// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Freescale Semiconductor, Inc.
 * Copyright 2017-2018 NXP
 *      Dong Aisheng <aisheng.dong@nxp.com>
 *
 * Implementation of the SCU based Power Domains
 *
 * NOTE: a better implementation suggested by Ulf Hansson is using a
 * single global power domain and implement the ->attach|detach_dev()
 * callback for the genpd and use the regular of_genpd_add_provider_simple().
 * From within the ->attach_dev(), we could get the OF node for
 * the device that is being attached and then parse the power-domain
 * cell containing the "resource id" and store that in the per device
 * struct generic_pm_domain_data (we have void pointer there for
 * storing these kind of things).
 *
 * Additionally, we need to implement the ->stop() and ->start()
 * callbacks of genpd, which is where you "power on/off" devices,
 * rather than using the above ->power_on|off() callbacks.
 *
 * However, there're two known issues:
 * 1. The ->attach_dev() of power domain infrastructure still does
 *    not support multi domains case as the struct device *dev passed
 *    in is a virtual PD device, it does not help for parsing the real
 *    device resource id from device tree, so it's unware of which
 *    real sub power domain of device should be attached.
 *
 *    The framework needs some proper extension to support multi power
 *    domain cases.
 *
 * 2. It also breaks most of current drivers as the driver probe sequence
 *    behavior changed if removing ->power_on|off() callback and use
 *    ->start() and ->stop() instead. genpd_dev_pm_attach will only power
 *    up the domain and attach device, but will not call .start() which
 *    relies on device runtime pm. That means the device power is still
 *    not up before running driver probe function. For SCU enabled
 *    platforms, all device drivers accessing registers/clock without power
 *    domain enabled will trigger a HW access error. That means we need fix
 *    most drivers probe sequence with proper runtime pm.
 *
 * In summary, we need fix above two issue before being able to switch to
 * the "single global power domain" way.
 *
 */

#include <dt-bindings/firmware/imx/rsrc.h>
#include <linux/firmware/imx/sci.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_domain.h>
#include <linux/slab.h>

/* SCU Power Mode Protocol definition */
struct imx_sc_msg_req_set_resource_power_mode {
        struct imx_sc_rpc_msg hdr;
        u16 resource;
        u8 mode;
} __packed;

#define IMX_SCU_PD_NAME_SIZE 20
struct imx_sc_pm_domain {
        struct generic_pm_domain pd;
        char name[IMX_SCU_PD_NAME_SIZE];
        u32 rsrc;
};

struct imx_sc_pd_range {
        char *name;
        u32 rsrc;
        u8 num;
        bool postfix;
};

struct imx_sc_pd_soc {
        const struct imx_sc_pd_range *pd_ranges;
        u8 num_ranges;
};

static const struct imx_sc_pd_range imx8qxp_scu_pd_ranges[] = {
        /* LSIO SS */
        { "lsio-pwm", IMX_SC_R_PWM_0, 8, 1 },
        { "lsio-gpio", IMX_SC_R_GPIO_0, 8, 1 },
        { "lsio-gpt", IMX_SC_R_GPT_0, 5, 1 },
        { "lsio-kpp", IMX_SC_R_KPP, 1, 0 },
        { "lsio-fspi", IMX_SC_R_FSPI_0, 2, 1 },
        { "lsio-mu", IMX_SC_R_MU_0A, 14, 1 },

        /* CONN SS */
        { "con-usb", IMX_SC_R_USB_0, 2, 1 },
        { "con-usb0phy", IMX_SC_R_USB_0_PHY, 1, 0 },
        { "con-usb2", IMX_SC_R_USB_2, 1, 0 },
        { "con-usb2phy", IMX_SC_R_USB_2_PHY, 1, 0 },
        { "con-sdhc", IMX_SC_R_SDHC_0, 3, 1 },
        { "con-enet", IMX_SC_R_ENET_0, 2, 1 },
        { "con-nand", IMX_SC_R_NAND, 1, 0 },
        { "con-mlb", IMX_SC_R_MLB_0, 1, 1 },

