/* * Copyright (C) 2013 Broadcom Corporation * Copyright 2013 Linaro Limited * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation version 2. * * This program is distributed "as is" WITHOUT ANY WARRANTY of any * kind, whether express or implied; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/io.h> #include <linux/of_address.h> #include "clk-kona.h" /* These are used when a selector or trigger is found to be unneeded */ #define selector_clear_exists(sel) ((sel)->width = 0) #define trigger_clear_exists(trig) FLAG_CLEAR(trig, TRIG, EXISTS) LIST_HEAD(ccu_list); /* The list of set up CCUs */ /* Validity checking */ static bool ccu_data_offsets_valid(struct ccu_data *ccu) { struct ccu_policy *ccu_policy = &ccu->policy; u32 limit; limit = ccu->range - sizeof(u32); limit = round_down(limit, sizeof(u32)); if (ccu_policy_exists(ccu_policy)) { if (ccu_policy->enable.offset > limit) { pr_err("%s: bad policy enable offset for %s " "(%u > %u)\n", __func__, ccu->name, ccu_policy->enable.offset, limit); return false; } if (ccu_policy->control.offset > limit) { pr_err("%s: bad policy control offset for %s " "(%u > %u)\n", __func__, ccu->name, ccu_policy->control.offset, limit); return false; } } return true; } static bool clk_requires_trigger(struct kona_clk *bcm_clk) { struct peri_clk_data *peri = bcm_clk->u.peri; struct bcm_clk_sel *sel; struct bcm_clk_div *div; if (bcm_clk->type != bcm_clk_peri) return false; sel = &peri->sel; if (sel->parent_count && selector_exists(sel)) return true; div = &peri->div; if (!divider_exists(div)) return false; /* Fixed dividers don't need triggers */ if (!divider_is_fixed(div)) return true; div = &peri->pre_div; return divider_exists(div) && !divider_is_fixed(div); } static bool peri_clk_data_offsets_valid(struct kona_clk *bcm_clk) { struct peri_clk_data *peri; struct bcm_clk_policy *policy; struct bcm_clk_gate *gate; struct bcm_clk_hyst *hyst; struct bcm_clk_div *div; struct bcm_clk_sel *sel; struct bcm_clk_trig *trig; const char *name; u32 range; u32 limit; BUG_ON(bcm_clk->type != bcm_clk_peri); peri = bcm_clk->u.peri; name = bcm_clk->init_data.name; range = bcm_clk->ccu->range; limit = range - sizeof(u32); limit = round_down(limit, sizeof(u32)); policy = &peri->policy; if (policy_exists(policy)) { if (policy->offset > limit) { pr_err("%s: bad policy offset for %s (%u > %u)\n", __func__, name, policy->offset, limit); return false; } } gate = &peri->gate; hyst = &peri->hyst; if (gate_exists(gate)) { if (gate->offset > limit) { pr_err("%s: bad gate offset for %s (%u > %u)\n", __func__, name, gate->offset, limit); return false; } if (hyst_exists(hyst)) { if (hyst->offset > limit) { pr_err("%s: bad hysteresis offset for %s " "(%u > %u)\n", __func__, name, hyst->offset, limit); return false; } } } else if (hyst_exists(hyst)) { pr_err("%s: hysteresis but no gate for %s\n", __func__, name); return false; } div = &peri->div; if (divider_exists(div)) { if (div->u.s.offset > limit) { pr_err("%s: bad divider offset for %s (%u > %u)\n", __func__, name, div->u.s.offset, limit); return false; } } div = &peri->pre_div; if (divider_exists(div)) { if (div->u.s.offset > limit) { pr_err("%s: bad pre-divider offset for %s " "(%u > %u)\n", __func__, name, div->u.s.offset, limit); return false; } } sel = &peri->sel; if (selector_exists(sel)) { if (sel->offset > limit) { pr_err("%s: bad selector offset for %s (%u > %u)\n", __func__, name, sel->offset, limit); return false; } } trig = &peri->trig; if (trigger_exists(trig)) { if (trig->offset > limit) { pr_err("%s: bad trigger offset for %s (%u > %u)\n", __func__, name, trig->offset, limit); return false; } } trig = &peri->pre_trig; if (trigger_exists(trig)) { if (trig->offset > limit) { pr_err("%s: bad pre-trigger offset for %s (%u > %u)\n", __func__, name, trig->offset, limit); return false; } } return true; } /* A bit position must be less than the number of bits in a 32-bit register. */ static bool bit_posn_valid(u32 bit_posn, const char *field_name, const char *clock_name) { u32 limit = BITS_PER_BYTE * sizeof(u32) - 1; if (bit_posn > limit) { pr_err("%s: bad %s bit for %s (%u > %u)\n", __func__, field_name, clock_name, bit_posn, limit); return false; } return