[ARM] 4669/1: ep93xx: simplify GPIO code and cleanups

This patch renumbers the (virtual) GPIO line numbering to have all
irq-capable gpio lines <= EP93XX_GPIO_LINE_MAX_IRQ by swapping the
port f range with the port c range; This simplifies code such as

 #define IRQ_EP93XX_GPIO(x)  (64 + (((x) + (((x) >> 2) & 8)) & 0x1f))

or

 if (line >= 0 && line < 16) {
    /* Port A/B */
 } else if (line >= 40 && line < 48) {
    /* Port F */
 }

considerably; in addition to the renumbering this patch also
introduces macro constants EP93XX_GPIO_LINE_MAX_IRQ and
EP93XX_GPIO_LINE_MAX, and replaces most magic numbers by those and
invocations of gpio_to_irq()/irq_to_gpio().

Signed-off-by: Herbert Valerio Riedel <hvr@gnu.org>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 70 insertions, 77 deletions

diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index 8a734066137..58957d7a576 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -157,35 +157,35 @@ static unsigned char gpio_int_enabled[3];
 static unsigned char gpio_int_type1[3];
 static unsigned char gpio_int_type2[3];
 
-static void update_gpio_int_params(int abf)
+/* Port ordering is: A B F */
+static const u8 int_type1_register_offset[3]    = { 0x90, 0xac, 0x4c };
+static const u8 int_type2_register_offset[3]    = { 0x94, 0xb0, 0x50 };
+static const u8 eoi_register_offset[3]          = { 0x98, 0xb4, 0x54 };
+static const u8 int_en_register_offset[3]       = { 0x9c, 0xb8, 0x5c };
+
+static void update_gpio_int_params(unsigned port)
 {
-        if (abf == 0) {
-                __raw_writeb(0, EP93XX_GPIO_A_INT_ENABLE);
-                __raw_writeb(gpio_int_type2[0], EP93XX_GPIO_A_INT_TYPE2);
-                __raw_writeb(gpio_int_type1[0], EP93XX_GPIO_A_INT_TYPE1);
-                __raw_writeb(gpio_int_unmasked[0] & gpio_int_enabled[0], EP93XX_GPIO_A_INT_ENABLE);
-        } else if (abf == 1) {
-                __raw_writeb(0, EP93XX_GPIO_B_INT_ENABLE);
-                __raw_writeb(gpio_int_type2[1], EP93XX_GPIO_B_INT_TYPE2);
-                __raw_writeb(gpio_int_type1[1], EP93XX_GPIO_B_INT_TYPE1);
-                __raw_writeb(gpio_int_unmasked[1] & gpio_int_enabled[1], EP93XX_GPIO_B_INT_ENABLE);
-        } else if (abf == 2) {
-                __raw_writeb(0, EP93XX_GPIO_F_INT_ENABLE);
-                __raw_writeb(gpio_int_type2[2], EP93XX_GPIO_F_INT_TYPE2);
-                __raw_writeb(gpio_int_type1[2], EP93XX_GPIO_F_INT_TYPE1);
-                __raw_writeb(gpio_int_unmasked[2] & gpio_int_enabled[2], EP93XX_GPIO_F_INT_ENABLE);
-        } else {
-                BUG();
-        }
-}
+        BUG_ON(port > 2);
 
+        __raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
+
+        __raw_writeb(gpio_int_type2[port],
+                EP93XX_GPIO_REG(int_type2_register_offset[port]));
+
+        __raw_writeb(gpio_int_type1[port],
+                EP93XX_GPIO_REG(int_type1_register_offset[port]));
+
+        __raw_writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
+                EP93XX_GPIO_REG(int_en_register_offset[port]));
+}
 
-static unsigned char data_register_offset[8] = {
-        0x00, 0x04, 0x08, 0x0c, 0x20, 0x30, 0x38, 0x40,
+/* Port ordering is: A B F D E C G H */
+static const u8 data_register_offset[8] = {
+        0x00, 0x04, 0x30, 0x0c, 0x20, 0x08, 0x38, 0x40,
 };
 
