arch/arm/mach-shmobile/clock-emev2.c

   1 /*
   2  * Emma Mobile EV2 clock framework support
   3  *
   4  * Copyright (C) 2012  Magnus Damm
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #include <linux/init.h>
  20 #include <linux/kernel.h>
  21 #include <linux/io.h>
  22 #include <linux/sh_clk.h>
  23 #include <linux/clkdev.h>
  24 #include <mach/common.h>
  25
  26 #define EMEV2_SMU_BASE 0xe0110000
  27
  28 /* EMEV2 SMU registers */
  29 #define USIAU0_RSTCTRL 0x094
  30 #define USIBU1_RSTCTRL 0x0ac
  31 #define USIBU2_RSTCTRL 0x0b0
  32 #define USIBU3_RSTCTRL 0x0b4
  33 #define STI_RSTCTRL 0x124
  34 #define USIAU0GCLKCTRL 0x4a0
  35 #define USIBU1GCLKCTRL 0x4b8
  36 #define USIBU2GCLKCTRL 0x4bc
  37 #define USIBU3GCLKCTRL 0x04c0
  38 #define STIGCLKCTRL 0x528
  39 #define USIAU0SCLKDIV 0x61c
  40 #define USIB2SCLKDIV 0x65c
  41 #define USIB3SCLKDIV 0x660
  42 #define STI_CLKSEL 0x688
  43 #define SMU_GENERAL_REG0 0x7c0
  44
  45 /* not pretty, but hey */
  46 static void __iomem *smu_base;
  47
  48 static void emev2_smu_write(unsigned long value, int offs)
  49 {
  50         BUG_ON(!smu_base || (offs >= PAGE_SIZE));
  51         iowrite32(value, smu_base + offs);
  52 }
  53
  54 void emev2_set_boot_vector(unsigned long value)
  55 {
  56         emev2_smu_write(value, SMU_GENERAL_REG0);
  57 }
  58
  59 static struct clk_mapping smu_mapping = {
  60         .phys   = EMEV2_SMU_BASE,
  61         .len    = PAGE_SIZE,
  62 };
  63
  64 /* Fixed 32 KHz root clock from C32K pin */
  65 static struct clk c32k_clk = {
  66         .rate           = 32768,
  67         .mapping        = &smu_mapping,
  68 };
  69
  70 /* PLL3 multiplies C32K with 7000 */
  71 static unsigned long pll3_recalc(struct clk *clk)
  72 {
  73         return clk->parent->rate * 7000;
  74 }
  75
  76 static struct sh_clk_ops pll3_clk_ops = {
  77         .recalc         = pll3_recalc,
  78 };
  79
  80 static struct clk pll3_clk = {
  81         .ops            = &pll3_clk_ops,
  82         .parent         = &c32k_clk,
  83 };
  84
  85 static struct clk *main_clks[] = {
  86         &c32k_clk,
  87         &pll3_clk,
  88 };
  89
  90 enum { SCLKDIV_USIAU0, SCLKDIV_USIBU2, SCLKDIV_USIBU1, SCLKDIV_USIBU3,
  91         SCLKDIV_NR };
  92
  93 #define SCLKDIV(_reg, _shift)                   \
  94 {                                                               \
  95         .parent         = &pll3_clk,                            \
  96         .enable_reg     = IOMEM(EMEV2_SMU_BASE + (_reg)),       \
  97         .enable_bit     = _shift,                               \
  98 }
  99
 100 static struct clk sclkdiv_clks[SCLKDIV_NR] = {
 101         [SCLKDIV_USIAU0] = SCLKDIV(USIAU0SCLKDIV, 0),
 102         [SCLKDIV_USIBU2] = SCLKDIV(USIB2SCLKDIV, 16),
 103         [SCLKDIV_USIBU1] = SCLKDIV(USIB2SCLKDIV, 0),
 104         [SCLKDIV_USIBU3] = SCLKDIV(USIB3SCLKDIV, 0),
 105 };
 106
 107 enum { GCLK_USIAU0_SCLK, GCLK_USIBU1_SCLK, GCLK_USIBU2_SCLK, GCLK_USIBU3_SCLK,
 108         GCLK_STI_SCLK,
 109         GCLK_NR };
 110
 111 #define GCLK_SCLK(_parent, _reg) \
 112 {                                                               \
 113         .parent         = _parent,                              \
 114         .enable_reg     = IOMEM(EMEV2_SMU_BASE + (_reg)),       \
 115         .enable_bit     = 1, /* SCLK_GCC */                     \
 116 }
 117
 118 static struct clk gclk_clks[GCLK_NR] = {
 119         [GCLK_USIAU0_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIAU0],
 120                                        USIAU0GCLKCTRL),
 121         [GCLK_USIBU1_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU1],
 122                                        USIBU1GCLKCTRL),
 123         [GCLK_USIBU2_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU2],
 124                                        USIBU2GCLKCTRL),
 125         [GCLK_USIBU3_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU3],
 126                                        USIBU3GCLKCTRL),
 127         [GCLK_STI_SCLK] = GCLK_SCLK(&c32k_clk, STIGCLKCTRL),
 128 };
 129
 130 static int emev2_gclk_enable(struct clk *clk)
 131 {
 132         iowrite32(ioread32(clk->mapped_reg) | (1 << clk->enable_bit),
