staging: wfx: add proper "compatible" string

Add "compatible" string matching "vendor,chip" template and proper
GPIO flags handling. Keep support for old name and reset polarity
for older devicetrees.

Cc: [e-mail] # d3a5bcb4a17f ("gpio: add gpiod_toggle_active_low()")
Cc: [e-mail]
Fixes: 0096214a59a7 ("staging: wfx: add support for I/O access")
Signed-off-by: Michał Mirosław <[e-mail]>
Link: https://lore.kernel.org/r/0e[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/wfx/Documentation/devicetree/bindings/net/wireless/siliabs,wfx.txt

···
 You have to declare the WFxxx chip in your device tree.
 
 Required properties:
- - compatible: Should be "silabs,wfx-spi"
+ - compatible: Should be "silabs,wf200"
  - reg: Chip select address of device
  - spi-max-frequency: Maximum SPI clocking speed of device in Hz
  - interrupts-extended: Should contain interrupt line (interrupt-parent +
···
 Optional properties:
  - reset-gpios: phandle of gpio that will be used to reset chip during probe.
    Without this property, you may encounter issues with warm boot.
+   (Legacy: when compatible == "silabs,wfx-spi", the gpio is inverted.)
 
 Please consult Documentation/devicetree/bindings/spi/spi-bus.txt for optional
 SPI connection related properties,
···
 
 &spi1 {
 	wfx {
-		compatible = "silabs,wfx-spi";
+		compatible = "silabs,wf200";
 		pinctrl-names = "default";
 		pinctrl-0 = <&wfx_irq &wfx_gpios>;
 		interrupts-extended = <&gpio 16 IRQ_TYPE_EDGE_RISING>;
 		wakeup-gpios = <&gpio 12 GPIO_ACTIVE_HIGH>;
-		reset-gpios = <&gpio 13 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
 		reg = <0>;
 		spi-max-frequency = <42000000>;
 	};

drivers/staging/wfx/bus_spi.c

···
 #define SET_WRITE 0x7FFF        /* usage: and operation */
 #define SET_READ 0x8000         /* usage: or operation */
 
+#define WFX_RESET_INVERTED 1
+
 static const struct wfx_platform_data wfx_spi_pdata = {
 	.file_fw = "wfm_wf200",
 	.file_pds = "wf200.pds",
···
 	if (!bus->gpio_reset) {
 		dev_warn(&func->dev, "try to load firmware anyway\n");
 	} else {
-		gpiod_set_value(bus->gpio_reset, 0);
-		udelay(100);
+		if (spi_get_device_id(func)->driver_data & WFX_RESET_INVERTED)
+			gpiod_toggle_active_low(bus->gpio_reset);
 		gpiod_set_value(bus->gpio_reset, 1);
+		udelay(100);
+		gpiod_set_value(bus->gpio_reset, 0);
 		udelay(2000);
 	}
 
···
  * stripped.
  */
 static const struct spi_device_id wfx_spi_id[] = {
-	{ "wfx-spi", 0 },
+	{ "wfx-spi", WFX_RESET_INVERTED },
+	{ "wf200", 0 },
 	{ },
 };
 MODULE_DEVICE_TABLE(spi, wfx_spi_id);
 
 #ifdef CONFIG_OF
 static const struct of_device_id wfx_spi_of_match[] = {
-	{ .compatible = "silabs,wfx-spi" },
+	{ .compatible = "silabs,wfx-spi", .data = (void *)WFX_RESET_INVERTED },
+	{ .compatible = "silabs,wf200" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, wfx_spi_of_match);