Hi!
On 2020-10-10 00:43, Evan Green wrote:
> 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,
This is so since the I2C gpio-mux predates the "i2c-bus" sub-node of
I2C controllers. At that time *all* sub-nodes of I2C controllers
represented I2C client device, IIUC. With that knowledge, you could
perhaps rephrase the above?
Also, a nit below.
> 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@xxxxxxxxxxxx>
> ---
>
> 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;
I would write that as
values[i] = adr;
Cheers,
Peter
> +
> + } 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 {
>
