diff options
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/bus/Makefile | 1 | ||||
| -rw-r--r-- | drivers/bus/bt1-axi.c | 320 |
3 files changed, 336 insertions, 0 deletions
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig index 6d4e4497b59b..1080dd26e268 100644 --- a/drivers/bus/Kconfig +++ b/drivers/bus/Kconfig @@ -29,6 +29,21 @@ config BRCMSTB_GISB_ARB arbiter. This driver provides timeout and target abort error handling and internal bus master decoding. +config BT1_AXI + tristate "Baikal-T1 AXI-bus driver" + depends on MIPS_BAIKAL_T1 || COMPILE_TEST + select MFD_SYSCON + help + AXI3-bus is the main communication bus connecting all high-speed + peripheral IP-cores with RAM controller and with MIPS P5600 cores on + Baikal-T1 SoC. Traffic arbitration is done by means of DW AMBA 3 AXI + Interconnect (so called AXI Main Interconnect) routing IO requests + from one SoC block to another. This driver provides a way to detect + any bus protocol errors and device not responding situations by + means of an embedded on top of the interconnect errors handler + block (EHB). AXI Interconnect QoS arbitration tuning is currently + unsupported. + config MOXTET tristate "CZ.NIC Turris Mox module configuration bus" depends on SPI_MASTER && OF diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile index 05f32cd694a4..eaa25d171ebd 100644 --- a/drivers/bus/Makefile +++ b/drivers/bus/Makefile @@ -13,6 +13,7 @@ obj-$(CONFIG_MOXTET) += moxtet.o # DPAA2 fsl-mc bus obj-$(CONFIG_FSL_MC_BUS) += fsl-mc/ +obj-$(CONFIG_BT1_AXI) += bt1-axi.o obj-$(CONFIG_IMX_WEIM) += imx-weim.o obj-$(CONFIG_MIPS_CDMM) += mips_cdmm.o obj-$(CONFIG_MVEBU_MBUS) += mvebu-mbus.o diff --git a/drivers/bus/bt1-axi.c b/drivers/bus/bt1-axi.c new file mode 100644 index 000000000000..2005f9174118 --- /dev/null +++ b/drivers/bus/bt1-axi.c @@ -0,0 +1,320 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC + * + * Authors: + * Serge Semin <Sergey.Semin@baikalelectronics.ru> + * + * Baikal-T1 AXI-bus driver + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/bitfield.h> +#include <linux/device.h> +#include <linux/atomic.h> +#include <linux/regmap.h> +#include <linux/platform_device.h> +#include <linux/mfd/syscon.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/nmi.h> +#include <linux/of.h> +#include <linux/clk.h> +#include <linux/reset.h> +#include <linux/sysfs.h> + +#define BT1_AXI_WERRL 0x110 +#define BT1_AXI_WERRH 0x114 +#define BT1_AXI_WERRH_TYPE BIT(23) +#define BT1_AXI_WERRH_ADDR_FLD 24 +#define BT1_AXI_WERRH_ADDR_MASK GENMASK(31, BT1_AXI_WERRH_ADDR_FLD) + +/* + * struct bt1_axi - Baikal-T1 AXI-bus private data + * @dev: Pointer to the device structure. + * @qos_regs: AXI Interconnect QoS tuning registers. + * @sys_regs: Baikal-T1 System Controller registers map. + * @irq: Errors IRQ number. + * @aclk: AXI reference clock. + * @arst: AXI Interconnect reset line. + * @count: Number of errors detected. + */ +struct bt1_axi { + struct device *dev; + + void __iomem *qos_regs; + struct regmap *sys_regs; + int irq; + + struct clk *aclk; + + struct reset_control *arst; + + atomic_t count; +}; + +static irqreturn_t bt1_axi_isr(int irq, void *data) +{ + struct bt1_axi *axi = data; + u32 low = 0, high = 0; + + regmap_read(axi->sys_regs, BT1_AXI_WERRL, &low); + regmap_read(axi->sys_regs, BT1_AXI_WERRH, &high); + + dev_crit_ratelimited(axi->dev, + "AXI-bus fault %d: %s at 0x%x%08x\n", + atomic_inc_return(&axi->count), + high & BT1_AXI_WERRH_TYPE ? "no slave" : "slave protocol error", + high, low); + + /* + * Print backtrace on each CPU. This might be pointless if the fault + * has happened on the same CPU as the IRQ handler is executed or + * the other core proceeded further execution despite the error. + * But if it's not, by looking at the trace we would get straight to + * the cause of the problem. + */ + trigger_all_cpu_backtrace(); + + return IRQ_HANDLED; +} + +static void bt1_axi_clear_data(void *data) +{ + struct bt1_axi *axi = data; + struct platform_device *pdev = to_platform_device(axi->dev); + + platform_set_drvdata(pdev, NULL); +} + +static struct bt1_axi *bt1_axi_create_data(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bt1_axi *axi; + int ret; + + axi = devm_kzalloc(dev, sizeof(*axi), GFP_KERNEL); + if (!axi) + return ERR_PTR(-ENOMEM); + + ret = devm_add_action(dev, bt1_axi_clear_data, axi); + if (ret) { + dev_err(dev, "Can't add AXI EHB data clear action\n"); + return ERR_PTR(ret); + } + + axi->dev = dev; + atomic_set(&axi->count, 0); + platform_set_drvdata(pdev, axi); + + return axi; +} + +static int bt1_axi_request_regs(struct bt1_axi *axi) +{ + struct platform_device *pdev = to_platform_device(axi->dev); + struct device *dev = axi->dev; + + axi->sys_regs = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon"); + if (IS_ERR(axi->sys_regs)) { + dev_err(dev, "Couldn't find syscon registers\n"); + return PTR_ERR(axi->sys_regs); + } + + axi->qos_regs = devm_platform_ioremap_resource_byname(pdev, "qos"); + if (IS_ERR(axi->qos_regs)) { + dev_err(dev, "Couldn't map AXI-bus QoS registers\n"); + return PTR_ERR(axi->qos_regs); + } + + return 0; +} + +static int bt1_axi_request_rst(struct bt1_axi *axi) +{ + int ret; + + axi->arst = devm_reset_control_get_optional_exclusive(axi->dev, "arst"); + if (IS_ERR(axi->arst)) { + dev_warn(axi->dev, "Couldn't get reset control line\n"); + return PTR_ERR(axi->arst); + } + + ret = reset_control_deassert(axi->arst); + if (ret) + dev_err(axi->dev, "Failed to deassert the reset line\n"); + + return ret; +} + +static void bt1_axi_disable_clk(void *data) +{ + struct bt1_axi *axi = data; + + clk_disable_unprepare(axi->aclk); +} + +static int bt1_axi_request_clk(struct bt1_axi *axi) +{ + int ret; + + axi->aclk = devm_clk_get(axi->dev, "aclk"); + if (IS_ERR(axi->aclk)) { + dev_err(axi->dev, "Couldn't get AXI Interconnect clock\n"); + return PTR_ERR(axi->aclk); + } + + ret = clk_prepare_enable(axi->aclk); + if (ret) { + dev_err(axi->dev, "Couldn't enable the AXI clock\n"); + return ret; + } + + ret = devm_add_action_or_reset(axi->dev, bt1_axi_disable_clk, axi); + if (ret) { + dev_err(axi->dev, "Can't add AXI clock disable action\n"); + return ret; + } + + return 0; +} + +static int bt1_axi_request_irq(struct bt1_axi *axi) +{ + struct platform_device *pdev = to_platform_device(axi->dev); + int ret; + + axi->irq = platform_get_irq(pdev, 0); + if (axi->irq < 0) + return axi->irq; + + ret = devm_request_irq(axi->dev, axi->irq, bt1_axi_isr, IRQF_SHARED, + "bt1-axi", axi); + if (ret) { + dev_err(axi->dev, "Couldn't request AXI EHB IRQ\n"); + return ret; + } + + return 0; +} + +static ssize_t count_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct bt1_axi *axi = dev_get_drvdata(dev); + + return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&axi->count)); +} +static DEVICE_ATTR_RO(count); + +static ssize_t inject_error_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return scnprintf(buf, PAGE_SIZE, "Error injection: bus unaligned\n"); +} + +static ssize_t inject_error_store(struct device *dev, + struct device_attribute *attr, + const char *data, size_t count) +{ + struct bt1_axi *axi = dev_get_drvdata(dev); + + /* + * Performing unaligned read from the memory will cause the CM2 bus + * error while unaligned writing - the AXI bus write error handled + * by this driver. + */ + if (!strncmp(data, "bus", 3)) + readb(axi->qos_regs); + else if (!strncmp(data, "unaligned", 9)) + writeb(0, axi->qos_regs); + else + return -EINVAL; + + return count; +} +static DEVICE_ATTR_RW(inject_error); + +static struct attribute *bt1_axi_sysfs_attrs[] = { + &dev_attr_count.attr, + &dev_attr_inject_error.attr, + NULL +}; +ATTRIBUTE_GROUPS(bt1_axi_sysfs); + +static void bt1_axi_remove_sysfs(void *data) +{ + struct bt1_axi *axi = data; + + device_remove_groups(axi->dev, bt1_axi_sysfs_groups); +} + +static int bt1_axi_init_sysfs(struct bt1_axi *axi) +{ + int ret; + + ret = device_add_groups(axi->dev, bt1_axi_sysfs_groups); + if (ret) { + dev_err(axi->dev, "Failed to add sysfs files group\n"); + return ret; + } + + ret = devm_add_action_or_reset(axi->dev, bt1_axi_remove_sysfs, axi); + if (ret) + dev_err(axi->dev, "Can't add AXI EHB sysfs remove action\n"); + + return ret; +} + +static int bt1_axi_probe(struct platform_device *pdev) +{ + struct bt1_axi *axi; + int ret; + + axi = bt1_axi_create_data(pdev); + if (IS_ERR(axi)) + return PTR_ERR(axi); + + ret = bt1_axi_request_regs(axi); + if (ret) + return ret; + + ret = bt1_axi_request_rst(axi); + if (ret) + return ret; + + ret = bt1_axi_request_clk(axi); + if (ret) + return ret; + + ret = bt1_axi_request_irq(axi); + if (ret) + return ret; + + ret = bt1_axi_init_sysfs(axi); + if (ret) + return ret; + + return 0; +} + +static const struct of_device_id bt1_axi_of_match[] = { + { .compatible = "baikal,bt1-axi" }, + { } +}; +MODULE_DEVICE_TABLE(of, bt1_axi_of_match); + +static struct platform_driver bt1_axi_driver = { + .probe = bt1_axi_probe, + .driver = { + .name = "bt1-axi", + .of_match_table = bt1_axi_of_match + } +}; +module_platform_driver(bt1_axi_driver); + +MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>"); +MODULE_DESCRIPTION("Baikal-T1 AXI-bus driver"); +MODULE_LICENSE("GPL v2"); |