[PATCH]NUC900 LCD Controller Driver
Andrew Morton
akpm at linux-foundation.org
Fri Jan 29 19:27:55 EST 2010
On Mon, 11 Jan 2010 17:05:44 +0900
Wang Qiang <rurality.linux at gmail.com> wrote:
> hi, Dear Wan
>
> There is the patch of LCD controller driver for nuc900s.
> The Linux LOGO is just fine and the FB-Test application was ok, too.
>
> best regards
> wangqiang
>
>
> ...
>
> @@ -380,6 +381,48 @@ struct platform_device nuc900_device_kpi = {
> .resource = nuc900_kpi_resource,
> };
>
> +#ifdef CONFIG_FB_NUC900
> +
> +static struct resource nuc900_lcd_resource[] = {
> + [0] = {
> + .start = W90X900_PA_LCD,
> + .end = W90X900_PA_LCD + W90X900_SZ_LCD - 1,
> + .flags = IORESOURCE_MEM,
> + },
> + [1] = {
> + .start = IRQ_LCD,
> + .end = IRQ_LCD,
> + .flags = IORESOURCE_IRQ,
> + }
> +};
> +
> +static u64 nuc900_device_lcd_dmamask = 0xffffffffUL;
I suspect this should have type `dma_addr_t', but `struct device' uses
open-coded u64 too. Odd.
It makes no sense to initialise a u64 with an unsigned long value -
it's wrong on a 32-bit machine.
this:
static u64 nuc900_device_lcd_dmamask = -1;
will work.
> +struct platform_device nuc900_device_lcd = {
> + .name = "nuc900-lcd",
> + .id = -1,
> + .num_resources = ARRAY_SIZE(nuc900_lcd_resource),
> + .resource = nuc900_lcd_resource,
> + .dev = {
> + .dma_mask = &nuc900_device_lcd_dmamask,
> + .coherent_dma_mask = 0xffffffffUL
And this gets initialised to 0x00000000ffffffff also. Using -1 will fix.
> + }
> +};
> +
>
> ...
>
> + */
> +#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/init.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/workqueue.h>
> +#include <linux/wait.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/cpufreq.h>
> +#include <linux/io.h>
> +
> +#ifdef CONFIG_PM
Is this ifdef needed?
> +#include <linux/pm.h>
> +#endif
> +
> +#include <mach/map.h>
> +#include <mach/regs-clock.h>
> +#include <mach/regs-ldm.h>
> +#include <mach/fb.h>
> +#include <mach/clkdev.h>
> +
> +#include "nuc900fb.h"
> +
> +/* Debugging stuff */
> +#ifdef CONFIG_FB_NUC900_DEBUG
> +static int debug = 1;
> +#define dprintk(msg...) { printk(KERN_DEBUG "nuc900 lcd: " msg); }
> +#else
> +static int debug;
> +#define dprintk(msg...)
> +#endif
Would be better to use the standard pr_debug(), rather than inventing
private infrastructure. That way you get to enjoy the facilities which
lib/dynamic_debug.c offers.
> +
> +/*
> + * Initialize the nuc900 video (dual) buffer address
> + */
> +static void nuc900fb_set_lcdaddr(struct fb_info *info)
> +{
> + struct nuc900fb_info *fbi = info->par;
> + void __iomem *regs = fbi->io;
> + unsigned long vbaddr1, vbaddr2;
> + vbaddr1 = info->fix.smem_start;
It's conventional to put a blank line beterrn end-of-locals and start-of-code.
> + vbaddr2 = info->fix.smem_start;
> + vbaddr2 += info->fix.line_length * info->var.yres;
> + /*set frambuffer start phy addr*/
Like this:
/* set frambuffer start phy addr */
> + writel(vbaddr1, regs + REG_LCM_VA_BADDR0);
> + writel(vbaddr2, regs + REG_LCM_VA_BADDR1);
> +
> + writel(fbi->regs.lcd_va_fbctrl, regs + REG_LCM_VA_FBCTRL);
> + writel(fbi->regs.lcd_va_scale, regs + REG_LCM_VA_SCALE);
> +}
> +
> +//static void nuc900fb_clk_select(struct fb_info *info, unsigned long pixclk)
> +//{
> +// struct nuc900fb_info *fbi = info->par;
> +// int div;
> +// if (clk <= 15 * 1000 * 1000) {
> +// div = (15 * 1000 * 1000)/
> +// nuc900_driver_clksrc_div(fbi->dev, "ext", 0x2);
> +// }
> +//
> +//}
Please feed the patch through scrupts/checkpatch.pl.
> +/*
> + * calculate divider for lcd div
> + */
> +static unsigned int nuc900fb_calc_pixclk(struct nuc900fb_info *fbi,
> + unsigned long pixclk)
> +{
> + unsigned long clk = fbi->clk_rate;
> + unsigned long long div;
> +
> + /* pixclk is in picseconds. our clock is in Hz*/
> + /* div = (clk * pixclk)/10^12 */
> + div = (unsigned long long)clk * pixclk;
> + div >>= 12;
> + do_div(div, 625 * 625UL * 625);
> +
> + dprintk("pixclk %ld, divisor is %ld\n", pixclk, (long)div);
Perhaps use %lld and remove the cast.
