This patch adds a pair of new ioctls to the PTP Hardware Clock device interface. Using the ioctls, user space programs can query each pin to find out its current function and also reprogram a different function if desired.
Signed-off-by: Richard Cochran <richardcoch...@gmail.com> --- drivers/ptp/ptp_chardev.c | 133 +++++++++++++++++++++++++++++++++++++- drivers/ptp/ptp_clock.c | 23 +++++++ drivers/ptp/ptp_private.h | 4 ++ include/linux/ptp_clock_kernel.h | 33 ++++++++++ include/uapi/linux/ptp_clock.h | 39 ++++++++++- 5 files changed, 230 insertions(+), 2 deletions(-) diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c index 34a0c60..bcbc930 100644 --- a/drivers/ptp/ptp_chardev.c +++ b/drivers/ptp/ptp_chardev.c @@ -25,6 +25,104 @@ #include "ptp_private.h" +static int ptp_disable_pinfunc(struct ptp_clock_info *ops, + enum ptp_pin_function func, unsigned int chan) +{ + struct ptp_clock_request rq; + int err = 0; + + memset(&rq, 0, sizeof(rq)); + + switch (func) { + case PTP_PF_NONE: + break; + case PTP_PF_EXTTS: + rq.type = PTP_CLK_REQ_EXTTS; + rq.extts.index = chan; + err = ops->enable(ops, &rq, 0); + break; + case PTP_PF_PEROUT: + rq.type = PTP_CLK_REQ_PEROUT; + rq.perout.index = chan; + err = ops->enable(ops, &rq, 0); + break; + case PTP_PF_PHYSYNC: + break; + default: + return -EINVAL; + } + + return err; +} + +int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin, + enum ptp_pin_function func, unsigned int chan) +{ + struct ptp_clock_info *info = ptp->info; + struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin]; + unsigned int i; + + /* Check to see if any other pin previously had this function. */ + if (mutex_lock_interruptible(&ptp->pincfg_mux)) + return -ERESTARTSYS; + for (i = 0; i < info->n_pins; i++) { + if (info->pin_config[i].func == func && + info->pin_config[i].chan == chan) { + pin1 = &info->pin_config[i]; + break; + } + } + mutex_unlock(&ptp->pincfg_mux); + if (pin1 && i == pin) + return 0; + + /* Check the desired function and channel. */ + switch (func) { + case PTP_PF_NONE: + break; + case PTP_PF_EXTTS: + if (chan >= info->n_ext_ts) + return -EINVAL; + break; + case PTP_PF_PEROUT: + if (chan >= info->n_per_out) + return -EINVAL; + break; + case PTP_PF_PHYSYNC: + pr_err("sorry, cannot reassign the calibration pin\n"); + return -EINVAL; + default: + return -EINVAL; + } + + if (pin2->func == PTP_PF_PHYSYNC) { + pr_err("sorry, cannot reprogram the calibration pin\n"); + return -EINVAL; + } + + if (info->verify(info, pin, func, chan)) { + pr_err("driver cannot use function %u on pin %u\n", func, chan); + return -EOPNOTSUPP; + } + + /* Disable whatever function was previously assigned. */ + ptp_disable_pinfunc(info, pin2->func, pin2->chan); + if (pin1) + ptp_disable_pinfunc(info, func, chan); + + if (mutex_lock_interruptible(&ptp->pincfg_mux)) + return -ERESTARTSYS; + pin2->func = func; + pin2->chan = chan; + if (pin1) { + pin1->func = PTP_PF_NONE; + pin1->chan = 0; + } + mutex_unlock(&ptp->pincfg_mux); + + return 0; +} + int ptp_open(struct posix_clock *pc, fmode_t fmode) { return 0; @@ -35,12 +133,13 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) struct ptp_clock_caps caps; struct ptp_clock_request req; struct ptp_sys_offset *sysoff = NULL; + struct ptp_pin_desc pd; struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); struct ptp_clock_info *ops = ptp->info; struct ptp_clock_time *pct; struct timespec ts; int enable, err = 0; - unsigned int i; + unsigned int i, pin_index; switch (cmd) { @@ -51,6 +150,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) caps.n_ext_ts = ptp->info->n_ext_ts; caps.n_per_out = ptp->info->n_per_out; caps.pps = ptp->info->pps; + caps.n_pins = ptp->info->n_pins; if (copy_to_user((void __user *)arg, &caps, sizeof(caps))) err = -EFAULT; break; @@ -126,6 +226,37 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg) err = -EFAULT; break; + case