diff options
Diffstat (limited to 'drivers/bus/brcmstb_gisb.c')
| -rw-r--r-- | drivers/bus/brcmstb_gisb.c | 403 |
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); |