Re: [PATCH V4 3/3] mfd: da9063: MFD support for OnKey driver

[Lee Jones <lee.jones@linaro.org>]

On Tue, 12 May 2015, S Twiss wrote:

> From: Steve Twiss <stwiss.opensource@diasemi.com>
> 
> Add MFD support for the DA9063 OnKey driver
> 
> The function da9063_clear_fault_log() is added to mitigate the case of a
> hardware power-cut after a long-long OnKey press. Although there is no
> software intervention in this case (by definition) such a shutdown would
> cause persistent information within the DA9063 FAULT_LOG that would be
> available during the next device restart.
> 
> Clearance of this persistent register must be completed after such a
> hardware power-cut operation has happened so that the FAULT_LOG does not
> continue with previous values. The clearance function has been added here
> in the kernel driver because wiping the fault-log cannot be counted on
> outside the Linux kernel.
> 
> 
> Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
> 
> ---
> Version History
> 
> Changes in V4
>  - Additional description of MFD patch changes for FAULT_LOG in relation to
>    the requirements of the OnKey driver. Please see a further explanation of
>    the OnKey's operation in this thread: https://lkml.org/lkml/2015/4/29/406
> 
> Changes in V3
>  - The MFD code was originally in [PATCH V2 1/2]. This is now been moved into
>    this patch [PATCH V3 3/3].
>  - Whitespace cleanup
> 
> This patch applies against linux-next and v4.1-rc3 
> 
> 
>  drivers/mfd/da9063-core.c        | 54 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/da9063/pdata.h |  1 +
>  2 files changed, 55 insertions(+)

I'll wait to see what Dmitry has to say before applying, but for my
own reference:

Acked-by: Lee Jones <lee.jones@linaro.org>

> diff --git a/drivers/mfd/da9063-core.c b/drivers/mfd/da9063-core.c
> index facd361..af841c1 100644
> --- a/drivers/mfd/da9063-core.c
> +++ b/drivers/mfd/da9063-core.c
> @@ -60,6 +60,7 @@ static struct resource da9063_rtc_resources[] = {
>  
>  static struct resource da9063_onkey_resources[] = {
>  	{
> +		.name	= "ONKEY",
>  		.start	= DA9063_IRQ_ONKEY,
>  		.end	= DA9063_IRQ_ONKEY,
>  		.flags	= IORESOURCE_IRQ,
> @@ -97,6 +98,7 @@ static const struct mfd_cell da9063_devs[] = {
>  		.name		= DA9063_DRVNAME_ONKEY,
>  		.num_resources	= ARRAY_SIZE(da9063_onkey_resources),
>  		.resources	= da9063_onkey_resources,
> +		.of_compatible = "dlg,da9063-onkey",
>  	},
>  	{
>  		.name		= DA9063_DRVNAME_RTC,
> @@ -109,12 +111,64 @@ static const struct mfd_cell da9063_devs[] = {
>  	},
>  };
>  
> +static int da9063_clear_fault_log(struct da9063 *da9063)
> +{
> +	int ret = 0;
> +	int fault_log = 0;
> +
> +	ret = regmap_read(da9063->regmap, DA9063_REG_FAULT_LOG, &fault_log);
> +	if (ret < 0) {
> +		dev_err(da9063->dev, "Cannot read FAULT_LOG.\n");
> +		return -EIO;
> +	}
> +
> +	if (fault_log) {
> +		if (fault_log & DA9063_TWD_ERROR)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_TWD_ERROR\n");
> +		if (fault_log & DA9063_POR)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_POR\n");
> +		if (fault_log & DA9063_VDD_FAULT)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_VDD_FAULT\n");
> +		if (fault_log & DA9063_VDD_START)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_VDD_START\n");
> +		if (fault_log & DA9063_TEMP_CRIT)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_TEMP_CRIT\n");
> +		if (fault_log & DA9063_KEY_RESET)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_KEY_RESET\n");
> +		if (fault_log & DA9063_NSHUTDOWN)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_NSHUTDOWN\n");
> +		if (fault_log & DA9063_WAIT_SHUT)
> +			dev_dbg(da9063->dev,
> +				"Fault log entry detected: DA9063_WAIT_SHUT\n");
> +	}
> +
> +	ret = regmap_write(da9063->regmap,
> +			   DA9063_REG_FAULT_LOG,
> +			   fault_log);
> +	if (ret < 0)
> +		dev_err(da9063->dev,
> +			"Cannot reset FAULT_LOG values %d\n", ret);
> +
> +	return ret;
> +}
> +
>  int da9063_device_init(struct da9063 *da9063, unsigned int irq)
>  {
>  	struct da9063_pdata *pdata = da9063->dev->platform_data;
>  	int model, variant_id, variant_code;
>  	int ret;
>  
> +	ret = da9063_clear_fault_log(da9063);
> +	if (ret < 0)
> +		dev_err(da9063->dev, "Cannot clear fault log\n");
> +
>  	if (pdata) {
>  		da9063->flags = pdata->flags;
>  		da9063->irq_base = pdata->irq_base;
> diff --git a/include/linux/mfd/da9063/pdata.h b/include/linux/mfd/da9063/pdata.h
> index 95c8742..612383b 100644
> --- a/include/linux/mfd/da9063/pdata.h
> +++ b/include/linux/mfd/da9063/pdata.h
> @@ -103,6 +103,7 @@ struct da9063;
>  struct da9063_pdata {
>  	int				(*init)(struct da9063 *da9063);
>  	int				irq_base;
> +	bool				key_power;
>  	unsigned			flags;
>  	struct da9063_regulators_pdata	*regulators_pdata;
>  	struct led_platform_data	*leds_pdata;

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