// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Alibaba Group Holding Limited.
 * Copyright (c) 2024 Samsung Electronics Co., Ltd.
 * Author: Michal Wilczynski <m.wilczynski@samsung.com>
 */

#include <linux/auxiliary_bus.h>
#include <linux/firmware/thead/thead,th1520-aon.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>

#include <dt-bindings/power/thead,th1520-power.h>

struct th1520_power_domain {
        struct th1520_aon_chan *aon_chan;
        struct generic_pm_domain genpd;
        u32 rsrc;
};

struct th1520_power_info {
        const char *name;
        u32 rsrc;
        bool disabled;
};

/*
 * The AUDIO power domain is marked as disabled to prevent the driver from
 * managing its power state. Direct AON firmware calls to control this power
 * island trigger a firmware bug causing system instability. Until this
 * firmware issue is resolved, the AUDIO power domain must remain disabled
 * to avoid crashes.
 */
static const struct th1520_power_info th1520_pd_ranges[] = {
        [TH1520_AUDIO_PD] = {"audio", TH1520_AON_AUDIO_PD, true },
        [TH1520_VDEC_PD] = { "vdec", TH1520_AON_VDEC_PD, false },
        [TH1520_NPU_PD] = { "npu", TH1520_AON_NPU_PD, false },
        [TH1520_VENC_PD] = { "venc", TH1520_AON_VENC_PD, false },
        [TH1520_GPU_PD] = { "gpu", TH1520_AON_GPU_PD, false },
        [TH1520_DSP0_PD] = { "dsp0", TH1520_AON_DSP0_PD, false },
        [TH1520_DSP1_PD] = { "dsp1", TH1520_AON_DSP1_PD, false }
};

static inline struct th1520_power_domain *
to_th1520_power_domain(struct generic_pm_domain *genpd)
{
        return container_of(genpd, struct th1520_power_domain, genpd);
}

static int th1520_pd_power_on(struct generic_pm_domain *domain)
{
        struct th1520_power_domain *pd = to_th1520_power_domain(domain);

        return th1520_aon_power_update(pd->aon_chan, pd->rsrc, true);
}

static int th1520_pd_power_off(struct generic_pm_domain *domain)
{
        struct th1520_power_domain *pd = to_th1520_power_domain(domain);

        return th1520_aon_power_update(pd->aon_chan, pd->rsrc, false);
}

static struct generic_pm_domain *th1520_pd_xlate(const struct of_phandle_args *spec,
                                                 void *data)
{
        struct generic_pm_domain *domain = ERR_PTR(-ENOENT);
        struct genpd_onecell_data *pd_data = data;
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(th1520_pd_ranges); i++) {
                struct th1520_power_domain *pd;

                if (th1520_pd_ranges[i].disabled)
                        continue;

                pd = to_th1520_power_domain(pd_data->domains[i]);
                if (pd->rsrc == spec->args[0]) {
                        domain = &pd->genpd;
                        break;
                }
        }

        return domain;
}

static struct th1520_power_domain *
th1520_add_pm_domain(struct device *dev, const struct th1520_power_info *pi)
{
        struct th1520_power_domain *pd;
        int ret;

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

        pd->rsrc = pi->rsrc;
        pd->genpd.power_on = th1520_pd_power_on;
        pd->genpd.power_off = th1520_pd_power_off;
        pd->genpd.name = pi->name;

        ret = pm_genpd_init(&pd->genpd, NULL, true);
        if (ret)
                return ERR_PTR(ret);

        return pd;
}

static void th1520_pd_init_all_off(struct generic_pm_domain **domains,
                                   struct device *dev)
{
        int ret;
        int i;

        for (i = 0; i < ARRAY_SIZE(th1520_pd_ranges); i++) {
                struct th1520_power_domain *pd;

                if (th1520_pd_ranges[i].disabled)
                        continue;

                pd = to_th1520_power_domain(domains[i]);

                ret = th1520_aon_power_update(pd->aon_chan, pd->rsrc, false);
                if (ret)
                        dev_err(dev,
                                "Failed to initially power down power domain %s\n",
                                pd->genpd.name);
        }
}

static void th1520_pd_pwrseq_unregister_adev(void *adev)
{
        auxiliary_device_delete(adev);
        auxiliary_device_uninit(adev);
}

static int th1520_pd_pwrseq_gpu_init(struct device *dev)
{
        struct auxiliary_device *adev;
        int ret;

