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Commit 82120032 authored by AnilKumar Ch's avatar AnilKumar Ch Committed by Marc Kleine-Budde
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can: c_can: Add d_can suspend resume support 



Adds suspend resume support to DCAN driver which enables
DCAN power down mode bit (PDR). Then DCAN will ack the local
power-down mode by setting PDA bit in STATUS register.

Signed-off-by: default avatarAnilKumar Ch <anilkumar@ti.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 4cdd34b2

drivers/net/can/c_can/c_can.c

+78 −0
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ 
#define IF_ENUM_REG_LEN		11

#define C_CAN_IFACE(reg, iface)	(C_CAN_IF1_##reg + (iface) * IF_ENUM_REG_LEN)



/* control extension register D_CAN specific */

#define CONTROL_EX_PDR		BIT(8)



/* control register */

#define CONTROL_TEST		BIT(7)

#define CONTROL_CCE		BIT(6)
@@ -65,6 +68,7 @@ 
#define TEST_BASIC		BIT(2)



/* status register */

#define STATUS_PDA		BIT(10)

#define STATUS_BOFF		BIT(7)

#define STATUS_EWARN		BIT(6)

#define STATUS_EPASS		BIT(5)
@@ -164,6 +168,9 @@ 
/* minimum timeout for checking BUSY status */

#define MIN_TIMEOUT_VALUE	6



/* Wait for ~1 sec for INIT bit */

#define INIT_WAIT_MS		1000



/* napi related */

#define C_CAN_NAPI_WEIGHT	C_CAN_MSG_OBJ_RX_NUM
@@ -1153,6 +1160,77 @@ struct net_device *alloc_c_can_dev(void) 
}

EXPORT_SYMBOL_GPL(alloc_c_can_dev);



#ifdef CONFIG_PM

int c_can_power_down(struct net_device *dev)

{

	u32 val;

	unsigned long time_out;

	struct c_can_priv *priv = netdev_priv(dev);



	if (!(dev->flags & IFF_UP))

		return 0;



	WARN_ON(priv->type != BOSCH_D_CAN);



	/* set PDR value so the device goes to power down mode */

	val = priv->read_reg(priv, C_CAN_CTRL_EX_REG);

	val |= CONTROL_EX_PDR;

	priv->write_reg(priv, C_CAN_CTRL_EX_REG, val);



	/* Wait for the PDA bit to get set */

	time_out = jiffies + msecs_to_jiffies(INIT_WAIT_MS);

	while (!(priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) &&

				time_after(time_out, jiffies))

		cpu_relax();



	if (time_after(jiffies, time_out))

		return -ETIMEDOUT;



	c_can_stop(dev);



	c_can_pm_runtime_put_sync(priv);



	return 0;

}

EXPORT_SYMBOL_GPL(c_can_power_down);



int c_can_power_up(struct net_device *dev)

{

	u32 val;

	unsigned long time_out;

	struct c_can_priv *priv = netdev_priv(dev);



	if (!(dev->flags & IFF_UP))

		return 0;



	WARN_ON(priv->type != BOSCH_D_CAN);



	c_can_pm_runtime_get_sync(priv);



	/* Clear PDR and INIT bits */

	val = priv->read_reg(priv, C_CAN_CTRL_EX_REG);

	val &= ~CONTROL_EX_PDR;

	priv->write_reg(priv, C_CAN_CTRL_EX_REG, val);

	val = priv->read_reg(priv, C_CAN_CTRL_REG);

	val &= ~CONTROL_INIT;

	priv->write_reg(priv, C_CAN_CTRL_REG, val);



	/* Wait for the PDA bit to get clear */

	time_out = jiffies + msecs_to_jiffies(INIT_WAIT_MS);

	while ((priv->read_reg(priv, C_CAN_STS_REG) & STATUS_PDA) &&

				time_after(time_out, jiffies))

		cpu_relax();



	if (time_after(jiffies, time_out))

		return -ETIMEDOUT;



	c_can_start(dev);



	return 0;

