[U-Boot] [PATCH v3 7/8] imx6: SPL support for iMX6 SabreSD

John Tobias john.tobias.ph at gmail.com
Tue Nov 11 18:15:36 CET 2014


On Tue, Nov 11, 2014 at 12:44 AM, Stefano Babic <sbabic at denx.de> wrote:
> Hi John,
>
> On 10/11/2014 01:23, John Tobias wrote:
>> Hi Stefano,
>>
>>
>> On Sun, Nov 9, 2014 at 1:16 PM, Stefano Babic <sbabic at denx.de> wrote:
>>> Hi John,
>>>
>>> On 08/11/2014 22:27, John Tobias wrote:
>>>> This patch will enable the support for SPL on iMX6 SabreSD.
>>>> It tested on SD2 and SD3 mmc port.
>>>> ---
>>>>  board/freescale/mx6sabresd/mx6sabresd.c | 211 +++++++++++++++++++++++++++++++-
>>>>  1 file changed, 209 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/board/freescale/mx6sabresd/mx6sabresd.c b/board/freescale/mx6sabresd/mx6sabresd.c
>>>> index 3d81fff..f443337 100644
>>>> --- a/board/freescale/mx6sabresd/mx6sabresd.c
>>>> +++ b/board/freescale/mx6sabresd/mx6sabresd.c
>>>> @@ -55,8 +55,7 @@ DECLARE_GLOBAL_DATA_PTR;
>>>>
>>>>  int dram_init(void)
>>>>  {
>>>> -     gd->ram_size = get_ram_size((void *)PHYS_SDRAM, PHYS_SDRAM_SIZE);
>>>> -
>>>> +     gd->ram_size = imx_ddr_size();
>>>>       return 0;
>>>>  }
>>>>
>>>> @@ -607,3 +606,211 @@ int checkboard(void)
>>>>       puts("Board: MX6-SabreSD\n");
>>>>       return 0;
>>>>  }
>>>> +
>>>> +#ifdef CONFIG_SPL_BUILD
>>>> +#include <spl.h>
>>>> +#include <libfdt.h>
>>>> +
>>>> +#define BOOT_CFG     0x20D8004
>>>> +#define __REG(x)        (*((volatile u32 *)(x)))
>>>> +
>>>> +struct fsl_esdhc_cfg spl_usdhc_cfg;
>>>> +/*
>>>> + * Got it from mx6q_4x_mt41j128.cfg file
>>>> + */
>>>> +void set_mt41j128_ddr(void)
>>>> +{
>>>> +     __REG(0x020e05a8) = 0x00000028;
>>>> +     __REG(0x020e05b0) = 0x00000028;
>>>> +     __REG(0x020e0524) = 0x00000028;
>>>> +     __REG(0x020e051c) = 0x00000028;
>>>> +
>>>> +     __REG(0x020e0518) = 0x00000028;
>>>> +     __REG(0x020e050c) = 0x00000028;
>>>> +     __REG(0x020e05b8) = 0x00000028;
>>>> +     __REG(0x020e05c0) = 0x00000028;
>>>> +
>>>> +     __REG(0x020e05ac) = 0x00000028;
>>>> +     __REG(0x020e05b4) = 0x00000028;
>>>> +     __REG(0x020e0528) = 0x00000028;
>>>> +     __REG(0x020e0520) = 0x00000028;
>>>> +
>>>> +     __REG(0x020e0514) = 0x00000028;
>>>> +     __REG(0x020e0510) = 0x00000028;
>>>> +     __REG(0x020e05bc) = 0x00000028;
>>>> +     __REG(0x020e05c4) = 0x00000028;
>>>> +
>>>> +     __REG(0x020e056c) = 0x00000030;
>>>> +     __REG(0x020e0578) = 0x00000030;
>>>> +     __REG(0x020e0588) = 0x00000030;
>>>> +     __REG(0x020e0594) = 0x00000030;
>>>> +
>>>> +     __REG(0x020e057c) = 0x00000030;
>>>> +     __REG(0x020e0590) = 0x00000030;
>>>> +     __REG(0x020e0598) = 0x00000030;
>>>> +     __REG(0x020e058c) = 0x00000000;
>>>> +
>>>> +     __REG(0x020e059c) = 0x00003030;
>>>> +     __REG(0x020e05a0) = 0x00003030;
>>>> +     __REG(0x020e0784) = 0x00000028;
