drivers/clk/ti/gate.c

   1 /*
   2  * OMAP gate clock support
   3  *
   4  * Copyright (C) 2013 Texas Instruments, Inc.
   5  *
   6  * Tero Kristo <t-kristo@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13  * kind, whether express or implied; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/clk-provider.h>
  19 #include <linux/slab.h>
  20 #include <linux/io.h>
  21 #include <linux/of.h>
  22 #include <linux/of_address.h>
  23 #include <linux/clk/ti.h>
  24
  25 #define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
  26
  27 #undef pr_fmt
  28 #define pr_fmt(fmt) "%s: " fmt, __func__
  29
  30 static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk);
  31
  32 static const struct clk_ops omap_gate_clkdm_clk_ops = {
  33         .init           = &omap2_init_clk_clkdm,
  34         .enable         = &omap2_clkops_enable_clkdm,
  35         .disable        = &omap2_clkops_disable_clkdm,
  36 };
  37
  38 static const struct clk_ops omap_gate_clk_ops = {
  39         .init           = &omap2_init_clk_clkdm,
  40         .enable         = &omap2_dflt_clk_enable,
  41         .disable        = &omap2_dflt_clk_disable,
  42         .is_enabled     = &omap2_dflt_clk_is_enabled,
  43 };
  44
  45 static const struct clk_ops omap_gate_clk_hsdiv_restore_ops = {
  46         .init           = &omap2_init_clk_clkdm,
  47         .enable         = &omap36xx_gate_clk_enable_with_hsdiv_restore,
  48         .disable        = &omap2_dflt_clk_disable,
  49         .is_enabled     = &omap2_dflt_clk_is_enabled,
  50 };
  51
  52 /**
  53  * omap36xx_gate_clk_enable_with_hsdiv_restore - enable clocks suffering
  54  *         from HSDivider PWRDN problem Implements Errata ID: i556.
  55  * @clk: DPLL output struct clk
  56  *
  57  * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck,
  58  * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset
  59  * valueafter their respective PWRDN bits are set.  Any dummy write
  60  * (Any other value different from the Read value) to the
  61  * corresponding CM_CLKSEL register will refresh the dividers.
  62  */
  63 static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk)
  64 {
  65         struct clk_divider *parent;
  66         struct clk_hw *parent_hw;
  67         u32 dummy_v, orig_v;
  68         int ret;
  69
  70         /* Clear PWRDN bit of HSDIVIDER */
  71         ret = omap2_dflt_clk_enable(clk);
  72
  73         /* Parent is the x2 node, get parent of parent for the m2 div */
  74         parent_hw = __clk_get_hw(__clk_get_parent(__clk_get_parent(clk->clk)));
  75         parent = to_clk_divider(parent_hw);
  76
  77         /* Restore the dividers */
  78         if (!ret) {
  79                 orig_v = ti_clk_ll_ops->clk_readl(parent->reg);
  80                 dummy_v = orig_v;
  81
  82                 /* Write any other value different from the Read value */
  83                 dummy_v ^= (1 << parent->shift);
  84                 ti_clk_ll_ops->clk_writel(dummy_v, parent->reg);
  85
  86                 /* Write the original divider */
  87                 ti_clk_ll_ops->clk_writel(orig_v, parent->reg);
  88         }
  89
  90         return ret;
  91 }
  92
  93 static void __init _of_ti_gate_clk_setup(struct device_node *node,
  94                                          const struct clk_ops *ops,
  95                                          const struct clk_hw_omap_ops *hw_ops)
  96 {
  97         struct clk *clk;
  98         struct clk_init_data init = { NULL };
  99         struct clk_hw_omap *clk_hw;
 100         const char *clk_name = node->name;
 101         const char *parent_name;
 102         u32 val;
 103
 104         clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
 105         if (!clk_hw)
 106                 return;
 107
 108         clk_hw->hw.init = &init;
 109
 110         init.name = clk_name;
 111         init.ops = ops;
 112
 113         if (ops != &omap_gate_clkdm_clk_ops) {
 114                 clk_hw->enable_reg = ti_clk_get_reg_addr(node, 0);
 115                 if (!clk_hw->enable_reg)
 116                         goto cleanup;
 117
 118                 if (!of_property_read_u32(node, "ti,bit-shift", &val))
 119                         clk_hw->enable_bit = val;
 120         }
 121
 122         clk_hw->ops = hw_ops;
 123
 124         clk_hw->flags = MEMMAP_ADDRESSING;
 125
 126         if (of_clk_get_parent_count(node) != 1) {
