Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-04-19 17:16:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-04-19 17:16:18 -0700
commitf61143c45077df4fa78e2f1ba455a00bbe1d5b8c (patch)
tree3dc9bbd23deacbf21b70e742f75d54f1f496c8e9
parent4988f7a40f45929588d4b8f09c71eb785f55a19c (diff)
parente7590308d17e578e47f298cc3fec359108341cb6 (diff)
Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fixes from Stephen Boyd" - one stm32f4 fix for a change that introduced the PLL_I2S and PLL_SAI boards - two Allwinner clk driver build fixes - two Allwinner CPU clk driver fixes where we see random CPUFreq crashes because the CPU's PLL locks up sometimes when we change the rate * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux: clk: sunxi-ng: a33: gate then ungate PLL CPU clk after rate change clk: sunxi-ng: Add clk notifier to gate then ungate PLL clocks clk: sunxi-ng: fix build failure in ccu-sun9i-a80 driver clk: sunxi-ng: fix build error without CONFIG_RESET_CONTROLLER clk: stm32f4: fix: exclude values 0 and 1 for PLLQ
-rw-r--r--drivers/clk/clk-stm32f4.c13
-rw-r--r--drivers/clk/sunxi-ng/Kconfig2
-rw-r--r--drivers/clk/sunxi-ng/ccu-sun8i-a33.c11
-rw-r--r--drivers/clk/sunxi-ng/ccu_common.c49
-rw-r--r--drivers/clk/sunxi-ng/ccu_common.h12
5 files changed, 84 insertions, 3 deletions
diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
index ab609a76706f..cf9449b3dbd9 100644
--- a/drivers/clk/clk-stm32f4.c
+++ b/drivers/clk/clk-stm32f4.c
@@ -429,6 +429,13 @@ static const struct clk_div_table pll_divp_table[] = {
{ 0, 2 }, { 1, 4 }, { 2, 6 }, { 3, 8 }, { 0 }
};
+static const struct clk_div_table pll_divq_table[] = {
+ { 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 }, { 7, 7 },
+ { 8, 8 }, { 9, 9 }, { 10, 10 }, { 11, 11 }, { 12, 12 }, { 13, 13 },
+ { 14, 14 }, { 15, 15 },
+ { 0 }
+};
+
static const struct clk_div_table pll_divr_table[] = {
{ 2, 2 }, { 3, 3 }, { 4, 4 }, { 5, 5 }, { 6, 6 }, { 7, 7 }, { 0 }
};
@@ -496,9 +503,9 @@ struct stm32f4_div_data {
#define MAX_PLL_DIV 3
static const struct stm32f4_div_data div_data[MAX_PLL_DIV] = {
- { 16, 2, 0, pll_divp_table },
- { 24, 4, CLK_DIVIDER_ONE_BASED, NULL },
- { 28, 3, 0, pll_divr_table },
+ { 16, 2, 0, pll_divp_table },
+ { 24, 4, 0, pll_divq_table },
+ { 28, 3, 0, pll_divr_table },
};
struct stm32f4_pll_data {
diff --git a/drivers/clk/sunxi-ng/Kconfig b/drivers/clk/sunxi-ng/Kconfig
index 72109d2cf41b..1c2357301017 100644
--- a/drivers/clk/sunxi-ng/Kconfig
+++ b/drivers/clk/sunxi-ng/Kconfig
@@ -1,6 +1,7 @@
config SUNXI_CCU
bool "Clock support for Allwinner SoCs"
depends on ARCH_SUNXI || COMPILE_TEST
+ select RESET_CONTROLLER
default ARCH_SUNXI
if SUNXI_CCU
@@ -135,6 +136,7 @@ config SUN8I_V3S_CCU
config SUN9I_A80_CCU
bool "Support for the Allwinner A80 CCU"
select SUNXI_CCU_DIV
+ select SUNXI_CCU_MULT
select SUNXI_CCU_GATE
select SUNXI_CCU_NKMP
select SUNXI_CCU_NM
diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c
index a7b3c08ed0e2..2c69b631967a 100644
--- a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c
+++ b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c
@@ -752,6 +752,13 @@ static const struct sunxi_ccu_desc sun8i_a33_ccu_desc = {
.num_resets = ARRAY_SIZE(sun8i_a33_ccu_resets),
};
+static struct ccu_pll_nb sun8i_a33_pll_cpu_nb = {
+ .common = &pll_cpux_clk.common,
+ /* copy from pll_cpux_clk */
+ .enable = BIT(31),
+ .lock = BIT(28),
+};
+
static struct ccu_mux_nb sun8i_a33_cpu_nb = {
.common = &cpux_clk.common,
.cm = &cpux_clk.mux,
@@ -783,6 +790,10 @@ static void __init sun8i_a33_ccu_setup(struct device_node *node)
sunxi_ccu_probe(node, reg, &sun8i_a33_ccu_desc);
+ /* Gate then ungate PLL CPU after any rate changes */
+ ccu_pll_notifier_register(&sun8i_a33_pll_cpu_nb);
+
+ /* Reparent CPU during PLL CPU rate changes */
ccu_mux_notifier_register(pll_cpux_clk.common.hw.clk,
&sun8i_a33_cpu_nb);
}
diff --git a/drivers/clk/sunxi-ng/ccu_common.c b/drivers/clk/sunxi-ng/ccu_common.c
index 8a47bafd7890..9d8724715a43 100644
--- a/drivers/clk/sunxi-ng/ccu_common.c
+++ b/drivers/clk/sunxi-ng/ccu_common.c
@@ -14,11 +14,13 @@
* GNU General Public License for more details.
