Initial import

1 files changed, 403 insertions, 0 deletions

diff --git a/drivers/bus/brcmstb_gisb.c b/drivers/bus/brcmstb_gisb.c
new file mode 100644
index 000000000..738612c45
--- /dev/null
+++ b/drivers/bus/brcmstb_gisb.c
@@ -0,0 +1,403 @@
+/*
+ * 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 <linux/pm.h>
+
+#ifdef CONFIG_ARM
+#include <asm/bug.h>
+#include <asm/signal.h>
+#endif
+
+#define  ARB_ERR_CAP_CLEAR		(1 << 0)
+#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)
+
+enum {
+	ARB_TIMER,
+	ARB_ERR_CAP_CLR,
+	ARB_ERR_CAP_HI_ADDR,
+	ARB_ERR_CAP_ADDR,
+	ARB_ERR_CAP_DATA,
+	ARB_ERR_CAP_STATUS,
+	ARB_ERR_CAP_MASTER,
+};
+
+static const int gisb_offsets_bcm7038[] = {
+	[ARB_TIMER]		= 0x00c,
+	[ARB_ERR_CAP_CLR]	= 0x0c4,
+	[ARB_ERR_CAP_HI_ADDR]	= -1,
+	[ARB_ERR_CAP_ADDR]	= 0x0c8,
+	[ARB_ERR_CAP_DATA]	= 0x0cc,
+	[ARB_ERR_CAP_STATUS]	= 0x0d0,
+	[ARB_ERR_CAP_MASTER]	= -1,
+};
+
+static const int gisb_offsets_bcm7400[] = {
+	[ARB_TIMER]		= 0x00c,
+	[ARB_ERR_CAP_CLR]	= 0x0c8,
+	[ARB_ERR_CAP_HI_ADDR]	= -1,
+	[ARB_ERR_CAP_ADDR]	= 0x0cc,
+	[ARB_ERR_CAP_DATA]	= 0x0d0,
+	[ARB_ERR_CAP_STATUS]	= 0x0d4,
+	[ARB_ERR_CAP_MASTER]	= 0x0d8,
+};
+
+static const int gisb_offsets_bcm7435[] = {
+	[ARB_TIMER]		= 0x00c,
+	[ARB_ERR_CAP_CLR]	= 0x168,
+	[ARB_ERR_CAP_HI_ADDR]	= -1,
+	[ARB_ERR_CAP_ADDR]	= 0x16c,
+	[ARB_ERR_CAP_DATA]	= 0x170,
+	[ARB_ERR_CAP_STATUS]	= 0x174,
+	[ARB_ERR_CAP_MASTER]	= 0x178,
+};
+
+static const int gisb_offsets_bcm7445[] = {
+	[ARB_TIMER]		= 0x008,
+	[ARB_ERR_CAP_CLR]	= 0x7e4,
+	[ARB_ERR_CAP_HI_ADDR]	= 0x7e8,
+	[ARB_ERR_CAP_ADDR]	= 0x7ec,
+	[ARB_ERR_CAP_DATA]	= 0x7f0,
+	[ARB_ERR_CAP_STATUS]	= 0x7f4,
+	[ARB_ERR_CAP_MASTER]	= 0x7f8,
+};
+
+struct brcmstb_gisb_arb_device {
+	void __iomem	*base;
+	const int	*gisb_offsets;
+	struct mutex	lock;
+	struct list_head next;
+	u32 valid_mask;
+	const char *master_names[sizeof(u32) * BITS_PER_BYTE];
+	u32 saved_timeout;
+};
+
+static LIST_HEAD(brcmstb_gisb_arb_device_list);
+
+static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
+{
+	int offset = gdev->gisb_offsets[reg];
+
+	/* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
+	if (offset == -1)
+		return 1;
+
+	return ioread32(gdev->base + offset);
+}
+
+static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
+{
+	int offset = gdev->gisb_offsets[reg];
+
+	if (offset == -1)
+		return;
+	iowrite32(val, gdev->base + reg);
+}
+
+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 = gisb_read(gdev, 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);
+	gisb_write(gdev, val, 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 = gisb_read(gdev, 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 = gisb_read(gdev, ARB_ERR_CAP_ADDR) & 0xffffffff;
+#if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
+	arb_addr |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
+#endif
+	master = gisb_read(gdev, 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 */
+	gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
+
+	return 0;
+}
+
+#ifdef CONFIG_ARM
+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;
+}
+#endif
+
+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 const struct of_device_id brcmstb_gisb_arb_of_match[] = {
+	{ .compatible = "brcm,gisb-arb",         .data = gisb_offsets_bcm7445 },
+	{ .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
+	{ .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
+	{ .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
+	{ .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
+	{ },
+};
+
+static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
+{
+	struct device_node *dn = pdev->dev.of_node;
+	struct brcmstb_gisb_arb_device *gdev;
+	const struct of_device_id *of_id;
+	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_ioremap_resource(&pdev->dev, r);
+	if (IS_ERR(gdev->base))
+		return PTR_ERR(gdev->base);
+
+	of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
+	if (!of_id) {
+		pr_err("failed to look up compatible string\n");
+		return -EINVAL;
+	}
+	gdev->gisb_offsets = of_id->data;
+
+	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);
+
+#ifdef CONFIG_ARM
+	hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
+			"imprecise external abort");
+#endif
+
+	dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n",
+			gdev->base, timeout_irq, tea_irq);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int brcmstb_gisb_arb_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
+
+	gdev->saved_timeout = gisb_read(gdev, ARB_TIMER);
+
+	return 0;
+}
+
+/* Make sure we provide the same timeout value that was configured before, and
+ * do this before the GISB timeout interrupt handler has any chance to run.
+ */
+static int brcmstb_gisb_arb_resume_noirq(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct brcmstb_gisb_arb_device *gdev = platform_get_drvdata(pdev);
+
+	gisb_write(gdev, gdev->saved_timeout, ARB_TIMER);
+
+	return 0;
+}
+#else
+#define brcmstb_gisb_arb_suspend       NULL
+#define brcmstb_gisb_arb_resume_noirq  NULL
+#endif
+
+static const struct dev_pm_ops brcmstb_gisb_arb_pm_ops = {
+	.suspend	= brcmstb_gisb_arb_suspend,
+	.resume_noirq	= brcmstb_gisb_arb_resume_noirq,
+};
+
+static struct platform_driver brcmstb_gisb_arb_driver = {
+	.driver = {
+		.name	= "brcm-gisb-arb",
+		.of_match_table = brcmstb_gisb_arb_of_match,
+		.pm	= &brcmstb_gisb_arb_pm_ops,
+	},
+};
+
+static int __init brcm_gisb_driver_init(void)
+{
+	return platform_driver_probe(&brcmstb_gisb_arb_driver,
+				     brcmstb_gisb_arb_probe);
+}
+
+module_init(brcm_gisb_driver_init);