[v3,1/2] i2c: rcar: reset controller is mandatory for Gen3+
Commit Message
Initially, we only needed a reset controller to make sure RXDMA works at
least once per transfer. Meanwhile, documentation has been updated. It
now says that a reset has to be performed prior every transaction, even
if it is non-DMA. So, make the reset controller a requirement instead of
being optional. And bail out if resetting fails.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
Change since v2:
* properly bail out on errors using goto
To make that easier, the reset controller is now probed after the
handling of pm_runtime_put() is determined
drivers/i2c/busses/i2c-rcar.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)
Comments
On Thu, 21 Sep 2023, Wolfram Sang wrote:
> Initially, we only needed a reset controller to make sure RXDMA works at
> least once per transfer. Meanwhile, documentation has been updated. It
> now says that a reset has to be performed prior every transaction, even
> if it is non-DMA. So, make the reset controller a requirement instead of
> being optional. And bail out if resetting fails.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> Change since v2:
> * properly bail out on errors using goto
> To make that easier, the reset controller is now probed after the
> handling of pm_runtime_put() is determined
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
On Thu, Sep 21, 2023 at 02:53:49PM +0200, Wolfram Sang wrote:
> Initially, we only needed a reset controller to make sure RXDMA works at
> least once per transfer. Meanwhile, documentation has been updated. It
> now says that a reset has to be performed prior every transaction, even
> if it is non-DMA. So, make the reset controller a requirement instead of
> being optional. And bail out if resetting fails.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Applied to for-next, thanks!
@@ -838,12 +838,10 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
/* Gen3 needs a reset before allowing RXDMA once */
if (priv->devtype == I2C_RCAR_GEN3) {
- priv->flags |= ID_P_NO_RXDMA;
- if (!IS_ERR(priv->rstc)) {
- ret = rcar_i2c_do_reset(priv);
- if (ret == 0)
- priv->flags &= ~ID_P_NO_RXDMA;
- }
+ priv->flags &= ~ID_P_NO_RXDMA;
+ ret = rcar_i2c_do_reset(priv);
+ if (ret)
+ goto out;
}
rcar_i2c_init(priv);
@@ -1094,15 +1092,6 @@ static int rcar_i2c_probe(struct platform_device *pdev)
irqhandler = rcar_i2c_gen2_irq;
}
- if (priv->devtype == I2C_RCAR_GEN3) {
- priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
- if (!IS_ERR(priv->rstc)) {
- ret = reset_control_status(priv->rstc);
- if (ret < 0)
- priv->rstc = ERR_PTR(-ENOTSUPP);
- }
- }
-
/* Stay always active when multi-master to keep arbitration working */
if (of_property_read_bool(dev->of_node, "multi-master"))
priv->flags |= ID_P_PM_BLOCKED;
@@ -1112,6 +1101,16 @@ static int rcar_i2c_probe(struct platform_device *pdev)
if (of_property_read_bool(dev->of_node, "smbus"))
priv->flags |= ID_P_HOST_NOTIFY;
+ if (priv->devtype == I2C_RCAR_GEN3) {
+ priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(priv->rstc))
+ goto out_pm_put;
+
+ ret = reset_control_status(priv->rstc);
+ if (ret < 0)
+ goto out_pm_put;
+ }
+
ret = platform_get_irq(pdev, 0);
if (ret < 0)
goto out_pm_put;