Re: [net-next PATCH] octeontx2: Add PTP clock driver for Octeon PTM clock.

Sai Krishna Gajula
2024-01-25T10:50:05Z

> -----Original Message-----
> From: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> Sent: Wednesday, January 24, 2024 4:58 PM
> To: Sai Krishna Gajula <saikrishnag@marvell.com>;
> richardcochran@gmail.com; davem@davemloft.net; kuba@kernel.org;
> netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Sunil Kovvuri
> Goutham <sgoutham@marvell.com>; Geethasowjanya Akula
> <gakula@marvell.com>; Linu Cherian <lcherian@marvell.com>; Hariprasad
> Kelam <hkelam@marvell.com>; Subbaraya Sundeep Bhatta
> <sbhatta@marvell.com>
> Cc: Naveen Mamindlapalli <naveenm@marvell.com>
> Subject: Re: [net-next PATCH] octeontx2: Add PTP clock driver for
> Octeon PTM clock.
>
> On 24/01/2024 06:41, Sai Krishna wrote:
> > The PCIe PTM(Precision time measurement) protocol provides precise
> > coordination of events across multiple components like PCIe host
> > clock, PCIe EP PHC local clocks of PCIe devices. This patch adds
> > support for ptp clock based PTM clock. We can use this PTP device to
> > sync the PTM time with CLOCK_REALTIME or other PTP PHC devices using
> > phc2sys.
> >
> > Signed-off-by: Sai Krishna <saikrishnag@marvell.com>
> > Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
> > Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
> > ---
> > drivers/ptp/Kconfig | 10 ++
> > drivers/ptp/Makefile | 1 +
> > drivers/ptp/ptp_octeon_ptm.c | 254
> +++++++++++++++++++++++++++++++++++
> > 3 files changed, 265 insertions(+)
> > create mode 100644 drivers/ptp/ptp_octeon_ptm.c
> >
> > diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig index
> > 5dd5f188e14f..afa82555dbd9 100644
> > --- a/drivers/ptp/Kconfig
> > +++ b/drivers/ptp/Kconfig
> > @@ -212,4 +212,14 @@ config PTP_DFL_TOD
> > To compile this driver as a module, choose M here: the module
> > will be called ptp_dfl_tod.
> >
> > +config PTP_CLOCK_OCTEON
> > + tristate "OCTEON PTM PTP clock"
> > + depends on PTP_1588_CLOCK
> > + default n
> > + help
> > + This driver adds support for using Octeon PTM device clock as
> > + a PTP clock.
> > +
> > + To compile this driver as a module, choose M here: the module
> > + will be called ptp_octeon_ptm.
> > endmenu
> > diff --git a/drivers/ptp/Makefile b/drivers/ptp/Makefile index
> > dea0cebd2303..e811ae6df5c0 100644
> > --- a/drivers/ptp/Makefile
> > +++ b/drivers/ptp/Makefile
> > @@ -20,3 +20,4 @@ obj-$(CONFIG_PTP_1588_CLOCK_MOCK) +=
> ptp_mock.o
> > obj-$(CONFIG_PTP_1588_CLOCK_VMW) += ptp_vmw.o
> > obj-$(CONFIG_PTP_1588_CLOCK_OCP) += ptp_ocp.o
> > obj-$(CONFIG_PTP_DFL_TOD) += ptp_dfl_tod.o
> > +obj-$(CONFIG_PTP_CLOCK_OCTEON) +=
> ptp_octeon_ptm.o
> > diff --git a/drivers/ptp/ptp_octeon_ptm.c
> > b/drivers/ptp/ptp_octeon_ptm.c new file mode 100644 index
> > 000000000000..da069645ebf7
> > --- /dev/null
> > +++ b/drivers/ptp/ptp_octeon_ptm.c
> > @@ -0,0 +1,254 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Marvell PTP PHC clock driver for PCIe PTM (Precision Time
> > +Measurement) EP
> > + *
> > + * Copyright (c) 2023 Marvell.
> > + *
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/device.h>
> > +#include <linux/err.h>
> > +#include <linux/init.h>
> > +#include <linux/kernel.h>
> > +#include <linux/pci.h>
> > +#include <linux/slab.h>
> > +#include <linux/module.h>
> > +
> > +#include <linux/ptp_clock_kernel.h>
> > +
> > +#include "ptp_private.h"
> > +
> > +#define PEMX_PFX_CSX_PFCFGX(pem, pf, _offset) ({typeof(_offset)
> (offset) = (_offset); \
> > + ((0x8e0000008000 |
> (u64)(pem) << 36 \
> > + | (pf) << 18 \
> > + | (((offset) >> 16) & 1) << 16 \
> > + | ((offset) >> 3) << 3) \
> > + + ((((offset) >> 2) & 1) << 2));
> })
> > +
> > +#define PEMX_CFG_WR(a) (0x8E0000000018ull | (u64)(a)
> << 36)
> > +#define PEMX_CFG_RD(a) (0x8E0000000020ull | (u64)(a)
