soc: bcm: add PM driver for Broadcom's PMB

PMB originally comes from BCM63138 but can be also found on many other
chipsets (e.g. BCM4908). It's needed to power on and off SoC blocks like
PCIe, SATA, USB.

Signed-off-by: Rafał Miłecki <[e-mail]>
Acked-by: Ulf Hansson <[e-mail]>
Signed-off-by: Florian Fainelli <[e-mail]>

MAINTAINERS

···
 S:	Maintained
 F:	drivers/firmware/broadcom/*
 
+BROADCOM PMB (POWER MANAGEMENT BUS) DRIVER
+M:	Rafał Miłecki <[e-mail]>
+M:	Florian Fainelli <[e-mail]>
+M:	[e-mail]
+L:	[e-mail]
+S:	Maintained
+T:	git git://github.com/broadcom/stblinux.git
+F:	drivers/soc/bcm/bcm-pmb.c
+F:	include/dt-bindings/soc/bcm-pmb.h
+
 BROADCOM SPECIFIC AMBA DRIVER (BCMA)
 M:	Rafał Miłecki <[e-mail]>
 L:	[e-mail]

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-$(CONFIG_SOC_BCM63XX)	+= bcm63xx/
+obj-y				+= bcm63xx/
 obj-$(CONFIG_SOC_BRCMSTB)	+= brcmstb/

drivers/soc/bcm/bcm63xx/Kconfig

···
 	  BCM6318, BCM6328, BCM6362 and BCM63268 SoCs.
 
 endif # SOC_BCM63XX
+
+config BCM_PMB
+	bool "Broadcom PMB (Power Management Bus) driver"
+	depends on ARCH_BCM4908 || (COMPILE_TEST && OF)
+	default ARCH_BCM4908
+	select PM_GENERIC_DOMAINS if PM
+	help
+	  This enables support for the Broadcom's PMB (Power Management Bus) that
+	  is used for disabling and enabling SoC devices.

