lkml.org 
[lkml]   [2014]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC 5/5] tty: Update hypervisor tty drivers to use core stdout parsing code.
Date
The evh_bytechan, hvc_opal and hvc_vio drivers all open code the parsing
of the stdout node in the device tree. This patch simplifies the driver
by removing the duplicated functionality.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
---
drivers/of/base.c | 5 ++++-
drivers/tty/ehv_bytechan.c | 43 ++++---------------------------------------
drivers/tty/hvc/hvc_opal.c | 14 +++-----------
drivers/tty/hvc/hvc_vio.c | 29 ++++++++++-------------------
include/linux/of.h | 1 +
5 files changed, 22 insertions(+), 70 deletions(-)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index a5643badeb1d..f845fd05d750 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -35,7 +35,7 @@ struct device_node *of_allnodes;
EXPORT_SYMBOL(of_allnodes);
struct device_node *of_chosen;
struct device_node *of_aliases;
-static struct device_node *of_stdout;
+struct device_node *of_stdout;

static struct kset *of_kset;

@@ -1956,9 +1956,12 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
of_chosen = of_find_node_by_path("/chosen@0");

if (of_chosen) {
+ /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
const char *name = of_get_property(of_chosen, "stdout-path", NULL);
if (!name)
name = of_get_property(of_chosen, "linux,stdout-path", NULL);
+ if (!name)
+ name = of_get_property(of_aliases, "stdout", NULL);
if (name)
of_stdout = of_find_node_by_path(name);
}
diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c
index 0419b69e270f..4f485e88f60c 100644
--- a/drivers/tty/ehv_bytechan.c
+++ b/drivers/tty/ehv_bytechan.c
@@ -108,55 +108,23 @@ static void disable_tx_interrupt(struct ehv_bc_data *bc)
*
* The byte channel to be used for the console is specified via a "stdout"
* property in the /chosen node.
- *
- * For compatible with legacy device trees, we also look for a "stdout" alias.
*/
static int find_console_handle(void)
{
- struct device_node *np, *np2;
+ struct device_node *np = of_stdout;
const char *sprop = NULL;
const uint32_t *iprop;

- np = of_find_node_by_path("/chosen");
- if (np)
- sprop = of_get_property(np, "stdout-path", NULL);
-
- if (!np || !sprop) {
- of_node_put(np);
- np = of_find_node_by_name(NULL, "aliases");
- if (np)
- sprop = of_get_property(np, "stdout", NULL);
- }
-
- if (!sprop) {
- of_node_put(np);
- return 0;
- }
-
/* We don't care what the aliased node is actually called. We only
* care if it's compatible with "epapr,hv-byte-channel", because that
- * indicates that it's a byte channel node. We use a temporary
- * variable, 'np2', because we can't release 'np' until we're done with
- * 'sprop'.
+ * indicates that it's a byte channel node.
*/
- np2 = of_find_node_by_path(sprop);
- of_node_put(np);
- np = np2;
- if (!np) {
- pr_warning("ehv-bc: stdout node '%s' does not exist\n", sprop);
- return 0;
- }
-
- /* Is it a byte channel? */
- if (!of_device_is_compatible(np, "epapr,hv-byte-channel")) {
- of_node_put(np);
+ if (!np || !of_device_is_compatible(np, "epapr,hv-byte-channel"))
return 0;
- }

stdout_irq = irq_of_parse_and_map(np, 0);
if (stdout_irq == NO_IRQ) {
- pr_err("ehv-bc: no 'interrupts' property in %s node\n", sprop);
- of_node_put(np);
+ pr_err("ehv-bc: no 'interrupts' property in %s node\n", np->full_name);
return 0;
}

@@ -167,12 +135,9 @@ static int find_console_handle(void)
if (!iprop) {
pr_err("ehv-bc: no 'hv-handle' property in %s node\n",
np->name);
- of_node_put(np);
return 0;
}
stdout_bc = be32_to_cpu(*iprop);
-
- of_node_put(np);
return 1;
}

diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index b01659bd4f7c..0ec1a80dd6a2 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -322,22 +322,14 @@ static void udbg_init_opal_common(void)

void __init hvc_opal_init_early(void)
{
- struct device_node *stdout_node = NULL;
+ struct device_node *stdout_node = of_node_get(of_stdout);
const __be32 *termno;
const char *name = NULL;
const struct hv_ops *ops;
u32 index;

