/* * Frame buffer driver for ADV7393/2 video encoder * * Copyright 2006-2009 Analog Devices Inc. * Licensed under the GPL-2 or late. */ /* * TODO: Remove Globals * TODO: Code Cleanup */ #define pr_fmt(fmt) DRIVER_NAME ": " fmt #include <linux/module.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/tty.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/fb.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/types.h> #include <linux/interrupt.h> #include <linux/sched.h> #include <asm/blackfin.h> #include <asm/irq.h> #include <asm/dma.h> #include <linux/uaccess.h> #include <linux/gpio.h> #include <asm/portmux.h> #include <linux/dma-mapping.h> #include <linux/proc_fs.h> #include <linux/platform_device.h> #include <linux/i2c.h> #include "bfin_adv7393fb.h" static int mode = VMODE; static int mem = VMEM; static int nocursor = 1; static const unsigned short ppi_pins[] = { P_PPI0_CLK, P_PPI0_FS1, P_PPI0_FS2, P_PPI0_D0, P_PPI0_D1, P_PPI0_D2, P_PPI0_D3, P_PPI0_D4, P_PPI0_D5, P_PPI0_D6, P_PPI0_D7, P_PPI0_D8, P_PPI0_D9, P_PPI0_D10, P_PPI0_D11, P_PPI0_D12, P_PPI0_D13, P_PPI0_D14, P_PPI0_D15, 0 }; /* * card parameters */ static struct bfin_adv7393_fb_par { /* structure holding blackfin / adv7393 parameters when screen is blanked */ struct { u8 Mode; /* ntsc/pal/? */ } vga_state; atomic_t ref_count; } bfin_par; /* --------------------------------------------------------------------- */ static struct fb_var_screeninfo bfin_adv7393_fb_defined = { .xres = 720, .yres = 480, .xres_virtual = 720, .yres_virtual = 480, .bits_per_pixel = 16, .activate = FB_ACTIVATE_TEST, .height = -1, .width = -1, .left_margin = 0, .right_margin = 0, .upper_margin = 0, .lower_margin = 0, .vmode = FB_VMODE_INTERLACED, .red = {11, 5, 0}, .green = {5, 6, 0}, .blue = {0, 5, 0}, .transp = {0, 0, 0}, }; static struct fb_fix_screeninfo bfin_adv7393_fb_fix = { .id = "BFIN ADV7393", .smem_len = 720 * 480 * 2, .type = FB_TYPE_PACKED_PIXELS, .visual = FB_VISUAL_TRUECOLOR, .xpanstep = 0, .ypanstep = 0, .line_length = 720 * 2, .accel = FB_ACCEL_NONE }; static struct fb_ops bfin_adv7393_fb_ops = { .owner = THIS_MODULE, .fb_open = bfin_adv7393_fb_open, .fb_release = bfin_adv7393_fb_release, .fb_check_var = bfin_adv7393_fb_check_var, .fb_pan_display = bfin_adv7393_fb_pan_display, .fb_blank = bfin_adv7393_fb_blank, .fb_fillrect = cfb_fillrect, .fb_copyarea = cfb_copyarea, .fb_imageblit = cfb_imageblit, .fb_cursor = bfin_adv7393_fb_cursor, .fb_setcolreg = bfin_adv7393_fb_setcolreg, }; static int dma_desc_list(struct adv7393fb_device *fbdev, u16 arg) { if (arg == BUILD) { /* Build */ fbdev->vb1 = l1_data_sram_zalloc(sizeof(struct dmasg)); if (fbdev->vb1 == NULL) goto error; fbdev->av1 = l1_data_sram_zalloc(sizeof(struct dmasg)); if (fbdev->av1 == NULL) goto error; fbdev->vb2 = l1_data_sram_zalloc(sizeof(struct dmasg)); if (fbdev->vb2 == NULL) goto error; fbdev->av2 = l1_data_sram_zalloc(sizeof(struct dmasg)); if (fbdev->av2 == NULL) goto error; /* Build linked DMA descriptor list */ fbdev->vb1->next_desc_addr = fbdev->av1; fbdev->av1->next_desc_addr = fbdev->vb2; fbdev->vb2->next_desc_addr = fbdev->av2; fbdev->av2->next_desc_addr = fbdev->vb1; /* Save