1 files changed, 458 insertions, 0 deletions
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
new file mode 100644
index 000000000..c7427bdd3
--- /dev/null
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -0,0 +1,458 @@
+/*
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/netdevice.h>
+#include <linux/can/dev.h>
+#include <linux/of_platform.h>
+#include <sysdev/fsl_soc.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <asm/mpc52xx.h>
+
+#include "mscan.h"
+
+#define DRV_NAME "mpc5xxx_can"
+
+struct mpc5xxx_can_data {
+	unsigned int type;
+	u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name,
+			 int *mscan_clksrc);
+	void (*put_clock)(struct platform_device *ofdev);
+};
+
+#ifdef CONFIG_PPC_MPC52xx
+static const struct of_device_id mpc52xx_cdm_ids[] = {
+	{ .compatible = "fsl,mpc5200-cdm", },
+	{}
+};
+
+static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
+				 const char *clock_name, int *mscan_clksrc)
+{
+	unsigned int pvr;
+	struct mpc52xx_cdm  __iomem *cdm;
+	struct device_node *np_cdm;
+	unsigned int freq;
+	u32 val;
+
+	pvr = mfspr(SPRN_PVR);
+
+	/*
+	 * 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. Unfortunately, it can not be selected for the old
+	 * MPC5200 Rev. A chips due to a hardware bug (check errata).
+	 */
+	if (clock_name && strcmp(clock_name, "ip") == 0)
+		*mscan_clksrc = MSCAN_CLKSRC_BUS;
+	else
+		*mscan_clksrc = MSCAN_CLKSRC_XTAL;
+
+	freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
+	if (!freq)
+		return 0;
+
+	if (*mscan_clksrc == MSCAN_CLKSRC_BUS || pvr == 0x80822011)
+		return freq;
+
+	/* 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(&ofdev->dev, "can't get clock node!\n");
+		return 0;
+	}
+	cdm = of_iomap(np_cdm, 0);
+
+	if (in_8(&cdm->ipb_clk_sel) & 0x1)
+		freq *= 2;
+	val = in_be32(&cdm->rstcfg);
+
+	freq *= (val & (1 << 5)) ? 8 : 4;
+	freq /= (val & (1 << 6)) ? 12 : 16;
+
+	of_node_put(np_cdm);
+	iounmap(cdm);
+
+	return freq;
+}
+#else /* !CONFIG_PPC_MPC52xx */
+static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
+				 const char *clock_name, int *mscan_clksrc)
+{
+	return 0;
+}
+#endif /* CONFIG_PPC_MPC52xx */
+
+#ifdef CONFIG_PPC_MPC512x
+static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
+				 const char *clock_source, int *mscan_clksrc)
+{
+	struct device_node *np;
+	u32 clockdiv;
+	enum {
+		CLK_FROM_AUTO,
+		CLK_FROM_IPS,
+		CLK_FROM_SYS,
+		CLK_FROM_REF,
+	} clk_from;
+	struct clk *clk_in, *clk_can;
+	unsigned long freq_calc;
+	struct mscan_priv *priv;
+	struct clk *clk_ipg;
+
+	/* the caller passed in the clock source spec that was read from
+	 * the device tree, get the optional clock divider as well
+	 */
+	np = ofdev->dev.of_node;
+	clockdiv = 1;
+	of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv);
+	dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n",
+		clock_source ? clock_source : "<NULL>", clockdiv);
+
+	/* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to
+	 * get set, and the 'ips' clock is the input to the MSCAN
+	 * component
+	 *
+	 * for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC]
+	 * bit needs to get cleared, an optional clock-divider may have
+	 * been specified (the default value is 1), the appropriate
+	 * MSCAN related MCLK is the input to the MSCAN component
+	 *
+	 * in the absence of a clock-source spec, first an optimal clock
+	 * gets determined based on the 'sys' clock, if that fails the
+	 * 'ref' clock is used
+	 */
+	clk_from = CLK_FROM_AUTO;
+	if (clock_source) {
+		/* interpret the device tree's spec for the clock source */
+		if (!strcmp(clock_source, "ip"))
+			clk_from = CLK_FROM_IPS;
+		else if (!strcmp(clock_source, "sys"))
