[openwrt/openwrt.git] /

From a41d4af2ed4b02edca9d7f69955893d407274dc2 Mon Sep 17 00:00:00 2001
From: Shreyansh Jain <shreyansh.jain@nxp.com>
Date: Wed, 6 Jun 2018 14:19:34 +0530
Subject: [PATCH] staging: fsl_ppfe: add support for a char dev for link status

Read and IOCTL support is added. Application would need to open,
read/ioctl the /dev/pfe_us_cdev device.
select is pending as it requires a wait_queue.

Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
Signed-off-by: Calvin Johnson <calvin.johnson@nxp.com>
---
 drivers/staging/fsl_ppfe/Makefile   |   3 +-
 drivers/staging/fsl_ppfe/pfe_cdev.c | 207 ++++++++++++++++++++++++++++++++++++
 drivers/staging/fsl_ppfe/pfe_cdev.h |  52 +++++++++
 drivers/staging/fsl_ppfe/pfe_eth.c  |  14 +++
 drivers/staging/fsl_ppfe/pfe_mod.c  |  14 +++
 5 files changed, 289 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/fsl_ppfe/pfe_cdev.c
 create mode 100644 drivers/staging/fsl_ppfe/pfe_cdev.h

--- a/drivers/staging/fsl_ppfe/Makefile
+++ b/drivers/staging/fsl_ppfe/Makefile
@@ -16,4 +16,5 @@ pfe-y += pfe_mod.o \
        pfe_sysfs.o \
        pfe_debugfs.o \
        pfe_ls1012a_platform.o \
-       pfe_hal.o
+       pfe_hal.o \
+       pfe_cdev.o
--- /dev/null
+++ b/drivers/staging/fsl_ppfe/pfe_cdev.c
@@ -0,0 +1,207 @@
+/*
+ * Copyright 2018 NXP
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* @pfe_cdev.c.
+ *  Dummy device representing the PFE US in userspace.
+ *  - used for interacting with the kernel layer for link status
+ */
+
+#include "pfe_cdev.h"
+
+static int pfe_majno;
+static struct class *pfe_char_class;
+static struct device *pfe_char_dev;
+
+struct pfe_shared_info link_states[PFE_CDEV_ETH_COUNT];
+
+static int pfe_cdev_open(struct inode *inp, struct file *fp)
+{
+       pr_debug("PFE CDEV device opened.\n");
+       return 0;
+}
+
+static ssize_t pfe_cdev_read(struct file *fp, char *buf,
+                            size_t len, loff_t *off)
+{
+       int ret = 0;
+
+       pr_info("PFE CDEV attempt copying (%lu) size of user.\n",
+               sizeof(link_states));
+
+       pr_debug("Dump link_state on screen before copy_to_user\n");
+       for (; ret < PFE_CDEV_ETH_COUNT; ret++) {
+               pr_debug("%u  %u", link_states[ret].phy_id,
+                        link_states[ret].state);
+               pr_debug("\n");
+       }
+
+       /* Copy to user the value in buffer sized len */
+       ret = copy_to_user(buf, &link_states, sizeof(link_states));
+       if (ret != 0) {
+               pr_err("Failed to send (%d)bytes of (%lu) requested.\n",
+                      ret, len);
+               return -EFAULT;
+       }
+
+       /* offset set back to 0 as there is contextual reading offset */
+       *off = 0;
+       pr_debug("Read of (%lu) bytes performed.\n", sizeof(link_states));
+
+       return sizeof(link_states);
+}
+
+/**
+ * This function is for getting some commands from user through non-IOCTL
+ * channel. It can used to configure the device.
+ * TODO: To be filled in future, if require duplex communication with user
+ * space.
+ */
+static ssize_t pfe_cdev_write(struct file *fp, const char *buf,
+                             size_t len, loff_t *off)
+{
+       pr_info("PFE CDEV Write operation not supported!\n");
+
+       return -EFAULT;
+}
+
+static int pfe_cdev_release(struct inode *inp, struct file *fp)
+{
+       pr_info("PFE_CDEV: Device successfully closed\n");
+       return 0;
+}
+
+static long pfe_cdev_ioctl(struct file *fp, unsigned int cmd,
+                          unsigned long arg)
+{
+       int ret = -EFAULT;
+       int __user *argp = (int __user *)arg;
+
+       pr_debug("PFE CDEV IOCTL Called with cmd=(%u)\n", cmd);
+
+       switch (cmd) {
+       case PFE_CDEV_ETH0_STATE_GET:
+               /* Return an unsigned int (link state) for ETH0 */
+               *argp = link_states[0].state;
+               pr_debug("Returning state=%d for ETH0\n", *argp);
+               ret = 0;
+               break;
+       case PFE_CDEV_ETH1_STATE_GET:
+               /* Return an unsigned int (link state) for ETH0 */
+               *argp = link_states[1].state;
