NFC: nfcmrvl: add i2c driver

This driver adds the support of I2C-based Marvell NFC controller.

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

8 files changed, 353 insertions, 5 deletions

diff --git a/Documentation/devicetree/bindings/net/nfc/nfcmrvl.txt b/Documentation/devicetree/bindings/net/nfc/nfcmrvl.txt
index 7c4a0cc370cf..0fa20cc2c33c 100644
--- a/Documentation/devicetree/bindings/net/nfc/nfcmrvl.txt
+++ b/Documentation/devicetree/bindings/net/nfc/nfcmrvl.txt
@@ -1,7 +1,9 @@
 * Marvell International Ltd. NCI NFC Controller
 
 Required properties:
-- compatible: Should be "mrvl,nfc-uart".
+- compatible: Should be:
+  - "mrvl,nfc-uart" for UART devices
+  - "mrvl,nfc-i2c" for I2C devices
 
 Optional SoC specific properties:
 - pinctrl-names: Contains only one value - "default".
@@ -13,6 +15,12 @@ Optional UART-based chip specific properties:
 - flow-control: Specifies that the chip is using RTS/CTS.
 - break-control: Specifies that the chip needs specific break management.
 
+Optional I2C-based chip specific properties:
+- i2c-int-falling: Specifies that the chip read event shall be trigged on
+                   falling edge.
+- i2c-int-rising: Specifies that the chip read event shall be trigged on
+                  rising edge.
+
 Example (for ARM-based BeagleBoard Black with 88W8887 on UART5):
 
 &uart5 {
@@ -27,3 +35,27 @@ Example (for ARM-based BeagleBoard Black with 88W8887 on UART5):
                 flow-control;
         }
 };
+
+
+Example (for ARM-based BeagleBoard Black with 88W8887 on I2C1):
+
+&i2c1 {
+        status = "okay";
+        clock-frequency = <400000>;
+
+        nfcmrvli2c0: i2c@1 {
+                compatible = "mrvl,nfc-i2c";
+
+                reg = <0x8>;
+
+                /* I2C INT configuration */
+                interrupt-parent = <&gpio3>;
+                interrupts = <21 0>;
+
+                /* I2C INT trigger configuration */
+                i2c-int-rising;
+
+                /* Reset IO */
+                reset-n-io = <&gpio3 19 0>;
+        };
+};
diff --git a/drivers/nfc/nfcmrvl/Kconfig b/drivers/nfc/nfcmrvl/Kconfig
index 19ac492bc25f..e18a979bb6d3 100644
--- a/drivers/nfc/nfcmrvl/Kconfig
+++ b/drivers/nfc/nfcmrvl/Kconfig
@@ -30,3 +30,15 @@ config NFC_MRVL_UART
 
           Say Y here to compile support for Marvell NFC-over-UART driver
           into the kernel or say M to compile it as module.
+
+config NFC_MRVL_I2C
+        tristate "Marvell NFC-over-I2C driver"
+        depends on NFC_MRVL && I2C
+        help
+          Marvell NFC-over-I2C driver.
+
+          This driver provides support for Marvell NFC-over-I2C devices.
+
+          Say Y here to compile support for Marvell NFC-over-I2C driver
+          into the kernel or say M to compile it as module.
+
diff --git a/drivers/nfc/nfcmrvl/Makefile b/drivers/nfc/nfcmrvl/Makefile
index 4554ee8e3680..895866a3ebc6 100644
--- a/drivers/nfc/nfcmrvl/Makefile
+++ b/drivers/nfc/nfcmrvl/Makefile
@@ -10,3 +10,6 @@ obj-$(CONFIG_NFC_MRVL_USB) += nfcmrvl_usb.o
 
