On 05/29/2012 12:29 PM, Prafulla Wadaskar wrote:
>> -----Original Message-----
>> From: Valentin Longchamp [mailto:valentin.longch...@keymile.com]
>> Sent: 29 May 2012 14:02
>> To: Prafulla Wadaskar
>> Cc: holger.bru...@keymile.com; u-boot@lists.denx.de
>> Subject: Re: [PATCH 2/3] spi/kirkwood: support spi_claim/release_bus
>> functions
>>
>> On 05/24/2012 10:35 AM, Prafulla Wadaskar wrote:
>>>> -----Original Message-----
>>>> From: Valentin Longchamp [mailto:valentin.longch...@keymile.com]
>>>> Sent: 16 May 2012 16:24
>>>> To: Prafulla Wadaskar; holger.bru...@keymile.com
>>>> Cc: Valentin Longchamp; u-boot@lists.denx.de; Holger Brunck;
>> Prafulla
>>>> Wadaskar
>>>> Subject: [PATCH 2/3] spi/kirkwood: support spi_claim/release_bus
>>>> functions
>>>>
>>>> These two function nows ensure that the MPP is configured correctly
>>>> for
>>>> the SPI controller before any SPI access, and restore the initial
>>>> configuration when the access is over.
>>>>
>>>> Since the used pins for the SPI controller can differ (2
>> possibilities
>>>> for each signal), the used pins are configured with
>>>> CONFIG_SYS_KW_SPI_MPP.
>>>>
>>>> Signed-off-by: Valentin Longchamp <valentin.longch...@keymile.com>
>>>> cc: Holger Brunck <holger.bru...@keymile.com>
>>>> cc: Prafulla Wadaskar <prafu...@marvell.com>
>>>> ---
>>>> arch/arm/include/asm/arch-kirkwood/spi.h | 9 ++++++++
>>>> drivers/spi/kirkwood_spi.c | 34
>>>> ++++++++++++++++++++++++++++++
>>>> 2 files changed, 43 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/arch/arm/include/asm/arch-kirkwood/spi.h
>>>> b/arch/arm/include/asm/arch-kirkwood/spi.h
>>>> index 1d5043f..305c573 100644
>>>> --- a/arch/arm/include/asm/arch-kirkwood/spi.h
>>>> +++ b/arch/arm/include/asm/arch-kirkwood/spi.h
>>>> @@ -37,6 +37,15 @@ struct kwspi_registers {
>>>> u32 irq_mask; /* 0x10614 */
>>>> };
>>>>
>>>> +#define CSn_MPP7 0x1
>>>> +#define MOSI_MPP6 0x2
>>>> +#define SCK_MPP10 0x4
>>>> +#define MISO_MPP11 0x8
>>>
>>> Let's define above as (1 << x) to make it more readable.
>>
>> OK
>>
>>>
>>>> +
>>>> +#ifndef CONFIG_SYS_KW_SPI_MPP
>>>> +#define CONFIG_SYS_KW_SPI_MPP 0x0
>>>
>>> Some more documentation is needed, you need to explain how each bit
>> we are using to configure the SPI-MPPs
>>
>> Not sure I understand what you mean here. But I think that you mean
>> that I would
>> have to document that bit 1 is for CSn signal (MPP0 or MPP7), bit 2
>> for MOSI
>> signal (MPP1 or MPP6) and so on ... OK will do it.
>
> Exactly,
>
>>
>> Would you want me to define CSn_MPP0 as 0x0 (or (0 << 0) ) and
>> MOSI_MPP1 as 0x0
>> and so on as well ?
>
> Use any four bits for four configuration, I would suggest to use bit0 to
> bit-3.
That's already how it is implemented ...:
bit 0: selects pin for CSn (MPP0 if 0, MPP7 if 1)
bit 1: selects pin for MOSI (MPP1 if 0, MPP6 if 1)
bit 2: selects pin for SCK (MPP2 if 0, MPP10 if 1)
bit 3: selects pin for MISO (MPP3 if 0, MPP11 if 1)
>
> Regards..
> Prafulla . . .
>
>>
>>>
>>>> +#endif
>>>> +
>>>> #define KWSPI_CLKPRESCL_MASK 0x1f
>>>> #define KWSPI_CSN_ACT 1 /* Activates serial memory interface
>>>> */
>>>> #define KWSPI_SMEMRDY (1 << 1) /* SerMem Data xfer ready */
>>>> diff --git a/drivers/spi/kirkwood_spi.c
>> b/drivers/spi/kirkwood_spi.c
>>>> index db8ba8b..0877915 100644
>>>> --- a/drivers/spi/kirkwood_spi.c
>>>> +++ b/drivers/spi/kirkwood_spi.c
>>>> @@ -88,11 +88,45 @@ void spi_free_slave(struct spi_slave *slave)
>>>>
>>>> int spi_claim_bus(struct spi_slave *slave)
>>>> {
>>>
>>> Instead define here
>>> #ifdef CONFIG_SYS_KW_SPI_MPP, otherwise build with default.
>>
>> OK, if you prefer it this way, it is fine for me. This implies that I
>> have to
>> remove the above #ifndef CONFIG_SYS_KW_SPI_MPP and that the boards
>> that want to
>> use this will have to #define CONFIG_SYS_KW_SPI_MPP in their config.
>>
>>>
>>>> + u32 config;
>>>> + u32 spi_mpp_config[5];
>>>> +
>>>> + config = CONFIG_SYS_KW_SPI_MPP;
>>>> +
>>>> + if (config & CSn_MPP7)
>>>> + spi_mpp_config[0] = MPP7_SPI_SCn;
>>>> + else
>>>> + spi_mpp_config[0] = MPP0_SPI_SCn;
>>>> +
>>>> + if (config & MOSI_MPP6)
>>>> + spi_mpp_config[1] = MPP6_SPI_MOSI;
>>>> + else
>>>> + spi_mpp_config[1] = MPP1_SPI_MOSI;
>>>> +
>>>> + if (config & SCK_MPP10)
>>>> + spi_mpp_config[2] = MPP10_SPI_SCK;
>>>> + else
>>>> + spi_mpp_config[2] = MPP2_SPI_SCK;
>>>> +
>>>> + if (config & MISO_MPP11)
>>>> + spi_mpp_config[3] = MPP11_SPI_MISO;
>>>> + else
>>>> + spi_mpp_config[3] = MPP3_SPI_MISO;
>>>> +
>>>> + spi_mpp_config[4] = 0;
>>>> +
>>>> + /* save current mpp configuration */
>>>> + kirkwood_mpp_save();
>>>> +
>>>> + /* finally set chosen mpp spi configuration */
>>>> + kirkwood_mpp_conf(spi_mpp_config);
>>>> +
>>>> return 0;
>>>> }
>>>>
>>>> void spi_release_bus(struct spi_slave *slave)
>>>> {
>>>> + kirkwood_mpp_restore();
>>>> }
>>>>
>>>> #ifndef CONFIG_SPI_CS_IS_VALID
>>>> --
>>>
>>> Regards..
>>> Prafulla . . .
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