Actions Semi ARM SoC for v4.13 #2

This adds SMP code to bring up the remaining S500 CPU cores
 by reusing a helper factored out of the SPS power domains driver.
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Merge tag 'actions-arm-soc+sps-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/afaerber/linux-actions into next/soc

Pull "Actions Semi ARM SoC for v4.13 #2" from Andreas Färber:

This adds SMP code to bring up the remaining S500 CPU cores
by reusing a helper factored out of the SPS power domains driver.

* tag 'actions-arm-soc+sps-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/afaerber/linux-actions:
  ARM: owl: smp: Implement SPS power-gating for CPU2 and CPU3
  soc: actions: owl-sps: Factor out owl_sps_set_pg() for power-gating
  soc: actions: Add Owl SPS
  dt-bindings: power: Add Owl SPS power domains

Documentation/devicetree/bindings/power/actions,owl-sps.txt

@@ -0,0 +1,17 @@
+Actions Semi Owl Smart Power System (SPS)
+
+Required properties:
+- compatible          :  "actions,s500-sps" for S500
+- reg                 :  Offset and length of the register set for the device.
+- #power-domain-cells :  Must be 1.
+                         See macros in:
+                          include/dt-bindings/power/owl-s500-powergate.h for S500
+
+
+Example:
+
+		sps: power-controller@b01b0100 {
+			compatible = "actions,s500-sps";
+			reg = <0xb01b0100 0x100>;
+			#power-domain-cells = <1>;
+		};

arch/arm/mach-actions/Kconfig

@@ -10,6 +10,7 @@ menuconfig ARCH_ACTIONS
 	select GENERIC_IRQ_CHIP
 	select HAVE_ARM_SCU if SMP
 	select HAVE_ARM_TWD if SMP
+	select OWL_PM_DOMAINS_HELPER
 	select OWL_TIMER
 	help
 	  This enables support for the Actions Semiconductor S500 SoC family.

arch/arm/mach-actions/platsmp.c

@@ -19,6 +19,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/smp.h>
+#include <linux/soc/actions/owl-sps.h>
 #include <asm/cacheflush.h>
 #include <asm/smp_plat.h>
 #include <asm/smp_scu.h>
@@ -28,7 +29,13 @@
 
 #define OWL_CPUx_FLAG_BOOT	0x55aa
 
+#define OWL_SPS_PG_CTL_PWR_CPU2	BIT(5)
+#define OWL_SPS_PG_CTL_PWR_CPU3	BIT(6)
+#define OWL_SPS_PG_CTL_ACK_CPU2	BIT(21)
+#define OWL_SPS_PG_CTL_ACK_CPU3	BIT(22)
+
 static void __iomem *scu_base_addr;
+static void __iomem *sps_base_addr;
 static void __iomem *timer_base_addr;
 static int ncores;
 
@@ -58,14 +65,27 @@ void owl_secondary_startup(void);
 
 static int s500_wakeup_secondary(unsigned int cpu)
 {
+	int ret;
+
 	if (cpu > 3)
 		return -EINVAL;
 
+	/* The generic PM domain driver is not available this early. */
 	switch (cpu) {
 	case 2:
+		ret = owl_sps_set_pg(sps_base_addr,
+		                     OWL_SPS_PG_CTL_PWR_CPU2,
+				     OWL_SPS_PG_CTL_ACK_CPU2, true);
+		if (ret)
+			return ret;
+		break;
 	case 3:
-		/* CPU2/3 are power-gated */
-		return -EINVAL;
+		ret = owl_sps_set_pg(sps_base_addr,
+		                     OWL_SPS_PG_CTL_PWR_CPU3,
+				     OWL_SPS_PG_CTL_ACK_CPU3, true);
+		if (ret)
+			return ret;
+		break;
 	}
 
 	/* wait for CPUx to run to WFE instruction */
@@ -133,6 +153,18 @@ static void __init s500_smp_prepare_cpus(unsigned int max_cpus)
 		return;
 	}
 
+	node = of_find_compatible_node(NULL, NULL, "actions,s500-sps");
+	if (!node) {
+		pr_err("%s: missing sps\n", __func__);
+		return;
+	}
+
+	sps_base_addr = of_iomap(node, 0);
+	if (!sps_base_addr) {
+		pr_err("%s: could not map sps registers\n", __func__);
+		return;
+	}
+
 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
 		node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
 		if (!node) {

drivers/soc/Kconfig

@@ -1,5 +1,6 @@
 menu "SOC (System On Chip) specific Drivers"
 
