From 02b2a366a64f22cc367911d479297772d6269200 Mon Sep 17 00:00:00 2001 From: Ovidiu Panait Date: Sat, 27 Dec 2025 23:26:39 +0200 Subject: [PATCH] staging: axis-fifo: Remove redundant comments Drop banner-style section header comments and also remove comments around self-explanatory code to reduce clutter and improve readability. No functional changes. Signed-off-by: Ovidiu Panait Link: https://patch.msgid.link/20251227212640.3321310-8-ovidiu.panait.oss@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/axis-fifo/axis-fifo.c | 105 +++----------------------- 1 file changed, 10 insertions(+), 95 deletions(-) diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c index bce32e9da347..adb2e872e692 100644 --- a/drivers/staging/axis-fifo/axis-fifo.c +++ b/drivers/staging/axis-fifo/axis-fifo.c @@ -9,11 +9,6 @@ * See Xilinx PG080 document for IP details */ -/* ---------------------------- - * includes - * ---------------------------- - */ - #include #include #include @@ -34,22 +29,12 @@ #include #include -/* ---------------------------- - * driver parameters - * ---------------------------- - */ - #define DRIVER_NAME "axis_fifo" #define READ_BUF_SIZE 128U /* read buffer length in words */ #define AXIS_FIFO_DEBUG_REG_NAME_MAX_LEN 4 -/* ---------------------------- - * IP register offsets - * ---------------------------- - */ - #define XLLF_ISR_OFFSET 0x00000000 /* Interrupt Status */ #define XLLF_IER_OFFSET 0x00000004 /* Interrupt Enable */ @@ -66,20 +51,10 @@ #define XLLF_TDR_OFFSET 0x0000002C /* Transmit Destination */ #define XLLF_RDR_OFFSET 0x00000030 /* Receive Destination */ -/* ---------------------------- - * reset register masks - * ---------------------------- - */ - #define XLLF_RDFR_RESET_MASK 0x000000a5 /* receive reset value */ #define XLLF_TDFR_RESET_MASK 0x000000a5 /* Transmit reset value */ #define XLLF_SRR_RESET_MASK 0x000000a5 /* Local Link reset value */ -/* ---------------------------- - * interrupt masks - * ---------------------------- - */ - #define XLLF_INT_RPURE_MASK 0x80000000 /* Receive under-read */ #define XLLF_INT_RPORE_MASK 0x40000000 /* Receive over-read */ #define XLLF_INT_RPUE_MASK 0x20000000 /* Receive underrun (empty) */ @@ -92,26 +67,21 @@ static DEFINE_IDA(axis_fifo_ida); -/* ---------------------------- - * types - * ---------------------------- - */ - struct axis_fifo { int id; - void __iomem *base_addr; /* kernel space memory */ + void __iomem *base_addr; - unsigned int rx_fifo_depth; /* max words in the receive fifo */ - unsigned int tx_fifo_depth; /* max words in the transmit fifo */ - int has_rx_fifo; /* whether the IP has the rx fifo enabled */ - int has_tx_fifo; /* whether the IP has the tx fifo enabled */ + unsigned int rx_fifo_depth; + unsigned int tx_fifo_depth; + int has_rx_fifo; + int has_tx_fifo; - wait_queue_head_t read_queue; /* wait queue for asynchronos read */ + wait_queue_head_t read_queue; struct mutex read_lock; /* lock for reading */ - wait_queue_head_t write_queue; /* wait queue for asynchronos write */ + wait_queue_head_t write_queue; struct mutex write_lock; /* lock for writing */ - struct device *dt_device; /* device created from the device tree */ + struct device *dt_device; struct miscdevice miscdev; struct dentry *debugfs_dir; @@ -122,11 +92,6 @@ struct axis_fifo_debug_reg { unsigned int offset; }; -/* ---------------------------- - * implementation - * ---------------------------- - */ - static void reset_ip_core(struct axis_fifo *fifo) { iowrite32(XLLF_SRR_RESET_MASK, fifo->base_addr + XLLF_SRR_OFFSET); @@ -167,10 +132,6 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf, u32 