-static unsigned char data_direction_register_offset[8] = {
-        0x10, 0x14, 0x18, 0x1c, 0x24, 0x34, 0x3c, 0x44,
+static const u8 data_direction_register_offset[8] = {
+        0x10, 0x14, 0x34, 0x1c, 0x24, 0x18, 0x3c, 0x44,
 };
 
 static void ep93xx_gpio_set_direction(unsigned line, int direction)
@@ -199,14 +199,10 @@ static void ep93xx_gpio_set_direction(unsigned line, int direction)
 
         local_irq_save(flags);
         if (direction == GPIO_OUT) {
-                if (line >= 0 && line < 16) {
-                        /* Port A/B.  */
+                if (line >= 0 && line <= EP93XX_GPIO_LINE_MAX_IRQ) {
+                        /* Port A/B/F */
                         gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
                         update_gpio_int_params(line >> 3);
-                } else if (line >= 40 && line < 48) {
-                        /* Port F.  */
-                        gpio_int_unmasked[2] &= ~(1 << (line & 7));
-                        update_gpio_int_params(2);
                 }
 
                 v = __raw_readb(data_direction_register);
@@ -228,7 +224,7 @@ EXPORT_SYMBOL(gpio_line_config);
 
 int gpio_direction_input(unsigned gpio)
 {
-        if (gpio > EP93XX_GPIO_LINE_H(7))
+        if (gpio > EP93XX_GPIO_LINE_MAX)
                 return -EINVAL;
 
         ep93xx_gpio_set_direction(gpio, GPIO_IN);
@@ -239,7 +235,7 @@ EXPORT_SYMBOL(gpio_direction_input);
 
 int gpio_direction_output(unsigned gpio, int value)
 {
-        if (gpio > EP93XX_GPIO_LINE_H(7))
+        if (gpio > EP93XX_GPIO_LINE_MAX)
                 return -EINVAL;
 
         gpio_set_value(gpio, value);
@@ -290,47 +286,50 @@ static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
         status = __raw_readb(EP93XX_GPIO_A_INT_STATUS);
         for (i = 0; i < 8; i++) {
                 if (status & (1 << i)) {
-                        desc = irq_desc + IRQ_EP93XX_GPIO(0) + i;
-                        desc_handle_irq(IRQ_EP93XX_GPIO(0) + i, desc);
+                        int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
+                        desc = irq_desc + gpio_irq;
+                        desc_handle_irq(gpio_irq, desc);
                 }
         }
 
         status = __raw_readb(EP93XX_GPIO_B_INT_STATUS);
         for (i = 0; i < 8; i++) {
                 if (status & (1 << i)) {
-                        desc = irq_desc + IRQ_EP93XX_GPIO(8) + i;
-                        desc_handle_irq(IRQ_EP93XX_GPIO(8) + i, desc);
+                        int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
+                        desc = irq_desc + gpio_irq;
+                        desc_handle_irq(gpio_irq, desc);
                 }
         }
 }
 
 static void ep93xx_gpio_f_irq_handler(unsigned int irq, struct irq_desc *desc)
 {
-        int gpio_irq = IRQ_EP93XX_GPIO(16) + (((irq + 1) & 7) ^ 4);
+        /*
+         * map discontiguous hw irq range to continous sw irq range:
+         *
+         *  IRQ_EP93XX_GPIO{0..7}MUX -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
+         */
+        int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
+        int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
 
         desc_handle_irq(gpio_irq, irq_desc + gpio_irq);
 }
 
 static void ep93xx_gpio_irq_mask_ack(unsigned int irq)
 {
-        int line = irq - IRQ_EP93XX_GPIO(0);
+        int line = irq_to_gpio(irq);
         int port = line >> 3;
+        int port_mask = 1 << (line & 7);
 
-        gpio_int_unmasked[port] &= ~(1 << (line & 7));
+        gpio_int_unmasked[port] &= ~port_mask;
         update_gpio_int_params(port);
 
