[v5 1/3] soc: fsl: handle RCPM errata A-008646 on SoC LS1021A

[Biwen Li]

Hi All,

1.Need apply below patches before apply these patches.
1.1 Flextimer dts
https://lore.kernel.org/patchwork/series/405653/mbox/ (https://lore.kernel.org/patchwork/patch/1112493/)
1.2 RCPM driver
https://lore.kernel.org/patchwork/patch/1143809/mbox/ [v10,1/3] PM: wakeup: Add routine to help fetch wakeup source object)
https://lore.kernel.org/patchwork/patch/1143810/mbox/ ([v10,2/3] Documentation: dt: binding: fsl: Add 'little-endian' and update Chassis define)
https://lore.kernel.org/patchwork/patch/1143811/mbox/ ([v10,3/3] soc: fsl: add RCPM driver)

> Subject: [v5 1/3] soc: fsl: handle RCPM errata A-008646 on SoC LS1021A
> 
> Description:
> 	- Reading configuration register RCPM_IPPDEXPCR1
> 	  always return zero
> 
> Workaround:
> 	- Save register RCPM_IPPDEXPCR1's value to
> 	  register SCFG_SPARECR8.(uboot's psci also
> 	  need reading value from the register SCFG_SPARECR8
> 	  to set register RCPM_IPPDEXPCR1)
> 
> Impact:
> 	- FlexTimer module will cannot wakeup system in
> 	  deep sleep on SoC LS1021A
> 
> Signed-off-by: Biwen Li <biwen.li at nxp.com>
> ---
> Change in v5:
> 	- update the patch, because of rcpm driver has updated.
> 
> Change in v4:
> 	- rename property name
> 	  fsl,ippdexpcr-alt-addr -> fsl,ippdexpcr1-alt-addr
> 
> Change in v3:
> 	- update commit message
> 	- rename property name
> 	  fsl,rcpm-scfg -> fsl,ippdexpcr-alt-addr
> 
> Change in v2:
>   	- fix stype problems
> 
>  drivers/soc/fsl/rcpm.c | 47
> ++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 45 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/soc/fsl/rcpm.c b/drivers/soc/fsl/rcpm.c index
> a093dbe6d2cb..775c618f0456 100644
> --- a/drivers/soc/fsl/rcpm.c
> +++ b/drivers/soc/fsl/rcpm.c
> @@ -6,13 +6,16 @@
>  //
>  // Author: Ran Wang <ran.wang_1 at nxp.com>
> 
> +#include <linux/acpi.h>
>  #include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
>  #include <linux/module.h>
> -#include <linux/platform_device.h>
>  #include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/slab.h>
>  #include <linux/suspend.h>
> -#include <linux/kernel.h>
> 
>  #define RCPM_WAKEUP_CELL_MAX_SIZE	7
> 
> @@ -37,6 +40,9 @@ static int rcpm_pm_prepare(struct device *dev)
>  	struct device_node	*np = dev->of_node;
>  	u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
>  	u32 setting[RCPM_WAKEUP_CELL_MAX_SIZE] = {0};
> +	struct regmap *scfg_addr_regmap = NULL;
> +	u32 reg_offset[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
> +	u32 reg_value = 0;
> 
>  	rcpm = dev_get_drvdata(dev);
>  	if (!rcpm)
> @@ -90,6 +96,43 @@ 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 (device_property_present(dev, "fsl,ippdexpcr1-alt-addr")) {
> +			if (dev_of_node(dev)) {
> +				scfg_addr_regmap =
> syscon_regmap_lookup_by_phandle(np,
> +
> "fsl,ippdexpcr1-alt-addr");
> +			} else if (is_acpi_node(dev->fwnode)) {
> +				dev_err(dev, "not support acpi for rcpm\n");
> +				continue;
> +			}
> +
> +			if (scfg_addr_regmap && (i == 1)) {
> +				if (device_property_read_u32_array(dev,
> +				    "fsl,ippdexpcr1-alt-addr",
> +				    reg_offset,
> +				    1 + sizeof(u64)/sizeof(u32))) {
> +					scfg_addr_regmap = NULL;
> +					continue;
> +				}
> +				/* Read value from register SCFG_SPARECR8 */
> +				regmap_read(scfg_addr_regmap,
> +					    (u32)(((u64)(reg_offset[1] << (sizeof(u32) * 8) |
> +					    reg_offset[2])) & 0xffffffff),
> +					    &reg_value);
> +				/* Write value to register SCFG_SPARECR8 */
> +				regmap_write(scfg_addr_regmap,
> +					     (u32)(((u64)(reg_offset[1] << (sizeof(u32) * 8) |
> +					     reg_offset[2])) & 0xffffffff),
> +					     tmp | reg_value);
> +			}
> +		}
>  	}
> 
>  	return 0;
> --
> 2.17.1