[PATCH v7 1/2] soc: samsung: add exynos chipid driver support
Marek Szyprowski
m.szyprowski at samsung.com
Sun Nov 6 23:35:47 PST 2016
Hi Pankaj,
On 2016-11-05 13:03, 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>
> ---
> drivers/soc/samsung/Kconfig | 5 ++
> drivers/soc/samsung/Makefile | 1 +
> drivers/soc/samsung/exynos-chipid.c | 148 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 154 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)
> + 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
> diff --git a/drivers/soc/samsung/exynos-chipid.c b/drivers/soc/samsung/exynos-chipid.c
> new file mode 100644
> index 0000000..9761e54
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-chipid.c
> @@ -0,0 +1,148 @@
> +/*
> + * 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 EXYNOS3250_SOC_ID 0xE3472000
> +#define EXYNOS4210_SOC_ID 0x43210000
> +#define EXYNOS4212_SOC_ID 0x43220000
> +#define EXYNOS4412_SOC_ID 0xE4412000
> +#define EXYNOS4415_SOC_ID 0xE4415000
> +#define EXYNOS5250_SOC_ID 0x43520000
> +#define EXYNOS5260_SOC_ID 0xE5260000
> +#define EXYNOS5410_SOC_ID 0xE5410000
> +#define EXYNOS5420_SOC_ID 0xE5420000
> +#define EXYNOS5440_SOC_ID 0xE5440000
> +#define EXYNOS5800_SOC_ID 0xE5422000
> +
> +#define EXYNOS_SOC_MASK 0xFFFFF000
> +
> +#define EXYNOS4210_REV_0 0x0
> +#define EXYNOS4210_REV_1_0 0x10
> +#define EXYNOS4210_REV_1_1 0x11
EXYNOS4210_REV* defines are not used at all in this driver.
> +
> +#define EXYNOS_SUBREV_MASK (0xF << 4)
> +#define EXYNOS_MAINREV_MASK (0xF << 0)
> +#define EXYNOS_REV_MASK (EXYNOS_SUBREV_MASK | EXYNOS_MAINREV_MASK)
> +
> +
> +static const char * __init product_id_to_soc_id(unsigned int product_id)
> +{
> + const char *soc_name;
> + unsigned int soc_id = product_id & EXYNOS_SOC_MASK;
> +
> + switch (soc_id) {
> + case EXYNOS3250_SOC_ID:
> + soc_name = "EXYNOS3250";
> + break;
> + case EXYNOS4210_SOC_ID:
> + soc_name = "EXYNOS4210";
> + break;
> + case EXYNOS4212_SOC_ID:
> + soc_name = "EXYNOS4212";
> + break;
> + case EXYNOS4412_SOC_ID:
> + soc_name = "EXYNOS4412";
> + break;
> + case EXYNOS4415_SOC_ID:
> + soc_name = "EXYNOS4415";
> + break;
> + case EXYNOS5250_SOC_ID:
> + soc_name = "EXYNOS5250";
> + break;
> + case EXYNOS5260_SOC_ID:
> + soc_name = "EXYNOS5260";
> + break;
> + case EXYNOS5420_SOC_ID:
> + soc_name = "EXYNOS5420";
> + break;
> + case EXYNOS5440_SOC_ID:
> + soc_name = "EXYNOS5440";
> + break;
> + case EXYNOS5800_SOC_ID:
> + soc_name = "EXYNOS5800";
> + break;
> + default:
> + soc_name = "UNKNOWN";
> + }
> + return soc_name;
> +}
This approach is a bit error prone. You have already missed Exynos5410
and early Exynos 4210 are not detected because of the incorrect SOC MASK.
IMHO you should replace above code and defines with a simple array,
where each ID is present only once, so it will be much easier to add
future SoCs:
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 },
{ "EXYNOS4415", 0xE4415000, 0xFFFE0000 },
{ "EXYNOS5250", 0x43520000, 0xFFFFF000 },
{ "EXYNOS5260", 0xE5260000, 0xFFFFF000 },
{ "EXYNOS5410", 0xE5410000, 0xFFFFF000 },
{ "EXYNOS5420", 0xE5420000, 0xFFFFF000 },
{ "EXYNOS5440", 0xE5440000, 0xFFFFF000 },
{ "EXYNOS5800", 0xE5422000, 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";
}
I'm also not sure about Exynos 4415, which has been scheduled for removal.
> +
> +static const struct of_device_id of_exynos_chipid_ids[] = {
> + {
> + .compatible = "samsung,exynos4210-chipid",
> + },
> + {},
> +};
> +
> +/**
> + * exynos_chipid_early_init: Early chipid initialization
> + */
> +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);
> + if (!np)
> + return -ENODEV;
> +
> + exynos_chipid_base = of_iomap(np, 0);
> +
> + if (!exynos_chipid_base)
> + return PTR_ERR(exynos_chipid_base);
> +
> + product_id = __raw_readl(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);
> +
> +
> + 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);
> + kfree(soc_dev_attr);
> + return PTR_ERR(soc_dev);
> + }
> +
> + return 0;
> +}
> +early_initcall(exynos_chipid_early_init);
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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