1 files changed, 289 insertions, 0 deletions
diff --git a/drivers/bus/brcmstb_gisb.c b/drivers/bus/brcmstb_gisb.c
new file mode 100644
index 000000000000..6159b7752a64
--- /dev/null
+++ b/drivers/bus/brcmstb_gisb.c
@@ -0,0 +1,289 @@
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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.
+ *
+ * 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/init.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/sysfs.h>
+#include <linux/io.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/bitops.h>
+
+#include <asm/bug.h>
+#include <asm/signal.h>
+
+#define ARB_TIMER			0x008
+#define ARB_ERR_CAP_CLR			0x7e4
+#define  ARB_ERR_CAP_CLEAR		(1 << 0)
+#define ARB_ERR_CAP_HI_ADDR		0x7e8
+#define ARB_ERR_CAP_ADDR		0x7ec
+#define ARB_ERR_CAP_DATA		0x7f0
+#define ARB_ERR_CAP_STATUS		0x7f4
+#define  ARB_ERR_CAP_STATUS_TIMEOUT	(1 << 12)
+#define  ARB_ERR_CAP_STATUS_TEA		(1 << 11)
+#define  ARB_ERR_CAP_STATUS_BS_SHIFT	(1 << 2)
+#define  ARB_ERR_CAP_STATUS_BS_MASK	0x3c
+#define  ARB_ERR_CAP_STATUS_WRITE	(1 << 1)
+#define  ARB_ERR_CAP_STATUS_VALID	(1 << 0)
+#define ARB_ERR_CAP_MASTER		0x7f8
+
+struct brcmstb_gisb_arb_device {
+	void __iomem	*base;
+	struct mutex	lock;
+	struct list_head next;
+	u32 valid_mask;
+	const char *master_names[sizeof(u32) * BITS_PER_BYTE];
+};
+
+static LIST_HEAD(brcmstb_gisb_arb_device_list);
+
+static ssize_t gisb_arb_get_timeout(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
+	u32 timeout;
+
+	mutex_lock(&gdev->lock);
+	timeout = ioread32(gdev->base + ARB_TIMER);
+	mutex_unlock(&gdev->lock);
+
+	return sprintf(buf, "%d", timeout);
+}
+
+static ssize_t gisb_arb_set_timeout(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
+	int val, ret;
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val == 0 || val >= 0xffffffff)
+		return -EINVAL;
+
+	mutex_lock(&gdev->lock);
+	iowrite32(val, gdev->base + ARB_TIMER);
+	mutex_unlock(&gdev->lock);
+
+	return count;
+}
+
+static const char *
+brcmstb_gisb_master_to_str(struct brcmstb_gisb_arb_device *gdev,
+						u32 masters)
+{
+	u32 mask = gdev->valid_mask & masters;
+
+	if (hweight_long(mask) != 1)
+		return NULL;
+
+	return gdev->master_names[ffs(mask) - 1];
+}
+
+static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
+					const char *reason)
+{
+	u32 cap_status;
+	unsigned long arb_addr;
+	u32 master;
+	const char *m_name;
+	char m_fmt[11];
+
+	cap_status = ioread32(gdev->base + ARB_ERR_CAP_STATUS);
+
+	/* Invalid captured address, bail out */
+	if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
+		return 1;
+
+	/* Read the address and master */
+	arb_addr = ioread32(gdev->base + ARB_ERR_CAP_ADDR) & 0xffffffff;
+#if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
+	arb_addr |= (u64)ioread32(gdev->base + ARB_ERR_CAP_HI_ADDR) << 32;
+#endif
+	master = ioread32(gdev->base + ARB_ERR_CAP_MASTER);
+
+	m_name = brcmstb_gisb_master_to_str(gdev, master);
+	if (!m_name) {
+		snprintf(m_fmt, sizeof(m_fmt), "0x%08x", master);
+		m_name = m_fmt;
+	}
+
+	pr_crit("%s: %s at 0x%lx [%c %s], core: %s\n",
+		__func__, reason, arb_addr,
+		cap_status & ARB_ERR_CAP_STATUS_WRITE ? 'W' : 'R',
+		cap_status & ARB_ERR_CAP_STATUS_TIMEOUT ? "timeout" : "",
+		m_name);
+
+	/* clear the GISB error */
+	iowrite32(ARB_ERR_CAP_CLEAR, gdev->base + ARB_ERR_CAP_CLR);
+
+	return 0;
+}
+
+static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
+				     struct pt_regs *regs)
+{
+	int ret = 0;
+	struct brcmstb_gisb_arb_device *gdev;
+
+	/* iterate over each GISB arb registered handlers */
+	list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next)
+		ret |= brcmstb_gisb_arb_decode_addr(gdev, "bus error");
+	/*
+	 * If it was an imprecise abort, then we need to correct the
+	 * return address to be _after_ the instruction.