true; } /* * A bitfield must be at least 1 bit wide. Both the low-order and * high-order bits must lie within a 32-bit register. We require * fields to be less than 32 bits wide, mainly because we use * shifting to produce field masks, and shifting a full word width * is not well-defined by the C standard. */ static bool bitfield_valid(u32 shift, u32 width, const char *field_name, const char *clock_name) { u32 limit = BITS_PER_BYTE * sizeof(u32); if (!width) { pr_err("%s: bad %s field width 0 for %s\n", __func__, field_name, clock_name); return false; } if (shift + width > limit) { pr_err("%s: bad %s for %s (%u + %u > %u)\n", __func__, field_name, clock_name, shift, width, limit); return false; } return true; } static bool ccu_policy_valid(struct ccu_policy *ccu_policy, const char *ccu_name) { struct bcm_lvm_en *enable = &ccu_policy->enable; struct bcm_policy_ctl *control; if (!bit_posn_valid(enable->bit, "policy enable", ccu_name)) return false; control = &ccu_policy->control; if (!bit_posn_valid(control->go_bit, "policy control GO", ccu_name)) return false; if (!bit_posn_valid(control->atl_bit, "policy control ATL", ccu_name)) return false; if (!bit_posn_valid(control->ac_bit, "policy control AC", ccu_name)) return false; return true; } static bool policy_valid(struct bcm_clk_policy *policy, const char *clock_name) { if (!bit_posn_valid(policy->bit, "policy", clock_name)) return false; return true; } /* * All gates, if defined, have a status bit, and for hardware-only * gates, that's it. Gates that can be software controlled also * have an enable bit. And a gate that can be hardware or software * controlled will have a hardware/software select bit. */ static bool gate_valid(struct bcm_clk_gate *gate, const char *field_name, const char *clock_name) { if (!bit_posn_valid(gate->status_bit, "gate status", clock_name)) return false; if (gate_is_sw_controllable(gate)) { if (!bit_posn_valid(gate->en_bit, "gate enable", clock_name)) return false; if (gate_is_hw_controllable(gate)) { if (!bit_posn_valid(gate->hw_sw_sel_bit, "gate hw/sw select", clock_name)) return false; } } else { BUG_ON(!gate_is_hw_controllable(gate)); } return true; } static bool hyst_valid(struct bcm_clk_hyst *hyst, const char *clock_name) { if (!bit_posn_valid(hyst->en_bit, "hysteresis enable", clock_name)) return false; if (!bit_posn_valid(hyst->val_bit, "hysteresis value", clock_name)) return false; return true; } /* * A selector bitfield must be valid. Its parent_sel array must * also be reasonable for the field. */ static bool sel_valid(struct bcm_clk_sel *sel, const char *field_name, const char *clock_name) { if (!bitfield_valid(sel->shift, sel->width, field_name, clock_name)) return false; if (sel->parent_count) { u32 max_sel; u32 limit; /* * Make sure the selector field can hold all the * selector values we expect to be able to use. A * clock only needs to have a selector defined if it * has more than one parent. And in that case the * highest selector value will be in the last entry * in the array. */ max_sel = sel->parent_sel[sel->parent_count - 1]; limit = (1 << sel->width) - 1; if (max_sel > limit) { pr_err("%s: bad selector for %s " "(%u needs > %u bits)\n", __func__, clock_name, max_sel, sel->width); return false; } } else { pr_warn("%s: ignoring selector for %s (no parents)\n", __func__, clock_name); selector_clear_exists(sel); kfree(sel->parent_sel); sel->parent_sel = NULL; } return true; } /* * A fixed divider just needs to be non-zero. A variable divider * has to have a valid divider bitfield, and if it has a fraction, * the width of the fraction must not be no more than the width of * the divider as a whole. */ static bool div_valid(struct bcm_clk_div *div, const char *field_name, const char *clock_name) { if (divider_is_fixed(div)) { /* Any fixed divider value but 0 is OK */ if (div->u.fixed == 0) { pr_err("%s: bad %s fixed value 0 for %s\n", __func__, field_name, clock_name); return false; } return true; } if (!bitfield_valid(div->u.s.shift, div->u.s.width, field_name, clock_name)) return false; if (divider_has_fraction(div)) if (div->u.s.frac_width > div->u.s.width) { pr_warn("%s: bad %s fraction width for %s (%u > %u)\n", __func__, field_name, clock_name, div->u.s.frac_width, div->u.s.width); return false; } return true; } /* * If a clock has two dividers, the combined number of fractional * bits must be representable in a 32-bit unsigned value. This * is because we scale up a dividend using both dividers before * dividing to improve accuracy, and we need to avoid overflow. */ static bool kona_dividers_valid(struct kona_clk *bcm_clk) { struct peri_clk_data *peri = bcm_clk->u.peri; struct bcm_clk_div *div; struct bcm_clk_div *pre_div; u32 limit; BUG_ON(bcm_clk->type != bcm_clk_peri); if (!divider_exists(&peri->div) || !divider_exists(&peri->pre_div)) return true; div = &peri->div; pre_div = &peri->pre_div; if (divider_is_fixed(div) || divider_is_fixed(pre_div)) return true; limit = BITS_PER_BYTE * sizeof(u32); return div->u.s.frac_width + pre_div->u.s.frac_width <= limit; } /* A trigger just needs to represent a valid bit position */ static bool trig_valid(struct bcm_clk_trig *trig, const char *field_name, const char *clock_name) { return bit_posn_valid(trig->bit, field_name, clock_name); } /* Determine whether the set of peripheral clock registers are valid. */ static bool peri_clk_data_valid(struct kona_clk *bcm_clk) { struct peri_clk_data *peri; struct bcm_clk_policy *policy; struct bcm_clk_gate *gate; struct bcm_clk_hyst *hyst; struct bcm_clk_sel *sel; struct bcm_clk_div *div; struct bcm_clk_div *pre_div; struct bcm_clk_trig *trig; const char *name; BUG_ON(bcm_clk->type != bcm_clk_peri); /* * First validate register offsets. This is the only place * where we need something from the ccu, so we do these * together. */ if (!peri_clk_data_offsets_valid(bcm_clk)) return false; peri = bcm_clk->u.peri; name = bcm_clk->init_data.name; policy = &peri->policy; if (policy_exists(policy) && !policy_valid(policy, name)) return false; gate = &peri->gate; if (gate_exists(gate) && !gate_valid(gate, "gate", name)) return false; hyst = &peri->hyst; if (hyst_exists(hyst) && !hyst_valid(hyst, name)) return false; sel = &peri->sel; if (selector_exists(sel)) { if (!sel_valid(sel, "selector", name)) return false; } else if (sel->parent_count > 1) { pr_err("%s: multiple parents but no selector for %s\n", __func__, name); return false; } div = &peri->div; pre_div = &peri->pre_div; if (divider_exists(div)) { if (!div_valid(div, "divider", name)) return false; if (divider_exists(pre_div)) if (!div_valid(pre_div, "pre-divider", name)) return false; } else if (divider_exists(pre_div)) { pr_err("%s: pre-divider but no divider for %s\n", __func__, name); return false; } trig = &peri->trig; if (trigger_exists(trig)) { if (!trig_valid(trig, "trigger", name)) return false; if (trigger_exists(&peri->pre_trig)) { if (!trig_valid(trig, "pre-trigger", name)) { return false; } } if (!clk_requires_trigger(bcm_clk)) { pr_warn("%s: ignoring trigger for %s (not needed)\n", __func__, name); trigger_clear_exists(trig); } } else if (trigger_exists(&peri->pre_trig)) { pr_err("%s: pre-trigger but no trigger for %s\n", __func__, name); return false; } else if (clk_requires_trigger(bcm_clk)) { pr_err("%s: required trigger missing for %s\n", __func__, name); return false; } return kona_dividers_valid(bcm_clk); } static bool kona_clk_valid(struct kona_clk *bcm_clk) { switch (bcm_clk->type) { case bcm_clk_peri: if (!peri_clk_data_valid(bcm_clk)) return false; break; default: pr_err("%s: unrecognized clock type (%d)\n", __func__, (int)bcm_clk->type); return false; } return true; } /* * Scan an array of parent clock names to determine whether there * are any entries containing BAD_CLK_NAME. Such entries are * placeholders for non-supported clocks. Keep track of the * position of each clock name in the original array. * * Allocates an array of pointers to to hold the names of all * non-null entries in the original array, and returns a pointer to * that array in *names. This will be used for registering the * clock with the common clock code. On successful return, * *count indicates how many entries are in that names array. * * If there is more than one entry in the resulting names array, * another array is allocated to record the parent selector value * for each (defined) parent clock. This is