> + return div;
> +}
> +
> +/*
> + * Check the video params of 'var'.
> + */
> +static int nuc900fb_check_var(struct fb_var_screeninfo *var,
> + struct fb_info *info)
> +{
> + struct nuc900fb_info *fbi = info->par;
> + struct nuc900fb_mach_info *mach_info = fbi->dev->platform_data;
> + struct nuc900fb_display *display = NULL;
> + struct nuc900fb_display *default_display = mach_info->displays +
> + mach_info->default_display;
> + int i;
> +
> + dprintk("check_var(var=%p, info=%p)\n", var, info);
> +
> + /* validate x/y resolution */
> + /* choose default mode if possible */
> + if (var->xres == default_display->xres &&
> + var->yres == default_display->yres &&
> + var->bits_per_pixel == default_display->bpp)
> + display = default_display;
> + else
> + for (i = 0; i < mach_info->num_displays; i++)
> + if (var->xres == mach_info->displays[i].xres &&
> + var->yres == mach_info->displays[i].yres &&
> + var->bits_per_pixel == mach_info->displays[i].bpp) {
> + display = mach_info->displays + i;
> + break;
> + }
> +
> + if (display == NULL) {
> + dprintk("wrong resolution or depth %dx%d at %d bit per pixel\n",
> + var->xres, var->yres, var->bits_per_pixel);
Some of the printks in here really should be printks, not the
compile-time-suppressible dprintk(). Please review them all and
convert the ones which will be useful to end-users into printk().
> + return -EINVAL;
> + }
> +
> + /* it should be the same size as the display */
> + var->xres_virtual = display->xres;
> + var->yres_virtual = display->yres;
> + var->height = display->height;
> + var->width = display->width;
> +
> + /* copy lcd settings */
> + var->pixclock = display->pixclock;
> + var->left_margin = display->left_margin;
> + var->right_margin = display->right_margin;
> + var->upper_margin = display->upper_margin;
> + var->lower_margin = display->lower_margin;
> + var->vsync_len = display->vsync_len;
> + var->hsync_len = display->hsync_len;
> +
> + var->transp.offset = 0;
> + var->transp.length = 0;
> +
> + fbi->regs.lcd_dccs = display->dccs;
> + fbi->regs.lcd_device_ctrl = display->devctl;
> + fbi->regs.lcd_va_fbctrl = display->fbctrl;
> + fbi->regs.lcd_va_scale = display->scale;
> +
> + /* set R/G/B possions */
> + switch (var->bits_per_pixel) {
> + case 1:
> + case 2:
> + case 4:
> + case 8:
The above four lines are unneeded, but it's OK keeping them for
documentation purposes.
> + default:
> + var->red.offset = 0;
> + var->red.length = var->bits_per_pixel;
> + var->green = var->red;
> + var->blue = var->red;
> + break;
> + case 12:
> + var->red.length = 4;
> + var->green.length = 4;
> + var->blue.length = 4;
> + var->red.offset = 8;
> + var->green.offset = 4;
> + var->blue.offset = 0;
> + break;
> + case 16:
> + var->red.length = 5;
> + var->green.length = 6;
> + var->blue.length = 5;
> + var->red.offset = 11;
> + var->green.offset = 5;
> + var->blue.offset = 0;
> + break;
> + case 18:
> + var->red.length = 6;
> + var->green.length = 6;
> + var->blue.length = 6;
> + var->red.offset = 12;
> + var->green.offset = 6;
> + var->blue.offset = 0;
> + break;
> + case 32:
> + var->red.length = 8;
> + var->green.length = 8;
> + var->blue.length = 8;
> + var->red.offset = 16;
> + var->green.offset = 8;
> + var->blue.offset = 0;
> + break;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Calculate lcd register values from var setting & save into hw
> + */
> +static void nuc900fb_calculate_lcd_regs(const struct fb_info *info,
> + struct nuc900fb_hw *regs)
> +{
> + const struct fb_var_screeninfo *var = &info->var;
> + int vtt = var->height + var->upper_margin + var->lower_margin;
> + int htt = var->width + var->left_margin + var->right_margin;
> + int hsync = var->width + var->right_margin;
> + int vsync = var->height + var->lower_margin;
newline here, please.
> + regs->lcd_crtc_size = LCM_CRTC_SIZE_VTTVAL(vtt) |
> + LCM_CRTC_SIZE_HTTVAL(htt);
> + regs->lcd_crtc_dend = LCM_CRTC_DEND_VDENDVAL(var->height) |
> + LCM_CRTC_DEND_HDENDVAL(var->width);
> + regs->lcd_crtc_hr = LCM_CRTC_HR_EVAL(var->width + 5) |
> + LCM_CRTC_HR_SVAL(var->width + 1);
> + regs->lcd_crtc_hsync = LCM_CRTC_HSYNC_EVAL(hsync + var->hsync_len) |
> + LCM_CRTC_HSYNC_SVAL(hsync);
> + regs->lcd_crtc_vr = LCM_CRTC_VR_EVAL(vsync + var->vsync_len) |
> + LCM_CRTC_VR_SVAL(vsync);
> +
> +}
> +
>
> ...
