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-rw-r--r--drivers/clk/mvebu/clk-cpu.c80
1 files changed, 75 insertions, 5 deletions
diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
index 8ebf757d29e2..3821a88077ea 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;