--- /dev/null
+/*
+ * 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);
projects / linux-beck.git / commitdiff