6aa7de0591
Please do not apply this to mainline directly, instead please re-run the
coccinelle script shown below and apply its output.
For several reasons, it is desirable to use {READ,WRITE}_ONCE() in
preference to ACCESS_ONCE(), and new code is expected to use one of the
former. So far, there's been no reason to change most existing uses of
ACCESS_ONCE(), as these aren't harmful, and changing them results in
churn.
However, for some features, the read/write distinction is critical to
correct operation. To distinguish these cases, separate read/write
accessors must be used. This patch migrates (most) remaining
ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following
coccinelle script:
----
// Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and
// WRITE_ONCE()
// $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch
virtual patch
@ depends on patch @
expression E1, E2;
@@
- ACCESS_ONCE(E1) = E2
+ WRITE_ONCE(E1, E2)
@ depends on patch @
expression E;
@@
- ACCESS_ONCE(E)
+ READ_ONCE(E)
----
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: davem@davemloft.net
Cc: linux-arch@vger.kernel.org
Cc: mpe@ellerman.id.au
Cc: shuah@kernel.org
Cc: snitzer@redhat.com
Cc: thor.thayer@linux.intel.com
Cc: tj@kernel.org
Cc: viro@zeniv.linux.org.uk
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
/*
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* Driver for the LCD display on the Tensilica XTFPGA board family.
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* http://www.mytechcorp.com/cfdata/productFile/File1/MOC-16216B-B-A0A04.pdf
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001, 2006 Tensilica Inc.
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* Copyright (C) 2015 Cadence Design Systems Inc.
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*/
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <platform/hardware.h>
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#include <platform/lcd.h>
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/* LCD instruction and data addresses. */
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#define LCD_INSTR_ADDR ((char *)IOADDR(CONFIG_XTFPGA_LCD_BASE_ADDR))
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#define LCD_DATA_ADDR (LCD_INSTR_ADDR + 4)
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#define LCD_CLEAR 0x1
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#define LCD_DISPLAY_ON 0xc
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/* 8bit and 2 lines display */
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#define LCD_DISPLAY_MODE8BIT 0x38
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#define LCD_DISPLAY_MODE4BIT 0x28
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#define LCD_DISPLAY_POS 0x80
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#define LCD_SHIFT_LEFT 0x18
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#define LCD_SHIFT_RIGHT 0x1c
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static void lcd_put_byte(u8 *addr, u8 data)
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{
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#ifdef CONFIG_XTFPGA_LCD_8BIT_ACCESS
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WRITE_ONCE(*addr, data);
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#else
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WRITE_ONCE(*addr, data & 0xf0);
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WRITE_ONCE(*addr, (data << 4) & 0xf0);
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#endif
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}
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static int __init lcd_init(void)
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{
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WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
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mdelay(5);
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WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
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udelay(200);
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WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
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udelay(50);
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#ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS
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WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT);
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udelay(50);
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lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT);
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udelay(50);
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#endif
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lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_ON);
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udelay(50);
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lcd_put_byte(LCD_INSTR_ADDR, LCD_CLEAR);
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mdelay(10);
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lcd_disp_at_pos("XTENSA LINUX", 0);
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return 0;
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}
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void lcd_disp_at_pos(char *str, unsigned char pos)
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{
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lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_POS | pos);
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udelay(100);
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while (*str != 0) {
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lcd_put_byte(LCD_DATA_ADDR, *str);
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udelay(200);
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str++;
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}
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}
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void lcd_shiftleft(void)
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{
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lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_LEFT);
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udelay(50);
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}
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void lcd_shiftright(void)
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{
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lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_RIGHT);
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udelay(50);
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}
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arch_initcall(lcd_init);
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