LXR linux/drivers/clk/samsung/clk-s3c2412.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
   4 *
   5 * Common Clock Framework support for S3C2412 and S3C2413.
   6 */
   7
   8#include <linux/clk-provider.h>
   9#include <linux/clk/samsung.h>
  10#include <linux/io.h>
  11#include <linux/of.h>
  12#include <linux/of_address.h>
  13#include <linux/reboot.h>
  14
  15#include <dt-bindings/clock/s3c2412.h>
  16
  17#include "clk.h"
  18#include "clk-pll.h"
  19
  20#define LOCKTIME        0x00
  21#define MPLLCON         0x04
  22#define UPLLCON         0x08
  23#define CLKCON          0x0c
  24#define CLKDIVN         0x14
  25#define CLKSRC          0x1c
  26#define SWRST           0x30
  27
  28static void __iomem *reg_base;
  29
  30/*
  31 * list of controller registers to be saved and restored during a
  32 * suspend/resume cycle.
  33 */
  34static unsigned long s3c2412_clk_regs[] __initdata = {
  35        LOCKTIME,
  36        MPLLCON,
  37        UPLLCON,
  38        CLKCON,
  39        CLKDIVN,
  40        CLKSRC,
  41};
  42
  43static struct clk_div_table divxti_d[] = {
  44        { .val = 0, .div = 1 },
  45        { .val = 1, .div = 2 },
  46        { .val = 2, .div = 4 },
  47        { .val = 3, .div = 6 },
  48        { .val = 4, .div = 8 },
  49        { .val = 5, .div = 10 },
  50        { .val = 6, .div = 12 },
  51        { .val = 7, .div = 14 },
  52        { /* sentinel */ },
  53};
  54
  55static struct samsung_div_clock s3c2412_dividers[] __initdata = {
  56        DIV_T(0, "div_xti", "xti", CLKSRC, 0, 3, divxti_d),
  57        DIV(0, "div_cam", "mux_cam", CLKDIVN, 16, 4),
  58        DIV(0, "div_i2s", "mux_i2s", CLKDIVN, 12, 4),
  59        DIV(0, "div_uart", "mux_uart", CLKDIVN, 8, 4),
  60        DIV(0, "div_usb", "mux_usb", CLKDIVN, 6, 1),
  61        DIV(0, "div_hclk_half", "hclk", CLKDIVN, 5, 1),
  62        DIV(ARMDIV, "armdiv", "msysclk", CLKDIVN, 3, 1),
  63        DIV(PCLK, "pclk", "hclk", CLKDIVN, 2, 1),
  64        DIV(HCLK, "hclk", "armdiv", CLKDIVN, 0, 2),
  65};
  66
  67static struct samsung_fixed_factor_clock s3c2412_ffactor[] __initdata = {
  68        FFACTOR(0, "ff_hclk", "hclk", 2, 1, CLK_SET_RATE_PARENT),
  69};
  70
  71/*
  72 * The first two use the OM[4] setting, which is not readable from
  73 * software, so assume it is set to xti.
  74 */
  75PNAME(erefclk_p) = { "xti", "xti", "xti", "ext" };
  76PNAME(urefclk_p) = { "xti", "xti", "xti", "ext" };
  77
  78PNAME(camclk_p) = { "usysclk", "hclk" };
  79PNAME(usbclk_p) = { "usysclk", "hclk" };
  80PNAME(i2sclk_p) = { "erefclk", "mpll" };
  81PNAME(uartclk_p) = { "erefclk", "mpll" };
  82PNAME(usysclk_p) = { "urefclk", "upll" };
  83PNAME(msysclk_p) = { "mdivclk", "mpll" };
  84PNAME(mdivclk_p) = { "xti", "div_xti" };
  85PNAME(armclk_p) = { "armdiv", "hclk" };
  86
  87static struct samsung_mux_clock s3c2412_muxes[] __initdata = {
  88        MUX(0, "erefclk", erefclk_p, CLKSRC, 14, 2),
  89        MUX(0, "urefclk", urefclk_p, CLKSRC, 12, 2),
  90        MUX(0, "mux_cam", camclk_p, CLKSRC, 11, 1),
  91        MUX(0, "mux_usb", usbclk_p, CLKSRC, 10, 1),
  92        MUX(0, "mux_i2s", i2sclk_p, CLKSRC, 9, 1),
  93        MUX(0, "mux_uart", uartclk_p, CLKSRC, 8, 1),
  94        MUX(USYSCLK, "usysclk", usysclk_p, CLKSRC, 5, 1),
  95        MUX(MSYSCLK, "msysclk", msysclk_p, CLKSRC, 4, 1),
  96        MUX(MDIVCLK, "mdivclk", mdivclk_p, CLKSRC, 3, 1),
  97        MUX(ARMCLK, "armclk", armclk_p, CLKDIVN, 4, 1),
  98};
  99
 100static struct samsung_pll_clock s3c2412_plls[] __initdata = {
 101        PLL(pll_s3c2440_mpll, MPLL, "mpll", "xti", LOCKTIME, MPLLCON, NULL),
