[PATCH v2 04/12] Serial: OMAP: Add runtime pm support for omap-serial driver

Kevin Hilman khilman at ti.com
Wed May 4 16:35:20 EDT 2011


"Govindraj.R" <govindraj.raja at ti.com> writes:

> Adapts omap-serial driver to use pm_runtime api's.
>
> 1.) Populate reg values to uart port which can be used for context restore.
> 2.) Moving context_restore func to driver from serial.c
> 3.) Adding port_enable/disable func to enable/disable given uart port.
>     enable port using get_sync and disable using autosuspend.
> 4.) using runtime irq safe api to make get_sync be called from irq context.
>
> Signed-off-by: Govindraj.R <govindraj.raja at ti.com>
> ---
>  arch/arm/mach-omap2/serial.c                  |   16 ++
>  arch/arm/plat-omap/include/plat/omap-serial.h |    2 +
>  drivers/tty/serial/omap-serial.c              |  211 ++++++++++++++++++++++---
>  3 files changed, 203 insertions(+), 26 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
> index 8c1a4c7..314d82f 100644
> --- a/arch/arm/mach-omap2/serial.c
> +++ b/arch/arm/mach-omap2/serial.c
> @@ -189,6 +189,21 @@ static void omap_serial_fill_default_pads(struct omap_board_data *bdata)
>  	}
>  }
>  
> +static void omap_uart_wakeup_enable(struct platform_device *pdev, bool enable)
> +{
> +	struct omap_uart_port_info *up = pdev->dev.platform_data;
> +
> +	/* Set or clear wake-enable bit */
> +	if (up->wk_en && up->wk_mask) {
> +		u32 v = __raw_readl(up->wk_en);
> +		if (enable)
> +			v |= up->wk_mask;
> +		else
> +			v &= ~up->wk_mask;
> +		__raw_writel(v, up->wk_en);
> +	}
> +}

Rather than having the driver do this via the PRCM, can you do an
experiment?  Can you try to leave the module-level wakeup enabled all
the time in the PRCM, and the driver can then enable/disable
module-level wakeups simply by toggling ENAWAKEUP in the module's
SYSCONFIG?  If that works, than you can just use
omap_hwmod_enable_wakeup() for this and not need the above function.

>  static void omap_uart_idle_init(struct omap_uart_port_info *uart,
>  				unsigned short num)
>  {
> @@ -332,6 +347,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata)
>  
>  	pdata->uartclk = OMAP24XX_BASE_BAUD * 16;
>  	pdata->flags = UPF_BOOT_AUTOCONF;
> +	pdata->enable_wakeup = omap_uart_wakeup_enable;
>  	if (bdata->id == omap_uart_con_id)
>  		pdata->console_uart = true;
>  
> diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
> index 2ca885b..ac30de8 100644
> --- a/arch/arm/plat-omap/include/plat/omap-serial.h
> +++ b/arch/arm/plat-omap/include/plat/omap-serial.h
> @@ -65,6 +65,7 @@ struct omap_uart_port_info {
>  	unsigned int		errata;
>  	unsigned int		console_uart;
>  
> +	void (*enable_wakeup)(struct platform_device *, bool);
>  	void __iomem *wk_st;
>  	void __iomem *wk_en;
>  	u32 wk_mask;
> @@ -120,6 +121,7 @@ struct uart_omap_port {
>  	char			name[20];
>  	unsigned long		port_activity;
>  	unsigned int		errata;
> +	void (*enable_wakeup)(struct platform_device *, bool);
>  };
>  
>  #endif /* __OMAP_SERIAL_H__ */
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index 47cadf4..633dfb4 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -37,10 +37,14 @@
>  #include <linux/clk.h>
>  #include <linux/serial_core.h>
>  #include <linux/irq.h>
