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Message-Id: <20201016152454.v3.2.Idef164c23d326f5e5edecfc5d3eb2a68fcf18be1@changeid>
Date: Fri, 16 Oct 2020 15:25:23 -0700
From: Evan Green <evgreen@...omium.org>
To: Peter Rosin <peda@...ntia.se>
Cc: Wolfram Sang <wsa@...nel.org>,
Randy Dunlap <rdunlap@...radead.org>,
Evan Green <evgreen@...omium.org>,
Peter Korsgaard <peter.korsgaard@...co.com>,
linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v3 2/2] i2c: i2c-mux-gpio: Enable this driver in ACPI land
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@...omium.org>
---
Changes in v3:
- Update commit message again (Peter)
- Added missing \n (Peter)
- adr64 overflow check (Peter)
- Don't initialize child (Peter)
- Limit scope of dev_handle (Peter)
Changes in v2:
- Make it compile properly when !CONFIG_ACPI (Randy)
- Update commit message regarding i2c-parent (Peter)
drivers/i2c/muxes/i2c-mux-gpio.c | 107 +++++++++++++++++++++++--------
1 file changed, 79 insertions(+), 28 deletions(-)
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index caaa782b50d83..bac415a52b780 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -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 (is_of_node(dev->fwnode)) {
+ if (!np)
+ return -ENODEV;
- 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 = 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_np = of_parse_phandle(np, "i2c-parent", 0);
- if (!adapter_np) {
- dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
- return -ENODEV;
+ 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 {
--
2.26.2
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