        /* Audio DMA SS */
        { "adma-audio-pll0", IMX_SC_R_AUDIO_PLL_0, 1, 0 },
        { "adma-audio-pll1", IMX_SC_R_AUDIO_PLL_1, 1, 0 },
        { "adma-audio-clk-0", IMX_SC_R_AUDIO_CLK_0, 1, 0 },
        { "adma-dma0-ch", IMX_SC_R_DMA_0_CH0, 16, 1 },
        { "adma-dma1-ch", IMX_SC_R_DMA_1_CH0, 16, 1 },
        { "adma-dma2-ch", IMX_SC_R_DMA_2_CH0, 5, 1 },
        { "adma-asrc0", IMX_SC_R_ASRC_0, 1, 0 },
        { "adma-asrc1", IMX_SC_R_ASRC_1, 1, 0 },
        { "adma-esai0", IMX_SC_R_ESAI_0, 1, 0 },
        { "adma-spdif0", IMX_SC_R_SPDIF_0, 1, 0 },
        { "adma-sai", IMX_SC_R_SAI_0, 3, 1 },
        { "adma-amix", IMX_SC_R_AMIX, 1, 0 },
        { "adma-mqs0", IMX_SC_R_MQS_0, 1, 0 },
        { "adma-dsp", IMX_SC_R_DSP, 1, 0 },
        { "adma-dsp-ram", IMX_SC_R_DSP_RAM, 1, 0 },
        { "adma-can", IMX_SC_R_CAN_0, 3, 1 },
        { "adma-ftm", IMX_SC_R_FTM_0, 2, 1 },
        { "adma-lpi2c", IMX_SC_R_I2C_0, 4, 1 },
        { "adma-adc", IMX_SC_R_ADC_0, 1, 1 },
        { "adma-lcd", IMX_SC_R_LCD_0, 1, 1 },
        { "adma-lcd0-pwm", IMX_SC_R_LCD_0_PWM_0, 1, 1 },
        { "adma-lpuart", IMX_SC_R_UART_0, 4, 1 },
        { "adma-lpspi", IMX_SC_R_SPI_0, 4, 1 },

        /* VPU SS  */
        { "vpu", IMX_SC_R_VPU, 1, 0 },
        { "vpu-pid", IMX_SC_R_VPU_PID0, 8, 1 },
        { "vpu-dec0", IMX_SC_R_VPU_DEC_0, 1, 0 },
        { "vpu-enc0", IMX_SC_R_VPU_ENC_0, 1, 0 },

        /* GPU SS */
        { "gpu0-pid", IMX_SC_R_GPU_0_PID0, 4, 1 },

        /* HSIO SS */
        { "hsio-pcie-b", IMX_SC_R_PCIE_B, 1, 0 },
        { "hsio-serdes-1", IMX_SC_R_SERDES_1, 1, 0 },
        { "hsio-gpio", IMX_SC_R_HSIO_GPIO, 1, 0 },

        /* MIPI/LVDS SS */
        { "mipi0", IMX_SC_R_MIPI_0, 1, 0 },
        { "mipi0-pwm0", IMX_SC_R_MIPI_0_PWM_0, 1, 0 },
        { "mipi0-i2c", IMX_SC_R_MIPI_0_I2C_0, 2, 1 },
        { "lvds0", IMX_SC_R_LVDS_0, 1, 0 },

        /* DC SS */
        { "dc0", IMX_SC_R_DC_0, 1, 0 },
        { "dc0-pll", IMX_SC_R_DC_0_PLL_0, 2, 1 },
};

static const struct imx_sc_pd_soc imx8qxp_scu_pd = {
        .pd_ranges = imx8qxp_scu_pd_ranges,
        .num_ranges = ARRAY_SIZE(imx8qxp_scu_pd_ranges),
};

static struct imx_sc_ipc *pm_ipc_handle;

static inline struct imx_sc_pm_domain *
to_imx_sc_pd(struct generic_pm_domain *genpd)
{
        return container_of(genpd, struct imx_sc_pm_domain, pd);
}

static int imx_sc_pd_power(struct generic_pm_domain *domain, bool power_on)
{
        struct imx_sc_msg_req_set_resource_power_mode msg;
        struct imx_sc_rpc_msg *hdr = &msg.hdr;
        struct imx_sc_pm_domain *pd;
        int ret;

        pd = to_imx_sc_pd(domain);

        hdr->ver = IMX_SC_RPC_VERSION;
        hdr->svc = IMX_SC_RPC_SVC_PM;
        hdr->func = IMX_SC_PM_FUNC_SET_RESOURCE_POWER_MODE;
        hdr->size = 2;

        msg.resource = pd->rsrc;
        msg.mode = power_on ? IMX_SC_PM_PW_MODE_ON : IMX_SC_PM_PW_MODE_LP;

