// SPDX-License-Identifier: GPL-2.0-only /* * CAN bus driver for the Freescale MPC5xxx embedded CPU. * * Copyright (C) 2004-2005 Andrey Volkov , * Varma Electronics Oy * Copyright (C) 2008-2009 Wolfgang Grandegger * Copyright (C) 2009 Wolfram Sang, Pengutronix */ #include #include #include #include #include #include #include #include #include #include #include #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 (!cdm) { of_node_put(np_cdm); dev_err(&ofdev->dev, "can't map clock node!\n"); return 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 : "", 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_put_clock; } err = register_mscandev(dev, mscan_clksrc); if (err) { dev_err(&ofdev->dev, "registering %s failed (err=%d)\n", DRV_NAME, err); goto exit_put_clock; } 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_put_clock: if (data->put_clock) data->put_clock(ofdev); 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 "); MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver"); MODULE_LICENSE("GPL v2");