2 files changed, 457 insertions, 0 deletions
diff --git a/drivers/soc/dove/Makefile b/drivers/soc/dove/Makefile
new file mode 100644
index 000000000..daf4549ec
--- /dev/null
+++ b/drivers/soc/dove/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y		+= pmu.o
diff --git a/drivers/soc/dove/pmu.c b/drivers/soc/dove/pmu.c
new file mode 100644
index 000000000..ffc5311c0
--- /dev/null
+++ b/drivers/soc/dove/pmu.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Marvell Dove PMU support
+ */
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/reset.h>
+#include <linux/reset-controller.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/soc/dove/pmu.h>
+#include <linux/spinlock.h>
+
+#define NR_PMU_IRQS		7
+
+#define PMC_SW_RST		0x30
+#define PMC_IRQ_CAUSE		0x50
+#define PMC_IRQ_MASK		0x54
+
+#define PMU_PWR			0x10
+#define PMU_ISO			0x58
+
+struct pmu_data {
+	spinlock_t lock;
+	struct device_node *of_node;
+	void __iomem *pmc_base;
+	void __iomem *pmu_base;
+	struct irq_chip_generic *irq_gc;
+	struct irq_domain *irq_domain;
+#ifdef CONFIG_RESET_CONTROLLER
+	struct reset_controller_dev reset;
+#endif
+};
+
+/*
+ * The PMU contains a register to reset various subsystems within the
+ * SoC.  Export this as a reset controller.
+ */
+#ifdef CONFIG_RESET_CONTROLLER
+#define rcdev_to_pmu(rcdev) container_of(rcdev, struct pmu_data, reset)
+
+static int pmu_reset_reset(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct pmu_data *pmu = rcdev_to_pmu(rc);
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&pmu->lock, flags);
+	val = readl_relaxed(pmu->pmc_base + PMC_SW_RST);
+	writel_relaxed(val & ~BIT(id), pmu->pmc_base + PMC_SW_RST);
+	writel_relaxed(val | BIT(id), pmu->pmc_base + PMC_SW_RST);
+	spin_unlock_irqrestore(&pmu->lock, flags);
+
+	return 0;
+}
+
+static int pmu_reset_assert(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct pmu_data *pmu = rcdev_to_pmu(rc);
+	unsigned long flags;
+	u32 val = ~BIT(id);
+
+	spin_lock_irqsave(&pmu->lock, flags);
+	val &= readl_relaxed(pmu->pmc_base + PMC_SW_RST);
+	writel_relaxed(val, pmu->pmc_base + PMC_SW_RST);
+	spin_unlock_irqrestore(&pmu->lock, flags);
+
+	return 0;
+}
+
+static int pmu_reset_deassert(struct reset_controller_dev *rc, unsigned long id)
+{
+	struct pmu_data *pmu = rcdev_to_pmu(rc);
+	unsigned long flags;
+	u32 val = BIT(id);
+
+	spin_lock_irqsave(&pmu->lock, flags);
+	val |= readl_relaxed(pmu->pmc_base + PMC_SW_RST);
+	writel_relaxed(val, pmu->pmc_base + PMC_SW_RST);
+	spin_unlock_irqrestore(&pmu->lock, flags);
+
+	return 0;
+}
+
+static const struct reset_control_ops pmu_reset_ops = {
+	.reset = pmu_reset_reset,
+	.assert = pmu_reset_assert,
+	.deassert = pmu_reset_deassert,
+};
+
+static struct reset_controller_dev pmu_reset __initdata = {
+	.ops = &pmu_reset_ops,
+	.owner = THIS_MODULE,
+	.nr_resets = 32,
+};
+
+static void __init pmu_reset_init(struct pmu_data *pmu)
+{
+	int ret;
+
+	pmu->reset = pmu_reset;
+	pmu->reset.of_node = pmu->of_node;
+
+	ret = reset_controller_register(&pmu->reset);
+	if (ret)
+		pr_err("pmu: %s failed: %d\n", "reset_controller_register", ret);
+}
+#else
+static void __init pmu_reset_init(struct pmu_data *pmu)
+{
+}
+#endif
+
+struct pmu_domain {
+	struct pmu_data *pmu;
+	u32 pwr_mask;
+	u32 rst_mask;
+	u32 iso_mask;
+	struct generic_pm_domain base;
+};
+
+#define to_pmu_domain(dom) container_of(dom, struct pmu_domain, base)
+
+/*
+ * This deals with the "old" Marvell sequence of bringing a power domain
+ * down/up, which is: apply power, release reset, disable isolators.
