staging: wfx: Get descriptors for GPIOs

The code has the functionality to insert the GPIO lines using
the global GPIO numbers through module parameters.

As we are clearly deprecating the use of global GPIO numbers
look up the GPIO descriptors from the device instead. This
usually falls back to device hardware descriptions using e.g.
device tree or ACPI. This device clearly supports device
tree when used over SPI for example.

For example, this can be supplied in the device tree like so:

  wfx@0x01 {
      compatible = "silabs,wf200";
      reset-gpios = <&gpio0 1>;
      wakeup-gpios = <&gpio0 2>;
  };

Cc: Jérôme Pouiller <jerome.pouiller@silabs.com>
Reviewed-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200703130756.514868-1-linus.walleij@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/bus_spi.c

@@ -8,7 +8,6 @@
  */
 #include <linux/module.h>
 #include <linux/delay.h>
-#include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/spi/spi.h>
 #include <linux/interrupt.h>
@@ -21,10 +20,6 @@
 #include "main.h"
 #include "bh.h"
 
-static int gpio_reset = -2;
-module_param(gpio_reset, int, 0644);
-MODULE_PARM_DESC(gpio_reset, "gpio number for reset. -1 for none.");
-
 #define SET_WRITE 0x7FFF        /* usage: and operation */
 #define SET_READ 0x8000         /* usage: or operation */
 
@@ -211,10 +206,15 @@ static int wfx_spi_probe(struct spi_device *func)
 		bus->need_swab = true;
 	spi_set_drvdata(func, bus);
 
-	bus->gpio_reset = wfx_get_gpio(&func->dev, gpio_reset, "reset");
+	bus->gpio_reset = devm_gpiod_get_optional(&func->dev, "reset",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(bus->gpio_reset))
+		return PTR_ERR(bus->gpio_reset);
 	if (!bus->gpio_reset) {
-		dev_warn(&func->dev, "try to load firmware anyway\n");
+		dev_warn(&func->dev,
+			 "gpio reset is not defined, trying to load firmware anyway\n");
 	} else {
+		gpiod_set_consumer_name(bus->gpio_reset, "wfx reset");
 		if (spi_get_device_id(func)->driver_data & WFX_RESET_INVERTED)
 			gpiod_toggle_active_low(bus->gpio_reset);
 		gpiod_set_value_cansleep(bus->gpio_reset, 1);

drivers/staging/wfx/main.c

@@ -13,7 +13,6 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_net.h>
-#include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/mmc/sdio_func.h>
 #include <linux/spi/spi.h>
@@ -41,10 +40,6 @@ MODULE_DESCRIPTION("Silicon Labs 802.11 Wireless LAN driver for WFx");
 MODULE_AUTHOR("Jérôme Pouiller <jerome.pouiller@silabs.com>");
 MODULE_LICENSE("GPL");
 
-static int gpio_wakeup = -2;
-module_param(gpio_wakeup, int, 0644);
-MODULE_PARM_DESC(gpio_wakeup, "gpio number for wakeup. -1 for none.");
-
 #define RATETAB_ENT(_rate, _rateid, _flags) { \
 	.bitrate  = (_rate),   \
 	.hw_value = (_rateid), \
@@ -170,38 +165,6 @@ bool wfx_api_older_than(struct wfx_dev *wdev, int major, int minor)
 	return false;
 }
 
-struct gpio_desc *wfx_get_gpio(struct device *dev,
-			       int override, const char *label)
-{
-	struct gpio_desc *ret;
-	char label_buf[256];
-
-	if (override >= 0) {
-		snprintf(label_buf, sizeof(label_buf), "wfx_%s", label);
-		ret = ERR_PTR(devm_gpio_request_one(dev, override,
-						    GPIOF_OUT_INIT_LOW,
-						    label_buf));
-		if (!ret)
-			ret = gpio_to_desc(override);
-	} else if (override == -1) {
-		ret = NULL;
-	} else {
-		ret = devm_gpiod_get(dev, label, GPIOD_OUT_LOW);
-	}
-	if (IS_ERR_OR_NULL(ret)) {
-		if (!ret || PTR_ERR(ret) == -ENOENT)
-			dev_warn(dev, "gpio %s is not defined\n", label);
-		else
-			dev_warn(dev, "error while requesting gpio %s\n",
-				 label);
-		ret = NULL;
-	} else {
-		dev_dbg(dev, "using gpio %d for %s\n",
-			desc_to_gpio(ret), label);
-	}
-	return ret;
-}
-
 /* NOTE: wfx_send_pds() destroy buf */
 int wfx_send_pds(struct wfx_dev *wdev, u8 *buf, size_t len)
 {
@@ -340,7 +303,12 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 	memcpy(&wdev->pdata, pdata, sizeof(*pdata));
 	of_property_read_string(dev->of_node, "config-file",
 				&wdev->pdata.file_pds);
-	wdev->pdata.gpio_wakeup = wfx_get_gpio(dev, gpio_wakeup, "wakeup");
+	wdev->pdata.gpio_wakeup = devm_gpiod_get_optional(dev, "wakeup",
+							  GPIOD_OUT_LOW);
+	if (IS_ERR(wdev->pdata.gpio_wakeup))
+		return ERR_CAST(wdev->pdata.gpio_wakeup);
+	if (wdev->pdata.gpio_wakeup)
+		gpiod_set_consumer_name(wdev->pdata.gpio_wakeup, "wfx wakeup");
 	wfx_sl_fill_pdata(dev, &wdev->pdata);
 
 	mutex_init(&wdev->conf_mutex);
@@ -444,8 +412,7 @@ int wfx_probe(struct wfx_dev *wdev)
 	wdev->pdata.gpio_wakeup = gpio_saved;
 	if (wdev->pdata.gpio_wakeup) {
 		dev_dbg(wdev->dev,
-			"enable 'quiescent' power mode with gpio %d and PDS file %s\n",
-			desc_to_gpio(wdev->pdata.gpio_wakeup),
+			"enable 'quiescent' power mode with wakeup GPIO and PDS file %s\n",
 			wdev->pdata.file_pds);
 		gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 1);
 		control_reg_write(wdev, 0);

drivers/staging/wfx/main.h

@@ -38,8 +38,6 @@ struct wfx_dev *wfx_init_common(struct device *dev,
 int wfx_probe(struct wfx_dev *wdev);
 void wfx_release(struct wfx_dev *wdev);
 
-struct gpio_desc *wfx_get_gpio(struct device *dev, int override,
-			       const char *label);
 bool wfx_api_older_than(struct wfx_dev *wdev, int major, int minor);
 int wfx_send_pds(struct wfx_dev *wdev, u8 *buf, size_t len);