Blackfin arch: store labels so we later know who allocated GPIO/Peripheral resources

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/arch/blackfin/mach-bf548/gpio.c b/arch/blackfin/mach-bf548/gpio.c
index 0da5f00..c073ab3 100644 (file)
--- a/arch/blackfin/mach-bf548/gpio.c
+++ b/arch/blackfin/mach-bf548/gpio.c
@@ -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)
 {
@@ -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)
@@ -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);
@@ -98,6 +95,11 @@ 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;
@@ -105,11 +107,47 @@ static int __init bfin_gpio_init(void)
 
 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;
 
@@ -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;
@@ -131,22 +169,38 @@ 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;
 }
@@ -154,7 +208,6 @@ EXPORT_SYMBOL(peripheral_request);
 
 int peripheral_request_list(unsigned short per[], const char *label)
 {
-
        u16 cnt;
        int ret;
 
@@ -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;
 
@@ -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;
        }
@@ -234,7 +288,8 @@ 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;
@@ -242,7 +297,8 @@ int gpio_request(unsigned short gpio, const char *label)
 
        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;
@@ -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;
 }

diff --git a/include/asm-blackfin/mach-bf548/gpio.h b/include/asm-blackfin/mach-bf548/gpio.h
index dbf66bc..cb8b0f1 100644 (file)
--- a/include/asm-blackfin/mach-bf548/gpio.h
+++ b/include/asm-blackfin/mach-bf548/gpio.h
@@ -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[]);