root/drivers/soc/ti/k3-socinfo.c
// SPDX-License-Identifier: GPL-2.0
/*
 * TI K3 SoC info driver
 *
 * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
 */

#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/regmap.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sys_soc.h>

#define CTRLMMR_WKUP_JTAGID_REG         0
/*
 * Bits:
 *  31-28 VARIANT       Device variant
 *  27-12 PARTNO        Part number
 *  11-1  MFG           Indicates TI as manufacturer (0x17)
 *  0                   Always 1
 */
#define CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT       (28)
#define CTRLMMR_WKUP_JTAGID_VARIANT_MASK        GENMASK(31, 28)

#define CTRLMMR_WKUP_JTAGID_PARTNO_SHIFT        (12)
#define CTRLMMR_WKUP_JTAGID_PARTNO_MASK         GENMASK(27, 12)

#define CTRLMMR_WKUP_JTAGID_MFG_SHIFT           (1)
#define CTRLMMR_WKUP_JTAGID_MFG_MASK            GENMASK(11, 1)

#define CTRLMMR_WKUP_JTAGID_MFG_TI              0x17

#define JTAG_ID_PARTNO_AM65X            0xBB5A
#define JTAG_ID_PARTNO_J721E            0xBB64
#define JTAG_ID_PARTNO_J7200            0xBB6D
#define JTAG_ID_PARTNO_AM64X            0xBB38
#define JTAG_ID_PARTNO_J721S2           0xBB75
#define JTAG_ID_PARTNO_AM62X            0xBB7E
#define JTAG_ID_PARTNO_J784S4           0xBB80
#define JTAG_ID_PARTNO_AM62AX           0xBB8D
#define JTAG_ID_PARTNO_AM62PX           0xBB9D
#define JTAG_ID_PARTNO_J722S            0xBBA0
#define JTAG_ID_PARTNO_AM62LX           0xBBA7

static const struct k3_soc_id {
        unsigned int id;
        const char *family_name;
} k3_soc_ids[] = {
        { JTAG_ID_PARTNO_AM65X, "AM65X" },
        { JTAG_ID_PARTNO_J721E, "J721E" },
        { JTAG_ID_PARTNO_J7200, "J7200" },
        { JTAG_ID_PARTNO_AM64X, "AM64X" },
        { JTAG_ID_PARTNO_J721S2, "J721S2"},
        { JTAG_ID_PARTNO_AM62X, "AM62X" },
        { JTAG_ID_PARTNO_J784S4, "J784S4" },
        { JTAG_ID_PARTNO_AM62AX, "AM62AX" },
        { JTAG_ID_PARTNO_AM62PX, "AM62PX" },
        { JTAG_ID_PARTNO_J722S, "J722S" },
        { JTAG_ID_PARTNO_AM62LX, "AM62LX" },
};

static const char * const j721e_rev_string_map[] = {
        "1.0", "1.1", "2.0",
};

static const char * const am62lx_rev_string_map[] = {
        "1.0", "1.1",
};

static int
k3_chipinfo_partno_to_names(unsigned int partno,
                            struct soc_device_attribute *soc_dev_attr)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(k3_soc_ids); i++)
                if (partno == k3_soc_ids[i].id) {
                        soc_dev_attr->family = k3_soc_ids[i].family_name;
                        return 0;
                }

        return -ENODEV;
}

static int
k3_chipinfo_variant_to_sr(unsigned int partno, unsigned int variant,
                          struct soc_device_attribute *soc_dev_attr)
{
        switch (partno) {
        case JTAG_ID_PARTNO_J721E:
                if (variant >= ARRAY_SIZE(j721e_rev_string_map))
                        goto err_unknown_variant;
                soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%s",
                                                   j721e_rev_string_map[variant]);
                break;
        case JTAG_ID_PARTNO_AM62LX:
                if (variant >= ARRAY_SIZE(am62lx_rev_string_map))
                        goto err_unknown_variant;
                soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%s",
                                                   am62lx_rev_string_map[variant]);
                break;
        default:
                variant++;
                soc_dev_attr->revision = kasprintf(GFP_KERNEL, "SR%x.0",
                                                   variant);
        }

        if (!soc_dev_attr->revision)
                return -ENOMEM;

        return 0;

err_unknown_variant:
        return -ENODEV;
}

static const struct regmap_config k3_chipinfo_regmap_cfg = {
        .reg_bits = 32,
        .val_bits = 32,
        .reg_stride = 4,
};

static int k3_chipinfo_probe(struct platform_device *pdev)
{
        struct device_node *node = pdev->dev.of_node;
        struct soc_device_attribute *soc_dev_attr;
        struct device *dev = &pdev->dev;
        struct soc_device *soc_dev;
        struct regmap *regmap;
        void __iomem *base;
        u32 partno_id;
        u32 variant;
        u32 jtag_id;
        u32 mfg;
        int ret;

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        regmap = devm_regmap_init_mmio(dev, base, &k3_chipinfo_regmap_cfg);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        ret = regmap_read(regmap, CTRLMMR_WKUP_JTAGID_REG, &jtag_id);
        if (ret < 0)
                return ret;

        mfg = (jtag_id & CTRLMMR_WKUP_JTAGID_MFG_MASK) >>
               CTRLMMR_WKUP_JTAGID_MFG_SHIFT;

        if (mfg != CTRLMMR_WKUP_JTAGID_MFG_TI) {
                dev_err(dev, "Invalid MFG SoC\n");
                return -ENODEV;
        }

        variant = (jtag_id & CTRLMMR_WKUP_JTAGID_VARIANT_MASK) >>
                  CTRLMMR_WKUP_JTAGID_VARIANT_SHIFT;

        partno_id = (jtag_id & CTRLMMR_WKUP_JTAGID_PARTNO_MASK) >>
                 CTRLMMR_WKUP_JTAGID_PARTNO_SHIFT;

        soc_dev_attr = kzalloc_obj(*soc_dev_attr);
        if (!soc_dev_attr)
                return -ENOMEM;

        ret = k3_chipinfo_partno_to_names(partno_id, soc_dev_attr);
        if (ret) {
                dev_err(dev, "Unknown SoC JTAGID[0x%08X]: %d\n", jtag_id, ret);
                goto err;
        }

        ret = k3_chipinfo_variant_to_sr(partno_id, variant, soc_dev_attr);
        if (ret) {
                dev_err(dev, "Unknown SoC SR[0x%08X]: %d\n", jtag_id, ret);
                goto err;
        }

        node = of_find_node_by_path("/");
        of_property_read_string(node, "model", &soc_dev_attr->machine);
        of_node_put(node);

        soc_dev = soc_device_register(soc_dev_attr);
        if (IS_ERR(soc_dev)) {
                ret = PTR_ERR(soc_dev);
                goto err_free_rev;
        }

        dev_info(dev, "Family:%s rev:%s JTAGID[0x%08x] Detected\n",
                 soc_dev_attr->family,
                 soc_dev_attr->revision, jtag_id);

        return 0;

err_free_rev:
        kfree(soc_dev_attr->revision);
err:
        kfree(soc_dev_attr);
        return ret;
}

static const struct of_device_id k3_chipinfo_of_match[] = {
        { .compatible = "ti,am654-chipid", },
        { /* sentinel */ },
};

static struct platform_driver k3_chipinfo_driver = {
        .driver = {
                .name = "k3-chipinfo",
                .of_match_table = k3_chipinfo_of_match,
        },
        .probe = k3_chipinfo_probe,
};

static int __init k3_chipinfo_init(void)
{
        return platform_driver_register(&k3_chipinfo_driver);
}
subsys_initcall(k3_chipinfo_init);