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
  44 /* not pretty, but hey */
  45 static void __iomem *smu_base;
  46
  47 static void emev2_smu_write(unsigned long value, int offs)
  48 {
  49         BUG_ON(!smu_base || (offs >= PAGE_SIZE));
  50         iowrite32(value, smu_base + offs);
  51 }
  52
  53 static struct clk_mapping smu_mapping = {
  54         .phys   = EMEV2_SMU_BASE,
  55         .len    = PAGE_SIZE,
  56 };
  57
  58 /* Fixed 32 KHz root clock from C32K pin */
  59 static struct clk c32k_clk = {
  60         .rate           = 32768,
  61         .mapping        = &smu_mapping,
  62 };
  63
  64 /* PLL3 multiplies C32K with 7000 */
  65 static unsigned long pll3_recalc(struct clk *clk)
  66 {
  67         return clk->parent->rate * 7000;
  68 }
  69
  70 static struct sh_clk_ops pll3_clk_ops = {
  71         .recalc         = pll3_recalc,
  72 };
  73
  74 static struct clk pll3_clk = {
  75         .ops            = &pll3_clk_ops,
  76         .parent         = &c32k_clk,
  77 };
  78
  79 static struct clk *main_clks[] = {
  80         &c32k_clk,
  81         &pll3_clk,
  82 };
  83
  84 enum { SCLKDIV_USIAU0, SCLKDIV_USIBU2, SCLKDIV_USIBU1, SCLKDIV_USIBU3,
  85         SCLKDIV_NR };
  86
  87 #define SCLKDIV(_reg, _shift)                   \
  88 {                                                               \
  89         .parent         = &pll3_clk,                            \
  90         .enable_reg     = IOMEM(EMEV2_SMU_BASE + (_reg)),       \
  91         .enable_bit     = _shift,                               \
  92 }
  93
  94 static struct clk sclkdiv_clks[SCLKDIV_NR] = {
  95         [SCLKDIV_USIAU0] = SCLKDIV(USIAU0SCLKDIV, 0),
  96         [SCLKDIV_USIBU2] = SCLKDIV(USIB2SCLKDIV, 16),
  97         [SCLKDIV_USIBU1] = SCLKDIV(USIB2SCLKDIV, 0),
  98         [SCLKDIV_USIBU3] = SCLKDIV(USIB3SCLKDIV, 0),
  99 };
 100
 101 enum { GCLK_USIAU0_SCLK, GCLK_USIBU1_SCLK, GCLK_USIBU2_SCLK, GCLK_USIBU3_SCLK,
 102         GCLK_STI_SCLK,
 103         GCLK_NR };
 104
 105 #define GCLK_SCLK(_parent, _reg) \
 106 {                                                               \
 107         .parent         = _parent,                              \
 108         .enable_reg     = IOMEM(EMEV2_SMU_BASE + (_reg)),       \
 109         .enable_bit     = 1, /* SCLK_GCC */                     \
 110 }
 111
 112 static struct clk gclk_clks[GCLK_NR] = {
 113         [GCLK_USIAU0_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIAU0],
 114                                        USIAU0GCLKCTRL),
 115         [GCLK_USIBU1_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU1],
 116                                        USIBU1GCLKCTRL),
 117         [GCLK_USIBU2_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU2],
 118                                        USIBU2GCLKCTRL),
 119         [GCLK_USIBU3_SCLK] = GCLK_SCLK(&sclkdiv_clks[SCLKDIV_USIBU3],
 120                                        USIBU3GCLKCTRL),
 121         [GCLK_STI_SCLK] = GCLK_SCLK(&c32k_clk, STIGCLKCTRL),
 122 };
 123
 124 static int emev2_gclk_enable(struct clk *clk)
 125 {
 126         iowrite32(ioread32(clk->mapped_reg) | (1 << clk->enable_bit),
 127                   clk->mapped_reg);
 128         return 0;
 129 }
 130
 131 static void emev2_gclk_disable(struct clk *clk)
 132 {
 133         iowrite32(ioread32(clk->mapped_reg) & ~(1 << clk->enable_bit),
