/*
* linux/drivers/video/bt431.h
*
* Copyright 2003 Thiemo Seufer <seufer@csv.ica.uni-stuttgart.de>
*
* 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>
#include <asm/system.h>
/*
* Bt431 cursor generator registers, 32-bit aligned.
* Two twin Bt431 are used on the DECstation's PMAG-AA.
*/
struct bt431_regs {
volatile u16 addr_lo;
u16 pad0;
volatile u16 addr_hi;
u16 pad1;
volatile u16 addr_cmap;
u16 pad2;
volatile u16 addr_reg;
u16 pad3;
};
static inline u16 bt431_set_value(u8 val)
{
return ((val << 8) | (val & 0xff)) & 0xffff;
}
static inline u8 bt431_get_value(u16 val)
{
return val & 0xff;
}
/*
* Additional registers addressed indirectly.
*/
#define BT431_REG_CMD 0x0000
#define BT431_REG_CXLO 0x0001
#define BT431_REG_CXHI 0x0002
#define BT431_REG_CYLO 0x0003
#define BT431_REG_CYHI 0x0004
#define BT431_REG_WXLO 0x0005
#define BT431_REG_WXHI 0x0006
#define BT431_REG_WYLO 0x0007
#define BT431_REG_WYHI 0x0008
#define BT431_REG_WWLO 0x0009
#define BT431_REG_WWHI 0x000a
#define BT431_REG_WHLO 0x000b
#define BT431_REG_WHHI 0x000c
#define BT431_REG_CRAM_BASE 0x0000
#define BT431_REG_CRAM_END 0x01ff
/*
* Command register.
*/
#define BT431_CMD_CURS_ENABLE 0x40
#define BT431_CMD_XHAIR_ENABLE 0x20
#define BT431_CMD_OR_CURSORS 0x10
#define BT431_CMD_AND_CURSORS 0x00
#define BT431_CMD_1_1_MUX 0x00
#define BT431_CMD_4_1_MUX 0x04
#define BT431_CMD_5_1_MUX 0x08
#define BT431_CMD_xxx_MUX 0x0c
#define BT431_CMD_THICK_1 0x00
#define BT431_CMD_THICK_3 0x01
#define BT431_CMD_THICK_5 0x02
#define BT431_CMD_THICK_7 0x03
static inline void bt431_select_reg(struct bt431_regs *regs, int ir)
{
/*
* The compiler splits the write in two bytes without these
* helper variables.
*/
volatile u16 *lo = &(regs->addr_lo);
volatile u16 *hi = &(regs->addr_hi);
mb();
*lo = bt431_set_value(ir & 0xff);
wmb();
*hi = bt431_set_value((ir >> 8) & 0xff);
}
/* Autoincrement read/write. */
static inline u8 bt431_read_reg_inc(struct bt431_regs *regs)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_reg);
mb();
return bt431_get_value(*r);
}
static inline void bt431_write_reg_inc(struct bt431_regs *regs, u8 value)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_reg);
mb();
*r = bt431_set_value(value);
}
static inline u8 bt431_read_reg(struct bt431_regs *regs, int ir)
{
bt431_select_reg(regs, ir);
return bt431_read_reg_inc(regs);
}
static inline void bt431_write_reg(struct bt431_regs *regs, int ir, u8 value)
{
bt431_select_reg(regs, ir);
bt431_write_reg_inc(regs, value);
}
/* Autoincremented read/write for the cursor map. */
static inline u16 bt431_read_cmap_inc(struct bt431_regs *regs)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_cmap);
mb();
return *r;
}
static inline void bt431_write_cmap_inc(struct bt431_regs *regs, u16 value)
{
/*
* The compiler splits the write in two bytes without the
* helper variable.
*/
volatile u16 *r = &(regs->addr_cmap);
mb();
*r = value;
}
static inline u16 bt431_read_cmap(struct bt431_regs *regs, int cr)
{
bt431_select_reg(regs, cr);
return bt431_read_cmap_inc(regs);
}
static inline void bt431_write_cmap(struct bt431_regs *regs, int cr, u16 value)
{
bt431_select_reg(regs, cr);
bt431_write_cmap_inc(regs, value);
}
static inline void bt431_enable_cursor(struct bt431_regs *regs)
{
bt431_write_reg(regs, BT431_REG_CMD,
BT431_CMD_CURS_ENABLE | BT431_CMD_OR_CURSORS
| BT431_CMD_4_1_MUX | BT431_CMD_THICK_1);
}
static inline void bt431_erase_cursor(struct bt431_regs *regs)
{
bt431_write_reg(regs, BT431_REG_CMD, BT431_CMD_4_1_MUX);
}
static inline void bt431_position_cursor(struct bt431_regs *regs, u16 x, u16 y)
{
/*
* Magic from the MACH sources.
*
* Cx = x + D + H - P
* P = 37 if 1:1, 52 if 4:1, 57 if 5:1
* D = pixel skew between outdata and external data
* H = pixels between HSYNCH falling and active video
*
* Cy = y + V - 32
* V = scanlines between HSYNCH falling, two or more
* clocks after VSYNCH falling, and active video
*/
x += 412 - 52;
y += 68 - 32;
/* Use autoincrement. */
bt431_select_reg(regs, BT431_REG_CXLO);
bt431_write_reg_inc(regs, x & 0xff); /* BT431_REG_CXLO */
bt431_write_reg_inc(regs, (x >> 8) & 0x0f); /* BT431_REG_CXHI */
bt431_write_reg_inc(regs, y & 0xff); /* BT431_REG_CYLO */
bt431_write_reg_inc(regs, (y >> 8) & 0x0f); /* BT431_REG_CYHI */
}
static inline void bt431_set_font(struct bt431_regs *regs, u8 fgc,
u16 width, u16 height)
{
int i;
u16 fgp = fgc ? 0xffff : 0x0000;
u16 bgp = fgc ? 0x0000 : 0xffff;
bt431_select_reg(regs, BT431_REG_CRAM_BASE);
for (i = BT431_REG_CRAM_BASE; i <= BT431_REG_CRAM_END; i++) {
u16 value;
if (height << 6 <= i << 3)
value = bgp;
else if (width <= i % 8 << 3)
value = bgp;
else if (((width >> 3) & 0xffff) > i % 8)
value = fgp;
else
value = fgp & ~(bgp << (width % 8 << 1));
bt431_write_cmap_inc(regs, value);
}
}
static inline void bt431_init_cursor(struct bt431_regs *regs)
{
/* no crosshair window */
bt431_select_reg(regs, BT431_REG_WXLO);
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WXHI */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WYHI */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WWHI */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHLO */
bt431_write_reg_inc(regs, 0x00); /* BT431_REG_WHHI */
}
