diff options
Diffstat (limited to 'drivers/ptp')
| -rw-r--r-- | drivers/ptp/Kconfig | 16 | ||||
| -rw-r--r-- | drivers/ptp/Makefile | 1 | ||||
| -rw-r--r-- | drivers/ptp/ptp_dte.c | 353 |
3 files changed, 370 insertions, 0 deletions
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig index 384f661a6496..a21ad10d613c 100644 --- a/drivers/ptp/Kconfig +++ b/drivers/ptp/Kconfig @@ -25,6 +25,22 @@ config PTP_1588_CLOCK To compile this driver as a module, choose M here: the module will be called ptp. +config PTP_1588_CLOCK_DTE + tristate "Broadcom DTE as PTP clock" + depends on PTP_1588_CLOCK + depends on NET && HAS_IOMEM + depends on ARCH_BCM_MOBILE || (ARCH_BCM_IPROC && !(ARCH_BCM_NSP || ARCH_BCM_5301X)) || COMPILE_TEST + default y + help + This driver adds support for using the Digital timing engine + (DTE) in the Broadcom SoC's as a PTP clock. + + The clock can be used in both wired and wireless networks + for PTP purposes. + + To compile this driver as a module, choose M here: the module + will be called ptp_dte. + config PTP_1588_CLOCK_GIANFAR tristate "Freescale eTSEC as PTP clock" depends on GIANFAR diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile index 530736161a8b..d1f2fb19c980 100644 --- a/drivers/ptp/Makefile +++ b/drivers/ptp/Makefile @@ -4,6 +4,7 @@ ptp-y := ptp_clock.o ptp_chardev.o ptp_sysfs.o obj-$(CONFIG_PTP_1588_CLOCK) += ptp.o +obj-$(CONFIG_PTP_1588_CLOCK_DTE) += ptp_dte.o obj-$(CONFIG_PTP_1588_CLOCK_IXP46X) += ptp_ixp46x.o obj-$(CONFIG_PTP_1588_CLOCK_PCH) += ptp_pch.o obj-$(CONFIG_PTP_1588_CLOCK_KVM) += ptp_kvm.o diff --git a/drivers/ptp/ptp_dte.c b/drivers/ptp/ptp_dte.c new file mode 100644 index 000000000000..00145a3f1e70 --- /dev/null +++ b/drivers/ptp/ptp_dte.c @@ -0,0 +1,353 @@ +/* + * 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 0xFFFFFFFFFFF + +/* 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 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\n", __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\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 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"); |