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i2c: i2c-mux-gpio: Enable this driver in ACPI land

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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 binding is a relic from the days when the bindings
dictated that all direct children of an I2C controller had to be I2C
devices. These days that's no longer required. The i2c-mux can sit as a
direct child of its parent controller, which is where it makes the most
sense from a hardware description perspective. For the ACPI
implementation we'll assume that's always how the i2c-mux-gpio is
instantiated.

Signed-off-by: Evan Green <evgreen@chromium.org>
Acked-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This commit is contained in:
Evan Green 2020-11-18 15:40:25 -08:00 committed by Wolfram Sang
parent 19eb29b05c
commit 98b2b712bc
1 changed files with 79 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

107
drivers/i2c/muxes/i2c-mux-gpio.c
View File

@ -49,35 +49,85 @@ 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)
#ifdef CONFIG_ACPI
static int i2c_mux_gpio_get_acpi_adr(struct device *dev,
struct fwnode_handle *fwdev,
unsigned int *adr)
{
unsigned long long adr64;
acpi_status status;
status = acpi_evaluate_integer(ACPI_HANDLE_FWNODE(fwdev),
METHOD_NAME__ADR,
NULL, &adr64);
if (!ACPI_SUCCESS(status)) {
dev_err(dev, "Cannot get address\n");
return -EINVAL;
}
*adr = adr64;
if (*adr != adr64) {
dev_err(dev, "Address out of range\n");
return -ERANGE;
}
return 0;
}
#else
static int i2c_mux_gpio_get_acpi_adr(struct device *dev,
struct fwnode_handle *fwdev,
unsigned int *adr)
{
return -EINVAL;
}
#endif
static int i2c_mux_gpio_probe_fw(struct gpiomux *mux,
struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct device_node *adapter_np, *child;
struct i2c_adapter *adapter;
struct device_node *np = dev->of_node;
struct device_node *adapter_np;
struct i2c_adapter *adapter = NULL;
struct fwnode_handle *child;
unsigned *values;
int i = 0;
int rc, 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.
*/
acpi_handle 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(dev,
mux->data.n_values, sizeof(*mux->data.values),
GFP_KERNEL);
@ -86,24 +136,25 @@ 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)) {
rc = i2c_mux_gpio_get_acpi_adr(dev, child, values + i);
if (rc)
return rc;
}
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)
{
@ -119,7 +170,7 @@ 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 {