+               pr_debug("Returning state=%d for ETH1\n", *argp);
+               ret = 0;
+               break;
+       default:
+               pr_info("Unsupport cmd (%d) for PFE CDEV.\n", cmd);
+               break;
+       };
+
+       return ret;
+}
+
+static unsigned int pfe_cdev_poll(struct file *fp,
+                                 struct poll_table_struct *wait)
+{
+       pr_info("PFE CDEV poll method not supported\n");
+       return 0;
+}
+
+static const struct file_operations pfe_cdev_fops = {
+       .open = pfe_cdev_open,
+       .read = pfe_cdev_read,
+       .write = pfe_cdev_write,
+       .release = pfe_cdev_release,
+       .unlocked_ioctl = pfe_cdev_ioctl,
+       .poll = pfe_cdev_poll,
+};
+
+int pfe_cdev_init(void)
+{
+       int ret;
+
+       pr_debug("PFE CDEV initialization begin\n");
+
+       /* Register the major number for the device */
+       pfe_majno = register_chrdev(0, PFE_CDEV_NAME, &pfe_cdev_fops);
+       if (pfe_majno < 0) {
+               pr_err("Unable to register PFE CDEV. PFE CDEV not available\n");
+               ret = pfe_majno;
+               goto cleanup;
+       }
+
+       pr_debug("PFE CDEV assigned major number: %d\n", pfe_majno);
+
+       /* Register the class for the device */
+       pfe_char_class = class_create(THIS_MODULE, PFE_CLASS_NAME);
+       if (IS_ERR(pfe_char_class)) {
+               pr_err(
+               "Failed to init class for PFE CDEV. PFE CDEV not available.\n");
+               goto cleanup;
+       }
+
+       pr_debug("PFE CDEV Class created successfully.\n");
+
+       /* Create the device without any parent and without any callback data */
+           pfe_char_dev = device_create(pfe_char_class, NULL,
+                                        MKDEV(pfe_majno, 0), NULL,
+                                        PFE_CDEV_NAME);
+       if (IS_ERR(pfe_char_dev)) {
+               pr_err("Unable to PFE CDEV device. PFE CDEV not available.\n");
+               ret = PTR_ERR(pfe_char_dev);
+               goto cleanup;
+       }
+
+       /* Information structure being shared with the userspace */
+       memset(link_states, 0, sizeof(struct pfe_shared_info) *
+                       PFE_CDEV_ETH_COUNT);
+
+       pr_info("PFE CDEV created: %s\n", PFE_CDEV_NAME);
+
+       ret = 0;
+       return ret;
+
+cleanup:
+       if (!IS_ERR(pfe_char_class))
+               class_destroy(pfe_char_class);
+
+       if (pfe_majno > 0)
+               unregister_chrdev(pfe_majno, PFE_CDEV_NAME);
+
+       ret = -EFAULT;
+       return ret;
+}
+
+void pfe_cdev_exit(void)
+{
+       if (!IS_ERR(pfe_char_dev))
+               device_destroy(pfe_char_class, MKDEV(pfe_majno, 0));
+
+       if (!IS_ERR(pfe_char_class)) {
+               class_unregister(pfe_char_class);
+               class_destroy(pfe_char_class);
+       }
+
+       if (pfe_majno > 0)
+               unregister_chrdev(pfe_majno, PFE_CDEV_NAME);
+
+       /* reset the variables */
+       pfe_majno = 0;
+       pfe_char_class = NULL;
+       pfe_char_dev = NULL;
+
+       pr_info("PFE CDEV Removed.\n");
+}
--- /dev/null
+++ b/drivers/staging/fsl_ppfe/pfe_cdev.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2018 NXP
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _PFE_CDEV_H_
+#define _PFE_CDEV_H_
+
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+
+#define  PFE_CDEV_NAME "pfe_us_cdev"
+#define  PFE_CLASS_NAME  "ppfe_us"
+
+/* Extracted from ls1012a_pfe_platform_data, there are 3 interfaces which are
+ * supported by PFE driver. Should be updated if number of eth devices are
+ * changed.
+ */
+#define PFE_CDEV_ETH_COUNT 3
+
+struct pfe_shared_info {
+       uint32_t phy_id; /* Link phy ID */
+       uint8_t state;  /* Has either 0 or 1 */
+};
+
+extern struct pfe_shared_info link_states[PFE_CDEV_ETH_COUNT];
+
+/* IOCTL Commands */
+#define PFE_CDEV_ETH0_STATE_GET        0
+#define PFE_CDEV_ETH1_STATE_GET        1
+
+int pfe_cdev_init(void);
+void pfe_cdev_exit(void);
+
+#endif /* _PFE_CDEV_H_ */
--- a/drivers/staging/fsl_ppfe/pfe_eth.c
+++ b/drivers/staging/fsl_ppfe/pfe_eth.c
@@ -55,6 +55,7 @@
 
