#include <linux/module.h> #include <linux/platform_device.h> #include <linux/interrupt.h> #include <linux/gpio.h> #include <mach/regs-lcd.h> #include <plat/gpio-cfg.h> #define DRIVER_NAME "vis_delta"
Introduction The Samsung S3C2410X is a legendary 16/32-bit RISC microcontroller based on the ARM920T core. Despite its age (released in the early 2000s), it remains a cornerstone for embedded systems education (e.g., the popular QQ2440, Mini2440 boards) and legacy industrial control devices. One of the most challenging aspects of working with this SoC is interfacing non-standard peripherals, particularly those referred to under the codename -vis and its accompanying Delta signal conditioning interface.
Use case: .
MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("vis Delta-Sigma Driver for S3C2410X"); The -vis Delta driver for the S3C2410X represents a classic embedded systems challenge: bridging a high-resolution, low-speed Delta-Sigma peripheral to a resource-constrained ARM9 processor while maintaining real-time video synchronization. While the original driver stacks are brittle and heavily tied to kernel 2.6, the principles of bitstream capture, decimation filtering, and DMA offload remain valid today.
static int __init vis_delta_probe(struct platform_device *pdev) int ret; -vis On S3c2410x Delta Driver -
// Request IRQ (trigger on rising clock edge) ret = request_irq(delta_irq, delta_irq_handler, IRQF_TRIGGER_RISING, "vis_delta", NULL); if (ret) goto err_irq;
static int vis_delta_remove(struct platform_device *pdev) free_irq(delta_irq, NULL); gpio_free(delta_data_pin); return 0; #include <linux/module
static long vis_delta_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) struct vis_delta_device *vis = filp->private_data; switch(cmd) case VIS_SET_BRIGHTNESS: // Map Delta-sigma value to LCD PWM writel(arg, vis->reg_base + S3C2410_LCDCON5); break; case VIS_GET_TOUCH_RAW: copy_to_user((void __user *)arg, vis->delta_sigma_samples, sizeof(vis->delta_sigma_samples)); break;