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ptp: introduce programmable pins.

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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 <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Richard Cochran
2014-03-20 22:21:52 +01:00
committed by David S. Miller
parent a85ae0e978
commit 6092315dfd
5 changed files with 226 additions and 2 deletions
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33
include/linux/ptp_clock_kernel.h
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@@ -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