 nfcmrvl_uart-y += uart.o
 obj-$(CONFIG_NFC_MRVL_UART) += nfcmrvl_uart.o
+
+nfcmrvl_i2c-y += i2c.o
+obj-$(CONFIG_NFC_MRVL_I2C) += nfcmrvl_i2c.o
diff --git a/drivers/nfc/nfcmrvl/i2c.c b/drivers/nfc/nfcmrvl/i2c.c
new file mode 100644
index 000000000000..7a44025bdaad
--- /dev/null
+++ b/drivers/nfc/nfcmrvl/i2c.c
@@ -0,0 +1,290 @@
+/**
+ * Marvell NFC-over-I2C driver: I2C interface related functions
+ *
+ * Copyright (C) 2015, Marvell International Ltd.
+ *
+ * This software file (the "File") is distributed by Marvell International
+ * Ltd. under the terms of the GNU General Public License Version 2, June 1991
+ * (the "License").  You may use, redistribute and/or modify this File in
+ * accordance with the terms and conditions of the License, a copy of which
+ * is available on the worldwide web at
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
+ *
+ * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
+ * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
+ * this warranty disclaimer.
+ **/
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/pm_runtime.h>
+#include <linux/nfc.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <net/nfc/nci.h>
+#include <net/nfc/nci_core.h>
+#include "nfcmrvl.h"
+
+struct nfcmrvl_i2c_drv_data {
+        unsigned long flags;
+        struct device *dev;
+        struct i2c_client *i2c;
+        struct nfcmrvl_private *priv;
+};
+
+static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
+                            struct sk_buff **skb)
+{
+        int ret;
+        struct nci_ctrl_hdr nci_hdr;
+
+        /* Read NCI header to know the payload size */
+        ret = i2c_master_recv(drv_data->i2c, (u8 *)&nci_hdr, NCI_CTRL_HDR_SIZE);
+        if (ret != NCI_CTRL_HDR_SIZE) {
+                nfc_err(&drv_data->i2c->dev, "cannot read NCI header\n");
+                return -EBADMSG;
+        }
+
+        if (nci_hdr.plen > NCI_MAX_PAYLOAD_SIZE) {
+                nfc_err(&drv_data->i2c->dev, "invalid packet payload size\n");
+                return -EBADMSG;
+        }
+
+        *skb = nci_skb_alloc(drv_data->priv->ndev,
+                             nci_hdr.plen + NCI_CTRL_HDR_SIZE, GFP_KERNEL);
+        if (!*skb)
+                return -ENOMEM;
+
+        /* Copy NCI header into the SKB */
+        memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), &nci_hdr, NCI_CTRL_HDR_SIZE);
+
+        if (nci_hdr.plen) {
+                /* Read the NCI payload */
+                ret = i2c_master_recv(drv_data->i2c,
+                                      skb_put(*skb, nci_hdr.plen),
+                                      nci_hdr.plen);
+
+                if (ret != nci_hdr.plen) {
+                        nfc_err(&drv_data->i2c->dev,
+                                "Invalid frame payload length: %u (expected %u)\n",
+                                ret, nci_hdr.plen);
+                        kfree_skb(*skb);
+                        return -EBADMSG;
+                }
+        }
+
+        return 0;
+}
+
+static irqreturn_t nfcmrvl_i2c_int_irq_thread_fn(int irq, void *drv_data_ptr)
+{
+        struct nfcmrvl_i2c_drv_data *drv_data = drv_data_ptr;
+        struct sk_buff *skb = NULL;
+        int ret;
+
+        if (!drv_data->priv)
+                return IRQ_HANDLED;
+
+        if (test_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags))
+                return IRQ_HANDLED;
+
+        ret = nfcmrvl_i2c_read(drv_data, &skb);
+
+        switch (ret) {
+        case -EREMOTEIO:
+                set_bit(NFCMRVL_PHY_ERROR, &drv_data->priv->flags);
+                break;
+        case -ENOMEM:
+        case -EBADMSG:
+                nfc_err(&drv_data->i2c->dev, "read failed %d\n", ret);
+                break;
+        default:
+                if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
+                        nfc_err(&drv_data->i2c->dev, "corrupted RX packet\n");
+                break;
+        }
+        return IRQ_HANDLED;
+}
+
+static int nfcmrvl_i2c_nci_open(struct nfcmrvl_private *priv)
+{
+        struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
+
+        if (!drv_data)
+                return -ENODEV;
+
+        return 0;
+}
+
+static int nfcmrvl_i2c_nci_close(struct nfcmrvl_private *priv)
+{
+        return 0;
+}
+
+static int nfcmrvl_i2c_nci_send(struct nfcmrvl_private *priv,
+                                struct sk_buff *skb)
+{
+        struct nfcmrvl_i2c_drv_data *drv_data = priv->drv_data;
+        int ret;
+
+        if (test_bit(NFCMRVL_PHY_ERROR, &priv->flags))
+                return -EREMOTEIO;
+
+        ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
+
+        /* Retry if chip was in standby */
+        if (ret == -EREMOTEIO) {
+                nfc_info(drv_data->dev, "chip may sleep, retry\n");
+                usleep_range(6000, 10000);
+                ret = i2c_master_send(drv_data->i2c, skb->data, skb->len);
