|  | /* | 
|  | * 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/mod_devicetable.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\n"); | 
|  | 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; | 
|  |  | 
|  | ptp_dte = devm_kzalloc(dev, sizeof(struct ptp_dte), GFP_KERNEL); | 
|  | if (!ptp_dte) | 
|  | return -ENOMEM; | 
|  |  | 
|  | ptp_dte->regs = devm_platform_ioremap_resource(pdev, 0); | 
|  | if (IS_ERR(ptp_dte->regs)) | 
|  | 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\n", __func__); | 
|  | return PTR_ERR(ptp_dte->ptp_clk); | 
|  | } | 
|  |  | 
|  | platform_set_drvdata(pdev, ptp_dte); | 
|  |  | 
|  | dev_info(dev, "ptp clk probe done\n"); | 
|  |  | 
|  | 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 ptp_dte *ptp_dte = dev_get_drvdata(dev); | 
|  | 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 ptp_dte *ptp_dte = dev_get_drvdata(dev); | 
|  | 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"); |