        /*
         * Correctly check only for the property's existence in the DT node.
         * We don't need to get/claim the reset here; that is the job of
         * the auxiliary driver that we are about to spawn.
         */
        if (device_property_match_string(dev, "reset-names", "gpu-clkgen") < 0)
                /*
                 * This is not an error. It simply means the optional sequencer
                 * is not described in the device tree.
                 */
                return 0;

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

        adev->name = "pwrseq-gpu";
        adev->dev.parent = dev;

        ret = auxiliary_device_init(adev);
        if (ret)
                return ret;

        ret = auxiliary_device_add(adev);
        if (ret) {
                auxiliary_device_uninit(adev);
                return ret;
        }

        return devm_add_action_or_reset(dev, th1520_pd_pwrseq_unregister_adev,
                                        adev);
}

static int th1520_pd_reboot_init(struct device *dev,
                                 struct th1520_aon_chan *aon_chan)
{
        struct auxiliary_device *adev;

        adev = devm_auxiliary_device_create(dev, "reboot", aon_chan);
        if (!adev)
                return -ENODEV;

        return 0;
}

static int th1520_pd_probe(struct platform_device *pdev)
{
        struct generic_pm_domain **domains;
        struct genpd_onecell_data *pd_data;
        struct th1520_aon_chan *aon_chan;
        struct device *dev = &pdev->dev;
        int i, ret;

        aon_chan = th1520_aon_init(dev);
        if (IS_ERR(aon_chan))
                return dev_err_probe(dev, PTR_ERR(aon_chan),
                                     "Failed to get AON channel\n");

        domains = devm_kcalloc(dev, ARRAY_SIZE(th1520_pd_ranges),
                               sizeof(*domains), GFP_KERNEL);
        if (!domains) {
                ret = -ENOMEM;
                goto err_clean_aon;
        }

        pd_data = devm_kzalloc(dev, sizeof(*pd_data), GFP_KERNEL);
        if (!pd_data) {
                ret = -ENOMEM;
                goto err_clean_aon;
        }

        for (i = 0; i < ARRAY_SIZE(th1520_pd_ranges); i++) {
                struct th1520_power_domain *pd;

                if (th1520_pd_ranges[i].disabled)
                        continue;

                pd = th1520_add_pm_domain(dev, &th1520_pd_ranges[i]);
                if (IS_ERR(pd)) {
                        ret = PTR_ERR(pd);
                        goto err_clean_genpd;
                }

                pd->aon_chan = aon_chan;
                domains[i] = &pd->genpd;
                dev_dbg(dev, "added power domain %s\n", pd->genpd.name);
        }

        pd_data->domains = domains;
        pd_data->num_domains = ARRAY_SIZE(th1520_pd_ranges);
        pd_data->xlate = th1520_pd_xlate;

        /*
         * Initialize all power domains to off to ensure they start in a
         * low-power state. This allows device drivers to manage power
         * domains by turning them on or off as needed.
         */
        th1520_pd_init_all_off(domains, dev);

        ret = of_genpd_add_provider_onecell(dev->of_node, pd_data);
        if (ret)
                goto err_clean_genpd;

        ret = th1520_pd_pwrseq_gpu_init(dev);
        if (ret)
                goto err_clean_provider;

        ret = th1520_pd_reboot_init(dev, aon_chan);
        if (ret)
                goto err_clean_provider;

        return 0;

err_clean_provider:
        of_genpd_del_provider(dev->of_node);
err_clean_genpd:
        for (i--; i >= 0; i--)
                pm_genpd_remove(domains[i]);
err_clean_aon:
        th1520_aon_deinit(aon_chan);

        return ret;
}

static const struct of_device_id th1520_pd_match[] = {
        { .compatible = "thead,th1520-aon" },
        { /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, th1520_pd_match);

static struct platform_driver th1520_pd_driver = {
        .driver = {
                .name = "th1520-pd",
                .of_match_table = th1520_pd_match,
                .suppress_bind_attrs = true,
        },
        .probe = th1520_pd_probe,
};
module_platform_driver(th1520_pd_driver);

MODULE_AUTHOR("Michal Wilczynski <m.wilczynski@samsung.com>");
MODULE_DESCRIPTION("T-HEAD TH1520 SoC power domain controller");
MODULE_LICENSE("GPL");