the value that * represents this parent clock in the clock's source selector * register. The position of the clock in the original parent array * defines that selector value. The number of entries in this array * is the same as the number of entries in the parent names array. * * The array of selector values is returned. If the clock has no * parents, no selector is required and a null pointer is returned. * * Returns a null pointer if the clock names array supplied was * null. (This is not an error.) * * Returns a pointer-coded error if an error occurs. */ static u32 *parent_process(const char *clocks[], u32 *count, const char ***names) { static const char **parent_names; static u32 *parent_sel; const char **clock; u32 parent_count; u32 bad_count = 0; u32 orig_count; u32 i; u32 j; *count = 0; /* In case of early return */ *names = NULL; if (!clocks) return NULL; /* * Count the number of names in the null-terminated array, * and find out how many of those are actually clock names. */ for (clock = clocks; *clock; clock++) if (*clock == BAD_CLK_NAME) bad_count++; orig_count = (u32)(clock - clocks); parent_count = orig_count - bad_count; /* If all clocks are unsupported, we treat it as no clock */ if (!parent_count) return NULL; /* Avoid exceeding our parent clock limit */ if (parent_count > PARENT_COUNT_MAX) { pr_err("%s: too many parents (%u > %u)\n", __func__, parent_count, PARENT_COUNT_MAX); return ERR_PTR(-EINVAL); } /* * There is one parent name for each defined parent clock. * We also maintain an array containing the selector value * for each defined clock. If there's only one clock, the * selector is not required, but we allocate space for the * array anyway to keep things simple. */ parent_names = kmalloc(parent_count * sizeof(parent_names), GFP_KERNEL); if (!parent_names) { pr_err("%s: error allocating %u parent names\n", __func__, parent_count); return ERR_PTR(-ENOMEM); } /* There is at least one parent, so allocate a selector array */ parent_sel = kmalloc(parent_count * sizeof(*parent_sel), GFP_KERNEL); if (!parent_sel) { pr_err("%s: error allocating %u parent selectors\n", __func__, parent_count); kfree(parent_names); return ERR_PTR(-ENOMEM); } /* Now fill in the parent names and selector arrays */ for (i = 0, j = 0; i < orig_count; i++) { if (clocks[i] != BAD_CLK_NAME) { parent_names[j] = clocks[i]; parent_sel[j] = i; j++; } } *names = parent_names; *count = parent_count; return parent_sel; } static int clk_sel_setup(const char **clocks, struct bcm_clk_sel *sel, struct clk_init_data *init_data) { const char **parent_names = NULL; u32 parent_count = 0; u32 *parent_sel; /* * If a peripheral clock has multiple parents, the value * used by the hardware to select that parent is represented * by the parent clock's position in the "clocks" list. Some * values don't have defined or supported clocks; these will * have BAD_CLK_NAME entries in the parents[] array. The * list is terminated by a NULL entry. * * We need to supply (only) the names of defined parent * clocks when registering a clock though, so we use an * array of parent selector values to map between the * indexes the common clock code uses and the selector * values we need. */ parent_sel = parent_process(clocks, &parent_count, &parent_names); if (IS_ERR(parent_sel)) { int ret = PTR_ERR(parent_sel); pr_err("%s: error processing parent clocks for %s (%d)\n", __func__, init_data->name, ret); return ret; } init_data->parent_names = parent_names; init_data->num_parents = parent_count; sel->parent_count = parent_count; sel->parent_sel = parent_sel; return 0; } static void clk_sel_teardown(struct bcm_clk_sel *sel, struct clk_init_data *init_data) { kfree(sel->parent_sel); sel->parent_sel = NULL; sel->parent_count = 0; init_data->num_parents = 0; kfree(init_data->parent_names); init_data->parent_names = NULL; } static void peri_clk_teardown(struct peri_clk_data *data, struct clk_init_data *init_data) { clk_sel_teardown(&data->sel, init_data); } /* * Caller is responsible for freeing the parent_names[] and * parent_sel[] arrays in the peripheral clock's "data" structure * that can be assigned if the clock has one or more parent clocks * associated with it. */ static