[PATCH 3/5] powerpc/mpc5121: shared DIU framebuffer support

Timur Tabi timur.tabi at gmail.com
Fri Apr 30 12:05:26 EST 2010


On Thu, Apr 29, 2010 at 6:49 PM, Anatolij Gustschin <agust at denx.de> wrote:


> +void __init mpc5121_ads_init_early(void)
> +{
> +       mpc512x_init_diu();
> +}
> +
>  define_machine(mpc5121_ads) {
>        .name                   = "MPC5121 ADS",
>        .probe                  = mpc5121_ads_probe,
>        .setup_arch             = mpc5121_ads_setup_arch,
>        .init                   = mpc512x_init,
> +       .init_early             = mpc5121_ads_init_early,

How about just doing this?

.init_early             = mpc512x_init_diu,

> +void __init mpc512x_generic_init_early(void)
> +{
> +       mpc512x_init_diu();
> +}
> +
> +void __init mpc512x_generic_setup_arch(void)
> +{
> +       mpc512x_setup_diu();
> +}
> +
>  define_machine(mpc5121_generic) {
>        .name                   = "MPC5121 generic",
>        .probe                  = mpc5121_generic_probe,
>        .init                   = mpc512x_init,
> +       .init_early             = mpc512x_generic_init_early,
> +       .setup_arch             = mpc512x_generic_setup_arch,

And a similar change here.

>        .init_IRQ               = mpc512x_init_IRQ,
>        .get_irq                = ipic_get_irq,
>        .calibrate_decr         = generic_calibrate_decr,
> diff --git a/arch/powerpc/platforms/512x/mpc512x.h b/arch/powerpc/platforms/512x/mpc512x.h
> index b2daca0..1ab6d11 100644
> --- a/arch/powerpc/platforms/512x/mpc512x.h
> +++ b/arch/powerpc/platforms/512x/mpc512x.h
> @@ -16,4 +16,6 @@ extern void __init mpc512x_init(void);
>  extern int __init mpc5121_clk_init(void);
>  void __init mpc512x_declare_of_platform_devices(void);
>  extern void mpc512x_restart(char *cmd);
> +extern void mpc512x_init_diu(void);
> +extern void mpc512x_setup_diu(void);
>  #endif                         /* __MPC512X_H__ */
> diff --git a/arch/powerpc/platforms/512x/mpc512x_shared.c b/arch/powerpc/platforms/512x/mpc512x_shared.c
> index b7f518a..8e297fa 100644
> --- a/arch/powerpc/platforms/512x/mpc512x_shared.c
> +++ b/arch/powerpc/platforms/512x/mpc512x_shared.c
> @@ -16,7 +16,11 @@
>  #include <linux/io.h>
>  #include <linux/irq.h>
>  #include <linux/of_platform.h>
> +#include <linux/fsl-diu-fb.h>
> +#include <linux/bootmem.h>
> +#include <sysdev/fsl_soc.h>
>
> +#include <asm/cacheflush.h>
>  #include <asm/machdep.h>
>  #include <asm/ipic.h>
>  #include <asm/prom.h>
> @@ -53,6 +57,286 @@ void mpc512x_restart(char *cmd)
>                ;
>  }
>
> +struct fsl_diu_shared_fb {
> +       char            gamma[0x300];   /* 32-bit aligned! */

char or u8?

> +       struct diu_ad   ad0;            /* 32-bit aligned! */
> +       phys_addr_t     fb_phys;
> +       size_t          fb_len;
> +       bool            in_use;
> +};

Where did "bool" come from?  Use "int" instead.

> +unsigned int mpc512x_get_pixel_format(unsigned int bits_per_pixel,
> +                                     int monitor_port)
> +{
> +       unsigned int pix_fmt;
> +
> +       switch (bits_per_pixel) {
> +       case 32:
> +               pix_fmt = 0x88883316;
> +               break;
> +       case 24:
> +               pix_fmt = 0x88082219;
> +               break;
> +       case 16:
> +               pix_fmt = 0x65053118;
> +               break;
> +       default:
> +               pix_fmt = 0x00000400;
> +       }
> +       return pix_fmt;
> +}

This is simpler:

       switch (bits_per_pixel) {
       case 32:
               return 0x88883316;
       case 24:
               return 0x88082219;
       case 16:
               return = 0x65053118;
      }

      return 0x00000400;
}

> +       ccm = of_iomap(np, 0);
> +       if (!ccm) {
> +               pr_err("Can't map clock control module reg.\n");
> +               of_node_put(np);
> +               return;
> +       }
> +       of_node_put(np);

This is simpler:

       ccm = of_iomap(np, 0);
       of_node_put(np);
       if (!ccm) {
               pr_err("Can't map clock control module reg.\n");
               return;
       }


> +       np = of_find_node_by_type(NULL, "cpu");
> +       if (np) {
> +               unsigned int size;
> +               const unsigned int *prop =
> +                       of_get_property(np, "bus-frequency", &size);

Since you don't use 'size', you can skip it:

              const unsigned int *prop =
                      of_get_property(np, "bus-frequency", NULL);

> +       } else {
> +               pr_err("Can't find \"cpu\" node.\n");

'cpu' is simpler than \"cpu\"

> +       /* Calculate the pixel clock with the smallest error */
> +       /* calculate the following in steps to avoid overflow */
> +       pr_debug("DIU pixclock in ps - %d\n", pixclock);
> +       temp = (1000000000 / pixclock) * 1000;

I'm pretty sure the compiler will optimize this to:

    temp = (1000000000000UL / pixclock);

so you may as well do it that way.

