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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: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Peter Rosin 2016-04-20 08:39:46 +02:00 committed by Wolfram Sang
parent 4bbe7fb0a2
commit 8aacd90166
1 changed files with 20 additions and 27 deletions
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47
drivers/i2c/muxes/i2c-arb-gpio-challenge.c
View File

@ -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;
}