+ *
+ * Later devices apparantly use a different sequence: power up, disable
+ * isolators, assert repair signal, enable SRMA clock, enable AXI clock,
+ * enable module clock, deassert reset.
+ *
+ * Note: reading the assembly, it seems that the IO accessors have an
+ * unfortunate side-effect - they cause memory already read into registers
+ * for the if () to be re-read for the bit-set or bit-clear operation.
+ * The code is written to avoid this.
+ */
+static int pmu_domain_power_off(struct generic_pm_domain *domain)
+{
+	struct pmu_domain *pmu_dom = to_pmu_domain(domain);
+	struct pmu_data *pmu = pmu_dom->pmu;
+	unsigned long flags;
+	unsigned int val;
+	void __iomem *pmu_base = pmu->pmu_base;
+	void __iomem *pmc_base = pmu->pmc_base;
+
+	spin_lock_irqsave(&pmu->lock, flags);
+
+	/* Enable isolators */
+	if (pmu_dom->iso_mask) {
+		val = ~pmu_dom->iso_mask;
+		val &= readl_relaxed(pmu_base + PMU_ISO);
+		writel_relaxed(val, pmu_base + PMU_ISO);
+	}
+
+	/* Reset unit */
+	if (pmu_dom->rst_mask) {
+		val = ~pmu_dom->rst_mask;
+		val &= readl_relaxed(pmc_base + PMC_SW_RST);
+		writel_relaxed(val, pmc_base + PMC_SW_RST);
+	}
+
+	/* Power down */
+	val = readl_relaxed(pmu_base + PMU_PWR) | pmu_dom->pwr_mask;
+	writel_relaxed(val, pmu_base + PMU_PWR);
+
+	spin_unlock_irqrestore(&pmu->lock, flags);
+
+	return 0;
+}
+
+static int pmu_domain_power_on(struct generic_pm_domain *domain)
+{
+	struct pmu_domain *pmu_dom = to_pmu_domain(domain);
+	struct pmu_data *pmu = pmu_dom->pmu;
+	unsigned long flags;
+	unsigned int val;
+	void __iomem *pmu_base = pmu->pmu_base;
+	void __iomem *pmc_base = pmu->pmc_base;
+
+	spin_lock_irqsave(&pmu->lock, flags);
+
+	/* Power on */
+	val = ~pmu_dom->pwr_mask & readl_relaxed(pmu_base + PMU_PWR);
+	writel_relaxed(val, pmu_base + PMU_PWR);
+
+	/* Release reset */
+	if (pmu_dom->rst_mask) {
+		val = pmu_dom->rst_mask;
+		val |= readl_relaxed(pmc_base + PMC_SW_RST);
+		writel_relaxed(val, pmc_base + PMC_SW_RST);
+	}
+
+	/* Disable isolators */
+	if (pmu_dom->iso_mask) {
+		val = pmu_dom->iso_mask;
+		val |= readl_relaxed(pmu_base + PMU_ISO);
+		writel_relaxed(val, pmu_base + PMU_ISO);
+	}
+
+	spin_unlock_irqrestore(&pmu->lock, flags);
+
+	return 0;
+}
+
+static void __pmu_domain_register(struct pmu_domain *domain,
+	struct device_node *np)
+{
+	unsigned int val = readl_relaxed(domain->pmu->pmu_base + PMU_PWR);
+
+	domain->base.power_off = pmu_domain_power_off;
+	domain->base.power_on = pmu_domain_power_on;
+
+	pm_genpd_init(&domain->base, NULL, !(val & domain->pwr_mask));
+
+	if (np)
+		of_genpd_add_provider_simple(np, &domain->base);
+}
+
+/* PMU IRQ controller */
+static void pmu_irq_handler(struct irq_desc *desc)
+{
+	struct pmu_data *pmu = irq_desc_get_handler_data(desc);
+	struct irq_chip_generic *gc = pmu->irq_gc;
+	struct irq_domain *domain = pmu->irq_domain;
+	void __iomem *base = gc->reg_base;
+	u32 stat = readl_relaxed(base + PMC_IRQ_CAUSE) & gc->mask_cache;
+	u32 done = ~0;
+
+	if (stat == 0) {
+		handle_bad_irq(desc);
+		return;
+	}
+
+	while (stat) {
+		u32 hwirq = fls(stat) - 1;
+
+		stat &= ~(1 << hwirq);
+		done &= ~(1 << hwirq);
+
+		generic_handle_irq(irq_find_mapping(domain, hwirq));
+	}
+
+	/*
+	 * The PMU mask register is not RW0C: it is RW.  This means that
+	 * the bits take whatever value is written to them; if you write
+	 * a '1', you will set the interrupt.
