net/can: add driver for mscan family & mpc52xx_mscan

Taken from socketcan-svn, fixed remaining todos, cleaned up, tested with a
phyCORE-MPC5200B-IO and a custom board.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 279 insertions, 0 deletions

diff --git a/drivers/net/can/mscan/mpc52xx_can.c b/drivers/net/can/mscan/mpc52xx_can.c
new file mode 100644
index 000000000000..4707a82f1ae0
--- /dev/null
+++ b/drivers/net/can/mscan/mpc52xx_can.c
@@ -0,0 +1,279 @@
+/*
+ * CAN bus driver for the Freescale MPC5xxx embedded CPU.
+ *
+ * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>,
+ *                         Varma Electronics Oy
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ * Copyright (C) 2009 Wolfram Sang, Pengutronix <w.sang@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the version 2 of the GNU General Public License
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/netdevice.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/of_platform.h>
+#include <sysdev/fsl_soc.h>
+#include <linux/io.h>
+#include <asm/mpc52xx.h>
+
+#include "mscan.h"
+
+
+#define DRV_NAME "mpc5xxx_can"
+
+static struct of_device_id mpc52xx_cdm_ids[] __devinitdata = {
+        { .compatible = "fsl,mpc5200-cdm", },
+        { .compatible = "fsl,mpc5200b-cdm", },
+        {}
+};
+
+/*
+ * Get the frequency of the external oscillator clock connected
+ * to the SYS_XTAL_IN pin, or return 0 if it cannot be determined.
+ */
+static unsigned int  __devinit mpc52xx_can_xtal_freq(struct of_device *of)
+{
+        struct mpc52xx_cdm  __iomem *cdm;
+        struct device_node *np_cdm;
+        unsigned int freq;
+        u32 val;
+
+        freq = mpc5xxx_get_bus_frequency(of->node);
+        if (!freq)
+                return 0;
+
+        /*
+         * Determine SYS_XTAL_IN frequency from the clock domain settings
+         */
+        np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids);
+        if (!np_cdm) {
+                dev_err(&of->dev, "can't get clock node!\n");
+                return 0;
+        }
+        cdm = of_iomap(np_cdm, 0);
+        of_node_put(np_cdm);
+
+        if (in_8(&cdm->ipb_clk_sel) & 0x1)
+                freq *= 2;
+        val  = in_be32(&cdm->rstcfg);
+        if (val & (1 << 5))
+                freq *= 8;
+        else
+                freq *= 4;
+        if (val & (1 << 6))
+                freq /= 12;
+        else
+                freq /= 16;
+
+        iounmap(cdm);
+
+        return freq;
+}
+
+/*
+ * Get frequency of the MSCAN clock source
+ *
+ * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock (IP_CLK)
+ * can be selected. According to the MPC5200 user's manual, the oscillator
+ * clock is the better choice as it has less jitter but due to a hardware
+ * bug, it can not be selected for the old MPC5200 Rev. A chips.
+ */
+
+static unsigned int  __devinit mpc52xx_can_clock_freq(struct of_device *of,
+                                                      int clock_src)
+{
+        unsigned int pvr;
+
+        pvr = mfspr(SPRN_PVR);
+
+        if (clock_src == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
+                return mpc5xxx_get_bus_frequency(of->node);
+
+        return mpc52xx_can_xtal_freq(of);
+}
+
+static int __devinit mpc5xxx_can_probe(struct of_device *ofdev,
+                                       const struct of_device_id *id)
+{
+        struct device_node *np = ofdev->node;
+        struct net_device *dev;
+        struct mscan_priv *priv;
+        void __iomem *base;
+        const char *clk_src;
+        int err, irq, clock_src;
+
+        base = of_iomap(ofdev->node, 0);
+        if (!base) {
+                dev_err(&ofdev->dev, "couldn't ioremap\n");
+                err = -ENOMEM;
+                goto exit_release_mem;
+        }
+
+        irq = irq_of_parse_and_map(np, 0);
+        if (!irq) {
+                dev_err(&ofdev->dev, "no irq found\n");
+                err = -ENODEV;
+                goto exit_unmap_mem;
+        }
+
+        dev = alloc_mscandev();
+        if (!dev) {
+                err = -ENOMEM;
+                goto exit_dispose_irq;
+        }
+
+        priv = netdev_priv(dev);
+        priv->reg_base = base;
+        dev->irq = irq;
+
+        /*
+         * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock
+         * (IP_CLK) can be selected as MSCAN clock source. According to
+         * the MPC5200 user's manual, the oscillator clock is the better
+         * choice as it has less jitter. For this reason, it is selected
+         * by default.
