+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
- *
- * Authors:
- * Serge Semin <Sergey.Semin@baikalelectronics.ru>
- *
- * Baikal-T1 APB-bus driver
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/device.h>
-#include <linux/atomic.h>
-#include <linux/platform_device.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/nmi.h>
-#include <linux/of.h>
-#include <linux/regmap.h>
-#include <linux/clk.h>
-#include <linux/reset.h>
-#include <linux/time64.h>
-#include <linux/sysfs.h>
-
-#define APB_EHB_ISR 0x00
-#define APB_EHB_ISR_PENDING BIT(0)
-#define APB_EHB_ISR_MASK BIT(1)
-#define APB_EHB_ADDR 0x04
-#define APB_EHB_TIMEOUT 0x08
-
-#define APB_EHB_TIMEOUT_MIN 0x000003FFU
-#define APB_EHB_TIMEOUT_MAX 0xFFFFFFFFU
-
-/*
- * struct bt1_apb - Baikal-T1 APB EHB private data
- * @dev: Pointer to the device structure.
- * @regs: APB EHB registers map.
- * @res: No-device error injection memory region.
- * @irq: Errors IRQ number.
- * @rate: APB-bus reference clock rate.
- * @pclk: APB-reference clock.
- * @prst: APB domain reset line.
- * @count: Number of errors detected.
- */
-struct bt1_apb {
- struct device *dev;
-
- struct regmap *regs;
- void __iomem *res;
- int irq;
-
- unsigned long rate;
- struct clk *pclk;
-
- struct reset_control *prst;
-
- atomic_t count;
-};
-
-static const struct regmap_config bt1_apb_regmap_cfg = {
- .reg_bits = 32,
- .val_bits = 32,
- .reg_stride = 4,
- .max_register = APB_EHB_TIMEOUT,
- .fast_io = true
-};
-
-static inline unsigned long bt1_apb_n_to_timeout_us(struct bt1_apb *apb, u32 n)
-{
- u64 timeout = (u64)n * USEC_PER_SEC;
-
- do_div(timeout, apb->rate);
-
- return timeout;
-
-}
-
-static inline unsigned long bt1_apb_timeout_to_n_us(struct bt1_apb *apb,
- unsigned long timeout)
-{
- u64 n = (u64)timeout * apb->rate;
-
- do_div(n, USEC_PER_SEC);
-
- return n;
-
-}
-
-static irqreturn_t bt1_apb_isr(int irq, void *data)
-{
- struct bt1_apb *apb = data;
- u32 addr = 0;
-
- regmap_read(apb->regs, APB_EHB_ADDR, &addr);
-
- dev_crit_ratelimited(apb->dev,
- "APB-bus fault %d: Slave access timeout at 0x%08x\n",
- atomic_inc_return(&apb->count),
- addr);
-
- /*
- * 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();
-
- regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING, 0);
-
- return IRQ_HANDLED;
-}
-
-static void bt1_apb_clear_data(void *data)
-{
- struct bt1_apb *apb = data;
- struct platform_device *pdev = to_platform_device(apb->dev);
-
- platform_set_drvdata(pdev, NULL);
-}
-
-static struct bt1_apb *bt1_apb_create_data(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct bt1_apb *apb;
- int ret;
-
- apb = devm_kzalloc(dev, sizeof(*apb), GFP_KERNEL);
- if (!apb)
- return ERR_PTR(-ENOMEM);
-
- ret = devm_add_action(dev, bt1_apb_clear_data, apb);
- if (ret) {
- dev_err(dev, "Can't add APB EHB data clear action\n");
- return ERR_PTR(ret);
- }
-
- apb->dev = dev;
- atomic_set(&apb->count, 0);
- platform_set_drvdata(pdev, apb);
-
- return apb;
-}
-
-static int bt1_apb_request_regs(struct bt1_apb *apb)
-{
- struct platform_device *pdev = to_platform_device(apb->dev);
- void __iomem *regs;
-
- regs = devm_platform_ioremap_resource_byname(pdev, "ehb");
- if (IS_ERR(regs)) {
- dev_err(apb->dev, "Couldn't map APB EHB registers\n");
- return PTR_ERR(regs);
- }
-
- apb->regs = devm_regmap_init_mmio(apb->dev, regs, &bt1_apb_regmap_cfg);
- if (IS_ERR(apb->regs)) {
