From 8212003260c600b9b55a79634fb29d0f7ec813d9 Mon Sep 17 00:00:00 2001 From: AnilKumar Ch Date: Fri, 21 Sep 2012 15:29:01 +0530 Subject: [PATCH] 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: AnilKumar Ch Signed-off-by: Marc Kleine-Budde --- drivers/net/can/c_can/c_can.c | 78 ++++++++++++++++++++++++++ drivers/net/can/c_can/c_can.h | 8 +++ drivers/net/can/c_can/c_can_platform.c | 62 ++++++++++++++++++++ 3 files changed, 148 insertions(+) diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 768bb481b077..2c4a21f98442 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -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); diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h index 1437a6dbdca5..e5ed41dafa1b 100644 --- a/drivers/net/can/c_can/c_can.h +++ b/drivers/net/can/c_can/c_can.h @@ -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 */ diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c index 7b8b7a485d72..8a4e9d85a2af 100644 --- a/drivers/net/can/c_can/c_can_platform.c +++ b/drivers/net/can/c_can/c_can_platform.c @@ -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, }; -- 2.30.2