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OMAP2/3/4: UART: Allow per-UART disabling wakeup for serial ports
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This patch causes the OMAP uarts to honor the sysfs power/wakeup file
for IOPAD wakeups. Before the OMAP was always woken up from off mode
on a rs232 signal change.  This patch also creates a different
platform device for each serial port so that the wakeup properties can
be control per port.

By default, IOPAD wakeups are enabled for each UART.  To disable,

  # echo disabled > /sys/devices/platform/serial8250.0/power/wakeup

Where serial8250.0 can be replaced by .1, or .2 to control the other
ports.

Original idea and original patch from Russ Dill <russ.dill@gmail.com>

Cc: Russ Dill <russ.dill@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
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Kevin Hilman committed Aug 5, 2009
1 parent 2466211 commit fd455ea
Showing 1 changed file with 116 additions and 58 deletions.
174 changes: 116 additions & 58 deletions arch/arm/mach-omap2/serial.c
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Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,7 @@ struct omap_uart_state {

struct plat_serial8250_port *p;
struct list_head node;
struct platform_device pdev;

#if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_PM)
int context_valid;
Expand All @@ -68,10 +69,9 @@ struct omap_uart_state {
#endif
};

static struct omap_uart_state omap_uart[OMAP_MAX_NR_PORTS];
static LIST_HEAD(uart_list);

static struct plat_serial8250_port serial_platform_data[] = {
static struct plat_serial8250_port serial_platform_data0[] = {
{
.membase = IO_ADDRESS(OMAP_UART1_BASE),
.mapbase = OMAP_UART1_BASE,
Expand All @@ -81,6 +81,12 @@ static struct plat_serial8250_port serial_platform_data[] = {
.regshift = 2,
.uartclk = OMAP24XX_BASE_BAUD * 16,
}, {
.flags = 0
}
};

static struct plat_serial8250_port serial_platform_data1[] = {
{
.membase = IO_ADDRESS(OMAP_UART2_BASE),
.mapbase = OMAP_UART2_BASE,
.irq = 73,
Expand All @@ -89,6 +95,12 @@ static struct plat_serial8250_port serial_platform_data[] = {
.regshift = 2,
.uartclk = OMAP24XX_BASE_BAUD * 16,
}, {
.flags = 0
}
};

static struct plat_serial8250_port serial_platform_data2[] = {
{
.membase = IO_ADDRESS(OMAP_UART3_BASE),
.mapbase = OMAP_UART3_BASE,
.irq = 74,
Expand Down Expand Up @@ -217,6 +229,40 @@ static inline void omap_uart_disable_clocks(struct omap_uart_state *uart)
clk_disable(uart->fck);
}

static void omap_uart_enable_wakeup(struct omap_uart_state *uart)
{
/* Set wake-enable bit */
if (uart->wk_en && uart->wk_mask) {
u32 v = __raw_readl(uart->wk_en);
v |= uart->wk_mask;
__raw_writel(v, uart->wk_en);
}

/* Ensure IOPAD wake-enables are set */
if (cpu_is_omap34xx() && uart->padconf) {
u16 v = omap_ctrl_readw(uart->padconf);
v |= OMAP3_PADCONF_WAKEUPENABLE0;
omap_ctrl_writew(v, uart->padconf);
}
}

static void omap_uart_disable_wakeup(struct omap_uart_state *uart)
{
/* Clear wake-enable bit */
if (uart->wk_en && uart->wk_mask) {
u32 v = __raw_readl(uart->wk_en);
v &= ~uart->wk_mask;
__raw_writel(v, uart->wk_en);
}

/* Ensure IOPAD wake-enables are cleared */
if (cpu_is_omap34xx() && uart->padconf) {
u16 v = omap_ctrl_readw(uart->padconf);
v &= ~OMAP3_PADCONF_WAKEUPENABLE0;
omap_ctrl_writew(v, uart->padconf);
}
}

static void omap_uart_smart_idle_enable(struct omap_uart_state *uart,
int enable)
{
Expand Down Expand Up @@ -246,6 +292,11 @@ static void omap_uart_block_sleep(struct omap_uart_state *uart)

static void omap_uart_allow_sleep(struct omap_uart_state *uart)
{
if (device_may_wakeup(&uart->pdev.dev))
omap_uart_enable_wakeup(uart);
else
omap_uart_disable_wakeup(uart);

if (!uart->clocked)
return;

