Hello, I am writing a driver for the leds in PC Engines APU and APU2 boards (see the attachment). There was an attempt at this before (see https://www.spinics.net/lists/linux-leds/msg07904.html), but it was not accepted due to several issues. So I tried to rewrite it completely, using leds-mlxpld.c as a base, and it seems to be working. But I'm getting this oops when trying to rmmod the module: [52615.090143] BUG: unable to handle kernel paging request at ffffc900000c5618 [52615.097435] IP: [<ffffffff811dd099>] ioread32+0x29/0x30 [52615.102835] PGD 11a00e067 [52615.105461] PUD 11a00f067 [52615.108251] PMD 11a014067 [52615.109543] PTE 0 [52615.113072] Oops: 0000 [#1] PREEMPT SMP [52615.117150] Modules linked in: ledtrig_heartbeat arc4 ath10k_pci ath10k_core ath mac80211 crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_ intel leds_apu(-) aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd ccp sdhci_pci sdhci cfg80211 mmc_core led_class sha256_generic sha1_generic rng_core [52615.146823] CPU: 1 PID: 892 Comm: rmmod Not tainted 4.9.47 #37 [52615.152864] Hardware name: PC Engines APU2/APU2, BIOS 4.0.7 02/28/2017 [52615.159656] task: ffff880118538b40 task.stack: ffffc90001480000 [52615.165917] RIP: 0010:[<ffffffff811dd099>] [<ffffffff811dd099>] ioread32+0x29/0x30 [52615.173967] RSP: 0018:ffffc90001483dd0 EFLAGS: 00010292 [52615.179479] RAX: 0000000000000000 RBX: ffff8801185292c8 RCX: 000000018080007d [52615.186933] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffc900000c5618 [52615.194342] RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88011ec0e8c0 [52615.201709] R10: ffff88011a004460 R11: ffff88011a001c00 R12: 0000000000000008 [52615.209057] R13: ffff88011a004440 R14: ffff88011a0042c0 R15: 00000000024ae010 [52615.216527] FS: 00007f665d212700(0000) GS:ffff88011ec80000(0000) knlGS:0000000000000000 [52615.224873] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [52615.230828] CR2: ffffc900000c5618 CR3: 00000001180bc000 CR4: 00000000000406e0 [52615.238273] Stack: [52615.240306] ffffffffa0101023 ffff8801185292c8 ffff8801185293a0 ffffffffa0010076 [52615.248041] ffffc90001483e08 ffff8801185f8010 ffffffff812923c0 ffff88011a312f00 [52615.255846] ffff88011a004460 ffff8801185f8010 ffffffffa01011e8 ffffffff816370e0 [52615.263610] Call Trace: [52615.266136] [<ffffffffa0101023>] ? apu2_led_brightness_set+0x23/0x58 [leds_apu] [52615.273805] [<ffffffffa0010076>] ? led_classdev_unregister+0x46/0xa0 [led_class] [52615.281594] [<ffffffff812923c0>] ? release_nodes+0xf0/0x1b8 [52615.287483] [<ffffffff8128f615>] ? __device_release_driver+0x9d/0x140 [52615.294381] [<ffffffff8128fe41>] ? device_release_driver+0x19/0x28 [52615.300799] [<ffffffff8128eabb>] ? bus_remove_device+0xeb/0x130 [52615.307016] [<ffffffff8128bb79>] ? device_del+0x121/0x258 [52615.312729] [<ffffffff8129158e>] ? platform_device_del+0x1e/0x70 [52615.319110] [<ffffffff812915e9>] ? platform_device_unregister+0x9/0x20 [52615.325925] [<ffffffffa01010b1>] ? apu_led_exit+0xf/0x1b [leds_apu] [52615.332471] [<ffffffff810919dc>] ? SyS_delete_module+0x18c/0x1d0 [52615.338761] [<ffffffff810010b6>] ? exit_to_usermode_loop+0x66/0x70 [52615.345245] [<ffffffff813fb560>] ? entry_SYSCALL_64_fastpath+0x13/0x94 [52615.352092] Code: 40 00 48 81 ff ff ff 03 00 77 20 48 81 ff 00 00 01 00 76 05 0f b7 d7 ed c3 48 c7 c6 fc df 4d 81 e8 35 ff ff ff b8 ff ff ff ff c3 <8b> 07 c3 0f 1f 40 00 48 81 fe ff ff 03 00 48 89 f2 77 1f 48 81 [52615.373340] RIP [<ffffffff811dd099>] ioread32+0x29/0x30 [52615.378891] RSP <ffffc90001483dd0> [52615.382547] CR2: ffffc900000c5618 [52615.385932] ---[ end trace 88328a1715960e7c ]--- [52615.390731] note: rmmod[892] exited with preempt_count 1 Any ideas and recommendations would be greatly appreciated. Best regards, Alan
