linux/drivers/video/fbdev/bt455.h

91 lines
1.8 KiB
C

/*
* linux/drivers/video/bt455.h
*
* Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
* Copyright 2016 Maciej W. Rozycki <macro@linux-mips.org>
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
#include <linux/types.h>
/*
* Bt455 byte-wide registers, 32-bit aligned.
*/
struct bt455_regs {
volatile u8 addr_cmap;
u8 pad0[3];
volatile u8 addr_cmap_data;
u8 pad1[3];
volatile u8 addr_clr;
u8 pad2[3];
volatile u8 addr_ovly;
u8 pad3[3];
};
static inline void bt455_select_reg(struct bt455_regs *regs, int ir)
{
mb();
regs->addr_cmap = ir & 0x0f;
}
static inline void bt455_reset_reg(struct bt455_regs *regs)
{
mb();
regs->addr_clr = 0;
}
/*
* Read/write to a Bt455 color map register.
*/
static inline void bt455_read_cmap_next(struct bt455_regs *regs, u8 *grey)
{
mb();
regs->addr_cmap_data;
rmb();
*grey = regs->addr_cmap_data & 0xf;
rmb();
regs->addr_cmap_data;
}
static inline void bt455_write_cmap_next(struct bt455_regs *regs, u8 grey)
{
wmb();
regs->addr_cmap_data = 0x0;
wmb();
regs->addr_cmap_data = grey & 0xf;
wmb();
regs->addr_cmap_data = 0x0;
}
static inline void bt455_write_ovly_next(struct bt455_regs *regs, u8 grey)
{
wmb();
regs->addr_ovly = 0x0;
wmb();
regs->addr_ovly = grey & 0xf;
wmb();
regs->addr_ovly = 0x0;
}
static inline void bt455_read_cmap_entry(struct bt455_regs *regs,
int cr, u8 *grey)
{
bt455_select_reg(regs, cr);
bt455_read_cmap_next(regs, grey);
}
static inline void bt455_write_cmap_entry(struct bt455_regs *regs,
int cr, u8 grey)
{
bt455_select_reg(regs, cr);
bt455_write_cmap_next(regs, grey);
}
static inline void bt455_write_ovly_entry(struct bt455_regs *regs, u8 grey)
{
bt455_reset_reg(regs);
bt455_write_ovly_next(regs, grey);
}