+source "drivers/soc/actions/Kconfig"
 source "drivers/soc/atmel/Kconfig"
 source "drivers/soc/bcm/Kconfig"
 source "drivers/soc/fsl/Kconfig"

drivers/soc/Makefile

@@ -2,6 +2,7 @@
 # Makefile for the Linux Kernel SOC specific device drivers.
 #
 
+obj-$(CONFIG_ARCH_ACTIONS)	+= actions/
 obj-$(CONFIG_ARCH_AT91)		+= atmel/
 obj-y				+= bcm/
 obj-$(CONFIG_ARCH_DOVE)		+= dove/

drivers/soc/actions/Kconfig

@@ -0,0 +1,16 @@
+if ARCH_ACTIONS || COMPILE_TEST
+
+config OWL_PM_DOMAINS_HELPER
+	bool
+
+config OWL_PM_DOMAINS
+	bool "Actions Semi SPS power domains"
+	depends on PM
+	select OWL_PM_DOMAINS_HELPER
+	select PM_GENERIC_DOMAINS
+	help
+	  Say 'y' here to enable support for Smart Power System (SPS)
+	  power-gating on Actions Semiconductor S500 SoC.
+	  If unsure, say 'n'.
+
+endif

drivers/soc/actions/Makefile

@@ -0,0 +1,2 @@
+obj-$(CONFIG_OWL_PM_DOMAINS_HELPER) += owl-sps-helper.o
+obj-$(CONFIG_OWL_PM_DOMAINS) += owl-sps.o

drivers/soc/actions/owl-sps-helper.c

@@ -0,0 +1,51 @@
+/*
+ * Actions Semi Owl Smart Power System (SPS) shared helpers
+ *
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#define OWL_SPS_PG_CTL	0x0
+
+int owl_sps_set_pg(void __iomem *base, u32 pwr_mask, u32 ack_mask, bool enable)
+{
+	u32 val;
+	bool ack;
+	int timeout;
+
+	val = readl(base + OWL_SPS_PG_CTL);
+	ack = val & ack_mask;
+	if (ack == enable)
+		return 0;
+
+	if (enable)
+		val |= pwr_mask;
+	else
+		val &= ~pwr_mask;
+
+	writel(val, base + OWL_SPS_PG_CTL);
+
+	for (timeout = 5000; timeout > 0; timeout -= 50) {
+		val = readl(base + OWL_SPS_PG_CTL);
+		if ((val & ack_mask) == (enable ? ack_mask : 0))
+			break;
+		udelay(50);
+	}
+	if (timeout <= 0)
+		return -ETIMEDOUT;
+
+	udelay(10);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(owl_sps_set_pg);

