root/drivers/pmdomain/bcm/bcm-pmb.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2013 Broadcom
 * Copyright (C) 2020 Rafał Miłecki <rafal@milecki.pl>
 */

#include <dt-bindings/soc/bcm-pmb.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.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_sata(struct bcm_pmb *pmb, int bus, u8 device)
{
        int err;

        err = bcm_pmb_power_on_zone(pmb, bus, device, 0);
        if (err)
                return err;

        /* Does not apply to the BCM963158 */
        err = bcm_pmb_bpcm_write(pmb, bus, device, BPCM_MISC_CONTROL, 0);
        if (err)
                return err;

        err = bcm_pmb_bpcm_write(pmb, bus, device, BPCM_SR_CONTROL, 0xffffffff);
        if (err)
                return err;

        err = bcm_pmb_bpcm_write(pmb, bus, device, BPCM_SR_CONTROL, 0);

        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);
        case BCM_PMB_SATA:
                return bcm_pmb_power_on_sata(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 bcm_pmb *pmb;
        int max_id;
        int err;

        pmb = devm_kzalloc(dev, sizeof(*pmb), GFP_KERNEL);
        if (!pmb)
                return -ENOMEM;

        pmb->dev = dev;

        pmb->base = devm_platform_ioremap_resource(pdev, 0);
        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);

                if (!pd)
                        return -ENOMEM;

                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 bcm_pmb_pd_data bcm_pmb_bcm63138_data[] = {
        { .name = "sata", .id = BCM_PMB_SATA, .bus = 0, .device = 3, },
        { },
};

static const struct of_device_id bcm_pmb_of_match[] = {
        { .compatible = "brcm,bcm4908-pmb", .data = &bcm_pmb_bcm4908_data, },
        { .compatible = "brcm,bcm63138-pmb", .data = &bcm_pmb_bcm63138_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);