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Message-ID: <3e8f6251-a1d0-a342-d02a-2df249e0b220@microchip.com>
Date: Mon, 19 Jun 2017 17:45:11 +0200
From: Nicolas Ferre <nicolas.ferre@...rochip.com>
To: Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
Boris Brezillon <boris.brezillon@...e-electrons.com>,
Stephen Boyd <sboyd@...eaurora.org>
CC: <linux-clk@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v5] clk: at91: Add sama5d2 suspend/resume
Le 08/06/2017 à 02:36, Alexandre Belloni a écrit :
> 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: Alexandre Belloni <alexandre.belloni@...e-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@...rochip.com>
> ---
> Changes in v5:
> - rebased on clk-next
> - moved pmc_register_id under CONFIG_PM
>
>
> drivers/clk/at91/clk-generated.c | 2 +
> drivers/clk/at91/clk-peripheral.c | 4 +-
> drivers/clk/at91/pmc.c | 129 ++++++++++++++++++++++++++++++++++++++
> drivers/clk/at91/pmc.h | 6 ++
> 4 files changed, 140 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c
> index 07c8f701e51c..f0b7ae904ce2 100644
> --- a/drivers/clk/at91/clk-generated.c
> +++ b/drivers/clk/at91/clk-generated.c
> @@ -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;
> diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c
> index dc29fd979d3f..770118369230 100644
> --- a/drivers/clk/at91/clk-peripheral.c
> +++ b/drivers/clk/at91/clk-peripheral.c
> @@ -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;
> }
> diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
> index 526df5ba042d..775af473fe11 100644
> --- a/drivers/clk/at91/pmc.c
> +++ b/drivers/clk/at91/pmc.c
> @@ -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
> diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
> index 5771fff0ee3f..858e8ef7e8db 100644
> --- a/drivers/clk/at91/pmc.h
> +++ b/drivers/clk/at91/pmc.h
> @@ -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_ */
>
--
Nicolas Ferre
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