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
......@@ -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;
......
......@@ -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 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
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)
......
......@@ -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);
......
......@@ -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
......@@ -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. */
......
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