- /* find the boot console from /chosen/stdout */
- if (of_chosen)
- name = of_get_property(of_chosen, "linux,stdout-path", NULL);
- if (name) {
- stdout_node = of_find_node_by_path(name);
- if (!stdout_node) {
- pr_err("hvc_opal: Failed to locate default console!\n");
- return;
- }
- } else {
+ /* If the console wasn't in /chosen, try /ibm,opal */
+ if (!stdout_node) {
struct device_node *opal, *np;

/* Current OPAL takeover doesn't provide the stdout
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c
index b594abfbf21e..5618b5fc7500 100644
--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -404,42 +404,35 @@ module_exit(hvc_vio_exit);

void __init hvc_vio_init_early(void)
{
- struct device_node *stdout_node;
const __be32 *termno;
const char *name;
const struct hv_ops *ops;

/* find the boot console from /chosen/stdout */
- if (!of_chosen)
+ if (!of_stdout)
return;
- name = of_get_property(of_chosen, "linux,stdout-path", NULL);
- if (name == NULL)
- return;
- stdout_node = of_find_node_by_path(name);
- if (!stdout_node)
- return;
- name = of_get_property(stdout_node, "name", NULL);
+ name = of_get_property(of_stdout, "name", NULL);
if (!name) {
printk(KERN_WARNING "stdout node missing 'name' property!\n");
- goto out;
+ return;
}

/* Check if it's a virtual terminal */
if (strncmp(name, "vty", 3) != 0)
- goto out;
- termno = of_get_property(stdout_node, "reg", NULL);
+ return;
+ termno = of_get_property(of_stdout, "reg", NULL);
if (termno == NULL)
- goto out;
+ return;
hvterm_priv0.termno = of_read_number(termno, 1);
spin_lock_init(&hvterm_priv0.buf_lock);
hvterm_privs[0] = &hvterm_priv0;

/* Check the protocol */
- if (of_device_is_compatible(stdout_node, "hvterm1")) {
+ if (of_device_is_compatible(of_stdout, "hvterm1")) {
hvterm_priv0.proto = HV_PROTOCOL_RAW;
ops = &hvterm_raw_ops;
}
- else if (of_device_is_compatible(stdout_node, "hvterm-protocol")) {
+ else if (of_device_is_compatible(of_stdout, "hvterm-protocol")) {
hvterm_priv0.proto = HV_PROTOCOL_HVSI;
ops = &hvterm_hvsi_ops;
hvsilib_init(&hvterm_priv0.hvsi, hvc_get_chars, hvc_put_chars,
@@ -447,7 +440,7 @@ void __init hvc_vio_init_early(void)
/* HVSI, perform the handshake now */
hvsilib_establish(&hvterm_priv0.hvsi);
} else
- goto out;
+ return;
udbg_putc = udbg_hvc_putc;
udbg_getc = udbg_hvc_getc;
udbg_getc_poll = udbg_hvc_getc_poll;
@@ -456,14 +449,12 @@ void __init hvc_vio_init_early(void)
* backend for HVSI, only do udbg
*/
if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
- goto out;
+ return;
#endif
/* Check whether the user has requested a different console. */
if (!strstr(cmd_line, "console="))
add_preferred_console("hvc", 0, NULL);
hvc_instantiate(0, 0, ops);
-out:
- of_node_put(stdout_node);
}

/* call this from early_init() for a working debug console on
diff --git a/include/linux/of.h b/include/linux/of.h
index 417945ebd8e1..1df918ee87d0 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -113,6 +113,7 @@ static inline void of_node_put(struct device_node *node) { }
extern struct device_node *of_allnodes;
extern struct device_node *of_chosen;
extern struct device_node *of_aliases;
+extern struct device_node *of_stdout;
extern raw_spinlock_t devtree_lock;

static inline bool of_have_populated_dt(void)
--
1.8.3.2


\
 
 \ /
  Last update: 2014-03-28 17:41    [W:0.189 / U:34.744 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site