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314 lines
7.1 KiB
314 lines
7.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2020 BAIKAL ELECTRONICS, JSC |
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* |
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* Authors: |
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* Serge Semin <[email protected]> |
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* |
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* Baikal-T1 AXI-bus driver |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/bitfield.h> |
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#include <linux/device.h> |
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#include <linux/atomic.h> |
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#include <linux/regmap.h> |
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#include <linux/platform_device.h> |
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#include <linux/mfd/syscon.h> |
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#include <linux/interrupt.h> |
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#include <linux/io.h> |
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#include <linux/nmi.h> |
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#include <linux/of.h> |
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#include <linux/clk.h> |
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#include <linux/reset.h> |
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#include <linux/sysfs.h> |
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#define BT1_AXI_WERRL 0x110 |
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#define BT1_AXI_WERRH 0x114 |
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#define BT1_AXI_WERRH_TYPE BIT(23) |
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#define BT1_AXI_WERRH_ADDR_FLD 24 |
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#define BT1_AXI_WERRH_ADDR_MASK GENMASK(31, BT1_AXI_WERRH_ADDR_FLD) |
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/* |
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* struct bt1_axi - Baikal-T1 AXI-bus private data |
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* @dev: Pointer to the device structure. |
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* @qos_regs: AXI Interconnect QoS tuning registers. |
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* @sys_regs: Baikal-T1 System Controller registers map. |
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* @irq: Errors IRQ number. |
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* @aclk: AXI reference clock. |
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* @arst: AXI Interconnect reset line. |
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* @count: Number of errors detected. |
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*/ |
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struct bt1_axi { |
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struct device *dev; |
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void __iomem *qos_regs; |
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struct regmap *sys_regs; |
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int irq; |
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struct clk *aclk; |
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struct reset_control *arst; |
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atomic_t count; |
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}; |
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static irqreturn_t bt1_axi_isr(int irq, void *data) |
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{ |
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struct bt1_axi *axi = data; |
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u32 low = 0, high = 0; |
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regmap_read(axi->sys_regs, BT1_AXI_WERRL, &low); |
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regmap_read(axi->sys_regs, BT1_AXI_WERRH, &high); |
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dev_crit_ratelimited(axi->dev, |
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"AXI-bus fault %d: %s at 0x%x%08x\n", |
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atomic_inc_return(&axi->count), |
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high & BT1_AXI_WERRH_TYPE ? "no slave" : "slave protocol error", |
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high, low); |
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/* |
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* Print backtrace on each CPU. This might be pointless if the fault |
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* has happened on the same CPU as the IRQ handler is executed or |
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* the other core proceeded further execution despite the error. |
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* But if it's not, by looking at the trace we would get straight to |
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* the cause of the problem. |
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*/ |
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trigger_all_cpu_backtrace(); |
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return IRQ_HANDLED; |
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} |
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static void bt1_axi_clear_data(void *data) |
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{ |
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struct bt1_axi *axi = data; |
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struct platform_device *pdev = to_platform_device(axi->dev); |
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platform_set_drvdata(pdev, NULL); |
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} |
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static struct bt1_axi *bt1_axi_create_data(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct bt1_axi *axi; |
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int ret; |
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axi = devm_kzalloc(dev, sizeof(*axi), GFP_KERNEL); |
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if (!axi) |
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return ERR_PTR(-ENOMEM); |
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ret = devm_add_action(dev, bt1_axi_clear_data, axi); |
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if (ret) { |
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dev_err(dev, "Can't add AXI EHB data clear action\n"); |
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return ERR_PTR(ret); |
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} |
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axi->dev = dev; |
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atomic_set(&axi->count, 0); |
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platform_set_drvdata(pdev, axi); |
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return axi; |
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} |
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static int bt1_axi_request_regs(struct bt1_axi *axi) |
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{ |
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struct platform_device *pdev = to_platform_device(axi->dev); |
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struct device *dev = axi->dev; |
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axi->sys_regs = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon"); |
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if (IS_ERR(axi->sys_regs)) { |
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dev_err(dev, "Couldn't find syscon registers\n"); |
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return PTR_ERR(axi->sys_regs); |
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} |
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axi->qos_regs = devm_platform_ioremap_resource_byname(pdev, "qos"); |
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if (IS_ERR(axi->qos_regs)) |
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dev_err(dev, "Couldn't map AXI-bus QoS registers\n"); |
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return PTR_ERR_OR_ZERO(axi->qos_regs); |
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} |
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static int bt1_axi_request_rst(struct bt1_axi *axi) |
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{ |
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int ret; |
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axi->arst = devm_reset_control_get_optional_exclusive(axi->dev, "arst"); |
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if (IS_ERR(axi->arst)) { |
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dev_warn(axi->dev, "Couldn't get reset control line\n"); |
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return PTR_ERR(axi->arst); |
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} |
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ret = reset_control_deassert(axi->arst); |
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if (ret) |
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dev_err(axi->dev, "Failed to deassert the reset line\n"); |
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return ret; |
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} |
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static void bt1_axi_disable_clk(void *data) |
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{ |
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struct bt1_axi *axi = data; |
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clk_disable_unprepare(axi->aclk); |
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} |
