linux/drivers/clk/microchip/clk-pic32mzda.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Purna Chandra Mandal,<purna.mandal@microchip.com>
   4 * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
   5 */
   6#include <dt-bindings/clock/microchip,pic32-clock.h>
   7#include <linux/clk.h>
   8#include <linux/clk-provider.h>
   9#include <linux/clkdev.h>
  10#include <linux/io.h>
  11#include <linux/module.h>
  12#include <linux/of_address.h>
  13#include <linux/of_platform.h>
  14#include <linux/platform_device.h>
  15#include <asm/traps.h>
  16
  17#include "clk-core.h"
  18
  19/* FRC Postscaler */
  20#define OSC_FRCDIV_MASK         0x07
  21#define OSC_FRCDIV_SHIFT        24
  22
  23/* SPLL fields */
  24#define PLL_ICLK_MASK           0x01
  25#define PLL_ICLK_SHIFT          7
  26
  27#define DECLARE_PERIPHERAL_CLOCK(__clk_name, __reg, __flags)    \
  28        {                                                       \
  29                .ctrl_reg = (__reg),                            \
  30                .init_data = {                                  \
  31                        .name = (__clk_name),                   \
  32                        .parent_names = (const char *[]) {      \
  33                                "sys_clk"                       \
  34                        },                                      \
  35                        .num_parents = 1,                       \
  36                        .ops = &pic32_pbclk_ops,                \
  37                        .flags = (__flags),                     \
  38                },                                              \
  39        }
  40
  41#define DECLARE_REFO_CLOCK(__clkid, __reg)                              \
  42        {                                                               \
  43                .ctrl_reg = (__reg),                                    \
  44                .init_data = {                                          \
  45                        .name = "refo" #__clkid "_clk",                 \
  46                        .parent_names = (const char *[]) {              \
  47                                "sys_clk", "pb1_clk", "posc_clk",       \
  48                                "frc_clk", "lprc_clk", "sosc_clk",      \
  49                                "sys_pll", "refi" #__clkid "_clk",      \
  50                                "bfrc_clk",                             \
  51                        },                                              \
  52                        .num_parents = 9,                               \
  53                        .flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE,\
  54                        .ops = &pic32_roclk_ops,                        \
  55                },                                                      \
  56                .parent_map = (const u32[]) {                           \
  57                        0, 1, 2, 3, 4, 5, 7, 8, 9                       \
  58                },                                                      \
  59        }
  60
  61static const struct pic32_ref_osc_data ref_clks[] = {
  62        DECLARE_REFO_CLOCK(1, 0x80),
  63        DECLARE_REFO_CLOCK(2, 0xa0),
  64        DECLARE_REFO_CLOCK(3, 0xc0),
  65        DECLARE_REFO_CLOCK(4, 0xe0),
  66        DECLARE_REFO_CLOCK(5, 0x100),
  67};
  68
  69static const struct pic32_periph_clk_data periph_clocks[] = {
  70        DECLARE_PERIPHERAL_CLOCK("pb1_clk", 0x140, 0),
  71        DECLARE_PERIPHERAL_CLOCK("pb2_clk", 0x150, CLK_IGNORE_UNUSED),
  72        DECLARE_PERIPHERAL_CLOCK("pb3_clk", 0x160, 0),
  73        DECLARE_PERIPHERAL_CLOCK("pb4_clk", 0x170, 0),
  74        DECLARE_PERIPHERAL_CLOCK("pb5_clk", 0x180, 0),
  75        DECLARE_PERIPHERAL_CLOCK("pb6_clk", 0x190, 0),
  76        DECLARE_PERIPHERAL_CLOCK("cpu_clk", 0x1a0, CLK_IGNORE_UNUSED),
  77};
  78
  79static const struct pic32_sys_clk_data sys_mux_clk = {
