Re: pch_can: Data transmission stops after dropped packet

[Wolfgang Grandegger <wg@grandegger.com>]

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On 11/15/2012 10:34 PM, Michael Pellegrini wrote:
> Wolfgang Grandegger <wg <at> grandegger.com> writes:
> 
>> I need to check first if this driver can be supported with little effort.
> 
> Thank you for your consideration.

For simple out-of-tree build I have now extracted the most recent
version of c_can and c_can_pci driver files, backported it to v3.2 and
added the PCH related code.

You should be able to build these drivers on your system as shown below:

  $ tar xf c-can-pci-v1.tar.bz2
  $ cd c-can-pci-v1
  $ CONFIG_CAN_C_CAN_PCI=m \
    make -C /usr/src/linux-headers-`uname -r` SUBDIRS=`pwd` modules

This requires that you have the kernel header, gcc and fiends installed
on your system.

Then you can load the modules as shown below, after unloading the
original C_CAN modules:

  $ sudo modprobe can_dev
  $ rmmod c_can
  $ rmmod c_can_pci
  $ sudo insmod c_can.ko
  $ sudo insmod c_can_pci.ko

Hope it works as expected. 

Below is the patch I used for this driver:

From 562bbd0840e710d45ee211a0f99e5a5288dff4ba Mon Sep 17 00:00:00 2001
From: Wolfgang Grandegger <wg@grandegger.com>
Date: Sun, 18 Nov 2012 23:14:04 +0100
Subject: [PATCH] c_can_pci: first hack to get out-of-tree C_CAN_PCI driver to
 work

---
 c_can.c     |    3 +++
 c_can.h     |    1 +
 c_can_pci.c |   45 ++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/c_can.c b/c_can.c
index e5180df..23fbcd3 100644
--- a/c_can.c
+++ b/c_can.c
@@ -1106,6 +1106,9 @@ static int c_can_open(struct net_device *dev)
 		goto exit_irq_fail;
 	}
 
+	if (priv->reset)
+		priv->reset(priv);
+
 	napi_enable(&priv->napi);
 
 	/* start the c_can controller */
diff --git a/c_can.h b/c_can.h
index e5ed41d..4bad1d4 100644
--- a/c_can.h
+++ b/c_can.h
@@ -161,6 +161,7 @@ struct c_can_priv {
 	int last_status;
 	u16 (*read_reg) (struct c_can_priv *priv, enum reg index);
 	void (*write_reg) (struct c_can_priv *priv, enum reg index, u16 val);
+	void (*reset) (struct c_can_priv *priv);
 	void __iomem *base;
 	const u16 *regs;
 	unsigned long irq_flags; /* for request_irq() */
diff --git a/c_can_pci.c b/c_can_pci.c
index f8bcd73..017d008 100644
--- a/c_can_pci.c
+++ b/c_can_pci.c
@@ -21,12 +21,17 @@
 #include "c_can.h"
 
 #ifndef PCI_DEVICE_ID_STMICRO_CAN
-#define PCI_DEVICE_ID_STMICRO_CAN 0xCC11
+#define PCI_DEVICE_ID_STMICRO_CAN	0xCC11
 #endif
+#ifndef PCI_DEVICE_ID_PCH_CAN
+#define PCI_DEVICE_ID_PCH_CAN	0x8818
+#endif
+#define PCH_PCI_SOFT_RESET	0x01fc
 
 enum c_can_pci_reg_align {
 	C_CAN_REG_ALIGN_16,
 	C_CAN_REG_ALIGN_32,
+	C_CAN_REG_32,
 };
 
 struct c_can_pci_data {
@@ -36,6 +41,8 @@ struct c_can_pci_data {
 	enum c_can_pci_reg_align reg_align;
 	/* Set the frequency */
 	unsigned int freq;
+	/* CAN reset callback */
+	void (*reset) (struct c_can_priv *priv);
 };
 
 /*
@@ -68,6 +75,27 @@ static void c_can_pci_write_reg_aligned_to_32bit(struct c_can_priv *priv,
 	writew(val, priv->base + 2 * priv->regs[index]);
 }
 
+static u16 c_can_pci_read_reg_32bit(struct c_can_priv *priv,
+				    enum reg index)
+{
+	return ioread32(priv->base + 4 * priv->regs[index]);
+}
+
+static void c_can_pci_write_reg_32bit(struct c_can_priv *priv,
+				      enum reg index, u16 val)
+{
+	iowrite32(val, priv->base + 4 * priv->regs[index]);
+}
+
+static void c_can_pci_reset_pch(struct c_can_priv *priv)
+{
+	u32 __iomem *addr = (u32 __iomem *)(priv->regs + PCH_PCI_SOFT_RESET);
+
+	/* write to sw reset register */
+	iowrite32(1, addr);
+	iowrite32(0, addr);
+}
+
 static int __devinit c_can_pci_probe(struct pci_dev *pdev,
 				     const struct pci_device_id *ent)
 {
@@ -147,11 +175,17 @@ static int __devinit c_can_pci_probe(struct pci_dev *pdev,
 		priv->read_reg = c_can_pci_read_reg_aligned_to_16bit;
 		priv->write_reg = c_can_pci_write_reg_aligned_to_16bit;
 		break;
+	case C_CAN_REG_32:
+		priv->read_reg = c_can_pci_read_reg_32bit;
+		priv->write_reg = c_can_pci_write_reg_32bit;
+		break;
 	default:
 		ret = -EINVAL;
 		goto out_free_c_can;
 	}
 
+	priv->reset = c_can_pci_data->reset;
+
 	ret = register_c_can_dev(dev);
 	if (ret) {
 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
@@ -202,6 +236,13 @@ static struct c_can_pci_data c_can_sta2x11= {
 	.freq = 52000000, /* 52 Mhz */
 };
 
+static struct c_can_pci_data c_can_pch = {
+	.type = BOSCH_C_CAN,
+	.reg_align = C_CAN_REG_32,
+	.freq = 50000000, /* 50 MHz */
+	.reset = c_can_pci_reset_pch,
+};
+
 #define C_CAN_ID(_vend, _dev, _driverdata) {		\
 	PCI_DEVICE(_vend, _dev),			\
 	.driver_data = (unsigned long)&_driverdata,	\
@@ -209,6 +250,8 @@ static struct c_can_pci_data c_can_sta2x11= {
 static DEFINE_PCI_DEVICE_TABLE(c_can_pci_tbl) = {
 	C_CAN_ID(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_CAN,
 		 c_can_sta2x11),
+	C_CAN_ID(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_PCH_CAN,
+		 c_can_pch),
 	{},
 };
 static struct pci_driver c_can_pci_driver = {
-- 
1.7.9.5

Wolfgang.

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