[PATCH v6 0/2] Introducing Exynos ChipId driver

[PATCH v6 0/2] Introducing Exynos ChipId driver

[Pankaj Dubey]

Once again I am respinning this quite old patch series to introduce 
Exynos Chipid driver.

This patch series introduces Exynos Chipid platform driver.
Each Exynos SoC has ChipID block which can give information about SoC's
product Id and revision number.
At the same time it reduces dependency of mach-exynos files from plat-samsung,
by removing samsung_rev API, similar API is introduced in chipid driver itself
to get revision number and product id. 

I have tested this patch series on Exynos5880 based Chromebook for
normal system boot and S2R.

Revisiion 5 and it's discussion can be found here
 - http://lists.infradead.org/pipermail/linux-arm-kernel/2014-December/310046.html
Revision 4 and it's discussion can be found here
 - https://lkml.org/lkml/2014/12/3/115

Change since v5:
 - Addressed Rob's review comments.
 - Rebased on latest krzk/for-next branch and retested.

Changes since v4:
 - Removed custom sysfs entries as they were not providing any new information
   as pointed out by Arnd.
 - Removed functions exporting product_id and revision, instead we will export
   exynos_chipid_info structure. It will be helpfull when we need to provide more
   fields of chipid outside of chipid, as commented by Yadwinder
 - Converted all funcions as __init. 

Change since v3: 
 - This patch set contains 5/6 and 6/6 patch from v3 series.
 - Made EXYNOS_CHIPID config option non-user selectable,
   as suggested by Tomasz Figa.
 - Made uniform macro for EXYNOS4/5_SOC_MASK as EXYNOS_SOC_MASK as
   suggested by Tomasz Figa.
 - Made local variables static in chipid driver.
 - Added existing SoC's product id's.
 - Added platform driver support.

Changes since v2:
 - Reorganized patches as suggested by Tomasz Figa.
 - Addressed review comments of Tomasz Figa in i2c-s3c2410.c file.

Changes since v1:
 - Added patch to move i2c interrupt re-configuration code from exynos.c
   to i2c driver, as suggested by Arnd.
 - After above patch only user of SYS_I2C_CFG register is pm.c so moving
   save/restore of this register also into i2c driver.
 - Spiltted up exynos4 and exynos5 machine descriptors to get rid from
   soc_is_exynos4/exynos5 kind of macros, as suggested by Arnd.
 - Changed location of chipid driver to "drivers/soc".
 - Added drivers/base/soc.c provided infrastructure to make SoC specific 
   information avaible to user space via sysfs entry, as suggested by Arnd.

Pankaj Dubey (2):
  soc: samsung: add exynos chipid driver support
  ARM: EXYNOS: refactoring of mach-exynos to enable chipid driver

 arch/arm/mach-exynos/Kconfig                 |   1 +
 arch/arm/mach-exynos/common.h                |  53 ++++-----
 arch/arm/mach-exynos/exynos.c                |  49 ++------
 arch/arm/mach-exynos/include/mach/map.h      |   2 -
 arch/arm/mach-exynos/platsmp.c               |   2 +-
 arch/arm/mach-exynos/pm.c                    |   8 +-
 arch/arm/plat-samsung/cpu.c                  |  14 ---
 arch/arm/plat-samsung/include/plat/cpu.h     |   2 -
 arch/arm/plat-samsung/include/plat/map-s5p.h |   1 -
 drivers/soc/samsung/Kconfig                  |   5 +
 drivers/soc/samsung/Makefile                 |   1 +
 drivers/soc/samsung/exynos-chipid.c          | 172 +++++++++++++++++++++++++++
 include/linux/soc/samsung/exynos-soc.h       |  51 ++++++++
 13 files changed, 266 insertions(+), 95 deletions(-)
 create mode 100644 drivers/soc/samsung/exynos-chipid.c
 create mode 100644 include/linux/soc/samsung/exynos-soc.h

-- 
2.4.5

[PATCH v6 1/2] soc: samsung: add exynos chipid driver support

[Pankaj Dubey]