drivers/soc/bcm/bcm63xx/Makefile

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

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

···
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2013 Broadcom
+ * Copyright (C) 2020 Rafał Miłecki <[e-mail]>
+ */
+
+#include <dt-bindings/soc/bcm-pmb.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/reset/bcm63xx_pmb.h>
+
+#define BPCM_ID_REG					0x00
+#define BPCM_CAPABILITIES				0x04
+#define  BPCM_CAP_NUM_ZONES				0x000000ff
+#define  BPCM_CAP_SR_REG_BITS				0x0000ff00
+#define  BPCM_CAP_PLLTYPE				0x00030000
+#define  BPCM_CAP_UBUS					0x00080000
+#define BPCM_CONTROL					0x08
+#define BPCM_STATUS					0x0c
+#define BPCM_ROSC_CONTROL				0x10
+#define BPCM_ROSC_THRESH_H				0x14
+#define BPCM_ROSC_THRESHOLD_BCM6838			0x14
+#define BPCM_ROSC_THRESH_S				0x18
+#define BPCM_ROSC_COUNT_BCM6838				0x18
+#define BPCM_ROSC_COUNT					0x1c
+#define BPCM_PWD_CONTROL_BCM6838			0x1c
+#define BPCM_PWD_CONTROL				0x20
+#define BPCM_SR_CONTROL_BCM6838				0x20
+#define BPCM_PWD_ACCUM_CONTROL				0x24
+#define BPCM_SR_CONTROL					0x28
+#define BPCM_GLOBAL_CONTROL				0x2c
+#define BPCM_MISC_CONTROL				0x30
+#define BPCM_MISC_CONTROL2				0x34
+#define BPCM_SGPHY_CNTL					0x38
+#define BPCM_SGPHY_STATUS				0x3c
+#define BPCM_ZONE0					0x40
+#define  BPCM_ZONE_CONTROL				0x00
+#define   BPCM_ZONE_CONTROL_MANUAL_CLK_EN		0x00000001
+#define   BPCM_ZONE_CONTROL_MANUAL_RESET_CTL		0x00000002
+#define   BPCM_ZONE_CONTROL_FREQ_SCALE_USED		0x00000004	/* R/O */
+#define   BPCM_ZONE_CONTROL_DPG_CAPABLE			0x00000008	/* R/O */
+#define   BPCM_ZONE_CONTROL_MANUAL_MEM_PWR		0x00000030
+#define   BPCM_ZONE_CONTROL_MANUAL_ISO_CTL		0x00000040
+#define   BPCM_ZONE_CONTROL_MANUAL_CTL			0x00000080
+#define   BPCM_ZONE_CONTROL_DPG_CTL_EN			0x00000100
+#define   BPCM_ZONE_CONTROL_PWR_DN_REQ			0x00000200
+#define   BPCM_ZONE_CONTROL_PWR_UP_REQ			0x00000400
+#define   BPCM_ZONE_CONTROL_MEM_PWR_CTL_EN		0x00000800
+#define   BPCM_ZONE_CONTROL_BLK_RESET_ASSERT		0x00001000
+#define   BPCM_ZONE_CONTROL_MEM_STBY			0x00002000
+#define   BPCM_ZONE_CONTROL_RESERVED			0x0007c000
+#define   BPCM_ZONE_CONTROL_PWR_CNTL_STATE		0x00f80000
+#define   BPCM_ZONE_CONTROL_FREQ_SCALAR_DYN_SEL		0x01000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_PWR_OFF_STATE		0x02000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_PWR_ON_STATE		0x04000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_PWR_GOOD			0x08000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_DPG_PWR_STATE		0x10000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_MEM_PWR_STATE		0x20000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_ISO_STATE			0x40000000	/* R/O */
+#define   BPCM_ZONE_CONTROL_RESET_STATE			0x80000000	/* R/O */
+#define  BPCM_ZONE_CONFIG1				0x04
+#define  BPCM_ZONE_CONFIG2				0x08
+#define  BPCM_ZONE_FREQ_SCALAR_CONTROL			0x0c
+#define  BPCM_ZONE_SIZE					0x10
+
+struct bcm_pmb {
+	struct device *dev;
+	void __iomem *base;
+	spinlock_t lock;
+	bool little_endian;
+	struct genpd_onecell_data genpd_onecell_data;
+};
+
+struct bcm_pmb_pd_data {
+	const char * const name;
+	int id;
+	u8 bus;
+	u8 device;
+};