>
> +static int nuc900fb_debug_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + if (len < 1)
> + return -EINVAL;
> +
> + if (strnicmp(buf, "on", 2) == 0 ||
> + strnicmp(buf, "1", 1) == 0) {
> + debug = 1;
> + } else if (strnicmp(buf, "off", 3) == 0 ||
> + strnicmp(buf, "0", 1) == 0) {
> + debug = 0;
> +
> + } else {
> + return -EINVAL;
> + }
> +
> + return len;
> +}
Duplicates the above-mentioned dynamic-debug facility.
> +static DEVICE_ATTR(debug, 0666, nuc900fb_debug_show, nuc900fb_debug_store);
> +
>
> ...
>
> +static int __init nuc900fb_map_video_memory(struct fb_info *info)
> +{
> + struct nuc900fb_info *fbi = info->par;
> + dma_addr_t map_dma;
> + unsigned long map_size = PAGE_ALIGN(info->fix.smem_len);
> +
> + dprintk("nuc900fb_map_video_memory(fbi=%p) map_size %lu\n",
> + fbi, map_size);
> +
> + info->screen_base = dma_alloc_writecombine(fbi->dev, map_size,
> + &map_dma, GFP_KERNEL);
Here, do
if (!info->screen_base)
return -ENOMEM;
and the rest of the function gets neater.
> + if (info->screen_base != NULL) {
> + dprintk("nuc900fb_map_video_memory: clear %p:%08lx\n",
> + info->screen_base, map_size);
> + memset(info->screen_base, 0x00, map_size);
> +
> + info->fix.smem_start = map_dma;
> + dprintk("nuc900fb_map_video_memory: "
> + "dma=%08lx cpu=%p size=%08lx\n",
> + info->fix.smem_start, info->screen_base, map_size);
> + }
> + return (info->screen_base) ? 0 : -ENOMEM;
> +}
> +
>
> ...
>
> +static char driver_name[] = "nuc900fb";
> +
> +static int __init nuc900fb_probe(struct platform_device *pdev)
Should this be __devinit?
> +{
> + struct nuc900fb_info *fbi;
> + struct nuc900fb_display *display;
> + struct fb_info *fbinfo;
> + struct nuc900fb_mach_info *mach_info;
> + struct resource *res;
> + int ret;
> + int irq;
> + int i;
> + int size;
> +
> + dprintk("devinit\n");
> + mach_info = pdev->dev.platform_data;
> + if (mach_info == NULL) {
> + dev_err(&pdev->dev,
> + "no platform data for lcd, cannot attach\n");
> + return -EINVAL;
> + }
> +
> + if (mach_info->default_display > mach_info->num_displays) {
> + dev_err(&pdev->dev,
> + "default display No. is %d but only %d displays \n",
> + mach_info->default_display, mach_info->num_displays);
> + return -EINVAL;
> + }
> +
> +
> + display = mach_info->displays + mach_info->default_display;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "no irq for device\n");
> + return -ENOENT;
> + }
> +
> + fbinfo = framebuffer_alloc(sizeof(struct nuc900fb_info), &pdev->dev);
> + if (!fbinfo)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, fbinfo);
> +
> + fbi = fbinfo->par;
> + fbi->dev = &pdev->dev;
> +
> +#ifdef CONFIG_CPU_NUC950
> + fbi->drv_type = LCDDRV_NUC950;
> +#endif
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
>
> ...
>
> +static void nuc900fb_stop_lcd(struct fb_info *info)
> +{
> + struct nuc900fb_info *fbi = info->par;
> + void __iomem *regs = fbi->io;
> + unsigned long flags;
> +
> + local_irq_save(flags);
> + writel((~LCM_DCCS_DISP_INT_EN) | (~LCM_DCCS_VA_EN) | (~LCM_DCCS_OSD_EN),
> + regs + REG_LCM_DCCS);
> + local_irq_restore(flags);
> +}
The local_irq_save() is a worry. What's it doing here? It does
nothing to prevent an interrupt on another CPU!
> +/*
> + * Cleanup
> + */
> +static int nuc900fb_remove(struct platform_device *pdev)
> +{
> + struct fb_info *fbinfo = platform_get_drvdata(pdev);
> + struct nuc900fb_info *fbi = fbinfo->par;
> + int irq;
> +
> + nuc900fb_stop_lcd(fbinfo);
> + msleep(1);
> +
> + nuc900fb_unmap_video_memory(fbinfo);
> +
> + iounmap(fbi->io);
> +
> + irq = platform_get_irq(pdev, 0);
> + free_irq(irq, fbi);
> +
> + release_resource(fbi->mem);
> + kfree(fbi->mem);
> +
> + platform_set_drvdata(pdev, NULL);
> + framebuffer_release(fbinfo);
> +
> + return 0;
> +}
> +
>
> ...
>
The driver generally looks OK to me. Please cc me on any updates.
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