Re: [PATCH v2 1/2] staging: axis-fifo: introduce helper functions for register access

[Greg KH <gregkh@linuxfoundation.org>]

On Wed, Jan 14, 2026 at 10:23:16PM +0900, Minu Jin wrote:
> This patch introduces axis_fifo_read_reg(), axis_fifo_write_reg()
> to wrap raw ioread32, iowrite32 calls. Using these helper functions
> improves code readability and provides a cleaner abstraction for
> hardware register access.
> 
> All existing single register I/O calls updated to use these
> new helpers. This refactoring also ensures a consistent access
> pattern and makes future maintenance easier.
> 
> Signed-off-by: Minu Jin <s9430939@naver.com>
> ---
>  drivers/staging/axis-fifo/axis-fifo.c | 45 ++++++++++++++++-----------
>  1 file changed, 27 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
> index 509d620d6ce7..525156583c4a 100644
> --- a/drivers/staging/axis-fifo/axis-fifo.c
> +++ b/drivers/staging/axis-fifo/axis-fifo.c
> @@ -145,16 +145,26 @@ struct axis_fifo_debug_reg {
>   * ----------------------------
>   */
>  
> +static inline u32 axis_fifo_read_reg(struct axis_fifo *fifo, int offset)
> +{
> +	return ioread32(fifo->base_addr + offset);
> +}
> +
> +static inline void axis_fifo_write_reg(struct axis_fifo *fifo, int offset, u32 val)
> +{
> +	iowrite32(val, fifo->base_addr + offset);
> +}
> +
>  static void reset_ip_core(struct axis_fifo *fifo)
>  {
> -	iowrite32(XLLF_SRR_RESET_MASK, fifo->base_addr + XLLF_SRR_OFFSET);
> -	iowrite32(XLLF_TDFR_RESET_MASK, fifo->base_addr + XLLF_TDFR_OFFSET);
> -	iowrite32(XLLF_RDFR_RESET_MASK, fifo->base_addr + XLLF_RDFR_OFFSET);
> -	iowrite32(XLLF_INT_TC_MASK | XLLF_INT_RC_MASK | XLLF_INT_RPURE_MASK |
> +	axis_fifo_write_reg(fifo, XLLF_SRR_OFFSET, XLLF_SRR_RESET_MASK);
> +	axis_fifo_write_reg(fifo, XLLF_TDFR_OFFSET, XLLF_TDFR_RESET_MASK);
> +	axis_fifo_write_reg(fifo, XLLF_RDFR_OFFSET, XLLF_RDFR_RESET_MASK);
> +	axis_fifo_write_reg(fifo, XLLF_IER_OFFSET, XLLF_INT_TC_MASK |
> +			XLLF_INT_RC_MASK | XLLF_INT_RPURE_MASK |
>  		  XLLF_INT_RPORE_MASK | XLLF_INT_RPUE_MASK |
> -		  XLLF_INT_TPOE_MASK | XLLF_INT_TSE_MASK,
> -		  fifo->base_addr + XLLF_IER_OFFSET);
> -	iowrite32(XLLF_INT_CLEAR_ALL, fifo->base_addr + XLLF_ISR_OFFSET);
> +		  XLLF_INT_TPOE_MASK | XLLF_INT_TSE_MASK);
> +	axis_fifo_write_reg(fifo, XLLF_ISR_OFFSET, XLLF_INT_CLEAR_ALL);
>  }
>  
>  /**
> @@ -192,7 +202,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
>  		if (!mutex_trylock(&fifo->read_lock))
>  			return -EAGAIN;
>  
> -		if (!ioread32(fifo->base_addr + XLLF_RDFO_OFFSET)) {
> +		if (!axis_fifo_read_reg(fifo, XLLF_RDFO_OFFSET)) {
>  			ret = -EAGAIN;
>  			goto end_unlock;
>  		}
> @@ -203,7 +213,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
>  		 */
>  		mutex_lock(&fifo->read_lock);
>  		ret = wait_event_interruptible_timeout(fifo->read_queue,
