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Commit 45da790e authored by Joakim Tjernlund's avatar Joakim Tjernlund Committed by Ben Dooks
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i2c-mpc: Do not generate STOP after read. 



The driver always ends a read with a STOP condition which
breaks subsequent I2C reads/writes in the same transaction as
these expect to do a repeated START(ReSTART).

This will also help I2C multimaster as the bus will not be released
after the first read, but when the whole transaction ends.

Signed-off-by: default avatarJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent db3a3d4e

drivers/i2c/busses/i2c-mpc.c

+2 −8
Original line number Diff line number Diff line
@@ -365,9 +365,6 @@ static int mpc_write(struct mpc_i2c *i2c, int target, 
	unsigned timeout = i2c->adap.timeout;

	u32 flags = restart ? CCR_RSTA : 0;



	/* Start with MEN */

	if (!restart)

		writeccr(i2c, CCR_MEN);

	/* Start as master */

	writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);

	/* Write target byte */
@@ -396,9 +393,6 @@ static int mpc_read(struct mpc_i2c *i2c, int target, 
	int i, result;

	u32 flags = restart ? CCR_RSTA : 0;



	/* Start with MEN */

	if (!restart)

		writeccr(i2c, CCR_MEN);

	/* Switch to read - restart */

	writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);

	/* Write target address byte - this time with the read flag set */
@@ -425,9 +419,9 @@ static int mpc_read(struct mpc_i2c *i2c, int target, 
		/* Generate txack on next to last byte */

		if (i == length - 2)

			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);

		/* Generate stop on last byte */

		/* Do not generate stop on last byte */

		if (i == length - 1)

			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK);

			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);

		data[i] = readb(i2c->base + MPC_I2C_DR);

	}