Date:	Mon,  4 Jun 2012 15:32:46 +0200
From:	Federico Vaga <federico.vaga@...il.com>
To:	Wolfgang Grandegger <wg@...ndegger.com>,
	Marc Kleine-Budde <mkl@...gutronix.de>
Cc:	Federico Vaga <federico.vaga@...il.com>,
	Giancarlo Asnaghi <giancarlo.asnaghi@...com>,
	Alan Cox <alan@...ux.intel.com>,
	Alessandro Rubini <rubini@...dd.com>,
	linux-can@...r.kernel.org, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH RFC] c_can_pci: generic module for c_can on PCI

Signed-off-by: Federico Vaga <federico.vaga@...il.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@...com>
Cc: Alan Cox <alan@...ux.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@...il.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@...il.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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists