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Commit b3b02eac authored by Alexandre Belloni's avatar Alexandre Belloni Committed by Stephen Boyd
Browse files

clk: at91: Add sama5d2 suspend/resume 



On sama5d2, VDD core maybe be cut while in suspend. This means registers
will be lost. Ensure they are saved and restored properly.

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 682430e8

drivers/clk/at91/clk-generated.c

+2 −0
Original line number Diff line number Diff line
@@ -266,6 +266,8 @@ at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock, 
	if (ret) {

		kfree(gck);

		hw = ERR_PTR(ret);

	} else {

		pmc_register_id(id);

	}



	return hw;

drivers/clk/at91/clk-peripheral.c

+3 −1
Original line number Diff line number Diff line
@@ -367,8 +367,10 @@ at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock, 
	if (ret) {

		kfree(periph);

		hw = ERR_PTR(ret);

	} else

	} else {

		clk_sam9x5_peripheral_autodiv(periph);

		pmc_register_id(id);

	}



	return hw;

}

drivers/clk/at91/pmc.c

+129 −0
Original line number Diff line number Diff line
@@ -13,12 +13,16 @@ 
#include <linux/clk/at91_pmc.h>

#include <linux/of.h>

#include <linux/mfd/syscon.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/syscore_ops.h>



#include <asm/proc-fns.h>



#include "pmc.h"



#define PMC_MAX_IDS 128



int of_at91_get_clk_range(struct device_node *np, const char *propname,

			  struct clk_range *range)

{
@@ -41,3 +45,128 @@ int of_at91_get_clk_range(struct device_node *np, const char *propname, 
	return 0;

}

EXPORT_SYMBOL_GPL(of_at91_get_clk_range);



#ifdef CONFIG_PM

static struct regmap *pmcreg;



static u8 registered_ids[PMC_MAX_IDS];



static struct

{

	u32 scsr;

	u32 pcsr0;

	u32 uckr;

	u32 mor;

	u32 mcfr;

	u32 pllar;

	u32 mckr;

	u32 usb;

	u32 imr;

	u32 pcsr1;

	u32 pcr[PMC_MAX_IDS];

	u32 audio_pll0;

	u32 audio_pll1;

} pmc_cache;



void pmc_register_id(u8 id)

{

	int i;



	for (i = 0; i < PMC_MAX_IDS; i++) {

		if (registered_ids[i] == 0) {

			registered_ids[i] = id;

			break;

		}

		if (registered_ids[i] == id)

			break;

	}

}



static int pmc_suspend(void)

{

	int i;



	regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.scsr);

	regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0);

	regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr);

	regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor);

	regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr);

	regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar);

	regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr);

	regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb);

	regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr);

	regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1);



	for (i = 0; registered_ids[i]; i++) {

		regmap_write(pmcreg, AT91_PMC_PCR,

			     (registered_ids[i] & AT91_PMC_PCR_PID_MASK));

		regmap_read(pmcreg, AT91_PMC_PCR,

			    &pmc_cache.pcr[registered_ids[i]]);

	}



	return 0;

}



static void pmc_resume(void)

{

	int i, ret = 0;

	u32 tmp;



	regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);

	if (pmc_cache.mckr != tmp)

		pr_warn("MCKR was not configured properly by the firmware\n");

	regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp);

	if (pmc_cache.pllar != tmp)

		pr_warn("PLLAR was not configured properly by the firmware\n");



	regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.scsr);

	regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0);

	regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr);

	regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor);

	regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr);

	regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb);

	regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr);

	regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1);



	for (i = 0; registered_ids[i]; i++) {

		regmap_write(pmcreg, AT91_PMC_PCR,

			     pmc_cache.pcr[registered_ids[i]] |

			     AT91_PMC_PCR_CMD);

	}



	if (pmc_cache.uckr & AT91_PMC_UPLLEN) {

		ret = regmap_read_poll_timeout(pmcreg, AT91_PMC_SR, tmp,

					       !(tmp & AT91_PMC_LOCKU),

					       10, 5000);

		if (ret)

			pr_crit("USB PLL didn't lock when resuming\n");

	}

}



static struct syscore_ops pmc_syscore_ops = {

	.suspend = pmc_suspend,

	.resume = pmc_resume,

};



static const struct of_device_id sama5d2_pmc_dt_ids[] = {

	{ .compatible = "atmel,sama5d2-pmc" },

	{ /* sentinel */ }

};



static int __init pmc_register_ops(void)

{

	struct device_node *np;



	np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);



	pmcreg = syscon_node_to_regmap(np);

	if (IS_ERR(pmcreg))

		return PTR_ERR(pmcreg);



	register_syscore_ops(&pmc_syscore_ops);



	return 0;

}

/* This has to happen before arch_initcall because of the tcb_clksrc driver */

postcore_initcall(pmc_register_ops);

#endif

drivers/clk/at91/pmc.h

+6 −0
Original line number Diff line number Diff line
@@ -29,4 +29,10 @@ struct clk_range { 
int of_at91_get_clk_range(struct device_node *np, const char *propname,

			  struct clk_range *range);



#ifdef CONFIG_PM

void pmc_register_id(u8 id);

#else

static inline void pmc_register_id(u8 id) {}

#endif



#endif /* __PMC_H_ */