+
+struct bcm_pmb_pm_domain {
+	struct bcm_pmb *pmb;
+	const struct bcm_pmb_pd_data *data;
+	struct generic_pm_domain genpd;
+};
+
+static int bcm_pmb_bpcm_read(struct bcm_pmb *pmb, int bus, u8 device,
+			     int offset, u32 *val)
+{
+	void __iomem *base = pmb->base + bus * 0x20;
+	unsigned long flags;
+	int err;
+
+	spin_lock_irqsave(&pmb->lock, flags);
+	err = bpcm_rd(base, device, offset, val);
+	spin_unlock_irqrestore(&pmb->lock, flags);
+
+	if (!err)
+		*val = pmb->little_endian ? le32_to_cpu(*val) : be32_to_cpu(*val);
+
+	return err;
+}
+
+static int bcm_pmb_bpcm_write(struct bcm_pmb *pmb, int bus, u8 device,
+			      int offset, u32 val)
+{
+	void __iomem *base = pmb->base + bus * 0x20;
+	unsigned long flags;
+	int err;
+
+	val = pmb->little_endian ? cpu_to_le32(val) : cpu_to_be32(val);
+
+	spin_lock_irqsave(&pmb->lock, flags);
+	err = bpcm_wr(base, device, offset, val);
+	spin_unlock_irqrestore(&pmb->lock, flags);
+
+	return err;
+}
+
+static int bcm_pmb_power_off_zone(struct bcm_pmb *pmb, int bus, u8 device,
+				  int zone)
+{
+	int offset;
+	u32 val;
+	int err;
+
+	offset = BPCM_ZONE0 + zone * BPCM_ZONE_SIZE + BPCM_ZONE_CONTROL;
+
+	err = bcm_pmb_bpcm_read(pmb, bus, device, offset, &val);
+	if (err)
+		return err;
+
+	val |= BPCM_ZONE_CONTROL_PWR_DN_REQ;
+	val &= ~BPCM_ZONE_CONTROL_PWR_UP_REQ;
+
+	err = bcm_pmb_bpcm_write(pmb, bus, device, offset, val);
+
+	return err;
+}
+
+static int bcm_pmb_power_on_zone(struct bcm_pmb *pmb, int bus, u8 device,
+				 int zone)
+{
+	int offset;
+	u32 val;
+	int err;
+
+	offset = BPCM_ZONE0 + zone * BPCM_ZONE_SIZE + BPCM_ZONE_CONTROL;
+
+	err = bcm_pmb_bpcm_read(pmb, bus, device, offset, &val);
+	if (err)
+		return err;
+
+	if (!(val & BPCM_ZONE_CONTROL_PWR_ON_STATE)) {
+		val &= ~BPCM_ZONE_CONTROL_PWR_DN_REQ;
+		val |= BPCM_ZONE_CONTROL_DPG_CTL_EN;
+		val |= BPCM_ZONE_CONTROL_PWR_UP_REQ;
+		val |= BPCM_ZONE_CONTROL_MEM_PWR_CTL_EN;
+		val |= BPCM_ZONE_CONTROL_BLK_RESET_ASSERT;
+
+		err = bcm_pmb_bpcm_write(pmb, bus, device, offset, val);
+	}
+
+	return err;
+}
+
+static int bcm_pmb_power_off_device(struct bcm_pmb *pmb, int bus, u8 device)
+{
+	int offset;
+	u32 val;
+	int err;
+
+	/* Entire device can be powered off by powering off the 0th zone */
+	offset = BPCM_ZONE0 + BPCM_ZONE_CONTROL;
+
+	err = bcm_pmb_bpcm_read(pmb, bus, device, offset, &val);
+	if (err)
+		return err;
+
+	if (!(val & BPCM_ZONE_CONTROL_PWR_OFF_STATE)) {
+		val = BPCM_ZONE_CONTROL_PWR_DN_REQ;
+
+		err = bcm_pmb_bpcm_write(pmb, bus, device, offset, val);
+	}
+
+	return err;
+}
+
+static int bcm_pmb_power_on_device(struct bcm_pmb *pmb, int bus, u8 device)
+{
+	u32 val;
+	int err;
+	int i;
+
+	err = bcm_pmb_bpcm_read(pmb, bus, device, BPCM_CAPABILITIES, &val);
+	if (err)
+		return err;
+
+	for (i = 0; i < (val & BPCM_CAP_NUM_ZONES); i++) {
+		err = bcm_pmb_power_on_zone(pmb, bus, device, i);
+		if (err)
+			return err;
+	}
+
+	return err;
+}
+
+static int bcm_pmb_power_on(struct generic_pm_domain *genpd)
+{
+	struct bcm_pmb_pm_domain *pd = container_of(genpd, struct bcm_pmb_pm_domain, genpd);
+	const struct bcm_pmb_pd_data *data = pd->data;
+	struct bcm_pmb *pmb = pd->pmb;
+