        ret = imx_scu_call_rpc(pm_ipc_handle, &msg, true);
        if (ret)
                dev_err(&domain->dev, "failed to power %s resource %d ret %d\n",
                        power_on ? "up" : "off", pd->rsrc, ret);

        return ret;
}

static int imx_sc_pd_power_on(struct generic_pm_domain *domain)
{
        return imx_sc_pd_power(domain, true);
}

static int imx_sc_pd_power_off(struct generic_pm_domain *domain)
{
        return imx_sc_pd_power(domain, false);
}

static struct generic_pm_domain *imx_scu_pd_xlate(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 < pd_data->num_domains; i++) {
                struct imx_sc_pm_domain *sc_pd;

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

        return domain;
}

static struct imx_sc_pm_domain *
imx_scu_add_pm_domain(struct device *dev, int idx,
                      const struct imx_sc_pd_range *pd_ranges)
{
        struct imx_sc_pm_domain *sc_pd;
        int ret;

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

        sc_pd->rsrc = pd_ranges->rsrc + idx;
        sc_pd->pd.power_off = imx_sc_pd_power_off;
        sc_pd->pd.power_on = imx_sc_pd_power_on;

        if (pd_ranges->postfix)
                snprintf(sc_pd->name, sizeof(sc_pd->name),
                         "%s%i", pd_ranges->name, idx);
        else
                snprintf(sc_pd->name, sizeof(sc_pd->name),
                         "%s", pd_ranges->name);

        sc_pd->pd.name = sc_pd->name;

        if (sc_pd->rsrc >= IMX_SC_R_LAST) {
                dev_warn(dev, "invalid pd %s rsrc id %d found",
                         sc_pd->name, sc_pd->rsrc);

                devm_kfree(dev, sc_pd);
                return NULL;
        }

        ret = pm_genpd_init(&sc_pd->pd, NULL, true);
        if (ret) {
                dev_warn(dev, "failed to init pd %s rsrc id %d",
                         sc_pd->name, sc_pd->rsrc);
                devm_kfree(dev, sc_pd);
                return NULL;
        }

        return sc_pd;
}

static int imx_scu_init_pm_domains(struct device *dev,
                                    const struct imx_sc_pd_soc *pd_soc)
{
        const struct imx_sc_pd_range *pd_ranges = pd_soc->pd_ranges;
        struct generic_pm_domain **domains;
        struct genpd_onecell_data *pd_data;
        struct imx_sc_pm_domain *sc_pd;
        u32 count = 0;
        int i, j;

        for (i = 0; i < pd_soc->num_ranges; i++)
                count += pd_ranges[i].num;

        domains = devm_kcalloc(dev, count, sizeof(*domains), GFP_KERNEL);
        if (!domains)
                return -ENOMEM;

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

        count = 0;
        for (i = 0; i < pd_soc->num_ranges; i++) {
                for (j = 0; j < pd_ranges[i].num; j++) {
                        sc_pd = imx_scu_add_pm_domain(dev, j, &pd_ranges[i]);
                        if (IS_ERR_OR_NULL(sc_pd))
                                continue;

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

        pd_data->domains = domains;
        pd_data->num_domains = count;
        pd_data->xlate = imx_scu_pd_xlate;

        of_genpd_add_provider_onecell(dev->of_node, pd_data);

        return 0;
}

static int imx_sc_pd_probe(struct platform_device *pdev)
{
        const struct imx_sc_pd_soc *pd_soc;
        int ret;

        ret = imx_scu_get_handle(&pm_ipc_handle);
        if (ret)
                return ret;

        pd_soc = of_device_get_match_data(&pdev->dev);
        if (!pd_soc)
                return -ENODEV;

        return imx_scu_init_pm_domains(&pdev->dev, pd_soc);
}

static const struct of_device_id imx_sc_pd_match[] = {
        { .compatible = "fsl,imx8qxp-scu-pd", &imx8qxp_scu_pd},
        { /* sentinel */ }
};

static struct platform_driver imx_sc_pd_driver = {
        .driver = {
                .name = "imx-scu-pd",
                .of_match_table = imx_sc_pd_match,
        },
        .probe = imx_sc_pd_probe,
};
builtin_platform_driver(imx_sc_pd_driver);

MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
MODULE_DESCRIPTION("IMX SCU Power Domain driver");
MODULE_LICENSE("GPL v2");