Re: [PATCH] pinctrl: cherryview: Add support for GMMR GPIO opregion

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Mon, 2017-03-20 at 12:19 +0100, Hans de Goede wrote:
> On some Cherry Trail devices the ASL uses the GMMR GPIO to access
> GPIOs so as to serialize MMIO accesses to GPIO registers with the
> OS, because:
> 
> "Due to a silicon issue, a shared lock must be used to prevent
> concurrent
> accesses across the 4 GPIO controllers.
> 
> See Intel Atom Z8000 Processor Series Specification Update (Rev. 005),
> errata #CHT34, for further information."
> 
> This commit adds support for this opregion, this fixes a number of
> ASL errors on my Ezpad mini3 tablet and makes the otg port device/host
> muxing which is controlled in firmware on this model work properly.

One minor (as usual) acpi -> ACPI below.

Anyway, after addressing Mika's comment:
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/pinctrl/intel/pinctrl-cherryview.c | 35
> ++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c
> b/drivers/pinctrl/intel/pinctrl-cherryview.c
> index f80134e..6253064 100644
> --- a/drivers/pinctrl/intel/pinctrl-cherryview.c
> +++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
> @@ -148,6 +148,7 @@ struct chv_community {
>  	size_t ngpio_ranges;
>  	size_t ngpios;
>  	size_t nirqs;
> +	acpi_adr_space_type acpi_space_id;
>  };
>  
>  struct chv_pin_context {
> @@ -404,6 +405,7 @@ static const struct chv_community
> southwest_community = {
>  	 * trigger GPEs.
>  	 */
>  	.nirqs = 8,
> +	.acpi_space_id = 0x91,
>  };
>  
>  static const struct pinctrl_pin_desc north_pins[] = {
> @@ -493,6 +495,7 @@ static const struct chv_community north_community
> = {
>  	 * GPEs.
>  	 */
>  	.nirqs = 8,
> +	.acpi_space_id = 0x92,
>  };
>  
>  static const struct pinctrl_pin_desc east_pins[] = {
> @@ -536,6 +539,7 @@ static const struct chv_community east_community =
> {
>  	.ngpio_ranges = ARRAY_SIZE(east_gpio_ranges),
>  	.ngpios = ARRAY_SIZE(east_pins),
>  	.nirqs = 16,
> +	.acpi_space_id = 0x93,
>  };
>  
>  static const struct pinctrl_pin_desc southeast_pins[] = {
> @@ -662,6 +666,7 @@ static const struct chv_community
> southeast_community = {
>  	.ngpio_ranges = ARRAY_SIZE(southeast_gpio_ranges),
>  	.ngpios = ARRAY_SIZE(southeast_pins),
>  	.nirqs = 16,
> +	.acpi_space_id = 0x94,
>  };
>  
>  static const struct chv_community *chv_communities[] = {
> @@ -1586,11 +1591,34 @@ static int chv_gpio_probe(struct chv_pinctrl
> *pctrl, int irq)
>  	return 0;
>  }
>  
> +static acpi_status chv_pinctrl_mmio_access_handler(u32 function,
> +	acpi_physical_address address, u32 bits, u64 *value,
> +	void *handler_context, void *region_context)
> +{
> +	struct chv_pinctrl *pctrl = region_context;
> +	unsigned long flags;
> +	acpi_status ret = AE_OK;
> +
> +	raw_spin_lock_irqsave(&chv_lock, flags);
> +
> +	if (function == ACPI_WRITE)
> +		chv_writel((u32)(*value), pctrl->regs +
> (u32)address);
> +	else if (function == ACPI_READ)
> +		*value = readl(pctrl->regs + (u32)address);
> +	else
> +		ret = AE_BAD_PARAMETER;
> +
> +	raw_spin_unlock_irqrestore(&chv_lock, flags);
> +
> +	return AE_OK;
> +}
> +
>  static int chv_pinctrl_probe(struct platform_device *pdev)
>  {
>  	struct chv_pinctrl *pctrl;
>  	struct acpi_device *adev;
>  	struct resource *res;
> +	acpi_status status;
>  	int ret, irq, i;
>  
>  	adev = ACPI_COMPANION(&pdev->dev);
> @@ -1646,6 +1674,13 @@ static int chv_pinctrl_probe(struct
> platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	status = acpi_install_address_space_handler(adev->handle,
> +					pctrl->community-
> >acpi_space_id,
> +					chv_pinctrl_mmio_access_handl
> er,
> +					NULL, pctrl);
> +	if (ACPI_FAILURE(status))
> +		dev_err(&pdev->dev, "failed to install acpi addr
> space handler\n");
> +
>  	platform_set_drvdata(pdev, pctrl);
>  
>  	return 0;

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy