brcm80211: brcmsmac: Move LEDs to GPIO descriptors

The code in the BRCM80211 BRCMSMAC driver is using the legacy
GPIO API to to a complex check of the validity of the base of
the GPIO chip and whether it is present at all and then adding
an offset to the base of the chip.

Use the existing function to obtain a GPIO line internally
from a GPIO chip so we can use the offset directly and
modernize the code to use GPIO descriptors instead of integers
from the global GPIO numberspace.

Cc: Wright Feng <wright.feng@cypress.com>
Cc: Frank Kao <frank.kao@cypress.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200711210150.4943-1-linus.walleij@linaro.org

drivers/net/wireless/broadcom/brcm80211/brcmsmac/led.c

 // SPDX-License-Identifier: GPL-2.0
 #include <net/mac80211.h>
 #include <linux/bcma/bcma_driver_chipcommon.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/consumer.h>
 
 #include "mac80211_if.h"
 #include "pub.h"
@@ -19,16 +21,13 @@
 
 static void brcms_radio_led_ctrl(struct brcms_info *wl, bool state)
 {
-	if (wl->radio_led.gpio == -1)
+	if (!wl->radio_led.gpiod)
 		return;
 
-	if (wl->radio_led.active_low)
-		state = !state;
-
 	if (state)
-		gpio_set_value(wl->radio_led.gpio, 1);
+		gpiod_set_value(wl->radio_led.gpiod, 1);
 	else
-		gpio_set_value(wl->radio_led.gpio, 0);
+		gpiod_set_value(wl->radio_led.gpiod, 0);
 }
 
 
@@ -45,8 +44,8 @@ void brcms_led_unregister(struct brcms_info *wl)
 {
 	if (wl->led_dev.dev)
 		led_classdev_unregister(&wl->led_dev);
-	if (wl->radio_led.gpio != -1)
-		gpio_free(wl->radio_led.gpio);
+	if (wl->radio_led.gpiod)
+		gpiochip_free_own_desc(wl->radio_led.gpiod);
 }
 
 int brcms_led_register(struct brcms_info *wl)
@@ -61,12 +60,8 @@ int brcms_led_register(struct brcms_info *wl)
 		&sprom->gpio1,
 		&sprom->gpio2,
 		&sprom->gpio3 };
-	unsigned gpio = -1;
-	bool active_low = false;
-
-	/* none by default */
-	radio_led->gpio = -1;
-	radio_led->active_low = false;
+	int hwnum = -1;
+	enum gpio_lookup_flags lflags = GPIO_ACTIVE_HIGH;
 
 	if (!bcma_gpio || !gpio_is_valid(bcma_gpio->base))
 		return -ENODEV;
@@ -75,30 +70,26 @@ int brcms_led_register(struct brcms_info *wl)
 	for (i = 0; i < BRCMS_LED_NO; i++) {
 		u8 led = *leds[i];
 		if ((led & BRCMS_LED_BEH_MASK) == BRCMS_LED_RADIO) {
-			gpio = bcma_gpio->base + i;
+			hwnum = i;
 			if (led & BRCMS_LED_AL_MASK)
-				active_low = true;
+				lflags = GPIO_ACTIVE_LOW;
 			break;
 		}
 	}
 
-	if (gpio == -1 || !gpio_is_valid(gpio))
+	/* No LED, bail out */
+	if (hwnum == -1)
 		return -ENODEV;
 
-	/* request and configure LED gpio */
-	err = gpio_request_one(gpio,
-				active_low ? GPIOF_OUT_INIT_HIGH
-					: GPIOF_OUT_INIT_LOW,
-				"radio on");
-	if (err) {
-		wiphy_err(wl->wiphy, "requesting led gpio %d failed (err: %d)\n",
-			  gpio, err);
-		return err;
-	}
-	err = gpio_direction_output(gpio, 1);
-	if (err) {
-		wiphy_err(wl->wiphy, "cannot set led gpio %d to output (err: %d)\n",
-			  gpio, err);
+	/* Try to obtain this LED GPIO line */
+	radio_led->gpiod = gpiochip_request_own_desc(bcma_gpio, hwnum,
+						     "radio on", lflags,
+						     GPIOD_OUT_LOW);
+
+	if (IS_ERR(radio_led->gpiod)) {
+		err = PTR_ERR(radio_led->gpiod);
+		wiphy_err(wl->wiphy, "requesting led GPIO failed (err: %d)\n",
+			  err);
 		return err;
 	}
 
@@ -117,11 +108,8 @@ int brcms_led_register(struct brcms_info *wl)
 		return err;
 	}
 
-	wiphy_info(wl->wiphy, "registered radio enabled led device: %s gpio: %d\n",
-		   wl->radio_led.name,
-		   gpio);
-	radio_led->gpio = gpio;
-	radio_led->active_low = active_low;
+	wiphy_info(wl->wiphy, "registered radio enabled led device: %s\n",
+		   wl->radio_led.name);
 
 	return 0;
 }

drivers/net/wireless/broadcom/brcm80211/brcmsmac/led.h

@@ -16,10 +16,12 @@
 
 #ifndef _BRCM_LED_H_
 #define _BRCM_LED_H_
+
+struct gpio_desc;
+
 struct brcms_led {
 	char name[32];
-	unsigned gpio;
-	bool active_low;
+	struct gpio_desc *gpiod;
 };
 
 #ifdef CONFIG_BCMA_DRIVER_GPIO