From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bo Shen <voice.shen@atmel.com>
Date: Mon, 23 Mar 2015 16:36:08 +0800
Subject: [U-Boot] question about software i2c multi instance
In-Reply-To: <20150323092828.7a22c885@amdc2363>
References: <550BEBEC.7060609@atmel.com> <20150323092828.7a22c885@amdc2363>
Message-ID: <550FD078.1040804@atmel.com>
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To: u-boot@lists.denx.de

Hi Lukasz,

On 03/23/2015 04:28 PM, Lukasz Majewski wrote:
> Hi Bo,
>
>> Hi Heiko,
>>     After check the software i2c code, I found it can not support
>> multi instances, although it has I2C_SOFT_DECLARATIONS2,
>> I2C_SOFT_DECLARATIONS3, I2C_SOFT_DECLARATIONS4.
>>     Because, when do GPIO operation, there is only one pair of
>> CONFIG_SOFT_I2C_GPIO_SCL and CONFIG_SOFT_I2C_GPIO_SDA.
>>     So, if want to support multi instances, it needs to extend the
>> GPIO configuration for SCL/SDA, am I right?
>
> Some time ago we had a similar problem with SW I2C code. Please look
> into Samsung's trats board implementation.
>
> However, such approach might be outdated, since Przemek is working on
> porting this functionality to device model:
>
> https://patchwork.ozlabs.org/patch/448460/

Thanks for your information.
Now, I just do it as following to make it work. For next step, I will 
try to switch to use DM.

--->8---
diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c
index db9b402..b9cfbb8 100644
--- a/drivers/i2c/soft_i2c.c
+++ b/drivers/i2c/soft_i2c.c
@@ -126,6 +126,13 @@ DECLARE_GLOBAL_DATA_PTR;
  #define PRINTD(fmt,args...)
  #endif

+#ifdef I2C_READ_ADAP
+static int soft_i2c_read_sda(void)
+{
+       I2C_READ_ADAP;
+}
+#endif
+
  /*-----------------------------------------------------------------------
   * Local functions
   */
@@ -256,7 +263,11 @@ static int write_byte(uchar data)
         I2C_SCL(1);
         I2C_DELAY;
         I2C_DELAY;
+#ifdef I2C_READ_ADAP
+       nack = soft_i2c_read_sda();
+#else
         nack = I2C_READ;
+#endif
         I2C_SCL(0);
         I2C_DELAY;
         I2C_ACTIVE;
@@ -286,7 +297,11 @@ static uchar read_byte(int ack)
                 I2C_SCL(1);
                 I2C_DELAY;
                 data <<= 1;
+#ifdef I2C_READ_ADAP
+               data |= soft_i2c_read_sda();
+#else
                 data |= I2C_READ;
+#endif
                 I2C_DELAY;
         }
         send_ack(ack);
---8<---

Thanks again.

Best Regards,
Bo Shen