> +#include <linux/pm_runtime.h>
>  
>  #include <plat/dma.h>
>  #include <plat/dmtimer.h>
>  #include <plat/omap-serial.h>
> +#include <plat/omap_device.h>
> +
> +#define OMAP_UART_AUTOSUSPEND_DELAY (30 * HZ) /* Value is msecs */
>  
>  static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
>  
> @@ -94,6 +98,17 @@ serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
>  	return port->uartclk/(baud * divisor);
>  }
>  
> +static inline void serial_omap_port_disable(struct uart_omap_port *up)
> +{
> +	pm_runtime_mark_last_busy(&up->pdev->dev);
> +	pm_runtime_put_autosuspend(&up->pdev->dev);
> +}
> +
> +static inline void serial_omap_port_enable(struct uart_omap_port *up)
> +{
> +	pm_runtime_get_sync(&up->pdev->dev);
> +}
> +
>  static void serial_omap_stop_rxdma(struct uart_omap_port *up)
>  {
>  	if (up->uart_dma.rx_dma_used) {
> @@ -110,8 +125,11 @@ static void serial_omap_enable_ms(struct uart_port *port)
>  	struct uart_omap_port *up = (struct uart_omap_port *)port;
>  
>  	dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->pdev->id);
> +
> +	serial_omap_port_enable(up);
>  	up->ier |= UART_IER_MSI;
>  	serial_out(up, UART_IER, up->ier);
> +	serial_omap_port_disable(up);
>  }
>  
>  static void serial_omap_stop_tx(struct uart_port *port)
> @@ -131,21 +149,26 @@ static void serial_omap_stop_tx(struct uart_port *port)
>  		up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE;
>  	}
>  
> +	serial_omap_port_enable(up);
>  	if (up->ier & UART_IER_THRI) {
>  		up->ier &= ~UART_IER_THRI;
>  		serial_out(up, UART_IER, up->ier);
>  	}
> +
> +	serial_omap_port_disable(up);
>  }
>  
>  static void serial_omap_stop_rx(struct uart_port *port)
>  {
>  	struct uart_omap_port *up = (struct uart_omap_port *)port;
>  
> +	serial_omap_port_enable(up);
>  	if (up->use_dma)
>  		serial_omap_stop_rxdma(up);
>  	up->ier &= ~UART_IER_RLSI;
>  	up->port.read_status_mask &= ~UART_LSR_DR;
>  	serial_out(up, UART_IER, up->ier);
> +	serial_omap_port_disable(up);
>  }
>  
>  static inline void receive_chars(struct uart_omap_port *up, int *status)
> @@ -261,8 +284,10 @@ static void serial_omap_start_tx(struct uart_port *port)
>  	unsigned int start;
>  	int ret = 0;
>  
> +	serial_omap_port_enable(up);
>  	if (!up->use_dma) {
>  		serial_omap_enable_ier_thri(up);
> +		serial_omap_port_disable(up);
>  		return;
>  	}
>  
> @@ -354,9 +379,12 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
>  	unsigned int iir, lsr;
>  	unsigned long flags;
>  
> +	serial_omap_port_enable(up);
>  	iir = serial_in(up, UART_IIR);
> -	if (iir & UART_IIR_NO_INT)
> +	if (iir & UART_IIR_NO_INT) {
> +		serial_omap_port_disable(up);
>  		return IRQ_NONE;
> +	}
>  
>  	spin_lock_irqsave(&up->port.lock, flags);
>  	lsr = serial_in(up, UART_LSR);
> @@ -378,6 +406,8 @@ static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
>  		transmit_chars(up);
>  
>  	spin_unlock_irqrestore(&up->port.lock, flags);
> +	serial_omap_port_disable(up);
> +
>  	up->port_activity = jiffies;
>  	return IRQ_HANDLED;
>  }
> @@ -388,11 +418,12 @@ static unsigned int serial_omap_tx_empty(struct uart_port *port)
>  	unsigned long flags = 0;
>  	unsigned int ret = 0;
>  
> +	serial_omap_port_enable(up);
