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![Serge Semin](/assets/img/avatar_default.png)
There is a ready-to-use method to compare a retrieved from a sysfs node string with another string. It treats both NUL and newline-then-NUL as equivalent string terminations. So use it instead of manually truncating the line length in the strncmp() method. Link: https://lore.kernel.org/r/20200528145050.5203-6-Sergey.Semin@baikalelectronics.ru Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru> Cc: Olof Johansson <olof@lixom.net> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: soc@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
314 lines
7.1 KiB
C
314 lines
7.1 KiB
C
// 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 <Sergey.Semin@baikalelectronics.ru>
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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 <Sergey.Semin@baikalelectronics.ru>");
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MODULE_DESCRIPTION("Baikal-T1 AXI-bus driver");
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MODULE_LICENSE("GPL v2");
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