Re: [PATCH 10/12] tpm: st33zp24: Add support for acpi probing for spi device.

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Tue, Feb 09, 2016 at 10:26:59AM +0100, Christophe Ricard wrote:
> Add support for acpi probing. SMO3324 is used for st33zp24.
> It has been tested with the following acpi node on Minnowboard:
> 
> Device (TPM1)
> {
> 	Name (_ADR, Zero)  // _ADR: Address
> 	Name (_HID, "SMO3324")  // _HID: Hardware ID
> 	Name (_CID, "SMO3324")  // _CID: Compatible ID
> 	Name (_DDN, "SMO TPM")  // _DDN: DOS Device Name
> 	Name (_UID, One)  // _UID: Unique ID
> 	Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
> 	{
> 		Name (SBUF, ResourceTemplate ()
> 		{
> 			SpiSerialBus (0, PolarityLow, FourWireMode, 8,
> 				      ControllerInitiated, 10000000, ClockPolarityLow,
> 				      ClockPhaseFirst, "\\_SB.SPI1",
> 				      0x00, ResourceConsumer, ,)
> 			GpioInt (Edge, ActiveHigh, ExclusiveAndWake, PullNone, 0x0000,
> 				 "\\_SB.GPO2", 0x00, ResourceConsumer, ,)
> 			{       // Pin list
> 				0x0001
> 			}
> 			GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly,
> 				"\\_SB.GPO2", 0x00, ResourceConsumer, ,)
> 			{       // Pin list
> 				0x0002,
> 			}
> 		})
> 		Return (SBUF) /* \_SB_.SPI1.TPM1._CRS.SBUF */
> 	}
> 	Method (_STA, 0, NotSerialized)  // _STA: Status
> 	{
> 		Return (0x0F)
> 	}
> }
> 
> Signed-off-by: Christophe Ricard <christophe-h.ricard-qxv4g6HH51o@public.gmane.org>

Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>

/Jarkko

> ---
>  drivers/char/tpm/st33zp24/spi.c | 50 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/drivers/char/tpm/st33zp24/spi.c b/drivers/char/tpm/st33zp24/spi.c
> index 34cdee1..b9b74ae 100644
> --- a/drivers/char/tpm/st33zp24/spi.c
> +++ b/drivers/char/tpm/st33zp24/spi.c
> @@ -19,8 +19,10 @@
>  #include <linux/module.h>
>  #include <linux/spi/spi.h>
>  #include <linux/gpio.h>
> +#include <linux/gpio/consumer.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_gpio.h>
> +#include <linux/acpi.h>
>  #include <linux/tpm.h>
>  #include <linux/platform_data/st33zp24.h>
>  
> @@ -226,6 +228,43 @@ static const struct st33zp24_phy_ops spi_phy_ops = {
>  	.recv = st33zp24_spi_recv,
>  };
>  
> +static int st33zp24_spi_acpi_request_resources(struct st33zp24_i2c_phy *phy)
> +{
> +	struct spi_device *spi_dev = phy->spi_device;
> +	const struct acpi_device_id *id;
> +	struct gpio_desc *gpiod_lpcpd;
> +	struct device *dev;
> +
> +	if (!spi_dev)
> +		return -EINVAL;
> +
> +	dev = &spi_dev->dev;
> +
> +	/* Match the struct device against a given list of ACPI IDs */
> +	id = acpi_match_device(dev->driver->acpi_match_table, dev);
> +	if (!id)
> +		return -ENODEV;
> +
> +	/* Get LPCPD GPIO from ACPI */
> +	gpiod_lpcpd = devm_gpiod_get_index(dev, "TPM IO LPCPD", 1,
> +					   GPIOD_OUT_HIGH);
> +	if (IS_ERR(gpiod_lpcpd)) {
> +		dev_err(&client->dev,
> +			"Failed to retrieve lpcpd-gpios from acpi.\n");
> +		phy->io_lpcpd = -1;
> +		/*
> +		 * lpcpd pin is not specified. This is not an issue as
> +		 * power management can be also managed by TPM specific
> +		 * commands. So leave with a success status code.
> +		 */
> +		return 0;
> +	}
> +
> +	phy->io_lpcpd = desc_to_gpio(gpiod_lpcpd);
> +
> +	return 0;
> +}
> +
>  static int st33zp24_spi_of_request_resources(struct st33zp24_spi_phy *phy)
>  {
>  	struct device_node *pp;
> @@ -327,6 +366,10 @@ static int st33zp24_spi_probe(struct spi_device *dev)
>  		ret = st33zp24_spi_request_resources(dev, phy);
>  		if (ret)
>  			return ret;
> +	} else if (ACPI_HANDLE(&dev->dev)) {
> +		ret = st33zp24_spi_acpi_request_resources(phy);
> +		if (ret)
> +			return ret;
>  	}
>  
>  	phy->latency = st33zp24_spi_evaluate_latency(phy);
> @@ -361,6 +404,12 @@ static const struct of_device_id of_st33zp24_spi_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, of_st33zp24_spi_match);
>  
> +static const struct acpi_device_id st33zp24_spi_acpi_match[] = {
> +	{"SMO3324"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(acpi, st33zp24_spi_acpi_match);
> +
>  static SIMPLE_DEV_PM_OPS(st33zp24_spi_ops, st33zp24_pm_suspend,
>  			 st33zp24_pm_resume);
>  
> @@ -369,6 +418,7 @@ static struct spi_driver st33zp24_spi_driver = {
>  		.name = TPM_ST33_SPI,
>  		.pm = &st33zp24_spi_ops,
>  		.of_match_table = of_match_ptr(of_st33zp24_spi_match),
> +		.acpi_match_table = ACPI_PTR(st33zp24_spi_acpi_match),
>  	},
>  	.probe = st33zp24_spi_probe,
>  	.remove = st33zp24_spi_remove,
> -- 
> 2.5.0
> 

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