summaryrefslogtreecommitdiffstats
path: root/kernel/arch/arm/mach-mvebu/mvebu-soc-id.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/arch/arm/mach-mvebu/mvebu-soc-id.c')
-rw-r--r--kernel/arch/arm/mach-mvebu/mvebu-soc-id.c178
1 files changed, 178 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-mvebu/mvebu-soc-id.c b/kernel/arch/arm/mach-mvebu/mvebu-soc-id.c
new file mode 100644
index 000000000..a99434bce
--- /dev/null
+++ b/kernel/arch/arm/mach-mvebu/mvebu-soc-id.c
@@ -0,0 +1,178 @@
+/*
+ * ID and revision information for mvebu SoCs
+ *
+ * Copyright (C) 2014 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@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.
+ *
+ * All the mvebu SoCs have information related to their variant and
+ * revision that can be read from the PCI control register. This is
+ * done before the PCI initialization to avoid any conflict. Once the
+ * ID and revision are retrieved, the mapping is freed.
+ */
+
+#define pr_fmt(fmt) "mvebu-soc-id: " fmt
+
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/sys_soc.h>
+#include "common.h"
+#include "mvebu-soc-id.h"
+
+#define PCIE_DEV_ID_OFF 0x0
+#define PCIE_DEV_REV_OFF 0x8
+
+#define SOC_ID_MASK 0xFFFF0000
+#define SOC_REV_MASK 0xFF
+
+static u32 soc_dev_id;
+static u32 soc_rev;
+static bool is_id_valid;
+
+static const struct of_device_id mvebu_pcie_of_match_table[] = {
+ { .compatible = "marvell,armada-xp-pcie", },
+ { .compatible = "marvell,armada-370-pcie", },
+ { .compatible = "marvell,kirkwood-pcie" },
+ {},
+};
+
+int mvebu_get_soc_id(u32 *dev, u32 *rev)
+{
+ if (is_id_valid) {
+ *dev = soc_dev_id;
+ *rev = soc_rev;
+ return 0;
+ } else
+ return -ENODEV;
+}
+
+static int __init get_soc_id_by_pci(void)
+{
+ struct device_node *np;
+ int ret = 0;
+ void __iomem *pci_base;
+ struct clk *clk;
+ struct device_node *child;
+
+ np = of_find_matching_node(NULL, mvebu_pcie_of_match_table);
+ if (!np)
+ return ret;
+
+ /*
+ * ID and revision are available from any port, so we
+ * just pick the first one
+ */
+ child = of_get_next_child(np, NULL);
+ if (child == NULL) {
+ pr_err("cannot get pci node\n");
+ ret = -ENOMEM;
+ goto clk_err;
+ }
+
+ clk = of_clk_get_by_name(child, NULL);
+ if (IS_ERR(clk)) {
+ pr_err("cannot get clock\n");
+ ret = -ENOMEM;
+ goto clk_err;
+ }
+
+ ret = clk_prepare_enable(clk);
+ if (ret) {
+ pr_err("cannot enable clock\n");
+ goto clk_err;
+ }
+
+ pci_base = of_iomap(child, 0);
+ if (pci_base == NULL) {
+ pr_err("cannot map registers\n");
+ ret = -ENOMEM;
+ goto res_ioremap;
+ }
+
+ /* SoC ID */
+ soc_dev_id = readl(pci_base + PCIE_DEV_ID_OFF) >> 16;
+
+ /* SoC revision */
+ soc_rev = readl(pci_base + PCIE_DEV_REV_OFF) & SOC_REV_MASK;
+
+ is_id_valid = true;
+
+ pr_info("MVEBU SoC ID=0x%X, Rev=0x%X\n", soc_dev_id, soc_rev);
+
+ iounmap(pci_base);
+
+res_ioremap:
+ /*
+ * If the PCIe unit is actually enabled and we have PCI
+ * support in the kernel, we intentionally do not release the
+ * reference to the clock. We want to keep it running since
+ * the bootloader does some PCIe link configuration that the
+ * kernel is for now unable to do, and gating the clock would
+ * make us loose this precious configuration.
+ */
+ if (!of_device_is_available(child) || !IS_ENABLED(CONFIG_PCI_MVEBU)) {
+ clk_disable_unprepare(clk);
+ clk_put(clk);
+ }
+
+clk_err:
+ of_node_put(child);
+ of_node_put(np);
+
+ return ret;
+}
+
+static int __init mvebu_soc_id_init(void)
+{
+
+ /*
+ * First try to get the ID and the revision by the system
+ * register and use PCI registers only if it is not possible
+ */
+ if (!mvebu_system_controller_get_soc_id(&soc_dev_id, &soc_rev)) {
+ is_id_valid = true;
+ pr_info("MVEBU SoC ID=0x%X, Rev=0x%X\n", soc_dev_id, soc_rev);
+ return 0;
+ }
+
+ return get_soc_id_by_pci();
+}
+early_initcall(mvebu_soc_id_init);
+
+static int __init mvebu_soc_device(void)
+{
+ struct soc_device_attribute *soc_dev_attr;
+ struct soc_device *soc_dev;
+
+ /* Also protects against running on non-mvebu systems */
+ if (!is_id_valid)
+ return 0;
+
+ soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+ if (!soc_dev_attr)
+ return -ENOMEM;
+
+ soc_dev_attr->family = kasprintf(GFP_KERNEL, "Marvell");
+ soc_dev_attr->revision = kasprintf(GFP_KERNEL, "%X", soc_rev);
+ soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "%X", soc_dev_id);
+
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR(soc_dev)) {
+ kfree(soc_dev_attr->family);
+ kfree(soc_dev_attr->revision);
+ kfree(soc_dev_attr->soc_id);
+ kfree(soc_dev_attr);
+ }
+
+ return 0;
+}
+postcore_initcall(mvebu_soc_device);