drivers/clk/samsung/clk-s3c2412.c

   1 /*
   2  * Copyright (c) 2013 Heiko Stuebner <heiko@sntech.de>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Common Clock Framework support for S3C2412 and S3C2413.
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/of.h>
  13 #include <linux/of_address.h>
  14 #include <linux/syscore_ops.h>
  15 #include <linux/reboot.h>
  16
  17 #include <dt-bindings/clock/s3c2412.h>
  18
  19 #include "clk.h"
  20 #include "clk-pll.h"
  21
  22 #define LOCKTIME        0x00
  23 #define MPLLCON         0x04
  24 #define UPLLCON         0x08
  25 #define CLKCON          0x0c
  26 #define CLKDIVN         0x14
  27 #define CLKSRC          0x1c
  28 #define SWRST           0x30
  29
  30 /* list of PLLs to be registered */
  31 enum s3c2412_plls {
  32         mpll, upll,
  33 };
  34
  35 static void __iomem *reg_base;
  36
  37 #ifdef CONFIG_PM_SLEEP
  38 static struct samsung_clk_reg_dump *s3c2412_save;
  39
  40 /*
  41  * list of controller registers to be saved and restored during a
  42  * suspend/resume cycle.
  43  */
  44 static unsigned long s3c2412_clk_regs[] __initdata = {
  45         LOCKTIME,
  46         MPLLCON,
  47         UPLLCON,
  48         CLKCON,
  49         CLKDIVN,
  50         CLKSRC,
  51 };
  52
  53 static int s3c2412_clk_suspend(void)
  54 {
  55         samsung_clk_save(reg_base, s3c2412_save,
  56                                 ARRAY_SIZE(s3c2412_clk_regs));
  57
  58         return 0;
  59 }
  60
  61 static void s3c2412_clk_resume(void)
  62 {
  63         samsung_clk_restore(reg_base, s3c2412_save,
  64                                 ARRAY_SIZE(s3c2412_clk_regs));
  65 }
  66
  67 static struct syscore_ops s3c2412_clk_syscore_ops = {
  68         .suspend = s3c2412_clk_suspend,
  69         .resume = s3c2412_clk_resume,
  70 };
  71
  72 static void s3c2412_clk_sleep_init(void)
  73 {
  74         s3c2412_save = samsung_clk_alloc_reg_dump(s3c2412_clk_regs,
  75                                                 ARRAY_SIZE(s3c2412_clk_regs));
  76         if (!s3c2412_save) {
  77                 pr_warn("%s: failed to allocate sleep save data, no sleep support!\n",
  78                         __func__);
  79                 return;
  80         }
  81
  82         register_syscore_ops(&s3c2412_clk_syscore_ops);
  83         return;
  84 }
  85 #else
  86 static void s3c2412_clk_sleep_init(void) {}
  87 #endif
  88
  89 static struct clk_div_table divxti_d[] = {
  90         { .val = 0, .div = 1 },
  91         { .val = 1, .div = 2 },
  92         { .val = 2, .div = 4 },
  93         { .val = 3, .div = 6 },
  94         { .val = 4, .div = 8 },
  95         { .val = 5, .div = 10 },
  96         { .val = 6, .div = 12 },
  97         { .val = 7, .div = 14 },
  98         { /* sentinel */ },
  99 };
 100
 101 struct samsung_div_clock s3c2412_dividers[] __initdata = {
 102         DIV_T(0, "div_xti", "xti", CLKSRC, 0, 3, divxti_d),
 103         DIV(0, "div_cam", "mux_cam", CLKDIVN, 16, 4),
 104         DIV(0, "div_i2s", "mux_i2s", CLKDIVN, 12, 4),
 105         DIV(0, "div_uart", "mux_uart", CLKDIVN, 8, 4),
 106         DIV(0, "div_usb", "mux_usb", CLKDIVN, 6, 1),
 107         DIV(0, "div_hclk_half", "hclk", CLKDIVN, 5, 1),
 108         DIV(ARMDIV, "armdiv", "msysclk", CLKDIVN, 3, 1),
 109         DIV(PCLK, "pclk", "hclk", CLKDIVN, 2, 1),
 110         DIV(HCLK, "hclk", "armdiv", CLKDIVN, 0, 2),
 111 };
 112
 113 struct samsung_fixed_factor_clock s3c2412_ffactor[] __initdata = {
 114         FFACTOR(0, "ff_hclk", "hclk", 2, 1, CLK_SET_RATE_PARENT),
 115 };
 116
 117 /*
 118  * The first two use the OM[4] setting, which is not readable from
 119  * software, so assume it is set to xti.