Expand Down Expand Up @@ -292,7 +343,6 @@ void omap_uart_resume_idle(int num)
/* Check for normal UART wakeup */
if (__raw_readl(uart->wk_st) & uart->wk_mask)
omap_uart_block_sleep(uart);

return;
}
}
Expand Down Expand Up @@ -346,16 +396,13 @@ 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;
struct plat_serial8250_port *p = uart->p;
int ret;

uart->can_sleep = 0;
uart->timeout = sleep_timeout;
uart->timeout = DEFAULT_TIMEOUT;
setup_timer(&uart->timer, omap_uart_idle_timer,
(unsigned long) uart);
mod_timer(&uart->timer, jiffies + uart->timeout);
Expand Down Expand Up @@ -413,22 +460,6 @@ static void omap_uart_idle_init(struct omap_uart_state *uart)
uart->padconf = 0;
}

/* Set wake-enable bit */
if (uart->wk_en && uart->wk_mask) {
v = __raw_readl(uart->wk_en);
v |= uart->wk_mask;
__raw_writel(v, uart->wk_en);
}

/* Ensure IOPAD wake-enables are set */
if (cpu_is_omap34xx() && uart->padconf) {
u16 v;

v = omap_ctrl_readw(uart->padconf);
v |= OMAP3_PADCONF_WAKEUPENABLE0;
omap_ctrl_writew(v, uart->padconf);
}

p->flags |= UPF_SHARE_IRQ;
ret = request_irq(p->irq, omap_uart_interrupt, IRQF_SHARED,
"serial idle", (void *)uart);
Expand All @@ -449,54 +480,81 @@ void omap_uart_enable_irqs(int enable)
}
}

static ssize_t sleep_timeout_show(struct kobject *kobj,
struct kobj_attribute *attr,
static ssize_t sleep_timeout_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%u\n", sleep_timeout / HZ);
struct platform_device *pdev = container_of(dev,
struct platform_device, dev);
struct omap_uart_state *uart = container_of(pdev,
struct omap_uart_state, pdev);

return sprintf(buf, "%u\n", uart->timeout / HZ);
}

static ssize_t sleep_timeout_store(struct kobject *kobj,
struct kobj_attribute *attr,
static ssize_t sleep_timeout_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t n)
{
struct omap_uart_state *uart;
struct platform_device *pdev = container_of(dev,
struct platform_device, dev);
struct omap_uart_state *uart = container_of(pdev,
struct omap_uart_state, pdev);
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);
}

uart->timeout = value * HZ;
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);

DEVICE_ATTR(sleep_timeout, 0644, sleep_timeout_show, sleep_timeout_store);
#define DEV_CREATE_FILE(dev, attr) WARN_ON(device_create_file(dev, attr))
#else
static inline void omap_uart_idle_init(struct omap_uart_state *uart) {}
#define DEV_CREATE_FILE(dev, attr)
#endif /* CONFIG_PM */

static struct platform_device serial_device = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = serial_platform_data,
static struct omap_uart_state omap_uart[OMAP_MAX_NR_PORTS] = {
{
.pdev = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = serial_platform_data0,
},
},
}, {
.pdev = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM1,
.dev = {
.platform_data = serial_platform_data1,
},
},
}, {
.pdev = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM2,
.dev = {
.platform_data = serial_platform_data2,
},
},
},
};

void __init omap_serial_init(void)
{
int i, err;
int i;
const struct omap_uart_config *info;
char name[16];

Expand All @@ -512,8 +570,10 @@ void __init omap_serial_init(void)
return;

for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
struct plat_serial8250_port *p = serial_platform_data + i;
struct omap_uart_state *uart = &omap_uart[i];
struct platform_device *pdev = &uart->pdev;
struct device *dev = &pdev->dev;
struct plat_serial8250_port *p = dev->platform_data;

if (!(info->enabled_uarts & (1 << i))) {
p->membase = NULL;
Expand Down Expand Up @@ -549,15 +609,13 @@ void __init omap_serial_init(void)
omap_uart_enable_clocks(uart);
omap_uart_reset(uart);
omap_uart_idle_init(uart);
}

err = platform_device_register(&serial_device);

#ifdef CONFIG_PM
if (!err)
err = sysfs_create_file(&serial_device.dev.kobj,
&sleep_timeout_attr.attr);
#endif

if (WARN_ON(platform_device_register(pdev)))
continue;
if ((cpu_is_omap34xx() && uart->padconf) ||
(uart->wk_en && uart->wk_mask)) {
device_init_wakeup(dev, true);
DEV_CREATE_FILE(dev, &dev_attr_sleep_timeout);
}
}
}

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