list head */ fbdev->descriptor_list_head = fbdev->av2; /* Vertical Blanking Field 1 */ fbdev->vb1->start_addr = VB_DUMMY_MEMORY_SOURCE; fbdev->vb1->cfg = DMA_CFG_VAL; fbdev->vb1->x_count = fbdev->modes[mode].xres + fbdev->modes[mode].boeft_blank; fbdev->vb1->x_modify = 0; fbdev->vb1->y_count = fbdev->modes[mode].vb1_lines; fbdev->vb1->y_modify = 0; /* Active Video Field 1 */ fbdev->av1->start_addr = (unsigned long)fbdev->fb_mem; fbdev->av1->cfg = DMA_CFG_VAL; fbdev->av1->x_count = fbdev->modes[mode].xres + fbdev->modes[mode].boeft_blank; fbdev->av1->x_modify = fbdev->modes[mode].bpp / 8; fbdev->av1->y_count = fbdev->modes[mode].a_lines; fbdev->av1->y_modify = (fbdev->modes[mode].xres - fbdev->modes[mode].boeft_blank + 1) * (fbdev->modes[mode].bpp / 8); /* Vertical Blanking Field 2 */ fbdev->vb2->start_addr = VB_DUMMY_MEMORY_SOURCE; fbdev->vb2->cfg = DMA_CFG_VAL; fbdev->vb2->x_count = fbdev->modes[mode].xres + fbdev->modes[mode].boeft_blank; fbdev->vb2->x_modify = 0; fbdev->vb2->y_count = fbdev->modes[mode].vb2_lines; fbdev->vb2->y_modify = 0; /* Active Video Field 2 */ fbdev->av2->start_addr = (unsigned long)fbdev->fb_mem + fbdev->line_len; fbdev->av2->cfg = DMA_CFG_VAL; fbdev->av2->x_count = fbdev->modes[mode].xres + fbdev->modes[mode].boeft_blank; fbdev->av2->x_modify = (fbdev->modes[mode].bpp / 8); fbdev->av2->y_count = fbdev->modes[mode].a_lines; fbdev->av2->y_modify = (fbdev->modes[mode].xres - fbdev->modes[mode].boeft_blank + 1) * (fbdev->modes[mode].bpp / 8); return 1; } error: l1_data_sram_free(fbdev->vb1); l1_data_sram_free(fbdev->av1); l1_data_sram_free(fbdev->vb2); l1_data_sram_free(fbdev->av2); return 0; } static int bfin_config_dma(struct adv7393fb_device *fbdev) { BUG_ON(!(fbdev->fb_mem)); set_dma_x_count(CH_PPI, fbdev->descriptor_list_head->x_count); set_dma_x_modify(CH_PPI, fbdev->descriptor_list_head->x_modify); set_dma_y_count(CH_PPI, fbdev->descriptor_list_head->y_count); set_dma_y_modify(CH_PPI, fbdev->descriptor_list_head->y_modify); set_dma_start_addr(CH_PPI, fbdev->descriptor_list_head->start_addr); set_dma_next_desc_addr(CH_PPI, fbdev->descriptor_list_head->next_desc_addr); set_dma_config(CH_PPI, fbdev->descriptor_list_head->cfg); return 1; } static void bfin_disable_dma(void) { bfin_write_DMA0_CONFIG(bfin_read_DMA0_CONFIG() & ~DMAEN); } static void bfin_config_ppi(struct adv7393fb_device *fbdev) { if (ANOMALY_05000183) { bfin_write_TIMER2_CONFIG(WDTH_CAP); bfin_write_TIMER_ENABLE(TIMEN2); } bfin_write_PPI_CONTROL(0x381E); bfin_write_PPI_FRAME(fbdev->modes[mode].tot_lines); bfin_write_PPI_COUNT(fbdev->modes[mode].xres + fbdev->modes[mode].boeft_blank - 1); bfin_write_PPI_DELAY(fbdev->modes[mode].aoeft_blank - 1); } static void bfin_enable_ppi(void) { bfin_write_PPI_CONTROL(bfin_read_PPI_CONTROL() | PORT_EN); } static void bfin_disable_ppi(void) { bfin_write_PPI_CONTROL(bfin_read_PPI_CONTROL() & ~PORT_EN); } static inline int adv7393_write(struct i2c_client *client, u8 reg, u8 value) { return i2c_smbus_write_byte_data(client, reg, value); } static inline int adv7393_read(struct i2c_client *client, u8 reg) { return i2c_smbus_read_byte_data(client, reg); } static int