>>>> +     __REG(0x020e0788) = 0x00000028;
>>>> +
>>>> +     __REG(0x020e0794) = 0x00000028;
>>>> +     __REG(0x020e079c) = 0x00000028;
>>>> +     __REG(0x020e07a0) = 0x00000028;
>>>> +     __REG(0x020e07a4) = 0x00000028;
>>>> +
>>>> +     __REG(0x020e07a8) = 0x00000028;
>>>> +     __REG(0x020e0748) = 0x00000028;
>>>> +     __REG(0x020e074c) = 0x00000030;
>>>> +     __REG(0x020e0750) = 0x00020000;
>>>> +
>>>> +     __REG(0x020e0758) = 0x00000000;
>>>> +     __REG(0x020e0774) = 0x00020000;
>>>> +     __REG(0x020e078c) = 0x00000030;
>>>> +     __REG(0x020e0798) = 0x000C0000;
>>>> +
>>>> +     __REG(0x021b081c) = 0x33333333;
>>>> +     __REG(0x021b0820) = 0x33333333;
>>>> +     __REG(0x021b0824) = 0x33333333;
>>>> +     __REG(0x021b0828) = 0x33333333;
>>>> +
>>>> +     __REG(0x021b481c) = 0x33333333;
>>>> +     __REG(0x021b4820) = 0x33333333;
>>>> +     __REG(0x021b4824) = 0x33333333;
>>>> +     __REG(0x021b4828) = 0x33333333;
>>>> +
>>>> +     __REG(0x021b0018) = 0x00001740;
>>>> +
>>>> +     __REG(0x021b001c) = 0x00008000;
>>>> +     __REG(0x021b000c) = 0x8A8F7975;
>>>> +     __REG(0x021b0010) = 0xFF538E64;
>>>> +     __REG(0x021b0014) = 0x01FF00DB;
>>>> +     __REG(0x021b002c) = 0x000026D2;
>>>> +
>>>> +     __REG(0x021b0030) = 0x008F0E21;
>>>> +     __REG(0x021b0008) = 0x09444040;
>>>> +     __REG(0x021b0004) = 0x00020036;
>>>> +     __REG(0x021b0040) = 0x00000047;
>>>> +     __REG(0x021b0000) = 0x841A0000;
>>>> +
>>>> +     __REG(0x021b001c) = 0x04088032;
>>>> +     __REG(0x021b001c) = 0x00008033;
>>>> +     __REG(0x021b001c) = 0x00428031;
>>>> +     __REG(0x021b001c) = 0x09408030;
>>>> +
>>>> +     __REG(0x021b001c) = 0x04008040;
>>>> +     __REG(0x021b0800) = 0xA1380003;
>>>> +     __REG(0x021b0020) = 0x00005800;
>>>> +     __REG(0x021b0818) = 0x00000007;
>>>> +     __REG(0x021b4818) = 0x00000007;
>>>> +
>>>> +     /* Calibration values based on ARD and 528MHz */
>>>> +     __REG(0x021b083c) = 0x434B0358;
>>>> +     __REG(0x021b0840) = 0x033D033C;
>>>> +     __REG(0x021b483c) = 0x03520362;
>>>> +     __REG(0x021b4840) = 0x03480318;
>>>> +     __REG(0x021b0848) = 0x41383A3C;
>>>> +     __REG(0x021b4848) = 0x3F3C374A;
>>>> +     __REG(0x021b0850) = 0x42434444;
>>>> +     __REG(0x021b4850) = 0x4932473A;
>>>> +
>>>> +     __REG(0x021b080c) = 0x001F001F;
>>>> +     __REG(0x021b0810) = 0x001F001F;
>>>> +
>>>> +     __REG(0x021b480c) = 0x001F001F;
>>>> +     __REG(0x021b4810) = 0x001F001F;
>>>> +
>>>> +     __REG(0x021b08b8) = 0x00000800;
>>>> +     __REG(0x021b48b8) = 0x00000800;
>>>> +
>>>> +     __REG(0x021b0404) = 0x00011006;
>>>> +     __REG(0x021b0004) = 0x00025576;
>>>> +
>>>> +     __REG(0x021b001c) = 0x00000000;
>>>> +
>>>> +     __REG(0x020c4068) = 0x00C03F3F;
>>>> +     __REG(0x020c406c) = 0x0030FC00;
>>>> +     __REG(0x020c4070) = 0x0FFFC000;
