[PATCH] aspeed-lpc-snoop: add 16-bit POST code support
Joel Stanley
joel at jms.id.au
Tue Nov 16 20:09:44 PST 2021
Hi Govert,
On Wed, 24 Feb 2021 at 09:07, Govert Overgaauw
<govert.overgaauw at prodrive-technologies.com> wrote:
>
> Intel coffeelake plattform uses a 16-bit POST code format instead of 8-bit. Add
> a third FIFO for storing the combined 16-bit post codes.
Thanks for the patch. It slipped through the cracks. I would like to
merge it if we could get some review and/or testing.
Ryan, Zev, Oskar, Lei: please jump in if you're able to help.
Cheers,
Joel
>
> Signed-off-by: Govert Overgaauw <govert.overgaauw at prodrive-technologies.com>
> ---
> drivers/soc/aspeed/aspeed-lpc-snoop.c | 117 +++++++++++++++++---------
> 1 file changed, 79 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> index 682ba0eb4eba..40d113d253fc 100644
> --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> @@ -58,7 +58,7 @@ struct aspeed_lpc_snoop_model_data {
> unsigned int has_hicrb_ensnp;
> };
>
> -struct aspeed_lpc_snoop_channel {
> +struct aspeed_lpc_snoop_fifo {
> struct kfifo fifo;
> wait_queue_head_t wq;
> struct miscdevice miscdev;
> @@ -67,32 +67,39 @@ struct aspeed_lpc_snoop_channel {
> struct aspeed_lpc_snoop {
> struct regmap *regmap;
> int irq;
> - struct aspeed_lpc_snoop_channel chan[NUM_SNOOP_CHANNELS];
> + struct aspeed_lpc_snoop_fifo chan[NUM_SNOOP_CHANNELS];
> +
> + /*
> + * 16-bit postcodes are combination
> + * of both channels written to a seperate device file, because
> + * both bytes have to be added on the same interrupt.
> + */
> + struct aspeed_lpc_snoop_fifo combined;
> };
>
> -static struct aspeed_lpc_snoop_channel *snoop_file_to_chan(struct file *file)
> +static struct aspeed_lpc_snoop_fifo *snoop_file_to_fifo(struct file *file)
> {
> return container_of(file->private_data,
> - struct aspeed_lpc_snoop_channel,
> + struct aspeed_lpc_snoop_fifo,
> 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);
> + struct aspeed_lpc_snoop_fifo *fifo = snoop_file_to_fifo(file);
> unsigned int copied;
> int ret = 0;
>
> - if (kfifo_is_empty(&chan->fifo)) {
> + if (kfifo_is_empty(&fifo->fifo)) {
> if (file->f_flags & O_NONBLOCK)
> return -EAGAIN;
> - ret = wait_event_interruptible(chan->wq,
> - !kfifo_is_empty(&chan->fifo));
> + ret = wait_event_interruptible(fifo->wq,
> + !kfifo_is_empty(&fifo->fifo));
> if (ret == -ERESTARTSYS)
> return -EINTR;
> }
> - ret = kfifo_to_user(&chan->fifo, buffer, count, &copied);
> + ret = kfifo_to_user(&fifo->fifo, buffer, count, &copied);
>
> return ret ? ret : copied;
> }
> @@ -100,10 +107,10 @@ static ssize_t snoop_file_read(struct file *file, char __user *buffer,
> static __poll_t snoop_file_poll(struct file *file,
> struct poll_table_struct *pt)
> {
> - struct aspeed_lpc_snoop_channel *chan = snoop_file_to_chan(file);
> + struct aspeed_lpc_snoop_fifo *fifo = snoop_file_to_fifo(file);
>
> - poll_wait(file, &chan->wq, pt);
> - return !kfifo_is_empty(&chan->fifo) ? EPOLLIN : 0;
> + poll_wait(file, &fifo->wq, pt);
> + return !kfifo_is_empty(&fifo->fifo) ? EPOLLIN : 0;
> }
>
> static const struct file_operations snoop_fops = {
> @@ -113,21 +120,22 @@ static const struct file_operations snoop_fops = {
> .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)
> +/* Save data to a FIFO and discard the oldest byte if FIFO is full */
> +static void put_fifo_with_discard(struct aspeed_lpc_snoop_fifo *fifo, size_t len, u8 *buf)
> {
> - if (!kfifo_initialized(&chan->fifo))
> + if (!kfifo_initialized(&fifo->fifo))
> return;
> - if (kfifo_is_full(&chan->fifo))
> - kfifo_skip(&chan->fifo);
> - kfifo_put(&chan->fifo, val);
> - wake_up_interruptible(&chan->wq);