> << 36)
> > +
> > +/* Octeon CSRs */
> > +#define PEMX_CFG 0x8e00000000d8ULL
> > +#define PEMX_PTM_CTL 0x8e0000000098ULL
> > +#define PEMX_PTM_CTL_CAP BIT_ULL(10)
> > +#define PEMX_PTM_LCL_TIME 0x8e00000000a0ULL /* PTM
> time */
> > +#define PEMX_PTM_MAS_TIME 0x8e00000000a8ULL /* PTP
> time */
> > +#define PTM_DEBUG 0
> > +
> > +struct oct_ptp_clock {
> > + struct ptp_clock *ptp_clock;
> > + struct ptp_clock_info caps;
> > + bool cn10k_variant;
> > +};
> > +
> > +static struct oct_ptp_clock oct_ptp_clock; static void __iomem
> > +*ptm_ctl_addr; static void __iomem *ptm_lcl_addr;
> > +
> > +/* Config space registers */
> > +#define PCIEEPX_PTM_REQ_STAT (oct_ptp_clock.cn10k_variant
> ? 0x3a8 : 0x474)
> > +#define PCIEEPX_PTM_REQ_T1L (oct_ptp_clock.cn10k_variant
> ? 0x3b4 : 0x480)
> > +#define PCIEEPX_PTM_REQ_T1M (oct_ptp_clock.cn10k_variant
> ? 0x3b8 : 0x484)
> > +#define PCIEEPX_PTM_REQ_T4L (oct_ptp_clock.cn10k_variant
> ? 0x3c4 : 0x490)
> > +#define PCIEEPX_PTM_REQ_T4M (oct_ptp_clock.cn10k_variant
> ? 0x3c8 : 0x494)
> > +
> > +#define PCI_VENDOR_ID_CAVIUM 0x177d
> > +#define PCI_DEVID_OCTEONTX2_PTP 0xA00C
> > +#define PCI_SUBSYS_DEVID_95XX 0xB300
> > +#define PCI_SUBSYS_DEVID_95XXN 0xB400
> > +#define PCI_SUBSYS_DEVID_95XXMM 0xB500
> > +#define PCI_SUBSYS_DEVID_96XX 0xB200
> > +#define PCI_SUBSYS_DEVID_98XX 0xB100
> > +#define PCI_SUBSYS_DEVID_CN10K_A 0xB900
> > +#define PCI_SUBSYS_DEVID_CN10K_B 0xBD00
> > +#define PCI_SUBSYS_DEVID_CNF10K_A 0xBA00
> > +#define PCI_SUBSYS_DEVID_CNF10K_B 0xBC00
> > +
> > +static bool is_otx2_support_ptm(struct pci_dev *pdev) {
> > + return (pdev->subsystem_device == PCI_SUBSYS_DEVID_96XX ||
> > + pdev->subsystem_device == PCI_SUBSYS_DEVID_95XX ||
> > + pdev->subsystem_device == PCI_SUBSYS_DEVID_95XXN ||
> > + pdev->subsystem_device == PCI_SUBSYS_DEVID_98XX ||
> > + pdev->subsystem_device == PCI_SUBSYS_DEVID_95XXMM);
> }
> > +
> > +static bool is_cn10k_support_ptm(struct pci_dev *pdev) {
> > + return (pdev->subsystem_device == PCI_SUBSYS_DEVID_CN10K_A
> ||
> > + pdev->subsystem_device == PCI_SUBSYS_DEVID_CNF10K_A
> ||
> > + pdev->subsystem_device == PCI_SUBSYS_DEVID_CN10K_B
> ||
> > + pdev->subsystem_device ==
> PCI_SUBSYS_DEVID_CNF10K_B); }
> > +
> > +static int ptp_oct_ptm_adjtime(struct ptp_clock_info *ptp, s64 delta)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static int ptp_oct_ptm_settime(struct ptp_clock_info *ptp,
> > + const struct timespec64 *ts) {
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static u32 read_pcie_config32(int ep_pem, int cfg_addr) {
> > + void __iomem *addr;
> > + u64 val;
> > +
> > + if (oct_ptp_clock.cn10k_variant) {
> > + addr = ioremap(PEMX_PFX_CSX_PFCFGX(ep_pem, 0,
> cfg_addr), 8);
> > + if (!addr) {
> > + pr_err("PTM_EP: Failed to ioremap Octeon CSR
> space\n");
> > + return -1U;
> > + }
> > + val = readl(addr);
> > + iounmap(addr);
> > + } else {
> > + addr = ioremap(PEMX_CFG_RD(ep_pem), 8);
> > + if (!addr) {
> > + pr_err("PTM_EP: Failed to ioremap Octeon CSR
> space\n");
> > + return -1U;
> > + }
> > + val = ((1 << 15) | (cfg_addr & 0xfff));
> > + writeq(val, addr);
> > + val = readq(addr) >> 32;
> > + iounmap(addr);
> > + }
> > + return (val & 0xffffffff);
> > +}
> > +
> > +static uint64_t octeon_csr_read(u64 csr_addr) {
> > + u64 val;
> > + void __iomem *addr;
> > +
> > + addr = ioremap(csr_addr, 8);
> > + if (!addr) {
> > + pr_err("PTM_EP: Failed to ioremap CSR space\n");
> > + return -1UL;
> > + }
> > + val = (u64)READ_ONCE(*(u64 __iomem *)addr);
> > + iounmap(addr);
> > + return val;
> > +}
> > +
> > +static int ptp_oct_ptm_gettime(struct ptp_clock_info *ptp, struct
> > +timespec64 *ts) {
> > + u64 ptp_time, val64;
> > +#if PTM_DEBUG
> > + u64 ptm_time;
> > +#endif
>
> Looks like some out-of-tree debug artifacts here and later in the function

