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path: root/drivers/clk/mvebu/armada-37xx-periph.c
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Diffstat (limited to 'drivers/clk/mvebu/armada-37xx-periph.c')
-rw-r--r--drivers/clk/mvebu/armada-37xx-periph.c45
1 files changed, 39 insertions, 6 deletions
diff --git a/drivers/clk/mvebu/armada-37xx-periph.c b/drivers/clk/mvebu/armada-37xx-periph.c
index b15e177bea7e..32ac6b6b7530 100644
--- a/drivers/clk/mvebu/armada-37xx-periph.c
+++ b/drivers/clk/mvebu/armada-37xx-periph.c
@@ -84,6 +84,7 @@ struct clk_pm_cpu {
void __iomem *reg_div;
u8 shift_div;
struct regmap *nb_pm_base;
+ unsigned long l1_expiration;
};
#define to_clk_double_div(_hw) container_of(_hw, struct clk_double_div, hw)
@@ -504,22 +505,52 @@ static long clk_pm_cpu_round_rate(struct clk_hw *hw, unsigned long rate,
* 2. Sleep 20ms for stabling VDD voltage
* 3. Then switch from L1 (500/600 MHz) to L0 (1000/1200 MHz).
*/
-static void clk_pm_cpu_set_rate_wa(unsigned long rate, struct regmap *base)
+static void clk_pm_cpu_set_rate_wa(struct clk_pm_cpu *pm_cpu,
+ unsigned int new_level, unsigned long rate,
+ struct regmap *base)
{
unsigned int cur_level;
- if (rate < 1000 * 1000 * 1000)
- return;
-
regmap_read(base, ARMADA_37XX_NB_CPU_LOAD, &cur_level);
cur_level &= ARMADA_37XX_NB_CPU_LOAD_MASK;
- if (cur_level <= ARMADA_37XX_DVFS_LOAD_1)
+
+ if (cur_level == new_level)
+ return;
+
+ /*
+ * System wants to go to L1 on its own. If we are going from L2/L3,
+ * remember when 20ms will expire. If from L0, set the value so that
+ * next switch to L0 won't have to wait.
+ */
+ if (new_level == ARMADA_37XX_DVFS_LOAD_1) {
+ if (cur_level == ARMADA_37XX_DVFS_LOAD_0)
+ pm_cpu->l1_expiration = jiffies;
+ else
+ pm_cpu->l1_expiration = jiffies + msecs_to_jiffies(20);
return;
+ }
+
+ /*
+ * If we are setting to L2/L3, just invalidate L1 expiration time,
+ * sleeping is not needed.
+ */
+ if (rate < 1000*1000*1000)
+ goto invalidate_l1_exp;
+
+ /*
+ * We are going to L0 with rate >= 1GHz. Check whether we have been at
+ * L1 for long enough time. If not, go to L1 for 20ms.
+ */
+ if (pm_cpu->l1_expiration && jiffies >= pm_cpu->l1_expiration)
+ goto invalidate_l1_exp;
regmap_update_bits(base, ARMADA_37XX_NB_CPU_LOAD,
ARMADA_37XX_NB_CPU_LOAD_MASK,
ARMADA_37XX_DVFS_LOAD_1);
msleep(20);
+
+invalidate_l1_exp:
+ pm_cpu->l1_expiration = 0;
}
static int clk_pm_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -553,7 +584,9 @@ static int clk_pm_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
reg = ARMADA_37XX_NB_CPU_LOAD;
mask = ARMADA_37XX_NB_CPU_LOAD_MASK;
- clk_pm_cpu_set_rate_wa(rate, base);
+ /* Apply workaround when base CPU frequency is 1000 or 1200 MHz */
+ if (parent_rate >= 1000*1000*1000)
+ clk_pm_cpu_set_rate_wa(pm_cpu, load_level, rate, base);
regmap_update_bits(base, reg, mask, load_level);