 134                   clk->mapped_reg);
 135 }
 136
 137 static struct sh_clk_ops emev2_gclk_clk_ops = {
 138         .enable         = emev2_gclk_enable,
 139         .disable        = emev2_gclk_disable,
 140         .recalc         = followparent_recalc,
 141 };
 142
 143 static int __init emev2_gclk_register(struct clk *clks, int nr)
 144 {
 145         struct clk *clkp;
 146         int ret = 0;
 147         int k;
 148
 149         for (k = 0; !ret && (k < nr); k++) {
 150                 clkp = clks + k;
 151                 clkp->ops = &emev2_gclk_clk_ops;
 152                 ret |= clk_register(clkp);
 153         }
 154
 155         return ret;
 156 }
 157
 158 static unsigned long emev2_sclkdiv_recalc(struct clk *clk)
 159 {
 160         unsigned int sclk_div;
 161
 162         sclk_div = (ioread32(clk->mapped_reg) >> clk->enable_bit) & 0xff;
 163
 164         return clk->parent->rate / (sclk_div + 1);
 165 }
 166
 167 static struct sh_clk_ops emev2_sclkdiv_clk_ops = {
 168         .recalc         = emev2_sclkdiv_recalc,
 169 };
 170
 171 static int __init emev2_sclkdiv_register(struct clk *clks, int nr)
 172 {
 173         struct clk *clkp;
 174         int ret = 0;
 175         int k;
 176
 177         for (k = 0; !ret && (k < nr); k++) {
 178                 clkp = clks + k;
 179                 clkp->ops = &emev2_sclkdiv_clk_ops;
 180                 ret |= clk_register(clkp);
 181         }
 182
 183         return ret;
 184 }
 185
 186 static struct clk_lookup lookups[] = {
 187         CLKDEV_DEV_ID("serial8250-em.0", &gclk_clks[GCLK_USIAU0_SCLK]),
 188         CLKDEV_DEV_ID("e1020000.uart", &gclk_clks[GCLK_USIAU0_SCLK]),
 189         CLKDEV_DEV_ID("serial8250-em.1", &gclk_clks[GCLK_USIBU1_SCLK]),
 190         CLKDEV_DEV_ID("e1030000.uart", &gclk_clks[GCLK_USIBU1_SCLK]),
 191         CLKDEV_DEV_ID("serial8250-em.2", &gclk_clks[GCLK_USIBU2_SCLK]),
 192         CLKDEV_DEV_ID("e1040000.uart", &gclk_clks[GCLK_USIBU2_SCLK]),
 193         CLKDEV_DEV_ID("serial8250-em.3", &gclk_clks[GCLK_USIBU3_SCLK]),
 194         CLKDEV_DEV_ID("e1050000.uart", &gclk_clks[GCLK_USIBU3_SCLK]),
 195         CLKDEV_DEV_ID("em_sti.0", &gclk_clks[GCLK_STI_SCLK]),
 196         CLKDEV_DEV_ID("e0180000.sti", &gclk_clks[GCLK_STI_SCLK]),
 197 };
 198
 199 void __init emev2_clock_init(void)
 200 {
 201         int k, ret = 0;
 202
 203         smu_base = ioremap(EMEV2_SMU_BASE, PAGE_SIZE);
 204         BUG_ON(!smu_base);
 205
 206         /* setup STI timer to run on 32.768 kHz and deassert reset */
 207         emev2_smu_write(0, STI_CLKSEL);
 208         emev2_smu_write(1, STI_RSTCTRL);
 209
 210         /* deassert reset for UART0->UART3 */
 211         emev2_smu_write(2, USIAU0_RSTCTRL);
 212         emev2_smu_write(2, USIBU1_RSTCTRL);
 213         emev2_smu_write(2, USIBU2_RSTCTRL);
 214         emev2_smu_write(2, USIBU3_RSTCTRL);
 215
 216         for (k = 0; !ret && (k < ARRAY_SIZE(main_clks)); k++)
 217                 ret = clk_register(main_clks[k]);
 218
 219         if (!ret)
 220                 ret = emev2_sclkdiv_register(sclkdiv_clks, SCLKDIV_NR);
 221
 222         if (!ret)
 223                 ret = emev2_gclk_register(gclk_clks, GCLK_NR);
 224
 225         clkdev_add_table(lookups, ARRAY_SIZE(lookups));
 226
 227         if (!ret)
 228                 shmobile_clk_init();
 229         else
 230                 panic("failed to setup emev2 clocks\n");
 231 }