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--- linux-4.3.orig/drivers/i2c/busses/i2c-imx.c 2015-11-01 16:05:25.000000000 -0800
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+++ linux-4.3/drivers/i2c/busses/i2c-imx.c 2015-12-18 10:39:44.971158318 -0800
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@@ -461,6 +461,8 @@
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{
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if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) {
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dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
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+ if (i2c_imx->adapter.retries)
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+ return -EAGAIN;
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return -EIO; /* No ACK */
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}
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@@ -1010,6 +1012,10 @@
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i2c_imx->adapter.nr = pdev->id;
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i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
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i2c_imx->base = base;
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+ if (of_machine_is_compatible("gw,ventana") && phy_addr == 0x021a0000) {
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+ dev_info(&pdev->dev, "Adding retries for Ventana GSC\n");
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+ i2c_imx->adapter.retries = 3;
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+ }
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/* Get I2C clock */
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i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
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