Le 10/05/2017 à 19:09, 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.bell...@free-electrons.com>
Very good, thanks!
Acked-by: Nicolas Ferre <nicolas.fe...@microchip.com>
> ---
> Changes in v3:
> - use regmap_read_poll_timeout to handle the USB PLL
> - fix typo
>
>
> drivers/clk/at91/pmc.c | 104
> +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 104 insertions(+)
>
> diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
> index 526df5ba042d..7fe1dc8d1829 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 +43,105 @@ 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 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 = 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) {
> + 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
>
--
Nicolas Ferre