>  	dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->pdev->id);
>  	spin_lock_irqsave(&up->port.lock, flags);
>  	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
>  	spin_unlock_irqrestore(&up->port.lock, flags);
> -
> +	serial_omap_port_disable(up);
>  	return ret;
>  }
>  
> @@ -402,7 +433,10 @@ static unsigned int serial_omap_get_mctrl(struct uart_port *port)
>  	unsigned char status;
>  	unsigned int ret = 0;
>  
> +	serial_omap_port_enable(up);
>  	status = check_modem_status(up);
> +	serial_omap_port_disable(up);
> +
>  	dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->pdev->id);
>  
>  	if (status & UART_MSR_DCD)
> @@ -434,7 +468,9 @@ static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
>  		mcr |= UART_MCR_LOOP;
>  
>  	mcr |= up->mcr;
> +	serial_omap_port_enable(up);
>  	serial_out(up, UART_MCR, mcr);
> +	serial_omap_port_disable(up);
>  }
>  
>  static void serial_omap_break_ctl(struct uart_port *port, int break_state)
> @@ -443,6 +479,7 @@ static void serial_omap_break_ctl(struct uart_port *port, int break_state)
>  	unsigned long flags = 0;
>  
>  	dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->pdev->id);
> +	serial_omap_port_enable(up);
>  	spin_lock_irqsave(&up->port.lock, flags);
>  	if (break_state == -1)
>  		up->lcr |= UART_LCR_SBC;
> @@ -450,6 +487,7 @@ static void serial_omap_break_ctl(struct uart_port *port, int break_state)
>  		up->lcr &= ~UART_LCR_SBC;
>  	serial_out(up, UART_LCR, up->lcr);
>  	spin_unlock_irqrestore(&up->port.lock, flags);
> +	serial_omap_port_disable(up);
>  }
>  
>  static int serial_omap_startup(struct uart_port *port)
> @@ -468,6 +506,7 @@ static int serial_omap_startup(struct uart_port *port)
>  
>  	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->pdev->id);
>  
> +	serial_omap_port_enable(up);
>  	/*
>  	 * Clear the FIFO buffers and disable them.
>  	 * (they will be reenabled in set_termios())
> @@ -523,6 +562,7 @@ static int serial_omap_startup(struct uart_port *port)
>  	/* Enable module level wake up */
>  	serial_out(up, UART_OMAP_WER, OMAP_UART_WER_MOD_WKUP);
>  
> +	serial_omap_port_disable(up);
>  	up->port_activity = jiffies;
>  	return 0;
>  }
> @@ -533,6 +573,8 @@ static void serial_omap_shutdown(struct uart_port *port)
>  	unsigned long flags = 0;
>  
>  	dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->pdev->id);
> +
> +	serial_omap_port_enable(up);
>  	/*
>  	 * Disable interrupts from this port
>  	 */
> @@ -566,6 +608,7 @@ static void serial_omap_shutdown(struct uart_port *port)
>  			up->uart_dma.rx_buf_dma_phys);
>  		up->uart_dma.rx_buf = NULL;
>  	}
> +	serial_omap_port_disable(up);
>  	free_irq(up->port.irq, up);
>  }
>  
> @@ -671,6 +714,10 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
>  	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
>  	quot = serial_omap_get_divisor(port, baud);
>  
> +	up->dll = quot & 0xff;
> +	up->dlh = quot >> 8;
> +	up->mdr1 = UART_OMAP_MDR1_DISABLE;
> +
>  	up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
>  			UART_FCR_ENABLE_FIFO;
>  	if (up->use_dma)
> @@ -680,6 +727,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
>  	 * Ok, we're now changing the port state. Do it with
>  	 * interrupts disabled.
