[PATCH v9 04/12] soc: samsung: add exynos chipid driver support

[Marek Szyprowski]

Hi Pankaj

On 2017-03-30 15:16, 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 | 109 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 115 insertions(+)
>   create mode 100644 drivers/soc/samsung/exynos-chipid.c
>
> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
> index 8b25bd5..a90a4ad 100644
> --- a/drivers/soc/samsung/Kconfig
> +++ b/drivers/soc/samsung/Kconfig
> @@ -6,6 +6,11 @@ menuconfig SOC_SAMSUNG
>   
>   if SOC_SAMSUNG
>   
> +config EXYNOS_CHIPID
> +	bool "Exynos Chipid controller driver" if COMPILE_TEST
> +	depends on ARCH_EXYNOS || COMPILE_TEST
> +	select SOC_BUS
> +
>   config EXYNOS_PMU
>   	bool "Exynos PMU controller driver" if COMPILE_TEST
>   	depends on ARCH_EXYNOS || ((ARM || ARM64) && COMPILE_TEST)
> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
> index 4d7694a..be3b6bb 100644
> --- a/drivers/soc/samsung/Makefile
> +++ b/drivers/soc/samsung/Makefile
> @@ -1,3 +1,4 @@
> +obj-$(CONFIG_EXYNOS_CHIPID)	+= exynos-chipid.o
>   obj-$(CONFIG_EXYNOS_PMU)	+= exynos-pmu.o
>   
>   obj-$(CONFIG_EXYNOS_PMU_ARM_DRIVERS)	+= exynos3250-pmu.o exynos4-pmu.o \
> diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
> new file mode 100644
> index 0000000..1e9fb6b
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-chipid.c
> @@ -0,0 +1,109 @@
> +/*
> + * Copyright (c) 2017 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", 0x43210000, 0xFFFFF000 },

You have once again changed the mask for Exynos4 SoCs, so please add
following line to the above array:

{ "EXYNOS4210", 0x43200000, 0xFFFFF000 },       /* EVT0 revision */

Otherwise Exynos C210 (4210 EVT0) is not properly detected:

soc soc0: Exynos: CPU[UNKNOWN] PRO_ID[0x43200200] REV[0x0] Detected

> +	{ "EXYNOS4212", 0x43220000, 0xFFFFF000 },
> +	{ "EXYNOS4412", 0xE4412000, 0xFFFFF000 },
> +	{ "EXYNOS5250", 0x43520000, 0xFFFFF000 },
> +	{ "EXYNOS5260", 0xE5260000, 0xFFFFF000 },
> +	{ "EXYNOS5410", 0xE5410000, 0xFFFFF000 },
> +	{ "EXYNOS5420", 0xE5420000, 0xFFFFF000 },
> +	{ "EXYNOS5440", 0xE5440000, 0xFFFFF000 },
> +	{ "EXYNOS5800", 0xE5422000, 0xFFFFF000 },
> +	{ "EXYNOS7420", 0xE7420000, 0xFFFFF000 },
> +	{ "EXYNOS5433", 0xE5433000, 0xFFFFF000 },
> +};

Now the mask is same for all revisions, so you can remove it from the above
array and directly use some kind of define in the code.

> +
> +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";
> +}
> +
> +int __init exynos_chipid_early_init(void)
> +{
> +	struct soc_device_attribute *soc_dev_attr;
> +	void __iomem *exynos_chipid_base;
> +	struct soc_device *soc_dev;
> +	struct device_node *root;
> +	struct device_node *np;
> +	struct device *dev;
> +	u32 product_id;
> +	u32 revision;
> +
> +	/* look up for chipid node */
> +	np = of_find_compatible_node(NULL, NULL, "samsung,exynos4210-chipid");
> +	if (!np)
> +		return -ENODEV;
> +
> +	exynos_chipid_base = of_iomap(np, 0);
> +	of_node_put(np);
> +
> +	if (!exynos_chipid_base) {
> +		pr_err("%s: failed to map chipid\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	product_id = readl_relaxed(exynos_chipid_base);
> +	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);
> +
> +	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);
> +		kfree(soc_dev_attr);
> +		return PTR_ERR(soc_dev);
> +	}
> +	dev = soc_device_to_device(soc_dev);
> +
> +	dev_info(dev, "Exynos: CPU[%s] PRO_ID[0x%x] REV[0x%x] Detected\n",
> +			soc_dev_attr->soc_id, product_id, revision);
> +
> +	return 0;
> +}
> +early_initcall(exynos_chipid_early_init);

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland