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i2c: rcar: bring hardware to known state when probing

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[ 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: Dirk Behme <dirk.behme@de.bosch.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/r/20240702045535.2000393-1-dirk.behme@de.bosch.com
Fixes: 6ccbe607132b ("i2c: add Renesas R-Car I2C driver")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit a291702b35433e4948476b79c034a21fd2b5ebc8)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
This commit is contained in:
Wolfram Sang 2024-07-07 10:28:46 +02:00 committed by Vegard Nossum
parent 2a8372159b
commit e0aa415e86
1 changed files with 12 additions and 5 deletions
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17
drivers/i2c/busses/i2c-rcar.c
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@ -173,6 +173,14 @@ 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;
@ -818,11 +826,8 @@ 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;
@ -919,7 +924,9 @@ 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);