- dev_err(apb->dev, "Couldn't create APB EHB regmap\n");
- return PTR_ERR(apb->regs);
- }
-
- apb->res = devm_platform_ioremap_resource_byname(pdev, "nodev");
- if (IS_ERR(apb->res))
- dev_err(apb->dev, "Couldn't map reserved region\n");
-
- return PTR_ERR_OR_ZERO(apb->res);
-}
-
-static int bt1_apb_request_rst(struct bt1_apb *apb)
-{
- int ret;
-
- apb->prst = devm_reset_control_get_optional_exclusive(apb->dev, "prst");
- if (IS_ERR(apb->prst))
- return dev_err_probe(apb->dev, PTR_ERR(apb->prst),
- "Couldn't get reset control line\n");
-
- ret = reset_control_deassert(apb->prst);
- if (ret)
- dev_err(apb->dev, "Failed to deassert the reset line\n");
-
- return ret;
-}
-
-static int bt1_apb_request_clk(struct bt1_apb *apb)
-{
- apb->pclk = devm_clk_get_enabled(apb->dev, "pclk");
- if (IS_ERR(apb->pclk))
- return dev_err_probe(apb->dev, PTR_ERR(apb->pclk),
- "Couldn't get APB clock descriptor\n");
-
- apb->rate = clk_get_rate(apb->pclk);
- if (!apb->rate) {
- dev_err(apb->dev, "Invalid clock rate\n");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static void bt1_apb_clear_irq(void *data)
-{
- struct bt1_apb *apb = data;
-
- regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_MASK, 0);
-}
-
-static int bt1_apb_request_irq(struct bt1_apb *apb)
-{
- struct platform_device *pdev = to_platform_device(apb->dev);
- int ret;
-
- apb->irq = platform_get_irq(pdev, 0);
- if (apb->irq < 0)
- return apb->irq;
-
- ret = devm_request_irq(apb->dev, apb->irq, bt1_apb_isr, IRQF_SHARED,
- "bt1-apb", apb);
- if (ret) {
- dev_err(apb->dev, "Couldn't request APB EHB IRQ\n");
- return ret;
- }
-
- ret = devm_add_action(apb->dev, bt1_apb_clear_irq, apb);
- if (ret) {
- dev_err(apb->dev, "Can't add APB EHB IRQs clear action\n");
- return ret;
- }
-
- /* Unmask IRQ and clear it' pending flag. */
- regmap_update_bits(apb->regs, APB_EHB_ISR,
- APB_EHB_ISR_PENDING | APB_EHB_ISR_MASK,
- APB_EHB_ISR_MASK);
-
- return 0;
-}
-
-static ssize_t count_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct bt1_apb *apb = dev_get_drvdata(dev);
-
- return scnprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&apb->count));
-}
-static DEVICE_ATTR_RO(count);
-
-static ssize_t timeout_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct bt1_apb *apb = dev_get_drvdata(dev);
- unsigned long timeout;
- int ret;
- u32 n;
-
- ret = regmap_read(apb->regs, APB_EHB_TIMEOUT, &n);
- if (ret)
- return ret;
-
- timeout = bt1_apb_n_to_timeout_us(apb, n);
-
- return scnprintf(buf, PAGE_SIZE, "%lu\n", timeout);
-}
-
-static ssize_t timeout_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct bt1_apb *apb = dev_get_drvdata(dev);
- unsigned long timeout;
- int ret;
- u32 n;
-
- if (kstrtoul(buf, 0, &timeout) < 0)
- return -EINVAL;
-
- n = bt1_apb_timeout_to_n_us(apb, timeout);
- n = clamp(n, APB_EHB_TIMEOUT_MIN, APB_EHB_TIMEOUT_MAX);
-
- ret = regmap_write(apb->regs, APB_EHB_TIMEOUT, n);
-
- return ret ?: count;
-}
-static DEVICE_ATTR_RW(timeout);
-
-static ssize_t inject_error_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return scnprintf(buf, PAGE_SIZE, "Error injection: nodev irq\n");
-}
-
-static ssize_t inject_error_store(struct device *dev,
- struct device_attribute *attr,
- const char *data, size_t count)
-{
- struct bt1_apb *apb = dev_get_drvdata(dev);
-
- /*
- * Either dummy read from the unmapped address in the APB IO area
- * or manually set the IRQ status.