+	switch (data->id) {
+	case BCM_PMB_PCIE0:
+	case BCM_PMB_PCIE1:
+	case BCM_PMB_PCIE2:
+		return bcm_pmb_power_on_zone(pmb, data->bus, data->device, 0);
+	case BCM_PMB_HOST_USB:
+		return bcm_pmb_power_on_device(pmb, data->bus, data->device);
+	default:
+		dev_err(pmb->dev, "unsupported device id: %d\n", data->id);
+		return -EINVAL;
+	}
+}
+
+static int bcm_pmb_power_off(struct generic_pm_domain *genpd)
+{
+	struct bcm_pmb_pm_domain *pd = container_of(genpd, struct bcm_pmb_pm_domain, genpd);
+	const struct bcm_pmb_pd_data *data = pd->data;
+	struct bcm_pmb *pmb = pd->pmb;
+
+	switch (data->id) {
+	case BCM_PMB_PCIE0:
+	case BCM_PMB_PCIE1:
+	case BCM_PMB_PCIE2:
+		return bcm_pmb_power_off_zone(pmb, data->bus, data->device, 0);
+	case BCM_PMB_HOST_USB:
+		return bcm_pmb_power_off_device(pmb, data->bus, data->device);
+	default:
+		dev_err(pmb->dev, "unsupported device id: %d\n", data->id);
+		return -EINVAL;
+	}
+}
+
+static int bcm_pmb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct bcm_pmb_pd_data *table;
+	const struct bcm_pmb_pd_data *e;
+	struct resource *res;
+	struct bcm_pmb *pmb;
+	int max_id;
+	int err;
+
+	pmb = devm_kzalloc(dev, sizeof(*pmb), GFP_KERNEL);
+	if (!pmb)
+		return -ENOMEM;
+
+	pmb->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pmb->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pmb->base))
+		return PTR_ERR(pmb->base);
+
+	spin_lock_init(&pmb->lock);
+
+	pmb->little_endian = !of_device_is_big_endian(dev->of_node);
+
+	table = of_device_get_match_data(dev);
+	if (!table)
+		return -EINVAL;
+
+	max_id = 0;
+	for (e = table; e->name; e++)
+		max_id = max(max_id, e->id);
+
+	pmb->genpd_onecell_data.num_domains = max_id + 1;
+	pmb->genpd_onecell_data.domains =
+		devm_kcalloc(dev, pmb->genpd_onecell_data.num_domains,
+			     sizeof(struct generic_pm_domain *), GFP_KERNEL);
+	if (!pmb->genpd_onecell_data.domains)
+		return -ENOMEM;
+
+	for (e = table; e->name; e++) {
+		struct bcm_pmb_pm_domain *pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+
+		pd->pmb = pmb;
+		pd->data = e;
+		pd->genpd.name = e->name;
+		pd->genpd.power_on = bcm_pmb_power_on;
+		pd->genpd.power_off = bcm_pmb_power_off;
+
+		pm_genpd_init(&pd->genpd, NULL, true);
+		pmb->genpd_onecell_data.domains[e->id] = &pd->genpd;
+	}
+
+	err = of_genpd_add_provider_onecell(dev->of_node, &pmb->genpd_onecell_data);
+	if (err) {
+		dev_err(dev, "failed to add genpd provider: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static const struct bcm_pmb_pd_data bcm_pmb_bcm4908_data[] = {
+	{ .name = "pcie2", .id = BCM_PMB_PCIE2, .bus = 0, .device = 2, },
+	{ .name = "pcie0", .id = BCM_PMB_PCIE0, .bus = 1, .device = 14, },
+	{ .name = "pcie1", .id = BCM_PMB_PCIE1, .bus = 1, .device = 15, },
+	{ .name = "usb", .id = BCM_PMB_HOST_USB, .bus = 1, .device = 17, },
+	{ },
+};
+
+static const struct of_device_id bcm_pmb_of_match[] = {
+	{ .compatible = "brcm,bcm4908-pmb", .data = &bcm_pmb_bcm4908_data, },
+	{ },
+};
+
+static struct platform_driver bcm_pmb_driver = {
+	.driver = {
+		.name = "bcm-pmb",
+		.of_match_table = bcm_pmb_of_match,
+	},
+	.probe  = bcm_pmb_probe,
+};
+
+builtin_platform_driver(bcm_pmb_driver);