[PATCH v2 8/8] NFC: nfcmrvl: allow gpio 0 for reset signalling

[Johan Hovold]

Allow gpio 0 to be used for reset signalling, and instead use negative
errnos to disable the reset functionality.

Signed-off-by: Johan Hovold <jo...@kernel.org>
---
 drivers/nfc/nfcmrvl/main.c            | 9 ++++-----
 include/linux/platform_data/nfcmrvl.h | 2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/nfc/nfcmrvl/main.c b/drivers/nfc/nfcmrvl/main.c
index a446590a71ca..838627fa82ee 100644
--- a/drivers/nfc/nfcmrvl/main.c
+++ b/drivers/nfc/nfcmrvl/main.c
@@ -123,12 +123,12 @@ struct nfcmrvl_private *nfcmrvl_nci_register_dev(enum 
nfcmrvl_phy phy,
 
        memcpy(&priv->config, pdata, sizeof(*pdata));
 
-       if (priv->config.reset_n_io) {
+       if (gpio_is_valid(priv->config.reset_n_io)) {
                rc = gpio_request_one(priv->config.reset_n_io,
                                      GPIOF_OUT_INIT_LOW,
                                      "nfcmrvl_reset_n");
                if (rc < 0) {
-                       priv->config.reset_n_io = 0;
+                       priv->config.reset_n_io = -EINVAL;
                        nfc_err(dev, "failed to request reset_n io\n");
                }
        }
@@ -183,7 +183,7 @@ struct nfcmrvl_private *nfcmrvl_nci_register_dev(enum 
nfcmrvl_phy phy,
 error_free_dev:
        nci_free_device(priv->ndev);
 error_free_gpio:
-       if (priv->config.reset_n_io)
+       if (gpio_is_valid(priv->config.reset_n_io))
                gpio_free(priv->config.reset_n_io);
        kfree(priv);
        return ERR_PTR(rc);
@@ -199,7 +199,7 @@ void nfcmrvl_nci_unregister_dev(struct nfcmrvl_private 
*priv)
 
        nfcmrvl_fw_dnld_deinit(priv);
 
-       if (priv->config.reset_n_io)
+       if (gpio_is_valid(priv->config.reset_n_io))
                gpio_free(priv->config.reset_n_io);
 
        nci_unregister_device(ndev);
@@ -267,7 +267,6 @@ int nfcmrvl_parse_dt(struct device_node *node,
        reset_n_io = of_get_named_gpio(node, "reset-n-io", 0);
        if (reset_n_io < 0) {
                pr_info("no reset-n-io config\n");
-               reset_n_io = 0;
        } else if (!gpio_is_valid(reset_n_io)) {
                pr_err("invalid reset-n-io GPIO\n");
                return reset_n_io;
diff --git a/include/linux/platform_data/nfcmrvl.h 
b/include/linux/platform_data/nfcmrvl.h
index a6f9d633f5be..9e75ac8d19be 100644
--- a/include/linux/platform_data/nfcmrvl.h
+++ b/include/linux/platform_data/nfcmrvl.h
@@ -23,7 +23,7 @@ struct nfcmrvl_platform_data {
         */
 
        /* GPIO that is wired to RESET_N signal */
-       unsigned int reset_n_io;
+       int reset_n_io;
        /* Tell if transport is muxed in HCI one */
        unsigned int hci_muxed;
 
-- 
2.12.2