[PATCH v8 1/8] soc: samsung: add exynos chipid driver support
Pankaj Dubey
pankaj.dubey at samsung.com
Fri Dec 16 20:06:59 PST 2016
Hi Krzysztof,
On 16 December 2016 at 23:07, Krzysztof Kozlowski <krzk at kernel.org> wrote:
> On Sat, Dec 10, 2016 at 06:38:36PM +0530, Pankaj Dubey wrote:
>> Exynos SoCs have Chipid, for identification of product IDs and SoC revisions.
>> This patch intends to provide initialization code for all these functionalities,
>> at the same time it provides some sysfs entries for accessing these information
>> to user-space.
>>
>> This driver uses existing binding for exynos-chipid.
>>
>> CC: Grant Likely <grant.likely at linaro.org>
>> CC: Rob Herring <robh+dt at kernel.org>
>> CC: Linus Walleij <linus.walleij at linaro.org>
>> Signed-off-by: Pankaj Dubey <pankaj.dubey at samsung.com>
>> [m.szyprowski: for suggestion and code snippet of product_id_to_soc_id]
>> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
>> ---
>> drivers/soc/samsung/Kconfig | 5 ++
>> drivers/soc/samsung/Makefile | 1 +
>> drivers/soc/samsung/exynos-chipid.c | 116 ++++++++++++++++++++++++++++++++++++
>> 3 files changed, 122 insertions(+)
>> create mode 100644 drivers/soc/samsung/exynos-chipid.c
>>
>> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
>> index 2455339..f9ab858 100644
>> --- a/drivers/soc/samsung/Kconfig
>> +++ b/drivers/soc/samsung/Kconfig
>> @@ -14,4 +14,9 @@ config EXYNOS_PM_DOMAINS
>> bool "Exynos PM domains" if COMPILE_TEST
>> depends on PM_GENERIC_DOMAINS || COMPILE_TEST
>>
>> +config EXYNOS_CHIPID
>> + bool "Exynos Chipid controller driver" if COMPILE_TEST
>> + depends on (ARM && ARCH_EXYNOS) || ((ARM || ARM64) && COMPILE_TEST)
>
> 1. Why this can be compile tested only on ARM architectures?
Well I just used dependency same as EXYNOS_PMU, but I can see it will
be enabled for compile test on ARM64 isn't it?
> 2. Don't you need also SOC_BUS?
CHIPID needs SoC_BUS and for the same reason it is selecting SOC_BUS
in the next line.
If we mark it as a dependency (under depends on), even then we need to
select this either
under same EXYNOS_CHIPID config or ARCH_EXYNOS config.
>
>> + select SOC_BUS
>> +
>> endif
>> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
>> index 3619f2e..2a8a85e 100644
>> --- a/drivers/soc/samsung/Makefile
>> +++ b/drivers/soc/samsung/Makefile
>> @@ -1,3 +1,4 @@
>> obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o exynos3250-pmu.o exynos4-pmu.o \
>> exynos5250-pmu.o exynos5420-pmu.o
>> obj-$(CONFIG_EXYNOS_PM_DOMAINS) += pm_domains.o
>> +obj-$(CONFIG_EXYNOS_CHIPID) += exynos-chipid.o
>
> Please put it before EXYNOS_PMU, keeping this sorted alphabetical helps
> avoiding conflicts of continuous edits.
>
>> diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
>> new file mode 100644
>> index 0000000..cf0128b
>> --- /dev/null
>> +++ b/drivers/soc/samsung/exynos-chipid.c
>> @@ -0,0 +1,116 @@
>> +/*
>> + * Copyright (c) 2016 Samsung Electronics Co., Ltd.
