clk: mmp2: Add support for power islands

Apart from the clocks and resets, the PMU hardware also controls power
to peripherals that are on separate power islands. On MMP2, that's the
GC860 GPU and the SSPA audio interface, while on MMP3 also the camera
interface is on a separate island, along with the pair of GC2000 and GC300
GPUs and the SSPA.

Signed-off-by: Lubomir Rintel <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Stephen Boyd <[e-mail]>

arch/arm/mach-mmp/Kconfig

···
 	select PINCTRL_SINGLE
 	select ARCH_HAS_RESET_CONTROLLER
 	select CPU_PJ4
+	select PM_GENERIC_DOMAINS if PM
+	select PM_GENERIC_DOMAINS_OF if PM && OF
 	help
 	  Include support for Marvell MMP2 based platforms using
 	  the device tree.

drivers/clk/mmp/Makefile

···
 obj-$(CONFIG_RESET_CONTROLLER) += reset.o
 
 obj-$(CONFIG_MACH_MMP_DT) += clk-of-pxa168.o clk-of-pxa910.o
-obj-$(CONFIG_COMMON_CLK_MMP2) += clk-of-mmp2.o clk-pll.o
+obj-$(CONFIG_COMMON_CLK_MMP2) += clk-of-mmp2.o clk-pll.o pwr-island.o
 
 obj-$(CONFIG_CPU_PXA168) += clk-pxa168.o
 obj-$(CONFIG_CPU_PXA910) += clk-pxa910.o

drivers/clk/mmp/clk-of-mmp2.c

···
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/of_address.h>
+#include <linux/clk.h>
 
 #include <dt-bindings/clock/marvell,mmp2.h>
+#include <dt-bindings/power/marvell,mmp2.h>
 
 #include "clk.h"
 #include "reset.h"
···
 #define APMU_USBHSIC1	0xfc
 #define APMU_GPU	0xcc
 #define APMU_AUDIO	0x10c
+#define APMU_CAMERA	0x1fc
 
 #define MPMU_FCCR		0x8
 #define MPMU_POSR		0x10
···
 struct mmp2_clk_unit {
 	struct mmp_clk_unit unit;
 	enum mmp2_clk_model model;
+	struct genpd_onecell_data pd_data;
+	struct generic_pm_domain *pm_domains[MMP2_NR_POWER_DOMAINS];
 	void __iomem *mpmu_base;
 	void __iomem *apmu_base;
 	void __iomem *apbc_base;
···
 	mmp_clk_reset_register(np, cells, nr_resets);
 }
 
+static void mmp2_pm_domain_init(struct device_node *np,
+				struct mmp2_clk_unit *pxa_unit)
+{
+	if (pxa_unit->model == CLK_MODEL_MMP3) {
+		pxa_unit->pm_domains[MMP2_POWER_DOMAIN_GPU]
+			= mmp_pm_domain_register("gpu",
+				pxa_unit->apmu_base + APMU_GPU,
+				0x0600, 0x40003, 0x18000c, 0, &gpu_lock);
+	} else {
+		pxa_unit->pm_domains[MMP2_POWER_DOMAIN_GPU]
+			= mmp_pm_domain_register("gpu",
+				pxa_unit->apmu_base + APMU_GPU,
+				0x8600, 0x00003, 0x00000c,
+				MMP_PM_DOMAIN_NO_DISABLE, &gpu_lock);
+	}
+	pxa_unit->pd_data.num_domains++;
+
+	pxa_unit->pm_domains[MMP2_POWER_DOMAIN_AUDIO]
+		= mmp_pm_domain_register("audio",
+			pxa_unit->apmu_base + APMU_AUDIO,
+			0x600, 0x2, 0, 0, &audio_lock);
+	pxa_unit->pd_data.num_domains++;
+
+	if (pxa_unit->model == CLK_MODEL_MMP3) {
+		pxa_unit->pm_domains[MMP3_POWER_DOMAIN_CAMERA]
+			= mmp_pm_domain_register("camera",
+				pxa_unit->apmu_base + APMU_CAMERA,
+				0x600, 0, 0, 0, NULL);
+		pxa_unit->pd_data.num_domains++;
+	}
+
+	pxa_unit->pd_data.domains = pxa_unit->pm_domains;
+	of_genpd_add_provider_onecell(np, &pxa_unit->pd_data);
+}
+
 static void __init mmp2_clk_init(struct device_node *np)
 {
 	struct mmp2_clk_unit *pxa_unit;
···
 		pr_err("failed to map apbc registers\n");
 		goto unmap_apmu_region;
 	}
+
+	mmp2_pm_domain_init(np, pxa_unit);
 
 	mmp_clk_init(np, &pxa_unit->unit, MMP2_NR_CLKS);
 

drivers/clk/mmp/clk.h

···
 #define __MACH_MMP_CLK_H
 
 #include <linux/clk-provider.h>
+#include <linux/pm_domain.h>
 #include <linux/clkdev.h>
 
