ARM: at91: move SoC detection to its own driver

To simplify machine init and as the soc_device struct is not used as the
parent for on-chip devices anymore, move SoC detection to its own driver.

Change in dmesg:
 - before:
DMA: preallocated 256 KiB pool for atomic coherent allocations
AT91: Detected SoC family: sama5d2
AT91: Detected SoC: sama5d27, revision 0
No ATAGs?
clocksource: tcb_clksrc: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 184217874325 ns
at_xdmac f0010000.dma-controller: 16 channels, mapped at 0xe085b000
SCSI subsystem initialized

 - after:
DMA: preallocated 256 KiB pool for atomic coherent allocations
No ATAGs?
clocksource: tcb_clksrc: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 184217874325 ns
at_xdmac f0010000.dma-controller: 16 channels, mapped at 0xe0859000
AT91: Detected SoC family: sama5d2
AT91: Detected SoC: sama5d27, revision 0
SCSI subsystem initialized

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

6 files changed, 331 insertions, 0 deletions

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index f09023f7ab11..45e5b13a3c02 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,5 +1,6 @@
 menu "SOC (System On Chip) specific Drivers"
 
+source "drivers/soc/atmel/Kconfig"
 source "drivers/soc/bcm/Kconfig"
 source "drivers/soc/fsl/Kconfig"
 source "drivers/soc/mediatek/Kconfig"
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 05eae52a30b4..3467de7d3890 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -2,6 +2,7 @@
 # Makefile for the Linux Kernel SOC specific device drivers.
 #
 