drivers/soc/actions/owl-sps.c

@@ -0,0 +1,224 @@
+/*
+ * Actions Semi Owl Smart Power System (SPS)
+ *
+ * Copyright 2012 Actions Semi Inc.
+ * Author: Actions Semi, Inc.
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/pm_domain.h>
+#include <linux/soc/actions/owl-sps.h>
+#include <dt-bindings/power/owl-s500-powergate.h>
+
+struct owl_sps_domain_info {
+	const char *name;
+	int pwr_bit;
+	int ack_bit;
+	unsigned int genpd_flags;
+};
+
+struct owl_sps_info {
+	unsigned num_domains;
+	const struct owl_sps_domain_info *domains;
+};
+
+struct owl_sps {
+	struct device *dev;
+	const struct owl_sps_info *info;
+	void __iomem *base;
+	struct genpd_onecell_data genpd_data;
+	struct generic_pm_domain *domains[];
+};
+
+#define to_owl_pd(gpd) container_of(gpd, struct owl_sps_domain, genpd)
+
+struct owl_sps_domain {
+	struct generic_pm_domain genpd;
+	const struct owl_sps_domain_info *info;
+	struct owl_sps *sps;
+};
+
+static int owl_sps_set_power(struct owl_sps_domain *pd, bool enable)
+{
+	u32 pwr_mask, ack_mask;
+
+	ack_mask = BIT(pd->info->ack_bit);
+	pwr_mask = BIT(pd->info->pwr_bit);
+
+	return owl_sps_set_pg(pd->sps->base, pwr_mask, ack_mask, enable);
+}
+
+static int owl_sps_power_on(struct generic_pm_domain *domain)
+{
+	struct owl_sps_domain *pd = to_owl_pd(domain);
+
+	dev_dbg(pd->sps->dev, "%s power on", pd->info->name);
+
+	return owl_sps_set_power(pd, true);
+}
+
+static int owl_sps_power_off(struct generic_pm_domain *domain)
+{
+	struct owl_sps_domain *pd = to_owl_pd(domain);
+
+	dev_dbg(pd->sps->dev, "%s power off", pd->info->name);
+
+	return owl_sps_set_power(pd, false);
+}
+
+static int owl_sps_init_domain(struct owl_sps *sps, int index)
+{
+	struct owl_sps_domain *pd;
+
+	pd = devm_kzalloc(sps->dev, sizeof(*pd), GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+
+	pd->info = &sps->info->domains[index];
+	pd->sps = sps;
+
+	pd->genpd.name = pd->info->name;
+	pd->genpd.power_on = owl_sps_power_on;
+	pd->genpd.power_off = owl_sps_power_off;
+	pd->genpd.flags = pd->info->genpd_flags;
+	pm_genpd_init(&pd->genpd, NULL, false);
+
+	sps->genpd_data.domains[index] = &pd->genpd;
+
+	return 0;
+}
+
+static int owl_sps_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	const struct owl_sps_info *sps_info;
+	struct owl_sps *sps;
+	int i, ret;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "no device node\n");
+		return -ENODEV;
+	}
+
+	match = of_match_device(pdev->dev.driver->of_match_table, &pdev->dev);
+	if (!match || !match->data) {
+		dev_err(&pdev->dev, "unknown compatible or missing data\n");
+		return -EINVAL;
+	}
+
+	sps_info = match->data;
+
+	sps = devm_kzalloc(&pdev->dev, sizeof(*sps) +
+			   sps_info->num_domains * sizeof(sps->domains[0]),
+			   GFP_KERNEL);
+	if (!sps)
+		return -ENOMEM;
+
+	sps->base = of_io_request_and_map(pdev->dev.of_node, 0, "owl-sps");
+	if (IS_ERR(sps->base)) {
+		dev_err(&pdev->dev, "failed to map sps registers\n");
+		return PTR_ERR(sps->base);
+	}
+
+	sps->dev = &pdev->dev;
+	sps->info = sps_info;
+	sps->genpd_data.domains = sps->domains;
+	sps->genpd_data.num_domains = sps_info->num_domains;
+
+	for (i = 0; i < sps_info->num_domains; i++) {
+		ret = owl_sps_init_domain(sps, i);
+		if (ret)
+			return ret;
+	}
+
+	ret = of_genpd_add_provider_onecell(pdev->dev.of_node, &sps->genpd_data);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to add provider (%d)", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct owl_sps_domain_info s500_sps_domains[] = {
+	[S500_PD_VDE] = {
+		.name = "VDE",
+		.pwr_bit = 0,
+		.ack_bit = 16,
+	},
+	[S500_PD_VCE_SI] = {
+		.name = "VCE_SI",
+		.pwr_bit = 1,
+		.ack_bit = 17,
+	},
+	[S500_PD_USB2_1] = {
+		.name = "USB2_1",
+		.pwr_bit = 2,
+		.ack_bit = 18,
+	},
+	[S500_PD_CPU2] = {
+		.name = "CPU2",
+		.pwr_bit = 5,
+		.ack_bit = 21,
+		.genpd_flags = GENPD_FLAG_ALWAYS_ON,
+	},
+	[S500_PD_CPU3] = {
+		.name = "CPU3",
+		.pwr_bit = 6,
+		.ack_bit = 22,
+		.genpd_flags = GENPD_FLAG_ALWAYS_ON,
+	},
+	[S500_PD_DMA] = {
+		.name = "DMA",
+		.pwr_bit = 8,
+		.ack_bit = 12,
+	},
+	[S500_PD_DS] = {
+		.name = "DS",
+		.pwr_bit = 9,
+		.ack_bit = 13,
+	},
+	[S500_PD_USB3] = {
+		.name = "USB3",
+		.pwr_bit = 10,
+		.ack_bit = 14,
+	},
+	[S500_PD_USB2_0] = {
+		.name = "USB2_0",
+		.pwr_bit = 11,
+		.ack_bit = 15,
+	},
+};
+
+static const struct owl_sps_info s500_sps_info = {
+	.num_domains = ARRAY_SIZE(s500_sps_domains),
+	.domains = s500_sps_domains,
+};
+
+static const struct of_device_id owl_sps_of_matches[] = {
+	{ .compatible = "actions,s500-sps", .data = &s500_sps_info },
+	{ }
+};
+
+static struct platform_driver owl_sps_platform_driver = {
+	.probe = owl_sps_probe,
+	.driver = {
+		.name = "owl-sps",
+		.of_match_table = owl_sps_of_matches,
+		.suppress_bind_attrs = true,
+	},
+};
+
+static int __init owl_sps_init(void)
+{
+	return platform_driver_register(&owl_sps_platform_driver);
+}
+postcore_initcall(owl_sps_init);

include/dt-bindings/power/owl-s500-powergate.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+ */
+#ifndef DT_BINDINGS_POWER_OWL_S500_POWERGATE_H
+#define DT_BINDINGS_POWER_OWL_S500_POWERGATE_H
+
+#define S500_PD_VDE	0
+#define S500_PD_VCE_SI	1
+#define S500_PD_USB2_1	2
+#define S500_PD_CPU2	3
+#define S500_PD_CPU3	4
+#define S500_PD_DMA	5
+#define S500_PD_DS	6
+#define S500_PD_USB3	7
+#define S500_PD_USB2_0	8
+
+#endif

include/linux/soc/actions/owl-sps.h

@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+#ifndef SOC_ACTIONS_OWL_SPS_H
+#define SOC_ACTIONS_OWL_SPS_H
+
+int owl_sps_set_pg(void __iomem *base, u32 pwr_mask, u32 ack_mask, bool enable);
+
+#endif