 120  */
 121 PNAME(erefclk_p) = { "xti", "xti", "xti", "ext" };
 122 PNAME(urefclk_p) = { "xti", "xti", "xti", "ext" };
 123
 124 PNAME(camclk_p) = { "usysclk", "hclk" };
 125 PNAME(usbclk_p) = { "usysclk", "hclk" };
 126 PNAME(i2sclk_p) = { "erefclk", "mpll" };
 127 PNAME(uartclk_p) = { "erefclk", "mpll" };
 128 PNAME(usysclk_p) = { "urefclk", "upll" };
 129 PNAME(msysclk_p) = { "mdivclk", "mpll" };
 130 PNAME(mdivclk_p) = { "xti", "div_xti" };
 131 PNAME(armclk_p) = { "armdiv", "hclk" };
 132
 133 struct samsung_mux_clock s3c2412_muxes[] __initdata = {
 134         MUX(0, "erefclk", erefclk_p, CLKSRC, 14, 2),
 135         MUX(0, "urefclk", urefclk_p, CLKSRC, 12, 2),
 136         MUX(0, "mux_cam", camclk_p, CLKSRC, 11, 1),
 137         MUX(0, "mux_usb", usbclk_p, CLKSRC, 10, 1),
 138         MUX(0, "mux_i2s", i2sclk_p, CLKSRC, 9, 1),
 139         MUX(0, "mux_uart", uartclk_p, CLKSRC, 8, 1),
 140         MUX(USYSCLK, "usysclk", usysclk_p, CLKSRC, 5, 1),
 141         MUX(MSYSCLK, "msysclk", msysclk_p, CLKSRC, 4, 1),
 142         MUX(MDIVCLK, "mdivclk", mdivclk_p, CLKSRC, 3, 1),
 143         MUX(ARMCLK, "armclk", armclk_p, CLKDIVN, 4, 1),
 144 };
 145
 146 static struct samsung_pll_clock s3c2412_plls[] __initdata = {
 147         [mpll] = PLL(pll_s3c2440_mpll, MPLL, "mpll", "xti",
 148                                                 LOCKTIME, MPLLCON, NULL),
 149         [upll] = PLL(pll_s3c2410_upll, UPLL, "upll", "urefclk",
 150                                                 LOCKTIME, UPLLCON, NULL),
 151 };
 152
 153 struct samsung_gate_clock s3c2412_gates[] __initdata = {
 154         GATE(PCLK_WDT, "wdt", "pclk", CLKCON, 28, 0, 0),
 155         GATE(PCLK_SPI, "spi", "pclk", CLKCON, 27, 0, 0),
 156         GATE(PCLK_I2S, "i2s", "pclk", CLKCON, 26, 0, 0),
 157         GATE(PCLK_I2C, "i2c", "pclk", CLKCON, 25, 0, 0),
 158         GATE(PCLK_ADC, "adc", "pclk", CLKCON, 24, 0, 0),
 159         GATE(PCLK_RTC, "rtc", "pclk", CLKCON, 23, 0, 0),
 160         GATE(PCLK_GPIO, "gpio", "pclk", CLKCON, 22, CLK_IGNORE_UNUSED, 0),
 161         GATE(PCLK_UART2, "uart2", "pclk", CLKCON, 21, 0, 0),
 162         GATE(PCLK_UART1, "uart1", "pclk", CLKCON, 20, 0, 0),
 163         GATE(PCLK_UART0, "uart0", "pclk", CLKCON, 19, 0, 0),
 164         GATE(PCLK_SDI, "sdi", "pclk", CLKCON, 18, 0, 0),
 165         GATE(PCLK_PWM, "pwm", "pclk", CLKCON, 17, 0, 0),
 166         GATE(PCLK_USBD, "usb-device", "pclk", CLKCON, 16, 0, 0),
 167         GATE(SCLK_CAM, "sclk_cam", "div_cam", CLKCON, 15, 0, 0),
