[PATCH v7 04/24] i2c: i2c-arb-gpio-challenge: convert to use an explicit i2c mux core

Peter Rosin
2016-04-20T15:19:29Z

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>
---
drivers/i2c/muxes/i2c-arb-gpio-challenge.c | 47 +++++++++++++-----------------
1 file changed, 20 insertions(+), 27 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
index 402e3a6c671a..a90bbc4037dd 100644
--- a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
+++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
@@ -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;
}

--
2.1.4