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drivers/ptp/ptp_dte.c
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81f7e3824 Initial Release, ... |
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/* * Copyright 2017 Broadcom * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation version 2. * * This program is distributed "as is" WITHOUT ANY WARRANTY of any * kind, whether express or implied; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <linux/err.h> #include <linux/io.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/ptp_clock_kernel.h> #include <linux/types.h> #define DTE_NCO_LOW_TIME_REG 0x00 #define DTE_NCO_TIME_REG 0x04 #define DTE_NCO_OVERFLOW_REG 0x08 #define DTE_NCO_INC_REG 0x0c #define DTE_NCO_SUM2_MASK 0xffffffff #define DTE_NCO_SUM2_SHIFT 4ULL #define DTE_NCO_SUM3_MASK 0xff #define DTE_NCO_SUM3_SHIFT 36ULL #define DTE_NCO_SUM3_WR_SHIFT 8 #define DTE_NCO_TS_WRAP_MASK 0xfff #define DTE_NCO_TS_WRAP_LSHIFT 32 #define DTE_NCO_INC_DEFAULT 0x80000000 #define DTE_NUM_REGS_TO_RESTORE 4 /* Full wrap around is 44bits in ns (~4.887 hrs) */ #define DTE_WRAP_AROUND_NSEC_SHIFT 44 /* 44 bits NCO */ #define DTE_NCO_MAX_NS 0xFFFFFFFFFFFLL /* 125MHz with 3.29 reg cfg */ #define DTE_PPB_ADJ(ppb) (u32)(div64_u64((((u64)abs(ppb) * BIT(28)) +\ 62500000ULL), 125000000ULL)) /* ptp dte priv structure */ struct ptp_dte { void __iomem *regs; struct ptp_clock *ptp_clk; struct ptp_clock_info caps; struct device *dev; u32 ts_ovf_last; u32 ts_wrap_cnt; spinlock_t lock; u32 reg_val[DTE_NUM_REGS_TO_RESTORE]; }; static void dte_write_nco(void __iomem *regs, s64 ns) { u32 sum2, sum3; sum2 = (u32)((ns >> DTE_NCO_SUM2_SHIFT) & DTE_NCO_SUM2_MASK); /* compensate for ignoring sum1 */ if (sum2 != DTE_NCO_SUM2_MASK) sum2++; /* to write sum3, bits [15:8] needs to be written */ sum3 = (u32)(((ns >> DTE_NCO_SUM3_SHIFT) & DTE_NCO_SUM3_MASK) << DTE_NCO_SUM3_WR_SHIFT); writel(0, (regs + DTE_NCO_LOW_TIME_REG)); writel(sum2, (regs + DTE_NCO_TIME_REG)); writel(sum3, (regs + DTE_NCO_OVERFLOW_REG)); } static s64 dte_read_nco(void __iomem *regs) { u32 sum2, sum3; s64 ns; /* * ignoring sum1 (4 bits) gives a 16ns resolution, which * works due to the async register read. */ sum3 = readl(regs + DTE_NCO_OVERFLOW_REG) & DTE_NCO_SUM3_MASK; sum2 = readl(regs + DTE_NCO_TIME_REG); ns = ((s64)sum3 << DTE_NCO_SUM3_SHIFT) | ((s64)sum2 << DTE_NCO_SUM2_SHIFT); return ns; } static void dte_write_nco_delta(struct ptp_dte *ptp_dte, s64 delta) { s64 ns; ns = dte_read_nco(ptp_dte->regs); /* handle wraparound conditions */ if ((delta < 0) && (abs(delta) > ns)) { if (ptp_dte->ts_wrap_cnt) { ns += DTE_NCO_MAX_NS + delta; ptp_dte->ts_wrap_cnt--; } else { ns = 0; } } else { ns += delta; if (ns > DTE_NCO_MAX_NS) { ptp_dte->ts_wrap_cnt++; ns -= DTE_NCO_MAX_NS; } } dte_write_nco(ptp_dte->regs, ns); ptp_dte->ts_ovf_last = (ns >> DTE_NCO_TS_WRAP_LSHIFT) & DTE_NCO_TS_WRAP_MASK; } static s64 dte_read_nco_with_ovf(struct ptp_dte *ptp_dte) { u32 ts_ovf; s64 ns = 0; ns = dte_read_nco(ptp_dte->regs); /*Timestamp overflow: 8 LSB bits of sum3, 4 MSB bits of sum2 */ ts_ovf = (ns >> DTE_NCO_TS_WRAP_LSHIFT) & DTE_NCO_TS_WRAP_MASK; /* Check for wrap around */ if (ts_ovf < ptp_dte->ts_ovf_last) ptp_dte->ts_wrap_cnt++; ptp_dte->ts_ovf_last = ts_ovf; /* adjust for wraparounds */ ns += (s64)(BIT_ULL(DTE_WRAP_AROUND_NSEC_SHIFT) * ptp_dte->ts_wrap_cnt); return ns; } static int ptp_dte_adjfreq(struct ptp_clock_info *ptp, s32 ppb) { u32 nco_incr; unsigned long flags; struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); if (abs(ppb) > ptp_dte->caps.max_adj) { dev_err(ptp_dte->dev, "ppb adj too big "); return -EINVAL; } if (ppb < 0) nco_incr = DTE_NCO_INC_DEFAULT - DTE_PPB_ADJ(ppb); else nco_incr = DTE_NCO_INC_DEFAULT + DTE_PPB_ADJ(ppb); spin_lock_irqsave(&ptp_dte->lock, flags); writel(nco_incr, ptp_dte->regs + DTE_NCO_INC_REG); spin_unlock_irqrestore(&ptp_dte->lock, flags); return 0; } static int ptp_dte_adjtime(struct ptp_clock_info *ptp, s64 delta) { unsigned long