PTP_PIN_GETFUNC: + if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) { + err = -EFAULT; + break; + } + pin_index = pd.index; + if (pin_index >= ops->n_pins) { + err = -EINVAL; + break; + } + if (mutex_lock_interruptible(&ptp->pincfg_mux)) + return -ERESTARTSYS; + pd = ops->pin_config[pin_index]; + mutex_unlock(&ptp->pincfg_mux); + if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd))) + err = -EFAULT; + break; + + case PTP_PIN_SETFUNC: + if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) { + err = -EFAULT; + break; + } + pin_index = pd.index; + if (pin_index >= ops->n_pins) { + err = -EINVAL; + break; + } + err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan); + break; + default: err = -ENOTTY; break; diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index a8319b2..e25d2bc 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -169,6 +169,7 @@ static void delete_ptp_clock(struct posix_clock *pc) struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); mutex_destroy(&ptp->tsevq_mux); + mutex_destroy(&ptp->pincfg_mux); ida_simple_remove(&ptp_clocks_map, ptp->index); kfree(ptp); } @@ -203,6 +204,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, ptp->index = index; spin_lock_init(&ptp->tsevq.lock); mutex_init(&ptp->tsevq_mux); + mutex_init(&ptp->pincfg_mux); init_waitqueue_head(&ptp->tsev_wq); /* Create a new device in our class. */ @@ -249,6 +251,7 @@ no_sysfs: device_destroy(ptp_class, ptp->devid); no_device: mutex_destroy(&ptp->tsevq_mux); + mutex_destroy(&ptp->pincfg_mux); no_slot: kfree(ptp); no_memory: @@ -305,6 +308,26 @@ int ptp_clock_index(struct ptp_clock *ptp) } EXPORT_SYMBOL(ptp_clock_index); +int ptp_find_pin(struct ptp_clock *ptp, + enum ptp_pin_function func, unsigned int chan) +{ + struct ptp_pin_desc *pin = NULL; + int i; + + mutex_lock(&ptp->pincfg_mux); + for (i = 0; i < ptp->info->n_pins; i++) { + if (ptp->info->pin_config[i].func == func && + ptp->info->pin_config[i].chan == chan) { + pin = &ptp->info->pin_config[i]; + break; + } + } + mutex_unlock(&ptp->pincfg_mux); + + return pin ? i : -1; +} +EXPORT_SYMBOL(ptp_find_pin); + /* module operations */ static void __exit ptp_exit(void) diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h index df03f2e..e36bf59 100644 --- a/drivers/ptp/ptp_private.h +++ b/drivers/ptp/ptp_private.h @@ -48,6 +48,7 @@ struct ptp_clock { long dialed_frequency; /* remembers the frequency adjustment */ struct timestamp_event_queue tsevq; /* simple fifo for time stamps */ struct mutex tsevq_mux; /* one process at a time reading the fifo */ + struct mutex pincfg_mux; /* protect concurrent info->pin_config access */ wait_queue_head_t tsev_wq; int defunct; /* tells readers to go away when clock is being removed */ }; @@ -69,6 +70,9 @@ static inline int queue_cnt(struct timestamp_event_queue *q) * see ptp_chardev.c */ +int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin, + enum ptp_pin_function func, unsigned int chan); + long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg); diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h index 38a9935..0d8ff3f 100644 --- a/include/linux/ptp_clock_kernel.h +++ b/include/linux/ptp_clock_kernel.h @@ -49,7 +49,11 @@ struct ptp_clock_request { * @n_alarm: The number of programmable alarms. * @n_ext_ts: The number of external time stamp channels. * @n_per_out: The number of programmable periodic signals. + * @n_pins: The number of programmable pins. * @pps: Indicates whether the clock supports a PPS callback. + * @pin_config: Array of length 'n_pins'. If the number of + * programmable pins is nonzero, then drivers must + * allocate and initialize this array. * * clock operations * @@ -70,6 +74,18 @@ struct ptp_clock_request { * parameter request: Desired resource to enable or disable. * parameter on: Caller passes one to enable or zero to disable. * + * @verify: Confirm that a pin can perform