linux-kernel - Re: [PATCH v2 2/2] mfd: axp20x: Add support for dts property "xpowers,master-mode"

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Message-ID: <20170314161916.77ityr7jdfxtsaij@dell>
Date:   Tue, 14 Mar 2017 16:19:16 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Rask Ingemann Lambertsen <rask@...melder.dk>
Cc:     Chen-Yu Tsai <wens@...e.org>, Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] mfd: axp20x: Add support for dts property
 "xpowers,master-mode"

On Wed, 22 Feb 2017, Rask Ingemann Lambertsen wrote:

> commit b101829a029a ("mfd: axp20x: Fix AXP806 access errors on cold boot")
> was intended to fix the case where a board uses an AXP806 in slave mode,
> but the boot loader leaves it in master mode for lack of AXP806 support.
> But now the driver breaks on boards where the PMIC is operating in master
> mode. This patch lets the driver use the new device tree property
> "xpowers,master-mode" to set the correct operating mode for the board.
> 
> Fixes: 8824ee857348 ("mfd: axp20x: Add support for AXP806 PMIC")
> Signed-off-by: Rask Ingemann Lambertsen <rask@...melder.dk>
> ---
> Changes from v1 to v2:
> Changed the commit message such that Fixes: points to the commit which added
> the AXP806 driver because the property should have been included from the
> beginning of the AXP806 support.
> 
>  drivers/mfd/axp20x.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)

Applied, thanks.

> diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> index 25115fe..0512900 100644
> --- a/drivers/mfd/axp20x.c
> +++ b/drivers/mfd/axp20x.c
> @@ -31,6 +31,7 @@
>  
>  #define AXP20X_OFF	0x80
>  
> +#define AXP806_REG_ADDR_EXT_ADDR_MASTER_MODE	0
>  #define AXP806_REG_ADDR_EXT_ADDR_SLAVE_MODE	BIT(4)
>  
>  static const char * const axp20x_model_names[] = {
> @@ -877,15 +878,19 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
>  	 * the these device addressing bits (in the upper 4 bits of the
>  	 * registers) match.
>  	 *
> -	 * Since we only support an AXP806 chained to an AXP809 in slave
> -	 * mode, and there isn't any existing hardware which uses AXP806
> -	 * in master mode, or has 2 AXP806s in the same system, we can
> -	 * just program the register address extension to the slave mode
> -	 * address.
> +	 * By default we support an AXP806 chained to an AXP809 in slave
> +	 * mode. Boards which use an AXP806 in master mode can set the
> +	 * property "x-powers,master-mode" to override the default.
>  	 */
> -	if (axp20x->variant == AXP806_ID)
> -		regmap_write(axp20x->regmap, AXP806_REG_ADDR_EXT,
> -			     AXP806_REG_ADDR_EXT_ADDR_SLAVE_MODE);
> +	if (axp20x->variant == AXP806_ID) {
> +		if (of_property_read_bool(axp20x->dev->of_node,
> +					  "x-powers,master-mode"))
> +			regmap_write(axp20x->regmap, AXP806_REG_ADDR_EXT,
> +				     AXP806_REG_ADDR_EXT_ADDR_MASTER_MODE);
> +		else
> +			regmap_write(axp20x->regmap, AXP806_REG_ADDR_EXT,
> +				     AXP806_REG_ADDR_EXT_ADDR_SLAVE_MODE);
> +	}
>  
>  	ret = regmap_add_irq_chip(axp20x->regmap, axp20x->irq,
>  			  IRQF_ONESHOT | IRQF_SHARED | axp20x->irq_flags,

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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