>>>> +     __REG(0x020c4074) = 0x3FF00000;
>>>> +     __REG(0x020c4078) = 0x00FFF300;
>>>> +     __REG(0x020c407c) = 0x0F0000C3;
>>>> +     __REG(0x020c4080) = 0x000003FF;
>>>> +}
>>>> +
>>>
>>> This cannot be accepted. Firstly, you cannot use fixed offset. The code
>>> you propose here is very difficult to maintain.
>>>
>>> Then, please take a look at the i.MX6 boards that are already supporting
>>> SPL (ventana and novena). There is a logical separation between iomux,
>>> calibration, and so on. You have to provide tables, and you should then
>>> call the common functions:
>>>
>>>         mx6dq_dram_iocfg();
>>>         mx6_dram_cfg();
>>
>> The reason why I did not use the two functions you've mentioned is that the
>> contents of mx6q_4x_mt41j128.cfg are very difficult to convert according to the
>> data structures being required by the two functions above.
>
> Yes, but these functions are the result of a very long discussion on the
> ML about how it is possible to support several flavours of the SOC
> (MX6Q, MX6DL), having one single binary for all of them.
>
>>
>> It's barely plain text and it requires a lot of time to look for the
>> register address
>> name it the datasheet.
>
> This is also a reason to get rid of them. DCD tables are more difficult
> to maintain. However, the .cfg file can be parsed by the compiler. The
> sabresd was added to mainline before the patch for gcc was added. See
> other i.MX6 boards, for example nitrogen6x.
>>
>>>
>>> Again, please take a look at the boards I mentioned.
>>>
>>>> +/*
>>>> + * This section require the differentiation
>>>> + * between iMX6 Sabre Families.
>>>> + * But for now, it will configure only for
>>>> + * SabreSD.
>>>> + */
>>>> +static void spl_dram_init(void)
>>>> +{
>>>> +     set_mt41j128_ddr();
>>>> +}
>>>> +
>>>> +int spl_board_mmc_init(bd_t *bis)
>>>> +{
>>>> +     unsigned reg = readl(BOOT_CFG);
>>>> +     /*
>>>> +      * Upon reading BOOT_CFG register the following map is done:
>>>> +      * (U-boot device node)    (Physical Port)
>>>> +      * 0x840                   SD2
>>>> +      * 0x1040                  SD3
>>>> +      * 0x1840                  eMMC
>>>> +      */
>>>
>>> You add a new entry point here (spl_board_mmc_init), but why cannot you
>>> do this in the functions already supplied by SPL ? Why not in board_init_f ?
>>
>> When the spl_mmc_load_image function being called, it call
>> mmc_initialize. By default, the mmc_initialize
>> call board_mmc_init. By looking the said function, it initialize all mmc ports.
>>
>> While, in spl_board_mmc_init, only initialize the current mmc port.
>
> ok - but which is the issue by initializing all ports ? I mean, if
> board_mmc_init initialize all ports including what you need in SPL,
> which is the reason to exclude the other ones ?
>