 127                 pr_err("%s must have 1 parent\n", clk_name);
 128                 goto cleanup;
 129         }
 130
 131         parent_name = of_clk_get_parent_name(node, 0);
 132         init.parent_names = &parent_name;
 133         init.num_parents = 1;
 134
 135         if (of_property_read_bool(node, "ti,set-rate-parent"))
 136                 init.flags |= CLK_SET_RATE_PARENT;
 137
 138         if (of_property_read_bool(node, "ti,set-bit-to-disable"))
 139                 clk_hw->flags |= INVERT_ENABLE;
 140
 141         clk = clk_register(NULL, &clk_hw->hw);
 142
 143         if (!IS_ERR(clk)) {
 144                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 145                 return;
 146         }
 147
 148 cleanup:
 149         kfree(clk_hw);
 150 }
 151
 152 static void __init
 153 _of_ti_composite_gate_clk_setup(struct device_node *node,
 154                                 const struct clk_hw_omap_ops *hw_ops)
 155 {
 156         struct clk_hw_omap *gate;
 157         u32 val = 0;
 158
 159         gate = kzalloc(sizeof(*gate), GFP_KERNEL);
 160         if (!gate)
 161                 return;
 162
 163         gate->enable_reg = ti_clk_get_reg_addr(node, 0);
 164         if (!gate->enable_reg)
 165                 goto cleanup;
 166
 167         of_property_read_u32(node, "ti,bit-shift", &val);
 168
 169         gate->enable_bit = val;
 170         gate->ops = hw_ops;
 171         gate->flags = MEMMAP_ADDRESSING;
 172
 173         if (!ti_clk_add_component(node, &gate->hw, CLK_COMPONENT_TYPE_GATE))
 174                 return;
 175
 176 cleanup:
 177         kfree(gate);
 178 }
 179
 180 static void __init
 181 of_ti_composite_no_wait_gate_clk_setup(struct device_node *node)
 182 {
 183         _of_ti_composite_gate_clk_setup(node, NULL);
 184 }
 185 CLK_OF_DECLARE(ti_composite_no_wait_gate_clk, "ti,composite-no-wait-gate-clock",
 186                of_ti_composite_no_wait_gate_clk_setup);
 187
 188 #ifdef CONFIG_ARCH_OMAP3
 189 static void __init of_ti_composite_interface_clk_setup(struct device_node *node)
 190 {
 191         _of_ti_composite_gate_clk_setup(node, &clkhwops_iclk_wait);
 192 }
 193 CLK_OF_DECLARE(ti_composite_interface_clk, "ti,composite-interface-clock",
 194                of_ti_composite_interface_clk_setup);
 195 #endif
 196
 197 static void __init of_ti_composite_gate_clk_setup(struct device_node *node)
 198 {
 199         _of_ti_composite_gate_clk_setup(node, &clkhwops_wait);
 200 }
 201 CLK_OF_DECLARE(ti_composite_gate_clk, "ti,composite-gate-clock",
 202                of_ti_composite_gate_clk_setup);
 203
 204
 205 static void __init of_ti_clkdm_gate_clk_setup(struct device_node *node)
 206 {
 207         _of_ti_gate_clk_setup(node, &omap_gate_clkdm_clk_ops, NULL);
 208 }
 209 CLK_OF_DECLARE(ti_clkdm_gate_clk, "ti,clkdm-gate-clock",
 210                of_ti_clkdm_gate_clk_setup);
 211
 212 static void __init of_ti_hsdiv_gate_clk_setup(struct device_node *node)
 213 {
 214         _of_ti_gate_clk_setup(node, &omap_gate_clk_hsdiv_restore_ops,
 215                               &clkhwops_wait);
 216 }
 217 CLK_OF_DECLARE(ti_hsdiv_gate_clk, "ti,hsdiv-gate-clock",
 218                of_ti_hsdiv_gate_clk_setup);
 219
 220 static void __init of_ti_gate_clk_setup(struct device_node *node)
 221 {
 222         _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, NULL);
 223 }
 224 CLK_OF_DECLARE(ti_gate_clk, "ti,gate-clock", of_ti_gate_clk_setup)
 225
 226 static void __init of_ti_wait_gate_clk_setup(struct device_node *node)
 227 {
 228         _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, &clkhwops_wait);
 229 }
 230 CLK_OF_DECLARE(ti_wait_gate_clk, "ti,wait-gate-clock",
 231                of_ti_wait_gate_clk_setup);
 232
 233 #ifdef CONFIG_ARCH_OMAP3
 234 static void __init of_ti_am35xx_gate_clk_setup(struct device_node *node)
 235 {
 236         _of_ti_gate_clk_setup(node, &omap_gate_clk_ops,
 237                               &clkhwops_am35xx_ipss_module_wait);
 238 }
 239 CLK_OF_DECLARE(ti_am35xx_gate_clk, "ti,am35xx-gate-clock",
 240                of_ti_am35xx_gate_clk_setup);
 241
 242 static void __init of_ti_dss_gate_clk_setup(struct device_node *node)
 243 {
 244         _of_ti_gate_clk_setup(node, &omap_gate_clk_ops,
 245                               &clkhwops_omap3430es2_dss_usbhost_wait);
 246 }
 247 CLK_OF_DECLARE(ti_dss_gate_clk, "ti,dss-gate-clock",
 248                of_ti_dss_gate_clk_setup);
 249 #endif