 168         GATE(SCLK_UART, "sclk_uart", "div_uart", CLKCON, 14, 0, 0),
 169         GATE(SCLK_I2S, "sclk_i2s", "div_i2s", CLKCON, 13, 0, 0),
 170         GATE(SCLK_USBH, "sclk_usbh", "div_usb", CLKCON, 12, 0, 0),
 171         GATE(SCLK_USBD, "sclk_usbd", "div_usb", CLKCON, 11, 0, 0),
 172         GATE(HCLK_HALF, "hclk_half", "div_hclk_half", CLKCON, 10, CLK_IGNORE_UNUSED, 0),
 173         GATE(HCLK_X2, "hclkx2", "ff_hclk", CLKCON, 9, CLK_IGNORE_UNUSED, 0),
 174         GATE(HCLK_SDRAM, "sdram", "hclk", CLKCON, 8, CLK_IGNORE_UNUSED, 0),
 175         GATE(HCLK_USBH, "usb-host", "hclk", CLKCON, 6, 0, 0),
 176         GATE(HCLK_LCD, "lcd", "hclk", CLKCON, 5, 0, 0),
 177         GATE(HCLK_NAND, "nand", "hclk", CLKCON, 4, 0, 0),
 178         GATE(HCLK_DMA3, "dma3", "hclk", CLKCON, 3, CLK_IGNORE_UNUSED, 0),
 179         GATE(HCLK_DMA2, "dma2", "hclk", CLKCON, 2, CLK_IGNORE_UNUSED, 0),
 180         GATE(HCLK_DMA1, "dma1", "hclk", CLKCON, 1, CLK_IGNORE_UNUSED, 0),
 181         GATE(HCLK_DMA0, "dma0", "hclk", CLKCON, 0, CLK_IGNORE_UNUSED, 0),
 182 };
 183
 184 struct samsung_clock_alias s3c2412_aliases[] __initdata = {
 185         ALIAS(PCLK_UART0, "s3c2412-uart.0", "uart"),
 186         ALIAS(PCLK_UART1, "s3c2412-uart.1", "uart"),
 187         ALIAS(PCLK_UART2, "s3c2412-uart.2", "uart"),
 188         ALIAS(PCLK_UART0, "s3c2412-uart.0", "clk_uart_baud2"),
 189         ALIAS(PCLK_UART1, "s3c2412-uart.1", "clk_uart_baud2"),
 190         ALIAS(PCLK_UART2, "s3c2412-uart.2", "clk_uart_baud2"),
 191         ALIAS(SCLK_UART, NULL, "clk_uart_baud3"),
 192         ALIAS(PCLK_I2C, "s3c2410-i2c.0", "i2c"),
 193         ALIAS(PCLK_ADC, NULL, "adc"),
 194         ALIAS(PCLK_RTC, NULL, "rtc"),
 195         ALIAS(PCLK_PWM, NULL, "timers"),
 196         ALIAS(HCLK_LCD, NULL, "lcd"),
 197         ALIAS(PCLK_USBD, NULL, "usb-device"),
 198         ALIAS(SCLK_USBD, NULL, "usb-bus-gadget"),
 199         ALIAS(HCLK_USBH, NULL, "usb-host"),
 200         ALIAS(SCLK_USBH, NULL, "usb-bus-host"),
 201         ALIAS(ARMCLK, NULL, "armclk"),
 202         ALIAS(HCLK, NULL, "hclk"),
 203         ALIAS(MPLL, NULL, "mpll"),
 204         ALIAS(MSYSCLK, NULL, "fclk"),
 205 };
 206
 207 static int s3c2412_restart(struct notifier_block *this,
 208                            unsigned long mode, void *cmd)
 209 {
 210         /* errata "Watch-dog/Software Reset Problem" specifies that
 211          * this reset must be done with the SYSCLK sourced from
 212          * EXTCLK instead of FOUT to avoid a glitch in the reset
 213          * mechanism.
