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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 | // 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 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)) return dev_err_probe(axi->dev, PTR_ERR(axi->aclk), "Couldn't get AXI Interconnect clock\n"); 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; } 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"); |