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Subject[PATCH RFC] c_can_pci: generic module for c_can on PCI
Date
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Alan Cox <alan@linux.intel.com>
---
drivers/net/can/c_can/Kconfig | 11 +-
drivers/net/can/c_can/Makefile | 1 +
drivers/net/can/c_can/c_can_pci.c | 221 +++++++++++++++++++++++++++++++++++++
3 files changed, 230 insertions(+), 3 deletions(-)
create mode 100644 drivers/net/can/c_can/c_can_pci.c

diff --git a/drivers/net/can/c_can/Kconfig b/drivers/net/can/c_can/Kconfig
index ffb9773..74ef97d 100644
--- a/drivers/net/can/c_can/Kconfig
+++ b/drivers/net/can/c_can/Kconfig
@@ -2,14 +2,19 @@ menuconfig CAN_C_CAN
tristate "Bosch C_CAN devices"
depends on CAN_DEV && HAS_IOMEM

-if CAN_C_CAN
-
config CAN_C_CAN_PLATFORM
tristate "Generic Platform Bus based C_CAN driver"
+ depends on CAN_C_CAN
---help---
This driver adds support for the C_CAN chips connected to
the "platform bus" (Linux abstraction for directly to the
processor attached devices) which can be found on various
boards from ST Microelectronics (http://www.st.com)
like the SPEAr1310 and SPEAr320 evaluation boards.
-endif
+
+config CAN_C_CAN_PCI
+ tristate "Generic PCI Bus based C_CAN driver"
+ depends on CAN_C_CAN
+ ---help---
+ This driver adds support for the C_CAN chips connected to
+ the PCI bus.
diff --git a/drivers/net/can/c_can/Makefile b/drivers/net/can/c_can/Makefile
index 9273f6d..ad1cc84 100644
--- a/drivers/net/can/c_can/Makefile
+++ b/drivers/net/can/c_can/Makefile
@@ -4,5 +4,6 @@

obj-$(CONFIG_CAN_C_CAN) += c_can.o
obj-$(CONFIG_CAN_C_CAN_PLATFORM) += c_can_platform.o
+obj-$(CONFIG_CAN_C_CAN_PCI) += c_can_pci.o

ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/c_can/c_can_pci.c b/drivers/net/can/c_can/c_can_pci.c
new file mode 100644
index 0000000..b635375
--- /dev/null
+++ b/drivers/net/can/c_can/c_can_pci.c
@@ -0,0 +1,221 @@
+/*
+ * Platform CAN bus driver for Bosch C_CAN controller
+ *
+ * Copyright (C) 2012 Federico Vaga <federico.vaga@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/clk.h>
+#include <linux/pci.h>
+#include <linux/can/dev.h>
+
+#include "c_can.h"
+
+enum c_can_pci_reg_align {
+ C_CAN_REG_ALIGN_16,
+ C_CAN_REG_ALIGN_32,
+};
+
+struct c_can_pci_data {
+ unsigned int reg_align; /* Set the register alignment in the memory */
+ unsigned int freq; /* Set the frequency if clk is not usable */
+};
+
+/*
+ * 16-bit c_can registers can be arranged differently in the memory
+ * architecture of different implementations. For example: 16-bit
+ * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
+ * Handle the same by providing a common read/write interface.
+ */
+static u16 c_can_pci_read_reg_aligned_to_16bit(struct c_can_priv *priv,
+ void *reg)
+{
+ return readw(reg);
+}
+
+static void c_can_pci_write_reg_aligned_to_16bit(struct c_can_priv *priv,
+ void *reg, u16 val)
+{
+ writew(val, reg);
+}
+
+static u16 c_can_pci_read_reg_aligned_to_32bit(struct c_can_priv *priv,
+ void *reg)
+{
+ return readw(reg + (long)reg - (long)priv->regs);
+}
+
+static void c_can_pci_write_reg_aligned_to_32bit(struct c_can_priv *priv,
+ void *reg, u16 val)
+{
+ writew(val, reg + (long)reg - (long)priv->regs);
+}
+
+static int __devinit c_can_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ struct c_can_pci_data *c_can_pci_data = (void *)ent->driver_data;
+ struct c_can_priv *priv;
+ struct net_device *dev;
+ void __iomem *addr;
+ struct clk *clk;
+ int ret;
+
+ ret = pci_enable_device(pdev);
+ if (ret) {
+ dev_err(&pdev->dev, "pci_enable_device FAILED\n");
+ goto out;
+ }
+
+ ret = pci_request_regions(pdev, KBUILD_MODNAME);
+ if (ret) {
+ dev_err(&pdev->dev, "pci_request_regions FAILED\n");
+ goto out_disable_device;
+ }
+
+ pci_set_master(pdev);
+ pci_enable_msi(pdev);
+
+ addr = pci_iomap(pdev, 0, pci_resource_len(pdev, 0));
+ if (!addr) {
+ dev_err(&pdev->dev,
+ "device has no PCI memory resources, "
+ "failing adapter\n");
+ ret = -ENOMEM;
+ goto out_release_regions;
+ }
+
+ /* allocate the c_can device */
+ dev = alloc_c_can_dev();
+ if (!dev) {
+ ret = -ENOMEM;
+ goto out_iounmap;
+ }
+
+ priv = netdev_priv(dev);
+ pci_set_drvdata(pdev, dev);
+ SET_NETDEV_DEV(dev, &pdev->dev);
+
+ dev->irq = pdev->irq;
+ priv->regs = addr;
+
+ if (!c_can_pci_data->freq) {
+ /* get the appropriate clk */
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "no clock defined\n");
+ ret = -ENODEV;
+ goto out_free_c_can;
+ }
+ priv->can.clock.freq = clk_get_rate(clk);
+ priv->priv = clk;
+ } else {
+ priv->can.clock.freq = c_can_pci_data->freq;
+ priv->priv = NULL;
+ }
+
+ switch (c_can_pci_data->reg_align) {
+ case C_CAN_REG_ALIGN_32:
+ priv->read_reg = c_can_pci_read_reg_aligned_to_32bit;
+ priv->write_reg = c_can_pci_write_reg_aligned_to_32bit;
+ break;
+ case C_CAN_REG_ALIGN_16:
+ default:
+ priv->read_reg = c_can_pci_read_reg_aligned_to_16bit;
+ priv->write_reg = c_can_pci_write_reg_aligned_to_16bit;
+ break;
+ }
+
+ ret = register_c_can_dev(dev);
+ if (ret) {
+ dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
+ KBUILD_MODNAME, ret);
+ goto out_free_clock;
+ }
+
+ dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
+ KBUILD_MODNAME, priv->regs, dev->irq);
+
+ return 0;
+
+out_free_clock:
+ if (!priv->priv)
+ clk_put(priv->priv);
+out_free_c_can:
+ pci_set_drvdata(pdev, NULL);
+ free_c_can_dev(dev);
+out_iounmap:
+ pci_iounmap(pdev, addr);
+out_release_regions:
+ pci_disable_msi(pdev);
+ pci_clear_master(pdev);
+ pci_release_regions(pdev);
+out_disable_device:
+ /*
+ * do not call pci_disable_device on sta2x11 because it
+ * break all other Bus masters on this EP
+ */
+ if(pdev->vendor == PCI_VENDOR_ID_STMICRO &&
+ pdev->device == PCI_DEVICE_ID_STMICRO_CAN)
+ goto out;
+ pci_disable_device(pdev);
+out:
+ return ret;
+}
+
+static void __devexit c_can_pci_remove(struct pci_dev *pdev)
+{
+ struct net_device *dev = pci_get_drvdata(pdev);
+ struct c_can_priv *priv = netdev_priv(dev);
+
+ pci_set_drvdata(pdev, NULL);
+ free_c_can_dev(dev);
+ if (!priv->priv)
+ clk_put(priv->priv);
+ pci_iounmap(pdev, priv->regs);
+ pci_disable_msi(pdev);
+ pci_clear_master(pdev);
+ pci_release_regions(pdev);
+ /*
+ * do not call pci_disable_device on sta2x11 because it
+ * break all other Bus masters on this EP
+ */
+ if(pdev->vendor == PCI_VENDOR_ID_STMICRO &&
+ pdev->device == PCI_DEVICE_ID_STMICRO_CAN)
+ return;
+ pci_disable_device(pdev);
+}
+
+static struct c_can_pci_data c_can_sta2x11= {
+ .reg_align = C_CAN_REG_ALIGN_32,
+ .freq = 52000000, /* 52 Mhz */
+};
+
+#define C_CAN_ID(_vend, _dev, _driverdata) { \
+ PCI_DEVICE(_vend, _dev), \
+ .driver_data = (unsigned long)&_driverdata, \
+}
+DEFINE_PCI_DEVICE_TABLE(c_can_pci_tbl) = {
+ C_CAN_ID(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_CAN,
+ c_can_sta2x11),
+ {},
+};
+static struct pci_driver sta2x11_pci_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = c_can_pci_tbl,
+ .probe = c_can_pci_probe,
+ .remove = __devexit_p(c_can_pci_remove),
+};
+
+module_pci_driver(sta2x11_pci_driver);
+
+MODULE_AUTHOR("Federico Vaga <federico.vaga@gmail.com>");
+MODULE_LICENSE("GPL V2");
+MODULE_DESCRIPTION("PCI CAN bus driver for Bosch C_CAN controller");
+MODULE_DEVICE_TABLE(pci, c_can_pci_tbl);
--
1.7.10.2


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