Merge branch 'net-dsa-bcm_sf2-Add-support-for-optional-reset-controller-line'

Florian Fainelli says:

====================
net: dsa: bcm_sf2: Add support for optional reset controller line

This patch series definest the optional reset controller line for the
BCM7445/BCM7278 integrated Ethernet switches and updates the driver to
drive that reset line in lieu of the internal watchdog based reset since
it does not work on BCM7278.

Changes in v2:
- make the reset_control_assert() conditional to BCM7278 in the remove
function as well
====================

Signed-off-by: David S. Miller <[e-mail]>

Documentation/devicetree/bindings/net/brcm,bcm7445-switch-v4.0.txt

···
   Admission Control Block supports reporting the number of packets in-flight in a
   switch queue
 
+- resets: a single phandle and reset identifier pair. See
+  Documentation/devicetree/binding/reset/reset.txt for details.
+
+- reset-names: If the "reset" property is specified, this property should have
+  the value "switch" to denote the switch reset line.
+
 Port subnodes:
 
 Optional properties:

drivers/net/dsa/bcm_sf2.c

···
 {
 	unsigned int timeout = 1000;
 	u32 reg;
+	int ret;
+
+	/* The watchdog reset does not work on 7278, we need to hit the
+	 * "external" reset line through the reset controller.
+	 */
+	if (priv->type == BCM7278_DEVICE_ID && !IS_ERR(priv->rcdev)) {
+		ret = reset_control_assert(priv->rcdev);
+		if (ret)
+			return ret;
+
+		return reset_control_deassert(priv->rcdev);
+	}
 
 	reg = core_readl(priv, CORE_WATCHDOG_CTRL);
 	reg |= SOFTWARE_RESET | EN_CHIP_RST | EN_SW_RESET;
···
 	priv->core_reg_align = data->core_reg_align;
 	priv->num_cfp_rules = data->num_cfp_rules;
 
+	priv->rcdev = devm_reset_control_get_optional_exclusive(&pdev->dev,
+								"switch");
+	if (PTR_ERR(priv->rcdev) == -EPROBE_DEFER)
+		return PTR_ERR(priv->rcdev);
+
 	/* Auto-detection using standard registers will not work, so
 	 * provide an indication of what kind of device we are for
 	 * b53_common to work with
···
 	/* Disable all ports and interrupts */
 	bcm_sf2_sw_suspend(priv->dev->ds);
 	bcm_sf2_mdio_unregister(priv);
+	if (priv->type == BCM7278_DEVICE_ID && !IS_ERR(priv->rcdev))
+		reset_control_assert(priv->rcdev);
 
 	return 0;
 }

drivers/net/dsa/bcm_sf2.h

···
 #include <linux/types.h>
 #include <linux/bitops.h>
 #include <linux/if_vlan.h>
+#include <linux/reset.h>
 
 #include <net/dsa.h>
 
···
 	void __iomem			*intrl2_1;
 	void __iomem			*fcb;
 	void __iomem			*acb;
+
+	struct reset_control		*rcdev;
 
 	/* Register offsets indirection tables */
 	u32 				type;