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@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
---
 drivers/soc/samsung/Kconfig            |   5 +
 drivers/soc/samsung/Makefile           |   1 +
 drivers/soc/samsung/exynos-chipid.c    | 172 +++++++++++++++++++++++++++++++++
 include/linux/soc/samsung/exynos-soc.h |  51 ++++++++++
 4 files changed, 229 insertions(+)
 create mode 100644 drivers/soc/samsung/exynos-chipid.c
 create mode 100644 include/linux/soc/samsung/exynos-soc.h

diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
index d7fc123..fc793f3 100644
--- a/drivers/soc/samsung/Kconfig
+++ b/drivers/soc/samsung/Kconfig
@@ -10,4 +10,9 @@ config EXYNOS_PMU
 	bool "Exynos PMU controller driver" if COMPILE_TEST
 	depends on (ARM && ARCH_EXYNOS) || ((ARM || ARM64) && 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 f64ac4d..81023ed 100644
--- a/drivers/soc/samsung/Makefile
+++ b/drivers/soc/samsung/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_EXYNOS_PMU)	+= exynos-pmu.o exynos3250-pmu.o exynos4-pmu.o \
 					exynos5250-pmu.o exynos5420-pmu.o
+obj-$(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..fa20fdd
--- /dev/null
+++ b/drivers/soc/samsung/exynos-chipid.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *	      http://www.samsung.com/
+ *
+ * EXYNOS - CHIP ID support
+ * Author: Pankaj Dubey <pankaj.dubey@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>
+#include <linux/soc/samsung/exynos-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 void __iomem *exynos_chipid_base;
+
+struct exynos_chipid_info exynos_soc_info;
+EXPORT_SYMBOL(exynos_soc_info);
+
+static const char * __init product_id_to_name(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;
+}
+
+static const struct of_device_id of_exynos_chipid_ids[] = {
+	{
+		.compatible	= "samsung,exynos4210-chipid",
+	},
+	{},
+};
+
+/**
+ *  exynos_chipid_early_init: Early chipid initialization
+ *  @dev: pointer to chipid device
+ */
+int __init exynos_chipid_early_init(struct device *dev)
+{
+	struct device_node *np;
+	const struct of_device_id *match;
+
+	if (exynos_chipid_base)
+		return 0;
+
+	if (!dev)
+		np = of_find_matching_node_and_match(NULL,
+			of_exynos_chipid_ids, &match);
+	else
+		np = dev->of_node;
+
+	if (!np)
+		return -ENODEV;
+
+	exynos_chipid_base = of_iomap(np, 0);
+
+	if (!exynos_chipid_base)
+		return PTR_ERR(exynos_chipid_base);
+	
+	exynos_soc_info.product_id  = __raw_readl(exynos_chipid_base);
+	exynos_soc_info.revision = exynos_soc_info.product_id & EXYNOS_REV_MASK;
+
+	return 0;
+}
+
+static int __init exynos_chipid_probe(struct platform_device *pdev)
+{
+	struct soc_device_attribute *soc_dev_attr;
+	struct soc_device *soc_dev;
+	struct device_node *root;
+	int ret;
+
+	ret = exynos_chipid_early_init(&pdev->dev);
+	if (ret) {
+		dev_dbg(&pdev->dev, "Exynos chipid probe failed: %d\n", ret);
+		return ret;
+	}
+
+	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("/");
+	ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
+	of_node_put(root);
+	if (ret)
+		goto free_soc;
+
+	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%d",
+					exynos_soc_info.revision);
+	if (!soc_dev_attr->revision)
+		goto free_soc;
+
+	soc_dev_attr->soc_id = product_id_to_name(exynos_soc_info.product_id);
+
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev))
+		goto free_rev;
+
+	soc_device_to_device(soc_dev);
+
+	dev_info(&pdev->dev, "Exynos: CPU[%s] CPU_REV[0x%x] Detected\n",
+			product_id_to_name(exynos_soc_info.product_id),
+			exynos_soc_info.revision);
+	return 0;
+free_rev:
+	kfree(soc_dev_attr->revision);
+free_soc:
+	kfree(soc_dev_attr);
+	return -EINVAL;
+}
+
+static struct platform_driver exynos_chipid_driver = {
+	.driver = {
+		.name = "exynos-chipid",
+		.of_match_table = of_exynos_chipid_ids,
+	},
+};
+
+static int __init exynos_chipid_init(void)
+{
+	return platform_driver_probe(&exynos_chipid_driver, exynos_chipid_probe);
+}
+device_initcall(exynos_chipid_init);
diff --git a/include/linux/soc/samsung/exynos-soc.h b/include/linux/soc/samsung/exynos-soc.h
new file mode 100644
index 0000000..38b95ad
--- /dev/null
+++ b/include/linux/soc/samsung/exynos-soc.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Header for EXYNOS SoC Chipid support
+ *
+ * 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.
+ */
+
+#ifndef __EXYNOS_SOC_H
+#define __EXYNOS_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
+
+/**
+ * Struct exynos_chipid_info
+ * @soc_product_id: product id allocated to exynos SoC
+ * @soc_revision: revision of exynos SoC
+ */
+
+struct exynos_chipid_info {
+	u32 product_id;
+	u32 revision;
+};
+
+extern struct exynos_chipid_info exynos_soc_info;
+
+/* Since we need chipid to be initialized as early as possible
+ * during secondary core bootup adding early initialization function
+ */
+extern int exynos_chipid_early_init(struct device *dev);
+
+#endif /* __EXYNOS_SOC_H */
-- 
2.4.5