  80        .slew_reg = 0x1c0,
  81        .slew_div = 2, /* step of div_4 -> div_2 -> no_div */
  82        .init_data = {
  83                .name = "sys_clk",
  84                .parent_names = (const char *[]) {
  85                        "frcdiv_clk", "sys_pll", "posc_clk",
  86                        "sosc_clk", "lprc_clk", "frcdiv_clk",
  87                },
  88                .num_parents = 6,
  89                .ops = &pic32_sclk_ops,
  90        },
  91        .parent_map = (const u32[]) {
  92                0, 1, 2, 4, 5, 7,
  93        },
  94};
  95
  96static const struct pic32_sys_pll_data sys_pll = {
  97        .ctrl_reg = 0x020,
  98        .status_reg = 0x1d0,
  99        .lock_mask = BIT(7),
 100        .init_data = {
 101                .name = "sys_pll",
 102                .parent_names = (const char *[]) {
 103                        "spll_mux_clk"
 104                },
 105                .num_parents = 1,
 106                .ops = &pic32_spll_ops,
 107        },
 108};
 109
 110static const struct pic32_sec_osc_data sosc_clk = {
 111        .status_reg = 0x1d0,
 112        .enable_mask = BIT(1),
 113        .status_mask = BIT(4),
 114        .fixed_rate = 32768,
 115        .init_data = {
 116                .name = "sosc_clk",
 117                .parent_names = NULL,
 118                .ops = &pic32_sosc_ops,
 119        },
 120};
 121
 122static int pic32mzda_critical_clks[] = {
 123        PB2CLK, PB7CLK
 124};
 125
 126/* PIC32MZDA clock data */
 127struct pic32mzda_clk_data {
 128        struct clk *clks[MAXCLKS];
 129        struct pic32_clk_common core;
 130        struct clk_onecell_data onecell_data;
 131        struct notifier_block failsafe_notifier;
 132};
 133
 134static int pic32_fscm_nmi(struct notifier_block *nb,
 135                          unsigned long action, void *data)
 136{
 137        struct pic32mzda_clk_data *cd;
 138
 139        cd  = container_of(nb, struct pic32mzda_clk_data, failsafe_notifier);
 140
 141        /* SYSCLK is now running from BFRCCLK. Report clock failure. */
 142        if (readl(cd->core.iobase) & BIT(2))
 143                pr_alert("pic32-clk: FSCM detected clk failure.\n");
 144
 145        /* TODO: detect reason of failure and recover accordingly */
 146
 147        return NOTIFY_OK;
 148}
 149
 150static int pic32mzda_clk_probe(struct platform_device *pdev)
 151{
 152        const char *const pll_mux_parents[] = {"posc_clk", "frc_clk"};
 153        struct device_node *np = pdev->dev.of_node;
 154        struct pic32mzda_clk_data *cd;
 155        struct pic32_clk_common *core;
 156        struct clk *pll_mux_clk, *clk;
 157        struct clk **clks;
 158        int nr_clks, i, ret;
 159
 160        cd = devm_kzalloc(&pdev->dev, sizeof(*cd), GFP_KERNEL);
 161        if (!cd)
 162                return -ENOMEM;
 163
 164        core = &cd->core;
 165        core->iobase = of_io_request_and_map(np, 0, of_node_full_name(np));
 166        if (IS_ERR(core->iobase)) {
 167                dev_err(&pdev->dev, "pic32-clk: failed to map registers\n");
 168                return PTR_ERR(core->iobase);
 169        }
 170
 171        spin_lock_init(&core->reg_lock);
 172        core->dev = &pdev->dev;
 173        clks = &cd->clks[0];
 174
 175        /* register fixed rate clocks */
 176        clks[POSCCLK] = clk_register_fixed_rate(&pdev->dev, "posc_clk", NULL,
 177                                                0, 24000000);
 178        clks[FRCCLK] =  clk_register_fixed_rate(&pdev->dev, "frc_clk", NULL,
 179                                                0, 8000000);
 180        clks[BFRCCLK] = clk_register_fixed_rate(&pdev->dev, "bfrc_clk", NULL,
 181                                                0, 8000000);
 182        clks[LPRCCLK] = clk_register_fixed_rate(&pdev->dev, "lprc_clk", NULL,
 183                                                0, 32000);
 184        clks[UPLLCLK] = clk_register_fixed_rate(&pdev->dev, "usbphy_clk", NULL,
