--- /dev/null
+/*
+ * Marvell MVEBU CPU clock handling.
+ *
+ * Copyright (C) 2012 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/mvebu-pmsu.h>
+#include <asm/smp_plat.h>
+
+#define SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET 0x0
+#define SYS_CTRL_CLK_DIVIDER_CTRL_RESET_ALL 0xff
+#define SYS_CTRL_CLK_DIVIDER_CTRL_RESET_SHIFT 8
+#define SYS_CTRL_CLK_DIVIDER_CTRL2_OFFSET 0x8
+#define SYS_CTRL_CLK_DIVIDER_CTRL2_NBCLK_RATIO_SHIFT 16
+#define SYS_CTRL_CLK_DIVIDER_VALUE_OFFSET 0xC
+#define SYS_CTRL_CLK_DIVIDER_MASK 0x3F
+
+#define PMU_DFS_RATIO_SHIFT 16
+#define PMU_DFS_RATIO_MASK 0x3F
+
+#define MAX_CPU 4
+struct cpu_clk {
+ struct clk_hw hw;
+ int cpu;
+ const char *clk_name;
+ const char *parent_name;
+ void __iomem *reg_base;
+ void __iomem *pmu_dfs;
+};
+
+static struct clk **clks;
+
+static struct clk_onecell_data clk_data;
+
+#define to_cpu_clk(p) container_of(p, struct cpu_clk, hw)
+
+static unsigned long clk_cpu_recalc_rate(struct clk_hw *hwclk,
+ unsigned long parent_rate)
+{
+ struct cpu_clk *cpuclk = to_cpu_clk(hwclk);
+ u32 reg, div;
+
+ reg = readl(cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_VALUE_OFFSET);
+ div = (reg >> (cpuclk->cpu * 8)) & SYS_CTRL_CLK_DIVIDER_MASK;
+ return parent_rate / div;
+}
+
+static long clk_cpu_round_rate(struct clk_hw *hwclk, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ /* Valid ratio are 1:1, 1:2 and 1:3 */
+ u32 div;
+
+ div = *parent_rate / rate;
+ if (div == 0)
+ div = 1;
+ else if (div > 3)
+ div = 3;
+
+ return *parent_rate / div;
+}
+
+static int clk_cpu_off_set_rate(struct clk_hw *hwclk, unsigned long rate,
+ unsigned long parent_rate)
+
+{
+ struct cpu_clk *cpuclk = to_cpu_clk(hwclk);
+ u32 reg, div;
+ u32 reload_mask;
+
+ div = parent_rate / rate;
+ reg = (readl(cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_VALUE_OFFSET)
+ & (~(SYS_CTRL_CLK_DIVIDER_MASK << (cpuclk->cpu * 8))))
+ | (div << (cpuclk->cpu * 8));
+ writel(reg, cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_VALUE_OFFSET);
+ /* Set clock divider reload smooth bit mask */
+ reload_mask = 1 << (20 + cpuclk->cpu);
+
+ reg = readl(cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET)
+ | reload_mask;
+ writel(reg, cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET);
+
+ /* Now trigger the clock update */
+ reg = readl(cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET)
+ | 1 << 24;
+ writel(reg, cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET);
+
+ /* Wait for clocks to settle down then clear reload request */
+ udelay(1000);
+ reg &= ~(reload_mask | 1 << 24);
+ writel(reg, cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET);
+ udelay(1000);
+
+ return 0;
+}
+
+static int clk_cpu_on_set_rate(struct clk_hw *hwclk, unsigned long rate,
+ unsigned long parent_rate)
+{
+ u32 reg;
+ unsigned long fabric_div, target_div, cur_rate;
+ struct cpu_clk *cpuclk = to_cpu_clk(hwclk);
+
+ /*
+ * PMU DFS registers are not mapped, Device Tree does not
+ * describes them. We cannot change the frequency dynamically.
