On Mon, Nov 2, 2020 at 1:37 AM Ran Wang <ran.wang_1@xxxxxxx> wrote:
>
> From: Biwen Li <biwen.li@xxxxxxx>
>
> Hardware issue:
> - Reading register RCPM_IPPDEXPCR1 always return zero, this causes
> system firmware could not get correct information and wrongly do
> clock gating for all wakeup source IP during system suspend. Then
> those IPs will never get chance to wake system.
>
> Workaround:
> - Copy register RCPM_IPPDEXPCR1's setting to register SCFG_SPARECR8
> to allow system firmware's psci method read it and do things accordingly.
>
> Signed-off-by: Biwen Li <biwen.li@xxxxxxx>
> Signed-off-by: Ran Wang <ran.wang_1@xxxxxxx>
Applied for next. Thanks.
> ---
> Change in v4:
> - Replace property 'fsl,ippdexpcr1-alt-reg' with compatible checking as the
> workaround trigger condition.
>
> Change in v3:
> - Add copy_ippdexpcr1_setting(), simplize workaournd's implementation
> according to binding update.
> - Minor update on commit message.
>
> Change in v2:
> - Update commit message to be more clear.
> - Replace device_property_read_u32_array() with syscon_regmap_lookup_by_phandle_args()
> to make code simpler.
>
> drivers/soc/fsl/rcpm.c | 35 ++++++++++++++++++++++++++++++++++-
> 1 file changed, 34 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/soc/fsl/rcpm.c b/drivers/soc/fsl/rcpm.c
> index a093dbe..4ace28c 100644
> --- a/drivers/soc/fsl/rcpm.c
> +++ b/drivers/soc/fsl/rcpm.c
> @@ -2,7 +2,7 @@
> //
> // rcpm.c - Freescale QorIQ RCPM driver
> //
> -// Copyright 2019 NXP
> +// Copyright 2019-2020 NXP
> //
> // Author: Ran Wang <ran.wang_1@xxxxxxx>
>
> @@ -22,6 +22,28 @@ struct rcpm {
> bool little_endian;
> };
>
> +#define SCFG_SPARECR8 0x051c
> +
> +static void copy_ippdexpcr1_setting(u32 val)
> +{
> + struct device_node *np;
> + void __iomem *regs;
> + u32 reg_val;
> +
> + np = of_find_compatible_node(NULL, NULL, "fsl,ls1021a-scfg");
> + if (!np)
> + return;
> +
> + regs = of_iomap(np, 0);
> + if (!regs)
> + return;
> +
> + reg_val = ioread32be(regs + SCFG_SPARECR8);
> + iowrite32be(val | reg_val, regs + SCFG_SPARECR8);
> +
> + iounmap(regs);
> +}
> +
> /**
> * rcpm_pm_prepare - performs device-level tasks associated with power
> * management, such as programming related to the wakeup source control.
> @@ -90,6 +112,17 @@ static int rcpm_pm_prepare(struct device *dev)
> tmp |= ioread32be(address);
> iowrite32be(tmp, address);
> }
> + /*
> + * Workaround of errata A-008646 on SoC LS1021A:
> + * There is a bug of register ippdexpcr1.
> + * Reading configuration register RCPM_IPPDEXPCR1
> + * always return zero. So save ippdexpcr1's value
> + * to register SCFG_SPARECR8.And the value of
> + * ippdexpcr1 will be read from SCFG_SPARECR8.
> + */
> + if (dev_of_node(dev) && (i == 1))
> + if (of_device_is_compatible(np, "fsl,ls1021a-rcpm"))
> + copy_ippdexpcr1_setting(tmp);
> }
>
> return 0;
> --
> 2.7.4
>