> + if (kfifo_is_full(&fifo->fifo))
> + kfifo_skip(&fifo->fifo);
> + kfifo_in(&fifo->fifo, buf, len);
> + wake_up_interruptible(&fifo->wq);
> }
>
> static irqreturn_t aspeed_lpc_snoop_irq(int irq, void *arg)
> {
> struct aspeed_lpc_snoop *lpc_snoop = arg;
> u32 reg, data;
> + u16 postval = 0;
>
> if (regmap_read(lpc_snoop->regmap, HICR6, ®))
> return IRQ_NONE;
> @@ -140,20 +148,25 @@ static irqreturn_t aspeed_lpc_snoop_irq(int irq, void *arg)
> /* Ack pending IRQs */
> regmap_write(lpc_snoop->regmap, HICR6, reg);
>
> - /* Read and save most recent snoop'ed data byte to FIFO */
> + /* Read and save most recent snoop'ed data byte(s) 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);
> + put_fifo_with_discard(&lpc_snoop->chan[0], sizeof(val), &val);
> + postval |= val;
> }
> if (reg & HICR6_STR_SNP1W) {
> u8 val = (data & SNPWDR_CH1_MASK) >> SNPWDR_CH1_SHIFT;
>
> - put_fifo_with_discard(&lpc_snoop->chan[1], val);
> + put_fifo_with_discard(&lpc_snoop->chan[1], sizeof(val), &val);
> + postval |= (val << 8);
> }
>
> + if (postval)
> + put_fifo_with_discard(&lpc_snoop->combined, sizeof(postval), (u8 *)&postval);
> +
> return IRQ_HANDLED;
> }
>
> @@ -179,6 +192,34 @@ static int aspeed_lpc_snoop_config_irq(struct aspeed_lpc_snoop *lpc_snoop,
> return 0;
> }
>
> +static int aspeed_lpc_create_fifo_chardev(struct aspeed_lpc_snoop_fifo *fifo,
> + struct device *dev, int devnum)
> +{
> + int rc = 0;
> +
> + init_waitqueue_head(&fifo->wq);
> + /* Create FIFO datastructure */
> + rc = kfifo_alloc(&fifo->fifo,
> + SNOOP_FIFO_SIZE, GFP_KERNEL);
> + if (rc)
> + return rc;
> +
> + fifo->miscdev.minor = MISC_DYNAMIC_MINOR;
> + fifo->miscdev.name =
> + devm_kasprintf(dev, GFP_KERNEL, "%s%d", DEVICE_NAME, devnum);
> + fifo->miscdev.fops = &snoop_fops;
> + fifo->miscdev.parent = dev;
> +
> + return misc_register(&fifo->miscdev);
> +}
> +
> +static void aspeed_lpc_destroy_fifo_chardev(struct aspeed_lpc_snoop_fifo *fifo)
> +{
> +
> + kfifo_free(&fifo->fifo);
> + misc_deregister(&fifo->miscdev);
> +}
> +
> static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
> struct device *dev,
> int channel, u16 lpc_port)
> @@ -188,19 +229,8 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
> 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);
> + rc = aspeed_lpc_create_fifo_chardev(&lpc_snoop->chan[channel],
> + dev, channel);
> if (rc)
> return rc;
>
> @@ -250,8 +280,7 @@ static void aspeed_lpc_disable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
> return;
> }
>
> - kfifo_free(&lpc_snoop->chan[channel].fifo);
> - misc_deregister(&lpc_snoop->chan[channel].miscdev);
> + aspeed_lpc_destroy_fifo_chardev(&lpc_snoop->chan[channel]);
> }
>
> static int aspeed_lpc_snoop_probe(struct platform_device *pdev)
> @@ -295,9 +324,18 @@ static int aspeed_lpc_snoop_probe(struct platform_device *pdev)
> 1, &port) == 0) {
> rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 1, port);
> if (rc)
> - aspeed_lpc_disable_snoop(lpc_snoop, 0);
> + goto err_port1;
> +
> + rc = aspeed_lpc_create_fifo_chardev(&lpc_snoop->combined, dev, 2);
> + if (rc)
> + goto err_combined;
> }
>
> + return rc;
> +err_combined:
> + aspeed_lpc_disable_snoop(lpc_snoop, 1);
> +err_port1:
> + aspeed_lpc_disable_snoop(lpc_snoop, 0);
> return rc;
> }
>
> @@ -309,6 +347,9 @@ static int aspeed_lpc_snoop_remove(struct platform_device *pdev)
> aspeed_lpc_disable_snoop(lpc_snoop, 0);
> aspeed_lpc_disable_snoop(lpc_snoop, 1);
>
> + /* disable combined fifo device */
> + aspeed_lpc_destroy_fifo_chardev(&lpc_snoop->combined);
> +
> return 0;
> }
>
> --
> 2.20.1
>
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