@@ -5,6 +5,7 @@
obj-y += clk-rockchip.o
obj-y += clk.o
obj-y += clk-pll.o
+obj-y += clk-cpu.o
obj-$(CONFIG_RESET_CONTROLLER) += softrst.o
obj-y += clk-rk3188.o
new file mode 100644
@@ -0,0 +1,329 @@
+/*
+ * Copyright (c) 2014 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@sntech.de>
+ *
+ * based on clk/samsung/clk-cpu.c
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Thomas Abraham <thomas.ab@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * A CPU clock is defined as a clock supplied to a CPU or a group of CPUs.
+ * The CPU clock is typically derived from a hierarchy of clock
+ * blocks which includes mux and divider blocks. There are a number of other
+ * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI
+ * clock for CPU domain. The rates of these auxiliary clocks are related to the
+ * CPU clock rate and this relation is usually specified in the hardware manual
+ * of the SoC or supplied after the SoC characterization.
+ *
+ * The below implementation of the CPU clock allows the rate changes of the CPU
+ * clock and the corresponding rate changes of the auxillary clocks of the CPU
+ * domain. The platform clock driver provides a clock register configuration
+ * for each configurable rate which is then used to program the clock hardware
+ * registers to acheive a fast co-oridinated rate change for all the CPU domain
+ * clocks.
+ *
+ * On a rate change request for the CPU clock, the rate change is propagated
+ * upto the PLL supplying the clock to the CPU domain clock blocks. While the
+ * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an
+ * alternate clock source. If required, the alternate clock source is divided
+ * down in order to keep the output clock rate within the previous OPP limits.
+ */
+
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/clk-provider.h>
+#include "clk.h"
+
+/**
+ * struct rockchip_cpuclk: information about clock supplied to a CPU core.
+ * @hw: handle between ccf and cpu clock.
+ * @alt_parent: alternate parent clock to use when switching the speed
+ * of the primary parent clock.
+ * @reg_base: base register for cpu-clock values.
+ * @clk_nb: clock notifier registered for changes in clock speed of the
+ * primary parent clock.
+ * @rate_count: number of rates in the rate_table
+ * @rate_table: pll-rates and their associated dividers
+ * @reg_data: cpu-specific register settings
+ * @lock: clock lock
+ */
+struct rockchip_cpuclk {
+ struct clk_hw hw;
+
+ struct clk_mux cpu_mux;
+ const struct clk_ops *cpu_mux_ops;
+
+ struct clk *alt_parent;
+ void __iomem *reg_base;
+ struct notifier_block clk_nb;
+ unsigned int rate_count;
+ struct rockchip_cpuclk_rate_table *rate_table;
+ const struct rockchip_cpuclk_reg_data *reg_data;
+ spinlock_t *lock;
+};
+
+#define to_rockchip_cpuclk_hw(hw) container_of(hw, struct rockchip_cpuclk, hw)
+#define to_rockchip_cpuclk_nb(nb) \
+ container_of(nb, struct rockchip_cpuclk, clk_nb)
+
+static const struct rockchip_cpuclk_rate_table *rockchip_get_cpuclk_settings(
+ struct rockchip_cpuclk *cpuclk, unsigned long rate)
+{
+ const struct rockchip_cpuclk_rate_table *rate_table =
+ cpuclk->rate_table;
+ int i;
+
+ for (i = 0; i < cpuclk->rate_count; i++) {
+ if (rate == rate_table[i].prate)
+ return &rate_table[i];
+ }
+
+ return NULL;
+}
+
+static unsigned long rockchip_cpuclk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_hw(hw);
+ const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
+ u32 clksel0 = readl_relaxed(cpuclk->reg_base + reg_data->core_reg);
+
+ clksel0 >>= reg_data->div_core_shift;
+ clksel0 &= reg_data->div_core_mask;
+ return parent_rate / (clksel0 + 1);
+}
+
+static const struct clk_ops rockchip_cpuclk_ops = {
+ .recalc_rate = rockchip_cpuclk_recalc_rate,
+};
+
+static void rockchip_cpuclk_set_dividers(struct rockchip_cpuclk *cpuclk,
+ const struct rockchip_cpuclk_rate_table *rate)
+{
+ int i;
+
+ /* alternate parent is active now. set the dividers */
+ for (i = 0; i < ARRAY_SIZE(rate->divs); i++) {
+ const struct rockchip_cpuclk_clksel *clksel = &rate->divs[i];
+
+ if (!clksel->reg)
+ continue;
+
+ pr_debug("%s: setting reg 0x%x to 0x%x\n",
+ __func__, clksel->reg, clksel->val);
+ writel(clksel->val , cpuclk->reg_base + clksel->reg);
+ }
+}
+
+static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
+ struct clk_notifier_data *ndata)
+{
+ const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
+ unsigned long alt_prate, alt_div;
+
+ alt_prate = clk_get_rate(cpuclk->alt_parent);
+
+ spin_lock(cpuclk->lock);
+
+ /*
+ * If the old parent clock speed is less than the clock speed
+ * of the alternate parent, then it should be ensured that at no point
+ * the armclk speed is more than the old_rate until the dividers are
+ * set.
