soc: bcm: add BCM63xx power domain driver

BCM6318, BCM6328, BCM6362 and BCM63268 SoCs have a power domain controller
to enable/disable certain components in order to save power.

Signed-off-by: Álvaro Fernández Rojas <[e-mail]>
Reviewed-by: Florian Fainelli <[e-mail]>
Signed-off-by: Florian Fainelli <[e-mail]>

MAINTAINERS

···
 F:	arch/mips/boot/dts/brcm/bcm*.dts*
 F:	arch/mips/include/asm/mach-bmips/*
 F:	arch/mips/kernel/*bmips*
+F:	drivers/soc/bcm/bcm63xx
 F:	drivers/irqchip/irq-bcm63*
 F:	drivers/irqchip/irq-bcm7*
 F:	drivers/irqchip/irq-brcmstb*

drivers/soc/bcm/Kconfig

···
 	  This enables support for the RPi power domains which can be enabled
 	  or disabled via the RPi firmware.
 
+config SOC_BCM63XX
+	bool "Broadcom 63xx SoC drivers"
+	depends on BMIPS_GENERIC || COMPILE_TEST
+	help
+	  Enables drivers for the Broadcom 63xx series of chips.
+	  Drivers can be enabled individually within this menu.
+
+	  If unsure, say N.
+
 config SOC_BRCMSTB
 	bool "Broadcom STB SoC drivers"
 	depends on ARM || ARM64 || BMIPS_GENERIC || COMPILE_TEST
···
 
 	  If unsure, say N.
 
+source "drivers/soc/bcm/bcm63xx/Kconfig"
 source "drivers/soc/bcm/brcmstb/Kconfig"
 
 endmenu

drivers/soc/bcm/Makefile

···
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_BCM2835_POWER)	+= bcm2835-power.o
 obj-$(CONFIG_RASPBERRYPI_POWER)	+= raspberrypi-power.o
+obj-$(CONFIG_SOC_BCM63XX)	+= bcm63xx/
 obj-$(CONFIG_SOC_BRCMSTB)	+= brcmstb/

drivers/soc/bcm/bcm63xx/Kconfig

···
+# SPDX-License-Identifier: GPL-2.0-only
+if SOC_BCM63XX
+
+config BCM63XX_POWER
+	bool "BCM63xx power domain driver"
+	depends on BMIPS_GENERIC || (COMPILE_TEST && OF)
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the BCM63xx power domains controller on
+	  BCM6318, BCM6328, BCM6362 and BCM63268 SoCs.
+
+endif # SOC_BCM63XX

drivers/soc/bcm/bcm63xx/Makefile

···
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_BCM63XX_POWER) += bcm63xx-power.o