a given function. The PTP + * Hardware Clock subsystem maintains the 'pin_config' + * array on behalf of the drivers, but the PHC subsystem + * assumes that every pin can perform every function. This + * hook gives drivers a way of telling the core about + * limitations on specific pins. This function must return + * zero if the function can be assigned to this pin, and + * nonzero otherwise. + * parameter pin: index of the pin in question. + * parameter func: the desired function to use. + * parameter chan: the function channel index to use. + * * Drivers should embed their ptp_clock_info within a private * structure, obtaining a reference to it using container_of(). * @@ -83,13 +99,17 @@ struct ptp_clock_info { int n_alarm; int n_ext_ts; int n_per_out; + int n_pins; int pps; + struct ptp_pin_desc *pin_config; int (*adjfreq)(struct ptp_clock_info *ptp, s32 delta); int (*adjtime)(struct ptp_clock_info *ptp, s64 delta); int (*gettime)(struct ptp_clock_info *ptp, struct timespec *ts); int (*settime)(struct ptp_clock_info *ptp, const struct timespec *ts); int (*enable)(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on); + int (*verify)(struct ptp_clock_info *ptp, unsigned int pin, + enum ptp_pin_function func, unsigned int chan); }; struct ptp_clock; @@ -156,4 +176,17 @@ extern void ptp_clock_event(struct ptp_clock *ptp, extern int ptp_clock_index(struct ptp_clock *ptp); +/** + * ptp_find_pin() - obtain the pin index of a given auxiliary function + * + * @ptp: The clock obtained from ptp_clock_register(). + * @func: One of the ptp_pin_function enumerated values. + * @chan: The particular functional channel to find. + * Return: Pin index in the range of zero to ptp_clock_caps.n_pins - 1, + * or -1 if the auxiliary function cannot be found. + */ + +int ptp_find_pin(struct ptp_clock *ptp, + enum ptp_pin_function func, unsigned int chan); + #endif diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h index b65c834..f0b7bfe 100644 --- a/include/uapi/linux/ptp_clock.h +++ b/include/uapi/linux/ptp_clock.h @@ -50,7 +50,8 @@ struct ptp_clock_caps { int n_ext_ts; /* Number of external time stamp channels. */ int n_per_out; /* Number of programmable periodic signals. */ int pps; /* Whether the clock supports a PPS callback. */ - int rsv[15]; /* Reserved for future use. */ + int n_pins; /* Number of input/output pins. */ + int rsv[14]; /* Reserved for future use. */ }; struct ptp_extts_request { @@ -80,6 +81,40 @@ struct ptp_sys_offset { struct ptp_clock_time ts[2 * PTP_MAX_SAMPLES + 1]; }; +enum ptp_pin_function { + PTP_PF_NONE, + PTP_PF_EXTTS, + PTP_PF_PEROUT, + PTP_PF_PHYSYNC, +}; + +struct ptp_pin_desc { + /* + * Hardware specific human readable pin name. This field is + * set by the kernel during the PTP_PIN_GETFUNC ioctl and is + * ignored for the PTP_PIN_SETFUNC ioctl. + */ + char name[64]; + /* + * Pin index in the range of zero to ptp_clock_caps.n_pins - 1. + */ + unsigned int index; + /* + * Which of the PTP_PF_xxx functions to use on this pin. + */ + unsigned int func; + /* + * The specific channel to use for this function. + * This corresponds to the 'index' field of the + * PTP_EXTTS_REQUEST and PTP_PEROUT_REQUEST ioctls. + */ + unsigned int chan; + /* + * Reserved for future use. + */ + unsigned int rsv[5]; +}; + #define PTP_CLK_MAGIC '=' #define PTP_CLOCK_GETCAPS _IOR(PTP_CLK_MAGIC, 1, struct ptp_clock_caps) @@ -87,6 +122,8 @@ struct ptp_sys_offset { #define PTP_PEROUT_REQUEST _IOW(PTP_CLK_MAGIC, 3, struct ptp_perout_request) #define PTP_ENABLE_PPS _IOW(PTP_CLK_MAGIC, 4, int) #define PTP_SYS_OFFSET _IOW(PTP_CLK_MAGIC, 5, struct ptp_sys_offset) +#define PTP_PIN_GETFUNC _IOWR(PTP_CLK_MAGIC, 6, struct ptp_pin_desc) +#define PTP_PIN_SETFUNC _IOW(PTP_CLK_MAGIC, 7, struct ptp_pin_desc) struct ptp_extts_event { struct ptp_clock_time t; /* Time event occured. */ -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/