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Commit 8aacd901 authored by Peter Rosin's avatar Peter Rosin Committed by Wolfram Sang
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i2c: i2c-arb-gpio-challenge: convert to use an explicit i2c mux core 



Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.

Signed-off-by: default avatarPeter Rosin <peda@axentia.se>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 4bbe7fb0

drivers/i2c/muxes/i2c-arb-gpio-challenge.c

+20 −27
Original line number Diff line number Diff line
@@ -28,8 +28,6 @@ 
/**

 * struct i2c_arbitrator_data - Driver data for I2C arbitrator

 *

 * @parent: Parent adapter

 * @child: Child bus

 * @our_gpio: GPIO we'll use to claim.

 * @our_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO ==

 *   this then consider it released.
@@ -42,8 +40,6 @@ 
 */



struct i2c_arbitrator_data {

	struct i2c_adapter *parent;

	struct i2c_adapter *child;

	int our_gpio;

	int our_gpio_release;

	int their_gpio;
@@ -59,9 +55,9 @@ struct i2c_arbitrator_data { 
 *

 * Use the GPIO-based signalling protocol; return -EBUSY if we fail.

 */

static int i2c_arbitrator_select(struct i2c_adapter *adap, void *data, u32 chan)

static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan)

{

	const struct i2c_arbitrator_data *arb = data;

	const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);

	unsigned long stop_retry, stop_time;



	/* Start a round of trying to claim the bus */
@@ -93,7 +89,7 @@ static int i2c_arbitrator_select(struct i2c_adapter *adap, void *data, u32 chan) 
	/* Give up, release our claim */

	gpio_set_value(arb->our_gpio, arb->our_gpio_release);

	udelay(arb->slew_delay_us);

	dev_err(&adap->dev, "Could not claim bus, timeout\n");

	dev_err(muxc->dev, "Could not claim bus, timeout\n");

	return -EBUSY;

}
@@ -102,10 +98,9 @@ static int i2c_arbitrator_select(struct i2c_adapter *adap, void *data, u32 chan) 
 *

 * Release the I2C bus using the GPIO-based signalling protocol.

 */

static int i2c_arbitrator_deselect(struct i2c_adapter *adap, void *data,

				   u32 chan)

static int i2c_arbitrator_deselect(struct i2c_mux_core *muxc, u32 chan)

{

	const struct i2c_arbitrator_data *arb = data;

	const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);



	/* Release the bus and wait for the other master to notice */

	gpio_set_value(arb->our_gpio, arb->our_gpio_release);
@@ -119,6 +114,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) 
	struct device *dev = &pdev->dev;

	struct device_node *np = dev->of_node;

	struct device_node *parent_np;

	struct i2c_mux_core *muxc;

	struct i2c_arbitrator_data *arb;

	enum of_gpio_flags gpio_flags;

	unsigned long out_init;
@@ -134,12 +130,13 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) 
		return -EINVAL;

	}



	arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);

	if (!arb) {

		dev_err(dev, "Cannot allocate i2c_arbitrator_data\n");

	muxc = i2c_mux_alloc(NULL, dev, 1, sizeof(*arb), 0,

			     i2c_arbitrator_select, i2c_arbitrator_deselect);

	if (!muxc)

		return -ENOMEM;

	}

	platform_set_drvdata(pdev, arb);

	arb = i2c_mux_priv(muxc);



	platform_set_drvdata(pdev, muxc);



	/* Request GPIOs */

	ret = of_get_named_gpio_flags(np, "our-claim-gpio", 0, &gpio_flags);
@@ -196,21 +193,18 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) 
		dev_err(dev, "Cannot parse i2c-parent\n");

		return -EINVAL;

	}

	arb->parent = of_get_i2c_adapter_by_node(parent_np);

	muxc->parent = of_get_i2c_adapter_by_node(parent_np);

	of_node_put(parent_np);

	if (!arb->parent) {

	if (!muxc->parent) {

		dev_err(dev, "Cannot find parent bus\n");

		return -EPROBE_DEFER;

	}



	/* Actually add the mux adapter */

	arb->child = i2c_add_mux_adapter(arb->parent, dev, arb, 0, 0, 0,

					 i2c_arbitrator_select,

					 i2c_arbitrator_deselect);

	if (!arb->child) {

	ret = i2c_mux_add_adapter(muxc, 0, 0, 0);

	if (ret) {

		dev_err(dev, "Failed to add adapter\n");

		ret = -ENODEV;

		i2c_put_adapter(arb->parent);

		i2c_put_adapter(muxc->parent);

	}



	return ret;
@@ -218,11 +212,10 @@ static int i2c_arbitrator_probe(struct platform_device *pdev) 


static int i2c_arbitrator_remove(struct platform_device *pdev)

{

	struct i2c_arbitrator_data *arb = platform_get_drvdata(pdev);



	i2c_del_mux_adapter(arb->child);

	i2c_put_adapter(arb->parent);

	struct i2c_mux_core *muxc = platform_get_drvdata(pdev);



	i2c_mux_del_adapters(muxc);

	i2c_put_adapter(muxc->parent);

	return 0;

}