[PATCH v3] Input: analog: Always use ktime functions

From: Guenter Roeck
Date: Tue Sep 07 2021 - 08:37:44 EST


m68k, mips, s390, and sparc allmodconfig images fail to build with the
following error.

drivers/input/joystick/analog.c:160:2: error:
#warning Precise timer not defined for this architecture.

Remove architecture specific time handling code and always use ktime
functions to determine time deltas. Also remove the now useless use_ktime
kernel parameter.

Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
v3: Avoid 64-bit divide operation
v2: Drop helper functions and use ktime_get() and ktime_sub() directly
Drop 'speed' variable and use NSEC_PER_MSEC directly

drivers/input/joystick/analog.c | 103 ++++----------------------------
1 file changed, 11 insertions(+), 92 deletions(-)

diff --git a/drivers/input/joystick/analog.c b/drivers/input/joystick/analog.c
index f798922a4598..824e77da67bb 100644
--- a/drivers/input/joystick/analog.c
+++ b/drivers/input/joystick/analog.c
@@ -28,10 +28,6 @@ MODULE_AUTHOR("Vojtech Pavlik <vojtech@xxxxxx>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

-static bool use_ktime = true;
-module_param(use_ktime, bool, 0400);
-MODULE_PARM_DESC(use_ktime, "Use ktime for measuring I/O speed");
-
/*
* Option parsing.
*/
@@ -110,7 +106,6 @@ struct analog_port {
char cooked;
int bads;
int reads;
- int speed;
int loop;
int fuzz;
int axes[4];
@@ -119,66 +114,6 @@ struct analog_port {
int axtime;
};

-/*
- * Time macros.
- */
-
-#ifdef __i386__
-
-#include <linux/i8253.h>
-
-#define GET_TIME(x) do { if (boot_cpu_has(X86_FEATURE_TSC)) x = (unsigned int)rdtsc(); else x = get_time_pit(); } while (0)
-#define DELTA(x,y) (boot_cpu_has(X86_FEATURE_TSC) ? ((y) - (x)) : ((x) - (y) + ((x) < (y) ? PIT_TICK_RATE / HZ : 0)))
-#define TIME_NAME (boot_cpu_has(X86_FEATURE_TSC)?"TSC":"PIT")
-static unsigned int get_time_pit(void)
-{
- unsigned long flags;
- unsigned int count;
-
- raw_spin_lock_irqsave(&i8253_lock, flags);
- outb_p(0x00, 0x43);
- count = inb_p(0x40);
- count |= inb_p(0x40) << 8;
- raw_spin_unlock_irqrestore(&i8253_lock, flags);
-
- return count;
-}
-#elif defined(__x86_64__)
-#define GET_TIME(x) do { x = (unsigned int)rdtsc(); } while (0)
-#define DELTA(x,y) ((y)-(x))
-#define TIME_NAME "TSC"
-#elif defined(__alpha__) || defined(CONFIG_ARM) || defined(CONFIG_ARM64) || defined(CONFIG_PPC) || defined(CONFIG_RISCV)
-#define GET_TIME(x) do { x = get_cycles(); } while (0)
-#define DELTA(x,y) ((y)-(x))
-#define TIME_NAME "get_cycles"
-#else
-#define FAKE_TIME
-static unsigned long analog_faketime = 0;
-#define GET_TIME(x) do { x = analog_faketime++; } while(0)
-#define DELTA(x,y) ((y)-(x))
-#define TIME_NAME "Unreliable"
-#warning Precise timer not defined for this architecture.
-#endif
-
-static inline u64 get_time(void)
-{
- if (use_ktime) {
- return ktime_get_ns();
- } else {
- unsigned int x;
- GET_TIME(x);
- return x;
- }
-}
-
-static inline unsigned int delta(u64 x, u64 y)
-{
- if (use_ktime)
- return y - x;
- else
- return DELTA((unsigned int)x, (unsigned int)y);
-}
-
/*
* analog_decode() decodes analog joystick data and reports input events.
*/
@@ -241,11 +176,11 @@ static int analog_cooked_read(struct analog_port *port)
int i, j;

loopout = (ANALOG_LOOP_TIME * port->loop) / 1000;
- timeout = ANALOG_MAX_TIME * port->speed;
+ timeout = ANALOG_MAX_TIME * NSEC_PER_MSEC;

local_irq_save(flags);
gameport_trigger(gameport);
- now = get_time();
+ now = ktime_get();
local_irq_restore(flags);

start = now;
@@ -258,16 +193,16 @@ static int analog_cooked_read(struct analog_port *port)

local_irq_disable();
this = gameport_read(gameport) & port->mask;
- now = get_time();
+ now = ktime_get();
local_irq_restore(flags);

- if ((last ^ this) && (delta(loop, now) < loopout)) {
+ if ((last ^ this) && (ktime_sub(now, loop) < loopout)) {
data[i] = last ^ this;
time[i] = now;
i++;
}

- } while (this && (i < 4) && (delta(start, now) < timeout));
+ } while (this && (i < 4) && (ktime_sub(now, start) < timeout));

this <<= 4;

@@ -275,7 +210,7 @@ static int analog_cooked_read(struct analog_port *port)
this |= data[i];
for (j = 0; j < 4; j++)
if (data[i] & (1 << j))
- port->axes[j] = (delta(start, time[i]) << ANALOG_FUZZ_BITS) / port->loop;
+ port->axes[j] = ((u32)ktime_sub(time[i], start) << ANALOG_FUZZ_BITS) / port->loop;
}

return -(this != port->mask);
@@ -378,35 +313,19 @@ static void analog_calibrate_timer(struct analog_port *port)
u64 t1, t2, t3;
unsigned long flags;

- if (use_ktime) {
- port->speed = 1000000;
- } else {
- local_irq_save(flags);
- t1 = get_time();
-#ifdef FAKE_TIME
- analog_faketime += 830;
-#endif
- mdelay(1);
- t2 = get_time();
- t3 = get_time();
- local_irq_restore(flags);
-
- port->speed = delta(t1, t2) - delta(t2, t3);
- }
-
tx = ~0;

for (i = 0; i < 50; i++) {
local_irq_save(flags);
- t1 = get_time();
+ t1 = ktime_get();
for (t = 0; t < 50; t++) {
gameport_read(gameport);
- t2 = get_time();
+ t2 = ktime_get();
}
- t3 = get_time();
+ t3 = ktime_get();
local_irq_restore(flags);
udelay(i);
- t = delta(t1, t2) - delta(t2, t3);
+ t = ktime_sub(t2, t1) - ktime_sub(t3, t2);
if (t < tx) tx = t;
}

@@ -611,7 +530,7 @@ static int analog_init_port(struct gameport *gameport, struct gameport_driver *d
t = gameport_read(gameport);
msleep(ANALOG_MAX_TIME);
port->mask = (gameport_read(gameport) ^ t) & t & 0xf;
- port->fuzz = (port->speed * ANALOG_FUZZ_MAGIC) / port->loop / 1000 + ANALOG_FUZZ_BITS;
+ port->fuzz = (NSEC_PER_MSEC * ANALOG_FUZZ_MAGIC) / port->loop / 1000 + ANALOG_FUZZ_BITS;

for (i = 0; i < ANALOG_INIT_RETRIES; i++) {
if (!analog_cooked_read(port))
--
2.33.0