/* * 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/slab.h> #include <linux/clk.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_hw_get_rate(hwclk); 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 = kcalloc(ncpus, sizeof(*cpuclk), GFP_KERNEL); if (WARN_ON(!cpuclk)) goto cpuclk_out; clks = kcalloc(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; 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); cpuclk[cpu].parent_name = of_clk_get_parent_name(node, 0); 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); static void __init of_mv98dx3236_cpu_clk_setup(struct device_node *node) { of_clk_add_provider(node, of_clk_src_simple_get, NULL); } CLK_OF_DECLARE(mv98dx3236_cpu_clock, "marvell,mv98dx3236-cpu-clock", of_mv98dx3236_cpu_clk_setup);