diff options
author | Stephen Boyd <sboyd@codeaurora.org> | 2017-04-17 11:04:12 -0700 |
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committer | Stephen Boyd <sboyd@codeaurora.org> | 2017-04-17 11:04:12 -0700 |
commit | e7590308d17e578e47f298cc3fec359108341cb6 (patch) | |
tree | 79c117415771dad54e79f8422fe84193f5c1c9be /drivers | |
parent | daffad2123fc3efcc2c70bd6e905960a31886556 (diff) | |
parent | 372fa10172a2f9e1bfbc70778449628e82b72341 (diff) |
Merge tag 'sunxi-clk-fixes-for-4.11-2-bis' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into clk-fixes
Pull Allwinner clock fixes for 4.11 from Maxime Ripard:
Two build errors fixes for the sunxi-ng drivers.
The two other patches fix random CPU crashes happening on the A33 since
CPUFreq has been enabled in 4.11.
* tag 'sunxi-clk-fixes-for-4.11-2-bis' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/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
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/clk/sunxi-ng/Kconfig | 2 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu-sun8i-a33.c | 11 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_common.c | 49 | ||||
-rw-r--r-- | drivers/clk/sunxi-ng/ccu_common.h | 12 |
4 files changed, 74 insertions, 0 deletions
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); |