From 0cb69292622e3530a72d3173d78c484c8f4d3eab Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Fri, 11 Jan 2019 17:31:07 -0800
Subject: [PATCH] soc: bcm: bcm2835-pm: Add support for 2711.

Without the actual power management part any more, there's a lot less
to set up for V3D.  We just need to clear the RSTN field for the power
domain, and expose the reset controller for toggling it again.

This is definitely incomplete -- the old ISP and H264 is in the old
bridge, but since we have no consumers of it I've just done the
minimum to get V3D working.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/mfd/bcm2835-pm.c        | 11 +++++++++++
 drivers/soc/bcm/bcm2835-power.c | 22 ++++++++++++++++++++++
 include/linux/mfd/bcm2835-pm.h  |  1 +
 3 files changed, 34 insertions(+)

--- a/drivers/mfd/bcm2835-pm.c
+++ b/drivers/mfd/bcm2835-pm.c
@@ -50,6 +50,17 @@ static int bcm2835_pm_probe(struct platf
 	if (ret)
 		return ret;
 
+	/* Map the ARGON ASB regs if present. */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	if (res) {
+		pm->arg_asb = devm_ioremap_resource(dev, res);
+		if (IS_ERR(pm->arg_asb)) {
+			dev_err(dev, "Failed to map ARGON ASB: %ld\n",
+				PTR_ERR(pm->arg_asb));
+			return PTR_ERR(pm->arg_asb);
+		}
+	}
+
 	/* We'll use the presence of the AXI ASB regs in the
 	 * bcm2835-pm binding as the key for whether we can reference
 	 * the full PM register range and support power domains.
--- a/drivers/soc/bcm/bcm2835-power.c
+++ b/drivers/soc/bcm/bcm2835-power.c
@@ -143,6 +143,8 @@ struct bcm2835_power {
 	/* AXI Async bridge registers. */
 	void __iomem		*asb;
 
+	bool is_2711;
+
 	struct genpd_onecell_data pd_xlate;
 	struct bcm2835_power_domain domains[BCM2835_POWER_DOMAIN_COUNT];
 	struct reset_controller_dev reset;
@@ -192,6 +194,10 @@ static int bcm2835_power_power_off(struc
 {
 	struct bcm2835_power *power = pd->power;
 
+	/* 2711 has no power domains above the reset controller. */
+	if (power->is_2711)
+		return 0;
+
 	/* Enable functional isolation */
 	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISFUNC);
 
@@ -213,6 +219,10 @@ static int bcm2835_power_power_on(struct
 	int inrush;
 	bool powok;
 
+	/* 2711 has no power domains above the reset controller. */
+	if (power->is_2711)
+		return 0;
+
 	/* If it was already powered on by the fw, leave it that way. */
 	if (PM_READ(pm_reg) & PM_POWUP)
 		return 0;
@@ -627,6 +637,18 @@ static int bcm2835_power_probe(struct pl
 	power->base = pm->base;
 	power->asb = pm->asb;
 
+	/* 2711 hack: the new ARGON ASB took over V3D, which is our
+	 * only consumer of this driver so far.  The old ASB seems to
+	 * still be present with ISP and H264 bits but no V3D, but I
+	 * don't know if that's real or not.  The V3D is in the same
+	 * place in the new ASB as the old one, so just poke the new
+	 * one for now.
+	 */
+	if (pm->arg_asb) {
+		power->asb = pm->arg_asb;
+		power->is_2711 = true;
+	}
+
 	id = ASB_READ(ASB_AXI_BRDG_ID);
 	if (id != 0x62726467 /* "BRDG" */) {
 		dev_err(dev, "ASB register ID returned 0x%08x\n", id);
--- a/include/linux/mfd/bcm2835-pm.h
+++ b/include/linux/mfd/bcm2835-pm.h
@@ -9,6 +9,7 @@ struct bcm2835_pm {
 	struct device *dev;
 	void __iomem *base;
 	void __iomem *asb;
+	void __iomem *arg_asb;
 };
 
 #endif /* BCM2835_MFD_PM_H */