+ */
+ if (!cpuclk->pmu_dfs)
+ return -ENODEV;
+
+ cur_rate = __clk_get_rate(hwclk->clk);
+
+ reg = readl(cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL2_OFFSET);
+ fabric_div = (reg >> SYS_CTRL_CLK_DIVIDER_CTRL2_NBCLK_RATIO_SHIFT) &
+ SYS_CTRL_CLK_DIVIDER_MASK;
+
+ /* Frequency is going up */
+ if (rate == 2 * cur_rate)
+ target_div = fabric_div / 2;
+ /* Frequency is going down */
+ else
+ target_div = fabric_div;
+
+ if (target_div == 0)
+ target_div = 1;
+
+ reg = readl(cpuclk->pmu_dfs);
+ reg &= ~(PMU_DFS_RATIO_MASK << PMU_DFS_RATIO_SHIFT);
+ reg |= (target_div << PMU_DFS_RATIO_SHIFT);
+ writel(reg, cpuclk->pmu_dfs);
+
+ reg = readl(cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET);
+ reg |= (SYS_CTRL_CLK_DIVIDER_CTRL_RESET_ALL <<
+ SYS_CTRL_CLK_DIVIDER_CTRL_RESET_SHIFT);
+ writel(reg, cpuclk->reg_base + SYS_CTRL_CLK_DIVIDER_CTRL_OFFSET);
+
+ return mvebu_pmsu_dfs_request(cpuclk->cpu);
+}
+
+static int clk_cpu_set_rate(struct clk_hw *hwclk, unsigned long rate,
+ unsigned long parent_rate)
+{
+ if (__clk_is_enabled(hwclk->clk))
+ return clk_cpu_on_set_rate(hwclk, rate, parent_rate);
+ else
+ return clk_cpu_off_set_rate(hwclk, rate, parent_rate);
+}
+
+static const struct clk_ops cpu_ops = {
+ .recalc_rate = clk_cpu_recalc_rate,
+ .round_rate = clk_cpu_round_rate,
+ .set_rate = clk_cpu_set_rate,
+};
+
+static void __init of_cpu_clk_setup(struct device_node *node)
+{
+ struct cpu_clk *cpuclk;
+ void __iomem *clock_complex_base = of_iomap(node, 0);
+ void __iomem *pmu_dfs_base = of_iomap(node, 1);
+ int ncpus = 0;
+ struct device_node *dn;
+
+ if (clock_complex_base == NULL) {
+ pr_err("%s: clock-complex base register not set\n",
+ __func__);
+ return;
+ }
+
+ if (pmu_dfs_base == NULL)
+ pr_warn("%s: pmu-dfs base register not set, dynamic frequency scaling not available\n",
+ __func__);
+
+ for_each_node_by_type(dn, "cpu")
+ ncpus++;
+
+ cpuclk = kzalloc(ncpus * sizeof(*cpuclk), GFP_KERNEL);
+ if (WARN_ON(!cpuclk))
+ goto cpuclk_out;
+
+ clks = kzalloc(ncpus * sizeof(*clks), GFP_KERNEL);
+ if (WARN_ON(!clks))
+ goto clks_out;
+
+ for_each_node_by_type(dn, "cpu") {
+ struct clk_init_data init;
+ struct clk *clk;
+ struct clk *parent_clk;
+ char *clk_name = kzalloc(5, GFP_KERNEL);
+ int cpu, err;
+
+ if (WARN_ON(!clk_name))
+ goto bail_out;
+
+ err = of_property_read_u32(dn, "reg", &cpu);
+ if (WARN_ON(err))
+ goto bail_out;
+
+ sprintf(clk_name, "cpu%d", cpu);
+ parent_clk = of_clk_get(node, 0);
+
+ cpuclk[cpu].parent_name = __clk_get_name(parent_clk);
+ cpuclk[cpu].clk_name = clk_name;
+ cpuclk[cpu].cpu = cpu;
+ cpuclk[cpu].reg_base = clock_complex_base;
+ if (pmu_dfs_base)
+ cpuclk[cpu].pmu_dfs = pmu_dfs_base + 4 * cpu;
+ cpuclk[cpu].hw.init = &init;
+
+ init.name = cpuclk[cpu].clk_name;
+ init.ops = &cpu_ops;
+ init.flags = 0;
+ init.parent_names = &cpuclk[cpu].parent_name;
+ init.num_parents = 1;
+
+ clk = clk_register(NULL, &cpuclk[cpu].hw);
+ if (WARN_ON(IS_ERR(clk)))
+ goto bail_out;
+ clks[cpu] = clk;
+ }
+ clk_data.clk_num = MAX_CPU;
+ clk_data.clks = clks;
+ of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
+
+ return;
+bail_out:
+ kfree(clks);
+ while(ncpus--)
+ kfree(cpuclk[ncpus].clk_name);
+clks_out:
+ kfree(cpuclk);
+cpuclk_out:
+ iounmap(clock_complex_base);
+}
+
+CLK_OF_DECLARE(armada_xp_cpu_clock, "marvell,armada-xp-cpu-clock",
+ of_cpu_clk_setup);
Code Review / kvmfornfv.git / blobdiff