+	 *
+	 * Unfortunately this means there is NO race free way to clear
+	 * these interrupts.
+	 *
+	 * So, let's structure the code so that the window is as small as
+	 * possible.
+	 */
+	irq_gc_lock(gc);
+	done &= readl_relaxed(base + PMC_IRQ_CAUSE);
+	writel_relaxed(done, base + PMC_IRQ_CAUSE);
+	irq_gc_unlock(gc);
+}
+
+static int __init dove_init_pmu_irq(struct pmu_data *pmu, int irq)
+{
+	const char *name = "pmu_irq";
+	struct irq_chip_generic *gc;
+	struct irq_domain *domain;
+	int ret;
+
+	/* mask and clear all interrupts */
+	writel(0, pmu->pmc_base + PMC_IRQ_MASK);
+	writel(0, pmu->pmc_base + PMC_IRQ_CAUSE);
+
+	domain = irq_domain_add_linear(pmu->of_node, NR_PMU_IRQS,
+				       &irq_generic_chip_ops, NULL);
+	if (!domain) {
+		pr_err("%s: unable to add irq domain\n", name);
+		return -ENOMEM;
+	}
+
+	ret = irq_alloc_domain_generic_chips(domain, NR_PMU_IRQS, 1, name,
+					     handle_level_irq,
+					     IRQ_NOREQUEST | IRQ_NOPROBE, 0,
+					     IRQ_GC_INIT_MASK_CACHE);
+	if (ret) {
+		pr_err("%s: unable to alloc irq domain gc: %d\n", name, ret);
+		irq_domain_remove(domain);
+		return ret;
+	}
+
+	gc = irq_get_domain_generic_chip(domain, 0);
+	gc->reg_base = pmu->pmc_base;
+	gc->chip_types[0].regs.mask = PMC_IRQ_MASK;
+	gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
+	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
+
+	pmu->irq_domain = domain;
+	pmu->irq_gc = gc;
+
+	irq_set_handler_data(irq, pmu);
+	irq_set_chained_handler(irq, pmu_irq_handler);
+
+	return 0;
+}
+
+int __init dove_init_pmu_legacy(const struct dove_pmu_initdata *initdata)
+{
+	const struct dove_pmu_domain_initdata *domain_initdata;
+	struct pmu_data *pmu;
+	int ret;
+
+	pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
+	if (!pmu)
+		return -ENOMEM;
+
+	spin_lock_init(&pmu->lock);
+	pmu->pmc_base = initdata->pmc_base;
+	pmu->pmu_base = initdata->pmu_base;
+
+	pmu_reset_init(pmu);
+	for (domain_initdata = initdata->domains; domain_initdata->name;
+	     domain_initdata++) {
+		struct pmu_domain *domain;
+
+		domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+		if (domain) {
+			domain->pmu = pmu;
+			domain->pwr_mask = domain_initdata->pwr_mask;
+			domain->rst_mask = domain_initdata->rst_mask;
+			domain->iso_mask = domain_initdata->iso_mask;
+			domain->base.name = domain_initdata->name;
+
+			__pmu_domain_register(domain, NULL);
+		}
+	}
+
+	ret = dove_init_pmu_irq(pmu, initdata->irq);
+	if (ret)
+		pr_err("dove_init_pmu_irq() failed: %d\n", ret);
+
+	if (pmu->irq_domain)
+		irq_domain_associate_many(pmu->irq_domain,
+					  initdata->irq_domain_start,
+					  0, NR_PMU_IRQS);
+
+	return 0;
+}
+
+/*
+ * pmu: power-manager@d0000 {