tmp_buf[READ_BUF_SIZE]; if (f->f_flags & O_NONBLOCK) { - /* - * Device opened in non-blocking mode. Try to lock it and then - * check if any packet is available. - */ if (!mutex_trylock(&fifo->read_lock)) return -EAGAIN; @@ -179,10 +140,6 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf, goto end_unlock; } } else { - /* opened in blocking mode - * wait for a packet available interrupt (or timeout) - * if nothing is currently available - */ mutex_lock(&fifo->read_lock); ret = wait_event_interruptible(fifo->read_queue, @@ -208,9 +165,6 @@ static ssize_t axis_fifo_read(struct file *f, char __user *buf, goto err_flush_rx; } - /* read data into an intermediate buffer, copying the contents - * to userspace when the buffer is full - */ copied = 0; while (words_available > 0) { copy = min(words_available, READ_BUF_SIZE); @@ -282,10 +236,6 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf, return -EINVAL; if (f->f_flags & O_NONBLOCK) { - /* - * Device opened in non-blocking mode. Try to lock it and then - * check if there is any room to write the given buffer. - */ if (!mutex_trylock(&fifo->write_lock)) return -EAGAIN; @@ -295,11 +245,6 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf, goto end_unlock; } } else { - /* opened in blocking mode */ - - /* wait for an interrupt (or timeout) if there isn't - * currently enough room in the fifo - */ mutex_lock(&fifo->write_lock); ret = wait_event_interruptible(fifo->write_queue, @@ -317,7 +262,6 @@ static ssize_t axis_fifo_write(struct file *f, const char __user *buf, for (int i = 0; i < words_to_write; ++i) iowrite32(txbuf[i], fifo->base_addr + XLLF_TDFD_OFFSET); - /* write packet size to fifo */ iowrite32(len, fifo->base_addr + XLLF_TLR_OFFSET); ret = len; @@ -508,18 +452,12 @@ end: static int axis_fifo_probe(struct platform_device *pdev) { - struct resource *r_mem; /* IO mem resources */ - struct device *dev = &pdev->dev; /* OS device (from device tree) */ + struct resource *r_mem; + struct device *dev = &pdev->dev; struct axis_fifo *fifo = NULL; int rc = 0; /* error return value */ int irq; - /* ---------------------------- - * init wrapper device - * ---------------------------- - */ - - /* allocate device wrapper memory */ fifo = devm_kzalloc(dev, sizeof(*fifo), GFP_KERNEL); if (!fifo) return -ENOMEM; @@ -533,38 +471,20 @@ static int axis_fifo_probe(struct platform_device *pdev) mutex_init(&fifo->read_lock); mutex_init(&fifo->write_lock); - /* ---------------------------- - * init device memory space - * ---------------------------- - */ - - /* get iospace for the device and request physical memory */ fifo->base_addr = devm_platform_get_and_ioremap_resource(pdev, 0, &r_mem); if (IS_ERR(fifo->base_addr)) return PTR_ERR(fifo->base_addr); - /* ---------------------------- - * init IP - * ---------------------------- - */ - rc = axis_fifo_parse_dt(fifo); if (rc) return rc; reset_ip_core(fifo); - /* ---------------------------- - * init device interrupts - * ---------------------------- - */ - - /* get IRQ resource */ irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; - /* request IRQ */ rc = devm_request_irq(fifo->dt_device, irq, &axis_fifo_irq, 0, DRIVER_NAME, fifo); if (rc) { @@ -573,15 +493,10 @@ static int axis_fifo_probe(struct platform_device *pdev) return rc; } - /* ---------------------------- - * init char device - * ---------------------------- - */ fifo->id = ida_alloc(&axis_fifo_ida, GFP_KERNEL); if (fifo->id < 0) return fifo->id; - /* create character device */ fifo->miscdev.fops = &fops; fifo->miscdev.minor = MISC_DYNAMIC_MINOR; fifo->miscdev.parent = dev; -- 2.47.3