- */
- if (sysfs_streq(data, "nodev"))
- readl(apb->res);
- else if (sysfs_streq(data, "irq"))
- regmap_update_bits(apb->regs, APB_EHB_ISR, APB_EHB_ISR_PENDING,
- APB_EHB_ISR_PENDING);
- else
- return -EINVAL;
-
- return count;
-}
-static DEVICE_ATTR_RW(inject_error);
-
-static struct attribute *bt1_apb_sysfs_attrs[] = {
- &dev_attr_count.attr,
- &dev_attr_timeout.attr,
- &dev_attr_inject_error.attr,
- NULL
-};
-ATTRIBUTE_GROUPS(bt1_apb_sysfs);
-
-static void bt1_apb_remove_sysfs(void *data)
-{
- struct bt1_apb *apb = data;
-
- device_remove_groups(apb->dev, bt1_apb_sysfs_groups);
-}
-
-static int bt1_apb_init_sysfs(struct bt1_apb *apb)
-{
- int ret;
-
- ret = device_add_groups(apb->dev, bt1_apb_sysfs_groups);
- if (ret) {
- dev_err(apb->dev, "Failed to create EHB APB sysfs nodes\n");
- return ret;
- }
-
- ret = devm_add_action_or_reset(apb->dev, bt1_apb_remove_sysfs, apb);
- if (ret)
- dev_err(apb->dev, "Can't add APB EHB sysfs remove action\n");
-
- return ret;
-}
-
-static int bt1_apb_probe(struct platform_device *pdev)
-{
- struct bt1_apb *apb;
- int ret;
-
- apb = bt1_apb_create_data(pdev);
- if (IS_ERR(apb))
- return PTR_ERR(apb);
-
- ret = bt1_apb_request_regs(apb);
- if (ret)
- return ret;
-
- ret = bt1_apb_request_rst(apb);
- if (ret)
- return ret;
-
- ret = bt1_apb_request_clk(apb);
- if (ret)
- return ret;
-
- ret = bt1_apb_request_irq(apb);
- if (ret)
- return ret;
-
- ret = bt1_apb_init_sysfs(apb);
- if (ret)
- return ret;
-
- return 0;
-}
-
-static const struct of_device_id bt1_apb_of_match[] = {
- { .compatible = "baikal,bt1-apb" },
- { }
-};
-MODULE_DEVICE_TABLE(of, bt1_apb_of_match);
-
-static struct platform_driver bt1_apb_driver = {
- .probe = bt1_apb_probe,
- .driver = {
- .name = "bt1-apb",
- .of_match_table = bt1_apb_of_match
- }
-};
-module_platform_driver(bt1_apb_driver);
-
-MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>");
-MODULE_DESCRIPTION("Baikal-T1 APB-bus driver");
+++ /dev/null
-// 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_OR_ZERO(axi->qos_regs);
-}
-
-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))
- return dev_err_probe(axi->dev, PTR_ERR(axi->arst),
- "Couldn't get reset control line\n");
-
- ret = reset_control_deassert(axi->arst);
- if (ret)
- dev_err(axi->dev, "Failed to deassert the reset line\n");
-
- return ret;
-}
-
-static int bt1_axi_request_clk(struct bt1_axi *axi)
-{
- axi->aclk = devm_clk_get_enabled(axi->dev, "aclk");
- if (IS_ERR(axi->aclk))
- return dev_err_probe(axi->dev, PTR_ERR(axi->aclk),
- "Couldn't get AXI Interconnect clock\n");
-
- 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;
-}
-
-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 (sysfs_streq(data, "bus"))
- readb(axi->qos_regs);
- else if (sysfs_streq(data, "unaligned"))
- 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");
projects / thirdparty / kernel / stable.git / commitdiff