 214          *
 215          * See the watchdog section of the S3C2412 manual for more
 216          * information on this fix.
 217          */
 218
 219         __raw_writel(0x00, reg_base + CLKSRC);
 220         __raw_writel(0x533C2412, reg_base + SWRST);
 221         return NOTIFY_DONE;
 222 }
 223
 224 static struct notifier_block s3c2412_restart_handler = {
 225         .notifier_call = s3c2412_restart,
 226         .priority = 129,
 227 };
 228
 229 /*
 230  * fixed rate clocks generated outside the soc
 231  * Only necessary until the devicetree-move is complete
 232  */
 233 #define XTI     1
 234 struct samsung_fixed_rate_clock s3c2412_common_frate_clks[] __initdata = {
 235         FRATE(XTI, "xti", NULL, 0, 0),
 236         FRATE(0, "ext", NULL, 0, 0),
 237 };
 238
 239 static void __init s3c2412_common_clk_register_fixed_ext(
 240                 struct samsung_clk_provider *ctx,
 241                 unsigned long xti_f, unsigned long ext_f)
 242 {
 243         /* xtal alias is necessary for the current cpufreq driver */
 244         struct samsung_clock_alias xti_alias = ALIAS(XTI, NULL, "xtal");
 245
 246         s3c2412_common_frate_clks[0].fixed_rate = xti_f;
 247         s3c2412_common_frate_clks[1].fixed_rate = ext_f;
 248         samsung_clk_register_fixed_rate(ctx, s3c2412_common_frate_clks,
 249                                 ARRAY_SIZE(s3c2412_common_frate_clks));
 250
 251         samsung_clk_register_alias(ctx, &xti_alias, 1);
 252 }
 253
 254 void __init s3c2412_common_clk_init(struct device_node *np, unsigned long xti_f,
 255                                     unsigned long ext_f, void __iomem *base)
 256 {
 257         struct samsung_clk_provider *ctx;
 258         int ret;
 259         reg_base = base;
 260
 261         if (np) {
 262                 reg_base = of_iomap(np, 0);
 263                 if (!reg_base)
 264                         panic("%s: failed to map registers\n", __func__);
 265         }
 266
 267         ctx = samsung_clk_init(np, reg_base, NR_CLKS);
 268
 269         /* Register external clocks only in non-dt cases */
 270         if (!np)
 271                 s3c2412_common_clk_register_fixed_ext(ctx, xti_f, ext_f);
 272
 273         /* Register PLLs. */
 274         samsung_clk_register_pll(ctx, s3c2412_plls, ARRAY_SIZE(s3c2412_plls),
 275                                  reg_base);
 276
 277         /* Register common internal clocks. */
 278         samsung_clk_register_mux(ctx, s3c2412_muxes, ARRAY_SIZE(s3c2412_muxes));
 279         samsung_clk_register_div(ctx, s3c2412_dividers,
 280                                           ARRAY_SIZE(s3c2412_dividers));
 281         samsung_clk_register_gate(ctx, s3c2412_gates,
 282                                         ARRAY_SIZE(s3c2412_gates));
 283         samsung_clk_register_fixed_factor(ctx, s3c2412_ffactor,
 284                                           ARRAY_SIZE(s3c2412_ffactor));
 285         samsung_clk_register_alias(ctx, s3c2412_aliases,
 286                                    ARRAY_SIZE(s3c2412_aliases));
 287
 288         s3c2412_clk_sleep_init();
 289
 290         samsung_clk_of_add_provider(np, ctx);
 291
 292         ret = register_restart_handler(&s3c2412_restart_handler);
 293         if (ret)
 294                 pr_warn("cannot register restart handler, %d\n", ret);
 295 }
 296
 297 static void __init s3c2412_clk_init(struct device_node *np)
 298 {
 299         s3c2412_common_clk_init(np, 0, 0, 0);
 300 }
 301 CLK_OF_DECLARE(s3c2412_clk, "samsung,s3c2412-clock", s3c2412_clk_init);