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path: root/drivers/clk/mvebu/clk-cpu.c
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Diffstat (limited to 'drivers/clk/mvebu/clk-cpu.c')
-rw-r--r--drivers/clk/mvebu/clk-cpu.c133
1 files changed, 102 insertions, 31 deletions
diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
index b0fbc0715491..0de7660e73d2 100644
--- a/drivers/clk/mvebu/clk-cpu.c
+++ b/drivers/clk/mvebu/clk-cpu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* Marvell MVEBU CPU clock handling.
*
@@ -5,21 +6,28 @@
*
* 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/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_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 +36,7 @@ struct cpu_clk {
const char *clk_name;
const char *parent_name;
void __iomem *reg_base;
+ void __iomem *pmu_dfs;
};
static struct clk **clks;
@@ -47,23 +56,26 @@ static unsigned long clk_cpu_recalc_rate(struct clk_hw *hwclk,
return parent_rate / div;
}
-static long clk_cpu_round_rate(struct clk_hw *hwclk, unsigned long rate,
- unsigned long *parent_rate)
+static int clk_cpu_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
{
/* Valid ratio are 1:1, 1:2 and 1:3 */
u32 div;
- div = *parent_rate / rate;
+ div = req->best_parent_rate / req->rate;
if (div == 0)
div = 1;
else if (div > 3)
div = 3;
- return *parent_rate / div;
+ req->rate = req->best_parent_rate / div;
+
+ return 0;
}
-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;
@@ -95,18 +107,71 @@ 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_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,
+ .determine_rate = clk_cpu_determine_rate,
.set_rate = clk_cpu_set_rate,
};
-void __init of_cpu_clk_setup(struct device_node *node)
+static void __init of_cpu_clk_setup(struct device_node *node)
{
struct cpu_clk *cpuclk;
void __iomem *clock_complex_base = of_iomap(node, 0);
- int ncpus = 0;
- struct device_node *dn;
+ void __iomem *pmu_dfs_base = of_iomap(node, 1);
+ int ncpus = num_possible_cpus();
+ int cpu;
if (clock_complex_base == NULL) {
pr_err("%s: clock-complex base register not set\n",
@@ -114,38 +179,34 @@ void __init of_cpu_clk_setup(struct device_node *node)
return;
}
- for_each_node_by_type(dn, "cpu")
- ncpus++;
+ if (pmu_dfs_base == NULL)
+ pr_warn("%s: pmu-dfs base register not set, dynamic frequency scaling not available\n",
+ __func__);
- cpuclk = kzalloc(ncpus * sizeof(*cpuclk), GFP_KERNEL);
+ cpuclk = kcalloc(ncpus, sizeof(*cpuclk), GFP_KERNEL);
if (WARN_ON(!cpuclk))
- return;
+ goto cpuclk_out;
- clks = kzalloc(ncpus * sizeof(*clks), GFP_KERNEL);
+ clks = kcalloc(ncpus, sizeof(*clks), GFP_KERNEL);
if (WARN_ON(!clks))
goto clks_out;
- for_each_node_by_type(dn, "cpu") {
+ for_each_possible_cpu(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].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;
@@ -170,7 +231,17 @@ bail_out:
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);
generated by cgit (git 2.34.1) at 2025-12-25 14:28:55 +0000