*/
+#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
#include "ccu_common.h"
+#include "ccu_gate.h"
#include "ccu_reset.h"
static DEFINE_SPINLOCK(ccu_lock);
@@ -39,6 +41,53 @@ void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock)
WARN_ON(readl_relaxed_poll_timeout(addr, reg, reg & lock, 100, 70000));
}
+/*
+ * This clock notifier is called when the frequency of a PLL clock is
+ * changed. In common PLL designs, changes to the dividers take effect
+ * almost immediately, while changes to the multipliers (implemented
+ * as dividers in the feedback loop) take a few cycles to work into
+ * the feedback loop for the PLL to stablize.
+ *
+ * Sometimes when the PLL clock rate is changed, the decrease in the
+ * divider is too much for the decrease in the multiplier to catch up.
+ * The PLL clock rate will spike, and in some cases, might lock up
+ * completely.
+ *
+ * This notifier callback will gate and then ungate the clock,
+ * effectively resetting it, so it proceeds to work. Care must be
+ * taken to reparent consumers to other temporary clocks during the
+ * rate change, and that this notifier callback must be the first
+ * to be registered.
+ */
+static int ccu_pll_notifier_cb(struct notifier_block *nb,
+ unsigned long event, void *data)
+{
+ struct ccu_pll_nb *pll = to_ccu_pll_nb(nb);
+ int ret = 0;
+
+ if (event != POST_RATE_CHANGE)
+ goto out;
+
+ ccu_gate_helper_disable(pll->common, pll->enable);
+
+ ret = ccu_gate_helper_enable(pll->common, pll->enable);
+ if (ret)
+ goto out;
+
+ ccu_helper_wait_for_lock(pll->common, pll->lock);
+
+out:
+ return notifier_from_errno(ret);
+}
+
+int ccu_pll_notifier_register(struct ccu_pll_nb *pll_nb)
+{
+ pll_nb->clk_nb.notifier_call = ccu_pll_notifier_cb;
+
+ return clk_notifier_register(pll_nb->common->hw.clk,
+ &pll_nb->clk_nb);
+}
+
int sunxi_ccu_probe(struct device_node *node, void __iomem *reg,
const struct sunxi_ccu_desc *desc)
{
diff --git a/drivers/clk/sunxi-ng/ccu_common.h b/drivers/clk/sunxi-ng/ccu_common.h
index 73d81dc58fc5..d6fdd7a789aa 100644
--- a/drivers/clk/sunxi-ng/ccu_common.h
+++ b/drivers/clk/sunxi-ng/ccu_common.h
@@ -83,6 +83,18 @@ struct sunxi_ccu_desc {
void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock);
+struct ccu_pll_nb {
+ struct notifier_block clk_nb;
+ struct ccu_common *common;
+
+ u32 enable;
+ u32 lock;
+};
+
+#define to_ccu_pll_nb(_nb) container_of(_nb, struct ccu_pll_nb, clk_nb)
+
+int ccu_pll_notifier_register(struct ccu_pll_nb *pll_nb);
+
int sunxi_ccu_probe(struct device_node *node, void __iomem *reg,
const struct sunxi_ccu_desc *desc);