+obj-$(CONFIG_ARCH_AT91)		+= atmel/
 obj-y				+= bcm/
 obj-$(CONFIG_ARCH_DOVE)		+= dove/
 obj-$(CONFIG_MACH_DOVE)		+= dove/
diff --git a/drivers/soc/atmel/Kconfig b/drivers/soc/atmel/Kconfig
new file mode 100644
index 000000000000..6242ebb41abb
--- /dev/null
+++ b/drivers/soc/atmel/Kconfig
@@ -0,0 +1,6 @@
+config AT91_SOC_ID
+	bool "SoC bus for Atmel ARM SoCs"
+	depends on ARCH_AT91 || COMPILE_TEST
+	default ARCH_AT91
+	help
+	  Include support for the SoC bus on the Atmel ARM SoCs.
diff --git a/drivers/soc/atmel/Makefile b/drivers/soc/atmel/Makefile
new file mode 100644
index 000000000000..2d92f32e4ea5
--- /dev/null
+++ b/drivers/soc/atmel/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_AT91_SOC_ID) += soc.o
diff --git a/drivers/soc/atmel/soc.c b/drivers/soc/atmel/soc.c
new file mode 100644
index 000000000000..4790094b498e
--- /dev/null
+++ b/drivers/soc/atmel/soc.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 2015 Atmel
+ *
+ * Alexandre Belloni <alexandre.belloni@free-electrons.com
+ * Boris Brezillon <boris.brezillon@free-electrons.com
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ */
+
+#define pr_fmt(fmt)	"AT91: " fmt
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+
+#include "soc.h"
+
+#define AT91_DBGU_CIDR			0x40
+#define AT91_DBGU_EXID			0x44
+#define AT91_CHIPID_CIDR		0x00
+#define AT91_CHIPID_EXID		0x04
+#define AT91_CIDR_VERSION(x)		((x) & 0x1f)
+#define AT91_CIDR_EXT			BIT(31)
+#define AT91_CIDR_MATCH_MASK		0x7fffffe0
+
+static const struct at91_soc __initconst socs[] = {
+#ifdef CONFIG_SOC_AT91RM9200
+	AT91_SOC(AT91RM9200_CIDR_MATCH, 0, "at91rm9200 BGA", "at91rm9200"),
+#endif
+#ifdef CONFIG_SOC_AT91SAM9
+	AT91_SOC(AT91SAM9260_CIDR_MATCH, 0, "at91sam9260", NULL),
+	AT91_SOC(AT91SAM9261_CIDR_MATCH, 0, "at91sam9261", NULL),
+	AT91_SOC(AT91SAM9263_CIDR_MATCH, 0, "at91sam9263", NULL),
+	AT91_SOC(AT91SAM9G20_CIDR_MATCH, 0, "at91sam9g20", NULL),
+	AT91_SOC(AT91SAM9RL64_CIDR_MATCH, 0, "at91sam9rl64", NULL),
+	AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9M11_EXID_MATCH,
+		 "at91sam9m11", "at91sam9g45"),
+	AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9M10_EXID_MATCH,
+		 "at91sam9m10", "at91sam9g45"),
+	AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9G46_EXID_MATCH,
+		 "at91sam9g46", "at91sam9g45"),
+	AT91_SOC(AT91SAM9G45_CIDR_MATCH, AT91SAM9G45_EXID_MATCH,
+		 "at91sam9g45", "at91sam9g45"),
+	AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9G15_EXID_MATCH,
+		 "at91sam9g15", "at91sam9x5"),
+	AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9G35_EXID_MATCH,
+		 "at91sam9g35", "at91sam9x5"),
+	AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9X35_EXID_MATCH,
+		 "at91sam9x35", "at91sam9x5"),
+	AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9G25_EXID_MATCH,
+		 "at91sam9g25", "at91sam9x5"),
+	AT91_SOC(AT91SAM9X5_CIDR_MATCH, AT91SAM9X25_EXID_MATCH,
+		 "at91sam9x25", "at91sam9x5"),
+	AT91_SOC(AT91SAM9N12_CIDR_MATCH, AT91SAM9CN12_EXID_MATCH,
+		 "at91sam9cn12", "at91sam9n12"),
+	AT91_SOC(AT91SAM9N12_CIDR_MATCH, AT91SAM9N12_EXID_MATCH,
+		 "at91sam9n12", "at91sam9n12"),
+	AT91_SOC(AT91SAM9N12_CIDR_MATCH, AT91SAM9CN11_EXID_MATCH,
+		 "at91sam9cn11", "at91sam9n12"),
+	AT91_SOC(AT91SAM9XE128_CIDR_MATCH, 0, "at91sam9xe128", "at91sam9xe128"),
+	AT91_SOC(AT91SAM9XE256_CIDR_MATCH, 0, "at91sam9xe256", "at91sam9xe256"),
+	AT91_SOC(AT91SAM9XE512_CIDR_MATCH, 0, "at91sam9xe512", "at91sam9xe512"),
+#endif
+#ifdef CONFIG_SOC_SAMA5
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D21CU_EXID_MATCH,
+		 "sama5d21", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D22CU_EXID_MATCH,
