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X1000: remove bogus GPIO Z mutex

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There's absolutely no way for gpio_config() to get called from two
different threads due to the co-operative threading model, and it
is unsafe to call from IRQ context no matter what we do.

Change-Id: I58f7d1f68c7a414610bb020e26b774cb1015a3b0
This commit is contained in:
Aidan MacDonald 2021-04-25 14:17:45 +01:00
parent a2dfafb2b2
commit 77188e41f5
2 changed files with 4 additions and 31 deletions
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24
firmware/target/mips/ingenic_x1000/gpio-x1000.c
View file

@ -22,16 +22,8 @@
#include "gpio-x1000.h"
#include "kernel.h"
#ifndef BOOTLOADER_SPL
struct mutex gpio_z_mutex;
#endif
void gpio_init(void)
{
#ifndef BOOTLOADER_SPL
mutex_init(&gpio_z_mutex);
#endif
/* Any GPIO pins left in an IRQ trigger state need to be switched off,
* because the drivers won't be ready to handle the interrupts until they
* get initialized later in the boot. */
@ -44,20 +36,6 @@ void gpio_init(void)
}
}
void gpio_lock(void)
{
#ifndef BOOTLOADER_SPL
mutex_lock(&gpio_z_mutex);
#endif
}
void gpio_unlock(void)
{
#ifndef BOOTLOADER_SPL
mutex_unlock(&gpio_z_mutex);
#endif
}
void gpio_config(int port, unsigned pinmask, int func)
{
unsigned intr = REG_GPIO_INT(port);
@ -65,7 +43,6 @@ void gpio_config(int port, unsigned pinmask, int func)
unsigned pat1 = REG_GPIO_PAT1(port);
unsigned pat0 = REG_GPIO_PAT0(port);
gpio_lock();
if(func & 8) jz_set(GPIO_INT(GPIO_Z), (intr & pinmask) ^ pinmask);
else jz_clr(GPIO_INT(GPIO_Z), (~intr & pinmask) ^ pinmask);
if(func & 4) jz_set(GPIO_MSK(GPIO_Z), (mask & pinmask) ^ pinmask);
@ -75,6 +52,5 @@ void gpio_config(int port, unsigned pinmask, int func)
if(func & 1) jz_set(GPIO_PAT0(GPIO_Z), (pat0 & pinmask) ^ pinmask);
else jz_clr(GPIO_PAT0(GPIO_Z), (~pat0 & pinmask) ^ pinmask);
REG_GPIO_Z_GID2LD = port;
gpio_unlock();
gpio_set_pull(port, pinmask, func & 16);
}

11
firmware/target/mips/ingenic_x1000/gpio-x1000.h
View file

@ -26,12 +26,11 @@
* --------
*
* To assign a new function to a GPIO, call gpio_config(). This uses the
* hardware's GPIO Z facility to atomically most GPIO registers at once,
* hardware's GPIO Z facility to atomically set most GPIO registers at once,
* so it can be used to make any state transition safely. Since GPIO Z is
* protected by a mutex, you can't call gpio_config() from interrupt context.
*
* If you need to use GPIO Z directly, then use gpio_lock() and gpio_unlock()
* to acquire the mutex.
* a global hardware resource, it is unsafe to call gpio_config() from IRQ
* context -- if the interrupted code was also running gpio_config(), then
* the results would be unpredictable.
*
* Depending on the current GPIO state, certain state transitions are safe to
* perform without locking, as they only change one register:
@ -74,8 +73,6 @@
#define GPIO_IRQ_EDGE(i) (0x1e|((i)&1))
extern void gpio_init(void);
extern void gpio_lock(void);
extern void gpio_unlock(void);
extern void gpio_config(int port, unsigned pinmask, int func);
static inline void gpio_out_level(int port, unsigned pinmask, int level)