Re: [PATCH v2] staging: panel: change struct bits to a bit array

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Moreover, you introduced another issue.
See below.

CJ

Le 14/03/2015 00:20, Isaac Lleida a écrit :
This path implements a bit array representing the LCD signal states instead of the old "struct bits", which used char to represent a single bit. This will reduce the memory usage.

Signed-off-by: Isaac Lleida <illeida@xxxxxxxxxxxxxxxx
---
v2: fix some stupid errors from the first patch

  drivers/staging/panel/panel.c | 86 ++++++++++++++++++++++++-------------------
  1 file changed, 49 insertions(+), 37 deletions(-)

diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index 3339633..9c76c0e 100644
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -310,6 +310,25 @@ static int selected_lcd_type = NOT_SET;
  #define LCD_BITS	6
/*
+ * LCD signal states
+ */
+#define LCD_BIT_E_MASK		0x1	/* E (data latch on falling edge) */
+#define LCD_BIT_RS_MASK		0x2	/* RS  (0 = cmd, 1 = data) */
+#define LCD_BIT_RW_MASK		0x4	/* R/W (0 = W, 1 = R) */
+#define LCD_BIT_BL_MASK		0x8	/* backlight (0 = off, 1 = on) */
+#define LCD_BIT_CL_MASK		0x10	/* clock (latch on rising edge) */
+#define LCD_BIT_DA_MASK		0x20	/* data */
+
+/*
+ * Bit array operations
+ */
+#define BIT_ON(b, m)	(b |= m)
+#define BIT_OFF(b, m)	(b &= ~m)
+#define BIT_CHK(b, m)	(b & m)
+#define BIT_MOD(b, m, v)				\
+	(((v) ? BIT_ON(b, m) : BIT_OFF(b, m))?1:0)	\
+
+/*
   * each bit can be either connected to a DATA or CTRL port
   */
  #define LCD_PORT_C	0
@@ -653,15 +672,8 @@ static const char nexcom_keypad_profile[][4][9] = {
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;
+/* Bit array containing signals states */
+static char bits;
static void init_scan_timer(void); @@ -674,12 +686,12 @@ static int set_data_bits(void)
  	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];
+	val |= lcd_bits[LCD_PORT_D][LCD_BIT_E][BIT_CHK(bits, LCD_BIT_E_MASK)]
+	    | lcd_bits[LCD_PORT_D][LCD_BIT_RS][BIT_CHK(bits, LCD_BIT_RS_MASK)]
+	    | lcd_bits[LCD_PORT_D][LCD_BIT_RW][BIT_CHK(bits, LCD_BIT_RW_MASK)]
+	    | lcd_bits[LCD_PORT_D][LCD_BIT_BL][BIT_CHK(bits, LCD_BIT_BL_MASK)]
+	    | lcd_bits[LCD_PORT_D][LCD_BIT_CL][BIT_CHK(bits, LCD_BIT_CL_MASK)]
+	    | lcd_bits[LCD_PORT_D][LCD_BIT_DA][BIT_CHK(bits, LCD_BIT_DA_MASK)];
w_dtr(pprt, val);
  	return val;
@@ -694,12 +706,12 @@ static int set_ctrl_bits(void)
  	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];
+	val |= lcd_bits[LCD_PORT_C][LCD_BIT_E][BIT_CHK(bits, LCD_BIT_E_MASK)]
+	    | lcd_bits[LCD_PORT_C][LCD_BIT_RS][BIT_CHK(bits, LCD_BIT_RS_MASK)]
+	    | lcd_bits[LCD_PORT_C][LCD_BIT_RW][BIT_CHK(bits, LCD_BIT_RW_MASK)]
+	    | lcd_bits[LCD_PORT_C][LCD_BIT_BL][BIT_CHK(bits, LCD_BIT_BL_MASK)]
+	    | lcd_bits[LCD_PORT_C][LCD_BIT_CL][BIT_CHK(bits, LCD_BIT_CL_MASK)]
+	    | lcd_bits[LCD_PORT_C][LCD_BIT_DA][BIT_CHK(bits, LCD_BIT_DA_MASK)];
w_ctr(pprt, val);
  	return val;
@@ -794,12 +806,12 @@ static void lcd_send_serial(int byte)
  	/* the data bit is set on D0, and the clock on STROBE.
  	 * LCD reads D0 on STROBE's rising edge. */
  	for (bit = 0; bit < 8; bit++) {
-		bits.cl = BIT_CLR;	/* CLK low */
+		BIT_OFF(bits, LCD_BIT_CL_MASK);	/* CLK low */
  		panel_set_bits();
-		bits.da = byte & 1;
+		BIT_MOD(bits, LCD_BIT_DA_MASK, byte & 1);
  		panel_set_bits();
  		udelay(2);  /* maintain the data during 2 us before CLK up */
-		bits.cl = BIT_SET;	/* CLK high */
+		BIT_ON(bits, LCD_BIT_CL_MASK);	/* CLK high */
  		panel_set_bits();
  		udelay(1);  /* maintain the strobe during 1 us */
  		byte >>= 1;
@@ -814,7 +826,7 @@ static void lcd_backlight(int on)
/* The backlight is activated by setting the AUTOFEED line to +5V */
  	spin_lock_irq(&pprt_lock);
-	bits.bl = on;
+	BIT_MOD(bits, LCD_BIT_BL_MASK, on);
  	panel_set_bits();
  	spin_unlock_irq(&pprt_lock);
  }
@@ -849,14 +861,14 @@ static void lcd_write_cmd_p8(int cmd)
  	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;
+	BIT_ON(bits, LCD_BIT_E_MASK);
+	BIT_ON(bits, LCD_BIT_RS_MASK);

This one should remain BIT_OFF as in your first post.

+	BIT_OFF(bits, LCD_BIT_RW_MASK);
  	set_ctrl_bits();
udelay(40); /* maintain the strobe during 40 us */ - bits.e = BIT_CLR;
+	BIT_OFF(bits, LCD_BIT_E_MASK);
  	set_ctrl_bits();
udelay(120); /* the shortest command takes at least 120 us */
@@ -871,14 +883,14 @@ static void lcd_write_data_p8(int data)
  	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;
+	BIT_ON(bits, LCD_BIT_E_MASK);
+	BIT_ON(bits, LCD_BIT_RS_MASK);
+	BIT_OFF(bits, LCD_BIT_RW_MASK);
  	set_ctrl_bits();
udelay(40); /* maintain the strobe during 40 us */ - bits.e = BIT_CLR;
+	BIT_OFF(bits, LCD_BIT_E_MASK);
  	set_ctrl_bits();
udelay(45); /* the shortest data takes at least 45 us */
@@ -968,15 +980,15 @@ static void lcd_clear_fast_p8(void)
  		/* maintain the data during 20 us before the strobe */
  		udelay(20);
- bits.e = BIT_SET;
-		bits.rs = BIT_SET;
-		bits.rw = BIT_CLR;
+		BIT_ON(bits, LCD_BIT_E_MASK);
+		BIT_OFF(bits, LCD_BIT_RS_MASK);
+		BIT_OFF(bits, LCD_BIT_RW_MASK);
  		set_ctrl_bits();
/* maintain the strobe during 40 us */
  		udelay(40);
- bits.e = BIT_CLR;
+		BIT_OFF(bits, LCD_BIT_E_MASK);
  		set_ctrl_bits();
/* the shortest data takes at least 45 us */

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