[PATCH v6 2/2] ARM: EXYNOS: refactoring of mach-exynos to enable chipid driver

[Pankaj Dubey]

This patch enables chipid driver for ARCH_EXYNOS and refactors
machine code for using chipid driver for identification of
SoC ID and SoC rev.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
---
 arch/arm/mach-exynos/Kconfig                 |  1 +
 arch/arm/mach-exynos/common.h                | 53 ++++++++++++----------------
 arch/arm/mach-exynos/exynos.c                | 49 +++++--------------------
 arch/arm/mach-exynos/include/mach/map.h      |  2 --
 arch/arm/mach-exynos/platsmp.c               |  2 +-
 arch/arm/mach-exynos/pm.c                    |  8 ++---
 arch/arm/plat-samsung/cpu.c                  | 14 --------
 arch/arm/plat-samsung/include/plat/cpu.h     |  2 --
 arch/arm/plat-samsung/include/plat/map-s5p.h |  1 -
 9 files changed, 37 insertions(+), 95 deletions(-)

diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 20dcf6e..f93c790 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -16,6 +16,7 @@ menuconfig ARCH_EXYNOS
 	select ARM_AMBA
 	select ARM_GIC
 	select COMMON_CLK_SAMSUNG
+	select EXYNOS_CHIPID
 	select EXYNOS_THERMAL
 	select EXYNOS_PMU
 	select EXYNOS_SROM
diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
index 5365bf1..566ad2b 100644
--- a/arch/arm/mach-exynos/common.h
+++ b/arch/arm/mach-exynos/common.h
@@ -13,39 +13,26 @@
 #define __ARCH_ARM_MACH_EXYNOS_COMMON_H
 
 #include <linux/platform_data/cpuidle-exynos.h>
+#include <linux/soc/samsung/exynos-soc.h>
 
-#define EXYNOS3250_SOC_ID	0xE3472000
-#define EXYNOS3_SOC_MASK	0xFFFFF000
-
-#define EXYNOS4210_CPU_ID	0x43210000
-#define EXYNOS4212_CPU_ID	0x43220000
-#define EXYNOS4412_CPU_ID	0xE4412200
-#define EXYNOS4_CPU_MASK	0xFFFE0000
-
-#define EXYNOS5250_SOC_ID	0x43520000
-#define EXYNOS5410_SOC_ID	0xE5410000
-#define EXYNOS5420_SOC_ID	0xE5420000
-#define EXYNOS5440_SOC_ID	0xE5440000
-#define EXYNOS5800_SOC_ID	0xE5422000
-#define EXYNOS5_SOC_MASK	0xFFFFF000
-
-extern unsigned long samsung_cpu_id;
+static inline u32 exynos_product_id(void);
 
