root/drivers/clk/renesas/clk-sh73a0.c
// SPDX-License-Identifier: GPL-2.0
/*
 * sh73a0 Core CPG Clocks
 *
 * Copyright (C) 2014  Ulrich Hecht
 */

#include <linux/clk-provider.h>
#include <linux/clk/renesas.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

struct sh73a0_cpg {
        struct clk_onecell_data data;
        spinlock_t lock;
};

#define CPG_FRQCRA      0x00
#define CPG_FRQCRB      0x04
#define CPG_SD0CKCR     0x74
#define CPG_SD1CKCR     0x78
#define CPG_SD2CKCR     0x7c
#define CPG_PLLECR      0xd0
#define CPG_PLL0CR      0xd8
#define CPG_PLL1CR      0x28
#define CPG_PLL2CR      0x2c
#define CPG_PLL3CR      0xdc
#define CPG_CKSCR       0xc0
#define CPG_DSI0PHYCR   0x6c
#define CPG_DSI1PHYCR   0x70

struct div4_clk {
        const char *name;
        const char *parent;
        unsigned int reg;
        unsigned int shift;
};

static const struct div4_clk div4_clks[] = {
        { "zg", "pll0", CPG_FRQCRA, 16 },
        { "m3", "pll1", CPG_FRQCRA, 12 },
        { "b",  "pll1", CPG_FRQCRA,  8 },
        { "m1", "pll1", CPG_FRQCRA,  4 },
        { "m2", "pll1", CPG_FRQCRA,  0 },
        { "zx", "pll1", CPG_FRQCRB, 12 },
        { "hp", "pll1", CPG_FRQCRB,  4 },
        { NULL, NULL, 0, 0 },
};

static const struct clk_div_table div4_div_table[] = {
        { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
        { 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
        { 12, 7 }, { 0, 0 }
};

static const struct clk_div_table z_div_table[] = {
        /* ZSEL == 0 */
        { 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }, { 4, 1 }, { 5, 1 },
        { 6, 1 }, { 7, 1 }, { 8, 1 }, { 9, 1 }, { 10, 1 }, { 11, 1 },
        { 12, 1 }, { 13, 1 }, { 14, 1 }, { 15, 1 },
        /* ZSEL == 1 */
        { 16, 2 }, { 17, 3 }, { 18, 4 }, { 19, 6 }, { 20, 8 }, { 21, 12 },
        { 22, 16 }, { 24, 24 }, { 27, 48 }, { 0, 0 }
};

static struct clk * __init
sh73a0_cpg_register_clock(struct device_node *np, struct sh73a0_cpg *cpg,
                          void __iomem *base, const char *name)
{
        const struct clk_div_table *table = NULL;
        unsigned int shift, reg, width;
        const char *parent_name = NULL;
        unsigned int mult = 1;
        unsigned int div = 1;

        if (!strcmp(name, "main")) {
                /* extal1, extal1_div2, extal2, extal2_div2 */
                u32 parent_idx = (readl(base + CPG_CKSCR) >> 28) & 3;

                parent_name = of_clk_get_parent_name(np, parent_idx >> 1);
                div = (parent_idx & 1) + 1;
        } else if (!strncmp(name, "pll", 3)) {
                void __iomem *enable_reg = base;
                u32 enable_bit = name[3] - '0';

                parent_name = "main";
                switch (enable_bit) {
                case 0:
                        enable_reg += CPG_PLL0CR;
                        break;
                case 1:
                        enable_reg += CPG_PLL1CR;
                        break;
                case 2:
                        enable_reg += CPG_PLL2CR;
                        break;
                case 3:
                        enable_reg += CPG_PLL3CR;
                        break;
                default:
                        return ERR_PTR(-EINVAL);
                }
                if (readl(base + CPG_PLLECR) & BIT(enable_bit)) {
                        mult = ((readl(enable_reg) >> 24) & 0x3f) + 1;
                        /* handle CFG bit for PLL1 and PLL2 */
                        if (enable_bit == 1 || enable_bit == 2)
                                if (readl(enable_reg) & BIT(20))
                                        mult *= 2;
                }
        } else if (!strcmp(name, "dsi0phy") || !strcmp(name, "dsi1phy")) {
                u32 phy_no = name[3] - '0';
                void __iomem *dsi_reg = base +
                        (phy_no ? CPG_DSI1PHYCR : CPG_DSI0PHYCR);

                parent_name = phy_no ? "dsi1pck" : "dsi0pck";
                mult = readl(dsi_reg);
                if (!(mult & 0x8000))
                        mult = 1;
                else
                        mult = (mult & 0x3f) + 1;
        } else if (!strcmp(name, "z")) {
                parent_name = "pll0";
                table = z_div_table;
                reg = CPG_FRQCRB;
                shift = 24;
                width = 5;
        } else {
                const struct div4_clk *c;

                for (c = div4_clks; c->name; c++) {
                        if (!strcmp(name, c->name)) {
                                parent_name = c->parent;
                                table = div4_div_table;
                                reg = c->reg;
                                shift = c->shift;
                                width = 4;
                                break;
                        }
                }
                if (!c->name)
                        return ERR_PTR(-EINVAL);
        }

        if (!table) {
                return clk_register_fixed_factor(NULL, name, parent_name, 0,
                                                 mult, div);
        } else {
                return clk_register_divider_table(NULL, name, parent_name, 0,
                                                  base + reg, shift, width, 0,
                                                  table, &cpg->lock);
        }
}

static void __init sh73a0_cpg_clocks_init(struct device_node *np)
{
        struct sh73a0_cpg *cpg;
        void __iomem *base;
        struct clk **clks;
        unsigned int i;
        int num_clks;

        num_clks = of_property_count_strings(np, "clock-output-names");
        if (num_clks < 0) {
                pr_err("%s: failed to count clocks\n", __func__);
                return;
        }

        cpg = kzalloc_obj(*cpg);
        clks = kzalloc_objs(*clks, num_clks);
        if (cpg == NULL || clks == NULL) {
                /* We're leaking memory on purpose, there's no point in cleaning
                 * up as the system won't boot anyway.
                 */
                return;
        }

        spin_lock_init(&cpg->lock);

        cpg->data.clks = clks;
        cpg->data.clk_num = num_clks;

        base = of_iomap(np, 0);
        if (WARN_ON(base == NULL))
                return;

        /* Set SDHI clocks to a known state */
        writel(0x108, base + CPG_SD0CKCR);
        writel(0x108, base + CPG_SD1CKCR);
        writel(0x108, base + CPG_SD2CKCR);

        for (i = 0; i < num_clks; ++i) {
                const char *name;
                struct clk *clk;

                of_property_read_string_index(np, "clock-output-names", i,
                                              &name);

                clk = sh73a0_cpg_register_clock(np, cpg, base, name);
                if (IS_ERR(clk))
                        pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
                               __func__, np, name, PTR_ERR(clk));
                else
                        cpg->data.clks[i] = clk;
        }

        of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
}
CLK_OF_DECLARE(sh73a0_cpg_clks, "renesas,sh73a0-cpg-clocks",
               sh73a0_cpg_clocks_init);