+ */
+ if (alt_prate > ndata->old_rate) {
+ /* calculate dividers */
+ alt_div = DIV_ROUND_UP(alt_prate, ndata->old_rate) - 1;
+ if (alt_div > reg_data->div_core_mask) {
+ pr_warn("%s: limiting alt-divider %lu to %d\n",
+ __func__, alt_div, reg_data->div_core_mask);
+ alt_div = reg_data->div_core_mask;
+ }
+
+ /*
+ * Change parents and add dividers in a single transaction.
+ *
+ * NOTE: we do this in a single transaction so we're never
+ * dividing the primary parent by the extra dividers that were
+ * needed for the alt.
+ */
+ pr_debug("%s: setting div %lu as alt-rate %lu > old-rate %lu\n",
+ __func__, alt_div, alt_prate, ndata->old_rate);
+
+ writel(HIWORD_UPDATE(alt_div, reg_data->div_core_mask,
+ reg_data->div_core_shift) |
+ HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
+ cpuclk->reg_base + reg_data->core_reg);
+ } else {
+ /* select alternate parent */
+ writel(HIWORD_UPDATE(1, 1, reg_data->mux_core_shift),
+ cpuclk->reg_base + reg_data->core_reg);
+ }
+
+ spin_unlock(cpuclk->lock);
+ return 0;
+}
+
+static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
+ struct clk_notifier_data *ndata)
+{
+ const struct rockchip_cpuclk_reg_data *reg_data = cpuclk->reg_data;
+ const struct rockchip_cpuclk_rate_table *rate;
+
+ rate = rockchip_get_cpuclk_settings(cpuclk, ndata->new_rate);
+ if (!rate) {
+ pr_err("%s: Invalid rate : %lu for cpuclk\n",
+ __func__, ndata->new_rate);
+ return -EINVAL;
+ }
+
+ spin_lock(cpuclk->lock);
+
+ if (ndata->old_rate < ndata->new_rate)
+ rockchip_cpuclk_set_dividers(cpuclk, rate);
+
+ /*
+ * post-rate change event, re-mux to primary parent and remove dividers.
+ *
+ * NOTE: we do this in a single transaction so we're never dividing the
+ * primary parent by the extra dividers that were needed for the alt.
+ */
+
+ writel(HIWORD_UPDATE(0, reg_data->div_core_mask,
+ reg_data->div_core_shift) |
+ HIWORD_UPDATE(0, 1, reg_data->mux_core_shift),
+ cpuclk->reg_base + reg_data->core_reg);
+
+ if (ndata->old_rate > ndata->new_rate)
+ rockchip_cpuclk_set_dividers(cpuclk, rate);
+
+ spin_unlock(cpuclk->lock);
+ return 0;
+}
+
+/*
+ * This clock notifier is called when the frequency of the parent clock
+ * of cpuclk is to be changed. This notifier handles the setting up all
+ * the divider clocks, remux to temporary parent and handling the safe
+ * frequency levels when using temporary parent.
+ */
+static int rockchip_cpuclk_notifier_cb(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct clk_notifier_data *ndata = data;
+ struct rockchip_cpuclk *cpuclk = to_rockchip_cpuclk_nb(nb);
+ int ret = 0;
+
+ pr_debug("%s: event %lu, old_rate %lu, new_rate: %lu\n",
+ __func__, event, ndata->old_rate, ndata->new_rate);
+ if (event == PRE_RATE_CHANGE)
+ ret = rockchip_cpuclk_pre_rate_change(cpuclk, ndata);
+ else if (event == POST_RATE_CHANGE)
+ ret = rockchip_cpuclk_post_rate_change(cpuclk, ndata);
+
+ return notifier_from_errno(ret);
+}
+
+struct clk *rockchip_clk_register_cpuclk(const char *name,
+ const char **parent_names, u8 num_parents,
+ const struct rockchip_cpuclk_reg_data *reg_data,
+ const struct rockchip_cpuclk_rate_table *rates,
+ int nrates, void __iomem *reg_base, spinlock_t *lock)
+{
+ struct rockchip_cpuclk *cpuclk;
+ struct clk_init_data init;
+ struct clk *clk, *cclk;
+ int ret;
+
+ if (num_parents != 2) {
+ pr_err("%s: needs two parent clocks\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+
+ cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL);
+ if (!cpuclk)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.parent_names = &parent_names[0];
+ init.num_parents = 1;
+ init.ops = &rockchip_cpuclk_ops;
+
+ /* only allow rate changes when we have a rate table */
+ init.flags = (nrates > 0) ? CLK_SET_RATE_PARENT : 0;
+
+ /* disallow automatic parent changes by ccf */
+ init.flags |= CLK_SET_RATE_NO_REPARENT;
+
+ init.flags |= CLK_GET_RATE_NOCACHE;
+
+ cpuclk->reg_base = reg_base;
+ cpuclk->lock = lock;
+ cpuclk->reg_data = reg_data;
