| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Robert Lippert | 1387 | 94.29% | 2 | 66.67% |
| Patrick Venture | 84 | 5.71% | 1 | 33.33% |
| Total | 1471 | 3 |
/* * Copyright 2017 Google Inc * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Provides a simple driver to control the ASPEED LPC snoop interface which * allows the BMC to listen on and save the data written by * the host to an arbitrary LPC I/O port. * * Typically used by the BMC to "watch" host boot progress via port * 0x80 writes made by the BIOS during the boot process. */ #include <linux/bitops.h> #include <linux/interrupt.h> #include <linux/fs.h> #include <linux/kfifo.h> #include <linux/mfd/syscon.h> #include <linux/miscdevice.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/poll.h> #include <linux/regmap.h> #define DEVICE_NAME "aspeed-lpc-snoop" #define NUM_SNOOP_CHANNELS 2 #define SNOOP_FIFO_SIZE 2048 #define HICR5 0x0 #define HICR5_EN_SNP0W BIT(0) #define HICR5_ENINT_SNP0W BIT(1) #define HICR5_EN_SNP1W BIT(2) #define HICR5_ENINT_SNP1W BIT(3) #define HICR6 0x4 #define HICR6_STR_SNP0W BIT(0) #define HICR6_STR_SNP1W BIT(1) #define SNPWADR 0x10 #define SNPWADR_CH0_MASK GENMASK(15, 0) #define SNPWADR_CH0_SHIFT 0 #define SNPWADR_CH1_MASK GENMASK(31, 16) #define SNPWADR_CH1_SHIFT 16 #define SNPWDR 0x14 #define SNPWDR_CH0_MASK GENMASK(7, 0) #define SNPWDR_CH0_SHIFT 0 #define SNPWDR_CH1_MASK GENMASK(15, 8) #define SNPWDR_CH1_SHIFT 8 #define HICRB 0x80 #define HICRB_ENSNP0D BIT(14) #define HICRB_ENSNP1D BIT(15) struct aspeed_lpc_snoop_model_data { /* The ast2400 has bits 14 and 15 as reserved, whereas the ast2500 * can use them. */ unsigned int has_hicrb_ensnp; }; struct aspeed_lpc_snoop_channel { struct kfifo fifo; wait_queue_head_t wq; struct miscdevice miscdev; }; struct aspeed_lpc_snoop { struct regmap *regmap; int irq; struct aspeed_lpc_snoop_channel chan[NUM_SNOOP_CHANNELS]; }; static struct aspeed_lpc_snoop_channel *snoop_file_to_chan(struct file *file) { return container_of(file->private_data, struct aspeed_lpc_snoop_channel, miscdev); } static ssize_t snoop_file_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) { struct aspeed_lpc_snoop_channel *chan = snoop_file_to_chan(file); unsigned int copied; int ret = 0; if (kfifo_is_empty(&chan->fifo)) { if (file->f_flags & O_NONBLOCK) return -EAGAIN; ret = wait_event_interruptible(chan->wq, !kfifo_is_empty(&chan->fifo)); if (ret == -ERESTARTSYS) return -EINTR; } ret = kfifo_to_user(&chan->fifo, buffer, count, &copied); return ret ? ret : copied; } static unsigned int snoop_file_poll(struct file *file, struct poll_table_struct *pt) { struct aspeed_lpc_snoop_channel *chan = snoop_file_to_chan(file); poll_wait(file, &chan->wq, pt); return !kfifo_is_empty(&chan->fifo) ? POLLIN : 0; } static const struct file_operations snoop_fops = { .owner = THIS_MODULE, .read = snoop_file_read, .poll = snoop_file_poll, .llseek = noop_llseek, }; /* Save a byte to a FIFO and discard the oldest byte if FIFO is full */ static void put_fifo_with_discard(struct aspeed_lpc_snoop_channel *chan, u8 val) { if (!kfifo_initialized(&chan->fifo)) return; if (kfifo_is_full(&chan->fifo)) kfifo_skip(&chan->fifo); kfifo_put(&chan->fifo, val); wake_up_interruptible(&chan->wq); } static irqreturn_t aspeed_lpc_snoop_irq(int irq, void *arg) { struct aspeed_lpc_snoop *lpc_snoop = arg; u32 reg, data; if (regmap_read(lpc_snoop->regmap, HICR6, ®)) return IRQ_NONE; /* Check if one of the snoop channels is interrupting */ reg &= (HICR6_STR_SNP0W | HICR6_STR_SNP1W); if (!reg) return IRQ_NONE; /* Ack pending IRQs */ regmap_write(lpc_snoop->regmap, HICR6, reg); /* Read and save most recent snoop'ed data byte to FIFO */ regmap_read(lpc_snoop->regmap, SNPWDR, &data); if (reg & HICR6_STR_SNP0W) { u8 val = (data & SNPWDR_CH0_MASK) >> SNPWDR_CH0_SHIFT; put_fifo_with_discard(&lpc_snoop->chan[0], val); } if (reg & HICR6_STR_SNP1W) { u8 val = (data & SNPWDR_CH1_MASK) >> SNPWDR_CH1_SHIFT; put_fifo_with_discard(&lpc_snoop->chan[1], val); } return IRQ_HANDLED; } static int aspeed_lpc_snoop_config_irq(struct aspeed_lpc_snoop *lpc_snoop, struct platform_device *pdev) { struct device *dev = &pdev->dev; int rc; lpc_snoop->irq = platform_get_irq(pdev, 0); if (!lpc_snoop->irq) return -ENODEV; rc = devm_request_irq(dev, lpc_snoop->irq, aspeed_lpc_snoop_irq, IRQF_SHARED, DEVICE_NAME, lpc_snoop); if (rc < 0) { dev_warn(dev, "Unable to request IRQ %d\n", lpc_snoop->irq); lpc_snoop->irq = 0; return rc; } return 0; } static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop, struct device *dev, int channel, u16 lpc_port) { int rc = 0; u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en; const struct aspeed_lpc_snoop_model_data *model_data = of_device_get_match_data(dev); init_waitqueue_head(&lpc_snoop->chan[channel].wq); /* Create FIFO datastructure */ rc = kfifo_alloc(&lpc_snoop->chan[channel].fifo, SNOOP_FIFO_SIZE, GFP_KERNEL); if (rc) return rc; lpc_snoop->chan[channel].miscdev.minor = MISC_DYNAMIC_MINOR; lpc_snoop->chan[channel].miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, channel); lpc_snoop->chan[channel].miscdev.fops = &snoop_fops; lpc_snoop->chan[channel].miscdev.parent = dev; rc = misc_register(&lpc_snoop->chan[channel].miscdev); if (rc) return rc; /* Enable LPC snoop channel at requested port */ switch (channel) { case 0: hicr5_en = HICR5_EN_SNP0W | HICR5_ENINT_SNP0W; snpwadr_mask = SNPWADR_CH0_MASK; snpwadr_shift = SNPWADR_CH0_SHIFT; hicrb_en = HICRB_ENSNP0D; break; case 1: hicr5_en = HICR5_EN_SNP1W | HICR5_ENINT_SNP1W; snpwadr_mask = SNPWADR_CH1_MASK; snpwadr_shift = SNPWADR_CH1_SHIFT; hicrb_en = HICRB_ENSNP1D; break; default: return -EINVAL; } regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en); regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask, lpc_port << snpwadr_shift); if (model_data->has_hicrb_ensnp) regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en); return rc; } static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop, int channel) { switch (channel) { case 0: regmap_update_bits(lpc_snoop->regmap, HICR5, HICR5_EN_SNP0W | HICR5_ENINT_SNP0W, 0); break; case 1: regmap_update_bits(lpc_snoop->regmap, HICR5, HICR5_EN_SNP1W | HICR5_ENINT_SNP1W, 0); break; default: return; } kfifo_free(&lpc_snoop->chan[channel].fifo); misc_deregister(&lpc_snoop->chan[channel].miscdev); } static int aspeed_lpc_snoop_probe(struct platform_device *pdev) { struct aspeed_lpc_snoop *lpc_snoop; struct device *dev; u32 port; int rc; dev = &pdev->dev; lpc_snoop = devm_kzalloc(dev, sizeof(*lpc_snoop), GFP_KERNEL); if (!lpc_snoop) return -ENOMEM; lpc_snoop->regmap = syscon_node_to_regmap( pdev->dev.parent->of_node); if (IS_ERR(lpc_snoop->regmap)) { dev_err(dev, "Couldn't get regmap\n"); return -ENODEV; } dev_set_drvdata(&pdev->dev, lpc_snoop); rc = of_property_read_u32_index(dev->of_node, "snoop-ports", 0, &port); if (rc) { dev_err(dev, "no snoop ports configured\n"); return -ENODEV; } rc = aspeed_lpc_snoop_config_irq(lpc_snoop, pdev); if (rc) return rc; rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 0, port); if (rc) return rc; /* Configuration of 2nd snoop channel port is optional */ if (of_property_read_u32_index(dev->of_node, "snoop-ports", 1, &port) == 0) { rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 1, port); if (rc) aspeed_lpc_disable_snoop(lpc_snoop, 0); } return rc; } static int aspeed_lpc_snoop_remove(struct platform_device *pdev) { struct aspeed_lpc_snoop *lpc_snoop = dev_get_drvdata(&pdev->dev); /* Disable both snoop channels */ aspeed_lpc_disable_snoop(lpc_snoop, 0); aspeed_lpc_disable_snoop(lpc_snoop, 1); return 0; } static const struct aspeed_lpc_snoop_model_data ast2400_model_data = { .has_hicrb_ensnp = 0, }; static const struct aspeed_lpc_snoop_model_data ast2500_model_data = { .has_hicrb_ensnp = 1, }; static const struct of_device_id aspeed_lpc_snoop_match[] = { { .compatible = "aspeed,ast2400-lpc-snoop", .data = &ast2400_model_data }, { .compatible = "aspeed,ast2500-lpc-snoop", .data = &ast2500_model_data }, { }, }; static struct platform_driver aspeed_lpc_snoop_driver = { .driver = { .name = DEVICE_NAME, .of_match_table = aspeed_lpc_snoop_match, }, .probe = aspeed_lpc_snoop_probe, .remove = aspeed_lpc_snoop_remove, }; module_platform_driver(aspeed_lpc_snoop_driver); MODULE_DEVICE_TABLE(of, aspeed_lpc_snoop_match); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Robert Lippert <rlippert@google.com>"); MODULE_DESCRIPTION("Linux driver to control Aspeed LPC snoop functionality");
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