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Blackfin arch: store labels so we later know who allocated GPIO/Perip…
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…heral resources

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
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Michael Hennerich authored and Bryan Wu committed Oct 10, 2007
1 parent b2d1583 commit 40d6340
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Showing 2 changed files with 72 additions and 20 deletions.
87 changes: 72 additions & 15 deletions arch/blackfin/mach-bf548/gpio.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,9 @@ static struct gpio_port_t *gpio_array[gpio_bank(MAX_BLACKFIN_GPIOS)] = {

static unsigned short reserved_gpio_map[gpio_bank(MAX_BLACKFIN_GPIOS)];
static unsigned short reserved_peri_map[gpio_bank(MAX_BLACKFIN_GPIOS)];
char *str_ident = NULL;

#define RESOURCE_LABEL_SIZE 16

inline int check_gpio(unsigned short gpio)
{
Expand All @@ -70,7 +73,6 @@ inline void portmux_setup(unsigned short portno, unsigned short function)
pmux |= (function & 0x3) << (2 * gpio_sub_n(portno));

gpio_array[gpio_bank(portno)]->port_mux = pmux;

}

inline u16 get_portmux(unsigned short portno)
Expand All @@ -80,16 +82,11 @@ inline u16 get_portmux(unsigned short portno)
pmux = gpio_array[gpio_bank(portno)]->port_mux;

return (pmux >> (2 * gpio_sub_n(portno)) & 0x3);

}

static void port_setup(unsigned short gpio, unsigned short usage)
{
if (usage == GPIO_USAGE) {
if (gpio_array[gpio_bank(gpio)]->port_fer & gpio_bit(gpio))
printk(KERN_WARNING
"bfin-gpio: Possible Conflict with Peripheral "
"usage and GPIO %d detected!\n", gpio);
gpio_array[gpio_bank(gpio)]->port_fer &= ~gpio_bit(gpio);
} else
gpio_array[gpio_bank(gpio)]->port_fer |= gpio_bit(gpio);
Expand All @@ -98,18 +95,59 @@ static void port_setup(unsigned short gpio, unsigned short usage)

static int __init bfin_gpio_init(void)
{

str_ident = kzalloc(RESOURCE_LABEL_SIZE * 256, GFP_KERNEL);
if (!str_ident)
return -ENOMEM;

printk(KERN_INFO "Blackfin GPIO Controller\n");

return 0;
}

arch_initcall(bfin_gpio_init);

static void set_label(unsigned short ident, const char *label)
{

if (label && str_ident) {
strncpy(str_ident + ident * RESOURCE_LABEL_SIZE, label,
RESOURCE_LABEL_SIZE);
str_ident[ident * RESOURCE_LABEL_SIZE +
RESOURCE_LABEL_SIZE - 1] = 0;
}
}

static char *get_label(unsigned short ident)
{
if (!str_ident)
return "UNKNOWN";

return (str_ident[ident * RESOURCE_LABEL_SIZE] ?
(str_ident + ident * RESOURCE_LABEL_SIZE) : "UNKNOWN");
}

static int cmp_label(unsigned short ident, const char *label)
{
if (label && str_ident)
return strncmp(str_ident + ident * RESOURCE_LABEL_SIZE,
label, strlen(label));
else
return -EINVAL;
}

int peripheral_request(unsigned short per, const char *label)
{
unsigned long flags;
unsigned short ident = P_IDENT(per);

/*
* Don't cares are pins with only one dedicated function
*/

if (per & P_DONTCARE)
return 0;

if (!(per & P_DEFINED))
return -ENODEV;

Expand All @@ -120,8 +158,8 @@ int peripheral_request(unsigned short per, const char *label)

if (unlikely(reserved_gpio_map[gpio_bank(ident)] & gpio_bit(ident))) {
printk(KERN_ERR
"%s: Peripheral %d is already reserved as GPIO!\n",
__FUNCTION__, per);
"%s: Peripheral %d is already reserved as GPIO by %s !\n",
__FUNCTION__, ident, get_label(ident));
dump_stack();
local_irq_restore(flags);
return -EBUSY;
Expand All @@ -131,30 +169,45 @@ int peripheral_request(unsigned short per, const char *label)

u16 funct = get_portmux(ident);

/*
* Pin functions like AMC address strobes my
* be requested and used by several drivers
*/

if (!((per & P_MAYSHARE) && (funct == P_FUNCT2MUX(per)))) {

/*
* Allow that the identical pin function can
* be requested from the same driver twice
*/

if (cmp_label(ident, label) == 0)
goto anyway;

printk(KERN_ERR
"%s: Peripheral %d is already reserved!\n",
__FUNCTION__, per);
"%s: Peripheral %d function %d is already reserved by %s !\n",
__FUNCTION__, ident, P_FUNCT2MUX(per), get_label(ident));
dump_stack();
local_irq_restore(flags);
return -EBUSY;
}
}

anyway:
reserved_peri_map[gpio_bank(ident)] |= gpio_bit(ident);

portmux_setup(ident, P_FUNCT2MUX(per));
port_setup(ident, PERIPHERAL_USAGE);

local_irq_restore(flags);
set_label(ident, label);

return 0;
}
EXPORT_SYMBOL(peripheral_request);

int peripheral_request_list(unsigned short per[], const char *label)
{

u16 cnt;
int ret;

Expand All @@ -173,6 +226,9 @@ void peripheral_free(unsigned short per)
unsigned long flags;
unsigned short ident = P_IDENT(per);

if (per & P_DONTCARE)
return;

if (!(per & P_DEFINED))
return;

Expand All @@ -182,8 +238,6 @@ void peripheral_free(unsigned short per)
local_irq_save(flags);

if (unlikely(!(reserved_peri_map[gpio_bank(ident)] & gpio_bit(ident)))) {
printk(KERN_ERR "bfin-gpio: Peripheral %d wasn't reserved!\n", per);
dump_stack();
local_irq_restore(flags);
return;
}
Expand Down Expand Up @@ -234,15 +288,17 @@ int gpio_request(unsigned short gpio, const char *label)
local_irq_save(flags);

if (unlikely(reserved_gpio_map[gpio_bank(gpio)] & gpio_bit(gpio))) {
printk(KERN_ERR "bfin-gpio: GPIO %d is already reserved!\n", gpio);
printk(KERN_ERR "bfin-gpio: GPIO %d is already reserved by %s !\n",
gpio, get_label(gpio));
dump_stack();
local_irq_restore(flags);
return -EBUSY;
}

if (unlikely(reserved_peri_map[gpio_bank(gpio)] & gpio_bit(gpio))) {
printk(KERN_ERR
"bfin-gpio: GPIO %d is already reserved as Peripheral!\n", gpio);
"bfin-gpio: GPIO %d is already reserved as Peripheral by %s !\n",
gpio, get_label(gpio));
dump_stack();
local_irq_restore(flags);
return -EBUSY;
Expand All @@ -253,6 +309,7 @@ int gpio_request(unsigned short gpio, const char *label)
local_irq_restore(flags);

port_setup(gpio, GPIO_USAGE);
set_label(gpio, label);

return 0;
}
Expand Down
5 changes: 0 additions & 5 deletions include/asm-blackfin/mach-bf548/gpio.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -209,8 +209,3 @@ struct gpio_port_t {
unsigned short dummy7;
unsigned int port_mux;
};

int gpio_request(unsigned short gpio, const char *label);
void peripheral_free(unsigned short per);
int peripheral_request_list(unsigned short per[], const char *label);
void peripheral_free_list(unsigned short per[]);

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