c_can_pci: generic module for C_CAN/D_CAN on PCI
authorFederico Vaga <federico.vaga@gmail.com>
Thu, 14 Jun 2012 11:43:42 +0000 (13:43 +0200)
committerMarc Kleine-Budde <mkl@pengutronix.de>
Tue, 19 Jun 2012 19:22:28 +0000 (21:22 +0200)
Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Acked-by: Bhupesh Sharma <bhupesh.sharma@st.com>
[mkl: fix call to pci_iounmap]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
drivers/net/can/c_can/Kconfig
drivers/net/can/c_can/Makefile
drivers/net/can/c_can/c_can_pci.c [new file with mode: 0644]

index 25d371c..3b83baf 100644 (file)
@@ -13,4 +13,11 @@ config CAN_C_CAN_PLATFORM
          boards from ST Microelectronics (http://www.st.com) like the
          SPEAr1310 and SPEAr320 evaluation boards & TI (www.ti.com)
          boards like am335x, dm814x, dm813x and dm811x.
+
+config CAN_C_CAN_PCI
+       tristate "Generic PCI Bus based C_CAN/D_CAN driver"
+       depends on PCI
+       ---help---
+         This driver adds support for the C_CAN/D_CAN chips connected
+         to the PCI bus.
 endif
index 9273f6d..ad1cc84 100644 (file)
@@ -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 (file)
index 0000000..914aecf
--- /dev/null
@@ -0,0 +1,236 @@
+/*
+ * PCI bus driver for Bosch C_CAN/D_CAN controller
+ *
+ * Copyright (C) 2012 Federico Vaga <federico.vaga@gmail.com>
+ *
+ * Borrowed from c_can_platform.c
+ *
+ * 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 {
+       /* Specify if is C_CAN or D_CAN */
+       enum c_can_dev_id type;
+       /* Set the register alignment in the memory */
+       enum c_can_pci_reg_align reg_align;
+       /* Set the frequency if clk is not usable */
+       unsigned int freq;
+};
+
+/*
+ * 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,
+                                               enum reg index)
+{
+       return readw(priv->base + priv->regs[index]);
+}
+
+static void c_can_pci_write_reg_aligned_to_16bit(struct c_can_priv *priv,
+                                               enum reg index, u16 val)
+{
+       writew(val, priv->base + priv->regs[index]);
+}
+
+static u16 c_can_pci_read_reg_aligned_to_32bit(struct c_can_priv *priv,
+                                               enum reg index)
+{
+       return readw(priv->base + 2 * priv->regs[index]);
+}
+
+static void c_can_pci_write_reg_aligned_to_32bit(struct c_can_priv *priv,
+                                               enum reg index, u16 val)
+{
+       writew(val, priv->base + 2 * priv->regs[index]);
+}
+
+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->base = 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;
+       }
+
+       /* Configure CAN type */
+       switch (c_can_pci_data->type) {
+       case C_CAN_DEVTYPE:
+               priv->regs = reg_map_c_can;
+               break;
+       case D_CAN_DEVTYPE:
+               priv->regs = reg_map_d_can;
+               priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
+               break;
+       default:
+               ret = -EINVAL;
+               goto out_free_clock;
+       }
+
+       /* Configure access to registers */
+       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:
+               priv->read_reg = c_can_pci_read_reg_aligned_to_16bit;
+               priv->write_reg = c_can_pci_write_reg_aligned_to_16bit;
+               break;
+       default:
+               ret = -EINVAL;
+               goto out_free_clock;
+       }
+
+       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_dbg(&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:
+       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);
+
+       unregister_c_can_dev(dev);
+
+       if (priv->priv)
+               clk_put(priv->priv);
+
+       pci_set_drvdata(pdev, NULL);
+       free_c_can_dev(dev);
+
+       pci_iounmap(pdev, priv->base);
+       pci_disable_msi(pdev);
+       pci_clear_master(pdev);
+       pci_release_regions(pdev);
+       pci_disable_device(pdev);
+}
+
+static struct c_can_pci_data c_can_sta2x11= {
+       .type = C_CAN_DEVTYPE,
+       .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,     \
+}
+static 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 c_can_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(c_can_pci_driver);
+
+MODULE_AUTHOR("Federico Vaga <federico.vaga@gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("PCI CAN bus driver for Bosch C_CAN/D_CAN controller");
+MODULE_DEVICE_TABLE(pci, c_can_pci_tbl);