adv7393_write_block(struct i2c_client *client, const u8 *data, unsigned int len) { int ret = -1; u8 reg; while (len >= 2) { reg = *data++; ret = adv7393_write(client, reg, *data++); if (ret < 0) break; len -= 2; } return ret; } static int adv7393_mode(struct i2c_client *client, u16 mode) { switch (mode) { case POWER_ON: /* ADV7393 Sleep mode OFF */ adv7393_write(client, 0x00, 0x1E); break; case POWER_DOWN: /* ADV7393 Sleep mode ON */ adv7393_write(client, 0x00, 0x1F); break; case BLANK_OFF: /* Pixel Data Valid */ adv7393_write(client, 0x82, 0xCB); break; case BLANK_ON: /* Pixel Data Invalid */ adv7393_write(client, 0x82, 0x8B); break; default: return -EINVAL; break; } return 0; } static irqreturn_t ppi_irq_error(int irq, void *dev_id) { struct adv7393fb_device *fbdev = (struct adv7393fb_device *)dev_id; u16 status = bfin_read_PPI_STATUS(); pr_debug("%s: PPI Status = 0x%X\n", __func__, status); if (status) { bfin_disable_dma(); /* TODO: Check Sequence */ bfin_disable_ppi(); bfin_clear_PPI_STATUS(); bfin_config_dma(fbdev); bfin_enable_ppi(); } return IRQ_HANDLED; } static int proc_output(char *buf) { char *p = buf; p += sprintf(p, "Usage:\n" "echo 0x[REG][Value] > adv7393\n" "example: echo 0x1234 >adv7393\n" "writes 0x34 into Register 0x12\n"); return p - buf; } static int adv7393_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { int len; len = proc_output(page); if (len <= off + count) *eof = 1; *start = page + off; len -= off; if (len > count) len = count; if (len < 0) len = 0; return len; } static int adv7393_write_proc(struct file *file, const char __user * buffer, size_t count, void *data) { struct adv7393fb_device *fbdev = data; unsigned int val; int ret; ret = kstrtouint_from_user(buffer, count, 0, &val); if (ret) return -EFAULT; adv7393_write(fbdev->client, val >> 8, val & 0xff); return count; } static int bfin_adv7393_fb_probe(struct i2c_client *client, const struct i2c_device_id *id) { int ret = 0; struct proc_dir_entry *entry; int num_modes = ARRAY_SIZE(known_modes); struct adv7393fb_device *fbdev = NULL; if (mem > 2) { dev_err(&client->dev, "mem out of allowed range [1;2]\n"); return -EINVAL; } if (mode > num_modes) { dev_err(&client->dev, "mode %d: not supported", mode); return -EFAULT; } fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL); if (!fbdev) { dev_err(&client->dev, "failed to allocate device private record"); return -ENOMEM; } i2c_set_clientdata(client, fbdev); fbdev->modes = known_modes; fbdev->client = client; fbdev->fb_len = mem * fbdev->modes[mode].xres * fbdev->modes[mode].xres * (fbdev->modes[mode].bpp / 8); fbdev->line_len = fbdev->modes[mode].xres * (fbdev->modes[mode].bpp / 8); /* Workaround "PPI Does Not Start Properly In Specific Mode" */ if (ANOMALY_05000400) { ret = gpio_request_one(P_IDENT(P_PPI0_FS3), GPIOF_OUT_INIT_LOW, "PPI0_FS3") if (ret) { dev_err(&client->dev, "PPI0_FS3 GPIO request failed\n"); ret = -EBUSY; goto free_fbdev; } } if (peripheral_request_list(ppi_pins, DRIVER_NAME)) { dev_err(&client->dev, "requesting PPI peripheral failed\n"); ret = -EFAULT; goto free_gpio; } fbdev->fb_mem = dma_alloc_coherent(NULL, fbdev->fb_len, &fbdev->dma_handle, GFP_KERNEL); if (NULL == fbdev->fb_mem) { dev_err(&client->dev, "couldn't allocate dma buffer (%d bytes)\n", (u32) fbdev->fb_len); ret = -ENOMEM; goto free_ppi_pins; } fbdev->info.screen_base = (void *)fbdev->fb_mem; bfin_adv7393_fb_fix.smem_start = (int)fbdev->fb_mem; bfin_adv7393_fb_fix.smem_len = fbdev->fb_len; bfin_adv7393_fb_fix.line_length = fbdev->line_len; if (mem > 1) bfin_adv7393_fb_fix.ypanstep = 1; bfin_adv7393_fb_defined.red.length = 5; bfin_adv7393_fb_defined.green.length = 6; bfin_adv7393_fb_defined.blue.length = 5; bfin_adv7393_fb_defined.xres = fbdev->modes[mode].xres; bfin_adv7393_fb_defined.yres = fbdev->modes[mode].yres; bfin_adv7393_fb_defined.xres_virtual = fbdev->modes[mode].xres; bfin_adv7393_fb_defined.yres_virtual = mem * fbdev->modes[mode].yres; bfin_adv7393_fb_defined.bits_per_pixel = fbdev->modes[mode].bpp; fbdev->info.fbops = &bfin_adv7393_fb_ops; fbdev->info.var = bfin_adv7393_fb_defined; fbdev->info.fix = bfin_adv7393_fb_fix; fbdev->info.par = &bfin_par; fbdev->info.flags = FBINFO_DEFAULT; fbdev->info.pseudo_palette = kzalloc(sizeof(u32) * 16, GFP_KERNEL); if (!fbdev->info.pseudo_palette) { dev_err(&client->dev, "failed to allocate pseudo_palette\n"); ret = -ENOMEM; goto free_fb_mem; } if (fb_alloc_cmap(&fbdev->info.cmap, BFIN_LCD_NBR_PALETTE_ENTRIES, 0) < 0) { dev_err(&client->dev, "failed to allocate colormap (%d entries)\n", BFIN_LCD_NBR_PALETTE_ENTRIES); ret = -EFAULT; goto free_palette; } if (request_dma(CH_PPI, "BF5xx_PPI_DMA") < 0) { dev_err(&client->dev, "unable to request PPI DMA\n"); ret = -EFAULT; goto free_cmap; } if (request_irq(IRQ_PPI_ERROR, ppi_irq_error, 0, "PPI ERROR", fbdev) < 0) { dev_err(&client->dev, "unable to request PPI ERROR IRQ\n"); ret = -EFAULT; goto free_ch_ppi; } fbdev->open = 0; ret = adv7393_write_block(client, fbdev->modes[mode].adv7393_i2c_initd, fbdev->modes[mode].adv7393_i2c_initd_len); if (ret) { dev_err(&client->dev, "i2c attach: init error\n"); goto free_irq_ppi; } if (register_framebuffer(&fbdev->info) < 0) { dev_err(&client->dev, "unable to register framebuffer\n"); ret = -EFAULT; goto free_irq_ppi; } dev_info(&client->dev, "fb%d: %s frame buffer device\n", fbdev->info.node, fbdev->info.fix.id); dev_info(&client->dev, "fb memory address : 0x%p\n", fbdev->fb_mem); entry = create_proc_entry("driver/adv7393", 0, NULL); if (!entry) { dev_err(&client->dev, "unable to create /proc entry\n"); ret = -EFAULT; goto free_fb; } entry->read_proc = adv7393_read_proc; entry->write_proc = adv7393_write_proc; entry->data = fbdev; return 0; free_fb: unregister_framebuffer(&fbdev->info); free_irq_ppi: free_irq(IRQ_PPI_ERROR, fbdev); free_ch_ppi: free_dma(CH_PPI); free_cmap: fb_dealloc_cmap(&fbdev->info.cmap); free_palette: kfree(fbdev->info.pseudo_palette); free_fb_mem: dma_free_coherent(NULL, fbdev->fb_len, fbdev->fb_mem, fbdev->dma_handle); free_ppi_pins: peripheral_free_list(ppi_pins); free_gpio: if (ANOMALY_05000400) gpio_free(P_IDENT(P_PPI0_FS3)); free_fbdev: kfree(fbdev); return ret; } static int bfin_adv7393_fb_open(struct fb_info *info, int user) { struct adv7393fb_device *fbdev = to_adv7393fb_device(info); fbdev->info.screen_base = (void *)fbdev->fb_mem; if (!fbdev->info.screen_base) { dev_err(&fbdev->client->dev, "unable to map device\n"); return -ENOMEM; } fbdev->open = 1; dma_desc_list(fbdev, BUILD); adv7393_mode(fbdev->client, BLANK_OFF); bfin_config_ppi(fbdev); bfin_config_dma(fbdev); bfin_enable_ppi(); return 0; } static int bfin_adv7393_fb_release(struct fb_info *info, int user) { struct adv7393fb_device *fbdev = to_adv7393fb_device(info); adv7393_mode(fbdev->client, BLANK_ON); bfin_disable_dma(); bfin_disable_ppi(); dma_desc_list(fbdev, DESTRUCT); fbdev->open = 0; return 0; } static int bfin_adv7393_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info) { switch (var->bits_per_pixel) { case 16:/* DIRECTCOLOUR, 64k */ var->red.offset = info->var.red.offset; var->green.offset = info->var.green.offset; var->blue.offset = info->var.blue.offset; var->red.length = info->var.red.length; var->green.length = info->var.green.length; var->blue.length = info->var.blue.length; var->transp.offset = 0; var->transp.length = 0; var->transp.msb_right = 0; var->red.msb_right = 0; var->green.msb_right = 0; var->blue.msb_right = 0; break; default: pr_debug("%s: depth not supported: %u BPP\n", __func__, var->bits_per_pixel); return -EINVAL; } if (info->var.xres != var->xres || info->var.yres != var->yres || info->var.xres_virtual != var->xres_virtual || info->var.yres_virtual != var->yres_virtual) { pr_debug("%s: Resolution not supported: X%u x Y%u\n", __func__, var->xres, var->yres); return -EINVAL; } /* * Memory limit */ if ((info->fix.line_length * var->yres_virtual) > info->fix.smem_len) { pr_debug("%s: Memory Limit requested yres_virtual = %u\n", __func__, var->yres_virtual); return -ENOMEM; } return 0; } static int bfin_adv7393_fb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info) { int dy; u32 dmaaddr; struct adv7393fb_device *fbdev = to_adv7393fb_device(info); if (!var || !info) return -EINVAL; if (var->xoffset - info->var.xoffset) { /* No support for X panning for now! */ return -EINVAL; } dy = var->yoffset - info->var.yoffset; if (dy) { pr_debug("%s: Panning screen of %d lines\n", __func__, dy); dmaaddr = fbdev->av1->start_addr; dmaaddr += (info->fix.line_length * dy); /* TODO: Wait for current frame to finished */ fbdev->av1->start_addr = (unsigned long)dmaaddr; fbdev->av2->start_addr = (unsigned long)dmaaddr + fbdev->line_len; } return 0; } /* 0 unblank, 1 blank, 2 no vsync, 3 no hsync, 4 off */ static int bfin_adv7393_fb_blank(int blank, struct fb_info *info) { struct adv7393fb_device *fbdev = to_adv7393fb_device(info); switch (blank) { case VESA_NO_BLANKING: /* Turn on panel */ adv7393_mode(fbdev->client, BLANK_OFF); break; case VESA_VSYNC_SUSPEND: case VESA_HSYNC_SUSPEND: case VESA_POWERDOWN: /* Turn off panel */ adv7393_mode(fbdev->client, BLANK_ON); break; default: return -EINVAL; break; } return 0; } int bfin_adv7393_fb_cursor(struct fb_info *info, struct fb_cursor *cursor) { if (nocursor) return 0; else return -EINVAL; /* just to force soft_cursor() call */ } static int bfin_adv7393_fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue, u_int transp, struct fb_info *info) { if (regno >= BFIN_LCD_NBR_PALETTE_ENTRIES) return -EINVAL; if (info->var.grayscale) /* grayscale = 0.30*R + 0.59*G + 0.11*B */ red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8; if (info->fix.visual == FB_VISUAL_TRUECOLOR) { u32 value; /* Place color in the pseudopalette */ if (regno > 16) return -EINVAL; red >>= (16 - info->var.red.length); green >>= (16 - info->var.green.length); blue >>= (16 - info->var.blue.length); value = (red << info->var.red.offset) | (green << info->var.green.offset)| (blue << info->var.blue.offset); value &= 0xFFFF; ((u32 *) (info->pseudo_palette))[regno] = value; } return 0; } static int bfin_adv7393_fb_remove(struct i2c_client *client) { struct adv7393fb_device *fbdev = i2c_get_clientdata(client); adv7393_mode(client, POWER_DOWN); if (fbdev->fb_mem) dma_free_coherent(NULL, fbdev->fb_len, fbdev->fb_mem, fbdev->dma_handle); free_dma(CH_PPI); free_irq(IRQ_PPI_ERROR, fbdev); unregister_framebuffer(&fbdev->info); remove_proc_entry("driver/adv7393", NULL); fb_dealloc_cmap(&fbdev->info.cmap); kfree(fbdev->info.pseudo_palette); if (ANOMALY_05000400) gpio_free(P_IDENT(P_PPI0_FS3)); /* FS3 */ peripheral_free_list(ppi_pins); kfree(fbdev); return 0; } #ifdef CONFIG_PM static int bfin_adv7393_fb_suspend(struct device *dev) { struct adv7393fb_device *fbdev = dev_get_drvdata(dev); if (fbdev->open) { bfin_disable_dma(); bfin_disable_ppi(); dma_desc_list(fbdev, DESTRUCT); } adv7393_mode(fbdev->client, POWER_DOWN); return 0; } static int bfin_adv7393_fb_resume(struct device *dev) { struct adv7393fb_device *fbdev = dev_get_drvdata(dev); adv7393_mode(fbdev->client, POWER_ON); if (fbdev->open) { dma_desc_list(fbdev, BUILD); bfin_config_ppi(fbdev); bfin_config_dma(fbdev); bfin_enable_ppi(); } return 0; } static const struct dev_pm_ops bfin_adv7393_dev_pm_ops = { .suspend = bfin_adv7393_fb_suspend, .resume = bfin_adv7393_fb_resume, }; #endif static const struct i2c_device_id bfin_adv7393_id[] = { {DRIVER_NAME, 0}, {} }; MODULE_DEVICE_TABLE(i2c, bfin_adv7393_id); static struct i2c_driver bfin_adv7393_fb_driver = { .driver = { .name = DRIVER_NAME, #ifdef CONFIG_PM .pm = &bfin_adv7393_dev_pm_ops, #endif }, .probe = bfin_adv7393_fb_probe, .remove = bfin_adv7393_fb_remove, .id_table = bfin_adv7393_id, }; static int __init bfin_adv7393_fb_driver_init(void) { #if defined(CONFIG_I2C_BLACKFIN_TWI) || defined(CONFIG_I2C_BLACKFIN_TWI_MODULE) request_module("i2c-bfin-twi"); #else request_module("i2c-gpio"); #endif return i2c_add_driver(&bfin_adv7393_fb_driver); } module_init(bfin_adv7393_fb_driver_init); static void __exit bfin_adv7393_fb_driver_cleanup(void) { i2c_del_driver(&bfin_adv7393_fb_driver); } module_exit(bfin_adv7393_fb_driver_cleanup); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); MODULE_DESCRIPTION("Frame buffer driver for ADV7393/2 Video Encoder"); module_param(mode, int, 0); MODULE_PARM_DESC(mode, "Video Mode (0=NTSC,1=PAL,2=NTSC 640x480,3=PAL 640x480,4=NTSC YCbCr input,5=PAL YCbCr input)"); module_param(mem, int, 0); MODULE_PARM_DESC(mem, "Size of frame buffer memory 1=Single 2=Double Size (allows y-panning / frame stacking)"); module_param(nocursor, int, 0644); MODULE_PARM_DESC(nocursor, "cursor enable/disable");