> +       pixclock = temp;
> +       pr_debug("DIU pixclock freq - %u\n", pixclock);
> +
> +       temp = (temp * 5) / 100; /* pixclock * 0.05 */

The compiler will optimize this to:

    temp /= 20;

> +       pr_debug("deviation = %d\n", temp);
> +       minpixclock = pixclock - temp;
> +       maxpixclock = pixclock + temp;
> +       pr_debug("DIU minpixclock - %lu\n", minpixclock);
> +       pr_debug("DIU maxpixclock - %lu\n", maxpixclock);
> +       pixval = speed_ccb/pixclock;
> +       pr_debug("DIU pixval = %lu\n", pixval);
> +
> +       err = 100000000;

Why do you assign err to this arbitrary value?

> +       bestval = pixval;
> +       pr_debug("DIU bestval = %lu\n", bestval);
> +
> +       bestfreq = 0;
> +       for (i = -1; i <= 1; i++) {
> +               temp = speed_ccb / (pixval+i);
> +               pr_debug("DIU test pixval i=%d, pixval=%lu, temp freq. = %u\n",
> +                       i, pixval, temp);
> +               if ((temp < minpixclock) || (temp > maxpixclock))
> +                       pr_debug("DIU exceeds monitor range (%lu to %lu)\n",
> +                               minpixclock, maxpixclock);
> +               else if (abs(temp - pixclock) < err) {
> +                       pr_debug("Entered the else if block %d\n", i);
> +                       err = abs(temp - pixclock);
> +                       bestval = pixval + i;
> +                       bestfreq = temp;
> +               }
> +       }
> +
> +       pr_debug("DIU chose = %lx\n", bestval);
> +       pr_debug("DIU error = %ld\n NomPixClk ", err);
> +       pr_debug("DIU: Best Freq = %lx\n", bestfreq);
> +       /* Modify DIU_DIV in CCM SCFR1 */
> +       temp = in_be32(ccm + CCM_SCFR1);

Don't use offsets like + CCM_SCFR1.  Create a structure and use that instead.

> +       pr_debug("DIU: Current value of SCFR1: 0x%08x\n", temp);
> +       temp &= ~DIU_DIV_MASK;
> +       temp |= (bestval & DIU_DIV_MASK);
> +       out_be32(ccm + CCM_SCFR1, temp);
> +       pr_debug("DIU: Modified value of SCFR1: 0x%08x\n", temp);
> +       iounmap(ccm);
> +}
> +
> +ssize_t mpc512x_show_monitor_port(int monitor_port, char *buf)
> +{
> +       return snprintf(buf, PAGE_SIZE, "0 - 5121 LCD\n");

There's no point in using snprintf since you're printing a string
literal.  You can use sprintf.

> +}
> +
> +int mpc512x_set_sysfs_monitor_port(int val)
> +{
> +       return 0;
> +}
> +
> +static struct fsl_diu_shared_fb __attribute__ ((__aligned__(8))) diu_shared_fb;
> +
> +#if defined(CONFIG_FB_FSL_DIU) || \
> +    defined(CONFIG_FB_FSL_DIU_MODULE)
> +static inline void mpc512x_free_bootmem(struct page *page)
> +{
> +       __ClearPageReserved(page);
> +       BUG_ON(PageTail(page));
> +       BUG_ON(atomic_read(&page->_count) > 1);
> +       atomic_set(&page->_count, 1);
> +       __free_page(page);
> +       totalram_pages++;
> +}
> +
> +void mpc512x_release_bootmem(void)
> +{
> +       unsigned long addr = diu_shared_fb.fb_phys & PAGE_MASK;
> +       unsigned long size = diu_shared_fb.fb_len;
> +       unsigned long start, end;
> +
> +       if (diu_shared_fb.in_use) {
> +               start = PFN_UP(addr);
> +               end = PFN_DOWN(addr + size);
> +
> +               for (; start < end; start++)
> +                       mpc512x_free_bootmem(pfn_to_page(start));
> +
> +               diu_shared_fb.in_use = false;
> +       }
> +       diu_ops.release_bootmem = NULL;
> +}
> +#endif

Do you really need to use reserve_bootmem?  Have you tried kmalloc or
alloc_pages_exact()?

> +
> +/*
> + * Check if DIU was pre-initialized. If so, perform steps
> + * needed to continue displaying through the whole boot process.
> + * Move area descriptor and gamma table elsewhere, they are
> + * destroyed by bootmem allocator otherwise. The frame buffer
> + * address range will be reserved in setup_arch() after bootmem
> + * allocator is up.
> + */
> +void __init mpc512x_init_diu(void)
> +{
> +       struct device_node *np;
> +       void __iomem *diu_reg;
> +       phys_addr_t desc;
> +       void __iomem *vaddr;
> +       unsigned long mode, pix_fmt, res, bpp;
> +       unsigned long dst;
> +
> +       np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-diu");
> +       if (!np) {
> +               pr_err("No DIU node\n");
> +               return;
> +       }

Shouldn't you be probing as an OF driver instead of manually searching
for the DIU node?

> +
> +       diu_reg = of_iomap(np, 0);
> +       of_node_put(np);
> +       if (!diu_reg) {
> +               pr_err("Can't map DIU\n");
> +               return;
> +       }
> +
> +       mode = in_be32(diu_reg + 0x1c);
> +       if (mode != 1) {

How can in_be32() return a -1?

-- 
Timur Tabi
Linux kernel developer at Freescale


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