* [PATCH v2] clk: at91: Add sama5d2 suspend/resume
@ 2017-04-26 11:21 Alexandre Belloni
2017-04-27 10:13 ` Nicolas Ferre
0 siblings, 1 reply; 2+ messages in thread
From: Alexandre Belloni @ 2017-04-26 11:21 UTC (permalink / raw)
To: Boris Brezillon, Stephen Boyd, Nicolas Ferre
Cc: linux-clk, linux-kernel, Alexandre Belloni
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@free-electrons.com>
---
Changes in v2:
- don't set MCKR or PLLAR and expect them to be properly set by the
firmware/bootloader.
drivers/clk/at91/pmc.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 114 insertions(+)
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index 526df5ba042d..338cd293b356 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c
@@ -13,7 +13,9 @@
#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>
@@ -41,3 +43,115 @@ 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 struct
+{
+ u32 scsr;
+ u32 pcsr0;
+ u32 uckr;
+ u32 mor;
+ u32 mcfr;
+ u32 pllar;
+ u32 mckr;
+ u32 usb;
+ u32 imr;
+ u32 pcsr1;
+ u32 pcr[64];
+} pmc_cache;
+
+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 = 2; i < 64; i++) {
+ regmap_write(pmcreg, AT91_PMC_PCR, (i & AT91_PMC_PCR_PID_MASK));
+ regmap_read(pmcreg, AT91_PMC_PCR, &pmc_cache.pcr[i]);
+ }
+
+ return 0;
+}
+
+static bool pmc_ready(unsigned int mask)
+{
+ unsigned int status;
+
+ regmap_read(pmcreg, AT91_PMC_SR, &status);
+
+ return ((status & mask) == mask) ? 1 : 0;
+}
+
+static void pmc_resume(void)
+{
+ int i;
+ unsigned int mask = 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 = 2; i < 64; i++) {
+ regmap_write(pmcreg, AT91_PMC_PCR, (i & AT91_PMC_PCR_PID_MASK));
+ regmap_write(pmcreg, AT91_PMC_PCR, pmc_cache.pcr[i]);
+ }
+
+ if (pmc_cache.uckr & AT91_PMC_UPLLEN)
+ mask |= AT91_PMC_LOCKU;
+
+ while (!pmc_ready(mask))
+ cpu_relax();
+}
+
+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 becaues of the tcb_clksrc driver */
+postcore_initcall(pmc_register_ops);
+#endif
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH v2] clk: at91: Add sama5d2 suspend/resume
2017-04-26 11:21 [PATCH v2] clk: at91: Add sama5d2 suspend/resume Alexandre Belloni
@ 2017-04-27 10:13 ` Nicolas Ferre
0 siblings, 0 replies; 2+ messages in thread
From: Nicolas Ferre @ 2017-04-27 10:13 UTC (permalink / raw)
To: Alexandre Belloni, Boris Brezillon, Stephen Boyd; +Cc: linux-clk, linux-kernel
Le 26/04/2017 à 13:21, 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@free-electrons.com>
> ---
>
> Changes in v2:
> - don't set MCKR or PLLAR and expect them to be properly set by the
> firmware/bootloader.
>
> drivers/clk/at91/pmc.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 114 insertions(+)
>
> diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
> index 526df5ba042d..338cd293b356 100644
> --- a/drivers/clk/at91/pmc.c
> +++ b/drivers/clk/at91/pmc.c
> @@ -13,7 +13,9 @@
> #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>
>
> @@ -41,3 +43,115 @@ 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 struct
> +{
> + u32 scsr;
> + u32 pcsr0;
> + u32 uckr;
> + u32 mor;
> + u32 mcfr;
> + u32 pllar;
> + u32 mckr;
> + u32 usb;
> + u32 imr;
> + u32 pcsr1;
> + u32 pcr[64];
> +} pmc_cache;
> +
> +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 = 2; i < 64; i++) {
> + regmap_write(pmcreg, AT91_PMC_PCR, (i & AT91_PMC_PCR_PID_MASK));
> + regmap_read(pmcreg, AT91_PMC_PCR, &pmc_cache.pcr[i]);
> + }
> +
> + return 0;
> +}
> +
> +static bool pmc_ready(unsigned int mask)
> +{
> + unsigned int status;
> +
> + regmap_read(pmcreg, AT91_PMC_SR, &status);
> +
> + return ((status & mask) == mask) ? 1 : 0;
> +}
> +
> +static void pmc_resume(void)
> +{
> + int i;
> + unsigned int mask = 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 = 2; i < 64; i++) {
> + regmap_write(pmcreg, AT91_PMC_PCR, (i & AT91_PMC_PCR_PID_MASK));
> + regmap_write(pmcreg, AT91_PMC_PCR, pmc_cache.pcr[i]);
> + }
> +
> + if (pmc_cache.uckr & AT91_PMC_UPLLEN)
> + mask |= AT91_PMC_LOCKU;
I understand the use of mask to be generic... but this one ^ is now the
only one used: we can simplify (and even remove the use of a function).
> +
> + while (!pmc_ready(mask))
> + cpu_relax();
I would prefer to have a timeout + printk(KERN_CRIT ...) here
> +}
> +
> +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 becaues of the tcb_clksrc driver */
NIT: typo ^ (because)
> +postcore_initcall(pmc_register_ops);
> +#endif
>
--
Nicolas Ferre
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-04-26 11:21 [PATCH v2] clk: at91: Add sama5d2 suspend/resume Alexandre Belloni
2017-04-27 10:13 ` Nicolas Ferre
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