>> + * http://www.samsung.com/
>> + *
>> + * EXYNOS - CHIP ID support
>> + * Author: Pankaj Dubey <pankaj.dubey at samsung.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/io.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include <linux/sys_soc.h>
>> +
>> +#define EXYNOS_SUBREV_MASK (0xF << 4)
>> +#define EXYNOS_MAINREV_MASK (0xF << 0)
>> +#define EXYNOS_REV_MASK (EXYNOS_SUBREV_MASK | EXYNOS_MAINREV_MASK)
>> +
>> +static const struct exynos_soc_id {
>> + const char *name;
>> + unsigned int id;
>> + unsigned int mask;
>> +} soc_ids[] = {
>> + { "EXYNOS3250", 0xE3472000, 0xFFFFF000 },
>> + { "EXYNOS4210", 0x43200000, 0xFFFE0000 },
>> + { "EXYNOS4212", 0x43220000, 0xFFFE0000 },
>> + { "EXYNOS4412", 0xE4412000, 0xFFFE0000 },
>> + { "EXYNOS5250", 0x43520000, 0xFFFFF000 },
>> + { "EXYNOS5260", 0xE5260000, 0xFFFFF000 },
>> + { "EXYNOS5410", 0xE5410000, 0xFFFFF000 },
>> + { "EXYNOS5420", 0xE5420000, 0xFFFFF000 },
>> + { "EXYNOS5440", 0xE5440000, 0xFFFFF000 },
>> + { "EXYNOS5800", 0xE5422000, 0xFFFFF000 },
>> + { "EXYNOS7420", 0xE7420000, 0xFFFFF000 },
>> + { "EXYNOS5433", 0xE5433000, 0xFFFFF000 },
>> +};
>> +
>> +static const char * __init product_id_to_soc_id(unsigned int product_id)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < ARRAY_SIZE(soc_ids); i++)
>> + if ((product_id & soc_ids[i].mask) == soc_ids[i].id)
>> + return soc_ids[i].name;
>> + return "UNKNOWN";
>> +}
>> +
>> +static const struct of_device_id of_exynos_chipid_ids[] = {
>> + {
>> + .compatible = "samsung,exynos4210-chipid",
>> + },
>> + {},
>> +};
>> +
>> +/**
>> + * exynos_chipid_early_init: Early chipid initialization
>> + */
>
> This comment is meaningless, it duplicates the name of function.
Ok, will remove this in v9.
>
>> +int __init exynos_chipid_early_init(void)
>> +{
>> + struct soc_device_attribute *soc_dev_attr;
>> + struct soc_device *soc_dev;
>> + struct device_node *root;
>> + struct device_node *np;
>> + void __iomem *exynos_chipid_base;
>> + const struct of_device_id *match;
>> + u32 product_id;
>> + u32 revision;
>> +
>> + np = of_find_matching_node_and_match(NULL,
>> + of_exynos_chipid_ids, &match);
>
> You don't use the match here, so how about either
> of_find_matching_node() or of_find_compatible_node()? The latter looks
> better (less calls inside) and actually you want just check one
> compatible field?
>
Ok, will adopt this in v9.
>> + if (!np)
>> + return -ENODEV;
>> +
>> + exynos_chipid_base = of_iomap(np, 0);
>> +
>> + if (!exynos_chipid_base)
>> + return PTR_ERR(exynos_chipid_base);
>> +
>> + product_id = readl_relaxed(exynos_chipid_base);
>
> Duplicated space before '='.
Ok, will fix this.
>
>> + revision = product_id & EXYNOS_REV_MASK;
>> + iounmap(exynos_chipid_base);
>> +
>> + soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
>> + if (!soc_dev_attr)
>> + return -ENODEV;
>> +
>> + soc_dev_attr->family = "Samsung Exynos";
>> +
>> + root = of_find_node_by_path("/");
>> + of_property_read_string(root, "model", &soc_dev_attr->machine);
>> + of_node_put(root);
>> +
>> + soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%x", revision);
>> + soc_dev_attr->soc_id = product_id_to_soc_id(product_id);
>> +
>> +
>> + pr_info("Exynos: CPU[%s] CPU_REV[0x%x] Detected\n",
>> + product_id_to_soc_id(product_id), revision);
>> +
>> + soc_dev = soc_device_register(soc_dev_attr);
>> + if (IS_ERR(soc_dev)) {
>> + kfree(soc_dev_attr->revision);
>> + kfree_const(soc_dev_attr->soc_id);
>
> It wasn't allocated with *_const, so no need to free it.
Yes, will fix this.
>
> Best regards,
> Krzysztof
Thanks for review.
Pankaj Dubey
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