NFC: nfcmrvl: add chip reset management

Low level driver can specify a GPIO that will be used to reset
the chip. Thanks to this the driver can ensure the state of the
device at init.

Signed-off-by: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

diff --git a/drivers/nfc/nfcmrvl/main.c b/drivers/nfc/nfcmrvl/main.c
index e7f579b..708aad2 100644 (file)
--- a/drivers/nfc/nfcmrvl/main.c
+++ b/drivers/nfc/nfcmrvl/main.c
@@ -17,6 +17,8 @@
  */
 
 #include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
 #include <linux/nfc.h>
 #include <net/nfc/nci.h>
 #include <net/nfc/nci_core.h>
@@ -107,6 +109,16 @@ struct nfcmrvl_private *nfcmrvl_nci_register_dev(void *drv_data,
        priv->if_ops = ops;
        priv->dev = dev;
        priv->hci_muxed = (flags & NFCMRVL_DEV_FLAG_HCI_MUXED) ? 1 : 0;
+       priv->reset_n_io = NFCMRVL_DEV_FLAG_GET_RESET_N_IO(flags);
+
+       if (priv->reset_n_io) {
+               rc = devm_gpio_request_one(dev,
+                                          priv->reset_n_io,
+                                          GPIOF_OUT_INIT_LOW,
+                                          "nfcmrvl_reset_n");
+               if (rc < 0)
+                       nfc_err(dev, "failed to request reset_n io\n");
+       }
 
        if (priv->hci_muxed)
                headroom = NFCMRVL_HCI_EVENT_HEADER_SIZE;
@@ -127,6 +139,8 @@ struct nfcmrvl_private *nfcmrvl_nci_register_dev(void *drv_data,
 
        nci_set_drvdata(priv->ndev, priv);
 
+       nfcmrvl_chip_reset(priv);
+
        rc = nci_register_device(priv->ndev);
        if (rc) {
                nfc_err(dev, "nci_register_device failed %d\n", rc);
@@ -179,6 +193,22 @@ int nfcmrvl_nci_recv_frame(struct nfcmrvl_private *priv, struct sk_buff *skb)
 }
 EXPORT_SYMBOL_GPL(nfcmrvl_nci_recv_frame);
 
+void nfcmrvl_chip_reset(struct nfcmrvl_private *priv)
+{
+       /*
+        * This function does not take care if someone is using the device.
+        * To be improved.
+        */
+
+       if (priv->reset_n_io) {
+               nfc_info(priv->dev, "reset the chip\n");
+               gpio_set_value(priv->reset_n_io, 0);
+               usleep_range(5000, 10000);
+               gpio_set_value(priv->reset_n_io, 1);
+       } else
+               nfc_info(priv->dev, "no reset available on this interface\n");
+}
+
 MODULE_AUTHOR("Marvell International Ltd.");
 MODULE_DESCRIPTION("Marvell NFC driver ver " VERSION);
 MODULE_VERSION(VERSION);

diff --git a/drivers/nfc/nfcmrvl/nfcmrvl.h b/drivers/nfc/nfcmrvl/nfcmrvl.h
index 7a10dab..2edae9a 100644 (file)
--- a/drivers/nfc/nfcmrvl/nfcmrvl.h
+++ b/drivers/nfc/nfcmrvl/nfcmrvl.h
@@ -39,12 +39,18 @@
 #define NFCMRVL_HCI_OCF                                0xFE
 
 #define NFCMRVL_DEV_FLAG_HCI_MUXED             (1 << 0)
+#define NFCMRVL_DEV_FLAG_SET_RESET_N_IO(X)     ((X) << 16)
+#define NFCMRVL_DEV_FLAG_GET_RESET_N_IO(X)     ((X) >> 16)
 
 struct nfcmrvl_private {
 
        /* Tell if NCI packets are encapsulated in HCI ones */
        int hci_muxed;
        struct nci_dev *ndev;
+
+       /* Reset IO (0 if not available) */
+       int reset_n_io;
+
        unsigned long flags;
        void *drv_data;
        struct device *dev;
@@ -63,3 +69,5 @@ struct nfcmrvl_private *nfcmrvl_nci_register_dev(void *drv_data,
                                                 struct nfcmrvl_if_ops *ops,
                                                 struct device *dev,
                                                 unsigned int flags);
+
+void nfcmrvl_chip_reset(struct nfcmrvl_private *priv);