 #define IS_SAMSUNG_CPU(name, id, mask)		\
 static inline int is_samsung_##name(void)	\
 {						\
-	return ((samsung_cpu_id & mask) == (id & mask));	\
+	u32 product_id = exynos_product_id();	\
+	return ((product_id & mask) == (id));	\
 }
 
-IS_SAMSUNG_CPU(exynos3250, EXYNOS3250_SOC_ID, EXYNOS3_SOC_MASK)
-IS_SAMSUNG_CPU(exynos4210, EXYNOS4210_CPU_ID, EXYNOS4_CPU_MASK)
-IS_SAMSUNG_CPU(exynos4212, EXYNOS4212_CPU_ID, EXYNOS4_CPU_MASK)
-IS_SAMSUNG_CPU(exynos4412, EXYNOS4412_CPU_ID, EXYNOS4_CPU_MASK)
-IS_SAMSUNG_CPU(exynos5250, EXYNOS5250_SOC_ID, EXYNOS5_SOC_MASK)
-IS_SAMSUNG_CPU(exynos5410, EXYNOS5410_SOC_ID, EXYNOS5_SOC_MASK)
-IS_SAMSUNG_CPU(exynos5420, EXYNOS5420_SOC_ID, EXYNOS5_SOC_MASK)
-IS_SAMSUNG_CPU(exynos5440, EXYNOS5440_SOC_ID, EXYNOS5_SOC_MASK)
-IS_SAMSUNG_CPU(exynos5800, EXYNOS5800_SOC_ID, EXYNOS5_SOC_MASK)
+IS_SAMSUNG_CPU(exynos3250, EXYNOS3250_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos4210, EXYNOS4210_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos4212, EXYNOS4212_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos4412, EXYNOS4412_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos5250, EXYNOS5250_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos5410, EXYNOS5410_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos5420, EXYNOS5420_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos5440, EXYNOS5440_SOC_ID, EXYNOS_SOC_MASK)
+IS_SAMSUNG_CPU(exynos5800, EXYNOS5800_SOC_ID, EXYNOS_SOC_MASK)
 
 #if defined(CONFIG_SOC_EXYNOS3250)
 # define soc_is_exynos3250()	is_samsung_exynos3250()
@@ -71,10 +58,6 @@ IS_SAMSUNG_CPU(exynos5800, EXYNOS5800_SOC_ID, EXYNOS5_SOC_MASK)
 # define soc_is_exynos4412()	0
 #endif
 
-#define EXYNOS4210_REV_0	(0x0)
-#define EXYNOS4210_REV_1_0	(0x10)
-#define EXYNOS4210_REV_1_1	(0x11)
-
 #if defined(CONFIG_SOC_EXYNOS5250)
 # define soc_is_exynos5250()	is_samsung_exynos5250()
 #else
@@ -172,6 +155,16 @@ extern void exynos_core_restart(u32 core_id);
 extern int exynos_set_boot_addr(u32 core_id, unsigned long boot_addr);
 extern int exynos_get_boot_addr(u32 core_id, unsigned long *boot_addr);
 
+static inline u32 exynos_product_id(void)
+{
+	return exynos_soc_info.product_id;
+}
+
+static inline u32 exynos_revision(void)
+{
+	return exynos_soc_info.revision;
+}
+
 static inline void pmu_raw_writel(u32 val, u32 offset)
 {
 	__raw_writel(val, pmu_base_addr + offset);
diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
index f977eea..89d7254 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c
@@ -92,50 +92,11 @@ static void __init exynos_init_late(void)
 	exynos_pm_init();
 }
 