 #define APBC_NO_BUS_CTRL	BIT(0)
···
 		int nr_clks);
 void mmp_clk_add(struct mmp_clk_unit *unit, unsigned int id,
 		struct clk *clk);
+
+/* Power islands */
+#define MMP_PM_DOMAIN_NO_DISABLE		BIT(0)
+
+struct generic_pm_domain *mmp_pm_domain_register(const char *name,
+		void __iomem *reg,
+		u32 power_on, u32 reset, u32 clock_enable,
+		unsigned int flags, spinlock_t *lock);
+
 #endif

drivers/clk/mmp/pwr-island.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MMP PMU power island support
+ *
+ * Copyright (C) 2020 Lubomir Rintel <[e-mail]>
+ */
+
+#include <linux/pm_domain.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "clk.h"
+
+#define to_mmp_pm_domain(genpd) container_of(genpd, struct mmp_pm_domain, genpd)
+
+struct mmp_pm_domain {
+	struct generic_pm_domain genpd;
+	void __iomem *reg;
+	spinlock_t *lock;
+	u32 power_on;
+	u32 reset;
+	u32 clock_enable;
+	unsigned int flags;
+};
+
+static int mmp_pm_domain_power_on(struct generic_pm_domain *genpd)
+{
+	struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
+	unsigned long flags = 0;
+	u32 val;
+
+	if (pm_domain->lock)
+		spin_lock_irqsave(pm_domain->lock, flags);
+
+	val = readl(pm_domain->reg);
+
+	/* Turn on the power island */
+	val |= pm_domain->power_on;
+	writel(val, pm_domain->reg);
+
+	/* Disable isolation */
+	val |= 0x100;
+	writel(val, pm_domain->reg);
+
+	/* Some blocks need to be reset after a power up */
+	if (pm_domain->reset || pm_domain->clock_enable) {
+		u32 after_power_on = val;
+
+		val &= ~pm_domain->reset;
+		writel(val, pm_domain->reg);
+
+		val |= pm_domain->clock_enable;
+		writel(val, pm_domain->reg);
+
+		val |= pm_domain->reset;
+		writel(val, pm_domain->reg);
+
+		writel(after_power_on, pm_domain->reg);
+	}
+
+	if (pm_domain->lock)
+		spin_unlock_irqrestore(pm_domain->lock, flags);
+
+	return 0;
+}
+
+static int mmp_pm_domain_power_off(struct generic_pm_domain *genpd)
+{
+	struct mmp_pm_domain *pm_domain = to_mmp_pm_domain(genpd);
+	unsigned long flags = 0;
+	u32 val;
+
+	if (pm_domain->flags & MMP_PM_DOMAIN_NO_DISABLE)
+		return 0;
+
+	if (pm_domain->lock)
+		spin_lock_irqsave(pm_domain->lock, flags);
+
+	/* Turn off and isolate the the power island. */
+	val = readl(pm_domain->reg);
+	val &= ~pm_domain->power_on;
+	val &= ~0x100;
+	writel(val, pm_domain->reg);
+
+	if (pm_domain->lock)
+		spin_unlock_irqrestore(pm_domain->lock, flags);
+
+	return 0;
+}
+
+struct generic_pm_domain *mmp_pm_domain_register(const char *name,
+		void __iomem *reg,
+		u32 power_on, u32 reset, u32 clock_enable,
+		unsigned int flags, spinlock_t *lock)
+{
+	struct mmp_pm_domain *pm_domain;
+
+	pm_domain = kzalloc(sizeof(*pm_domain), GFP_KERNEL);
+	if (!pm_domain)
+		return ERR_PTR(-ENOMEM);
+
+	pm_domain->reg = reg;
+	pm_domain->power_on = power_on;
+	pm_domain->reset = reset;
+	pm_domain->clock_enable = clock_enable;
+	pm_domain->flags = flags;
+	pm_domain->lock = lock;
+
+	pm_genpd_init(&pm_domain->genpd, NULL, true);
+	pm_domain->genpd.name = name;
+	pm_domain->genpd.power_on = mmp_pm_domain_power_on;
+	pm_domain->genpd.power_off = mmp_pm_domain_power_off;
+
+	return &pm_domain->genpd;
+}