}

EXPORT_SYMBOL_GPL(c_can_power_up);

#endif



void free_c_can_dev(struct net_device *dev)

{

	free_candev(dev);

drivers/net/can/c_can/c_can.h

+8 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 


enum reg {

	C_CAN_CTRL_REG = 0,

	C_CAN_CTRL_EX_REG,

	C_CAN_STS_REG,

	C_CAN_ERR_CNT_REG,

	C_CAN_BTR_REG,
@@ -104,6 +105,7 @@ static const u16 reg_map_c_can[] = { 


static const u16 reg_map_d_can[] = {

	[C_CAN_CTRL_REG]	= 0x00,

	[C_CAN_CTRL_EX_REG]	= 0x02,

	[C_CAN_STS_REG]		= 0x04,

	[C_CAN_ERR_CNT_REG]	= 0x08,

	[C_CAN_BTR_REG]		= 0x0C,
@@ -166,6 +168,7 @@ struct c_can_priv { 
	unsigned int tx_echo;

	void *priv;		/* for board-specific data */

	u16 irqstatus;

	enum c_can_dev_id type;

};



struct net_device *alloc_c_can_dev(void);
@@ -173,4 +176,9 @@ void free_c_can_dev(struct net_device *dev); 
int register_c_can_dev(struct net_device *dev);

void unregister_c_can_dev(struct net_device *dev);



#ifdef CONFIG_PM

int c_can_power_up(struct net_device *dev);

int c_can_power_down(struct net_device *dev);

#endif



#endif /* C_CAN_H */

drivers/net/can/c_can/c_can_platform.c

+62 −0
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev) 
	priv->device = &pdev->dev;

	priv->can.clock.freq = clk_get_rate(clk);

	priv->priv = clk;

	priv->type = id->driver_data;



	platform_set_drvdata(pdev, dev);

	SET_NETDEV_DEV(dev, &pdev->dev);
@@ -232,6 +233,65 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev) 
	return 0;

}



#ifdef CONFIG_PM

static int c_can_suspend(struct platform_device *pdev, pm_message_t state)

{

	int ret;

	struct net_device *ndev = platform_get_drvdata(pdev);

	struct c_can_priv *priv = netdev_priv(ndev);



	if (priv->type != BOSCH_D_CAN) {

		dev_warn(&pdev->dev, "Not supported\n");

		return 0;

	}



	if (netif_running(ndev)) {

		netif_stop_queue(ndev);

		netif_device_detach(ndev);

	}



	ret = c_can_power_down(ndev);

	if (ret) {

		netdev_err(ndev, "failed to enter power down mode\n");

		return ret;

	}



	priv->can.state = CAN_STATE_SLEEPING;



	return 0;

}



static int c_can_resume(struct platform_device *pdev)

{

	int ret;

	struct net_device *ndev = platform_get_drvdata(pdev);

	struct c_can_priv *priv = netdev_priv(ndev);



	if (priv->type != BOSCH_D_CAN) {

		dev_warn(&pdev->dev, "Not supported\n");

		return 0;

	}



	ret = c_can_power_up(ndev);

	if (ret) {

		netdev_err(ndev, "Still in power down mode\n");

		return ret;

	}



	priv->can.state = CAN_STATE_ERROR_ACTIVE;



	if (netif_running(ndev)) {

		netif_device_attach(ndev);

		netif_start_queue(ndev);

	}



	return 0;

}

#else

#define c_can_suspend NULL

#define c_can_resume NULL

#endif



static struct platform_driver c_can_plat_driver = {

	.driver = {

		.name = KBUILD_MODNAME,
@@ -240,6 +300,8 @@ static struct platform_driver c_can_plat_driver = { 
	},

	.probe = c_can_plat_probe,

	.remove = __devexit_p(c_can_plat_remove),

	.suspend = c_can_suspend,

	.resume = c_can_resume,

	.id_table = c_can_id_table,

};