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Commit 6092315d authored by Richard Cochran's avatar Richard Cochran Committed by David S. Miller
Browse files

ptp: introduce programmable pins. 



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: default avatarRichard Cochran <richardcochran@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a85ae0e9

drivers/ptp/ptp_chardev.c

+127 −1
Original line number Diff line number Diff line
@@ -25,6 +25,96 @@ 


#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. */

	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;

		}

	}

	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. */

	if (pin1) {

		ptp_disable_pinfunc(info, func, chan);

		pin1->func = PTP_PF_NONE;

		pin1->chan = 0;

	}

	ptp_disable_pinfunc(info, pin2->func, pin2->chan);

	pin2->func = func;

	pin2->chan = chan;



	return 0;

}



int ptp_open(struct posix_clock *pc, fmode_t fmode)

{

	return 0;
@@ -35,12 +125,13 @@ 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 +142,7 @@ 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 +218,40 @@ 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;

		}

		if (mutex_lock_interruptible(&ptp->pincfg_mux))

			return -ERESTARTSYS;

		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);

		mutex_unlock(&ptp->pincfg_mux);

		break;



	default:

		err = -ENOTTY;

		break;

drivers/ptp/ptp_clock.c

+23 −0
Original line number Diff line number Diff line
@@ -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)

drivers/ptp/ptp_private.h

+5 −0
Original line number Diff line number Diff line
@@ -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 +70,10 @@ static inline int queue_cnt(struct timestamp_event_queue *q) 
 * see ptp_chardev.c

 */



/* caller must hold pincfg_mux */

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);

include/linux/ptp_clock_kernel.h

+33 −0
Original line number Diff line number Diff line
@@ -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

include/uapi/linux/ptp_clock.h

+38 −1
Original line number Diff line number Diff line
@@ -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. */