[PATCH v2 7/7] soc: renesas: Identify SoC and register with the SoC bus

From: Geert Uytterhoeven
Date: Mon Oct 31 2016 - 07:32:31 EST


Identify the SoC type and revision, and register this information with
the SoC bus, so it is available under /sys/devices/soc0/, and can be
checked where needed using soc_device_match().

Identification is done using the Product Register or Common Chip Code
Register, as declared in DT, or using a hardcoded fallback if missing.

Example:

Detected Renesas r8a7791 (0x47) ES1.0
...
# cat /sys/devices/soc0/{family,machine,soc_id,revision}
Renesas
Koelsch
r8a7791
ES1.0

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v2:
- Drop SoC families and family names; use fixed "Renesas" instead,
- Drop EMEV2, which doesn't have a chip ID register, and doesn't share
devices with other SoCs,
- Drop RZ/A1H and R-CAR M1A, which don't have chip ID registers (for
M1A: not accessible from the ARM core?),
- On arm, move "select SOC_BUS" from ARCH_RENESAS to Kconfig symbols
for SoCs that provide a chip ID register,
- Build renesas-soc only if SOC_BUS is enabled,
- Use "renesas,prr" and "renesas,cccr" device nodes in DT if
available, else fall back to hardcoded addresses for compatibility
with existing DTBs,
- Remove verification of product IDs; just print the ID instead,
- Don't register the SoC bus if the chip ID register is missing,
- Change R-Mobile APE6 fallback to use PRR instead of CCCR (it has
both).
---
arch/arm/mach-shmobile/Kconfig | 3 +
arch/arm64/Kconfig.platforms | 1 +
drivers/soc/renesas/Makefile | 2 +
drivers/soc/renesas/renesas-soc.c | 130 ++++++++++++++++++++++++++++++++++++++
4 files changed, 136 insertions(+)
create mode 100644 drivers/soc/renesas/renesas-soc.c

diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index 6fbd9b7d2d67a18f..dd4d52dd71b4eab2 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -21,11 +21,13 @@ config ARCH_RCAR_GEN2
select PM
select PM_GENERIC_DOMAINS
select RENESAS_IRQC
+ select SOC_BUS
select SYS_SUPPORTS_SH_CMT

config ARCH_RMOBILE
bool
select PM_RMOBILE
+ select SOC_BUS
select SYS_SUPPORTS_SH_CMT
select SYS_SUPPORTS_SH_TMU

@@ -80,6 +82,7 @@ config ARCH_R8A7778
config ARCH_R8A7779
bool "R-Car H1 (R8A77790)"
select ARCH_RCAR_GEN1
+ select SOC_BUS

config ARCH_R8A7790
bool "R-Car H2 (R8A77900)"
diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index 101794f5ce1008b7..b751c6891c6a51ed 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -143,6 +143,7 @@ config ARCH_RENESAS
select PM
select PM_GENERIC_DOMAINS
select RENESAS_IRQC
+ select SOC_BUS
help
This enables support for the ARMv8 based Renesas SoCs.

diff --git a/drivers/soc/renesas/Makefile b/drivers/soc/renesas/Makefile
index 9e0bb329594c4fca..1652df037955e0e6 100644
--- a/drivers/soc/renesas/Makefile
+++ b/drivers/soc/renesas/Makefile
@@ -1,3 +1,5 @@
+obj-$(CONFIG_SOC_BUS) += renesas-soc.o
+
obj-$(CONFIG_ARCH_R8A7743) += rcar-sysc.o r8a7743-sysc.o
obj-$(CONFIG_ARCH_R8A7779) += rcar-sysc.o r8a7779-sysc.o
obj-$(CONFIG_ARCH_R8A7790) += rcar-sysc.o r8a7790-sysc.o
diff --git a/drivers/soc/renesas/renesas-soc.c b/drivers/soc/renesas/renesas-soc.c
new file mode 100644
index 0000000000000000..01104bfaefdb9f32
--- /dev/null
+++ b/drivers/soc/renesas/renesas-soc.c
@@ -0,0 +1,130 @@
+/*
+ * Renesas SoC Identification
+ *
+ * Copyright (C) 2014-2016 Glider bvba
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sys_soc.h>
+
+
+#define CCCR 0xe600101c /* Common Chip Code Register */
+#define PRR 0xff000044 /* Product Register */
+#define PRR3 0xfff00044 /* Product Register on R-Car Gen3 */
+
+static const struct of_device_id renesas_socs[] __initconst = {
+#ifdef CONFIG_ARCH_R8A73A4
+ { .compatible = "renesas,r8a73a4", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7740
+ { .compatible = "renesas,r8a7740", .data = (void *)CCCR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7743
+ { .compatible = "renesas,r8a7743", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7745
+ { .compatible = "renesas,r8a7745", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7779
+ { .compatible = "renesas,r8a7779", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7790
+ { .compatible = "renesas,r8a7790", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7791
+ { .compatible = "renesas,r8a7791", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7792
+ { .compatible = "renesas,r8a7792", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7793
+ { .compatible = "renesas,r8a7793", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7794
+ { .compatible = "renesas,r8a7794", .data = (void *)PRR, },
+#endif
+#ifdef CONFIG_ARCH_R8A7795
+ { .compatible = "renesas,r8a7795", .data = (void *)PRR3, },
+#endif
+#ifdef CONFIG_ARCH_R8A7796
+ { .compatible = "renesas,r8a7796", .data = (void *)PRR3, },
+#endif
+#ifdef CONFIG_ARCH_SH73A0
+ { .compatible = "renesas,sh73a0", .data = (void *)CCCR, },
+#endif
+ { /* sentinel */ }
+};
+
+static int __init renesas_soc_init(void)
+{
+ struct soc_device_attribute *soc_dev_attr;
+ const struct of_device_id *match;
+ void __iomem *chipid = NULL;
+ struct soc_device *soc_dev;
+ struct device_node *np;
+ unsigned int product;
+
+ np = of_find_matching_node_and_match(NULL, renesas_socs, &match);
+ if (!np)
+ return -ENODEV;
+
+ of_node_put(np);
+
+ /* Try PRR first, then CCCR, then hardcoded fallback */
+ np = of_find_compatible_node(NULL, NULL, "renesas,prr");
+ if (!np)
+ np = of_find_compatible_node(NULL, NULL, "renesas,cccr");
+ if (np) {
+ chipid = of_iomap(np, 0);
+ of_node_put(np);
+ } else if (match->data) {
+ chipid = ioremap((uintptr_t)match->data, 4);
+ }
+ if (!chipid)
+ return -ENODEV;
+
+ product = readl(chipid);
+ iounmap(chipid);
+
+ soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ np = of_find_node_by_path("/");
+ of_property_read_string(np, "model", &soc_dev_attr->machine);
+ of_node_put(np);
+
+ soc_dev_attr->family = "Renesas";
+ soc_dev_attr->revision = kasprintf(GFP_KERNEL, "ES%u.%u",
+ ((product >> 4) & 0xf) + 1,
+ product & 0xf);
+ soc_dev_attr->soc_id = kstrdup_const(strchr(match->compatible, ',') + 1,
+ GFP_KERNEL);
+ pr_info("Detected %s %s (0x%02x) %s\n", soc_dev_attr->family,
+ soc_dev_attr->soc_id, (product >> 8) & 0xff,
+ soc_dev_attr->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;
+}
+core_initcall(renesas_soc_init);
--
1.9.1