/* * Copyright (C) 2013 Boris BREZILLON * * 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; either version 2 of the License, or * (at your option) any later version. * */ #include #include #include #include #include #include #include #include #include #include #include #include "pmc.h" #define MASTER_SOURCE_MAX 4 #define MASTER_PRES_MASK 0x7 #define MASTER_PRES_MAX MASTER_PRES_MASK #define MASTER_DIV_SHIFT 8 #define MASTER_DIV_MASK 0x3 struct clk_master_characteristics { struct clk_range output; u32 divisors[4]; u8 have_div3_pres; }; struct clk_master_layout { u32 mask; u8 pres_shift; }; #define to_clk_master(hw) container_of(hw, struct clk_master, hw) struct clk_master { struct clk_hw hw; struct at91_pmc *pmc; unsigned int irq; wait_queue_head_t wait; const struct clk_master_layout *layout; const struct clk_master_characteristics *characteristics; }; static irqreturn_t clk_master_irq_handler(int irq, void *dev_id) { struct clk_master *master = (struct clk_master *)dev_id; wake_up(&master->wait); disable_irq_nosync(master->irq); return IRQ_HANDLED; } static int clk_master_prepare(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); struct at91_pmc *pmc = master->pmc; while (!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MCKRDY)) { enable_irq(master->irq); wait_event(master->wait, pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_MCKRDY); } return 0; } static int clk_master_is_prepared(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); return !!(pmc_read(master->pmc, AT91_PMC_SR) & AT91_PMC_MCKRDY); } static unsigned long clk_master_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { u8 pres; u8 div; unsigned long rate = parent_rate; struct clk_master *master = to_clk_master(hw); struct at91_pmc *pmc = master->pmc; const struct clk_master_layout *layout = master->layout; const struct clk_master_characteristics *characteristics = master->characteristics; u32 tmp; pmc_lock(pmc); tmp = pmc_read(pmc, AT91_PMC_MCKR) & layout->mask; pmc_unlock(pmc); pres = (tmp >> layout->pres_shift) & MASTER_PRES_MASK; div = (tmp >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; if (characteristics->have_div3_pres && pres == MASTER_PRES_MAX) rate /= 3; else rate >>= pres; rate /= characteristics->divisors[div]; if (rate < characteristics->output.min) pr_warn("master clk is underclocked"); else if (rate > characteristics->output.max) pr_warn("master clk is overclocked"); return rate; } static u8 clk_master_get_parent(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); struct at91_pmc *pmc = master->pmc; return pmc_read(pmc, AT91_PMC_MCKR) & AT91_PMC_CSS; } static const struct clk_ops master_ops = { .prepare = clk_master_prepare, .is_prepared = clk_master_is_prepared, .recalc_rate = clk_master_recalc_rate, .get_parent = clk_master_get_parent, }; static struct clk * __init at91_clk_register_master(struct at91_pmc *pmc, unsigned int irq, const char *name, int num_parents, const char **parent_names, const struct clk_master_layout *layout, const struct clk_master_characteristics *characteristics) { int ret; struct clk_master *master; struct clk *clk = NULL; struct clk_init_data init; if (!pmc || !irq || !name || !num_parents || !parent_names) return ERR_PTR(-EINVAL); master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return ERR_PTR(-ENOMEM); init.name = name; init.ops = &master_ops; init.parent_names = parent_names; init.num_parents = num_parents; init.flags = 0; master->hw.init = &init; master->layout = layout; master->characteristics = characteristics; master->pmc = pmc; master->irq = irq; init_waitqueue_head(&master->wait); irq_set_status_flags(master->irq, IRQ_NOAUTOEN); ret = request_irq(master->irq, clk_master_irq_handler, IRQF_TRIGGER_HIGH, "clk-master", master); if (ret) { kfree(master); return ERR_PTR(ret); } clk = clk_register(NULL, &master->hw); if (IS_ERR(clk)) { free_irq(master->irq, master); kfree(master); } return clk; } static const struct clk_master_layout at91rm9200_master_layout = { .mask = 0x31F, .pres_shift = 2, }; static const struct clk_master_layout at91sam9x5_master_layout = { .mask = 0x373, .pres_shift = 4, }; static struct clk_master_characteristics * __init of_at91_clk_master_get_characteristics(struct device_node *np) { struct clk_master_characteristics *characteristics; characteristics = kzalloc(sizeof(*characteristics), GFP_KERNEL); if (!characteristics) return NULL; if (of_at91_get_clk_range(np, "atmel,clk-output-range", &characteristics->output)) goto out_free_characteristics; of_property_read_u32_array(np, "atmel,clk-divisors", characteristics->divisors, 4); characteristics->have_div3_pres = of_property_read_bool(np, "atmel,master-clk-have-div3-pres"); return characteristics; out_free_characteristics: kfree(characteristics); return NULL; } static void __init of_at91_clk_master_setup(struct device_node *np, struct at91_pmc *pmc, const struct clk_master_layout *layout) { struct clk *clk; int num_parents; unsigned int irq; const char *parent_names[MASTER_SOURCE_MAX]; const char *name = np->name; struct clk_master_characteristics *characteristics; num_parents = of_clk_get_parent_count(np); if (num_parents <= 0 || num_parents > MASTER_SOURCE_MAX) return; of_clk_parent_fill(np, parent_names, num_parents); of_property_read_string(np, "clock-output-names", &name); characteristics = of_at91_clk_master_get_characteristics(np); if (!characteristics) return; irq = irq_of_parse_and_map(np, 0); if (!irq) goto out_free_characteristics; clk = at91_clk_register_master(pmc, irq, name, num_parents, parent_names, layout, characteristics); if (IS_ERR(clk)) goto out_free_characteristics; of_clk_add_provider(np, of_clk_src_simple_get, clk); return; out_free_characteristics: kfree(characteristics); } void __init of_at91rm9200_clk_master_setup(struct device_node *np, struct at91_pmc *pmc) { of_at91_clk_master_setup(np, pmc, &at91rm9200_master_layout); } void __init of_at91sam9x5_clk_master_setup(struct device_node *np, struct at91_pmc *pmc) { of_at91_clk_master_setup(np, pmc, &at91sam9x5_master_layout); }