Problem reading and programming memory location...

[neorf3k]

Hi Anatolij,
thank you so much for you answer… monday i’ll test… 
i answer you just to complete the information:
we are using an mpc5200b and the details for that reg located at: 0x10020000 are:

Chip select 4 specification:
Lp_cs4
bus size: 8 bit
bus control: 2 wait state R/W ACK disabled
size allocated: 4 KByte

Our Register 8 bit LP_cs4 (we want to write)

cs4 offset: 0x001

Thank you again..

Lorenzo

On 16/nov/2013, at 03:29 PM, Anatolij Gustschin <agust at denx.de> wrote:

> Hi Lorenzo,
> 
> see my comments below.
> 
> On Fri, 15 Nov 2013 17:27:30 +0100
> neorf3k <neorf3k at gmail.com> wrote:
> 
>> Hello again, I’ve tried this code, but we are not able to
>> change cs4 reg value… what could be?
>> 
>> —
>> 
>> #define MALab_DEVICE_NAME	"MALab"
>> #define MPC5xxx_MM_CS4_START	(MBAR_BASE + 0x0024)
>> #define MPC5xxx_MM_CS4_STOP	(MBAR_BASE + 0x0028)
>> #define MPC5xxx_MM_IPBI	 (MBAR_BASE + 0x0054)
>> 
>> #define MALab_MM_START	 0x10020000U
>> #define MALab_MM_END	 0x10020FFFU
> 
> Please change MALab_MM_END to 0x10030000U.
> 
>> #define MALab_MM_SIZE	 0x00001000U
>> 
>> int init_module(void) { ...
>>    u16 cs4_start_value;
>>    u16 cs4_stop_value;
>>    u32 cs4_enable_value;
>> 
>>    u8 rvoice_ioaddr_value;
>> 
>> 
>>    // reserve a page of memory for our hardware /proc/iomem
>>    if ( check_region(MALab_MM_START,MALab_MM_SIZE) ) {
>>        printk (KERN_ALERT "LED init_module: memory already in use\n");
>>        return -EBUSY;
>>    }
>> 
>> 
>>    request_mem_region(MALab_MM_START,MALab_MM_SIZE,MALab_DEVICE_NAME);
>> 
>> 
>>    void __iomem *cs0_reg   = ioremap ((volatile unsigned long)(MBAR_BASE + 0x0300), 4);
>>    void __iomem *cs3_reg   = ioremap ((volatile unsigned long)(MBAR_BASE + 0x030C), 4);
>> 
>>    void __iomem *ipbi_cr = ioremap ((volatile unsigned long)(MPC5xxx_MM_IPBI), 4);
>>    void __iomem *cs4_start  = ioremap ((volatile unsigned long)(MPC5xxx_MM_CS4_START + 2), 2);
>>    void __iomem *cs4_stop   = ioremap ((volatile unsigned long)(MPC5xxx_MM_CS4_STOP + 2), 2);
>> 
>>    void __iomem *cs4_enable   = ioremap ((volatile unsigned long)(MBAR_BASE + 0x0310), 4);
>>    void __iomem *cs_ctrl_reg   = ioremap ((volatile unsigned long)(MBAR_BASE + 0x0318), 4);
> 
> 
> this might work, but this is not how ioremap() supposed to be used.
> The mapping is done in 4k-page granularity, so it would be better
> to just map the internal register range my one ioremap() call, i.e.
> 
>    reg_base = ioremap(MBAR_BASE, 0x400);
> 
> and then to calculate the register offsets, i.e.
> 
>   cs0_reg = reg_base + 0x0300;
>   cs0_reg = reg_base + 0x030C;
>   ...
>   ipbi_cr = reg_base + 0x0054;
>   cs4_start = reg_base + 0x0026;
>   cs4_stop = reg_base + 0x002a;
>   ...
> 
> For FPGA mapping you need a separate ioremap() call of course.
> 
>>    void __iomem *rvoice_ioaddr   = ioremap ((volatile unsigned long)(MALab_MM_START), MALab_MM_SIZE);
>> 
>>    //disable CSO
>> 
>>    out_be32(cs0_reg, 0x0004ed00);
>> 
>> 
>>    //disable CS3
>> 
>>    out_be32(cs3_reg, 0x0002cf00);
>> 
>>    // enable LocalBus chip select CS4
>>    out_be32(ipbi_cr, 0x00290001);
> 
> The comment and the code doesn't match here, the code disables
> CS4 to configure the its range, so the comment is confusing.
> 
>>    cs4_start_value=in_be16(cs4_start);
>>    cs4_start_value=MALab_MM_START >>16;
>>    out_be16(cs4_start, cs4_start_value);
>>    cs4_stop_value=in_be16(cs4_stop);
>>    cs4_stop_value=MALab_MM_END >>16;
>>    out_be16(cs4_stop, cs4_stop_value);
> 
> Here is the problem. The _minimal_ chip select range _must_
> be 64 KiB, otherwise the register access can't work. Your
> current chip select 4 range is less then 1 KiB:
> 
>  0x10020FFF - 0x10020000 = 0xFFF
> 
> Since you right-shift the start and stop values by 16,
> the chip select start and stop registers are both 0x1002.
> The resulting chip select address range is 0. Therefore
> please set MALab_MM_END value to 0x10030000.
> 
> Thanks,
> Anatolij

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