diff options
| author | Jouni Hogander <jouni.hogander@nokia.com> | 2008-12-09 13:36:50 +0200 |
|---|---|---|
| committer | Kevin Hilman <khilman@deeprootsystems.com> | 2009-05-28 10:59:07 -0700 |
| commit | ba87a9beae8b39894f55761f4aff5ae2ca624f81 (patch) | |
| tree | 58947da1a5ea2f46212c3460700f0175441b2be0 /arch | |
| parent | 4af4016c53f52b26461b8030211f8427a58fa5ed (diff) | |
OMAP: UART: Add sysfs interface for adjusting UART sleep timeout
This patch makes it possible to change uart sleep timeout. New sysfs
entry is added (/sys/devices/platform/serial8250.<uart>/sleep_timeout)
Writing zero will disable the timeout feature and prevent UART clocks
from being disabled.
Also default timeout is increased to 5 second to make serial console
more usable.
Original patch was written by Tero Kristo.
Cc: Tero Kristo <Tero.Kristo@nokia.com>
Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mach-omap2/serial.c | 55 |
1 files changed, 51 insertions, 4 deletions
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c index 53cbe0620286..a0a280377a8c 100644 --- a/arch/arm/mach-omap2/serial.c +++ b/arch/arm/mach-omap2/serial.c @@ -32,7 +32,7 @@ #define UART_OMAP_WER 0x17 /* Wake-up enable register */ -#define DEFAULT_TIMEOUT (2 * HZ) +#define DEFAULT_TIMEOUT (5 * HZ) struct omap_uart_state { int num; @@ -235,7 +235,10 @@ static void omap_uart_block_sleep(struct omap_uart_state *uart) omap_uart_smart_idle_enable(uart, 0); uart->can_sleep = 0; - mod_timer(&uart->timer, jiffies + uart->timeout); + if (uart->timeout) + mod_timer(&uart->timer, jiffies + uart->timeout); + else + del_timer(&uart->timer); } static void omap_uart_allow_sleep(struct omap_uart_state *uart) @@ -340,6 +343,8 @@ static irqreturn_t omap_uart_interrupt(int irq, void *dev_id) return IRQ_NONE; } +static u32 sleep_timeout = DEFAULT_TIMEOUT; + static void omap_uart_idle_init(struct omap_uart_state *uart) { u32 v; @@ -347,7 +352,7 @@ static void omap_uart_idle_init(struct omap_uart_state *uart) int ret; uart->can_sleep = 0; - uart->timeout = DEFAULT_TIMEOUT; + uart->timeout = sleep_timeout; setup_timer(&uart->timer, omap_uart_idle_timer, (unsigned long) uart); mod_timer(&uart->timer, jiffies + uart->timeout); @@ -427,6 +432,39 @@ static void omap_uart_idle_init(struct omap_uart_state *uart) WARN_ON(ret); } +static ssize_t sleep_timeout_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", sleep_timeout / HZ); +} + +static ssize_t sleep_timeout_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + struct omap_uart_state *uart; + unsigned int value; + + if (sscanf(buf, "%u", &value) != 1) { + printk(KERN_ERR "sleep_timeout_store: Invalid value\n"); + return -EINVAL; + } + sleep_timeout = value * HZ; + list_for_each_entry(uart, &uart_list, node) { + uart->timeout = sleep_timeout; + if (uart->timeout) + mod_timer(&uart->timer, jiffies + uart->timeout); + else + /* A zero value means disable timeout feature */ + omap_uart_block_sleep(uart); + } + return n; +} + +static struct kobj_attribute sleep_timeout_attr = + __ATTR(sleep_timeout, 0644, sleep_timeout_show, sleep_timeout_store); + #else static inline void omap_uart_idle_init(struct omap_uart_state *uart) {} #endif /* CONFIG_PM */ @@ -496,6 +534,15 @@ static struct platform_device serial_device = { static int __init omap_init(void) { - return platform_device_register(&serial_device); + int ret; + + ret = platform_device_register(&serial_device); + +#ifdef CONFIG_PM + if (!ret) + ret = sysfs_create_file(&serial_device.dev.kobj, + &sleep_timeout_attr.attr); +#endif + return ret; } arch_initcall(omap_init); |