> -						       ioread32(fifo->base_addr + XLLF_RDFO_OFFSET),
> +						       axis_fifo_read_reg(fifo, XLLF_RDFO_OFFSET),
>  						       read_timeout);
>  
>  		if (ret <= 0) {
> @@ -218,7 +228,7 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf,
>  		}
>  	}
>  
> -	bytes_available = ioread32(fifo->base_addr + XLLF_RLR_OFFSET);
> +	bytes_available = axis_fifo_read_reg(fifo, XLLF_RLR_OFFSET);
>  	words_available = bytes_available / sizeof(u32);
>  	if (!bytes_available) {
>  		dev_err(fifo->dt_device, "received a packet of length 0\n");
> @@ -334,8 +344,7 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
>  		if (!mutex_trylock(&fifo->write_lock))
>  			return -EAGAIN;
>  
> -		if (words_to_write > ioread32(fifo->base_addr +
> -					      XLLF_TDFV_OFFSET)) {
> +		if (words_to_write > axis_fifo_read_reg(fifo, XLLF_TDFV_OFFSET)) {
>  			ret = -EAGAIN;
>  			goto end_unlock;
>  		}
> @@ -347,7 +356,7 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
>  		 */
>  		mutex_lock(&fifo->write_lock);
>  		ret = wait_event_interruptible_timeout(fifo->write_queue,
> -						       ioread32(fifo->base_addr + XLLF_TDFV_OFFSET)
> +						       axis_fifo_read_reg(fifo, XLLF_TDFV_OFFSET)
>  								>= words_to_write,
>  						       write_timeout);
>  
> @@ -373,7 +382,7 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf,
>  		iowrite32(txbuf[i], fifo->base_addr + XLLF_TDFD_OFFSET);
>  
>  	/* write packet size to fifo */
> -	iowrite32(len, fifo->base_addr + XLLF_TLR_OFFSET);
> +	axis_fifo_write_reg(fifo, XLLF_TLR_OFFSET, len);
>  
>  	ret = len;
>  	kvfree(txbuf);
> @@ -388,8 +397,8 @@ static irqreturn_t axis_fifo_irq(int irq, void *dw)
>  	struct axis_fifo *fifo = dw;
>  	u32 isr, ier, intr;
>  
> -	ier = ioread32(fifo->base_addr + XLLF_IER_OFFSET);
> -	isr = ioread32(fifo->base_addr + XLLF_ISR_OFFSET);
> +	ier = axis_fifo_read_reg(fifo, XLLF_IER_OFFSET);
> +	isr = axis_fifo_read_reg(fifo, XLLF_ISR_OFFSET);
>  	intr = ier & isr;
>  
>  	if (intr & XLLF_INT_RC_MASK)
> @@ -414,7 +423,7 @@ static irqreturn_t axis_fifo_irq(int irq, void *dw)
>  		dev_err(fifo->dt_device,
>  			"transmit length mismatch error interrupt\n");
>  
> -	iowrite32(XLLF_INT_CLEAR_ALL, fifo->base_addr + XLLF_ISR_OFFSET);
> +	axis_fifo_write_reg(fifo, XLLF_ISR_OFFSET, XLLF_INT_CLEAR_ALL);
>  
>  	return IRQ_HANDLED;
>  }
> @@ -464,7 +473,7 @@ static int axis_fifo_debugfs_regs_show(struct seq_file *m, void *p)
>  	struct axis_fifo *fifo = m->private;
>  
>  	for (reg = regs; reg->name; ++reg) {
> -		u32 val = ioread32(fifo->base_addr + reg->offset);
> +		u32 val = axis_fifo_read_reg(fifo, reg->offset);
>  
>  		seq_printf(m, "%*s: 0x%08x\n", AXIS_FIFO_DEBUG_REG_NAME_MAX_LEN,
>  			   reg->name, val);
> -- 
> 2.43.0
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
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