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static int bt1_axi_request_clk(struct bt1_axi *axi) |
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{ |
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int ret; |
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axi->aclk = devm_clk_get(axi->dev, "aclk"); |
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if (IS_ERR(axi->aclk)) { |
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dev_err(axi->dev, "Couldn't get AXI Interconnect clock\n"); |
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return PTR_ERR(axi->aclk); |
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} |
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ret = clk_prepare_enable(axi->aclk); |
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if (ret) { |
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dev_err(axi->dev, "Couldn't enable the AXI clock\n"); |
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return ret; |
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} |
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ret = devm_add_action_or_reset(axi->dev, bt1_axi_disable_clk, axi); |
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if (ret) |
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dev_err(axi->dev, "Can't add AXI clock disable action\n"); |
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return ret; |
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} |
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static int bt1_axi_request_irq(struct bt1_axi *axi) |
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{ |
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struct platform_device *pdev = to_platform_device(axi->dev); |
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int ret; |
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axi->irq = platform_get_irq(pdev, 0); |
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if (axi->irq < 0) |
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return axi->irq; |
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ret = devm_request_irq(axi->dev, axi->irq, bt1_axi_isr, IRQF_SHARED, |
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"bt1-axi", axi); |
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if (ret) |
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dev_err(axi->dev, "Couldn't request AXI EHB IRQ\n"); |
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return ret; |
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} |
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static ssize_t count_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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struct bt1_axi *axi = dev_get_drvdata(dev); |
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return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&axi->count)); |
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} |
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static DEVICE_ATTR_RO(count); |
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static ssize_t inject_error_show(struct device *dev, |
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struct device_attribute *attr, char *buf) |
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{ |
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return scnprintf(buf, PAGE_SIZE, "Error injection: bus unaligned\n"); |
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} |
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static ssize_t inject_error_store(struct device *dev, |
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struct device_attribute *attr, |
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const char *data, size_t count) |
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{ |
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struct bt1_axi *axi = dev_get_drvdata(dev); |
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/* |
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* Performing unaligned read from the memory will cause the CM2 bus |
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* error while unaligned writing - the AXI bus write error handled |
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* by this driver. |
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*/ |
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if (sysfs_streq(data, "bus")) |
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readb(axi->qos_regs); |
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else if (sysfs_streq(data, "unaligned")) |
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writeb(0, axi->qos_regs); |
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else |
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return -EINVAL; |
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return count; |
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} |
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static DEVICE_ATTR_RW(inject_error); |
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static struct attribute *bt1_axi_sysfs_attrs[] = { |
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&dev_attr_count.attr, |
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&dev_attr_inject_error.attr, |
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NULL |
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}; |
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ATTRIBUTE_GROUPS(bt1_axi_sysfs); |
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static void bt1_axi_remove_sysfs(void *data) |
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{ |
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struct bt1_axi *axi = data; |
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device_remove_groups(axi->dev, bt1_axi_sysfs_groups); |
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} |
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static int bt1_axi_init_sysfs(struct bt1_axi *axi) |
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{ |
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int ret; |
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ret = device_add_groups(axi->dev, bt1_axi_sysfs_groups); |
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if (ret) { |
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dev_err(axi->dev, "Failed to add sysfs files group\n"); |
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return ret; |
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} |
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ret = devm_add_action_or_reset(axi->dev, bt1_axi_remove_sysfs, axi); |
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if (ret) |
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dev_err(axi->dev, "Can't add AXI EHB sysfs remove action\n"); |
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return ret; |
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} |
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static int bt1_axi_probe(struct platform_device *pdev) |
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{ |
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struct bt1_axi *axi; |
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int ret; |
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axi = bt1_axi_create_data(pdev); |
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if (IS_ERR(axi)) |
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return PTR_ERR(axi); |
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ret = bt1_axi_request_regs(axi); |
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if (ret) |
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return ret; |
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ret = bt1_axi_request_rst(axi); |
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if (ret) |
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return ret; |
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ret = bt1_axi_request_clk(axi); |
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if (ret) |
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return ret; |
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ret = bt1_axi_request_irq(axi); |
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if (ret) |
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return ret; |
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ret = bt1_axi_init_sysfs(axi); |
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if (ret) |
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return ret; |
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return 0; |
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} |
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static const struct of_device_id bt1_axi_of_match[] = { |
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{ .compatible = "baikal,bt1-axi" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, bt1_axi_of_match); |
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static struct platform_driver bt1_axi_driver = { |
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.probe = bt1_axi_probe, |
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.driver = { |
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.name = "bt1-axi", |
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.of_match_table = bt1_axi_of_match |
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} |
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}; |
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module_platform_driver(bt1_axi_driver); |
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MODULE_AUTHOR("Serge Semin <[email protected]>"); |
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MODULE_DESCRIPTION("Baikal-T1 AXI-bus driver"); |
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MODULE_LICENSE("GPL v2");
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