misc: panel, convert struct to bitmap

There is an anonymous struct which is actually used as a bitmap. So
convert the struct to a bitmap and change code accordingly where
needed.

This also allows for a cleanup of set_data_bits and set_ctrl_bits as
they can use a common helper now. The helper can also be converted to
a for loop instead of doing bit OR. And given it is a for loop now,
bit masking (using BIT_MSK) is moved from the callers there too.

Signed-off-by: Daniel Chromik <[e-mail]>
Signed-off-by: Jiri Slaby <[e-mail]>
Cc: Ksenija Stanojevic <[e-mail]>
Acked-by: Willy Tarreau <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/panel.c

···
 
 static const char (*keypad_profile)[4][9] = old_keypad_profile;
 
-/* FIXME: this should be converted to a bit array containing signals states */
-static struct {
-	unsigned char e;  /* parallel LCD E (data latch on falling edge) */
-	unsigned char rs; /* parallel LCD RS  (0 = cmd, 1 = data) */
-	unsigned char rw; /* parallel LCD R/W (0 = W, 1 = R) */
-	unsigned char bl; /* parallel LCD backlight (0 = off, 1 = on) */
-	unsigned char cl; /* serial LCD clock (latch on rising edge) */
-	unsigned char da; /* serial LCD data */
-} bits;
+static DECLARE_BITMAP(bits, LCD_BITS);
+
+static void lcd_get_bits(unsigned int port, int *val)
+{
+	unsigned int bit, state;
+
+	for (bit = 0; bit < LCD_BITS; bit++) {
+		state = test_bit(bit, bits) ? BIT_SET : BIT_CLR;
+		*val &= lcd_bits[port][bit][BIT_MSK];
+		*val |= lcd_bits[port][bit][state];
+	}
+}
 
 static void init_scan_timer(void);
 
 /* sets data port bits according to current signals values */
 static int set_data_bits(void)
 {
-	int val, bit;
+	int val;
 
 	val = r_dtr(pprt);
-	for (bit = 0; bit < LCD_BITS; bit++)
-		val &= lcd_bits[LCD_PORT_D][bit][BIT_MSK];
-
-	val |= lcd_bits[LCD_PORT_D][LCD_BIT_E][bits.e]
-	    | lcd_bits[LCD_PORT_D][LCD_BIT_RS][bits.rs]
-	    | lcd_bits[LCD_PORT_D][LCD_BIT_RW][bits.rw]
-	    | lcd_bits[LCD_PORT_D][LCD_BIT_BL][bits.bl]
-	    | lcd_bits[LCD_PORT_D][LCD_BIT_CL][bits.cl]
-	    | lcd_bits[LCD_PORT_D][LCD_BIT_DA][bits.da];
-
+	lcd_get_bits(LCD_PORT_D, &val);
 	w_dtr(pprt, val);
 	return val;
 }
···
 /* sets ctrl port bits according to current signals values */
 static int set_ctrl_bits(void)
 {
-	int val, bit;
+	int val;
 
 	val = r_ctr(pprt);
-	for (bit = 0; bit < LCD_BITS; bit++)
-		val &= lcd_bits[LCD_PORT_C][bit][BIT_MSK];
-
-	val |= lcd_bits[LCD_PORT_C][LCD_BIT_E][bits.e]
-	    | lcd_bits[LCD_PORT_C][LCD_BIT_RS][bits.rs]
-	    | lcd_bits[LCD_PORT_C][LCD_BIT_RW][bits.rw]
-	    | lcd_bits[LCD_PORT_C][LCD_BIT_BL][bits.bl]
-	    | lcd_bits[LCD_PORT_C][LCD_BIT_CL][bits.cl]
-	    | lcd_bits[LCD_PORT_C][LCD_BIT_DA][bits.da];
-
+	lcd_get_bits(LCD_PORT_C, &val);
 	w_ctr(pprt, val);
 	return val;
 }
···
 	 * LCD reads D0 on STROBE's rising edge.
 	 */
 	for (bit = 0; bit < 8; bit++) {
-		bits.cl = BIT_CLR;	/* CLK low */
+		clear_bit(LCD_BIT_CL, bits);	/* CLK low */
 		panel_set_bits();
-		bits.da = byte & 1;
+		if (byte & 1) {
+			set_bit(LCD_BIT_DA, bits);
+		} else {
+			clear_bit(LCD_BIT_DA, bits);
+		}
+
 		panel_set_bits();
 		udelay(2);  /* maintain the data during 2 us before CLK up */
-		bits.cl = BIT_SET;	/* CLK high */
+		set_bit(LCD_BIT_CL, bits);	/* CLK high */
 		panel_set_bits();
 		udelay(1);  /* maintain the strobe during 1 us */
 		byte >>= 1;
···
 
 	/* The backlight is activated by setting the AUTOFEED line to +5V  */
 	spin_lock_irq(&pprt_lock);
-	bits.bl = on;
+	if (on)
+		set_bit(LCD_BIT_BL, bits);
+	else
+		clear_bit(LCD_BIT_BL, bits);
 	panel_set_bits();
 	spin_unlock_irq(&pprt_lock);
 }
···
 	w_dtr(pprt, cmd);
 	udelay(20);	/* maintain the data during 20 us before the strobe */
 
-	bits.e = BIT_SET;
-	bits.rs = BIT_CLR;
-	bits.rw = BIT_CLR;
+	set_bit(LCD_BIT_E, bits);
+	clear_bit(LCD_BIT_RS, bits);
+	clear_bit(LCD_BIT_RW, bits);
 	set_ctrl_bits();
 
 	udelay(40);	/* maintain the strobe during 40 us */
 
-	bits.e = BIT_CLR;
+	clear_bit(LCD_BIT_E, bits);
 	set_ctrl_bits();
 
 	udelay(120);	/* the shortest command takes at least 120 us */
···
 	w_dtr(pprt, data);
 	udelay(20);	/* maintain the data during 20 us before the strobe */
 
-	bits.e = BIT_SET;
-	bits.rs = BIT_SET;
-	bits.rw = BIT_CLR;
+	set_bit(LCD_BIT_E, bits);
+	set_bit(LCD_BIT_RS, bits);
+	clear_bit(LCD_BIT_RW, bits);
 	set_ctrl_bits();
 
 	udelay(40);	/* maintain the strobe during 40 us */
 
-	bits.e = BIT_CLR;
+	clear_bit(LCD_BIT_E, bits);
 	set_ctrl_bits();
 
 	udelay(45);	/* the shortest data takes at least 45 us */
···
 		/* maintain the data during 20 us before the strobe */
 		udelay(20);
 
-		bits.e = BIT_SET;
-		bits.rs = BIT_SET;
-		bits.rw = BIT_CLR;
+		set_bit(LCD_BIT_E, bits);
+		set_bit(LCD_BIT_RS, bits);
+		clear_bit(LCD_BIT_RW, bits);
 		set_ctrl_bits();
 
 		/* maintain the strobe during 40 us */
 		udelay(40);
 
-		bits.e = BIT_CLR;
+		clear_bit(LCD_BIT_E, bits);
 		set_ctrl_bits();
 
 		/* the shortest data takes at least 45 us */