clk/ti/clockdomain.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * OMAP clockdomain support
0004  *
0005  * Copyright (C) 2013 Texas Instruments, Inc.
0006  *
0007  * Tero Kristo <t-kristo@ti.com>
0008  */
0009
0010 #include <linux/clk.h>
0011 #include <linux/clk-provider.h>
0012 #include <linux/slab.h>
0013 #include <linux/of.h>
0014 #include <linux/of_address.h>
0015 #include <linux/clk/ti.h>
0016
0017 #include "clock.h"
0018
0019 #undef pr_fmt
0020 #define pr_fmt(fmt) "%s: " fmt, __func__
0021
0022 /**
0023  * omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
0024  * @hw: struct clk_hw * of the clock being enabled
0025  *
0026  * Increment the usecount of the clockdomain of the clock pointed to
0027  * by @hw; if the usecount is 1, the clockdomain will be "enabled."
0028  * Only needed for clocks that don't use omap2_dflt_clk_enable() as
0029  * their enable function pointer.  Passes along the return value of
0030  * clkdm_clk_enable(), -EINVAL if @hw is not associated with a
0031  * clockdomain, or 0 if clock framework-based clockdomain control is
0032  * not implemented.
0033  */
0034 int omap2_clkops_enable_clkdm(struct clk_hw *hw)
0035 {
0036     struct clk_hw_omap *clk;
0037     int ret = 0;
0038
0039     clk = to_clk_hw_omap(hw);
0040
0041     if (unlikely(!clk->clkdm)) {
0042         pr_err("%s: %s: no clkdm set ?!\n", __func__,
0043                clk_hw_get_name(hw));
0044         return -EINVAL;
0045     }
0046
0047     if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
0048         pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
0049                __func__, clk_hw_get_name(hw));
0050         return 0;
0051     }
0052
0053     ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
0054     WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
0055          __func__, clk_hw_get_name(hw), clk->clkdm_name, ret);
0056
0057     return ret;
0058 }
0059
0060 /**
0061  * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
0062  * @hw: struct clk_hw * of the clock being disabled
0063  *
0064  * Decrement the usecount of the clockdomain of the clock pointed to
0065  * by @hw; if the usecount is 0, the clockdomain will be "disabled."
0066  * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
0067  * disable function pointer.  No return value.
0068  */
0069 void omap2_clkops_disable_clkdm(struct clk_hw *hw)
0070 {
0071     struct clk_hw_omap *clk;
0072
0073     clk = to_clk_hw_omap(hw);
0074
0075     if (unlikely(!clk->clkdm)) {
0076         pr_err("%s: %s: no clkdm set ?!\n", __func__,
0077                clk_hw_get_name(hw));
0078         return;
0079     }
0080
0081     if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
0082         pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
0083                __func__, clk_hw_get_name(hw));
0084         return;
0085     }
0086
0087     ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
0088 }
0089
0090 /**
0091  * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
0092  * @hw: Pointer to clk_hw_omap used to obtain OMAP clock struct ptr to use
0093  *
0094  * Convert a clockdomain name stored in a struct clk 'clk' into a
0095  * clockdomain pointer, and save it into the struct clk.  Intended to be
0096  * called during clk_register(). Returns 0 on success, -EERROR otherwise.
0097  */
0098 int omap2_init_clk_clkdm(struct clk_hw *hw)
0099 {
0100     struct clk_hw_omap *clk = to_clk_hw_omap(hw);
0101     struct clockdomain *clkdm;
0102     const char *clk_name;
0103
0104     if (!clk->clkdm_name)
0105         return 0;
0106
0107     clk_name = __clk_get_name(hw->clk);
0108
0109     clkdm = ti_clk_ll_ops->clkdm_lookup(clk->clkdm_name);
0110     if (clkdm) {
0111         pr_debug("clock: associated clk %s to clkdm %s\n",
0112              clk_name, clk->clkdm_name);
0113         clk->clkdm = clkdm;
0114     } else {
0115         pr_debug("clock: could not associate clk %s to clkdm %s\n",
0116              clk_name, clk->clkdm_name);
0117     }
0118
0119     return 0;
0120 }
0121
0122 static void __init of_ti_clockdomain_setup(struct device_node *node)
0123 {
0124     struct clk *clk;
0125     struct clk_hw *clk_hw;
0126     const char *clkdm_name = ti_dt_clk_name(node);
0127     int i;
0128     unsigned int num_clks;
0129
0130     num_clks = of_clk_get_parent_count(node);
0131
0132     for (i = 0; i < num_clks; i++) {
0133         clk = of_clk_get(node, i);
0134         if (IS_ERR(clk)) {
0135             pr_err("%s: Failed get %pOF' clock nr %d (%ld)\n",
0136                    __func__, node, i, PTR_ERR(clk));
0137             continue;
0138         }
0139         clk_hw = __clk_get_hw(clk);
0140         if (!omap2_clk_is_hw_omap(clk_hw)) {
0141             pr_warn("can't setup clkdm for basic clk %s\n",
0142                 __clk_get_name(clk));
0143             clk_put(clk);
0144             continue;
0145         }
0146         to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
0147         omap2_init_clk_clkdm(clk_hw);
0148         clk_put(clk);
0149     }
0150 }
0151
0152 static const struct of_device_id ti_clkdm_match_table[] __initconst = {
0153     { .compatible = "ti,clockdomain" },
0154     { }
0155 };
0156
0157 /**
0158  * ti_dt_clockdomains_setup - setup device tree clockdomains
0159  *
0160  * Initializes clockdomain nodes for a SoC. This parses through all the
0161  * nodes with compatible = "ti,clockdomain", and add the clockdomain
0162  * info for all the clocks listed under these. This function shall be
0163  * called after rest of the DT clock init has completed and all
0164  * clock nodes have been registered.
0165  */
0166 void __init ti_dt_clockdomains_setup(void)
0167 {
0168     struct device_node *np;
0169     for_each_matching_node(np, ti_clkdm_match_table) {
0170         of_ti_clockdomain_setup(np);
0171     }
0172 }