Revert "ath79: reset ETH switch for AR9344"

This reverts commit 916af73f.

It was reported this change did not fix the reboot issues on AR9344.

Signed-off-by: David Bauer <mail@david-bauer.net>
(cherry picked from commit 937b5a3e)

target/linux/ath79/patches-6.6/101-reset-ath79-reset-ETH-switch-for-AR9344.patch

-From: David Bauer <mail@david-bauer.net>
-Date: Tue, 2 Jan 2025 19:22:40 +0100
-Subject: [PATCH] reset: ath79: reset ETH switch for AR9344
-
-According to datasheet, on AR9344 the switch and switch analog need to
-be reset first before initiating a full reset.
-
-Resetting these systems fixes spurious reset hangs on Atheros AR9344
-SoCs.
-
-Link: https://github.com/freifunk-gluon/gluon/issues/2904
-
-Signed-off-by: David Bauer <mail@david-bauer.net>
-
---- a/drivers/reset/reset-ath79.c
-+++ b/drivers/reset/reset-ath79.c
-@@ -12,8 +12,11 @@
- #include <linux/platform_device.h>
- #include <linux/reset-controller.h>
- #include <linux/reboot.h>
-+#include <linux/delay.h>
-+#include <linux/of.h>
- 
- struct ath79_reset {
-+	struct platform_device *pdev;
- 	struct reset_controller_dev rcdev;
- 	struct notifier_block restart_nb;
- 	void __iomem *base;
-@@ -21,16 +24,13 @@ struct ath79_reset {
- };
- 
- #define FULL_CHIP_RESET 24
-+#define ETH_SWITCH_RESET 8
-+#define ETH_SWITCH_ARESET 12
- 
--static int ath79_reset_update(struct reset_controller_dev *rcdev,
-+static void __ath79_reset_update_unlocked(struct ath79_reset *ath79_reset,
- 			unsigned long id, bool assert)
- {
--	struct ath79_reset *ath79_reset =
--		container_of(rcdev, struct ath79_reset, rcdev);
--	unsigned long flags;
- 	u32 val;
--
--	spin_lock_irqsave(&ath79_reset->lock, flags);
- 	val = readl(ath79_reset->base);
- 	if (assert)
- 		val |= BIT(id);
-@@ -39,6 +39,17 @@ static int ath79_reset_update(struct res
- 	writel(val, ath79_reset->base);
- 	/* Flush cache */
- 	readl(ath79_reset->base);
-+}
-+
-+static int ath79_reset_update(struct reset_controller_dev *rcdev,
-+			unsigned long id, bool assert)
-+{
-+	struct ath79_reset *ath79_reset =
-+		container_of(rcdev, struct ath79_reset, rcdev);
-+	unsigned long flags;
-+
-+	spin_lock_irqsave(&ath79_reset->lock, flags);
-+	__ath79_reset_update_unlocked(ath79_reset, id, assert);
- 	spin_unlock_irqrestore(&ath79_reset->lock, flags);
- 
- 	return 0;
-@@ -79,8 +90,27 @@ static int ath79_reset_restart_handler(s
- {
- 	struct ath79_reset *ath79_reset =
- 		container_of(nb, struct ath79_reset, restart_nb);
-+	unsigned long flags;
- 
--	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);
-+	spin_lock_irqsave(&ath79_reset->lock, flags);
-+
-+	if (of_device_is_compatible(ath79_reset->pdev->dev.of_node, "qca,ar9340-reset")) {
-+		/**
-+		 * AR9344 has been observed to hang on reboot in rare cases.
-+		 *
-+		 * Datasheet states to reset the ETH switch systems before asserting
-+		 * full chip reset. See page 111 of the AR9344 datasheet.
-+		 */
-+		__ath79_reset_update_unlocked(ath79_reset, ETH_SWITCH_RESET, true);
-+		mdelay(10);
-+		__ath79_reset_update_unlocked(ath79_reset, ETH_SWITCH_ARESET, true);
-+		mdelay(10);
-+	}
-+
-+	__ath79_reset_update_unlocked(ath79_reset, FULL_CHIP_RESET, true);
-+	mdelay(10);
-+
-+	spin_unlock_irqrestore(&ath79_reset->lock, flags);
- 
- 	return NOTIFY_DONE;
- }
-@@ -95,6 +125,8 @@ static int ath79_reset_probe(struct plat
- 	if (!ath79_reset)
- 		return -ENOMEM;
- 
-+	ath79_reset->pdev = pdev;
-+
- 	ath79_reset->base = devm_platform_ioremap_resource(pdev, 0);
- 	if (IS_ERR(ath79_reset->base))
- 		return PTR_ERR(ath79_reset->base);