drivers/soc/bcm/bcm63xx/bcm63xx-power.c

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * BCM63xx Power Domain Controller Driver
+ *
+ * Copyright (C) 2020 Álvaro Fernández Rojas <[e-mail]>
+ */
+
+#include <dt-bindings/soc/bcm6318-pm.h>
+#include <dt-bindings/soc/bcm6328-pm.h>
+#include <dt-bindings/soc/bcm6362-pm.h>
+#include <dt-bindings/soc/bcm63268-pm.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+struct bcm63xx_power_dev {
+	struct generic_pm_domain genpd;
+	struct bcm63xx_power *power;
+	uint32_t mask;
+};
+
+struct bcm63xx_power {
+	void __iomem *base;
+	spinlock_t lock;
+	struct bcm63xx_power_dev *dev;
+	struct genpd_onecell_data genpd_data;
+	struct generic_pm_domain **genpd;
+};
+
+struct bcm63xx_power_data {
+	const char * const name;
+	uint8_t bit;
+	unsigned int flags;
+};
+
+static int bcm63xx_power_get_state(struct bcm63xx_power_dev *pmd, bool *is_on)
+{
+	struct bcm63xx_power *power = pmd->power;
+
+	if (!pmd->mask) {
+		*is_on = false;
+		return -EINVAL;
+	}
+
+	*is_on = !(__raw_readl(power->base) & pmd->mask);
+
+	return 0;
+}
+
+static int bcm63xx_power_set_state(struct bcm63xx_power_dev *pmd, bool on)
+{
+	struct bcm63xx_power *power = pmd->power;
+	unsigned long flags;
+	uint32_t val;
+
+	if (!pmd->mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&power->lock, flags);
+	val = __raw_readl(power->base);
+	if (on)
+		val &= ~pmd->mask;
+	else
+		val |= pmd->mask;
+	__raw_writel(val, power->base);
+	spin_unlock_irqrestore(&power->lock, flags);
+
+	return 0;
+}
+
+static int bcm63xx_power_on(struct generic_pm_domain *genpd)
+{
+	struct bcm63xx_power_dev *pmd = container_of(genpd,
+		struct bcm63xx_power_dev, genpd);
+
+	return bcm63xx_power_set_state(pmd, true);
+}
+
+static int bcm63xx_power_off(struct generic_pm_domain *genpd)
+{
+	struct bcm63xx_power_dev *pmd = container_of(genpd,
+		struct bcm63xx_power_dev, genpd);
+
+	return bcm63xx_power_set_state(pmd, false);
+}
+
+static int bcm63xx_power_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct resource *res;
+	const struct bcm63xx_power_data *entry, *table;
+	struct bcm63xx_power *power;
+	unsigned int ndom;
+	uint8_t max_bit = 0;
+	int ret;
+
+	power = devm_kzalloc(dev, sizeof(*power), GFP_KERNEL);
+	if (!power)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	power->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(power->base))
+		return PTR_ERR(power->base);
+
+	table = of_device_get_match_data(dev);
+	if (!table)
+		return -EINVAL;
+
+	power->genpd_data.num_domains = 0;
+	ndom = 0;
+	for (entry = table; entry->name; entry++) {
+		max_bit = max(max_bit, entry->bit);
+		ndom++;
+	}
+
+	if (!ndom)
+		return -ENODEV;
+
+	power->genpd_data.num_domains = max_bit + 1;
+
+	power->dev = devm_kcalloc(dev, power->genpd_data.num_domains,
+				  sizeof(struct bcm63xx_power_dev),
+				  GFP_KERNEL);
+	if (!power->dev)
+		return -ENOMEM;
+
+	power->genpd = devm_kcalloc(dev, power->genpd_data.num_domains,
+				    sizeof(struct generic_pm_domain *),
+				    GFP_KERNEL);
+	if (!power->genpd)
+		return -ENOMEM;
+
+	power->genpd_data.domains = power->genpd;
+
+	ndom = 0;
+	for (entry = table; entry->name; entry++) {
+		struct bcm63xx_power_dev *pmd = &power->dev[ndom];
+		bool is_on;
+
+		pmd->power = power;
+		pmd->mask = BIT(entry->bit);
+		pmd->genpd.name = entry->name;
+		pmd->genpd.flags = entry->flags;
+
+		ret = bcm63xx_power_get_state(pmd, &is_on);
+		if (ret)
+			dev_warn(dev, "unable to get current state for %s\n",
+				 pmd->genpd.name);
+
+		pmd->genpd.power_on = bcm63xx_power_on;
+		pmd->genpd.power_off = bcm63xx_power_off;
+
+		pm_genpd_init(&pmd->genpd, NULL, !is_on);
+		power->genpd[entry->bit] = &pmd->genpd;
+
+		ndom++;
+	}
+
+	spin_lock_init(&power->lock);
+
+	ret = of_genpd_add_provider_onecell(np, &power->genpd_data);
+	if (ret) {
+		dev_err(dev, "failed to register genpd driver: %d\n", ret);
+		return ret;
+	}
+
+	dev_info(dev, "registered %u power domains\n", ndom);
+
+	return 0;
+}
+
+static const struct bcm63xx_power_data bcm6318_power_domains[] = {
+	{
+		.name = "pcie",
+		.bit = BCM6318_POWER_DOMAIN_PCIE,
+	}, {
+		.name = "usb",
+		.bit = BCM6318_POWER_DOMAIN_USB,
+	}, {
+		.name = "ephy0",
+		.bit = BCM6318_POWER_DOMAIN_EPHY0,
+	}, {
+		.name = "ephy1",