+		 "sama5d22", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D23CU_EXID_MATCH,
+		 "sama5d23", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D24CX_EXID_MATCH,
+		 "sama5d24", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D24CU_EXID_MATCH,
+		 "sama5d24", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D26CU_EXID_MATCH,
+		 "sama5d26", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D27CU_EXID_MATCH,
+		 "sama5d27", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D27CN_EXID_MATCH,
+		 "sama5d27", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D28CU_EXID_MATCH,
+		 "sama5d28", "sama5d2"),
+	AT91_SOC(SAMA5D2_CIDR_MATCH, SAMA5D28CN_EXID_MATCH,
+		 "sama5d28", "sama5d2"),
+	AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D31_EXID_MATCH,
+		 "sama5d31", "sama5d3"),
+	AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D33_EXID_MATCH,
+		 "sama5d33", "sama5d3"),
+	AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D34_EXID_MATCH,
+		 "sama5d34", "sama5d3"),
+	AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D35_EXID_MATCH,
+		 "sama5d35", "sama5d3"),
+	AT91_SOC(SAMA5D3_CIDR_MATCH, SAMA5D36_EXID_MATCH,
+		 "sama5d36", "sama5d3"),
+	AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D41_EXID_MATCH,
+		 "sama5d41", "sama5d4"),
+	AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D42_EXID_MATCH,
+		 "sama5d42", "sama5d4"),
+	AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D43_EXID_MATCH,
+		 "sama5d43", "sama5d4"),
+	AT91_SOC(SAMA5D4_CIDR_MATCH, SAMA5D44_EXID_MATCH,
+		 "sama5d44", "sama5d4"),
+#endif
+	{ /* sentinel */ },
+};
+
+static int __init at91_get_cidr_exid_from_dbgu(u32 *cidr, u32 *exid)
+{
+	struct device_node *np;
+	void __iomem *regs;
+
+	np = of_find_compatible_node(NULL, NULL, "atmel,at91rm9200-dbgu");
+	if (!np)
+		np = of_find_compatible_node(NULL, NULL,
+					     "atmel,at91sam9260-dbgu");
+	if (!np)
+		return -ENODEV;
+
+	regs = of_iomap(np, 0);
+	of_node_put(np);
+
+	if (!regs) {
+		pr_warn("Could not map DBGU iomem range");
+		return -ENXIO;
+	}
+
+	*cidr = readl(regs + AT91_DBGU_CIDR);
+	*exid = readl(regs + AT91_DBGU_EXID);
+
+	iounmap(regs);
+
+	return 0;
+}
+
+static int __init at91_get_cidr_exid_from_chipid(u32 *cidr, u32 *exid)
+{
+	struct device_node *np;
+	void __iomem *regs;
+
+	np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-chipid");
+	if (!np)
+		return -ENODEV;
+
+	regs = of_iomap(np, 0);
+	of_node_put(np);
+
+	if (!regs) {
+		pr_warn("Could not map DBGU iomem range");
+		return -ENXIO;
+	}
+
+	*cidr = readl(regs + AT91_CHIPID_CIDR);
+	*exid = readl(regs + AT91_CHIPID_EXID);
+
+	iounmap(regs);
+
+	return 0;
+}
+
+struct soc_device * __init at91_soc_init(const struct at91_soc *socs)
+{
+	struct soc_device_attribute *soc_dev_attr;
+	const struct at91_soc *soc;
+	struct soc_device *soc_dev;
+	u32 cidr, exid;
+	int ret;
+
+	/*
+	 * With SAMA5D2 and later SoCs, CIDR and EXID registers are no more
+	 * in the dbgu device but in the chipid device whose purpose is only
+	 * to expose these two registers.
+	 */
+	ret = at91_get_cidr_exid_from_dbgu(&cidr, &exid);
+	if (ret)
+		ret = at91_get_cidr_exid_from_chipid(&cidr, &exid);
+	if (ret) {
+		if (ret == -ENODEV)
+			pr_warn("Could not find identification node");
+		return NULL;
+	}
+
+	for (soc = socs; soc->name; soc++) {
+		if (soc->cidr_match != (cidr & AT91_CIDR_MATCH_MASK))
+			continue;
+
+		if (!(cidr & AT91_CIDR_EXT) || soc->exid_match == exid)
+			break;
+	}
+
+	if (!soc->name) {
+		pr_warn("Could not find matching SoC description\n");
