tpm: st33zp24: Add support for acpi probing for spi device.

[cascardo/linux.git] / drivers / char / tpm / st33zp24 / spi.c

diff --git a/drivers/char/tpm/st33zp24/spi.c b/drivers/char/tpm/st33zp24/spi.c
index eb351ba..173db72 100644 (file)
--- 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>
 
@@ -227,6 +229,42 @@ static const struct st33zp24_phy_ops spi_phy_ops = {
        .recv = st33zp24_spi_recv,
 };
 
+static int st33zp24_spi_acpi_request_resources(struct st33zp24_spi_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(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;
@@ -328,6 +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);
@@ -362,6 +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);
 
@@ -370,6 +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,