--- /dev/null
+/*
+ * 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(®s->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");
Code Review / kvmfornfv.git / blobdiff