When board_mmc_init initialize all ports, we can issue a command
at uboot console to switch to different port.
e.g:

mmc dev 0 (e.g. SD4)
mmc dev 1  (e.g. SD2)
mmc dev 2 (e.g. SD3)

We can also re-map which is index 0, 1 and 2 by re-arranging the contents of

struct fsl_esdhc_cfg usdhc_cfg[3] = {
    {USDHC4_BASE_ADDR},
    {USDHC2_BASE_ADDR},
    {USDHC3_BASE_ADDR},
};

Assuming the bootstrap is configured to port 3 (USDHC3). The SPL image will
call spl_mmc_load_image to load the uboot image. In order to do that,
it will call
the find_mmc_device(0), based on example above the index 0 is port 4, index 1
is port 2 and index 2 is port 3. The find_mmc_device will return with errors
because it couldn't initialize the said port.

So by default, the user should switch back the bootstrap to port 4 in
order to load the
uboot correctly. Then, if the user really want to use the different
ports, they have
to change the arrangement of the contents of usdhc_cfg and compile the
u-boot again.

In spl_board_mmc_init function, it will read the bootstrap and configure it. The
settings are passed to fsl_esdhc_initialize which is to be stored in
index 0. So,
find_mmc_device(0) could get a correct information.

Then, switching to different bootstrap doesn't require to re-compile the image.

>>
>>>
>>>> +     switch (reg) {
>>>> +     case 0x840:
>>>> +             imx_iomux_v3_setup_multiple_pads(
>>>> +                     usdhc2_pads, ARRAY_SIZE(usdhc2_pads));
>>>> +             spl_usdhc_cfg.esdhc_base = USDHC2_BASE_ADDR;
>>>> +             spl_usdhc_cfg.sdhc_clk = mxc_get_clock(MXC_ESDHC2_CLK);
>>>> +             gd->arch.sdhc_clk = spl_usdhc_cfg.sdhc_clk;
>>>> +             break;
>>>> +     case 0x1040:
>>>> +             imx_iomux_v3_setup_multiple_pads(
>>>> +                     usdhc3_pads, ARRAY_SIZE(usdhc3_pads));
>>>> +             spl_usdhc_cfg.esdhc_base = USDHC3_BASE_ADDR;
>>>> +             spl_usdhc_cfg.sdhc_clk = mxc_get_clock(MXC_ESDHC3_CLK);
>>>> +             gd->arch.sdhc_clk = spl_usdhc_cfg.sdhc_clk;
>>>> +             break;
>>>> +     case 0x1840:
>>>> +             imx_iomux_v3_setup_multiple_pads(
>>>> +                     usdhc4_pads, ARRAY_SIZE(usdhc4_pads));
>>>> +             spl_usdhc_cfg.esdhc_base = USDHC4_BASE_ADDR;
>>>> +             spl_usdhc_cfg.sdhc_clk = mxc_get_clock(MXC_ESDHC4_CLK);
>>>> +             gd->arch.sdhc_clk = spl_usdhc_cfg.sdhc_clk;
>>>> +             break;
>>>> +     }
>>>> +
>>>> +     return fsl_esdhc_initialize(bis, &spl_usdhc_cfg);
>>>> +}
>>>> +
>>>> +void board_init_f(ulong dummy)
>>>> +{
>>>> +     /* setup AIPS and disable watchdog */
>>>> +     arch_cpu_init();
>>>> +
>>>> +     /* iomux and setup of i2c */
>>>> +     board_early_init_f();
>>>
>>> ??
>>>
>>> A "early" function is generally called by common code at a different
>>> point. It makes no sense to call it inside board_init_f()
>>>
>>>> +
>>>> +     /* setup GP timer */
>>>> +     timer_init();
>>>> +
>>>
>>> Then I am expecting iomux setuup---
>>
>> The iomux setup being called in board_early_init_f...
>>
>>>
>>>> +     /* UART clocks enabled and gd valid - init serial console */
>>>> +     preloader_console_init();
>>>> +
>>>> +     /* DDR initialization */
>>>> +     spl_dram_init();
>>>
>>> and here calling the already supplied functions.
>>>
>>>> +
>>>> +     /* Clear the BSS. */
>>>> +     memset(__bss_start, 0, __bss_end - __bss_start);
>>>> +
>>>> +     /* load/boot image from boot device */
>>>> +     board_init_r(NULL, 0);
>>>> +}
>>>> +
>>>> +void reset_cpu(ulong addr)
>>>> +{
>>>> +}
>>>> +#endif
>>>>
>>>
>
> Best regards,
> Stefano Babic
>
>
> --
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> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
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