 #include "pfe_mod.h"
 #include "pfe_eth.h"
+#include "pfe_cdev.h"
 
 #define LS1012A_REV_1_0                0x87040010
 
@@ -1160,6 +1161,19 @@ static void pfe_eth_adjust_link(struct n
                phy_print_status(phydev);
 
        spin_unlock_irqrestore(&priv->lock, flags);
+
+       /* Now, dump the details to the cdev.
+        * XXX: Locking would be required? (uniprocess arch)
+        *      Or, maybe move it in spinlock above
+        */
+       if (us && priv->einfo->gem_id < PFE_CDEV_ETH_COUNT) {
+               pr_debug("Changing link state from (%u) to (%u) for ID=(%u)\n",
+                        link_states[priv->einfo->gem_id].state,
+                        phydev->link,
+                        priv->einfo->gem_id);
+               link_states[priv->einfo->gem_id].phy_id = priv->einfo->gem_id;
+               link_states[priv->einfo->gem_id].state = phydev->link;
+       }
 }
 
 /* pfe_phy_exit
--- a/drivers/staging/fsl_ppfe/pfe_mod.c
+++ b/drivers/staging/fsl_ppfe/pfe_mod.c
@@ -18,6 +18,7 @@
 
 #include <linux/dma-mapping.h>
 #include "pfe_mod.h"
+#include "pfe_cdev.h"
 
 unsigned int us;
 module_param(us, uint, 0444);
@@ -92,8 +93,18 @@ firmware_init:
        if (rc < 0)
                goto err_debugfs;
 
+       if (us) {
+               /* Creating a character device */
+               rc = pfe_cdev_init();
+               if (rc < 0)
+                       goto err_cdev;
+       }
+
        return 0;
 
+err_cdev:
+       pfe_debugfs_exit(pfe);
+
 err_debugfs:
        pfe_sysfs_exit(pfe);
 
@@ -129,6 +140,9 @@ int pfe_remove(struct pfe *pfe)
 {
        pr_info("%s\n", __func__);
 
+       if (us)
+               pfe_cdev_exit();
+
        pfe_debugfs_exit(pfe);
 
        pfe_sysfs_exit(pfe);