+ *	compatible = "marvell,dove-pmu";
+ *	reg = <0xd0000 0x8000> <0xd8000 0x8000>;
+ *	interrupts = <33>;
+ *	interrupt-controller;
+ *	#reset-cells = 1;
+ *	vpu_domain: vpu-domain {
+ *		#power-domain-cells = <0>;
+ *		marvell,pmu_pwr_mask = <0x00000008>;
+ *		marvell,pmu_iso_mask = <0x00000001>;
+ *		resets = <&pmu 16>;
+ *	};
+ *	gpu_domain: gpu-domain {
+ *		#power-domain-cells = <0>;
+ *		marvell,pmu_pwr_mask = <0x00000004>;
+ *		marvell,pmu_iso_mask = <0x00000002>;
+ *		resets = <&pmu 18>;
+ *	};
+ * };
+ */
+int __init dove_init_pmu(void)
+{
+	struct device_node *np_pmu, *domains_node, *np;
+	struct pmu_data *pmu;
+	int ret, parent_irq;
+
+	/* Lookup the PMU node */
+	np_pmu = of_find_compatible_node(NULL, NULL, "marvell,dove-pmu");
+	if (!np_pmu)
+		return 0;
+
+	domains_node = of_get_child_by_name(np_pmu, "domains");
+	if (!domains_node) {
+		pr_err("%pOFn: failed to find domains sub-node\n", np_pmu);
+		return 0;
+	}
+
+	pmu = kzalloc(sizeof(*pmu), GFP_KERNEL);
+	if (!pmu)
+		return -ENOMEM;
+
+	spin_lock_init(&pmu->lock);
+	pmu->of_node = np_pmu;
+	pmu->pmc_base = of_iomap(pmu->of_node, 0);
+	pmu->pmu_base = of_iomap(pmu->of_node, 1);
+	if (!pmu->pmc_base || !pmu->pmu_base) {
+		pr_err("%pOFn: failed to map PMU\n", np_pmu);
+		iounmap(pmu->pmu_base);
+		iounmap(pmu->pmc_base);
+		kfree(pmu);
+		return -ENOMEM;
+	}
+
+	pmu_reset_init(pmu);
+
+	for_each_available_child_of_node(domains_node, np) {
+		struct of_phandle_args args;
+		struct pmu_domain *domain;
+
+		domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+		if (!domain)
+			break;
+
+		domain->pmu = pmu;
+		domain->base.name = kasprintf(GFP_KERNEL, "%pOFn", np);
+		if (!domain->base.name) {
+			kfree(domain);
+			break;
+		}
+
+		of_property_read_u32(np, "marvell,pmu_pwr_mask",
+				     &domain->pwr_mask);
+		of_property_read_u32(np, "marvell,pmu_iso_mask",
+				     &domain->iso_mask);
+
+		/*
+		 * We parse the reset controller property directly here
+		 * to ensure that we can operate when the reset controller
+		 * support is not configured into the kernel.
+		 */
+		ret = of_parse_phandle_with_args(np, "resets", "#reset-cells",
+						 0, &args);
+		if (ret == 0) {
+			if (args.np == pmu->of_node)
+				domain->rst_mask = BIT(args.args[0]);
+			of_node_put(args.np);
+		}
+
+		__pmu_domain_register(domain, np);
+	}
+
+	/* Loss of the interrupt controller is not a fatal error. */
+	parent_irq = irq_of_parse_and_map(pmu->of_node, 0);
+	if (!parent_irq) {
+		pr_err("%pOFn: no interrupt specified\n", np_pmu);
+	} else {
+		ret = dove_init_pmu_irq(pmu, parent_irq);
+		if (ret)
+			pr_err("dove_init_pmu_irq() failed: %d\n", ret);
+	}
+
+	return 0;
+}