>  	 */
> +	serial_omap_port_enable(up);
>  	spin_lock_irqsave(&up->port.lock, flags);
>  
>  	/*
> @@ -758,8 +806,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
>  	serial_out(up, UART_MCR, up->mcr);
>  
>  	/* Protocol, Baud Rate, and Interrupt Settings */
> -
> -	serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
> +	serial_out(up, UART_OMAP_MDR1, up->mdr1);
>  	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
>  
>  	up->efr = serial_in(up, UART_EFR);
> @@ -769,8 +816,8 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
>  	serial_out(up, UART_IER, 0);
>  	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
>  
> -	serial_out(up, UART_DLL, quot & 0xff);          /* LS of divisor */
> -	serial_out(up, UART_DLM, quot >> 8);            /* MS of divisor */
> +	serial_out(up, UART_DLL, up->dll);	/* LS of divisor */
> +	serial_out(up, UART_DLM, up->dlh);	/* MS of divisor */
>  
>  	serial_out(up, UART_LCR, 0);
>  	serial_out(up, UART_IER, up->ier);
> @@ -780,9 +827,11 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
>  	serial_out(up, UART_LCR, cval);
>  
>  	if (baud > 230400 && baud != 3000000)
> -		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_13X_MODE);
> +		up->mdr1 = UART_OMAP_MDR1_13X_MODE;
>  	else
> -		serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_16X_MODE);
> +		up->mdr1 = UART_OMAP_MDR1_16X_MODE;
> +
> +	serial_out(up, UART_OMAP_MDR1, up->mdr1)
>  
>  	/* Hardware Flow Control Configuration */
>  
> @@ -810,6 +859,7 @@ serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
>  		serial_omap_configure_xonxoff(up, termios);
>  
>  	spin_unlock_irqrestore(&up->port.lock, flags);
> +	serial_omap_port_disable(up);
>  	dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->pdev->id);
>  }
>  
> @@ -821,6 +871,8 @@ serial_omap_pm(struct uart_port *port, unsigned int state,
>  	unsigned char efr;
>  
>  	dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->pdev->id);
> +
> +	serial_omap_port_enable(up);
>  	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
>  	efr = serial_in(up, UART_EFR);
>  	serial_out(up, UART_EFR, efr | UART_EFR_ECB);
> @@ -830,6 +882,10 @@ serial_omap_pm(struct uart_port *port, unsigned int state,
>  	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
>  	serial_out(up, UART_EFR, efr);
>  	serial_out(up, UART_LCR, 0);
> +	if (state)
> +		pm_runtime_put_sync(&up->pdev->dev);
> +	else
> +		serial_omap_port_disable(up);
>  }
>  
>  static void serial_omap_release_port(struct uart_port *port)
> @@ -907,25 +963,31 @@ static inline void wait_for_xmitr(struct uart_omap_port *up)
>  static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
>  {
>  	struct uart_omap_port *up = (struct uart_omap_port *)port;
> +
> +	serial_omap_port_enable(up);
>  	wait_for_xmitr(up);
>  	serial_out(up, UART_TX, ch);
> +	serial_omap_port_disable(up);
>  }
>  
>  static int serial_omap_poll_get_char(struct uart_port *port)
>  {
>  	struct uart_omap_port *up = (struct uart_omap_port *)port;
> -	unsigned int status = serial_in(up, UART_LSR);
> +	unsigned int status;
>  
> +	serial_omap_port_enable(up);
> +	status = serial_in(up, UART_LSR);
>  	if (!(status & UART_LSR_DR))
>  		return NO_POLL_CHAR;
>  
> -	return serial_in(up, UART_RX);
> +	status = serial_in(up, UART_RX);
> +	serial_omap_port_disable(up);
> +	return status;
>  }
>  
>  #endif /* CONFIG_CONSOLE_POLL */
>  
>  #ifdef CONFIG_SERIAL_OMAP_CONSOLE
> -
>  static struct uart_omap_port *serial_omap_console_ports[4];
>  
>  static struct uart_driver serial_omap_reg;
> @@ -955,6 +1017,8 @@ serial_omap_console_write(struct console *co, const char *s,
>  	else
>  		spin_lock(&up->port.lock);
>  
> +	serial_omap_port_enable(up);
> +
>  	/*
>  	 * First save the IER then disable the interrupts
>  	 */
> @@ -979,6 +1043,7 @@ serial_omap_console_write(struct console *co, const char *s,
>  	if (up->msr_saved_flags)
>  		check_modem_status(up);
>  
> +	serial_omap_port_disable(up);
>  	if (locked)