 133                   clk->mapped_reg);
 134         return 0;
 135 }
 136
 137 static void emev2_gclk_disable(struct clk *clk)
 138 {
 139         iowrite32(ioread32(clk->mapped_reg) & ~(1 << clk->enable_bit),
 140                   clk->mapped_reg);
 141 }
 142
 143 static struct sh_clk_ops emev2_gclk_clk_ops = {
 144         .enable         = emev2_gclk_enable,
 145         .disable        = emev2_gclk_disable,
 146         .recalc         = followparent_recalc,
 147 };
 148
 149 static int __init emev2_gclk_register(struct clk *clks, int nr)
 150 {
 151         struct clk *clkp;
 152         int ret = 0;
 153         int k;
 154
 155         for (k = 0; !ret && (k < nr); k++) {
 156                 clkp = clks + k;
 157                 clkp->ops = &emev2_gclk_clk_ops;
 158                 ret |= clk_register(clkp);
 159         }
 160
 161         return ret;
 162 }
 163
 164 static unsigned long emev2_sclkdiv_recalc(struct clk *clk)
 165 {
 166         unsigned int sclk_div;
 167
 168         sclk_div = (ioread32(clk->mapped_reg) >> clk->enable_bit) & 0xff;
 169
 170         return clk->parent->rate / (sclk_div + 1);
 171 }
 172
 173 static struct sh_clk_ops emev2_sclkdiv_clk_ops = {
 174         .recalc         = emev2_sclkdiv_recalc,
 175 };
 176
 177 static int __init emev2_sclkdiv_register(struct clk *clks, int nr)
 178 {
 179         struct clk *clkp;
 180         int ret = 0;
 181         int k;
 182
 183         for (k = 0; !ret && (k < nr); k++) {
 184                 clkp = clks + k;
 185                 clkp->ops = &emev2_sclkdiv_clk_ops;
 186                 ret |= clk_register(clkp);
 187         }
 188
 189         return ret;
 190 }
 191
 192 static struct clk_lookup lookups[] = {
 193         CLKDEV_DEV_ID("serial8250-em.0", &gclk_clks[GCLK_USIAU0_SCLK]),
 194         CLKDEV_DEV_ID("e1020000.uart", &gclk_clks[GCLK_USIAU0_SCLK]),
 195         CLKDEV_DEV_ID("serial8250-em.1", &gclk_clks[GCLK_USIBU1_SCLK]),
 196         CLKDEV_DEV_ID("e1030000.uart", &gclk_clks[GCLK_USIBU1_SCLK]),
 197         CLKDEV_DEV_ID("serial8250-em.2", &gclk_clks[GCLK_USIBU2_SCLK]),
 198         CLKDEV_DEV_ID("e1040000.uart", &gclk_clks[GCLK_USIBU2_SCLK]),
 199         CLKDEV_DEV_ID("serial8250-em.3", &gclk_clks[GCLK_USIBU3_SCLK]),
 200         CLKDEV_DEV_ID("e1050000.uart", &gclk_clks[GCLK_USIBU3_SCLK]),
 201         CLKDEV_DEV_ID("em_sti.0", &gclk_clks[GCLK_STI_SCLK]),
 202         CLKDEV_DEV_ID("e0180000.sti", &gclk_clks[GCLK_STI_SCLK]),
 203 };
 204
 205 void __init emev2_clock_init(void)
 206 {
 207         int k, ret = 0;
 208         static int is_setup;
 209
 210         /* yuck, this is ugly as hell, but the non-smp case of clocks
 211          * code is now designed to rely on ioremap() instead of static
 212          * entity maps. in the case of smp we need access to the SMU
 213          * register earlier than ioremap() is actually working without
 214          * any static maps. to enable SMP in ugly but with dynamic
 215          * mappings we have to call emev2_clock_init() from different
 216          * places depending on UP and SMP...
 217          */
 218         if (is_setup++)
 219                 return;
 220
 221         smu_base = ioremap(EMEV2_SMU_BASE, PAGE_SIZE);
 222         BUG_ON(!smu_base);
 223
 224         /* setup STI timer to run on 37.768 kHz and deassert reset */
 225         emev2_smu_write(0, STI_CLKSEL);
 226         emev2_smu_write(1, STI_RSTCTRL);
 227
 228         /* deassert reset for UART0->UART3 */
 229         emev2_smu_write(2, USIAU0_RSTCTRL);
 230         emev2_smu_write(2, USIBU1_RSTCTRL);
 231         emev2_smu_write(2, USIBU2_RSTCTRL);
 232         emev2_smu_write(2, USIBU3_RSTCTRL);
 233
 234         for (k = 0; !ret && (k < ARRAY_SIZE(main_clks)); k++)
 235                 ret = clk_register(main_clks[k]);
 236
 237         if (!ret)
 238                 ret = emev2_sclkdiv_register(sclkdiv_clks, SCLKDIV_NR);
 239
 240         if (!ret)
 241                 ret = emev2_gclk_register(gclk_clks, GCLK_NR);
 242
 243         clkdev_add_table(lookups, ARRAY_SIZE(lookups));
 244
 245         if (!ret)
 246                 shmobile_clk_init();
 247         else
 248                 panic("failed to setup emev2 clocks\n");
 249 }