+			clk_from = CLK_FROM_SYS;
+		else if (!strcmp(clock_source, "ref"))
+			clk_from = CLK_FROM_REF;
+		else
+			goto err_invalid;
+		dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from);
+	}
+	if (clk_from == CLK_FROM_AUTO) {
+		/* no spec so far, try the 'sys' clock; round to the
+		 * next MHz and see if we can get a multiple of 16MHz
+		 */
+		dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n");
+		clk_in = devm_clk_get(&ofdev->dev, "sys");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		freq_calc = clk_get_rate(clk_in);
+		freq_calc +=  499999;
+		freq_calc /= 1000000;
+		freq_calc *= 1000000;
+		if ((freq_calc % 16000000) == 0) {
+			clk_from = CLK_FROM_SYS;
+			clockdiv = freq_calc / 16000000;
+			dev_dbg(&ofdev->dev,
+				"clk fit, sys[%lu] div[%d] freq[%lu]\n",
+				freq_calc, clockdiv, freq_calc / clockdiv);
+		}
+	}
+	if (clk_from == CLK_FROM_AUTO) {
+		/* no spec so far, use the 'ref' clock */
+		dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n");
+		clk_in = devm_clk_get(&ofdev->dev, "ref");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		clk_from = CLK_FROM_REF;
+		freq_calc = clk_get_rate(clk_in);
+		dev_dbg(&ofdev->dev,
+			"clk fit, ref[%lu] (no div) freq[%lu]\n",
+			freq_calc, freq_calc);
+	}
+
+	/* select IPS or MCLK as the MSCAN input (returned to the caller),
+	 * setup the MCLK mux source and rate if applicable, apply the
+	 * optionally specified or derived above divider, and determine
+	 * the actual resulting clock rate to return to the caller
+	 */
+	switch (clk_from) {
+	case CLK_FROM_IPS:
+		clk_can = devm_clk_get(&ofdev->dev, "ips");
+		if (IS_ERR(clk_can))
+			goto err_notavail;
+		priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+		priv->clk_can = clk_can;
+		freq_calc = clk_get_rate(clk_can);
+		*mscan_clksrc = MSCAN_CLKSRC_IPS;
+		dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n",
+			*mscan_clksrc, freq_calc);
+		break;
+	case CLK_FROM_SYS:
+	case CLK_FROM_REF:
+		clk_can = devm_clk_get(&ofdev->dev, "mclk");
+		if (IS_ERR(clk_can))
+			goto err_notavail;
+		priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+		priv->clk_can = clk_can;
+		if (clk_from == CLK_FROM_SYS)
+			clk_in = devm_clk_get(&ofdev->dev, "sys");
+		if (clk_from == CLK_FROM_REF)
+			clk_in = devm_clk_get(&ofdev->dev, "ref");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		clk_set_parent(clk_can, clk_in);
+		freq_calc = clk_get_rate(clk_in);
+		freq_calc /= clockdiv;
+		clk_set_rate(clk_can, freq_calc);
+		freq_calc = clk_get_rate(clk_can);
+		*mscan_clksrc = MSCAN_CLKSRC_BUS;
+		dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n",
+			*mscan_clksrc, freq_calc);
+		break;
+	default:
+		goto err_invalid;
+	}
+
+	/* the above clk_can item is used for the bitrate, access to
+	 * the peripheral's register set needs the clk_ipg item
+	 */
+	clk_ipg = devm_clk_get(&ofdev->dev, "ipg");
+	if (IS_ERR(clk_ipg))
+		goto err_notavail_ipg;
+	if (clk_prepare_enable(clk_ipg))
+		goto err_notavail_ipg;
+	priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+	priv->clk_ipg = clk_ipg;
+
+	/* return the determined clock source rate */
+	return freq_calc;
+
+err_invalid:
+	dev_err(&ofdev->dev, "invalid clock source specification\n");
+	/* clock source rate could not get determined */
+	return 0;
+
+err_notavail:
+	dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n");
+	/* clock source rate could not get determined */
+	return 0;
+
+err_notavail_ipg:
+	dev_err(&ofdev->dev, "cannot acquire or setup register clock\n");
+	/* clock source rate could not get determined */
+	return 0;
+}
+
+static void mpc512x_can_put_clock(struct platform_device *ofdev)
+{