Ack, will remove the debug code in V2 patch.

>
> > + u32 val32;
> > +
> > + /* Check for valid PTM context */
> > + val32 = read_pcie_config32(0, PCIEEPX_PTM_REQ_STAT);
> > + if (!(val32 & 0x1)) {
> > + pr_err("PTM_EP: ERROR: PTM context not valid: 0x%x\n",
> val32); #if
> > +PTM_DEBUG
> > + ptm_time = 0;
> > +#endif
> > + ptp_time = 0;
>
> No reason to clean up local variables.

Ack, will submit V2 patch

>
> > + ts->tv_sec = 0;
> > + ts->tv_nsec = 0;
> > +
> > + return -EINVAL;
> > + }
> > +
> > + /* Trigger PTM/PTP capture */
> > + val64 = (u64)READ_ONCE(*(u64 __iomem *)ptm_ctl_addr);
> > + val64 |= PEMX_PTM_CTL_CAP;
> > + WRITE_ONCE(*(u64 __iomem *)ptm_ctl_addr, val64);
> > + /* Read PTM/PTP clocks */
> > + ptp_time = (u64)READ_ONCE(*(u64 __iomem *)ptm_lcl_addr);
> > + ts->tv_sec = ptp_time / NSEC_PER_SEC;
> > + ts->tv_nsec = ptp_time % NSEC_PER_SEC;
>
> ns_to_timespec64() here?