>  		spin_unlock(&up->port.lock);
>  	local_irq_restore(flags);
> @@ -1061,22 +1126,27 @@ static struct uart_driver serial_omap_reg = {
>  	.cons		= OMAP_CONSOLE,
>  };
>  
> -static int
> -serial_omap_suspend(struct platform_device *pdev, pm_message_t state)
> +static int serial_omap_suspend(struct device *dev)
>  {
> -	struct uart_omap_port *up = platform_get_drvdata(pdev);
> +	struct uart_omap_port *up = dev_get_drvdata(dev);
>  
> -	if (up)
> +	if (up) {
>  		uart_suspend_port(&serial_omap_reg, &up->port);
> +		console_trylock();
> +		serial_omap_pm(&up->port, 3, 0);
> +	}
>  	return 0;
>  }
>  
> -static int serial_omap_resume(struct platform_device *dev)
> +static int serial_omap_resume(struct device *dev)
>  {
> -	struct uart_omap_port *up = platform_get_drvdata(dev);
> +	struct uart_omap_port *up = dev_get_drvdata(dev);
>  
> -	if (up)
> +	if (up) {
>  		uart_resume_port(&serial_omap_reg, &up->port);
> +		console_unlock();
> +	}
> +
>  	return 0;
>  }
>  
> @@ -1097,6 +1167,7 @@ static void serial_omap_rx_timeout(unsigned long uart_no)
>  			serial_omap_stop_rxdma(up);
>  			up->ier |= (UART_IER_RDI | UART_IER_RLSI);
>  			serial_out(up, UART_IER, up->ier);
> +			serial_omap_port_disable(up);
>  		}
>  		return;
>  	}
> @@ -1128,6 +1199,9 @@ static void serial_omap_rx_timeout(unsigned long uart_no)
>  
>  static void uart_rx_dma_callback(int lch, u16 ch_status, void *data)
>  {
> +	struct uart_omap_port *up = (struct uart_omap_port *)data;
> +
> +	serial_omap_port_disable(up);
>  	return;
>  }
>  
> @@ -1135,6 +1209,7 @@ static int serial_omap_start_rxdma(struct uart_omap_port *up)
>  {
>  	int ret = 0;
>  
> +	serial_omap_port_enable(up);
>  	if (up->uart_dma.rx_dma_channel == -1) {
>  		ret = omap_request_dma(up->uart_dma.uart_dma_rx,
>  				"UART Rx DMA",
> @@ -1214,6 +1289,7 @@ static void uart_tx_dma_callback(int lch, u16 ch_status, void *data)
>  		serial_omap_stop_tx(&up->port);
>  		up->uart_dma.tx_dma_used = false;
>  		spin_unlock(&(up->uart_dma.tx_lock));
> +		serial_omap_port_disable(up);
>  	} else {
>  		omap_stop_dma(up->uart_dma.tx_dma_channel);
>  		serial_omap_continue_tx(up);
> @@ -1224,9 +1300,10 @@ static void uart_tx_dma_callback(int lch, u16 ch_status, void *data)
>  
>  static int serial_omap_probe(struct platform_device *pdev)
>  {
> -	struct uart_omap_port	*up;
> +	struct uart_omap_port	*up = NULL;
>  	struct resource		*mem, *irq, *dma_tx, *dma_rx;
>  	struct omap_uart_port_info *omap_up_info = pdev->dev.platform_data;
> +	struct omap_device *od;
>  	int ret = -ENOSPC;
>  
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> @@ -1276,12 +1353,20 @@ static int serial_omap_probe(struct platform_device *pdev)
>  	up->port.ops = &serial_omap_pops;
>  	up->port.line = pdev->id;
>  
> -	up->port.membase = omap_up_info->membase;
> -	up->port.mapbase = omap_up_info->mapbase;
> +	up->port.mapbase = mem->start;
> +	up->port.membase = ioremap(mem->start, mem->end - mem->start);
> +
> +	if (!up->port.membase) {
> +		dev_err(&pdev->dev, "can't ioremap UART\n");
> +		ret = -ENOMEM;
> +		goto err1;
> +	}
> +
>  	up->port.flags = omap_up_info->flags;
> -	up->port.irqflags = omap_up_info->irqflags;
>  	up->port.uartclk = omap_up_info->uartclk;
>  	up->uart_dma.uart_base = mem->start;
> +	up->errata = omap_up_info->errata;
> +	up->enable_wakeup = omap_up_info->enable_wakeup;
>  
>  	if (omap_up_info->dma_enabled) {
>  		up->uart_dma.uart_dma_tx = dma_tx->start;
> @@ -1295,18 +1380,36 @@ static int serial_omap_probe(struct platform_device *pdev)
>  		up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
>  	}
>  
> +	pm_runtime_use_autosuspend(&pdev->dev);
> +	pm_runtime_set_autosuspend_delay(&pdev->dev,
> +			OMAP_UART_AUTOSUSPEND_DELAY);
> +
> +	pm_runtime_enable(&pdev->dev);
> +	pm_runtime_irq_safe(&pdev->dev);
> +
> +	if (omap_up_info->console_uart) {
> +		od = to_omap_device(up->pdev);
> +		omap_hwmod_idle(od->hwmods[0]);

Driver should have know knowlege of the underlying hwmod.  