int peri_clk_setup(struct peri_clk_data *data, struct clk_init_data *init_data) { init_data->flags = CLK_IGNORE_UNUSED; return clk_sel_setup(data->clocks, &data->sel, init_data); } static void bcm_clk_teardown(struct kona_clk *bcm_clk) { switch (bcm_clk->type) { case bcm_clk_peri: peri_clk_teardown(bcm_clk->u.data, &bcm_clk->init_data); break; default: break; } bcm_clk->u.data = NULL; bcm_clk->type = bcm_clk_none; } static void kona_clk_teardown(struct clk *clk) { struct clk_hw *hw; struct kona_clk *bcm_clk; if (!clk) return; hw = __clk_get_hw(clk); if (!hw) { pr_err("%s: clk %p has null hw pointer\n", __func__, clk); return; } clk_unregister(clk); bcm_clk = to_kona_clk(hw); bcm_clk_teardown(bcm_clk); } struct clk *kona_clk_setup(struct kona_clk *bcm_clk) { struct clk_init_data *init_data = &bcm_clk->init_data; struct clk *clk = NULL; switch (bcm_clk->type) { case bcm_clk_peri: if (peri_clk_setup(bcm_clk->u.data, init_data)) return NULL; break; default: pr_err("%s: clock type %d invalid for %s\n", __func__, (int)bcm_clk->type, init_data->name); return NULL; } /* Make sure everything makes sense before we set it up */ if (!kona_clk_valid(bcm_clk)) { pr_err("%s: clock data invalid for %s\n", __func__, init_data->name); goto out_teardown; } bcm_clk->hw.init = init_data; clk = clk_register(NULL, &bcm_clk->hw); if (IS_ERR(clk)) { pr_err("%s: error registering clock %s (%ld)\n", __func__, init_data->name, PTR_ERR(clk)); goto out_teardown; } BUG_ON(!clk); return clk; out_teardown: bcm_clk_teardown(bcm_clk); return NULL; } static void ccu_clks_teardown(struct ccu_data *ccu) { u32 i; for (i = 0; i < ccu->clk_data.clk_num; i++) kona_clk_teardown(ccu->clk_data.clks[i]); kfree(ccu->clk_data.clks); } static void kona_ccu_teardown(struct ccu_data *ccu) { kfree(ccu->clk_data.clks); ccu->clk_data.clks = NULL; if (!ccu->base) return; of_clk_del_provider(ccu->node); /* safe if never added */ ccu_clks_teardown(ccu); list_del(&ccu->links); of_node_put(ccu->node); ccu->node = NULL; iounmap(ccu->base); ccu->base = NULL; } static bool ccu_data_valid(struct ccu_data *ccu) { struct ccu_policy *ccu_policy; if (!ccu_data_offsets_valid(ccu)) return false; ccu_policy = &ccu->policy; if (ccu_policy_exists(ccu_policy)) if (!ccu_policy_valid(ccu_policy, ccu->name)) return false; return true; } /* * Set up a CCU. Call the provided ccu_clks_setup callback to * initialize the array of clocks provided by the CCU. */ void __init kona_dt_ccu_setup(struct ccu_data *ccu, struct device_node *node) { struct resource res = { 0 }; resource_size_t range; unsigned int i; int ret; if (ccu->clk_data.clk_num) { size_t size; size = ccu->clk_data.clk_num * sizeof(*ccu->clk_data.clks); ccu->clk_data.clks = kzalloc(size, GFP_KERNEL); if (!ccu->clk_data.clks) { pr_err("%s: unable to allocate %u clocks for %s\n", __func__, ccu->clk_data.clk_num, node->name); return; } } ret = of_address_to_resource(node, 0, &res); if (ret) { pr_err("%s: no valid CCU registers found for %s\n", __func__, node->name); goto out_err; } range = resource_size(&res); if (range > (resource_size_t)U32_MAX) { pr_err("%s: address range too large for %s\n", __func__, node->name); goto out_err; } ccu->range = (u32)range; if (!ccu_data_valid(ccu)) { pr_err("%s: ccu data not valid for %s\n", __func__, node->name); goto out_err; } ccu->base = ioremap(res.start, ccu->range); if (!ccu->base) { pr_err("%s: unable to map CCU registers for %s\n", __func__, node->name); goto out_err; } ccu->node = of_node_get(node); list_add_tail(&ccu->links, &ccu_list); /* * Set up each defined kona clock and save the result in * the clock framework clock array (in ccu->data). Then * register as a provider for these clocks. */ for (i = 0; i < ccu->clk_data.clk_num; i++) { if (!ccu->kona_clks[i].ccu) continue; ccu->clk_data.clks[i] = kona_clk_setup(&ccu->kona_clks[i]); } ret = of_clk_add_provider(node, of_clk_src_onecell_get, &ccu->clk_data); if (ret) { pr_err("%s: error adding ccu %s as provider (%d)\n", __func__, node->name, ret); goto out_err; } if (!kona_ccu_init(ccu)) pr_err("Broadcom %s initialization had errors\n", node->name); return; out_err: kona_ccu_teardown(ccu); pr_err("Broadcom %s setup aborted\n", node->name); }