Thread (11 messages) 11 messages, 4 authors, 2015-02-16
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[PATCH 4/8] ARM: dove: create a proper PMU driver for power domains, PMU IRQs and resets

From: sebastian.hesselbarth@gmail.com (Sebastian Hesselbarth)
Date: 2015-02-14 17:02:11

On 14.02.2015 16:27, Russell King wrote:
The PMU device contains an interrupt controller, power control and
resets.  The interrupt controller is a little sub-standard in that
there is no race free way to clear down pending interrupts, so we try
to avoid problems by reducing the window as much as possible, and
clearing as infrequently as possible.

The interrupt support is implemented using an IRQ domain, and the
parent interrupt referenced in the standard DT way.

The power domains and reset support is closely related - there is a
defined sequence for powering down a domain which is tightly coupled
with asserting the reset.  Hence, it makes sense to group these two
together.

This patch adds the core PMU driver: power domains must be defined in
the DT file in order to make use of them.  The reset controller can
be referenced in the standard way for reset controllers.

Signed-off-by: Russell King <redacted>
---
[...]
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/mach-dove/pmu.c b/arch/arm/mach-dove/pmu.c
new file mode 100644
index 000000000000..2d1325995a68
--- /dev/null
+++ b/arch/arm/mach-dove/pmu.c
@@ -0,0 +1,410 @@
+/*
+ * Marvell Dove PMU support
+ */
[...]
+/*
+ * pmu {
+ *	compatible = "marvell,pmu";
Russell,

Should we be more precise and call it "marvell,dove-pmu" ?

Also, can we have an additional "syscon" compatible for that node?

That will allow us to get rid of the messy iomem stuff current
pinctrl-dove is doing to get access to the pmu pinctrl registers.
+ *	reg = <0xd0000 0x8000> <0xd8000 0x8000>;
+ *	interrupts = <33>;
+ *	#reset-cells = 1;
+ *	#power-domain-cells = <0>;
+ *	vpu_domain: vpu-domain {
+ *		marvell,pmu_pwr_mask = <0x00000008>;
+ *		marvell,pmu_iso_mask = <0x00000001>;
+ *		resets = <&pmu 16>;
+ *	};
+ *	gpu_domain: gpu-domain {
+ *		marvell,pmu_pwr_mask = <0x00000004>;
+ *		marvell,pmu_iso_mask = <0x00000002>;
+ *		resets = <&pmu 18>;
+ *	};
+ * };
+ */
+int __init dove_init_pmu(void)
+{
How about we copy the clk subsystem way of installing early probed
pm for DT here?

For example:

#define PM_OF_DECLARE(name, compat, fn) OF_DECLARE_1(clk, name, compat, fn)

and

static int __init dove_pmu_init(struct device_node *np) { ... }
PM_OF_DECLARE(dove_pmu, "marvell,dove-pmu", dove_init_pmu);

Sebastian
+	struct device_node *np_pmu, *np;
+	struct pmu_data *pmu;
+	int ret, parent_irq;
+
+	/* Lookup the PMU node */
+	np_pmu = of_find_compatible_node(NULL, NULL, "marvell,pmu");
+	if (!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("%s: failed to map PMU\n", np_pmu->name);
+		iounmap(pmu->pmu_base);
+		iounmap(pmu->pmc_base);
+		kfree(pmu);
+		return -ENOMEM;
+	}
+
+	parent_irq = irq_of_parse_and_map(pmu->of_node, 0);
+	if (!parent_irq)
+		pr_err("%s: no interrupt specified\n", np_pmu->name);
+
+	pmu_reset_init(pmu);
+
+	for_each_available_child_of_node(pmu->of_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 = kstrdup(np->name, GFP_KERNEL);
+		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);
+
+		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);
+	}
+	pm_genpd_poweroff_unused();
+
+	ret = dove_init_pmu_irq(pmu, parent_irq);
+	if (ret)
+		pr_err("dove_init_pmu_irq() failed: %d\n", ret);
+
+	return 0;
+}
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