I assume this is here because of the usage of HWMOD_INIT_NO_IDLE and
HWMOD_INIT_NO_RESET, right?  With proper runtime PM, we should be able to
remove the need for using those flags.

Kevin

> +		serial_omap_port_enable(up);
> +		serial_omap_port_disable(up);
> +	}
> +
>  	ui[pdev->id] = up;
>  	serial_omap_add_console_port(up);
>  
>  	ret = uart_add_one_port(&serial_omap_reg, &up->port);
>  	if (ret != 0)
> -		goto do_release_region;
> +		goto err1;
>  
> +	dev_set_drvdata(&pdev->dev, up);
>  	platform_set_drvdata(pdev, up);
> +
>  	return 0;
>  err:
>  	dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n",
>  				pdev->id, __func__, ret);
> +err1:
> +	kfree(up);
>  do_release_region:
>  	release_mem_region(mem->start, (mem->end - mem->start) + 1);
>  	return ret;
> @@ -1318,20 +1421,76 @@ static int serial_omap_remove(struct platform_device *dev)
>  
>  	platform_set_drvdata(dev, NULL);
>  	if (up) {
> +		pm_runtime_disable(&up->pdev->dev);
>  		uart_remove_one_port(&serial_omap_reg, &up->port);
>  		kfree(up);
>  	}
>  	return 0;
>  }
>  
> +static void omap_uart_restore_context(struct uart_omap_port *up)
> +{
> +	u16 efr = 0;
> +
> +	serial_out(up, UART_OMAP_MDR1, up->mdr1);
> +	serial_out(up, UART_LCR, 0xBF); /* Config B mode */
> +	efr = serial_in(up, UART_EFR);
> +	serial_out(up, UART_EFR, UART_EFR_ECB);
> +	serial_out(up, UART_LCR, 0x0); /* Operational mode */
> +	serial_out(up, UART_IER, 0x0);
> +	serial_out(up, UART_LCR, 0xBF); /* Config B mode */
> +	serial_out(up, UART_DLL, up->dll);
> +	serial_out(up, UART_DLM, up->dlh);
> +	serial_out(up, UART_LCR, 0x0); /* Operational mode */
> +	serial_out(up, UART_IER, up->ier);
> +	serial_out(up, UART_FCR, up->fcr);
> +	serial_out(up, UART_LCR, 0x80);
> +	serial_out(up, UART_MCR, up->mcr);
> +	serial_out(up, UART_LCR, 0xBF); /* Config B mode */
> +	serial_out(up, UART_EFR, efr);
> +	serial_out(up, UART_LCR, UART_LCR_WLEN8);
> +	/* UART 16x mode */
> +	serial_out(up, UART_OMAP_MDR1, up->mdr1);
> +}
> +
> +static int omap_serial_runtime_suspend(struct device *dev)
> +{
> +	struct uart_omap_port *up = dev_get_drvdata(dev);
> +
> +	if (!up)
> +		goto done;
> +
> +	if (device_may_wakeup(dev))
> +		up->enable_wakeup(up->pdev, true);
> +	else
> +		up->enable_wakeup(up->pdev, false);
> +done:
> +	return 0;
> +}
> +
> +static int omap_serial_runtime_resume(struct device *dev)
> +{
> +	struct uart_omap_port *up = dev_get_drvdata(dev);
> +
> +	if (up)
> +		omap_uart_restore_context(up);
> +
> +	return 0;
> +}
> +
> +static const struct dev_pm_ops omap_serial_dev_pm_ops = {
> +	.suspend = serial_omap_suspend,
> +	.resume	= serial_omap_resume,
> +	.runtime_suspend = omap_serial_runtime_suspend,
> +	.runtime_resume = omap_serial_runtime_resume,
> +};
> +
>  static struct platform_driver serial_omap_driver = {
>  	.probe          = serial_omap_probe,
>  	.remove         = serial_omap_remove,
> -
> -	.suspend	= serial_omap_suspend,
> -	.resume		= serial_omap_resume,
>  	.driver		= {
>  		.name	= DRIVER_NAME,
> +		.pm = &omap_serial_dev_pm_ops,
>  	},
>  };



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