Re: [PATCH 1/3] ARM: at91: use chipid device for soc detection

Nicolas Ferre
2016-03-23T11:23:03Z

Le 18/03/2016 11:34, Alexandre Belloni a écrit :
> On 18/03/2016 at 08:21:19 +0100, Ludovic Desroches wrote :
>> So far, the CIDR and EXID registers were in the DBGU interface. This device
>> has disappeared with the SAMA5D2 family. These registers are exposed
>> through a new device called chipid.
>>
>> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
>> [nicolas.ferre@atmel.com: remove useless warnings]
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
>
>> ---
>> .../devicetree/bindings/arm/atmel-at91.txt | 4 ++
>> arch/arm/mach-at91/soc.c | 81 +++++++++++++++++-----

We may need to split this patch in 2 for going through separate arm-soc
branches: what do you think Alexandre?

Anyway, I can do it myself: no need to re-send a version:
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

We'll queue it in our upcoming at91-4.7-dt and at91-4.7-soc branches.

Bye,

>> 2 files changed, 67 insertions(+), 18 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt
>> index 7fd64ec..0b1fcbf 100644
>> --- a/Documentation/devicetree/bindings/arm/atmel-at91.txt
>> +++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt
>> @@ -41,6 +41,10 @@ compatible: must be one of:
>> - "atmel,sama5d43"
>> - "atmel,sama5d44"
>>
>> +Chipid required properties:
>> +- compatible: Should be "atmel,sama5d2-chipid"
>> +- reg : Should contain registers location and length
>> +
>> PIT Timer required properties:
>> - compatible: Should be "atmel,at91sam9260-pit"
>> - reg: Should contain registers location and length
>> diff --git a/arch/arm/mach-at91/soc.c b/arch/arm/mach-at91/soc.c
>> index 54343ff..034d563 100644
>> --- a/arch/arm/mach-at91/soc.c
>> +++ b/arch/arm/mach-at91/soc.c
>> @@ -22,48 +22,93 @@
>> #include "soc.h"
>>
>> #define AT91_DBGU_CIDR 0x40
>> -#define AT91_DBGU_CIDR_VERSION(x) ((x) & 0x1f)
>> -#define AT91_DBGU_CIDR_EXT BIT(31)
>> -#define AT91_DBGU_CIDR_MATCH_MASK 0x7fffffe0
>> #define AT91_DBGU_EXID 0x44
>> +#define AT91_CHIPID_CIDR 0x00
>> +#define AT91_CHIPID_EXID 0x04
>> +#define AT91_CIDR_VERSION(x) ((x) & 0x1f)
>> +#define AT91_CIDR_EXT BIT(31)
>> +#define AT91_CIDR_MATCH_MASK 0x7fffffe0
>>
>> -struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
>> +int __init at91_get_cidr_exid_from_dbgu(u32 *cidr, u32 *exid)
>> {
>> - struct soc_device_attribute *soc_dev_attr;
>> - const struct at91_soc *soc;
>> - struct soc_device *soc_dev;
>> struct device_node *np;
>> void __iomem *regs;
>> - u32 cidr, exid;
>>
>> np = of_find_compatible_node(NULL, NULL, "atmel,at91rm9200-dbgu");
>> if (!np)
>> np = of_find_compatible_node(NULL, NULL,
>> "atmel,at91sam9260-dbgu");
>> + if (!np)
>> + return -ENODEV;
>>
>> - if (!np) {
>> - pr_warn("Could not find DBGU node");
>> - return NULL;
>> + regs = of_iomap(np, 0);
>> + of_node_put(np);
>> +
>> + if (!regs) {
>> + pr_warn("Could not map DBGU iomem range");
>> + return -ENXIO;
>> }
>>
>> + *cidr = readl(regs + AT91_DBGU_CIDR);
>> + *exid = readl(regs + AT91_DBGU_EXID);
>> +
>> + iounmap(regs);
>> +
>> + return 0;
>> +}
>> +
>> +int __init at91_get_cidr_exid_from_chipid(u32 *cidr, u32 *exid)
>> +{
>> + struct device_node *np;
>> + void __iomem *regs;
>> +
>> + np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-chipid");
>> + if (!np)
>> + return -ENODEV;
>> +
>> regs = of_iomap(np, 0);
>> of_node_put(np);
>>
>> if (!regs) {
>> pr_warn("Could not map DBGU iomem range");
>> - return NULL;
>> + return -ENXIO;
>> }
>>
>> - cidr = readl(regs + AT91_DBGU_CIDR);
>> - exid = readl(regs + AT91_DBGU_EXID);
>> + *cidr = readl(regs + AT91_CHIPID_CIDR);
>> + *exid = readl(regs + AT91_CHIPID_EXID);
>>
>> iounmap(regs);
>>
>> + return 0;
>> +}
>> +
>> +struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
>> +{
>> + struct soc_device_attribute *soc_dev_attr;
>> + const struct at91_soc *soc;
>> + struct soc_device *soc_dev;
>> + u32 cidr, exid;
>> + int ret;
>> +
>> + /*
>> + * With SAMA5D2 and later SoCs, CIDR and EXID registers are no more
>> + * in the dbgu device but in the chipid device whose purpose is only
>> + * to expose these two registers.
>> + */
>> + ret = at91_get_cidr_exid_from_dbgu(&cidr, &exid);
>> + if (ret)
>> + ret = at91_get_cidr_exid_from_chipid(&cidr, &exid);
>> + if (ret) {
>> + if (ret == -ENODEV)
>> + pr_warn("Could not find identification node");
>> + return NULL;
>> + }
>> +
>> for (soc = socs; soc->name; soc++) {
>> - if (soc->cidr_match != (cidr & AT91_DBGU_CIDR_MATCH_MASK))
>> + if (soc->cidr_match != (cidr & AT91_CIDR_MATCH_MASK))
>> continue;
>>
>> - if (!(cidr & AT91_DBGU_CIDR_EXT) || soc->exid_match == exid)
>> + if (!(cidr & AT91_CIDR_EXT) || soc->exid_match == exid)
>> break;
>> }
>>
>> @@ -79,7 +124,7 @@ struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
>> soc_dev_attr->family = soc->family;
>> soc_dev_attr->soc_id = soc->name;
>> soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X",
>> - AT91_DBGU_CIDR_VERSION(cidr));
>> + AT91_CIDR_VERSION(cidr));
>> soc_dev = soc_device_register(soc_dev_attr);
>> if (IS_ERR(soc_dev)) {
>> kfree(soc_dev_attr->revision);
>> @@ -91,7 +136,7 @@ struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
>> if (soc->family)
>> pr_info("Detected SoC family: %s\n", soc->family);
>> pr_info("Detected SoC: %s, revision %X\n", soc->name,
>> - AT91_DBGU_CIDR_VERSION(cidr));
>> + AT91_CIDR_VERSION(cidr));
>>
>> return soc_dev;
>> }
>> --
>> 2.5.0
>>
>

--
Nicolas Ferre