auxdisplay: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul Burton <paul.burton@mips.com>
Tested-by: Paul Burton <paul.burton@mips.com> # for img-ascii-lcd

drivers/auxdisplay/img-ascii-lcd.c

@@ -229,9 +229,9 @@ MODULE_DEVICE_TABLE(of, img_ascii_lcd_matches);
  * Scroll the current message along the LCD by one character, rearming the
  * timer if required.
  */
-static void img_ascii_lcd_scroll(unsigned long arg)
+static void img_ascii_lcd_scroll(struct timer_list *t)
 {
-	struct img_ascii_lcd_ctx *ctx = (struct img_ascii_lcd_ctx *)arg;
+	struct img_ascii_lcd_ctx *ctx = from_timer(ctx, t, timer);
 	unsigned int i, ch = ctx->scroll_pos;
 	unsigned int num_chars = ctx->cfg->num_chars;
 
@@ -299,7 +299,7 @@ static int img_ascii_lcd_display(struct img_ascii_lcd_ctx *ctx,
 	ctx->scroll_pos = 0;
 
 	/* update the LCD */
-	img_ascii_lcd_scroll((unsigned long)ctx);
+	img_ascii_lcd_scroll(&ctx->timer);
 
 	return 0;
 }
@@ -395,9 +395,7 @@ static int img_ascii_lcd_probe(struct platform_device *pdev)
 	ctx->scroll_rate = HZ / 2;
 
 	/* initialise a timer for scrolling the message */
-	init_timer(&ctx->timer);
-	ctx->timer.function = img_ascii_lcd_scroll;
-	ctx->timer.data = (unsigned long)ctx;
+	timer_setup(&ctx->timer, img_ascii_lcd_scroll, 0);
 
 	platform_set_drvdata(pdev, ctx);
 

drivers/auxdisplay/panel.c

@@ -1396,7 +1396,7 @@ static void panel_process_inputs(void)
 	}
 }
 
-static void panel_scan_timer(void)
+static void panel_scan_timer(struct timer_list *unused)
 {
 	if (keypad.enabled && keypad_initialized) {
 		if (spin_trylock_irq(&pprt_lock)) {
@@ -1421,7 +1421,7 @@ static void init_scan_timer(void)
 	if (scan_timer.function)
 		return;		/* already started */
 
-	setup_timer(&scan_timer, (void *)&panel_scan_timer, 0);
+	timer_setup(&scan_timer, panel_scan_timer, 0);
 	scan_timer.expires = jiffies + INPUT_POLL_TIME;
 	add_timer(&scan_timer);
 }