/* * drivers/leds/leds-apu.c * Copyright (C) 2017 Alan Mizrahi, alan at mizrahi dot com dot ve * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the names of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include <linux/dmi.h> #include <linux/err.h> #include <linux/init.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/leds.h> #include <linux/module.h> #include <linux/platform_device.h> #define APU1_FCH_ACPI_MMIO_BASE 0xFED80000 #define APU1_FCH_GPIO_BASE (APU1_FCH_ACPI_MMIO_BASE + 0x1BD) #define APU1_LEDON 0x08 #define APU1_LEDOFF 0xC8 #define APU1_NUM_GPIO 3 #define APU1_IOSIZE sizeof(u8) #define APU2_FCH_ACPI_MMIO_BASE 0xFED80000 #define APU2_FCH_GPIO_BASE (APU2_FCH_ACPI_MMIO_BASE + 0x1500) #define APU2_GPIO_BIT_WRITE 22 #define APU2_APU2_NUM_GPIO 4 #define APU2_IOSIZE sizeof(u32) /* LED access parameters */ struct apu_param { void __iomem *addr; /* for ioread/iowrite */ }; /* LED private data */ struct apu_led_priv { struct led_classdev cdev; struct apu_param param; }; #define cdev_to_priv(c) container_of(c, struct apu_led_priv, cdev) /* LED profile */ struct apu_led_profile { const char *name; enum led_brightness brightness; unsigned long offset; /* for devm_ioremap */ }; /* Supported platform types */ enum apu_led_platform_types { LED_PLATFORM_APU1, LED_PLATFORM_APU2, }; struct apu_led_pdata { struct platform_device *pdev; struct apu_led_priv *pled; struct apu_led_profile *profile; enum apu_led_platform_types platform; int num_led_instances; int iosize; /* for devm_ioremap() */ spinlock_t lock; }; static struct apu_led_pdata *apu_led; static struct apu_led_profile apu1_led_profile[] = { { "apu:1", 1, APU1_FCH_GPIO_BASE + 0 * APU1_IOSIZE }, { "apu:2", LED_OFF, APU1_FCH_GPIO_BASE + 1 * APU1_IOSIZE }, { "apu:3", LED_OFF, APU1_FCH_GPIO_BASE + 2 * APU1_IOSIZE }, }; static struct apu_led_profile apu2_led_profile[] = { { "apu2:1", 1, APU2_FCH_GPIO_BASE + 68 * APU2_IOSIZE }, { "apu2:2", LED_OFF, APU2_FCH_GPIO_BASE + 69 * APU2_IOSIZE }, { "apu2:3", LED_OFF, APU2_FCH_GPIO_BASE + 70 * APU2_IOSIZE }, }; static struct dmi_system_id apu_led_dmi_table[] __initdata = { { .ident = "apu", .matches = { DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"), DMI_MATCH(DMI_PRODUCT_NAME, "APU") } }, { .ident = "apu2", .matches = { DMI_MATCH(DMI_SYS_VENDOR, "PC Engines"), DMI_MATCH(DMI_BOARD_NAME, "APU2") } }, {} }; MODULE_DEVICE_TABLE(dmi, apu_led_dmi_table); static void apu1_led_brightness_set(struct led_classdev *led, enum led_brightness value) { struct apu_led_priv *pled = cdev_to_priv(led); spin_lock(&apu_led->lock); iowrite8(value ? APU1_LEDON : APU1_LEDOFF, pled->param.addr); spin_unlock(&apu_led->lock); return; } static void apu2_led_brightness_set(struct led_classdev *led, enum led_brightness value) { struct apu_led_priv *pled = cdev_to_priv(led); u32 value_new; spin_lock(&apu_led->lock); value_new = ioread32(pled->param.addr); if (value) value_new &= ~BIT(APU2_GPIO_BIT_WRITE); else value_new |= BIT(APU2_GPIO_BIT_WRITE); iowrite32(value_new, pled->param.addr); spin_unlock(&apu_led->lock); return; } /* * Does