NFC: dts: st21nfca: Add device-tree (Open Firmware) support to st21nfca

Add functions to recover hardware resources from the device-tree
when not provided by the platform data.

Based on pn544 devicetree implementation

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/nfc/st21nfca/i2c.c b/drivers/nfc/st21nfca/i2c.c
index 2337737c6cd4236f1db7d914a078a01537b94c01..3f954ed86d98e4346172e95098c985f35e8b7648 100644 (file)
--- a/drivers/nfc/st21nfca/i2c.c
+++ b/drivers/nfc/st21nfca/i2c.c
@@ -21,6 +21,8 @@
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
 #include <linux/miscdevice.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
@@ -502,11 +504,65 @@ static struct nfc_phy_ops i2c_phy_ops = {
        .disable = st21nfca_hci_i2c_disable,
 };
 
+#ifdef CONFIG_OF
+static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client)
+{
+       struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
+       struct device_node *pp;
+       int gpio;
+       int r;
+
+       pp = client->dev.of_node;
+       if (!pp)
+               return -ENODEV;
+
+       /* Get GPIO from device tree */
+       gpio = of_get_named_gpio(pp, "enable-gpios", 0);
+       if (gpio < 0) {
+               nfc_err(&client->dev, "Failed to retrieve enable-gpios from device tree\n");
+               return gpio;
+       }
+
+       /* GPIO request and configuration */
+       r = devm_gpio_request(&client->dev, gpio, "clf_enable");
+       if (r) {
+               nfc_err(&client->dev, "Failed to request enable pin\n");
+               return -ENODEV;
+       }
+
+       r = gpio_direction_output(gpio, 1);
+       if (r) {
+               nfc_err(&client->dev, "Failed to set enable pin direction as output\n");
+               return -ENODEV;
+       }
+       phy->gpio_ena = gpio;
+
+       /* IRQ */
+       r = irq_of_parse_and_map(pp, 0);
+       if (r < 0) {
+               nfc_err(&client->dev,
+                               "Unable to get irq, error: %d\n", r);
+               return r;
+       }
+
+       phy->irq_polarity = irq_get_trigger_type(r);
+       client->irq = r;
+
+       return 0;
+}
+#else
+static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client)
+{
+       return -ENODEV;
+}
+#endif
+
 static int st21nfca_hci_i2c_request_resources(struct i2c_client *client)
 {
        struct st21nfca_nfc_platform_data *pdata;
        struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
        int r;
+       int irq;
 
        pdata = client->dev.platform_data;
        if (pdata == NULL) {
@@ -547,6 +603,16 @@ static int st21nfca_hci_i2c_request_resources(struct i2c_client *client)
                }
        }
 
+       /* IRQ */
+       irq = gpio_to_irq(phy->gpio_irq);
+       if (irq < 0) {
+               nfc_err(&client->dev,
+                               "Unable to get irq number for GPIO %d error %d\n",
+                               phy->gpio_irq, r);
+               return -ENODEV;
+       }
+       client->irq = irq;
+
        return 0;
 }
 
@@ -556,7 +622,6 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client,
        struct st21nfca_i2c_phy *phy;
        struct st21nfca_nfc_platform_data *pdata;
        int r;
-       int irq;
 
        dev_dbg(&client->dev, "%s\n", __func__);
        dev_dbg(&client->dev, "IRQ: %d\n", client->irq);
@@ -585,26 +650,22 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client,
        i2c_set_clientdata(client, phy);
 
        pdata = client->dev.platform_data;
-       if (!pdata) {
-               nfc_err(&client->dev, "No platform data\n");
-               return -EINVAL;
-       }
-
-       r = st21nfca_hci_i2c_request_resources(client);
-       if (r) {
-               nfc_err(&client->dev, "Cannot get platform resources\n");
-               return r;
-       }
-
-       /* IRQ */
-       irq = gpio_to_irq(phy->gpio_irq);
-       if (irq < 0) {
-               nfc_err(&client->dev,
-                               "Unable to get irq number for GPIO %d error %d\n",
-                               phy->gpio_irq, r);
+       if (!pdata && client->dev.of_node) {
+               r = st21nfca_hci_i2c_of_request_resources(client);
+               if (r) {
+                       nfc_err(&client->dev, "No platform data\n");
+                       return r;
+               }
+       } else if (pdata) {
+               r = st21nfca_hci_i2c_request_resources(client);
+               if (r) {
+                       nfc_err(&client->dev, "Cannot get platform resources\n");
+                       return r;
+               }
+       } else {
+               nfc_err(&client->dev, "st21nfca platform resources not available\n");
                return -ENODEV;
        }
-       client->irq = irq;
 
        r = st21nfca_hci_platform_init(phy);
        if (r < 0) {
@@ -640,10 +701,17 @@ static int st21nfca_hci_i2c_remove(struct i2c_client *client)
        return 0;
 }
 
+static const struct of_device_id of_st21nfca_i2c_match[] = {
+       { .compatible = "st,st21nfca_i2c", },
+       {}
+};
+
 static struct i2c_driver st21nfca_hci_i2c_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name = ST21NFCA_HCI_I2C_DRIVER_NAME,
+               .owner = THIS_MODULE,
+               .of_match_table = of_match_ptr(of_st21nfca_i2c_match),
        },
        .probe = st21nfca_hci_i2c_probe,
        .id_table = st21nfca_hci_i2c_id_table,