+        }
+
+        if (ret >= 0) {
+                if (ret != skb->len) {
+                        nfc_err(drv_data->dev,
+                                "Invalid length sent: %u (expected %u)\n",
+                                ret, skb->len);
+                        ret = -EREMOTEIO;
+                } else
+                        ret = 0;
+                kfree_skb(skb);
+        }
+
+        return ret;
+}
+
+static void nfcmrvl_i2c_nci_update_config(struct nfcmrvl_private *priv,
+                                          const void *param)
+{
+}
+
+static struct nfcmrvl_if_ops i2c_ops = {
+        .nci_open = nfcmrvl_i2c_nci_open,
+        .nci_close = nfcmrvl_i2c_nci_close,
+        .nci_send = nfcmrvl_i2c_nci_send,
+        .nci_update_config = nfcmrvl_i2c_nci_update_config,
+};
+
+static int nfcmrvl_i2c_parse_dt(struct device_node *node,
+                                struct nfcmrvl_platform_data *pdata)
+{
+        int ret;
+
+        ret = nfcmrvl_parse_dt(node, pdata);
+        if (ret < 0) {
+                pr_err("Failed to get generic entries\n");
+                return ret;
+        }
+
+        if (of_find_property(node, "i2c-int-falling", NULL))
+                pdata->irq_polarity = IRQF_TRIGGER_FALLING;
+        else
+                pdata->irq_polarity = IRQF_TRIGGER_RISING;
+
+        ret = irq_of_parse_and_map(node, 0);
+        if (ret < 0) {
+                pr_err("Unable to get irq, error: %d\n", ret);
+                return ret;
+        }
+        pdata->irq = ret;
+
+        return 0;
+}
+
+static int nfcmrvl_i2c_probe(struct i2c_client *client,
+                             const struct i2c_device_id *id)
+{
+        struct nfcmrvl_i2c_drv_data *drv_data;
+        struct nfcmrvl_platform_data *pdata;
+        struct nfcmrvl_platform_data config;
+        int ret;
+
+        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
+                return -ENODEV;
+        }
+
+        drv_data = devm_kzalloc(&client->dev, sizeof(*drv_data), GFP_KERNEL);
+        if (!drv_data)
+                return -ENOMEM;
+
+        drv_data->i2c = client;
+        drv_data->dev = &client->dev;
+        drv_data->priv = NULL;
+
+        i2c_set_clientdata(client, drv_data);
+
+        pdata = client->dev.platform_data;
+
+        if (!pdata && client->dev.of_node)
+                if (nfcmrvl_i2c_parse_dt(client->dev.of_node, &config) == 0)
+                        pdata = &config;
+
+        if (!pdata)
+                return -EINVAL;
+
+        /* Request the read IRQ */
+        ret = devm_request_threaded_irq(&drv_data->i2c->dev, pdata->irq,
+                                        NULL, nfcmrvl_i2c_int_irq_thread_fn,
+                                        pdata->irq_polarity | IRQF_ONESHOT,
+                                        "nfcmrvl_i2c_int", drv_data);
+        if (ret < 0) {
+                nfc_err(&drv_data->i2c->dev,
+                        "Unable to register IRQ handler\n");
+                return ret;
+        }
+
+        drv_data->priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_I2C,
+                                                  drv_data, &i2c_ops,
+                                                  &drv_data->i2c->dev, pdata);
+
+        if (IS_ERR(drv_data->priv))
+                return PTR_ERR(drv_data->priv);
+
+        drv_data->priv->support_fw_dnld = true;
+
+        return 0;
+}
+
+static int nfcmrvl_i2c_remove(struct i2c_client *client)
+{
+        struct nfcmrvl_i2c_drv_data *drv_data = i2c_get_clientdata(client);
+
+        nfcmrvl_nci_unregister_dev(drv_data->priv);
+
+        return 0;
+}
+
+
+static const struct of_device_id of_nfcmrvl_i2c_match[] = {
+        { .compatible = "mrvl,nfc-i2c", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, of_nfcmrvl_i2c_match);
+
+static struct i2c_device_id nfcmrvl_i2c_id_table[] = {
+        { "nfcmrvl_i2c", 0 },
+        {}
+};
+MODULE_DEVICE_TABLE(i2c, nfcmrvl_i2c_id_table);
+
+static struct i2c_driver nfcmrvl_i2c_driver = {
+        .probe = nfcmrvl_i2c_probe,
+        .id_table = nfcmrvl_i2c_id_table,
+        .remove = nfcmrvl_i2c_remove,
+        .driver = {
+                .name           = "nfcmrvl_i2c",
+                .owner          = THIS_MODULE,
+                .of_match_table = of_match_ptr(of_nfcmrvl_i2c_match),
+        },
+};
+
+module_i2c_driver(nfcmrvl_i2c_driver);
+
+MODULE_AUTHOR("Marvell International Ltd.");
+MODULE_DESCRIPTION("Marvell NFC-over-I2C driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/nfc/nfcmrvl/main.c b/drivers/nfc/nfcmrvl/main.c
index a24a7ca9f33d..0c27de60a6bd 100644
--- a/drivers/nfc/nfcmrvl/main.c
+++ b/drivers/nfc/nfcmrvl/main.c
@@ -33,6 +33,9 @@ static int nfcmrvl_nci_open(struct nci_dev *ndev)
         if (test_and_set_bit(NFCMRVL_NCI_RUNNING, &priv->flags))
                 return 0;
 