the hardware support this? * static int apu1_led_blink_set(struct led_classdev *led, unsigned long *delay_on, unsigned long *delay_off) { struct apu_led_priv *pled = cdev_to_priv(led); return 0; } static int apu2_led_blink_set(struct led_classdev *led, unsigned long *delay_on, unsigned long *delay_off) { struct apu_led_priv *pled = cdev_to_priv(led); return 0; } */ static int apu_led_config(struct device *dev, struct apu_led_pdata *apuld) { int i; int err; apu_led->pled = devm_kzalloc(dev, sizeof(struct apu_led_priv) * apu_led->num_led_instances, GFP_KERNEL); if (!apu_led->pled) return -ENOMEM; for (i = 0; i < apu_led->num_led_instances; i++) { apu_led->pled[i].cdev.name = apu_led->profile[i].name; apu_led->pled[i].cdev.brightness = apu_led->profile[i].brightness; apu_led->pled[i].cdev.max_brightness = 1; if (apu_led->platform == LED_PLATFORM_APU1) { apu_led->pled[i].cdev.brightness_set = apu1_led_brightness_set; /* apu_led->pled[i].cdev.blink_set = apu1_led_blink_set; */ } else if (apu_led->platform == LED_PLATFORM_APU2) { apu_led->pled[i].cdev.brightness_set = apu2_led_brightness_set; /* apu_led->pled[i].cdev.blink_set = apu2_led_blink_set; */ } apu_led->pled[i].cdev.flags = LED_CORE_SUSPENDRESUME; err = devm_led_classdev_register(dev, &apu_led->pled[i].cdev); if (err) return err; apu_led->pled[i].param.addr = devm_ioremap(dev, apu_led->profile[i].offset, apu_led->iosize); if (!apu_led->pled[i].param.addr) return -ENOMEM; if (apu_led->profile[i].brightness) apu_led->pled[i].cdev.brightness_set(&apu_led->pled[i].cdev, apu_led->profile[i].brightness); } return 0; } static int __init apu_led_probe(struct platform_device *pdev) { apu_led = devm_kzalloc(&pdev->dev, sizeof(*apu_led), GFP_KERNEL); if (!apu_led) return -ENOMEM; apu_led->pdev = pdev; if (dmi_match(DMI_BOARD_NAME, "APU")) { apu_led->profile = apu1_led_profile; apu_led->platform = LED_PLATFORM_APU1; apu_led->num_led_instances = ARRAY_SIZE(apu1_led_profile); apu_led->iosize = APU1_IOSIZE; } else if (dmi_match(DMI_BOARD_NAME, "APU2")) { apu_led->profile = apu2_led_profile; apu_led->platform = LED_PLATFORM_APU2; apu_led->num_led_instances = ARRAY_SIZE(apu2_led_profile); apu_led->iosize = APU2_IOSIZE; } spin_lock_init(&apu_led->lock); return apu_led_config(&pdev->dev, apu_led); } static struct platform_driver apu_led_driver = { .driver = { .name = KBUILD_MODNAME, }, }; static int __init apu_led_init(void) { struct platform_device *pdev; int err; if (!dmi_match(DMI_SYS_VENDOR, "PC Engines")) { pr_err("No PC Engines board detected\n"); return -ENODEV; } if (!(dmi_match(DMI_PRODUCT_NAME, "APU") || dmi_match(DMI_PRODUCT_NAME, "APU2"))) { printk(KERN_ERR "Unknown PC Engines board: %s\n", dmi_get_system_info(DMI_PRODUCT_NAME)); return -ENODEV; } pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0); if (IS_ERR(pdev)) { pr_err("Device allocation failed\n"); return PTR_ERR(pdev); } err = platform_driver_probe(&apu_led_driver, apu_led_probe); if (err) { pr_err("Probe platform driver failed\n"); platform_device_unregister(pdev); } return err; } static void __exit apu_led_exit(void) { platform_device_unregister(apu_led->pdev); platform_driver_unregister(&apu_led_driver); } module_init(apu_led_init); module_exit(apu_led_exit); MODULE_AUTHOR("Alan Mizrahi, alan at mizrahi dot com dot ve"); MODULE_DESCRIPTION("PC Engines APU family LED driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:leds_apu");