+         */
+        clk_src = of_get_property(np, "fsl,mscan-clk-src", NULL);
+        if (clk_src && strcmp(clk_src, "ip") == 0)
+                clock_src = MSCAN_CLKSRC_BUS;
+        else
+                clock_src = MSCAN_CLKSRC_XTAL;
+        priv->can.clock.freq = mpc52xx_can_clock_freq(ofdev, clock_src);
+        if (!priv->can.clock.freq) {
+                dev_err(&ofdev->dev, "couldn't get MSCAN clock frequency\n");
+                err = -ENODEV;
+                goto exit_free_mscan;
+        }
+
+        SET_NETDEV_DEV(dev, &ofdev->dev);
+
+        err = register_mscandev(dev, clock_src);
+        if (err) {
+                dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
+                        DRV_NAME, err);
+                goto exit_free_mscan;
+        }
+
+        dev_set_drvdata(&ofdev->dev, dev);
+
+        dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n",
+                 priv->reg_base, dev->irq, priv->can.clock.freq);
+
+        return 0;
+
+exit_free_mscan:
+        free_candev(dev);
+exit_dispose_irq:
+        irq_dispose_mapping(irq);
+exit_unmap_mem:
+        iounmap(base);
+exit_release_mem:
+        return err;
+}
+
+static int __devexit mpc5xxx_can_remove(struct of_device *ofdev)
+{
+        struct net_device *dev = dev_get_drvdata(&ofdev->dev);
+        struct mscan_priv *priv = netdev_priv(dev);
+
+        dev_set_drvdata(&ofdev->dev, NULL);
+
+        unregister_mscandev(dev);
+        iounmap(priv->reg_base);
+        irq_dispose_mapping(dev->irq);
+        free_candev(dev);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static struct mscan_regs saved_regs;
+static int mpc5xxx_can_suspend(struct of_device *ofdev, pm_message_t state)
+{
+        struct net_device *dev = dev_get_drvdata(&ofdev->dev);
+        struct mscan_priv *priv = netdev_priv(dev);
+        struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
+
+        _memcpy_fromio(&saved_regs, regs, sizeof(*regs));
+
+        return 0;
+}
+
+static int mpc5xxx_can_resume(struct of_device *ofdev)
+{
+        struct net_device *dev = dev_get_drvdata(&ofdev->dev);
+        struct mscan_priv *priv = netdev_priv(dev);
+        struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base;
+
+        regs->canctl0 |= MSCAN_INITRQ;
+        while ((regs->canctl1 & MSCAN_INITAK) == 0)
+                udelay(10);
+
+        regs->canctl1 = saved_regs.canctl1;
+        regs->canbtr0 = saved_regs.canbtr0;
+        regs->canbtr1 = saved_regs.canbtr1;
+        regs->canidac = saved_regs.canidac;
+
+        /* restore masks, buffers etc. */
+        _memcpy_toio(&regs->canidar1_0, (void *)&saved_regs.canidar1_0,
+                     sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0));
+
+        regs->canctl0 &= ~MSCAN_INITRQ;
+        regs->cantbsel = saved_regs.cantbsel;
+        regs->canrier = saved_regs.canrier;
+        regs->cantier = saved_regs.cantier;
+        regs->canctl0 = saved_regs.canctl0;
+
+        return 0;
+}
+#endif
+
+static struct of_device_id __devinitdata mpc5xxx_can_table[] = {
+        {.compatible = "fsl,mpc5200-mscan"},
+        {.compatible = "fsl,mpc5200b-mscan"},
+        {},
+};
+
+static struct of_platform_driver mpc5xxx_can_driver = {
+        .owner = THIS_MODULE,
+        .name = "mpc5xxx_can",
+        .probe = mpc5xxx_can_probe,
+        .remove = __devexit_p(mpc5xxx_can_remove),
+#ifdef CONFIG_PM
+        .suspend = mpc5xxx_can_suspend,
+        .resume = mpc5xxx_can_resume,
+#endif
+        .match_table = mpc5xxx_can_table,
+};
+
+static int __init mpc5xxx_can_init(void)
+{
+        return of_register_platform_driver(&mpc5xxx_can_driver);
+}
+module_init(mpc5xxx_can_init);
+
+static void __exit mpc5xxx_can_exit(void)
+{
+        return of_unregister_platform_driver(&mpc5xxx_can_driver);
+};
+module_exit(mpc5xxx_can_exit);
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+MODULE_DESCRIPTION("Freescale MPC5200 CAN driver");
+MODULE_LICENSE("GPL v2");