 102        PLL(pll_s3c2410_upll, UPLL, "upll", "urefclk", LOCKTIME, UPLLCON, NULL),
 103};
 104
 105static struct samsung_gate_clock s3c2412_gates[] __initdata = {
 106        GATE(PCLK_WDT, "wdt", "pclk", CLKCON, 28, 0, 0),
 107        GATE(PCLK_SPI, "spi", "pclk", CLKCON, 27, 0, 0),
 108        GATE(PCLK_I2S, "i2s", "pclk", CLKCON, 26, 0, 0),
 109        GATE(PCLK_I2C, "i2c", "pclk", CLKCON, 25, 0, 0),
 110        GATE(PCLK_ADC, "adc", "pclk", CLKCON, 24, 0, 0),
 111        GATE(PCLK_RTC, "rtc", "pclk", CLKCON, 23, 0, 0),
 112        GATE(PCLK_GPIO, "gpio", "pclk", CLKCON, 22, CLK_IGNORE_UNUSED, 0),
 113        GATE(PCLK_UART2, "uart2", "pclk", CLKCON, 21, 0, 0),
 114        GATE(PCLK_UART1, "uart1", "pclk", CLKCON, 20, 0, 0),
 115        GATE(PCLK_UART0, "uart0", "pclk", CLKCON, 19, 0, 0),
 116        GATE(PCLK_SDI, "sdi", "pclk", CLKCON, 18, 0, 0),
 117        GATE(PCLK_PWM, "pwm", "pclk", CLKCON, 17, 0, 0),
 118        GATE(PCLK_USBD, "usb-device", "pclk", CLKCON, 16, 0, 0),
 119        GATE(SCLK_CAM, "sclk_cam", "div_cam", CLKCON, 15, 0, 0),
 120        GATE(SCLK_UART, "sclk_uart", "div_uart", CLKCON, 14, 0, 0),
 121        GATE(SCLK_I2S, "sclk_i2s", "div_i2s", CLKCON, 13, 0, 0),
 122        GATE(SCLK_USBH, "sclk_usbh", "div_usb", CLKCON, 12, 0, 0),
 123        GATE(SCLK_USBD, "sclk_usbd", "div_usb", CLKCON, 11, 0, 0),
 124        GATE(HCLK_HALF, "hclk_half", "div_hclk_half", CLKCON, 10, CLK_IGNORE_UNUSED, 0),
 125        GATE(HCLK_X2, "hclkx2", "ff_hclk", CLKCON, 9, CLK_IGNORE_UNUSED, 0),
 126        GATE(HCLK_SDRAM, "sdram", "hclk", CLKCON, 8, CLK_IGNORE_UNUSED, 0),
 127        GATE(HCLK_USBH, "usb-host", "hclk", CLKCON, 6, 0, 0),
 128        GATE(HCLK_LCD, "lcd", "hclk", CLKCON, 5, 0, 0),
 129        GATE(HCLK_NAND, "nand", "hclk", CLKCON, 4, 0, 0),
 130        GATE(HCLK_DMA3, "dma3", "hclk", CLKCON, 3, CLK_IGNORE_UNUSED, 0),
 131        GATE(HCLK_DMA2, "dma2", "hclk", CLKCON, 2, CLK_IGNORE_UNUSED, 0),
 132        GATE(HCLK_DMA1, "dma1", "hclk", CLKCON, 1, CLK_IGNORE_UNUSED, 0),
 133        GATE(HCLK_DMA0, "dma0", "hclk", CLKCON, 0, CLK_IGNORE_UNUSED, 0),
 134};
 135
 136static struct samsung_clock_alias s3c2412_aliases[] __initdata = {
 137        ALIAS(PCLK_UART0, "s3c2412-uart.0", "uart"),
 138        ALIAS(PCLK_UART1, "s3c2412-uart.1", "uart"),
 139        ALIAS(PCLK_UART2, "s3c2412-uart.2", "uart"),
 140        ALIAS(PCLK_UART0, "s3c2412-uart.0", "clk_uart_baud2"),
 141        ALIAS(PCLK_UART1, "s3c2412-uart.1", "clk_uart_baud2"),
 142        ALIAS(PCLK_UART2, "s3c2412-uart.2", "clk_uart_baud2"),
 143        ALIAS(SCLK_UART, NULL, "clk_uart_baud3"),
 144        ALIAS(PCLK_I2C, "s3c2410-i2c.0", "i2c"),
 145        ALIAS(PCLK_ADC, NULL, "adc"),
 146        ALIAS(PCLK_RTC, NULL, "rtc"),
 147        ALIAS(PCLK_PWM, NULL, "timers"),
 148        ALIAS(HCLK_LCD, NULL, "lcd"),
 149        ALIAS(PCLK_USBD, NULL, "usb-device"),
 150        ALIAS(SCLK_USBD, NULL, "usb-bus-gadget"),
 151        ALIAS(HCLK_USBH, NULL, "usb-host"),
 152        ALIAS(SCLK_USBH, NULL, "usb-bus-host"),
 153        ALIAS(ARMCLK, NULL, "armclk"),
 154        ALIAS(HCLK, NULL, "hclk"),
 155        ALIAS(MPLL, NULL, "mpll"),
 156        ALIAS(MSYSCLK, NULL, "fclk"),
 157};
 158
 159static int s3c2412_restart(struct notifier_block *this,
 160                           unsigned long mode, void *cmd)
 161{
 162        /* errata "Watch-dog/Software Reset Problem" specifies that
 163         * this reset must be done with the SYSCLK sourced from
 164         * EXTCLK instead of FOUT to avoid a glitch in the reset
 165         * mechanism.
 166         *
 167         * See the watchdog section of the S3C2412 manual for more
 168         * information on this fix.
 169         */
 170
 171        __raw_writel(0x00, reg_base + CLKSRC);
 172        __raw_writel(0x533C2412, reg_base + SWRST);
 173        return NOTIFY_DONE;
 174}
 175
 176static struct notifier_block s3c2412_restart_handler = {
 177        .notifier_call = s3c2412_restart,
 178        .priority = 129,
 179};
 180
 181/*
 182 * fixed rate clocks generated outside the soc
 183 * Only necessary until the devicetree-move is complete
 184 */
 185#define XTI     1
 186static struct samsung_fixed_rate_clock s3c2412_common_frate_clks[] __initdata = {
 187        FRATE(XTI, "xti", NULL, 0, 0),
 188        FRATE(0, "ext", NULL, 0, 0),
 189};
 190
 191static void __init s3c2412_common_clk_register_fixed_ext(
 192                struct samsung_clk_provider *ctx,
 193                unsigned long xti_f, unsigned long ext_f)
 194{
 195        /* xtal alias is necessary for the current cpufreq driver */
 196        struct samsung_clock_alias xti_alias = ALIAS(XTI, NULL, "xtal");
 197
 198        s3c2412_common_frate_clks[0].fixed_rate = xti_f;
 199        s3c2412_common_frate_clks[1].fixed_rate = ext_f;
 200        samsung_clk_register_fixed_rate(ctx, s3c2412_common_frate_clks,
 201                                ARRAY_SIZE(s3c2412_common_frate_clks));
 202
 203        samsung_clk_register_alias(ctx, &xti_alias, 1);
 204}
 205
 206void __init s3c2412_common_clk_init(struct device_node *np, unsigned long xti_f,
 207                                    unsigned long ext_f, void __iomem *base)
 208{
 209        struct samsung_clk_provider *ctx;
 210        int ret;
 211        reg_base = base;
 212
 213        if (np) {
 214                reg_base = of_iomap(np, 0);
 215                if (!reg_base)
 216                        panic("%s: failed to map registers\n", __func__);
 217        }
 218
 219        ctx = samsung_clk_init(np, reg_base, NR_CLKS);
 220
 221        /* Register external clocks only in non-dt cases */
 222        if (!np)
 223                s3c2412_common_clk_register_fixed_ext(ctx, xti_f, ext_f);
 224
 225        /* Register PLLs. */
 226        samsung_clk_register_pll(ctx, s3c2412_plls, ARRAY_SIZE(s3c2412_plls),
 227                                 reg_base);
 228
 229        /* Register common internal clocks. */
 230        samsung_clk_register_mux(ctx, s3c2412_muxes, ARRAY_SIZE(s3c2412_muxes));
 231        samsung_clk_register_div(ctx, s3c2412_dividers,
 232                                          ARRAY_SIZE(s3c2412_dividers));
 233        samsung_clk_register_gate(ctx, s3c2412_gates,
 234                                        ARRAY_SIZE(s3c2412_gates));
 235        samsung_clk_register_fixed_factor(ctx, s3c2412_ffactor,
 236                                          ARRAY_SIZE(s3c2412_ffactor));
 237        samsung_clk_register_alias(ctx, s3c2412_aliases,
 238                                   ARRAY_SIZE(s3c2412_aliases));
 239
 240        samsung_clk_sleep_init(reg_base, s3c2412_clk_regs,
 241                               ARRAY_SIZE(s3c2412_clk_regs));
 242
 243        samsung_clk_of_add_provider(np, ctx);
 244
 245        ret = register_restart_handler(&s3c2412_restart_handler);
 246        if (ret)
 247                pr_warn("cannot register restart handler, %d\n", ret);
 248}
 249
 250static void __init s3c2412_clk_init(struct device_node *np)
 251{
 252        s3c2412_common_clk_init(np, 0, 0, NULL);
 253}
 254CLK_OF_DECLARE(s3c2412_clk, "samsung,s3c2412-clock", s3c2412_clk_init);
 255