flags; struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); spin_lock_irqsave(&ptp_dte->lock, flags); dte_write_nco_delta(ptp_dte, delta); spin_unlock_irqrestore(&ptp_dte->lock, flags); return 0; } static int ptp_dte_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) { unsigned long flags; struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); spin_lock_irqsave(&ptp_dte->lock, flags); *ts = ns_to_timespec64(dte_read_nco_with_ovf(ptp_dte)); spin_unlock_irqrestore(&ptp_dte->lock, flags); return 0; } static int ptp_dte_settime(struct ptp_clock_info *ptp, const struct timespec64 *ts) { unsigned long flags; struct ptp_dte *ptp_dte = container_of(ptp, struct ptp_dte, caps); spin_lock_irqsave(&ptp_dte->lock, flags); /* Disable nco increment */ writel(0, ptp_dte->regs + DTE_NCO_INC_REG); dte_write_nco(ptp_dte->regs, timespec64_to_ns(ts)); /* reset overflow and wrap counter */ ptp_dte->ts_ovf_last = 0; ptp_dte->ts_wrap_cnt = 0; /* Enable nco increment */ writel(DTE_NCO_INC_DEFAULT, ptp_dte->regs + DTE_NCO_INC_REG); spin_unlock_irqrestore(&ptp_dte->lock, flags); return 0; } static int ptp_dte_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *rq, int on) { return -EOPNOTSUPP; } static const struct ptp_clock_info ptp_dte_caps = { .owner = THIS_MODULE, .name = "DTE PTP timer", .max_adj = 50000000, .n_ext_ts = 0, .n_pins = 0, .pps = 0, .adjfreq = ptp_dte_adjfreq, .adjtime = ptp_dte_adjtime, .gettime64 = ptp_dte_gettime, .settime64 = ptp_dte_settime, .enable = ptp_dte_enable, }; static int ptp_dte_probe(struct platform_device *pdev) { struct ptp_dte *ptp_dte; struct device *dev = &pdev->dev; struct resource *res; ptp_dte = devm_kzalloc(dev, sizeof(struct ptp_dte), GFP_KERNEL); if (!ptp_dte) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); ptp_dte->regs = devm_ioremap_resource(dev, res); if (IS_ERR(ptp_dte->regs)) { dev_err(dev, "%s: io remap failed ", __func__); return PTR_ERR(ptp_dte->regs); } spin_lock_init(&ptp_dte->lock); ptp_dte->dev = dev; ptp_dte->caps = ptp_dte_caps; ptp_dte->ptp_clk = ptp_clock_register(&ptp_dte->caps, &pdev->dev); if (IS_ERR(ptp_dte->ptp_clk)) { dev_err(dev, "%s: Failed to register ptp clock ", __func__); return PTR_ERR(ptp_dte->ptp_clk); } platform_set_drvdata(pdev, ptp_dte); dev_info(dev, "ptp clk probe done "); return 0; } static int ptp_dte_remove(struct platform_device *pdev) { struct ptp_dte *ptp_dte = platform_get_drvdata(pdev); u8 i; ptp_clock_unregister(ptp_dte->ptp_clk); for (i = 0; i < DTE_NUM_REGS_TO_RESTORE; i++) writel(0, ptp_dte->regs + (i * sizeof(u32))); return 0; } #ifdef CONFIG_PM_SLEEP static int ptp_dte_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct ptp_dte *ptp_dte = platform_get_drvdata(pdev); u8 i; for (i = 0; i < DTE_NUM_REGS_TO_RESTORE; i++) { ptp_dte->reg_val[i] = readl(ptp_dte->regs + (i * sizeof(u32))); } /* disable the nco */ writel(0, ptp_dte->regs + DTE_NCO_INC_REG); return 0; } static int ptp_dte_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct ptp_dte *ptp_dte = platform_get_drvdata(pdev); u8 i; for (i = 0; i < DTE_NUM_REGS_TO_RESTORE; i++) { if ((i * sizeof(u32)) != DTE_NCO_OVERFLOW_REG) writel(ptp_dte->reg_val[i], (ptp_dte->regs + (i * sizeof(u32)))); else writel(((ptp_dte->reg_val[i] & DTE_NCO_SUM3_MASK) << DTE_NCO_SUM3_WR_SHIFT), (ptp_dte->regs + (i * sizeof(u32)))); } return 0; } static const struct dev_pm_ops ptp_dte_pm_ops = { .suspend = ptp_dte_suspend, .resume = ptp_dte_resume }; #define PTP_DTE_PM_OPS (&ptp_dte_pm_ops) #else #define PTP_DTE_PM_OPS NULL #endif static const struct of_device_id ptp_dte_of_match[] = { { .compatible = "brcm,ptp-dte", }, {}, }; MODULE_DEVICE_TABLE(of, ptp_dte_of_match); static struct platform_driver ptp_dte_driver = { .driver = { .name = "ptp-dte", .pm = PTP_DTE_PM_OPS, .of_match_table = ptp_dte_of_match, }, .probe = ptp_dte_probe, .remove = ptp_dte_remove, }; module_platform_driver(ptp_dte_driver); MODULE_AUTHOR("Broadcom"); MODULE_DESCRIPTION("Broadcom DTE PTP Clock driver"); MODULE_LICENSE("GPL v2"); |