+        /* Reset possible fault of previous session */
+        clear_bit(NFCMRVL_PHY_ERROR, &priv->flags);
+
         err = priv->if_ops->nci_open(priv);
 
         if (err)
@@ -226,10 +229,8 @@ 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.
-         */
+        /* Reset possible fault of previous session */
+        clear_bit(NFCMRVL_PHY_ERROR, &priv->flags);
 
         if (priv->config.reset_n_io) {
                 nfc_info(priv->dev, "reset the chip\n");
diff --git a/drivers/nfc/nfcmrvl/nfcmrvl.h b/drivers/nfc/nfcmrvl/nfcmrvl.h
index f82678be5aa9..de68ff45e49a 100644
--- a/drivers/nfc/nfcmrvl/nfcmrvl.h
+++ b/drivers/nfc/nfcmrvl/nfcmrvl.h
@@ -25,6 +25,7 @@
 
 /* Define private flags: */
 #define NFCMRVL_NCI_RUNNING                     1
+#define NFCMRVL_PHY_ERROR                       2
 
 #define NFCMRVL_EXT_COEX_ID                     0xE0
 #define NFCMRVL_NOT_ALLOWED_ID                  0xE1
diff --git a/include/linux/platform_data/nfcmrvl.h b/include/linux/platform_data/nfcmrvl.h
index ac91707dabcb..a6f9d633f5be 100644
--- a/include/linux/platform_data/nfcmrvl.h
+++ b/include/linux/platform_data/nfcmrvl.h
@@ -35,6 +35,14 @@ struct nfcmrvl_platform_data {
         unsigned int flow_control;
         /* Tell if firmware supports break control for power management */
         unsigned int break_control;
+
+
+        /*
+         * I2C specific
+         */
+
+        unsigned int irq;
+        unsigned int irq_polarity;
 };
 
 #endif /* _NFCMRVL_PTF_H_ */
diff --git a/include/net/nfc/nci.h b/include/net/nfc/nci.h
index b495825f8f49..707e3ab816c2 100644
--- a/include/net/nfc/nci.h
+++ b/include/net/nfc/nci.h
@@ -35,6 +35,7 @@
 #define NCI_MAX_NUM_RF_CONFIGS                                  10
 #define NCI_MAX_NUM_CONN                                        10
 #define NCI_MAX_PARAM_LEN                                       251
+#define NCI_MAX_PAYLOAD_SIZE                                    255
 #define NCI_MAX_PACKET_SIZE                                     258
 
 /* NCI Status Codes */