TTY: serial/mpsc, clean up init/remove functions

There is a chain of up to 4 nested ifs in init and remove functions.
Instead, make the code linear and use goto's to handle failures.

Remove unneeded cast from mpsc_release_port by referencing pi->port
directly. And finally, use dev_dbg instead of pr_debug given we have
dev->dev node.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 79 insertions, 84 deletions

diff --git a/drivers/tty/serial/mpsc.c b/drivers/tty/serial/mpsc.c
index 363772992acc..44a23113f469 100644
--- a/drivers/tty/serial/mpsc.c
+++ b/drivers/tty/serial/mpsc.c
@@ -1891,44 +1891,39 @@ static void mpsc_shared_unmap_regs(void)
 static int mpsc_shared_drv_probe(struct platform_device *dev)
 {
         struct mpsc_shared_pdata        *pdata;
-        int                              rc = -ENODEV;
-
-        if (dev->id == 0) {
-                rc = mpsc_shared_map_regs(dev);
-                if (!rc) {
-                        pdata = (struct mpsc_shared_pdata *)
-                                dev_get_platdata(&dev->dev);
-
-                        mpsc_shared_regs.MPSC_MRR_m = pdata->mrr_val;
-                        mpsc_shared_regs.MPSC_RCRR_m= pdata->rcrr_val;
-                        mpsc_shared_regs.MPSC_TCRR_m= pdata->tcrr_val;
-                        mpsc_shared_regs.SDMA_INTR_CAUSE_m =
-                                pdata->intr_cause_val;
-                        mpsc_shared_regs.SDMA_INTR_MASK_m =
-                                pdata->intr_mask_val;
-
-                        rc = 0;
-                }
-        }
+        int rc;
 
-        return rc;
+        if (dev->id != 0)
+                return -ENODEV;
+
+        rc = mpsc_shared_map_regs(dev);
+        if (rc)
+                return rc;
+
+        pdata = dev_get_platdata(&dev->dev);
+
+        mpsc_shared_regs.MPSC_MRR_m = pdata->mrr_val;
+        mpsc_shared_regs.MPSC_RCRR_m= pdata->rcrr_val;
+        mpsc_shared_regs.MPSC_TCRR_m= pdata->tcrr_val;
+        mpsc_shared_regs.SDMA_INTR_CAUSE_m = pdata->intr_cause_val;
+        mpsc_shared_regs.SDMA_INTR_MASK_m = pdata->intr_mask_val;
+
+        return 0;
 }
 
 static int mpsc_shared_drv_remove(struct platform_device *dev)
 {
-        int     rc = -ENODEV;
+        if (dev->id != 0)
+                return -ENODEV;
 
-        if (dev->id == 0) {
-                mpsc_shared_unmap_regs();
-                mpsc_shared_regs.MPSC_MRR_m = 0;
-                mpsc_shared_regs.MPSC_RCRR_m = 0;
-                mpsc_shared_regs.MPSC_TCRR_m = 0;
-                mpsc_shared_regs.SDMA_INTR_CAUSE_m = 0;
-                mpsc_shared_regs.SDMA_INTR_MASK_m = 0;
-                rc = 0;
-        }
+        mpsc_shared_unmap_regs();
+        mpsc_shared_regs.MPSC_MRR_m = 0;
+        mpsc_shared_regs.MPSC_RCRR_m = 0;
+        mpsc_shared_regs.MPSC_TCRR_m = 0;
+        mpsc_shared_regs.SDMA_INTR_CAUSE_m = 0;
+        mpsc_shared_regs.SDMA_INTR_MASK_m = 0;
 
-        return rc;
+        return 0;
 }
 
 static struct platform_driver mpsc_shared_driver = {
@@ -1979,10 +1974,6 @@ static int mpsc_drv_map_regs(struct mpsc_port_info *pi,
                 pi->sdma_base_p = r->start;
         } else {
                 mpsc_resource_err("SDMA base");
-                if (pi->mpsc_base) {
-                        iounmap(pi->mpsc_base);
-                        pi->mpsc_base = NULL;
-                }
                 goto err;
         }
 