-        if (port == 0) {
-                __raw_writel(1 << (line & 7), EP93XX_GPIO_A_INT_ACK);
-        } else if (port == 1) {
-                __raw_writel(1 << (line & 7), EP93XX_GPIO_B_INT_ACK);
-        } else if (port == 2) {
-                __raw_writel(1 << (line & 7), EP93XX_GPIO_F_INT_ACK);
-        }
+        __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
 }
 
 static void ep93xx_gpio_irq_mask(unsigned int irq)
 {
-        int line = irq - IRQ_EP93XX_GPIO(0);
+        int line = irq_to_gpio(irq);
         int port = line >> 3;
 
         gpio_int_unmasked[port] &= ~(1 << (line & 7));
@@ -339,7 +338,7 @@ static void ep93xx_gpio_irq_mask(unsigned int irq)
 
 static void ep93xx_gpio_irq_unmask(unsigned int irq)
 {
-        int line = irq - IRQ_EP93XX_GPIO(0);
+        int line = irq_to_gpio(irq);
         int port = line >> 3;
 
         gpio_int_unmasked[port] |= 1 << (line & 7);
@@ -354,37 +353,30 @@ static void ep93xx_gpio_irq_unmask(unsigned int irq)
  */
 static int ep93xx_gpio_irq_type(unsigned int irq, unsigned int type)
 {
-        int port;
-        int line;
+        const int gpio = irq_to_gpio(irq);
+        const int port = gpio >> 3;
+        const int port_mask = 1 << (gpio & 7);
 
-        line = irq - IRQ_EP93XX_GPIO(0);
-        if (line >= 0 && line < 16) {
-                ep93xx_gpio_set_direction(line, GPIO_IN);
-        } else {
-                ep93xx_gpio_set_direction(EP93XX_GPIO_LINE_F(line-16), GPIO_IN);
-        }
-
-        port = line >> 3;
-        line &= 7;
+        ep93xx_gpio_set_direction(gpio, GPIO_IN);
 
         if (type & IRQT_RISING) {
-                gpio_int_enabled[port] |= 1 << line;
-                gpio_int_type1[port] |= 1 << line;
-                gpio_int_type2[port] |= 1 << line;
+                gpio_int_enabled[port] |= port_mask;
+                gpio_int_type1[port] |= port_mask;
+                gpio_int_type2[port] |= port_mask;
         } else if (type & IRQT_FALLING) {
-                gpio_int_enabled[port] |= 1 << line;
-                gpio_int_type1[port] |= 1 << line;
-                gpio_int_type2[port] &= ~(1 << line);
+                gpio_int_enabled[port] |= port_mask;
+                gpio_int_type1[port] |= port_mask;
+                gpio_int_type2[port] &= ~port_mask;
         } else if (type & IRQT_HIGH) {
-                gpio_int_enabled[port] |= 1 << line;
-                gpio_int_type1[port] &= ~(1 << line);
-                gpio_int_type2[port] |= 1 << line;
+                gpio_int_enabled[port] |= port_mask;
+                gpio_int_type1[port] &= ~port_mask;
+                gpio_int_type2[port] |= port_mask;
         } else if (type & IRQT_LOW) {
-                gpio_int_enabled[port] |= 1 << line;
-                gpio_int_type1[port] &= ~(1 << line);
-                gpio_int_type2[port] &= ~(1 << line);
+                gpio_int_enabled[port] |= port_mask;
+                gpio_int_type1[port] &= ~port_mask;
+                gpio_int_type2[port] &= ~port_mask;
         } else {
-                gpio_int_enabled[port] &= ~(1 << line);
+                gpio_int_enabled[port] &= ~port_mask;
         }
         update_gpio_int_params(port);
 
@@ -402,15 +394,16 @@ static struct irq_chip ep93xx_gpio_irq_chip = {
 
 void __init ep93xx_init_irq(void)
 {
-        int irq;
+        int gpio_irq;
 
         vic_init((void *)EP93XX_VIC1_BASE, 0, EP93XX_VIC1_VALID_IRQ_MASK);
         vic_init((void *)EP93XX_VIC2_BASE, 32, EP93XX_VIC2_VALID_IRQ_MASK);
 
-        for (irq = IRQ_EP93XX_GPIO(0); irq <= IRQ_EP93XX_GPIO(23); irq++) {
-                set_irq_chip(irq, &ep93xx_gpio_irq_chip);
-                set_irq_handler(irq, handle_level_irq);
-                set_irq_flags(irq, IRQF_VALID);
+        for (gpio_irq = gpio_to_irq(0);
+             gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
+                set_irq_chip(gpio_irq, &ep93xx_gpio_irq_chip);
+                set_irq_handler(gpio_irq, handle_level_irq);
+                set_irq_flags(gpio_irq, IRQF_VALID);
         }
 
         set_irq_chained_handler(IRQ_EP93XX_GPIO_AB, ep93xx_gpio_ab_irq_handler);