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i2c: muxes: pca954x: Fix broken reset-gpio usage

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Revert commit 690de2902d ("i2c: muxes: pca954x: Use reset controller
only") and its dependent commit 94c2967764 ("i2c: muxes: pca954x:
Reset if (de)select fails") because the first breaks all users of the
driver, by requiring a completely optional reset-gpio driver.  These
commits cause that mux driver simply stops working when optional
reset-gpio is not included, but that reset-gpio is not pulled anyhow.

Driver cannot remove legacy reset-gpios handling.

Fixes: 690de2902d ("i2c: muxes: pca954x: Use reset controller only")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
This commit is contained in:
Krzysztof Kozlowski
2025-11-03 16:19:06 +01:00
committed by Wolfram Sang
parent 6146a0f1df
commit 6a0dddc53f
1 changed files with 23 additions and 27 deletions
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50
drivers/i2c/muxes/i2c-mux-pca954x.c
View File

@@ -118,6 +118,7 @@ struct pca954x {
raw_spinlock_t lock;
struct regulator *supply;
struct gpio_desc *reset_gpio;
struct reset_control *reset_cont;
};
@@ -315,25 +316,6 @@ static u8 pca954x_regval(struct pca954x *data, u8 chan)
return 1 << chan;
}
static void pca954x_reset_assert(struct pca954x *data)
{
if (data->reset_cont)
reset_control_assert(data->reset_cont);
}
static void pca954x_reset_deassert(struct pca954x *data)
{
if (data->reset_cont)
reset_control_deassert(data->reset_cont);
}
static void pca954x_reset_mux(struct pca954x *data)
{
pca954x_reset_assert(data);
udelay(1);
pca954x_reset_deassert(data);
}
static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
{
struct pca954x *data = i2c_mux_priv(muxc);
@@ -347,8 +329,6 @@ static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
ret = pca954x_reg_write(muxc->parent, client, regval);
data->last_chan = ret < 0 ? 0 : regval;
}
if (ret == -ETIMEDOUT && data->reset_cont)
pca954x_reset_mux(data);
return ret;
}
@@ -358,7 +338,6 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
struct pca954x *data = i2c_mux_priv(muxc);
struct i2c_client *client = data->client;
s32 idle_state;
int ret = 0;
idle_state = READ_ONCE(data->idle_state);
if (idle_state >= 0)
@@ -368,10 +347,8 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
if (idle_state == MUX_IDLE_DISCONNECT) {
/* Deselect active channel */
data->last_chan = 0;
ret = pca954x_reg_write(muxc->parent, client,
data->last_chan);
if (ret == -ETIMEDOUT && data->reset_cont)
pca954x_reset_mux(data);
return pca954x_reg_write(muxc->parent, client,
data->last_chan);
}
/* otherwise leave as-is */
@@ -550,10 +527,29 @@ static int pca954x_get_reset(struct device *dev, struct pca954x *data)
if (IS_ERR(data->reset_cont))
return dev_err_probe(dev, PTR_ERR(data->reset_cont),
"Failed to get reset\n");
else if (data->reset_cont)
return 0;
/*
* fallback to legacy reset-gpios
*/
data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(data->reset_gpio)) {
return dev_err_probe(dev, PTR_ERR(data->reset_gpio),
"Failed to get reset gpio");
}
return 0;
}
static void pca954x_reset_deassert(struct pca954x *data)
{
if (data->reset_cont)
reset_control_deassert(data->reset_cont);
else
gpiod_set_value_cansleep(data->reset_gpio, 0);
}
/*
* I2C init/probing/exit functions
*/
@@ -593,7 +589,7 @@ static int pca954x_probe(struct i2c_client *client)
if (ret)
goto fail_cleanup;
if (data->reset_cont) {
if (data->reset_cont || data->reset_gpio) {
udelay(1);
pca954x_reset_deassert(data);
/* Give the chip some time to recover. */