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Commit a291702b authored by Wolfram Sang's avatar Wolfram Sang Committed by Greg Kroah-Hartman
Browse files

i2c: rcar: bring hardware to known state when probing 



[ Upstream commit 4e36c0f20cb1c74c7bd7ea31ba432c1c4a989031 ]

When probing, the hardware is not brought into a known state. This may
be a problem when a hypervisor restarts Linux without resetting the
hardware, leaving an old state running. Make sure the hardware gets
initialized, especially interrupts should be cleared and disabled.

Reported-by: default avatarDirk Behme <dirk.behme@de.bosch.com>
Reported-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com


Fixes: 6ccbe607 ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent ff9767ba

drivers/i2c/busses/i2c-rcar.c

+12 −5
Original line number Diff line number Diff line
@@ -215,6 +215,14 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) 
	rcar_i2c_write(priv, ICCCR, priv->icccr);

}



static void rcar_i2c_reset_slave(struct rcar_i2c_priv *priv)

{

	rcar_i2c_write(priv, ICSIER, 0);

	rcar_i2c_write(priv, ICSSR, 0);

	rcar_i2c_write(priv, ICSCR, SDBS);

	rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */

}



static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)

{

	int i;
@@ -864,11 +872,8 @@ static int rcar_unreg_slave(struct i2c_client *slave) 


	/* ensure no irq is running before clearing ptr */

	disable_irq(priv->irq);

	rcar_i2c_write(priv, ICSIER, 0);

	rcar_i2c_write(priv, ICSSR, 0);

	rcar_i2c_reset_slave(priv);

	enable_irq(priv->irq);

	rcar_i2c_write(priv, ICSCR, SDBS);

	rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */



	priv->slave = NULL;
@@ -971,7 +976,9 @@ static int rcar_i2c_probe(struct platform_device *pdev) 
	if (ret < 0)

		goto out_pm_put;



	rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */

	/* Bring hardware to known state */

	rcar_i2c_init(priv);

	rcar_i2c_reset_slave(priv);



	if (priv->devtype == I2C_RCAR_GEN3) {

		priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);