@@ -1993,19 +1984,19 @@ static int mpsc_drv_map_regs(struct mpsc_port_info *pi,
                 pi->brg_base_p = r->start;
         } else {
                 mpsc_resource_err("BRG base");
-                if (pi->mpsc_base) {
-                        iounmap(pi->mpsc_base);
-                        pi->mpsc_base = NULL;
-                }
-                if (pi->sdma_base) {
-                        iounmap(pi->sdma_base);
-                        pi->sdma_base = NULL;
-                }
                 goto err;
         }
         return 0;
 
 err:
+        if (pi->sdma_base) {
+                iounmap(pi->sdma_base);
+                pi->sdma_base = NULL;
+        }
+        if (pi->mpsc_base) {
+                iounmap(pi->mpsc_base);
+                pi->mpsc_base = NULL;
+        }
         return -ENOMEM;
 }
 
@@ -2073,36 +2064,37 @@ static void mpsc_drv_get_platform_data(struct mpsc_port_info *pi,
 
 static int mpsc_drv_probe(struct platform_device *dev)
 {
-        struct mpsc_port_info   *pi;
-        int                     rc = -ENODEV;
-
-        pr_debug("mpsc_drv_probe: Adding MPSC %d\n", dev->id);
-
-        if (dev->id < MPSC_NUM_CTLRS) {
-                pi = &mpsc_ports[dev->id];
-
-                rc = mpsc_drv_map_regs(pi, dev);
-                if (!rc) {
-                        mpsc_drv_get_platform_data(pi, dev, dev->id);
-                        pi->port.dev = &dev->dev;
-
-                        rc = mpsc_make_ready(pi);
-                        if (!rc) {
-                                spin_lock_init(&pi->tx_lock);
-                                rc = uart_add_one_port(&mpsc_reg, &pi->port);
-                                if (!rc) {
-                                        rc = 0;
-                                } else {
-                                        mpsc_release_port((struct uart_port *)
-                                                        pi);
-                                        mpsc_drv_unmap_regs(pi);
-                                }
-                        } else {
-                                mpsc_drv_unmap_regs(pi);
-                        }
-                }
-        }
+        struct mpsc_port_info *pi;
+        int rc;
+
+        dev_dbg(&dev->dev, "mpsc_drv_probe: Adding MPSC %d\n", dev->id);
+
+        if (dev->id >= MPSC_NUM_CTLRS)
+                return -ENODEV;
+
+        pi = &mpsc_ports[dev->id];
+
+        rc = mpsc_drv_map_regs(pi, dev);
+        if (rc)
+                return rc;
 
+        mpsc_drv_get_platform_data(pi, dev, dev->id);
+        pi->port.dev = &dev->dev;
+
+        rc = mpsc_make_ready(pi);
+        if (rc)
+                goto err_unmap;
+
+        spin_lock_init(&pi->tx_lock);
+        rc = uart_add_one_port(&mpsc_reg, &pi->port);
+        if (rc)
+                goto err_relport;
+
+        return 0;
+err_relport:
+        mpsc_release_port(&pi->port);
+err_unmap:
+        mpsc_drv_unmap_regs(pi);
         return rc;
 }
 
@@ -2124,19 +2116,22 @@ static int __init mpsc_drv_init(void)
         memset(&mpsc_shared_regs, 0, sizeof(mpsc_shared_regs));
 
         rc = uart_register_driver(&mpsc_reg);
-        if (!rc) {
-                rc = platform_driver_register(&mpsc_shared_driver);
-                if (!rc) {
-                        rc = platform_driver_register(&mpsc_driver);
-                        if (rc) {
-                                platform_driver_unregister(&mpsc_shared_driver);
-                                uart_unregister_driver(&mpsc_reg);
-                        }
-                } else {
-                        uart_unregister_driver(&mpsc_reg);
-                }
-        }
+        if (rc)
+                return rc;
+
+        rc = platform_driver_register(&mpsc_shared_driver);
+        if (rc)
+                goto err_unreg_uart;
 
+        rc = platform_driver_register(&mpsc_driver);
+        if (rc)
+                goto err_unreg_plat;
+
+        return 0;
+err_unreg_plat:
+        platform_driver_unregister(&mpsc_shared_driver);
+err_unreg_uart:
+        uart_unregister_driver(&mpsc_reg);
         return rc;
 }
 device_initcall(mpsc_drv_init);