Re: [PATCH 1/1] Blackfin I2C Driver: Functional power management support

[Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>]

On Sun, Jul 27, 2008 at 02:41:54PM +0800, Bryan Wu wrote:
> From: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
> 
> PM_SUSPEND_MEM: Blackfin does not maintain register state through
> Hibernate. Save and restore peripheral base initialization during
> PM transitions.
> 
> Signed-off-by: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-bfin-twi.c |   35 ++++++++++++++++++++++++-----------
>  1 files changed, 24 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
> index 48d084b..3c855ff 100644
> --- a/drivers/i2c/busses/i2c-bfin-twi.c
> +++ b/drivers/i2c/busses/i2c-bfin-twi.c
> @@ -49,6 +49,8 @@ struct bfin_twi_iface {
>  	struct i2c_msg 		*pmsg;
>  	int			msg_num;
>  	int			cur_msg;
> +	u16			saved_clkdiv;
> +	u16			saved_control;
>  	void __iomem		*regs_base;
>  };
>  
> @@ -565,32 +567,43 @@ static u32 bfin_twi_functionality(struct i2c_adapter *adap)
>  	       I2C_FUNC_I2C;
>  }
>  
> -
>  static struct i2c_algorithm bfin_twi_algorithm = {
>  	.master_xfer   = bfin_twi_master_xfer,
>  	.smbus_xfer    = bfin_twi_smbus_xfer,
>  	.functionality = bfin_twi_functionality,
>  };
>  
> -
> -static int i2c_bfin_twi_suspend(struct platform_device *dev, pm_message_t state)
> +static int i2c_bfin_twi_suspend(struct platform_device *pdev, pm_message_t state)
>  {
> -	struct bfin_twi_iface *iface = platform_get_drvdata(dev);
> +	struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
> +
> +	iface->saved_clkdiv = read_CLKDIV(iface);
> +	iface->saved_control = read_CONTROL(iface);
> +
> +	free_irq(iface->irq, iface);
>  
>  	/* Disable TWI */
> -	write_CONTROL(iface, read_CONTROL(iface) & ~TWI_ENA);
> -	SSYNC();
> +	write_CONTROL(iface, iface->saved_control & ~TWI_ENA);

I assume removing the SSYNC() call is valid?
  
>  	return 0;
>  }
>  
> -static int i2c_bfin_twi_resume(struct platform_device *dev)
> +static int i2c_bfin_twi_resume(struct platform_device *pdev)
>  {
> -	struct bfin_twi_iface *iface = platform_get_drvdata(dev);
> +	struct bfin_twi_iface *iface = platform_get_drvdata(pdev);
>  
> -	/* Enable TWI */
> -	write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
> -	SSYNC();
> +	int rc = request_irq(iface->irq, bfin_twi_interrupt_entry,
> +		IRQF_DISABLED, pdev->name, iface);
> +	if (rc) {
> +		dev_err(&pdev->dev, "Can't get IRQ %d !\n", iface->irq);
> +		return -ENODEV;
> +	}
> +
> +	/* Resume TWI interface clock as specified */
> +	write_CLKDIV(iface, iface->saved_clkdiv);
> +
> +	/* Resume TWI */
> +	write_CONTROL(iface, iface->saved_control);
>  
>  	return 0;
>  }
> -- 
> 1.5.6

if removing the SSYNC() call is ok, then I'll queue this into
my tree which I will be requesting a pull asap.

-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

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