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>

1 files changed, 72 insertions, 15 deletions

diff --git a/arch/blackfin/mach-bf548/gpio.c b/arch/blackfin/mach-bf548/gpio.c
index 0da5f0003b8c..c073ab36066d 100644
--- 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;
 }