 185                                                0, 24000000);
 186        /* fixed rate (optional) clock */
 187        if (of_find_property(np, "microchip,pic32mzda-sosc", NULL)) {
 188                pr_info("pic32-clk: dt requests SOSC.\n");
 189                clks[SOSCCLK] = pic32_sosc_clk_register(&sosc_clk, core);
 190        }
 191        /* divider clock */
 192        clks[FRCDIVCLK] = clk_register_divider(&pdev->dev, "frcdiv_clk",
 193                                               "frc_clk", 0,
 194                                               core->iobase,
 195                                               OSC_FRCDIV_SHIFT,
 196                                               OSC_FRCDIV_MASK,
 197                                               CLK_DIVIDER_POWER_OF_TWO,
 198                                               &core->reg_lock);
 199        /* PLL ICLK mux */
 200        pll_mux_clk = clk_register_mux(&pdev->dev, "spll_mux_clk",
 201                                       pll_mux_parents, 2, 0,
 202                                       core->iobase + 0x020,
 203                                       PLL_ICLK_SHIFT, 1, 0, &core->reg_lock);
 204        if (IS_ERR(pll_mux_clk))
 205                pr_err("spll_mux_clk: clk register failed\n");
 206
 207        /* PLL */
 208        clks[PLLCLK] = pic32_spll_clk_register(&sys_pll, core);
 209        /* SYSTEM clock */
 210        clks[SCLK] = pic32_sys_clk_register(&sys_mux_clk, core);
 211        /* Peripheral bus clocks */
 212        for (nr_clks = PB1CLK, i = 0; nr_clks <= PB7CLK; i++, nr_clks++)
 213                clks[nr_clks] = pic32_periph_clk_register(&periph_clocks[i],
 214                                                          core);
 215        /* Reference oscillator clock */
 216        for (nr_clks = REF1CLK, i = 0; nr_clks <= REF5CLK; i++, nr_clks++)
 217                clks[nr_clks] = pic32_refo_clk_register(&ref_clks[i], core);
 218
 219        /* register clkdev */
 220        for (i = 0; i < MAXCLKS; i++) {
 221                if (IS_ERR(clks[i]))
 222                        continue;
 223                clk_register_clkdev(clks[i], NULL, __clk_get_name(clks[i]));
 224        }
 225
 226        /* register clock provider */
 227        cd->onecell_data.clks = clks;
 228        cd->onecell_data.clk_num = MAXCLKS;
 229        ret = of_clk_add_provider(np, of_clk_src_onecell_get,
 230                                  &cd->onecell_data);
 231        if (ret)
 232                return ret;
 233
 234        /* force enable critical clocks */
 235        for (i = 0; i < ARRAY_SIZE(pic32mzda_critical_clks); i++) {
 236                clk = clks[pic32mzda_critical_clks[i]];
 237                if (clk_prepare_enable(clk))
 238                        dev_err(&pdev->dev, "clk_prepare_enable(%s) failed\n",
 239                                __clk_get_name(clk));
 240        }
 241
 242        /* register NMI for failsafe clock monitor */
 243        cd->failsafe_notifier.notifier_call = pic32_fscm_nmi;
 244        return register_nmi_notifier(&cd->failsafe_notifier);
 245}
 246
 247static const struct of_device_id pic32mzda_clk_match_table[] = {
 248        { .compatible = "microchip,pic32mzda-clk", },
 249        { }
 250};
 251MODULE_DEVICE_TABLE(of, pic32mzda_clk_match_table);
 252
 253static struct platform_driver pic32mzda_clk_driver = {
 254        .probe          = pic32mzda_clk_probe,
 255        .driver         = {
 256                .name   = "clk-pic32mzda",
 257                .of_match_table = pic32mzda_clk_match_table,
 258        },
 259};
 260
 261static int __init microchip_pic32mzda_clk_init(void)
 262{
 263        return platform_driver_register(&pic32mzda_clk_driver);
 264}
 265core_initcall(microchip_pic32mzda_clk_init);
 266
 267MODULE_DESCRIPTION("Microchip PIC32MZDA Clock Driver");
 268MODULE_LICENSE("GPL v2");
 269MODULE_ALIAS("platform:clk-pic32mzda");
 270