-static int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
-					int depth, void *data)
-{
-	struct map_desc iodesc;
-	const __be32 *reg;
-	int len;
-
-	if (!of_flat_dt_is_compatible(node, "samsung,exynos4210-chipid") &&
-		!of_flat_dt_is_compatible(node, "samsung,exynos5440-clock"))
-		return 0;
-
-	reg = of_get_flat_dt_prop(node, "reg", &len);
-	if (reg == NULL || len != (sizeof(unsigned long) * 2))
-		return 0;
-
-	iodesc.pfn = __phys_to_pfn(be32_to_cpu(reg[0]));
-	iodesc.length = be32_to_cpu(reg[1]) - 1;
-	iodesc.virtual = (unsigned long)S5P_VA_CHIPID;
-	iodesc.type = MT_DEVICE;
-	iotable_init(&iodesc, 1);
-	return 1;
-}
-
-/*
- * exynos_map_io
- *
- * register the standard cpu IO areas
- */
-static void __init exynos_map_io(void)
-{
-	if (soc_is_exynos4())
-		iotable_init(exynos4_iodesc, ARRAY_SIZE(exynos4_iodesc));
-}
-
 static void __init exynos_init_io(void)
 {
 	debug_ll_io_init();
-
-	of_scan_flat_dt(exynos_fdt_map_chipid, NULL);
-
-	/* detect cpu id and rev. */
-	s5p_init_cpu(S5P_VA_CHIPID);
-
-	exynos_map_io();
+	if (soc_is_exynos4())
+		iotable_init(exynos4_iodesc, ARRAY_SIZE(exynos4_iodesc));
 }
 
 /*
@@ -187,6 +148,8 @@ static void exynos_map_pmu(void)
 
 static void __init exynos_init_irq(void)
 {
+	int ret;
+
 	irqchip_init();
 	/*
 	 * Since platsmp.c needs pmu base address by the time
@@ -194,6 +157,10 @@ static void __init exynos_init_irq(void)
 	 * init_irq
 	 */
 	exynos_map_pmu();
+
+	ret = exynos_chipid_early_init(NULL);
+	if (ret)
+		pr_warn("Exynos chipid early initialization failed\n");
 }
 
 static const struct of_device_id exynos_cpufreq_matches[] = {
diff --git a/arch/arm/mach-exynos/include/mach/map.h b/arch/arm/mach-exynos/include/mach/map.h
index c48ba4f..15548ef 100644
--- a/arch/arm/mach-exynos/include/mach/map.h
+++ b/arch/arm/mach-exynos/include/mach/map.h
@@ -16,8 +16,6 @@
 
 #include <plat/map-s5p.h>
 
-#define EXYNOS_PA_CHIPID		0x10000000
-
 #define EXYNOS4_PA_CMU			0x10030000
 
 #define EXYNOS4_PA_DMC0			0x10400000
diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 85c3be6..a45528d 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -170,7 +170,7 @@ int exynos_cluster_power_state(int cluster)
 
 static void __iomem *cpu_boot_reg_base(void)
 {
-	if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
+	if (soc_is_exynos4210() && exynos_revision() == EXYNOS4210_REV_1_1)
 		return pmu_base_addr + S5P_INFORM5;
 	return sysram_base_addr;
 }
diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index c43b776..cd120ac 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -32,18 +32,18 @@
 
 static inline void __iomem *exynos_boot_vector_addr(void)
 {
-	if (samsung_rev() == EXYNOS4210_REV_1_1)
+	if (exynos_revision() == EXYNOS4210_REV_1_1)
 		return pmu_base_addr + S5P_INFORM7;
-	else if (samsung_rev() == EXYNOS4210_REV_1_0)
+	else if (exynos_revision() == EXYNOS4210_REV_1_0)
 		return sysram_base_addr + 0x24;
 	return pmu_base_addr + S5P_INFORM0;
 }
 
 static inline void __iomem *exynos_boot_vector_flag(void)
 {
-	if (samsung_rev() == EXYNOS4210_REV_1_1)
+	if (exynos_revision() == EXYNOS4210_REV_1_1)
 		return pmu_base_addr + S5P_INFORM6;
-	else if (samsung_rev() == EXYNOS4210_REV_1_0)
+	else if (exynos_revision() == EXYNOS4210_REV_1_0)
 		return sysram_base_addr + 0x20;
 	return pmu_base_addr + S5P_INFORM1;
 }
diff --git a/arch/arm/plat-samsung/cpu.c b/arch/arm/plat-samsung/cpu.c
index 71333bb..02d95fd 100644
--- a/arch/arm/plat-samsung/cpu.c
+++ b/arch/arm/plat-samsung/cpu.c
@@ -21,12 +21,6 @@
 unsigned long samsung_cpu_id;
 static unsigned int samsung_cpu_rev;
 
