[U-Boot] i2c:zynq: I2C multi-bus support on Zynq

[Michal Simek]

On 09/18/2013 06:28 PM, Michael Burr wrote:
> This amends my previous patch (of Sept. 17, 2013, 5:29 p.m):
>> Initialize both bus masters as needed in 'i2c_init'.
> The behavior of this code should be unchanged from the
> old version if CONFIG_I2C_MULTI_BUS is not defined.
> 
> According to Heiko, this driver should be ported to the new
> multibus framework (which I will try to do in the near
> future), so I don't expect this patch to be accepted now.
> I am submitting this only to make sure that the current
> iteration of my code is self-consistent (i.e. not broken!).
> This version may also be helpful to anyone who still has
> the older framework.

yes. Please clear this commit message.

> 
> Signed-off-by: Michael Burr <michael.burr at logicpd.com>
> Cc: Heiko Schocher <hs at denx.de>
> Cc: Michal Simek <monstr at monstr.eu>
> ---
>  drivers/i2c/zynq_i2c.c |   25 +++++++++++++++++++++----
>  1 file changed, 21 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/i2c/zynq_i2c.c b/drivers/i2c/zynq_i2c.c
> index 1c9ae30..6610869 100644
> --- a/drivers/i2c/zynq_i2c.c
> +++ b/drivers/i2c/zynq_i2c.c
> @@ -7,7 +7,7 @@
>   *
>   * Copyright (c) 2012-2013 Xilinx, Michal Simek
>   *
> - * SPDX-License-Identifier:    GPL-2.0+
> + * SPDX-License-Identifier:	GPL-2.0+

Probably unrelated change.

>   */
>  
>  #include <common.h>
> @@ -72,9 +72,8 @@ static struct zynq_i2c_registers *zynq_i2c;
>  /* I2C init called by cmd_i2c when doing 'i2c reset'. */
>  void i2c_init(int requested_speed, int slaveadd)
>  {
> -#ifdef CONFIG_I2C_MULTI_BUS
> -	current_bus = 0;
> -#endif

I can't see this in Tom's master branch. Which branch/repo did you used?

> +#if defined(CONFIG_I2C_MULTI_BUS) || !defined(CONFIG_ZYNQ_I2C1)
> +	/* Hard-code setup for Zynq PS I2C0 */
>  	zynq_i2c = (struct zynq_i2c_registers *)ZYNQ_I2C_BASEADDR0;
>  
>  	/* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
> @@ -84,6 +83,24 @@ void i2c_init(int requested_speed, int slaveadd)
>  	/* Enable master mode, ack, and 7-bit addressing */
>  	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_MS |
>  		ZYNQ_I2C_CONTROL_ACKEN | ZYNQ_I2C_CONTROL_NEA);
> +#endif
> +#if defined(CONFIG_I2C_MULTI_BUS) || defined(CONFIG_ZYNQ_I2C1)
> +	/* Hard-code setup for Zynq PS I2C1 */
> +	zynq_i2c = (struct zynq_i2c_registers *)ZYNQ_I2C_BASEADDR1;
> +
> +	/* 111MHz / ( (3 * 17) * 22 ) = ~100KHz */
> +	writel((16 << ZYNQ_I2C_CONTROL_DIV_B_SHIFT) |
> +		(2 << ZYNQ_I2C_CONTROL_DIV_A_SHIFT), &zynq_i2c->control);
> +
> +	/* Enable master mode, ack, and 7-bit addressing */
> +	setbits_le32(&zynq_i2c->control, ZYNQ_I2C_CONTROL_MS |
> +		ZYNQ_I2C_CONTROL_ACKEN | ZYNQ_I2C_CONTROL_NEA);
> +#endif
> +#if defined(CONFIG_I2C_MULTI_BUS)
> +	/* Initially select bus '0' */
> +	zynq_i2c = (struct zynq_i2c_registers *)ZYNQ_I2C_BASEADDR0;
> +	current_bus = 0;
> +#endif

You probably have to use different logic here when you should support
both i2c controllers.

Thanks,
Michal



-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform


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