Commit 6a0dddc5 authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Wolfram Sang
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i2c: muxes: pca954x: Fix broken reset-gpio usage 



Revert commit 690de290 ("i2c: muxes: pca954x: Use reset controller
only") and its dependent commit 94c29677 ("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: 690de290 ("i2c: muxes: pca954x: Use reset controller only")
Signed-off-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
parent 6146a0f1

drivers/i2c/muxes/i2c-mux-pca954x.c

+23 −27
Original line number Diff line number Diff line
@@ -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,

		return pca954x_reg_write(muxc->parent, client,

					 data->last_chan);

		if (ret == -ETIMEDOUT && data->reset_cont)

			pca954x_reset_mux(data);

	}



	/* 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. */