Ack, thanks for pointing out, will use this and submit in V2 patch.

>
> > +
> > +#if PTM_DEBUG
> > + ptm_time = octeon_csr_read(PEMX_PTM_MAS_TIME);
> > + pr_info("PTM_EP: system %lld ptm time: %lld\n", ptp_time,
> ptm_time);
> > +#endif
> > +
> > + return 0;
> > +}
> > +
> > +static int ptp_oct_ptm_enable(struct ptp_clock_info *ptp,
> > + struct ptp_clock_request *rq, int on) {
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static const struct ptp_clock_info ptp_oct_caps = {
> > + .owner = THIS_MODULE,
> > + .name = "OCTEON PTM PHC",
> > + .max_adj = 0,
> > + .n_ext_ts = 0,
> > + .n_pins = 0,
> > + .pps = 0,
> > + .adjtime = ptp_oct_ptm_adjtime,
> > + .gettime64 = ptp_oct_ptm_gettime,
> > + .settime64 = ptp_oct_ptm_settime,
> > + .enable = ptp_oct_ptm_enable,
> > +};
> > +
> > +static void __exit ptp_oct_ptm_exit(void) {
> > + iounmap(ptm_ctl_addr);
> > + iounmap(ptm_lcl_addr);
> > + ptp_clock_unregister(oct_ptp_clock.ptp_clock);
> > +}
> > +
> > +static int __init ptp_oct_ptm_init(void) {
> > + struct pci_dev *pdev = NULL;
> > +
> > + pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM,
> > + PCI_DEVID_OCTEONTX2_PTP, pdev);
> > + if (!pdev)
> > + return 0;
> > +
> > + if (octeon_csr_read(PEMX_CFG) & 0x1ULL) {
> > + pr_err("PEM0 is configured as RC\n");
> > + return 0;
> > + }
> > +
> > + if (is_otx2_support_ptm(pdev)) {
> > + oct_ptp_clock.cn10k_variant = 0;
> > + } else if (is_cn10k_support_ptm(pdev)) {
> > + oct_ptp_clock.cn10k_variant = 1;
> > + } else {
> > + /* PTM_EP: unsupported processor */
> > + return 0;
> > + }
> > +
> > + ptm_ctl_addr = ioremap(PEMX_PTM_CTL, 8);
> > + if (!ptm_ctl_addr) {
> > + pr_err("PTM_EP: Failed to ioremap CSR space\n");
> > + return 0;
> > + }
> > +
> > + ptm_lcl_addr = ioremap(PEMX_PTM_LCL_TIME, 8);
> > + if (!ptm_lcl_addr) {
> > + pr_err("PTM_EP: Failed to ioremap CSR space\n");
> > + return 0;
> > + }
> > +
> > + oct_ptp_clock.caps = ptp_oct_caps;
> > +
> > + oct_ptp_clock.ptp_clock = ptp_clock_register(&oct_ptp_clock.caps,
> > +NULL);
> > +
> > + pr_info("PTP device index for PTM clock:%d\n",
> oct_ptp_clock.ptp_clock->index);
> > + pr_info("cn10k_variant %d\n", oct_ptp_clock.cn10k_variant);
> > +
> > + return PTR_ERR_OR_ZERO(oct_ptp_clock.ptp_clock);
> > +}
> > +
> > +module_init(ptp_oct_ptm_init);
> > +module_exit(ptp_oct_ptm_exit);
> > +
> > +MODULE_AUTHOR("Marvell Inc.");
> > +MODULE_DESCRIPTION("PTP PHC clock using PTM");
> MODULE_LICENSE("GPL");