+	struct mscan_priv *priv;
+
+	priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+	if (priv->clk_ipg)
+		clk_disable_unprepare(priv->clk_ipg);
+}
+#else /* !CONFIG_PPC_MPC512x */
+static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
+				 const char *clock_name, int *mscan_clksrc)
+{
+	return 0;
+}
+#define mpc512x_can_put_clock NULL
+#endif /* CONFIG_PPC_MPC512x */
+
+static const struct of_device_id mpc5xxx_can_table[];
+static int mpc5xxx_can_probe(struct platform_device *ofdev)
+{
+	const struct of_device_id *match;
+	const struct mpc5xxx_can_data *data;
+	struct device_node *np = ofdev->dev.of_node;
+	struct net_device *dev;
+	struct mscan_priv *priv;
+	void __iomem *base;
+	const char *clock_name = NULL;
+	int irq, mscan_clksrc = 0;
+	int err = -ENOMEM;
+
+	match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
+	if (!match)
+		return -EINVAL;
+	data = match->data;
+
+	base = of_iomap(np, 0);
+	if (!base) {
+		dev_err(&ofdev->dev, "couldn't ioremap\n");
+		return err;
+	}
+
+	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)
+		goto exit_dispose_irq;
+	platform_set_drvdata(ofdev, dev);
+	SET_NETDEV_DEV(dev, &ofdev->dev);
+
+	priv = netdev_priv(dev);
+	priv->reg_base = base;
+	dev->irq = irq;
+
+	clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL);
+
+	BUG_ON(!data);
+	priv->type = data->type;
+	priv->can.clock.freq = data->get_clock(ofdev, clock_name,
+					       &mscan_clksrc);
+	if (!priv->can.clock.freq) {
+		dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n");
+		goto exit_free_mscan;
+	}
+
+	err = register_mscandev(dev, mscan_clksrc);
+	if (err) {
+		dev_err(&ofdev->dev, "registering %s failed (err=%d)\n",
+			DRV_NAME, err);
+		goto exit_free_mscan;
+	}
+
+	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);
+
+	return err;
+}
+
+static int mpc5xxx_can_remove(struct platform_device *ofdev)
+{
+	const struct of_device_id *match;
+	const struct mpc5xxx_can_data *data;
+	struct net_device *dev = platform_get_drvdata(ofdev);
+	struct mscan_priv *priv = netdev_priv(dev);
+
+	match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
+	data = match ? match->data : NULL;
+
+	unregister_mscandev(dev);
+	if (data && data->put_clock)
+		data->put_clock(ofdev);
+	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 platform_device *ofdev, pm_message_t state)
+{
+	struct net_device *dev = platform_get_drvdata(ofdev);
+	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 platform_device *ofdev)
+{
+	struct net_device *dev = platform_get_drvdata(ofdev);
+	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))
+		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 const struct mpc5xxx_can_data mpc5200_can_data = {
+	.type = MSCAN_TYPE_MPC5200,
+	.get_clock = mpc52xx_can_get_clock,
+	/* .put_clock not applicable */
+};
+
+static const struct mpc5xxx_can_data mpc5121_can_data = {
+	.type = MSCAN_TYPE_MPC5121,
+	.get_clock = mpc512x_can_get_clock,
+	.put_clock = mpc512x_can_put_clock,
+};
+
+static const struct of_device_id mpc5xxx_can_table[] = {
+	{ .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, },
+	/* Note that only MPC5121 Rev. 2 (and later) is supported */
+	{ .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mpc5xxx_can_table);
+
+static struct platform_driver mpc5xxx_can_driver = {
+	.driver = {
+		.name = "mpc5xxx_can",
+		.of_match_table = mpc5xxx_can_table,
+	},
+	.probe = mpc5xxx_can_probe,
+	.remove = mpc5xxx_can_remove,
+#ifdef CONFIG_PM
+	.suspend = mpc5xxx_can_suspend,
+	.resume = mpc5xxx_can_resume,
+#endif
+};
+
+module_platform_driver(mpc5xxx_can_driver);
+
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver");
+MODULE_LICENSE("GPL v2");