+	*/
+	if (fsr & (1 << 10))
+		regs->ARM_pc += 4;
+
+	return ret;
+}
+
+void __init brcmstb_hook_fault_code(void)
+{
+	hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
+			"imprecise external abort");
+}
+
+static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
+{
+	brcmstb_gisb_arb_decode_addr(dev_id, "timeout");
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id)
+{
+	brcmstb_gisb_arb_decode_addr(dev_id, "target abort");
+
+	return IRQ_HANDLED;
+}
+
+static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO,
+		gisb_arb_get_timeout, gisb_arb_set_timeout);
+
+static struct attribute *gisb_arb_sysfs_attrs[] = {
+	&dev_attr_gisb_arb_timeout.attr,
+	NULL,
+};
+
+static struct attribute_group gisb_arb_sysfs_attr_group = {
+	.attrs = gisb_arb_sysfs_attrs,
+};
+
+static int brcmstb_gisb_arb_probe(struct platform_device *pdev)
+{
+	struct device_node *dn = pdev->dev.of_node;
+	struct brcmstb_gisb_arb_device *gdev;
+	struct resource *r;
+	int err, timeout_irq, tea_irq;
+	unsigned int num_masters, j = 0;
+	int i, first, last;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	timeout_irq = platform_get_irq(pdev, 0);
+	tea_irq = platform_get_irq(pdev, 1);
+
+	gdev = devm_kzalloc(&pdev->dev, sizeof(*gdev), GFP_KERNEL);
+	if (!gdev)
+		return -ENOMEM;
+
+	mutex_init(&gdev->lock);
+	INIT_LIST_HEAD(&gdev->next);
+
+	gdev->base = devm_request_and_ioremap(&pdev->dev, r);
+	if (!gdev->base)
+		return -ENOMEM;
+
+	err = devm_request_irq(&pdev->dev, timeout_irq,
+				brcmstb_gisb_timeout_handler, 0, pdev->name,
+				gdev);
+	if (err < 0)
+		return err;
+
+	err = devm_request_irq(&pdev->dev, tea_irq,
+				brcmstb_gisb_tea_handler, 0, pdev->name,
+				gdev);
+	if (err < 0)
+		return err;
+
+	/* If we do not have a valid mask, assume all masters are enabled */
+	if (of_property_read_u32(dn, "brcm,gisb-arb-master-mask",
+				&gdev->valid_mask))
+		gdev->valid_mask = 0xffffffff;
+
+	/* Proceed with reading the litteral names if we agree on the
+	 * number of masters
+	 */
+	num_masters = of_property_count_strings(dn,
+			"brcm,gisb-arb-master-names");
+	if (hweight_long(gdev->valid_mask) == num_masters) {
+		first = ffs(gdev->valid_mask) - 1;
+		last = fls(gdev->valid_mask) - 1;
+
+		for (i = first; i < last; i++) {
+			if (!(gdev->valid_mask & BIT(i)))
+				continue;
+
+			of_property_read_string_index(dn,
+					"brcm,gisb-arb-master-names", j,
+					&gdev->master_names[i]);
+			j++;
+		}
+	}
+
+	err = sysfs_create_group(&pdev->dev.kobj, &gisb_arb_sysfs_attr_group);
+	if (err)
+		return err;
+
+	platform_set_drvdata(pdev, gdev);
+
+	list_add_tail(&gdev->next, &brcmstb_gisb_arb_device_list);
+
+	dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
+			gdev->base, timeout_irq, tea_irq);
+
+	return 0;
+}
+
+static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
+	{ .compatible = "brcm,gisb-arb" },
+	{ },
+};
+
+static struct platform_driver brcmstb_gisb_arb_driver = {
+	.probe	= brcmstb_gisb_arb_probe,
+	.driver = {
+		.name	= "brcm-gisb-arb",
+		.owner	= THIS_MODULE,
+		.of_match_table = brcmstb_gisb_arb_of_match,
+	},
+};
+
+static int __init brcm_gisb_driver_init(void)
+{
+	return platform_driver_register(&brcmstb_gisb_arb_driver);
+}
+
+module_init(brcm_gisb_driver_init);