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Subject[PATCH] i2c: i2c-mux-gpio: Enable this driver in ACPI land
Date
Enable i2c-mux-gpio devices to be defined via ACPI. The idle-state
property translates directly to a fwnode_property_*() call. The child
reg property translates naturally into _ADR in ACPI.

The i2c-parent is a little trickier, since of's phandle definition
suggests the i2c mux could live in a completely different part of
the tree than its upstream i2c controller. For now in ACPI,
just assume that the i2c-mux-gpio device will always be a direct
child of the i2c controller. If the additional flexibility of
defining muxes in wildly different locations from their parent
controllers is required, it can be added later.

Signed-off-by: Evan Green <evgreen@chromium.org>
---

drivers/i2c/muxes/i2c-mux-gpio.c | 77 +++++++++++++++++++++-----------
1 file changed, 50 insertions(+), 27 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index 4effe563e9e8d..f195e95e8a037 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -49,34 +49,46 @@ static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan)
return 0;
}

-#ifdef CONFIG_OF
-static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
- struct platform_device *pdev)
+static int i2c_mux_gpio_probe_fw(struct gpiomux *mux,
+ struct platform_device *pdev)
{
- struct device_node *np = pdev->dev.of_node;
- struct device_node *adapter_np, *child;
- struct i2c_adapter *adapter;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ acpi_handle dev_handle;
+ struct device_node *adapter_np;
+ struct i2c_adapter *adapter = NULL;
+ struct fwnode_handle *child = NULL;
unsigned *values;
int i = 0;

- if (!np)
- return -ENODEV;
+ if (is_of_node(dev->fwnode)) {
+ if (!np)
+ return -ENODEV;

- adapter_np = of_parse_phandle(np, "i2c-parent", 0);
- if (!adapter_np) {
- dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
- return -ENODEV;
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ of_node_put(adapter_np);
+
+ } else if (is_acpi_node(dev->fwnode)) {
+ /*
+ * In ACPI land the mux should be a direct child of the i2c
+ * bus it muxes.
+ */
+ dev_handle = ACPI_HANDLE(dev->parent);
+ adapter = i2c_acpi_find_adapter_by_handle(dev_handle);
}
- adapter = of_find_i2c_adapter_by_node(adapter_np);
- of_node_put(adapter_np);
+
if (!adapter)
return -EPROBE_DEFER;

mux->data.parent = i2c_adapter_id(adapter);
put_device(&adapter->dev);

- mux->data.n_values = of_get_child_count(np);
-
+ mux->data.n_values = device_get_child_node_count(dev);
values = devm_kcalloc(&pdev->dev,
mux->data.n_values, sizeof(*mux->data.values),
GFP_KERNEL);
@@ -85,24 +97,35 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
return -ENOMEM;
}

- for_each_child_of_node(np, child) {
- of_property_read_u32(child, "reg", values + i);
+ device_for_each_child_node(dev, child) {
+ if (is_of_node(child)) {
+ fwnode_property_read_u32(child, "reg", values + i);
+
+ } else if (is_acpi_node(child)) {
+ unsigned long long adr;
+ acpi_status status;
+
+ status = acpi_evaluate_integer(ACPI_HANDLE_FWNODE(child),
+ METHOD_NAME__ADR,
+ NULL, &adr);
+ if (ACPI_SUCCESS(status)) {
+ *(values + i) = adr;
+
+ } else {
+ dev_err(dev, "Cannot get address");
+ return -EINVAL;
+ }
+ }
+
i++;
}
mux->data.values = values;

- if (of_property_read_u32(np, "idle-state", &mux->data.idle))
+ if (fwnode_property_read_u32(dev->fwnode, "idle-state", &mux->data.idle))
mux->data.idle = I2C_MUX_GPIO_NO_IDLE;

return 0;
}
-#else
-static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
- struct platform_device *pdev)
-{
- return 0;
-}
-#endif

static int i2c_mux_gpio_probe(struct platform_device *pdev)
{
@@ -118,7 +141,7 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
return -ENOMEM;

if (!dev_get_platdata(&pdev->dev)) {
- ret = i2c_mux_gpio_probe_dt(mux, pdev);
+ ret = i2c_mux_gpio_probe_fw(mux, pdev);
if (ret < 0)
return ret;
} else {
--
2.26.2
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