+		return NULL;
+	}
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return NULL;
+
+	soc_dev_attr->family = soc->family;
+	soc_dev_attr->soc_id = soc->name;
+	soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X",
+					   AT91_CIDR_VERSION(cidr));
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr->revision);
+		kfree(soc_dev_attr);
+		pr_warn("Could not register SoC device\n");
+		return NULL;
+	}
+
+	if (soc->family)
+		pr_info("Detected SoC family: %s\n", soc->family);
+	pr_info("Detected SoC: %s, revision %X\n", soc->name,
+		AT91_CIDR_VERSION(cidr));
+
+	return soc_dev;
+}
+
+static int __init atmel_soc_device_init(void)
+{
+	at91_soc_init(socs);
+
+	return 0;
+}
+subsys_initcall(atmel_soc_device_init);
diff --git a/drivers/soc/atmel/soc.h b/drivers/soc/atmel/soc.h
new file mode 100644
index 000000000000..228efded5085
--- /dev/null
+++ b/drivers/soc/atmel/soc.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2015 Atmel
+ *
+ * Boris Brezillon <boris.brezillon@free-electrons.com
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ */
+
+#ifndef __AT91_SOC_H
+#define __AT91_SOC_H
+
+#include <linux/sys_soc.h>
+
+struct at91_soc {
+	u32 cidr_match;
+	u32 exid_match;
+	const char *name;
+	const char *family;
+};
+
+#define AT91_SOC(__cidr, __exid, __name, __family)		\
+	{							\
+		.cidr_match = (__cidr),				\
+		.exid_match = (__exid),				\
+		.name = (__name),				\
+		.family = (__family),				\
+	}
+
+struct soc_device * __init
+at91_soc_init(const struct at91_soc *socs);
+
+#define AT91RM9200_CIDR_MATCH		0x09290780
+
+#define AT91SAM9260_CIDR_MATCH		0x019803a0
+#define AT91SAM9261_CIDR_MATCH		0x019703a0
+#define AT91SAM9263_CIDR_MATCH		0x019607a0
+#define AT91SAM9G20_CIDR_MATCH		0x019905a0
+#define AT91SAM9RL64_CIDR_MATCH		0x019b03a0
+#define AT91SAM9G45_CIDR_MATCH		0x019b05a0
+#define AT91SAM9X5_CIDR_MATCH		0x019a05a0
+#define AT91SAM9N12_CIDR_MATCH		0x019a07a0
+
+#define AT91SAM9M11_EXID_MATCH		0x00000001
+#define AT91SAM9M10_EXID_MATCH		0x00000002
+#define AT91SAM9G46_EXID_MATCH		0x00000003
+#define AT91SAM9G45_EXID_MATCH		0x00000004
+
+#define AT91SAM9G15_EXID_MATCH		0x00000000
+#define AT91SAM9G35_EXID_MATCH		0x00000001
+#define AT91SAM9X35_EXID_MATCH		0x00000002
+#define AT91SAM9G25_EXID_MATCH		0x00000003
+#define AT91SAM9X25_EXID_MATCH		0x00000004
+
+#define AT91SAM9CN12_EXID_MATCH		0x00000005
+#define AT91SAM9N12_EXID_MATCH		0x00000006
+#define AT91SAM9CN11_EXID_MATCH		0x00000009
+
+#define AT91SAM9XE128_CIDR_MATCH	0x329973a0
+#define AT91SAM9XE256_CIDR_MATCH	0x329a93a0
+#define AT91SAM9XE512_CIDR_MATCH	0x329aa3a0
+
+#define SAMA5D2_CIDR_MATCH		0x0a5c08c0
+#define SAMA5D21CU_EXID_MATCH		0x0000005a
+#define SAMA5D22CU_EXID_MATCH		0x00000059
+#define SAMA5D22CN_EXID_MATCH		0x00000069
+#define SAMA5D23CU_EXID_MATCH		0x00000058
+#define SAMA5D24CX_EXID_MATCH		0x00000004
+#define SAMA5D24CU_EXID_MATCH		0x00000014
+#define SAMA5D26CU_EXID_MATCH		0x00000012
+#define SAMA5D27CU_EXID_MATCH		0x00000011
+#define SAMA5D27CN_EXID_MATCH		0x00000021
+#define SAMA5D28CU_EXID_MATCH		0x00000010
+#define SAMA5D28CN_EXID_MATCH		0x00000020
+
+#define SAMA5D3_CIDR_MATCH		0x0a5c07c0
+#define SAMA5D31_EXID_MATCH		0x00444300
+#define SAMA5D33_EXID_MATCH		0x00414300
+#define SAMA5D34_EXID_MATCH		0x00414301
+#define SAMA5D35_EXID_MATCH		0x00584300
+#define SAMA5D36_EXID_MATCH		0x00004301
+
+#define SAMA5D4_CIDR_MATCH		0x0a5c07c0
+#define SAMA5D41_EXID_MATCH		0x00000001
+#define SAMA5D42_EXID_MATCH		0x00000002
+#define SAMA5D43_EXID_MATCH		0x00000003
+#define SAMA5D44_EXID_MATCH		0x00000004
+
+#endif /* __AT91_SOC_H */