+		.bit = BCM6318_POWER_DOMAIN_EPHY1,
+	}, {
+		.name = "ephy2",
+		.bit = BCM6318_POWER_DOMAIN_EPHY2,
+	}, {
+		.name = "ephy3",
+		.bit = BCM6318_POWER_DOMAIN_EPHY3,
+	}, {
+		.name = "ldo2p5",
+		.bit = BCM6318_POWER_DOMAIN_LDO2P5,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "ldo2p9",
+		.bit = BCM6318_POWER_DOMAIN_LDO2P9,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "sw1p0",
+		.bit = BCM6318_POWER_DOMAIN_SW1P0,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "pad",
+		.bit = BCM6318_POWER_DOMAIN_PAD,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		/* sentinel */
+	},
+};
+
+static const struct bcm63xx_power_data bcm6328_power_domains[] = {
+	{
+		.name = "adsl2-mips",
+		.bit = BCM6328_POWER_DOMAIN_ADSL2_MIPS,
+	}, {
+		.name = "adsl2-phy",
+		.bit = BCM6328_POWER_DOMAIN_ADSL2_PHY,
+	}, {
+		.name = "adsl2-afe",
+		.bit = BCM6328_POWER_DOMAIN_ADSL2_AFE,
+	}, {
+		.name = "sar",
+		.bit = BCM6328_POWER_DOMAIN_SAR,
+	}, {
+		.name = "pcm",
+		.bit = BCM6328_POWER_DOMAIN_PCM,
+	}, {
+		.name = "usbd",
+		.bit = BCM6328_POWER_DOMAIN_USBD,
+	}, {
+		.name = "usbh",
+		.bit = BCM6328_POWER_DOMAIN_USBH,
+	}, {
+		.name = "pcie",
+		.bit = BCM6328_POWER_DOMAIN_PCIE,
+	}, {
+		.name = "robosw",
+		.bit = BCM6328_POWER_DOMAIN_ROBOSW,
+	}, {
+		.name = "ephy",
+		.bit = BCM6328_POWER_DOMAIN_EPHY,
+	}, {
+		/* sentinel */
+	},
+};
+
+static const struct bcm63xx_power_data bcm6362_power_domains[] = {
+	{
+		.name = "sar",
+		.bit = BCM6362_POWER_DOMAIN_SAR,
+	}, {
+		.name = "ipsec",
+		.bit = BCM6362_POWER_DOMAIN_IPSEC,
+	}, {
+		.name = "mips",
+		.bit = BCM6362_POWER_DOMAIN_MIPS,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "dect",
+		.bit = BCM6362_POWER_DOMAIN_DECT,
+	}, {
+		.name = "usbh",
+		.bit = BCM6362_POWER_DOMAIN_USBH,
+	}, {
+		.name = "usbd",
+		.bit = BCM6362_POWER_DOMAIN_USBD,
+	}, {
+		.name = "robosw",
+		.bit = BCM6362_POWER_DOMAIN_ROBOSW,
+	}, {
+		.name = "pcm",
+		.bit = BCM6362_POWER_DOMAIN_PCM,
+	}, {
+		.name = "periph",
+		.bit = BCM6362_POWER_DOMAIN_PERIPH,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "adsl-phy",
+		.bit = BCM6362_POWER_DOMAIN_ADSL_PHY,
+	}, {
+		.name = "gmii-pads",
+		.bit = BCM6362_POWER_DOMAIN_GMII_PADS,
+	}, {
+		.name = "fap",
+		.bit = BCM6362_POWER_DOMAIN_FAP,
+	}, {
+		.name = "pcie",
+		.bit = BCM6362_POWER_DOMAIN_PCIE,
+	}, {
+		.name = "wlan-pads",
+		.bit = BCM6362_POWER_DOMAIN_WLAN_PADS,
+	}, {
+		/* sentinel */
+	},
+};
+
+static const struct bcm63xx_power_data bcm63268_power_domains[] = {
+	{
+		.name = "sar",
+		.bit = BCM63268_POWER_DOMAIN_SAR,
+	}, {
+		.name = "ipsec",
+		.bit = BCM63268_POWER_DOMAIN_IPSEC,
+	}, {
+		.name = "mips",
+		.bit = BCM63268_POWER_DOMAIN_MIPS,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "dect",
+		.bit = BCM63268_POWER_DOMAIN_DECT,
+	}, {
+		.name = "usbh",
+		.bit = BCM63268_POWER_DOMAIN_USBH,
+	}, {
+		.name = "usbd",
+		.bit = BCM63268_POWER_DOMAIN_USBD,
+	}, {
+		.name = "robosw",
+		.bit = BCM63268_POWER_DOMAIN_ROBOSW,
+	}, {
+		.name = "pcm",
+		.bit = BCM63268_POWER_DOMAIN_PCM,
+	}, {
+		.name = "periph",
+		.bit = BCM63268_POWER_DOMAIN_PERIPH,
+		.flags = GENPD_FLAG_ALWAYS_ON,
+	}, {
+		.name = "vdsl-phy",
+		.bit = BCM63268_POWER_DOMAIN_VDSL_PHY,
+	}, {
+		.name = "vdsl-mips",
+		.bit = BCM63268_POWER_DOMAIN_VDSL_MIPS,
+	}, {
+		.name = "fap",
+		.bit = BCM63268_POWER_DOMAIN_FAP,
+	}, {
+		.name = "pcie",
+		.bit = BCM63268_POWER_DOMAIN_PCIE,
+	}, {
+		.name = "wlan-pads",
+		.bit = BCM63268_POWER_DOMAIN_WLAN_PADS,
+	}, {
+		/* sentinel */
+	},
+};
+
+static const struct of_device_id bcm63xx_power_of_match[] = {
+	{
+		.compatible = "brcm,bcm6318-power-controller",
+		.data = &bcm6318_power_domains,
+	}, {
+		.compatible = "brcm,bcm6328-power-controller",
+		.data = &bcm6328_power_domains,
+	}, {
+		.compatible = "brcm,bcm6362-power-controller",
+		.data = &bcm6362_power_domains,
+	}, {
+		.compatible = "brcm,bcm63268-power-controller",
+		.data = &bcm63268_power_domains,
+	}, {
+		/* sentinel */
+	}
+};
+
+static struct platform_driver bcm63xx_power_driver = {
+	.driver = {
+		.name = "bcm63xx-power-controller",
+		.of_match_table = bcm63xx_power_of_match,
+	},
+	.probe  = bcm63xx_power_probe,
+};
+builtin_platform_driver(bcm63xx_power_driver);