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Diffstat (limited to 'drivers/misc/aspeed-lpc-snoop.c')
-rw-r--r--drivers/misc/aspeed-lpc-snoop.c349
1 files changed, 0 insertions, 349 deletions
diff --git a/drivers/misc/aspeed-lpc-snoop.c b/drivers/misc/aspeed-lpc-snoop.c
deleted file mode 100644
index 2feb4347d67f..000000000000
--- a/drivers/misc/aspeed-lpc-snoop.c
+++ /dev/null
@@ -1,349 +0,0 @@
-/*
- * 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, &reg))
- 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");
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-22 02:16:58 +0300