-unsigned int samsung_rev(void)
-{
-	return samsung_cpu_rev;
-}
-EXPORT_SYMBOL(samsung_rev);
-
 void __init s3c64xx_init_cpu(void)
 {
 	samsung_cpu_id = __raw_readl(S3C_VA_SYS + 0x118);
@@ -43,11 +37,3 @@ void __init s3c64xx_init_cpu(void)
 
 	pr_info("Samsung CPU ID: 0x%08lx\n", samsung_cpu_id);
 }
-
-void __init s5p_init_cpu(void __iomem *cpuid_addr)
-{
-	samsung_cpu_id = __raw_readl(cpuid_addr);
-	samsung_cpu_rev = samsung_cpu_id & 0xFF;
-
-	pr_info("Samsung CPU ID: 0x%08lx\n", samsung_cpu_id);
-}
diff --git a/arch/arm/plat-samsung/include/plat/cpu.h b/arch/arm/plat-samsung/include/plat/cpu.h
index 61d14f3..fa7d0d6 100644
--- a/arch/arm/plat-samsung/include/plat/cpu.h
+++ b/arch/arm/plat-samsung/include/plat/cpu.h
@@ -114,8 +114,6 @@ extern void s3c24xx_init_io(struct map_desc *mach_desc, int size);
 
 extern void s3c64xx_init_cpu(void);
 
-extern unsigned int samsung_rev(void);
-
 extern void s3c24xx_init_uarts(struct s3c2410_uartcfg *cfg, int no);
 
 extern void s3c24xx_init_clocks(int xtal);
diff --git a/arch/arm/plat-samsung/include/plat/map-s5p.h b/arch/arm/plat-samsung/include/plat/map-s5p.h
index b63aeeb..3708ae5 100644
--- a/arch/arm/plat-samsung/include/plat/map-s5p.h
+++ b/arch/arm/plat-samsung/include/plat/map-s5p.h
@@ -13,7 +13,6 @@
 #ifndef __ASM_PLAT_MAP_S5P_H
 #define __ASM_PLAT_MAP_S5P_H __FILE__
 
-#define S5P_VA_CHIPID		S3C_ADDR(0x02000000)
 #define S5P_VA_CMU		S3C_ADDR(0x02100000)
 
 #define S5P_VA_DMC0		S3C_ADDR(0x02440000)
-- 
2.4.5

Re: [PATCH v6 1/2] soc: samsung: add exynos chipid driver support

[Arnd Bergmann]

On Wednesday, May 25, 2016 1:28:23 PM CEST 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@linaro.org>
> CC: Rob Herring <robh+dt@kernel.org>
> CC: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> ---
>  drivers/soc/samsung/Kconfig            |   5 +
>  drivers/soc/samsung/Makefile           |   1 +
>  drivers/soc/samsung/exynos-chipid.c    | 172 +++++++++++++++++++++++++++++++++
>  include/linux/soc/samsung/exynos-soc.h |  51 ++++++++++
> 


I don't like how this exposes the internals of the samsung SoC in a global header
file, after we spent a considerable amount of work on keeping it confined
to arch/arm/{mach-exynos,mach-s3c64xx,plat-samsung}.

Please remove the external interface of the driver, in particular the global
data structure. We keep coming back to this for a lot of platforms, and
I still think we should have an architecture-independent way of matching
platforms to struct soc_device, using an exported function from drivers/base/soc.c
that uses glob_match() to compare a platform string against the running system.

	Arnd