Add D_CAN raminit support to C_CAN driver to enable D_CAN RAM,
which holds all the message objects during transmission or
receiving of data. This initialization/de-initialization should
be done in synchronous with D_CAN clock.

In case of AM335X-EVM (active user of D_CAN driver) message RAM is
controlled through control module register for both instances. So
control module register details is required to initialization or
de-initialization of message RAM according to instance number.

Control module memory resource is obtained from D_CAN dt node and
instance number obtained from device tree aliases node.

Signed-off-by: AnilKumar Ch <anilku...@ti.com>
---
 drivers/net/can/c_can/c_can.c          |   12 +++++++++++
 drivers/net/can/c_can/c_can.h          |    3 +++
 drivers/net/can/c_can/c_can_platform.c |   34 +++++++++++++++++++++++++++++++-
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index e5180df..c15830c 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -233,6 +233,12 @@ static inline void c_can_pm_runtime_put_sync(const struct 
c_can_priv *priv)
                pm_runtime_put_sync(priv->device);
 }
 
+static inline void c_can_reset_ram(const struct c_can_priv *priv, bool enable)
+{
+       if (priv->ram_init)
+               priv->ram_init(priv, enable);
+}
+
 static inline int get_tx_next_msg_obj(const struct c_can_priv *priv)
 {
        return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) +
@@ -1090,6 +1096,7 @@ static int c_can_open(struct net_device *dev)
        struct c_can_priv *priv = netdev_priv(dev);
 
        c_can_pm_runtime_get_sync(priv);
+       c_can_reset_ram(priv, true);
 
        /* open the can device */
        err = open_candev(dev);
@@ -1118,6 +1125,7 @@ static int c_can_open(struct net_device *dev)
 exit_irq_fail:
        close_candev(dev);
 exit_open_fail:
+       c_can_reset_ram(priv, false);
        c_can_pm_runtime_put_sync(priv);
        return err;
 }
@@ -1131,6 +1139,8 @@ static int c_can_close(struct net_device *dev)
        c_can_stop(dev);
        free_irq(dev->irq, dev);
        close_candev(dev);
+
+       c_can_reset_ram(priv, false);
        c_can_pm_runtime_put_sync(priv);
 
        return 0;
@@ -1188,6 +1198,7 @@ int c_can_power_down(struct net_device *dev)
 
        c_can_stop(dev);
 
+       c_can_reset_ram(priv, false);
        c_can_pm_runtime_put_sync(priv);
 
        return 0;
@@ -1206,6 +1217,7 @@ int c_can_power_up(struct net_device *dev)
        WARN_ON(priv->type != BOSCH_D_CAN);
 
        c_can_pm_runtime_get_sync(priv);
+       c_can_reset_ram(priv, true);
 
        /* Clear PDR and INIT bits */
        val = priv->read_reg(priv, C_CAN_CTRL_EX_REG);
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index e5ed41d..419de5c 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -169,6 +169,9 @@ struct c_can_priv {
        void *priv;             /* for board-specific data */
        u16 irqstatus;
        enum c_can_dev_id type;
+       u32 __iomem *raminit_ctrlreg;
+       unsigned int instance;
+       void (*ram_init) (const struct c_can_priv *priv, bool enable);
 };
 
 struct net_device *alloc_c_can_dev(void);
diff --git a/drivers/net/can/c_can/c_can_platform.c 
b/drivers/net/can/c_can/c_can_platform.c
index ee141613..2e61d69 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -38,6 +38,8 @@
 
 #include "c_can.h"
 
+#define CAN_RAMINIT_START_MASK(i)      (1 << (i))
+
 /*
  * 16-bit c_can registers can be arranged differently in the memory
  * architecture of different implementations. For example: 16-bit
@@ -68,6 +70,24 @@ static void c_can_plat_write_reg_aligned_to_32bit(struct 
c_can_priv *priv,
        writew(val, priv->base + 2 * priv->regs[index]);
 }
 
+static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
+{
+       u32 val;
+
+       if (!priv->raminit_ctrlreg || (priv->instance < 0))
+               return;
+
+       val = readl(priv->raminit_ctrlreg);
+       if (enable) {
+               val &= ~CAN_RAMINIT_START_MASK(priv->instance);
+               val |= CAN_RAMINIT_START_MASK(priv->instance);
+               writel(val, priv->raminit_ctrlreg);
+       } else {
+               val &= ~CAN_RAMINIT_START_MASK(priv->instance);
+               writel(val, priv->raminit_ctrlreg);
+       }
+}
+
 static struct platform_device_id c_can_id_table[] = {
        [BOSCH_C_CAN_PLATFORM] = {
                .name = KBUILD_MODNAME,
@@ -99,7 +119,7 @@ static int __devinit c_can_plat_probe(struct platform_device 
*pdev)
        const struct of_device_id *match;
        const struct platform_device_id *id;
        struct pinctrl *pinctrl;
-       struct resource *mem;
+       struct resource *mem, *res;
        int irq;
        struct clk *clk;
 
@@ -178,6 +198,18 @@ static int __devinit c_can_plat_probe(struct 
platform_device *pdev)
                priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
                priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
                priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
+
+               res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+               priv->raminit_ctrlreg =
+                               devm_request_and_ioremap(&pdev->dev, res);
+               if (!priv->raminit_ctrlreg)
+                       dev_warn(&pdev->dev, "failed to obtain control 
memory\n");
+
+               if (pdev->dev.of_node)
+                       pdev->id = of_alias_get_id(pdev->dev.of_node, "d_can");
+
+               priv->instance = pdev->id;
+               priv->ram_init = c_can_hw_raminit;
                break;
        default:
                ret = -EINVAL;
-- 
1.7.9.5

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