+ cpuclk->clk_nb.notifier_call = rockchip_cpuclk_notifier_cb;
+ cpuclk->hw.init = &init;
+
+ cpuclk->alt_parent = __clk_lookup(parent_names[1]);
+ if (!cpuclk->alt_parent) {
+ pr_err("%s: could not lookup alternate parent\n",
+ __func__);
+ ret = -EINVAL;
+ goto free_cpuclk;
+ }
+
+ ret = clk_prepare_enable(cpuclk->alt_parent);
+ if (ret) {
+ pr_err("%s: could not enable alternate parent\n",
+ __func__);
+ goto free_cpuclk;
+ }
+
+ clk = __clk_lookup(parent_names[0]);
+ if (!clk) {
+ pr_err("%s: could not lookup parent clock %s\n",
+ __func__, parent_names[0]);
+ ret = -EINVAL;
+ goto free_cpuclk;
+ }
+
+ ret = clk_notifier_register(clk, &cpuclk->clk_nb);
+ if (ret) {
+ pr_err("%s: failed to register clock notifier for %s\n",
+ __func__, name);
+ goto free_cpuclk;
+ }
+
+ if (nrates > 0) {
+ cpuclk->rate_count = nrates;
+ cpuclk->rate_table = kmemdup(rates,
+ sizeof(*rates) * nrates,
+ GFP_KERNEL);
+ if (!cpuclk->rate_table) {
+ pr_err("%s: could not allocate memory for cpuclk rates\n",
+ __func__);
+ ret = -ENOMEM;
+ goto unregister_notifier;
+ }
+ }
+
+ cclk = clk_register(NULL, &cpuclk->hw);
+ if (IS_ERR(clk)) {
+ pr_err("%s: could not register cpuclk %s\n", __func__, name);
+ ret = PTR_ERR(clk);
+ goto free_rate_table;
+ }
+
+ return cclk;
+
+free_rate_table:
+ kfree(cpuclk->rate_table);
+unregister_notifier:
+ clk_notifier_unregister(clk, &cpuclk->clk_nb);
+free_cpuclk:
+ kfree(cpuclk);
+ return ERR_PTR(ret);
+}
@@ -297,6 +297,27 @@ void __init rockchip_clk_register_branches(
}
}
+void __init rockchip_clk_register_armclk(unsigned int lookup_id,
+ const char *name, const char **parent_names,
+ u8 num_parents,
+ const struct rockchip_cpuclk_reg_data *reg_data,
+ const struct rockchip_cpuclk_rate_table *rates,
+ int nrates)
+{
+ struct clk *clk;
+
+ clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
+ reg_data, rates, nrates, reg_base,
+ &clk_lock);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s: %ld\n",
+ __func__, name, PTR_ERR(clk));
+ return;
+ }
+
+ rockchip_clk_add_lookup(clk, lookup_id);
+}
+
void __init rockchip_clk_protect_critical(const char *clocks[], int nclocks)
{
int i;
@@ -120,6 +120,38 @@ struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type,
struct rockchip_pll_rate_table *rate_table,
spinlock_t *lock);
+struct rockchip_cpuclk_clksel {
+ int reg;
+ u32 val;
+};
+
+#define ROCKCHIP_CPUCLK_NUM_DIVIDERS 2
+struct rockchip_cpuclk_rate_table {
+ unsigned long prate;
+ struct rockchip_cpuclk_clksel divs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
+};
+
+/**
+ * struct rockchip_cpuclk_reg_data: describes register offsets and masks of the cpuclock
+ * @core_reg: register offset of the core settings register
+ * @div_core_shift: core divider offset used to divide the pll value
+ * @div_core_mask: core divider mask
+ * @mux_core_shift: offset of the core multiplexer
+ */
+struct rockchip_cpuclk_reg_data {
+ int core_reg;
+ u8 div_core_shift;
+ u32 div_core_mask;
+ int mux_core_reg;
+ u8 mux_core_shift;
+};
+
+struct clk *rockchip_clk_register_cpuclk(const char *name,
+ const char **parent_names, u8 num_parents,
+ const struct rockchip_cpuclk_reg_data *reg_data,
+ const struct rockchip_cpuclk_rate_table *rates,
+ int nrates, void __iomem *reg_base, spinlock_t *lock);
+
#define PNAME(x) static const char *x[] __initconst
enum rockchip_clk_branch_type {
@@ -329,6 +361,11 @@ void rockchip_clk_register_branches(struct rockchip_clk_branch *clk_list,
unsigned int nr_clk);
void rockchip_clk_register_plls(struct rockchip_pll_clock *pll_list,
unsigned int nr_pll, int grf_lock_offset);
+void rockchip_clk_register_armclk(unsigned int lookup_id, const char *name,
+ const char **parent_names, u8 num_parents,
+ const struct rockchip_cpuclk_reg_data *reg_data,
+ const struct rockchip_cpuclk_rate_table *rates,
+ int nrates);
void rockchip_clk_protect_critical(const char *clocks[], int nclocks);
#define ROCKCHIP_SOFTRST_HIWORD_MASK BIT(0)