diff options
Diffstat (limited to 'drivers/clk/mvebu/clk-cpu.c')
| -rw-r--r-- | drivers/clk/mvebu/clk-cpu.c | 80 |
1 files changed, 75 insertions, 5 deletions
diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c index 8ebf757d29e..3821a88077e 100644 --- a/drivers/clk/mvebu/clk-cpu.c +++ b/drivers/clk/mvebu/clk-cpu.c @@ -16,10 +16,19 @@ #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_VALUE_OFFSET 0xC -#define SYS_CTRL_CLK_DIVIDER_MASK 0x3F +#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 { @@ -28,6 +37,7 @@ struct cpu_clk { const char *clk_name; const char *parent_name; void __iomem *reg_base; + void __iomem *pmu_dfs; }; static struct clk **clks; @@ -62,8 +72,9 @@ static long clk_cpu_round_rate(struct clk_hw *hwclk, unsigned long rate, return *parent_rate / div; } -static int clk_cpu_set_rate(struct clk_hw *hwclk, unsigned long rate, - unsigned long parent_rate) +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; @@ -95,6 +106,58 @@ static int clk_cpu_set_rate(struct clk_hw *hwclk, unsigned long rate, 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, @@ -105,6 +168,7 @@ 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; @@ -114,6 +178,10 @@ static void __init of_cpu_clk_setup(struct device_node *node) 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++; @@ -146,6 +214,8 @@ static void __init of_cpu_clk_setup(struct device_node *node) 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; |