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Commit e7590308 authored by Stephen Boyd's avatar Stephen Boyd
Browse files

Merge tag 'sunxi-clk-fixes-for-4.11-2-bis' of... 

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
parents daffad21 372fa101

drivers/clk/sunxi-ng/Kconfig

+2 −0
Original line number Diff line number Diff line 
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

drivers/clk/sunxi-ng/ccu-sun8i-a33.c

+11 −0
Original line number Diff line number Diff line
@@ -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);

}

drivers/clk/sunxi-ng/ccu_common.c

+49 −0
Original line number Diff line number Diff line
@@ -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)

{

drivers/clk/sunxi-ng/ccu_common.h

+12 −0
Original line number Diff line number Diff line
@@ -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);