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7b6aa02efe
I was having intermittent i2c issues on the device until I applied this kernel patch which I found online. Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
33 lines
986 B
Diff
33 lines
986 B
Diff
Fix i2c timing errors.
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When Transmitting: Make SDA valid quarter of a cycle after the falling edge of SCL.
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When Receiving: Sample SDA Quarter of a cycle after the rising edge of SCL.
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Upstream-Status: Pending
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RP 2013/04/21
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Index: git/drivers/i2c/busses/i2c-bcm2708.c
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===================================================================
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--- git.orig/drivers/i2c/busses/i2c-bcm2708.c 2013-01-06 17:15:00.754954587 +0000
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+++ git/drivers/i2c/busses/i2c-bcm2708.c 2013-01-06 17:50:09.794905741 +0000
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@@ -150,6 +150,7 @@
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unsigned long bus_hz;
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u32 cdiv;
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u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1;
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+ u32 cdel;
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bus_hz = clk_get_rate(bi->clk);
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cdiv = bus_hz / baudrate;
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@@ -163,6 +164,10 @@
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bcm2708_wr(bi, BSC_A, bi->msg->addr);
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bcm2708_wr(bi, BSC_DLEN, bi->msg->len);
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bcm2708_wr(bi, BSC_C, c);
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+
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+ cdel = (cdiv / 4) & 0xffff;
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+ cdel = cdel << 16 | cdel;
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+ bcm2708_wr(bi, BSC_DEL, cdel);
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}
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static irqreturn_t bcm2708_i2c_interrupt(int irq, void *dev_id)
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